• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.178-181
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• 1995

In this paper, on-line adaptive friction compensation scheme for the precise position control is presented. 2 DOF system with compliance and friction is used for the plant model. In order to reduce the calculation time for the parameter estimation, 1 DOF estimation model is used. The computer simulation and experimental results show the validity of the supposed scheme.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.173-176
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• 2002

Viscoplastic deformation and sheet forming behavior of multicomponent Zr-based bulk metallic glass alloy has been investigated. From a series of mechanical test results, basic processing maps based on Dynamic Materials Model have been constructed to establish feasible forming conditions. Stamping in laboratory scale was then performed at the various stroke speeds and temperatures using a hydraulic press. Failure in macroscopic level was examined to check the validity of constructed processing maps.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.141-148
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• 1998

An analytical model which can simulate the post-cracking behavior of reinforced concrete structures subjected to in-plane shear and normal stresses is presented. Based on the force equilibriums, compatibility conditions, and bond stress-slip relationship between steel and concrete, a criterion to simulate consider the tension-stiffening effect is proposed. The material behavior of concrete is described by an orthotropic constitutive model, and focused on the tension-compression region with tension-stiffening and compression softening effects defining equivalent uniaxial relations in the axes of orthotropy. Correlation studies between analytical results and available experimental data are conducted with the objective to establish the validity of the proposed model.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.514-519
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• 2001

Most of inverters adopt a diode rectifier as an input stage, which has very simple and rugged structure and therefore low cost. In order to properly design the 3-phase diode rectifier with an output smoothing capacitor and input inductors, it is necessary to fully simulate the system due to its nonlinear characteristics. Therefore this paper describes the operating behaviors including the current commutation in detail by using the proposed equivalent circuit, and also proposes the Simulink-based model of the system. The simulation results show the validity of the proposed model in all operating conditions.

• Journal of Information Technology and Architecture
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• v.9 no.1
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• pp.21-31
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• 2012

We focus on the issues of the non-linear return/risk relationship of IT investment and the balance between return and risk of IT portfolio. We develop an IT project selection model by integrating DEA models with Markowitz portfolio selection theory. The project data collected from a Fortune 100 company are used to illustrate the implementation of the model. In addition, computational experiments are conducted to demonstrate the validity of the proposed model.

• Korean Journal of Culture and Social Issue
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• v.26 no.3
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• pp.259-282
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• 2020

This study examines the validity of the Filial Responsibility Scale-Adult (Past), developed by Jurkovic and Thirkield (1999), among Korean university students in their twenties. First, a preliminary scale consisting of 30 items was developed by translating the original scale into Korean and item analysis and exploratory factor analysis were conducted on 249 subjects. Based on the exploratory factor analysis, items in the emotional parentification factor were either deleted or included in the other remaining factors, resulting in a two-factor model containing 15 items. In order to confirm this, a confirmatory factor analysis was conducted on 318 independent subjects. As a result of a confirmatory factor analysis of the two competing models - the three-factor model consisting of 30 items based on the original scale and the two-factor(emotional experience and caring behavior) model consisting of 15 items gained as a result of the exploratory factor analysis - the two-factor model showed more suitable and the original scale was revised accordingly. The convergent validity, discriminant validity and predictive validity were all found to be satisfactory. Based on such results, implications, limitations and suggestions on follow-up studies are discussed.

• Journal of Information Technology Applications and Management
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• v.19 no.2
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• pp.117-134
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• 2012

Cluster industries are geographically concentrated and inter-connected by the flow of goods and services, which is stronger than the flow linking them to the rest of the economy. Photonics industries are one of the fastest growing high-tech industries in the world today. Especially, the city of Gwangju(South Korea) industrial cluster, a specialized complex in photonics industry, produced remarkable results in developing high-quality technologies since it launched the cluster program in 2005. Gwangju photonics industrial cluster will be ranked top level of the world photonics industry. In this sense, this study is aimed at proposing a new research model in which corporate performance influence factors of photonics industrial cluster (i.e., business environment, cooperative relationship, and industry-university-research institute partnership) affect absorptive capacity positively, leading to corporate performance eventually. This study developed a research model to explain the Korean photonics industrial cluster effects, and collected 91 survey responses from photonics based company managers in industrial cluster complex. To prove the validity of the proposed research model, PLS analysis is applied with valid 91 questionnaires. By employing PLS technique, the measurement reliability and validity of research variables are tested and the path analysis is conducted to do the hypothesis testing. In brief, the finding of this study suggests that corporate performance influence factors of photonics industrial cluster affect absorptive capacity positively, and corporate performance as well.

• Journal of Power System Engineering
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• v.20 no.6
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• pp.20-26
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• 2016

For power electronic devices, the thermal energy density per unit volume has seen a rapid increase in recent years, owing to the miniaturization and dense integration of electronic components, as well as the continuous development in performance and function. This research examined the validity and reliability of a thermal safety model for managing the heating conditions of TRIAC electronic components. Among the electronic components of a PCB, these can be considered as a heat source. Using the model, the heating conditions of TRIAC components were maintained at their design target levels in the process of developing an LMT motor drive board. In addition, the heating characteristics of the entire PCB were analyzed to verify its thermal safety. Finally, the reliability and validity of the thermal safety model for maintaining the heating conditions of the TRIAC electronic elements at adequate levels was verified using a numerical analysis method.

• Journal of Information Technology Services
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• v.3 no.1
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• pp.21-41
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• 2004

The technical proposal suggested and published by MIC(Ministry of Information and Communication, henceforth MIC) contains too general assessment elements, which causes qualitative and subjective assessment of technical proposals. Thus, in terms of the technical proposal assessment. It lacks In fairness, validity and accuracy. Furthermore, it has a great deal of difficulty in assessment caused by the inconsistency between proposal planning and assessment methods. Also, each company has different writing format, so it is impossible to make use of its maneuvering data for the assessment. To overcome these weaknesses, our research focused on a quantitative evaluation on development organization, which is a part of organizational and administrative part of the technical proposal suggested and published by MIC. In this research, we divided development organization for the technical proposal into organization, teams, and team members, and then studied addition, deletion and merging for the assessment criteria. For the related study, we chose especially CMM(Capability Maturity Model) from a lot of international and national references, which is a model measuring the maturity of organization, and then we focused on Small-CMM which is available in the small-sized organization. We also suggested input form, description method, assessment elements for the quantitative assessment in the chosen developmental organization, and finally we proposed standard referencing criteria for the assessment. Our study concludes that our assessment method are valid and available in comparison with the previous Delphi method through a validity evaluation test.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.2
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• pp.49-56
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• 2003

The welding deformation of a hull structure in the shipbuilding industry is Inevitable at each assembly stage. The geometric inaccuracy caused by the welding deformation tends to preclude the introduction of automation and mechanization and needs the additional man-hours for the adjusting work at the following assembly stage. To overcome this problem, a distortion control method should be applied. For this purpose, it is necessary to develop an accurateprediction method which can explicitly account for the influence of various factors on the welding deformation. The validity of the prediction method must be also clarified through experiments. This paper is aimed at deriving the simple prediction model for fillet welding deformations. For this purpose, the thermal elasto-plastic analysis varying the welding conditions and plate thickness has been performed. On the basis of numerical results, the formulae for angular distortion and transverse shrinkage have been derived through the regression analysis. Experimental work has been also carried out to clarify the validity of numerical results. It has been found that the numerical results show a good agreement with those of experiments