• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1603-1608
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• 2012

This paper aims to build a model of unemployment duration, in which each type of unemployment duration can be defined as a function of other exogenous variables. Recently, the so-called mismatch in the labor market has become a big issue in most countries. It is very obvious that 'mismatch' is deeply related to the long duration of unemployment status. Two problems may be head and tail of the same coin. Employing a simple analysis of Markov stochastic process, the model of unemployment duration developed here is useful for seeing the effects of shocks on unemployment duration. The model allows us to distinguish the determinants of different kinds of unemployment and to identify the nature of unemployment duration.

• Asia pacific journal of information systems
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• v.16 no.4
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• pp.121-149
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• 2006

This study tries to explain how the relationship-specificity of invested assets affects E-collaboration and consequently on performance of Small and Medium Enterprises (SMEs). We classify the relationship-specificity of invested assets into four types such as business process specificity, physical asset specificity, domain knowledge specificity, and site specificity. We define E-collaboration as composed of Electronic Information Sharing (EIS) and Electronic Cooperation (E-Co). In addition, we articulate firm's performance as operational and strategic one, and investigate the impacts of EIS and E-Co on its performance. The data were collected from 187 SMEs and used for analysis. Based on the survey results, we find the following: (1) EIS is directly influenced by business process specificity and physical asset specificity, (2) E-Co is affected by site specificity and domain knowledge specificity, (3) EIS has a positive and significant impact on E-Co, (4) EIS affects firm's operational performance, (5) E-Co influences on firm's strategic performance. In conclusions, the higher the level of EIS, SMEs seem to get greater operational performance, Respectively, the higher the level of E-Co, they tend to get greater strategic performance.

• Geomechanics and Engineering
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• v.5 no.3
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• pp.241-261
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• 2013

The bearing mechanism of pile during installation and loading process which controls the deformation and distribution of strain and stress in the soil surrounding pile tip is complex and full of much uncertainty. It is pointed out that particle crushing occurs in significant stress concentrated region such as the area surrounding pile tip. The solution to this problem requires the understanding and modeling of the mechanical behavior of granular soil under high pressures. This study aims to investigate the sand behavior around pile tip considering the characteristics of sand crushing. The numerical analysis of model pile loading test under different surcharge pressure with constitutive model for sand crushing is presented. This constitutive model is capable of predicting the dilatancy of soil from negative to positive under low confining pressure and only negative dilatancy under high confining pressure. The predicted relationships between the normalized bearing stress and normalized displacement are agreeable with the experimental results during the entire loading process. It is estimated from numerical results that the vertical stress beneath pile tip is up to 20 MPa which is large enough to cause sand to be crushed. The predicted distribution area of volumetric strain represents that the distributed area shaped wedge for volumetric contraction is beneath pile tip and distributed area for volumetric expansion is near the pile shaft. It is demonstrated that the finite element formulation incorporating a constitutive model for sand with crushing is capable of producing reasonable results for the pile loading problem.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.1
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• pp.83-86
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• 2005

This study is predicted tool deformation by cutting forces and chip-tool interface temperature in machining process. Modeling of tool is made using 3D CAD software, finite element method is performed by cutting forces and temperature. Cutting forces and temperature used load conditions are predicted using the cutting force model based on machining theory. Experimental milling tests have been conducted to verify the cutting force model. Finally, this study is predicted cutting force components and temperature using cutting conditions, material property, tool geometry without experiment and tool deformation is predicted by cutting forces and temperature in machining process.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.3
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• pp.223-230
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• 2005

Lately, massive concrete structures are increasingly built. Mass concrete structures are cast in many stages with construction joints. Individually constructed segment exhibit different heat source properpies and time dependent properties. As such construction stages must be incorporated in a heat of hydration analysis model to truly reflect a real construction process. Thermal stress analysis is conducted to find the way of controlling the thermal crack of pier footing mat in this paper. The footing mat model fur the analysis is $12m\times14m$ area and 3m height. This study show the process of construction stage and analyzes the results for a foundation structure constructed in 2 stage pours.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.2
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• pp.110-115
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• 2005

Plasma Transferred Arc Spray process was used to make modified surface for wear and corrosion resistant by using Co system powder type alloy. The modified surface was produced by changing only spray current and other process variables were constant. The current range was from 80 amp to 140 amp as inclosing 20 amp. It was appeared that the geometrical shape, microstructures and microhardness of the modified surface were affected by the different cooling rate of base metal. The modified surface that produced by 120 amp current exhibited the fine microstructure and the highest microhardness number impling good surface characteristics. It was also found that the spray current affected the width but not the height of the bead as increasing current.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.3
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• pp.654-659
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• 2007

This study suggests a measure method for measuring variables that are used for hotel corporations' CRM performance. For this purpose, I present a combined method between factor analysis and AHP(Analytic Hierarchy Process) analysis. Factor analysis gives us a result that shows a group of highly correlated variables and another group of less correlated variables. Thus, factor analysis can only give information of factor categorization. Although researchers add ANOVA analysis or regression analysis, these efforts can not connect its results with factor analysis. Therefore, In hotel CRM performance analysis, calculation of each factor's importance is strongly required. For that reason, I suggest a method that combines AHP analysis with factor analysis for Hotel CRM performance measurement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.8-13
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• 2012

Ti-3Al-2.5V ingot was produced, processed into a titanium alloy wire of 9mm diameter, and the characteristics were studied in comparison with imported material. The ingot satisfied ASTM Grade 9 standard showing oxygen content of 0.11wt% and iron content of 0.085wt%. The hardness of the 9mm diameter titanium alloy was similar to that of the imported material showing values between 225 and 250Hv, and the tensile strength of the imported material was 804MPa while that of the domestic development was 734MPa. The elongation of the imported material was 12% while that of the domestic development was 22%. A new process of manufacturing 9.0mm diameter titanium alloy wire through forging and multi-step hot rolling process out of 400mm diameter ingot was developed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.13-20
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• 2010

The development of the console for exterior advertizing LCD Panel(LCD Console) is the purpose of this study with regard to importance of display industry. In this study, the most important point is to develop the cooling system for LCD Console. It is developed by using systematic application techniques and statistical tests and analysis to integrate commercial components, cooling fan, heat sink, thermo electronic modules etc, of it. This study, at first, shows design/manufacturing process of the cooling system and the setting process of control factors to control through experimentation. Next, after constructing the complete console, 46 inch LCD Panel and the cooling system are built in, the performance test of it is shown through experimentation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.1-6
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• 2010

This study presents the preform injection molding and the blow molding of the injection stretch-blow molding process for PET bottles. The numerical analysis of the injection molding and the blow molding of a preform is considered in this paper using CAE with a view to minimize the warpage and the thickness. In order to determine the design parameters and processing conditions in injection/blow molding, it is very important to establish the numerical model with physical phenomenon. In this study, a three dimensional model has been introduced for the purpose and flow simulations of filling, post-filling and cooling process are carried out. The simulations resulted in the warpage in good agreement with the measurements. Also, from the result of numerical analysis, we appropriately predicted the warpage, deformation and thickness distribution along the product walls.