• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.741-742
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• 2008

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.1
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• pp.20-25
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• 2012

A Crankshaft multi grinding machine is developed for manufacturing of high precision crankshaft. The grinding head part of the developed machine should be moved precisely during grinding of work materials. In this paper, structural and modal analysis for the crankshaft multi grinding machine is carried out to check the design criteria of the machine. The analysis is carried out by FEM simulation using the commercial software. The machine is modeled by placing proper shell and solid finite elements. The results of structural and modal analysis confirmed that the structural characteristics of grinding machine and the structural safety are considered secure.

• Journal of the Korean Home Economics Association
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• v.40 no.12
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• pp.1-11
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• 2002

This paper is intended as an analysis of the Chapter on Family in textbooks of a Middle school course at the aspect of Parson's Structural Functionalism Theory. In this analysis, We'd like to explore how the value of family is expressed in the Art-Home Economics textbooks. Generally, family is a subsystem in the structural system of whole society and family has two main functions to promote stability and equilibrium from the Parson's Structural Functionalism Theory point of view. Today, the concern with the Structural Functionalism Theory is dominantly reflected in textbooks, even though it has been proposed that the Structural Functionalism is not appropriate to explain family of modem society. Like that, the question now arises: the family history and interaction is ignored in the Structural Functionalism Theory. That is to say, There are limitations of Structural Functionalism Theory. The textbooks of Art-Home Economics was based on the revised curriculum has been severely changed in terms of external system of textbooks. But, we didn't know how much the view of the Structural Functionalism Theory is involved in textbooks. In this article, we analyze the view of the Structural Functionalism Theory in the Art- Home Economics textbooks using the Contents Analysis. At the same time, we find the confusion of family value revealed in textbooks.

• Smart Structures and Systems
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• v.19 no.5
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• pp.499-512
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• 2017

Traditional structural dynamic analysis and Structural Health Monitoring (SHM) of large scale concrete civil structures rely on manufactured embedding transducers to obtain structural dynamic properties. However, the embedding of manufactured transducers is very expensive and low efficiency for signal acquisition. In dynamic structural analysis and SHM areas, piezoelectric transducers are more and more popular due to the advantages like quick response, low cost and adaptability to different sizes. In this paper, the applicable feasibility assessment of the designed "artificial" piezoelectric transducers called Concrete Piezoelectric Smart Module (CPSM) in dynamic structural analysis is performed via three major experiments. Experimental Modal Analysis (EMA) based on Ibrahim Time Domain (ITD) Method is applied to experimentally extract modal parameters. Numerical modal analysis by finite element method (FEM) modeling is also performed for comparison. First ten order modal parameters are identified by EMA using CPSMs, PCBs and FEM modeling. Comparisons are made between CPSMs and PCBs, between FEM and CPSMs extracted modal parameters. Results show that Power Spectral Density by CPSMs and PCBs are similar, CPSMs acquired signal amplitudes can be used to predict concrete compressive strength. Modal parameter (natural frequencies) identified from CPSMs acquired signal and PCBs acquired signal are different in a very small range (~3%), and extracted natural frequencies from CPSMs acquired signal and FEM results are in an allowable small range (~5%) as well. Therefore, CPSMs are applicable for signal acquisition of dynamic responses and can be used in dynamic modal analysis, structural health monitoring and related areas.

• Transactions of Materials Processing
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• v.32 no.3
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• pp.129-135
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• 2023

The use of engineering plastic products in internal combustion engine and electric cars to improve stiffness and reduce weight is increasing significantly. Among various lightweight materials, engineering plastics have significant advantages such as cost reduction, improved productivity, and weight reduction. In particular, engineering plastics containing glass fibers are used to enhance stiffness. However, the stiffness of glass fibers can increase or decrease depending on their orientation. Before developing plastic products, optimal designs are determined through injection molding and structural analysis to enhance product reliability. However, reliable analysis of products with variable stiffnesses caused by anisotropy cannot be achieved via the conventional isotropic structural analysis, which does not consider anisotropy. Therefore, based on the previously reported study "the Effect of Impacted Fracture in Glass Fiber Orientation with Injection Molding & Structural Coupled Analysis," this study aims to investigate the structural analysis and degradation mechanisms of various polymers. In particular, this study elucidates the actual mechanism of plastic fracture by analyzing various fracture conditions and their corresponding simulations. Furthermore, the objective of this study is to apply the injection molding and structural coupled analysis mechanism to develop engineering plastic products containing glass fibers. In addition, the study aims to apply and improve the plastic fracture mechanism in actual products by exploring anisotropy and stiffness reduction owing to the unfilled polymer weld line.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.5
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• pp.421-432
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• 2012

This paper is the first paper among two papers which constitute the paper about the structural design of a dental implant. This paper surveyed types and characteristics of dental implants. Merits and shortcomings of clinically used dental implants were analysed through this survey. A new structural model of dental implant was proposed on the basis of survey results. Especially, a comparative structural analysis of the new dental implant and the well known dental implants has been performed using the finite element analysis method. The analysis results confirm that the newly proposed dental implant has a good structural performance. The well known dental implants used for the comparative structural analysis are 3i implant and Sargon implant. These implants are imported dental implants and we could know that most implants clinically used are endosteal implants and these two implants(3i implant and Sargon implant) are also endosteal implants.

• Journal of Aerospace System Engineering
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• v.12 no.3
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• pp.58-63
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• 2018

This work dealt with the design and manufacturing of composite blades of a vertical axis wind turbine system. In this work, aerodynamic and structural designs of sandwich composite blades for a vertical axis wind turbine system were performed. First, the aerodynamic and structural design requirements of the composite blades were investigated. After the structural design was complete, a structural analysis of the wind turbine blades was performed using the finite element analysis method. It was performed with the stress and displacement analysis at the applied load condition. A design modification for the structurally weak part was proposed as a result of the structural analysis. Through another structural analysis, it was confirmed that the final designed blade structure is safe.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.425-431
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• 2001

In order to take account of the statistical properties of probability variables used in the structural analysis, the conventional approach using the safety factor based on past experience usually estimated the safety of a structure. The real structures could only be analyzed with the error in estimation of loads, material characters and the dimensions of the members. But the errors should be considered systematically in the structural analysis. Structural safety could not precisely be appraised by the traditional structural design concept. Recently, new approach based on the probability concept has been applied to the assessment of structural safety using the reliability concept. In this study, safety of structures will estimated by the reliability analysis with commercial structural software that has the tools of nonlinear elastic-plastic 3-D analysis. Experimental test result is compared to results from this research and Coan/sup 1)/ In this paper, AFOSM(Advanced First-Order Second Moment method) is applied with von Mises, Tresca and Mohr-Coulomb failure criterions. The reliability index β and probability of failure P/sub f/ can be obtained by following this practical procedure as judgement a safety of structures and necessity of reinforcing.

• Journal of the Korean Society of Safety
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• v.28 no.1
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• pp.74-80
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• 2013

This study describes structural reliability analysis of actively-controlled structure for which random vibration analysis is incorporated into the first-order reliability method (FORM) framework. The existing approaches perform the reliability analysis based on the RMS response, whereas the proposed study uses the peak response for the reliability analysis. Therefore, the proposed approach provides us a meaningful performance measure of the active control system, i.e., realistic failure probability. In addition, it can deal with the uncertainties in the system parameters as well as the excitations in single-loop reliability analysis, whereas the conventional random vibration analysis requires double-loop reliability analysis; one is for the system parameters and the other is for stochastic excitations. The effectiveness of the proposed approach is demonstrated through a numerical example where the proposed approach shows fast and accurate reliability (or inversely failure probability) assessment results of the dynamical active control system against random seismic excitations in the presence of parametric uncertainties of the dynamical structural system.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.1
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• pp.89-94
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• 2005

The objective of this study is structural analysis of rope brake by spring type. The finite element model was developed to compute the stress, strain and friction force for rope brake by spring type. The ANSYS code was used for this analysis. In order to structural analysis of rope brake, many variables such as internal pressure, boundary condition load condition and constraints were considered.