• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.1
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• pp.48-56
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• 2009

This paper presents the results of miniaturized micro milling machine tool development for micro precision machining process. Finite element analysis has been performed to know the relationship between design dimensional variables and structural stiffness in terms of static, dynamic, thermal aspects. Design optimization has been performed to optimize the design variables of micro machine tool to minimize the volume, weight and deformation of machine tool structure and to maximize the stiffness in terms of static, dynamic, and thermal characteristics. This study presents the assessment of the technology incentive for the minimization of machine tool in the quantitative context of static, dynamic stiffness, thermal resistance and thus the accuracy implications. This study can also be provided a basic knowledge for further research of micro factory development.

• Steel and Composite Structures
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• v.3 no.5
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• pp.349-369
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• 2003

The paper concerns the modelling of rigid and semi-rigid steel-concrete composite joints under monotonic loading through use of the Abaqus program, a widespread finite element code. By comparing numerical and experimental results obtained on cruciform tests, it is shown that the proposed modelling allows a good fit of the global joint response in terms of moment-rotation law. Even the local response in terms of stresses and strains is adequately predicted. Hence, this numerical approach may represent a useful tool for attaining a better understanding of experimental results. It may also be used to perform parametric analyses and to calibrate simplified mechanical models for practical applications.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.45-52
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• 2003

A finite element procedure to estimate ultimate strength of space frames considering spread of plasticity is presented. The improved displacement field is introduced based on inclusion of second order terms of finite rotations. All the nonlinear terms due to bending and torsional moment as well as axial force are precisely considered. The concept of plastic hinge is introduced and the incremental load/displacement method is applied for the elasto-plastic analysis. The initial yield surface is defined based on the residual stress and the full plastification surface is considered under the combined action of axial force, bending and torsional moments. The elasto-plastic stiffness matrices are derived using the flow rule and the normality condition of the limit function. Finite element solutions for ultimate strength of space frames are compared with available solutions and experimental results.

• English Language & Literature Teaching
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• v.10 no.3
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• pp.159-175
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• 2004

This paper investigated the types of errors on English pronunciation and intelligibility of Korean EFL students, and the relationship between the pronunciation accuracy and intelligibility. Thirty one students were evaluated by six English native speakers in terms of overall intelligibility and accuracy In five areas such as nuclear stress, word stress, syllable structure, consonants and vowels. According to the findings of the study, pronunciation errors were made by the subjects more frequently In word stress than any other area of pronunciation accuracy. The Pearson correlation analysis showed that intelligibility was related with word stress, syllable structure, consonants and vowels, and the stepwise multiple regression analysis indicated that, among the above five areas of pronunciation accuracy, word stress best accounted for the intelligibility of a given sentence. In the conclusion, the importance of teaching pronunciation of in those five areas with a special focus on word stress was emphasized m terms of intelligibility.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.9
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• pp.133-144
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• 2000

The dynamic walking planning and the inverse dynamics of the biped robot is investigated in this paper. The biped robot is modeled with 14 degrees of freedom rigid bodies considering the walking pattern and kinematic construction of humanoid. The method of the computer aided multibody dynamics is applied to the dynamic analysis. The equations of motion of biped are initially represented as terms of the Cartesian corrdinates then they are converted to the minimum number of equations of motion in terms of the joint coordinates using the velocity transformation matrix. For the consideration of the relationships between the ground and foot the holonomic constraints are added or deleted on the equations of motion. the number of these constraints can be changed by types of walking patterns with three modes. In order for the dynamic walking to be stabilizable optimized trunk positions are iteratively determined by satisfying the system ZMP(Zero Moment Point) and ground conditions.

• Journal of the Korean Home Economics Association
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• v.40 no.5
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• pp.147-158
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• 2002

This study was intended to make an analysis of the classification of Internet consumer information provided on the Internet and its realities with a focus on the realities of information characteristics and technological level to provide systematized consumer information for consumers. As a result, the following findings were obtained: First, it was found that information on consumer panel research, anti-site and consumerism is lacking in terms of the type of information currently provided in the Internet consumer information classification. Second, it was found that up-to-datensess, communically and connectivity were high in the level of Internet consumer information characteristics. Third, it was found that publicity was realities well carried out in terms of the technological level of Internet consumer information but that the realities of publicity was still tacking. Fourth, it is thought that it is necessary to construct the Internet consumer information provision site through several eve-level programs for elementary, middle and high school students in a systematic fashion in order to provide diverse consumers with Internet consumer information at several levels.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.11
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• pp.2704-2710
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• 1993

A simple and straightforward method is introduced for developing continuum beam-rod model of a box-beam typed aircraft wing with composite layered skin based on "energy equivalence." The equivalent continuum structral properties are obtained from the direct comparison of the reduced stiffness and mass matrices for box-beam typed wing with those for continuum beam-rod model. The stiffness and mass matrices are all represented in terms of the continuum degrees-of freedom defined in this paper. The finite-element method. The advantage of the present continuum method is to give every continuum structural properties including all possible coupling terms which represent the couplings between different deformations. To evaluate the continuum method developed in this paper, free vibration analyses for both continuum beam-rod and box-beam are conducted. Numerical tests show that the present continuum method gives very reliable structural and dynamic properties compared to the results by the conventional finite-element analysis. analysis.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.548-555
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• 2000

The dynamic walking and the inverse dynamics of the biped walking robot is investigated in this paper. The biped robot is modeled with 14 degrees of freedom rigid bodies considering the walking pattern and kinematic construction of humanoid. The method of the computer aided multibody dynamics is applied to the dynamic analysis. The equations of motion of biped are initially represented as terms of the Cartesian coordinates, then they are converted to the minimum number of equations of motion in terms of the joint coordinates using the velocity transformation matrix. For the consideration of the relationships between the ground and foot, the holonomic constraints are added or deleted on the equations of motion. The number of these constraints can be changed by types of walking pattern with three modes. In order for the dynamic walking to be stabilizable, optimized trunk positions are iteratively determined by satisfying the system ZMP(Zero Moment Point) and ground conditions.

• Journal of the Korean Institute of Navigation
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• v.25 no.1
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• pp.11-22
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• 2001

Nowadays, it is planning to establish a coastal VTS in Korean southern coastal waters in order to enhance the safety of vessel traffic and to protect the marine environment. But, it surely needs over ten billions Won to establish, operate and maintain the above mentioned coastal VTS. Therefore, this paper proposes the VTS cost-benefit analysis model to confirm the reasonability and decide the priority of the project. This model has three distinct processes. Fist, it is the identification in qualitative terms of the effects of a given proposal. Second, it quantify the specified effects in physical terms. Third, it is the evaluation of the total effects of project. The proposed model in this Paper will contribute to the confirmation and the priority of the project in future.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.2
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• pp.177-188
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• 2012

GIS provides the various analyzing and displaying using diverse spatial data have supported the powerful functionality and friendly user-interface. But, early GIS software is developed as package tool, it have many difficulties with reducing the cost of developing GPS application and satisfying the various user requirements. At present, the developed GPS applications across multiple domains, despite the common features are built separately for each domain in terms of software engineering development followed out waste of time and money expenditure. However, common features between GPS applications, if deployed as a component assembly and reuse components in terms of enabling the two kinds of component-based development can bring out the beneficial results. In this paper, we described the Analysis and design of GPS ApplicationsS based on Component. Each GPS component is composed of many objects accomplish the atomic service processing and cooperate with each other. And, GPS components meets the qualifications of thc low cost of developing GPS application because of the reusability and re-composition.