• Laser Solutions
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• v.9 no.1
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• pp.25-29
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• 2006

This study aimed to investigate the change of mechanical properties with the rolling direction and shielding condition during laser welding of AZ31 magnesium alloy. AZ31 magnesium alloy sheets of 1mm thickness were welded using a continuous wave Nd:YAG laser with and without Ar shielding gas. The effect of Ar shielding gas and rolling direction on the mechanical properties were investigated using Vickers hardness, transverse-weld tensile. Porosity in the weld metals was investigated using an optical microscope. The experimental results showed that mechanical properties of AZ31 magnesium alloy laser welds were upgraded compared to those of base metal. Mechanical properties of AZ31 magnesium alloy laser welds were not substantially changed when Ar shielding gas was supplied.

• Journal of Digital Convergence
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• v.5 no.1
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• pp.101-116
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• 2007

The purpose of this paper is to suggest field-oriented policy of regional innovation support system. To accomplish this purpose, we examined the status quo of technical support, performance satisfaction of consumers and practical issues. The key factors influencing core technical innovation of small and medium firms are development fund, R&D employees, experimental instrument, technical information, protection of intellectual property, subcontracting and so on. To make sure of practical effect, therefore, it would rather necessary to implement policy support linking government and supporting means on the ground of needs of small and medium firms than specific method such as funding.

• International Journal of CAD/CAM
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• v.1 no.1
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• pp.23-32
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• 2002

In this paper, a new technique of space deformation for parametric surfaces with so-called extension function (EF) is presented. Firstly, a special extension function is introduced. Then an operator matrix is constructed on the basis of EF. Finally the deformation of a surface is achieved through multiplying the equation of the surface by an operator matrix or adding the multiplication of some vector and the operator matrix to the equation. Interactively modifying control parameters, ideal deformation effect can be got. The implementation shows that the method is simple, intuitive and easy to control. It can be used in such fields as geometric modeling and computer animation.

• Journal of Korea Game Society
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• v.3 no.2
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• pp.3-11
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• 2003

Game software planning is divided into initial game software planning and detailed game software planning. Technique, design, marketing should be considered in initial game software planning. Especially, technical considerations, platform and game engine and sewer construction and sewer architecture should have effect on development cost and time. So, game software designer should choose technical consideration which is suitable for purpose of game software planning. In this paper, we researched technical considerations in initial game software planning, focusing on platform, game engine, game service, network infrastructure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.238-239
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• 2005

With the aim of developing XLPE insulation for extra high voltage cable, we investigated the morphology of cross-linked polyethylene. We used a kind of base materials and additives, and controlled curing condition and amount of additives. The effect of addition of additives on morphology of XLPE such as lamellar density, orientation and additive layer were analyzed using TEM analysis. We applied this result to diffused additive amount was analyzed using FT-IR analysis, and the change of microstructure as the degree of additive diffusion was analyzed using TEM analysis.

• Korea Trade Review
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• v.43 no.3
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• pp.1-26
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• 2018

This study estimates the technical efficiency and total factor productivity(TFP) of and analyzes the relationship between TFP and exports for Korean manufacturing companies from 2000 to 2016. Specially, TFP is decomposed into Technical Change(TC), Technical Efficiency Change (TEC), and Sale Effect(SE), and compared between large and small enterprises. First, in the case of technical efficiency, the Korean economy has been very vulnerable to external shocks, such as the sharp decline following the 2008 financial crisis. The efficiency of the electronics, automobile, and machinery sectors is low and needs to be improved. In addition, the technological efficiency of large enterprises is higher than that of SMEs in most manufacturing sub-sectors except for non-ferrous metals. In the case of TFP, most changes are due to TC, and the effective combination of labor, capital and the effect of scale have little effect, suggesting that improvement of internal structure is urgent. In addition, volatility due to the impact of the financial crisis in 2008 was much larger in SMEs than in large companies, so external economic impacts are more greater for SMEs than large enterprises. The relationship between TFP decomposition factors and exports shows that TC has a positive effect only on exports of SMEs. Therefore, in order to increase exports, in the case of SMEs, R&D support to promote technological development is needed. In the case of large companies, it is necessary to establish differentiated strategies for each export market, competitor company, and item to link efficiency and scale effect of exports.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.19 no.2
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• pp.141-157
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• 2024

This study analyzes the effect of enterepreneurial competencies on start-up performance through network activities for young entrepreneurs. Enterepreneurial competencies are composed of opportunity recognition competencies, marketing competencies, technical competencies, and creative competencies. A total of 354 questionnaires collected from young entrepreneurs residing in the country were used for empirical analysis. SPSS v28.0 and PROCESS macro v4.3 were analyzed based on the research model of a single-parameter single-mediated model. As a result of the analysis, first, it was found that among the enterepreneurial competencies, opportunity recognition competencies, marketing competencies, technical competencies, and creative competencies have a positive (+) significant effect on network activities. Among them, it was found that marketing competence has the greatest effect on network activities and technical competence has the least effect. Second, network activities were found to have a significant effect on start-up performance in a positive (+) direction. Third, among enterepreneurial competencies, opportunity recognition competence, marketing competence, technical competence, and creative competence were found to have a positive (+) effect on start-up performance. Among them, it was found that creative competence had the greatest effect and technical competence had the smallest effect. Fourth, network activities were found to mediate between enterepreneurial competencies and start-up performance. As for the relative effect size of the indirect effects of independent variables, it was found that marketing competence had the greatest effect on start-up performance and technology competence had the smallest effect. The academic implications of this study include investigating the significance and relationship of various variables, providing verification of theoretical frameworks related to entrepreneurship, identifying the main drivers of start-up success, and suggesting the importance of the network between enterepreneurial competencies and start-up performance. In addition, the practical implications of this study suggest the importance of marketing competencies for networking, and suggest differentiation of competencies. It emphasizes the strategic role of creative competence and provides guidance to policymakers for supporting start-ups on customized policies for fostering valuable start-ups.

• Steel and Composite Structures
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• v.17 no.4
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• pp.405-429
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• 2014

In this paper, it is aimed to determine the structural behavior of suspension bridges considering construction stages and different soil conditions. Bosporus Suspension Bridge connecting the Europe and Asia in Istanbul is selected as an example. Finite element model of the bridge is constituted using SAP2000 program considering existing drawings. Geometric nonlinearities are taken into consideration in the analysis using P-Delta large displacement criterion. The time dependent material strength of steel and concrete and geometric variations is included in the analysis. Time dependent material properties are considered as compressive strength, aging, shrinkage and creep for concrete, and relaxation for steel. To emphases the soil condition effect on the structural behavior of suspension bridges, each of hard, medium and soft soils are considered in the analysis. The structural behavior of the bridge at different construction stages and different soil conditions has been examined. Two different finite element analyses with and without construction stages are carried out and results are compared with each other. At the end of the analyses, variation of the displacement and internal forces such as bending moment, axial forces and shear forces for bridge deck and towers are given in detail. Also, displacement and stresses for bridge foundation are given with detail. It can be seen from the analyses that there are some differences between both analyses (with and without construction stages) and the results obtained from the construction stages are bigger. It can be stated that the analysis without construction stages cannot give the reliable solutions. In addition, soil condition have effect on the structural behavior of the bridge. So, it is thought that construction stage analysis using time dependent material properties, geometric nonlinearity and soil conditions effects should be considered in order to obtain more realistic structural behavior of suspension bridges.

• Journal of Digital Convergence
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• v.9 no.6
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• pp.295-311
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• 2011

The government is working out the development of a venture enterprise through a venture certification system. The broad effects of its policies are anticipated by the government and revealed in the 'The Survey on Actual Condition of Venture Enterprises 2010'. These benefits include the revitalization of start-up, promotion of technological innovation, progress in marketing ability, improvement in corporate image, financing and investment, and benefit from tax reduction & exemption. However, with the estimation of production function and sales function, which both uses capital and labor as a basic elements, it was found that only 'financing and ease of investment' produces a statistically significant effect on production and sales. An addition, this study looks into whether venture-supporting system are helpful to the eradication of technical inefficiency. The policies brought about positive changes in reduction of technical inefficiencies except with regard to the ease of start-up where it was found that an increase in inefficiencies was the result.

• Structural Engineering and Mechanics
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• v.67 no.6
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• pp.579-585
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• 2018

Masonry walls are of a complex (anisotropic) structure in terms of their mechanical properties. The mechanical properties of the walls are affected by the properties of the materials used in wall construction, joint thickness and the type of masonry bond. The carried-out studies, particularly in the seismic zones, have revealed that the most of the conventional masonry walls were constructed without considering any engineering approach. Along with that, large-scale damages were detected on such structural elements after major earthquake(s), and such damages were commonly occurred at the brick-joint interfaces. The aim of this study was to investigate the effect of joint thickness and also type of mortar on the mechanical behavior of the masonry walls. For this aim, the brick masonry walls were constructed through examination of both the literature and the conventional masonry walls. In the construction process, a single-type of brick was combined with two different types of mortar: cement mortar and hydraulic lime mortar. Three different joint thicknesses were used for each mortar type; thus, a total of six masonry walls were constructed in the laboratory. The mechanical properties of brick and mortars, and also of the constructed walls were determined. As a conclusion, it can be stated that the failure mechanism of the brick masonry walls differed due to the mechanical properties of the mortars. The use of bed joint thickness not less than 20 mm is recommended in construction of conventional masonry walls in order to maintain the act of brick in conjunction with mortar under load.