• Proceedings of the KWS Conference
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• 2002.10a
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• pp.752-756
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• 2002

Variable weld bead penetrations related to the base metal chemistry of stainless steels in GTA welding have been under constant investigations due to their industrial implications. It has been proposed that among other elements, the sulfur content of steels determines the weld pool geometry, particularly its penetration. It is suggested that the surface tension temperature gradient of steels becomes positive with appropriate dosing in sulfur and results in inward melt flow, propitious for deeper welds. However, the chemistry of industrial steels is complex due to the presence of multiple minor elements either deliberately added or remnant impurity traces. With this in view, investigations on 41 austenitic and nine martensitic stainless steels were carried to see if there existed any possible relation between the weld profile and some of the designated elements. The results suggest no direct correlation between sulfur or any other major or trace element and weld penetration. At first glance the results are contradictory to what is often asserted.

• Structural Engineering and Mechanics
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• v.47 no.6
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• pp.857-879
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• 2013

Numerical damage assessment of Van train station building consisting of three RC blocks due to 2011 Van Earthquakes by nonlinear dynamic analysis is presented. The structural model is created with rigid-end offsets and plastic hinges for nonlinear analysis. Rigid-end offsets are considered for connection areas and proposed for wall-supported elements. In wall-supported elements, walls take place in a limited part of the columns. Nonlinear dynamic analysis of the building with and without rigid-end offsets is performed by using real earthquake records and results are compared. The results show that rigid-end offsets have significant effects on the seismic behavior of the structures.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1050-1051
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• 2006

• Journal of Digital Convergence
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• v.20 no.2
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• pp.407-413
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• 2022

This study conducted empirical analysis through user experience and questionnaire to find out whether the technical and contextual elements of the 'COVID-19 SABER' VR game produced and developed through initial research affect the improvement of the user's visual immersion. As a result first, the hypotheses regarding the resolution, viewing angle, effect, and design quality of the technical elements were accepted, but the hypotheses regarding the frame rate and the brightness of the lighting were rejected. Next, as for the hypothesis of the contextual elements, the hypothesis about background, directing, color and texture, interest and fun was adopted, and the hypothesis about storytelling was rejected. In summary, it was concluded that in order to increase the visual immersion of VR games, technical elements resolution, viewing angle, effect, design quality, contextual elements background, directing, color and texture, interest and fun must be designed and produced. The results of this study are expected to serve as basic data for the production and development of VR games that can induce and improve user's visual immersion in the future.

• Computers and Concrete
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• v.4 no.2
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• pp.83-100
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• 2007

Applying a direct formulation for the enrichment of the displacement field an extended finite element (XFEM) scheme for modeling of cohesive crack growth is developed. Only elements cut by the crack is enriched and the scheme fits within the framework of standard FEM code. The scheme is implemented for the 3-node constant strain triangle (CST) and the 6-node linear strain triangle (LST). Modeling of standard concrete test cases such as fracture in the notched three point beam bending test (TPBT) and in the four point shear beam test (FPSB) illustrates the performance. The XFEM results show good agreement with results obtained by applying standard interface elements in FEM and with experimental results. In conjunction with criteria for crack growth local versus nonlocal computation of the crack growth direction is discussed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.1
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• pp.20-30
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• 2022

In this study, in order to confirm the relationship between technical innovation competence and corporate performance, the effect of technical innovation competence of small and medium-sized manufacturing companies on corporate performance was identified, and entrepreneurship, which plays a role as a driving force in triggering technical innovation competence, was analyzed to determine whether there is a mediating effect between them. To conduct the research, first, the research model was established by examining previous studies on technical innovation competence, entrepreneurship, and corporate performance. Second, an on-line and offline survey was conducted for employees in companies after constructing a questionnaire that can verify the hypothesis suitable for the research model. Third, the hypothesis was verified by performing validity and reliability analysis, correlation analysis, and regression analysis using a statistical program. Results of this study, first, it was found that R&D competence and technology innovation system, which are elements of technical innovation competence, had a significant effect on financial performance, and technology innovation system and technology accumulation capacity, had a significant effect on non-financial performance. Second, it was analyzed that entrepreneurship has a mediating effect in both R&D capability, technological innovation system and technology accumulation capability, which are elements of technical innovation capability, and financial and non-financial performance, elements of corporate performance.

• Journal of information and communication convergence engineering
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• v.11 no.2
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• pp.103-111
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• 2013

Given the lack of suitable quality evaluation standards for educational serious games (designed for both entertainment and instruction), we designed a development framework for evaluation standards of educational serious games and proceeded to develop standards in accordance with our proposed procedure. Our standards were designed to evaluate the quality of both technical and non-technical elements of educational serious game software products. We conducted a survey on the need for individual elements of the standard. Participants rated the need for each element on a five-point Likert scale. We then performed a reliability analysis of the survey results. Based on the survey results, we established a final standard for quality evaluation composed of 9 main elements and 31 sub-elements. The results of our research will contribute useful information to users as well as to the developers of educational serious games.

• Structural Engineering and Mechanics
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• v.53 no.2
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• pp.189-204
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• 2015

After the large destruction of Lisbon due to the 1755 earthquake, the city had to be almost completely rebuilt. In this context, an innovative structural solution was implemented in new buildings, comprising internal timber framed walls which, together with the floors timber elements, constituted a 3-D framing system, known as "cage", providing resistance and deformation capacity for seismic loading. The internal timber framed masonry walls, in elevated floors, are constituted by a timber frame with vertical and horizontal elements, braced with diagonal elements, known as Saint Andrew's crosses, with masonry infill. This paper describes an experimental campaign to assess the in-plane cyclic behaviour of those so called "frontal" walls. A total series of 4 tests were conducted in 4 real size walls. Two models consist of the simple timber frames without masonry infill, and the other two specimens have identical timber frames but present masonry infill. Experimental characterization of the in-plane behaviour was carried out by static cyclic shear testing with controlled displacements. The loading protocol used was the CUREE for ordinary ground motions. The hysteretic behaviour main parameters of such walls subjected to cyclic loading were computed namely the initial stiffness, ductility and energy dissipation capacity.

• Journal of Welding and Joining
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• v.24 no.4
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• pp.39-49
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• 2006

The austenite grain growth model in low alloyed steel HAZ without precipitates was proposed by analyzing isothermal grain growth behavior. Steels used in this study were designed to investigate the effect of alloying elements. Meanwhile, a systematic procedure was proposed to prevent inappropriate neglect of initial grain size (D0) and misreading both time exponent and activation energy for isothermal grain growth. It was found that the time exponent was almost constant, irrespectively of temperature and alloying elements, and activation energy increased with the addition of alloying elements. From quantification of the effect of alloying elements on the activation energy, an isothermal grain growth model was presented. Finally, combining with the additivity rule, the austenite grain size in the CGHAZ was predicted.

• Computers and Concrete
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• v.5 no.4
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• pp.401-416
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• 2008

The paper presents a methodology to model three-dimensional reinforced concrete members by means of embedded discontinuity elements based on the Continuum Strong Discontinuous Approach (CSDA). Mixture theory concepts are used to model reinforced concrete as a 3D composite material constituted of concrete with long fibers (rebars) bundles oriented in different directions embedded in it. The effects of the rebars are modeled by phenomenological constitutive models devised to reproduce the axial non-linear behavior, as well as the bond-slip and dowel action. The paper presents the constitutive models assumed for the components and the compatibility conditions chosen to constitute the composite. Numerical analyses of existing experimental reinforced concrete members are presented, illustrating the applicability of the proposed methodology.