• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.717-724
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• 2017

To improve the running safety of a tram operating on a concrete embedded track, a bogie, the core system of the tram, was developed and fabricated. After it was integrated with the prototype car body, a short distance track with a sharp curve and steep gradient was constructed for the test operation. A formula to check the interference of the wheel flange with the track during running was proposed. Based on the results provided by the formula, the track was designed. Another simple formula was derived to estimate the derailment quotient and the wheel unloading ratio. During running on the track, the acceleration of the car body was measured and the interface status between the wheel and the track was monitored by a video system. According to the results calculated by these simple formulas, the derailment quotient and wheel unloading ratio were estimated to be within the safety criteria. In the actual test, no derailment occurred and the measured acceleration satisfied the criteria. Also, there was no interference between the wheel and track. The video monitoring results showed no signs of derailment, such as the climbing of the wheel. The pinion in the center showed good running safety, contacting smoothly with the rack. The measurements of environmental noise proved that the criteria were satisfied.

• Journal of Distribution Science
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• v.14 no.11
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• pp.5-17
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• 2016

Purpose - The purpose of this study is to establish an conceptual framework to explain the mechanism of internationalization behavior being used by recently established retailer in emerging countries. Research design, data, and methodology - The existing research on retail internationalization has focused on global retailers located in advanced countries which have expanded their business to emerging countries. That is, "internationalization from top to bottom". However, recent years have seen a reversal in this trend, resulting in the emergence of "internationalization from bottom to top" by retailers based in emerging economies. In order to explore this reversal, this study attempts to develop an conceptual framework based on the theories of "innovation" and "retail format". Results - This study found an conceptual framework which was adopted both a concept of "formula" derived from the theory of retail format and a concept of "production and process innovation" derived from the theory of innovation as a core concept. Conclusions - The conceptual framework provided an understanding of how retailers in emerging countries have gained a competitive advantage over retail companies based in countries with advanced economies. It suggested that innovation that gave these companies a competitive edge was caused by competitive interaction which allowed them to expand to oversea markets.

• The Journal of Korean Association of Computer Education
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• v.5 no.3
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• pp.27-35
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• 2002

This paper is presented a model of management and application of PC, one of the most important computer resources and software and a model for optimal speed of network to organize information budget of University. I propose strategies to promote utilization degree of existing PCs, problems and strategies to maintain PC, effective strategies to expand PC and change into new models, and strategies to utilize effectively and purchase softwares. Also, I propose an optimal model for network environment and management, which is core to establish master plan of information system. Network is divided into internal and external network and formula model is proposed to calculate optimal speed of these. And strategy is proposed to maintain security of University preserving its characteristics.

• Steel and Composite Structures
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• v.28 no.5
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• pp.573-588
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• 2018

The objective of this paper is to investigate the mechanical performances of polygonal concrete-filled circular steel tubular (CFT) stub columns under axial loading through combined experimental and numerical study. A total of 32 specimens were designed to investigate the effect of the concrete strength and steel ratio on the compressive behavior of polygonal CFT stub columns. The ultimate bearing capacity, ductility and confinement effect were analyzed based on the experimental results and the failure modes were discussed in detail. Besides, ABAQUS was adopted to establish the three dimensional FE model. The composite action between the core concrete and steel tube was further discussed and clarified. It was found that the behavior of CFT stub column changes with the change of the cross-section, and the change is continuous. Finally, based on both experimental and numerical results, a unified formula was developed to estimate the ultimate bearing capacity of polygonal CFT stub columns according to the superposition principle with rational simplification. The predicted results showed satisfactory agreement with both experimental and FE results.

• Journal of the Korean Society of Propulsion Engineers
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• v.7 no.1
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• pp.40-48
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• 2003

Large eddy simulation is used to investigate the compressible flow over a open cavity, The sub-grid scale stresses are modeled using the dynamic model. The compressible Navier-Stokes equations are solved with the sixth order accurate compact finite difference scheme in the space and the 4th order Runge-Kutta scheme in the time. The results show a typical flow pattern of the shear layer mode of oscillation over the cavity. The votical disturbances, the roll-up of vorticity, and impingement and scattering of vorticity at the downstream cavity edge can be seen in the shear layer. Predicted acoustic resonant frequency is in good agreement with that of the empirical formula. The mean flow streamlines are nearly horizontal along the mouth of the cavity. The pressure has its minimum value in the vortex core inside the cavity.

• Steel and Composite Structures
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• v.23 no.2
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• pp.229-238
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• 2017

This paper presents a combined numerical and theoretical study on the composite action between steel and concrete of circular steel tube confined concrete (STCC) stub columns under axial compressive loading with a full theoretical elasto-plastic model and finite element (FE) model in comparison with experimental results. Based on continuum mechanics, the elasto-plastic model for STCC stub columns was established and the analysis was realized by a FORTRAN program and the three dimensional FE model was developed using ABAQUS. The steel ratio of the circular STCC columns were defined in range of 0.5% to 2% to analyze the composite action between steel tube and concrete, and make a further study on the advantages of the circular STCC columns. By comparing the results using the elasto-plastic methods with the parametric analysis result of FE model, the appropriate friction coefficient between the steel tube and core concrete was defined as 0.4 to 0.6. Based on ultimate balance theory, the formula of ultimate load capacity applying to the circular STCC stub columns was developed.

• Journal of the Korean Operations Research and Management Science Society
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• v.37 no.3
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• pp.23-37
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• 2012

As Customer Relationship Management (CRM) strategy is becoming a core competence more recently, many companies want a reliable CRM assessment system which enables measuring and diagnosing corporate customer strategies for building an optimized CRM strategy. However, there has been short of researches on developing the CRM diagnosis methodology that is directly applicable to real practices. Drawing upon the theoretical framework of CRM scorecard, we developed and suggested a corporate CRM diagnosis methodology that can systematically understand and assess the corporate CRM capability and performance, guiding their future directions. Companies can search the important but weak areas among various CRM strategy subjects through the proposed diagnostic procedures. This framework has a hierarchical structure that has four evaluative domains each of which has several evaluative subjects consisting of many evaluative themes: the score of upper factor is the weighted average of its subordinate factor scores. And the score of each evaluative theme is the weighted average of quantitative and qualitative evaluative indexes. Quantitative indexes are calculated by analyzing customer and sales data and qualitative ones are derived from survey data. Each evaluative index has more than one measure and its score can be derived from its own formula consisting of the measures. To prove the concept, we applied this framework to a real company and concluded that it might be appropriate to understand the corporate CRM strategy situation, find the pain points, and resolve them for better CRM implementation.

• Composites Research
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• v.14 no.2
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• pp.43-49
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• 2001

The characteristics of smart skin for wireless LAN system under compression load are investigated. The smart skin structure is composed of 3 layers of face material and 2 layers of core material. Theoretical formula for determining buckling load is derived by Rayleigh-Ritz method and compared with experimental result. The maximum length of specimen that buckling does not occur is determined by assuming that the compression load is sustained by only face material. In the experiment, if buckling occurs obviously then it follows the theoretical result well. In the process of buckling, the load supporting capability and the antenna property such as radiation pattern and reflection coefficient were examined.

• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.72-76
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• 2005

Some mononuclear oxovanadium(IV) complexes having the general formula [VOL(bidentate)] (1-4) of which L is tridentate ONS-donor salicylaldehyde S-methyldithiocarbazate (sal-mdtc$^{2-}$) or salicylaldehyde 4- phenylthiosemicarbazate (sal-phtsc$^{2-}$) and bidentate stands for 2,2'-bipyridyl (bpy) or 1,10-phenanthroline (phen) have been synthesized. The complexes were characterized by elemental analyses, FAB mass, UV, IR spectroscopy, and cyclic voltammetry. Two of the complexes [VO(sal-mdtc)(bpy)] (1) and [VO(sal-mdtc) (phen)] (2) were crystallographically characterized. The structures revealed that vanadium atom is octahedrally coordinated by the O, N, and S donor atoms of the tridentate ligand, the two N atoms of bidentate ligand, and the oxo atom. The oxygen donor, occupying an apical position has a trans-labilizing effect, resulting in elongation of the V-N bond. The cyclic voltammograms of the complexes exhibited one cathodic response in the range −d1.45 $\sim$ −f1.52 V due to the reduction of V(IV) to V(III).

• Spatial Information Research
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• v.21 no.4
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• pp.7-14
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• 2013

Recently, R&D(Research and Development) is processing actively on range search in the road network environments. However, the existing representative range search techniques have shortcomings in that the greater the number of POI's, the more increased storage space or the more increased search time due to inefficient search process. Accordingly, In this paper, we proposed a range search technique using QRMP(QR-tree using Middle Point) to solve the problems of conventional range search techniques. In addition, we made a formula to obtain the total size of the storage space for QRMP and proved the excellence of the range search technique proposed in this paper through the experiment using actual road networks and POI data.