• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.2
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• pp.291-298
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• 2022

Recently developed drones are inexpensive and very convenient to operate. As a result, the production and utilization of spatial information using drones are increasing. However, most drones acquire images with a low-cost global navigation satellite system (GNSS) and an inertial measurement unit (IMU). Accordingly, the accuracy of the initial location and rotation angle elements of the image is low. In addition, because these drones are small and light, they can be greatly affected by wind, making it difficult to maintain a certain overlap, which degrades the positioning accuracy. Therefore, in this study, images are taken at different times in order to analyze the positioning accuracy according to changes in certain exterior orientation parameters. To do this, image processing was performed with Pix4D Mapper and the accuracy of the results was analyzed. In order to analyze the variation of the accuracy according to the exterior orientation parameters in detail, the exterior orientation parameters of the first processing result were used as meta-data for the second processing. Subsequently, the amount of change in the exterior orientation parameters was analyzed by in a strip-by-strip manner. As a result, it was proved that the changes of the Omega and Phi values among the rotation elements were related to a decrease in the height accuracy, while changes in Kappa were linked to the horizontal accuracy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.578-588
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• 2019

As the service industry develops, service quality, customer satisfaction, and human resource management are considered priorities in modern management to maintain a company's growth. Therefore, understanding the strategic importance of service marketing is an essential task for modern companies. This study examined the relationship between the internal service quality of employees in the organization and customer orientation through organizational effectiveness. In the case of an airline, a service can be defined as an interaction between an external customer and an internal customer service provider. This interaction significantly affects the behavior and attitude of the employees. Based on the results, empowerment has a significant influence on the internal service quality, but it has no significant effect on customer orientation. As the relationship between department and employees improved, the more confident staff showed an improved ability to perform their work. Therefore, it is important that the organizational structure and the reporting system are as concise and clear as possible to allow employees to accurately recognize the authorities and responsibilities assigned to them and have autonomy and discretion in the framework.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.1
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• pp.1178-1186
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• 2001

This paper presents design and analysis of a 6 degree-of-freedom new haptic device using a par-allel mechanism for interfacing with virtual reality. The mechanism is composed of three pantograph mecha-misms that, driven by ground-fixed servomotors. stand perpendicularly to the base plate. Three spherical joints connect the top of the pantograph with connecting bars, and three revolute joint connect connecting bars with a mobile joystick handle. Forward and inverse kinematic analyses have been performed and the Jacobian matrix is derived by using the screw theroy. Performance indices such as GPI(Global Payload Index), GCI(Global Conditioning index), Traslation and Orientation workspaces, and Sensitivity are evaluated to find optimal pa-rameters in the design stage. The proposed haptic mechanism has better load capability than those of the ex-isting haptic mechanisms due to the fact that motors are fixed at the base. It has also wider orientation work-space mainly due to RRR type spherical joints.

• Journal of Mechanical Science and Technology
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• v.20 no.7
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• pp.1030-1042
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• 2006

An experimental study has been performed to investigate the off-take phenomena at the header-feeder systems (horizontal header pipe with multiple feeder branch pipes) in a CANDU (CANadian Deuterium Uranium) reactor with the branch orientation varies ${\pm}36^{\circ}\;or\;{\pm}72^{\circ}$. In order to evaluate the applicability of the conventional correlations used in the safety analysis code, RELAP5-Mod3, the test facility is designed with the 1/2 scale of the. CANDU 6. It was found that the data set for the top, bottom and side branches are in a good agreement with the correlations used. However, for the specific angled branches, ${\pm}36^{\circ}\;and\;{\pm}72^{\circ}$, the onsets of off-take data and quality data showed large deviation with the conventional model inside RELAP5-MOD3. Furthermore, based on the uncertainty analysis, the conventional 2.5 power law needs to be modified. The present experimental data set can be useful for the construction of the general correlation considering the arbitrary branch orientation.

• Structural Engineering and Mechanics
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• v.71 no.2
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• pp.197-210
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• 2019

Probabilistic buckling behavior of sandwich panel considering random system parameters using a radial basis function (RBF) approach is presented in this paper. The random system properties result in an uncertain response of the sandwich structure. The buckling load of laminated sandwich panel is obtained by employing higher-order-zigzag theory (HOZT) coupled with RBF and probabilistic finite element (FE) model. The in-plane displacement variation of core as well as facesheet is considered to be cubic while transverse displacement is considered to be quadratic within the core and constant in the facesheets. Individual and combined stochasticity in all elemental input parameters (like facesheets thickness, ply-orientation angle, core thickness and properties of material) are considered to know the effect of different degree of stochasticity, ply- orientation angle, boundary conditions, core thickness, number of laminates, and material properties on global response of the structure. In order to achieve the computational efficiency, RBF model is employed as a surrogate to the original finite element model. The stiffness matrix of global response is stored in a single array using skyline technique and simultaneous iteration technique is used to solve the stochastic buckling equations.

• Journal of Digital Convergence
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• v.15 no.4
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• pp.243-250
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• 2017

Since the global financial crisis in 2008, countries around the world have emphasized the activation of entrepreneurship and entrepreneurship as essential strategies for survival. In the case of developed countries, the United States, the European Union and China actively promote entrepreneurship and entrepreneurship. In Korea, on the other hand, the importance of entrepreneurship is emphasized by stagnating growth of companies and strengthening their competitiveness through convergence within companies or companies. The purpose of this study is to investigate the relationship between entrepreneurship and learning orientation in order to enhance competitiveness of Korean companies and to be the basis of management strategy for growth of convergence companies based on this. For the progress of this study, the convergence companies were targeted and the hypothesis was verified through the questionnaire survey through the statistical program. The results of the study showed that Innovation influenced learning orientation. Second, Initiative was found to affect learning orientation. Finally, it is shown that risk sensitivity does not affect learning orientation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5998-6008
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• 2015

The value of social network and entrepreneurial orientation has widely been acknowledged as a critical resource of business success. However, the previous studies did not specify each role and conceptually have examined them as separate antecedents of firm performance. This study develops propositions concerning network capabilities and investigates the moderating effects of network structures (degree centrality, closeness centrality, and betweenness centrality) on the relationship between entrepreneurial orientation and firm performance. This research conducted with a sample of 115 small consulting companies in Korea. The findings indicate that closeness centrality moderates the relationship between proactiveness and performance. Also, the combination of betweenness centrality and proactiveness exerts a positive impact on performance. Accordingly, degree centrality enhances the influence of innovativeness on performance. In particular, betweenness centrality exacerbates the influence of risk-taking on performance against our expectation. Overall, these findings conclude the synergistic effects of network capability and entrepreneurial orientation on firm performance. Finally, practical implications and academic propositions are presented regarding the way firms could most effectively utilize entrepreneurial orientation and network capability to maximize firm performance.

• Korea Trade Review
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• v.43 no.3
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• pp.147-168
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• 2018

Korean foreign direct investment (FDI) firms procure cheap raw materials, produce goods in developing countries featuring low rent and labor costs, and sell goods in world market. In this regard, global supply chain management is important to Korean FDI firms. The objective of this study is to analyze gaps in the performance of reliability and quality of supply chain orientations. To achieve this objective, this study confirms theoretical relationships between variables through prior research, selects measuring variables, and analyzes data collected from Korean FDI firms. Results are as follows; First, there is a gap in reliability performance among the levels of supply chain orientation. Managers should check the level of their supply chain orientation and make strategic and structural efforts to improve reliability performance. Second, there is a gap in quality performance among the levels of supply chain orientation. To improve quality performance, managers should identify the level of their supply chain orientation. In addition, managers can enhance quality performance on the basis of strategic and structural efforts.

• Steel and Composite Structures
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• v.20 no.3
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• pp.693-718
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• 2016

This paper presents a finite element procedure based on Bridging multi-scale method (BMM) in order to incorporate the effect of local/cross-sectional deformations (e.g., flange local buckling and web crippling) on the global behaviour of thin-walled members made of fibre-reinforced polymer composite laminates. This method allows the application of local shell elements in critical regions of an existing beam-type model. Therefore, it obviates the need for using computationally expensive shell elements in the whole domain of the structure, which is otherwise necessary to capture the effect of the localized behaviour. Consequently, highly accurate analysis results can be achieved with this method by using significantly smaller finite element model, compared to the existing methods. The proposed method can be used for composite polymer laminates with arbitrary fibre orientation directions in different layers of the material, and under various loading conditions. Comparison with full shell-type finite element analysis results are made in order to illustrate the efficiency and accuracy of the proposed technique.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.389-397
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• 2011

The global dynamic window approach (DWA) is widely used to generate the shortest path of mobile robots considering obstacles and kinematic constraints. However, the dynamic constraints of robots should be considered to generate the minimum-time path. We propose a modified global DWA considering the dynamic constraints of robots. The reference path is generated using A* algorithm and smoothed by cardinal spline function. The trajectory is then generated to follows the reference path in the minimum time considering the robot dynamics. Finally, the local path is generated using the dynamic window which includes additional terms of speed and orientation. Simulation and experimental results are presented to verify the performance of the proposed method.