• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.343-349
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• 2017

In this study, the factors of the industrial complexes were analyzed in a comprehensive review, and the research model was developed and related variables were adopted to the purpose of this study. Also, the determinants of location are analyzed by three factors of infrastructure stabilization, industrial resource access, and residential neighborhood factors. For the analysis of this study, the hypothesis was analyzed through the path analysis of the SEM through the set hypotheses based on the research model. As a result of analysis, it is analyzed that TI factors and RA factors of infrastructure, IF group, are both influenced by industrial location. In addition, there is a statistically significant correlation in the analysis between the parameters of the NEF and the determinants of industrial location. The results of this study are expected to provide useful guidelines for industrial infrastructure development and industrial complex development projects at national and local government.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.261-269
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• 2009

This study was to analyze the effect of market orientation on service quality and business performance in the firms of private security guards. To attain the goal of the study described above paragraphs, some peoples held in Seoul were set as a collected group. Then, using the purposive sampling method, finally drew out and analyzed 235 peoples in total. The material collection device was the brochure named . The result of reliability check up was here below; Chronbach' $\alpha$=.732. To analyze materials, reliability analysis, SEM were used as statistic analysis techniques. The conclusion based on above study method and the result of material analysis are here below. First, market orientation have influence on service quality. Second, market orientation have influence on business performance. Third, service quality have influence on business performance.

• Journal of Internet Computing and Services
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• v.12 no.4
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• pp.145-156
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• 2011

The purpose of the study is to analyze the factors which cause the deviations of e-piracy. For this, empirical data were collected by conducing a field survey with a total of 531 collegians, and a Structural Equation Model was used for the purpose of analyzing the data acquired by that. A Structural Equation Model was designed and constructed by such factors as Anonymous Environment, Norm-Consciousness, and Recognition on Penalty, which are considered as the direct variables. In addition, the factor of Anonymous Environment was set as a variable for the factors of both Norm-Consciouness and Recoginition on Penalty. These are the results of the analysis; it is found that Anonymous Environment is the direct cause of e-piracy, but the other two factors are not statistically significant. And it is also found that Anonymous Environment gives a direct influence on the other factors of Norm-Consciousness and Recognition on Penalty and it also gives indirect influence on the factor of Recognition on Penalty by means of the factor of Norm-Consciousness. Therefore, in order to prevent e-piracy, it is required to provide the proper opportunity to be trained to observe norms under the environment of anonymity. For this, diverse and effectual teaching methods for information ethic education should be sought.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.10
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• pp.1861-1868
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• 1992

Laser beam hardening of 12%-Cr steel has been evaluated by using a continuous wave 3kW co$_{2}$ laser with a hardening mirror set. Experiment was performed on the hardening condition with a laser power of 2.85kW and travel speed of 1.0 and 1.5m/min. Multi passes have been also tried to find the hardening characteristics of partly overlapped zone. The black paint to use at high temperature was adopted to increase the absorptivity of laser beam energy with the wavelength of 10.6.mu.m at the surface of base metal. The microstructure of the hardened layers was observed by using a light microscopy, SEM and TEM. A fine Lamellar martensite formed in the hardened zones exhibits very high Vickers microhardness of 600Hv, whereas the tempered martensite distributes in the base metal with Vickers microhardness of 240Hv.It has been found that laser hardening with multi passes showed no significant drop of the hardness between adjacent passes.

• The Journal of the Korea Contents Association
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• v.11 no.7
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• pp.374-386
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• 2011

This study investigated the impact of leader's coaching on job satisfaction and job involvement. In particular, this study examined employees' self-efficacy as a mediator in the relationship between leader's coaching and job satisfaction and job involvement. On the basis of theoretical linkages between the constructs, a conceptual model and hypotheses were established. Empirical data were collected by using a set of questionnaires. This survey was administered to employees working in 20 firms. 269 samples were used for the analysis. This study conducted a exploratory factor analysis and confirmatory factor analysis for the validity test, structural equation modeling(SEM) was employed to test the hypothesized relationships in the conceptual model. This study shows that the proposed model is reasonably fit to the actual data. From these analyses, the following results were obtained. First, leader's coaching is positively related to employees' self-efficacy. Second, leader's coaching is positively related to job satisfaction and job involvement. Third, employees' self-efficacy has partially mediated effects on the relationship between leader's coaching and job satisfaction and job involvement.

• Structural Engineering and Mechanics
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• v.56 no.4
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• pp.549-567
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• 2015

A first-order moment method (FORM) reliability analysis is commonly used for structural stability analysis. It requires the values and partial derivatives of the performance to function with respect to the random variables for the design. These calculations can be cumbersome when the performance functions are implicit. A Gaussian process (GP)-based response surface is adopted in this study to approximate the limit state function. By using a trained GP model, a large number of values and partial derivatives of the performance functions can be obtained for conventional reliability analysis with a FORM, thereby reducing the number of stability analysis calculations. This dynamic renewed knowledge source can provide great assistance in improving the predictive capacity of GP during the iterative process, particularly from the view of machine learning. An iterative algorithm is therefore proposed to improve the precision of GP approximation around the design point by constantly adding new design points to the initial training set. Examples are provided to illustrate the GP-based response surface for both structural and non-structural reliability analyses. The results show that the proposed approach is applicable to structural reliability analyses that involve implicit performance functions and structural response evaluations that entail time-consuming finite element analyses.

• Structural Engineering and Mechanics
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• v.28 no.2
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• pp.129-152
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• 2008

This paper considers the solution of the stochastic differential equations (SDEs) with random operator and/or random excitation using the spectral SFEM. The random system parameters (involved in the operator) and the random excitations are modeled as second order stochastic processes defined only by their means and covariance functions. All random fields dealt with in this paper are continuous and do not have known explicit forms dependent on the spatial dimension. This fact makes the usage of the finite element (FE) analysis be difficult. Relying on the spectral properties of the covariance function, the Karhunen-Loeve expansion is used to represent these processes to overcome this difficulty. Then, a spectral approximation for the stochastic response (solution) of the SDE is obtained based on the implementation of the concept of generalized inverse defined by the Neumann expansion. This leads to an explicit expression for the solution process as a multivariate polynomial functional of a set of uncorrelated random variables that enables us to compute the statistical moments of the solution vector. To check the validity of this method, two applications are introduced which are, randomly loaded simply supported reinforced concrete beam and reinforced concrete cantilever beam with random bending rigidity. Finally, a more general application, randomly loaded simply supported reinforced concrete beam with random bending rigidity, is presented to illustrate the method.

• Structural Engineering and Mechanics
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• v.27 no.5
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• pp.625-638
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• 2007

The damage detection process may appear difficult to be implemented for truss structures because not all degrees of freedom in the numerical model can be experimentally measured. In this context, the damage locating vector (DLV) method, introduced by Bernal (2002), is a useful approach because it is effective when operating with an arbitrary number of sensors, a truncated modal basis and multiple damage scenarios, while keeping the calculation in a low level. In addition, the present paper also evaluates the noise influence on the accuracy of the DLV method. In order to verify the DLV behavior under different damages intensities and, mainly, in presence of measurement noise, a parametric study had been carried out. Different excitations as well as damage scenarios are numerically tested in a continuous Warren truss structure subjected to five noise levels with a set of limited measurement sensors. Besides this, it is proposed another way to determine the damage locating vectors in the DLV procedure. The idea is to contribute with an alternative option to solve the problem with a more widespread algebraic method. The original formulation via singular value decomposition (SVD) is replaced by a common solution of an eigenvector-eigenvalue problem. The final results show that the DLV method, enhanced with the alternative solution proposed in this paper, was able to correctly locate the damaged bars, using an output-only system identification procedure, even considering small intensities of damage and moderate noise levels.

• Structural Engineering and Mechanics
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• v.62 no.6
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• pp.749-758
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• 2017

In structural mechanics, traditional analyses methods usually employ matrix operations for obtaining displacement and internal forces of the structure under the external effects, such as distributed loads, earthquake or wind excitations, and temperature changing inter alia. These matrices are derived from the well-known principle of mechanics called minimum potential energy. According to this principle, a system can be in the equilibrium state only in case when the total potential energy of system is minimum. A close examination of the expression of the well-known equilibrium condition for linear problems, $P=K{\Delta}$, where P is the load vector, K is the stiffness matrix and ${\Delta}$ is the displacement vector, it is seen that, basically this principle searches the displacement set (or deformed shape) for a system that minimizes the total potential energy of it. Instead of using mathematical operations used in the conventional methods, with a different formulation, meta-heuristic algorithms can also be used for solving this minimization problem by defining total potential energy as objective function and displacements as design variables. Based on this idea the technique called Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) is proposed. The method has been successfully applied for linear and non-linear analyses of trusses and truss-like structures, and the results have shown that the approach is much more successful than conventional methods, especially for analyses of non-linear systems. In this study, the application of TPO/MA, with Harmony Search as the selected meta-heuristic algorithm, to cables net system is presented. The results have shown that the method is robust, powerful and accurate.

• Structural Engineering and Mechanics
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• v.67 no.4
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• pp.359-368
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• 2018

In this paper, a method is presented to identify the physical and modal parameters of multistory shear building based on substructural technique using block pulse generalized operational matrix and genetic algorithm. The substructure approach divides a complete structure into several substructures in order to significantly reduce the number of unknown parameters for each substructure so that identification processes can be independently conducted on each substructure. Block pulse functions are set of orthogonal functions that have been used in recent years as useful tools in signal characterization. Assuming that the input-outputs data of the system are known, their original BP coefficients can be calculated using numerical method. By using generalized BP operational matrices, substructural dynamic vibration equations can be converted into algebraic equations and based on BP coefficient for each story can be estimated. A cost function can be defined for each story based on original and estimated BP coefficients and physical parameters such as mass, stiffness and damping can be obtained by minimizing cost functions with genetic algorithm. Then, the modal parameters can be computed based on physical parameters. This method does not require that all floors are equipped with sensor simultaneously. To prove the validity, numerical simulation of a shear building excited by two different normally distributed random signals is presented. To evaluate the noise effect, measurement random white noise is added to the noise-free structural responses. The results reveal the proposed method can be beneficial in structural identification with less computational expenses and high accuracy.