• KDI Journal of Economic Policy
• /
• v.29 no.1
• /
• pp.113-136
• /
• 2007

Korean house prices have risen rapidly since year 2001 and there have been some worries that the recent house price hikes are too excessive. This paper empirically analyzes the movement of Korean house prices and derives some implications from it, based on three different theoretical asset pricing models; long-run supply demand model, present value model and general asset pricing model. The results from the analyses show that recent house prices are overall higher than the theoretical prices, thus requiring measures to stabilize house prices hikes.

• Asia pacific journal of information systems
• /
• v.9 no.2
• /
• pp.39-58
• /
• 1999

This paper determines the interactive effects of information technologies(IT) on corporate performances. IT was measured inclusively in terms of technology level, information level, functional level, and management level. Corporate performances were composed of the effectiveness of IT and the financial performance of a corporation. The effectiveness of IT was measured in terms of satisfaction with the support of IT department and with output information, whereas financial performance of corporation was measured in terms of market growth and profitability. Theoretical and empirical analyses lead to the followings. In the theoretical aspect, IT in a corporation needs to be measured broadly. And a study of IT related to corporate performance needs to use either a conversion effectiveness model or an intermediate effect model rather than a direct effect model. In the empirical aspect, the effectiveness of IT within an organization improves with some of the interactive effect of ITs including technology level, information level, functional level, and management level. So do some of the financial performances of a corporation.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.105-109
• /
• 1996

The calculation of the total power required at the Continuous Extrusion Forming(CONFORM) has been performed by the theoretical analysis of three transformation regions(primary grip length and extrusion grip length, flashing). In this study, that was performed by five transformation regions(biting, upsetting, filling, extruding, flashing)and four transformation regions(biting, upsetting and filling, extruding, flashing) and then results of theoretical analyses were compared with experimental results. Results of analysis by four and five transformation regions than that of three transformation regions in the CONFORM showed in a good agreement with experimental results.

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 2008.10b
• /
• pp.537-544
• /
• 2008

The purpose of this study is to find essential delivery service quality elements of internet shopping mall and to investigate the relationship among delivery service quality, satisfaction, trust, and loyalty in the area of internet shopping malls. To do so, theoretical literature review and empirical survey accomplished. The empirical results of this study are summarized as follows. Firstly, accuracy, quickness, safety, information providing, and institutional guarantee have a positive influence on satisfaction. Secondly, accuracy, quickness, information providing, and institutional guarantee have a positive influence on trust. Lastly, satisfaction has a positive influence on trust, and both of satisfaction and trust have a positive influence on loyalty in internet shopping malls. From the analyses of this study, we offer several implications both theoretical and practical perspective.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.13 no.2
• /
• pp.178-178
• /
• 1999

In recent years, the electromagnetic environments are varied with the increase of power consumption and the spread of household electric appliances. Most of the interests to date have concentrated in the area of human health effects associated with exposure to power frequency electric and magnetic fields, and thus the precise measurement and analysis are required. In this paper, the measurements and analysis of the extremely low frequency(ELF) electric and magnetic fields produced by actual 22.9[kV] distribution lines were performed. The experiments have been carried out by lateral profile, and the theoretical analyses were made by use of FIELDS program for the sate of comparison with the experimental data. Electric and magnetic field intensity were strong under power distribution lines, and were inversely proportional to lateral distance. The profiles of electric and magnetic fields were M and ∩ shapes, respectively, and the measured data were good in agreement with the theoretical results. Both the electric and magnetic field intensity were increased with increasing the measurement height.

• Journal of Drive and Control
• /
• v.9 no.4
• /
• pp.42-51
• /
• 2012

Variable displacement vane-type oil pumps represent one of the most innovative pump types for industrial applications, especially for engine lubrication systems. This paper deals with a modeling method for theoretical flow rate investigation of a typical variable displacement vane-type oil pump. This theoretical model is based on the pump geometric design and dynamic analyses. It can be considered as mandatory steps for a deeper understanding of the pump operation as well as for effectively implementing the pump control mechanisms to satisfy the urgent demands of engine lubrication systems. The developed pump model is finally illustrated by numerical simulations.

• 유공압시스템학회:학술대회논문집
• /
• 2010.06a
• /
• pp.25-32
• /
• 2010

A geortor type pump is widely used in lubrication and actuator systems. Especially the pump is an essential machine element of an automotive engine to feed lubrication oil and power source of automatic transmission. A gerotor is a planar mechanism consist of a pair of rotor and circular tooth of stator assembly which forms a closed space. However, related industries do not have necessary technology to design and optimize the pump and paid royalties of gerotor profile on an advanced company. Also, gerotor profiles with setting design parameter have not been sufficiently analyzed from a theoretical view. Therefore, it is very difficult for designer to decide the specifications of the gerotor profiles, and calculation and fluctuation of flow rate is not yet confirmed. In this study, theoretical analyses and optimal design of the gerotor profiles have been performed numerical method by mathematical base. An automated design system of the tooth profile has been developed through MATLAB GUI Program considering various design parameters.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.7 no.2
• /
• pp.36-43
• /
• 2003

The analytic solution of radial displacements of thin cylindrical pressure vessel with carbon fiber T700/Epoxy orthotropic composites was obtained using equilibrium equations of the orthogonal curvilinear coordinate system. The governing equations with the simplified strain versus displacement relation of 3-dimensional curvilinear coordinate system were derived from the variational principle and the virtual work principle. Some theoretical analyses were presented and compared with the results of hydraulic tests for the pressure vessels with some various thicknesses. The results of the theoretical analysis and the hydraulic test were reasonably matched.

• Proceedings of the KSR Conference
• /
• 2005.11a
• /
• pp.152-157
• /
• 2005

Recently, higher speeds have been promoted in old overhead-lines. For high-speed operation in electric railways, increasing contact loss of the pantograph is one of the most important subjects. The contact loss causes power interruption and increases wear of contact strips and contact wires. In order to investigate the causes of contact loss and to work out effective improvement methods, theoretical analyses, experiments have been carried out. First of all, the wave propagating velocity (phase velocity) and characteristics of contact wire are one of the important indices for the current collecting performance. In this paper, mathematical formula arc derived for the prediction of the traveling wave velocity. The measured values in the experiment agree well with the theoretical predictions.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.446-454
• /
• 2003

This paper derived a theoretical method to estimate structural characteristics of carbody members when material substitution designs were performed, and verified the theoretical method with finite element analyses. For important factors in rolling stock design, such as bending stiffness, natural frequency, bending strength and buckling strength, some performance indices to estimate structural behaviors were developed in order to derive an equivalent design in spite of material substitutions. The developed method was used to reduce the weights of carbody components, as example problems, by substituting the aluminium alloy for the structural steel. The analysis results of the examples show that the proposed technique gives a reasonable initial guess in the case of a material substitution design.