• Journal of Korean Society for Quality Management
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• v.40 no.4
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• pp.453-466
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• 2012

Purpose: The Kano model has been widely accepted as a method for classifying quality attributes for almost three decades since its introduction. However, the wordings of the five alternatives in the Kano's questionnaire has been criticised for unclear and confusable meanings. New wordings of the five alternatives are proposed in this paper. Methods: To evaluate the effectiveness of the proposed wordings, we classify 30 quality attributes of smartphones using the conventional wordings and the proposed wordings respectively. The two classification results are compared with the direct classification results by undergraduate students who learned the Kano model. Results: The classification results using the proposed wordings are much more consistent with the direct classification results than those using the conventional wordings. Conclusion: The proposed wordings are less confusable and easy to understand, and thus it results in more consistent with the direct classification.

• Journal of Mechanical Science and Technology
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• v.18 no.11
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• pp.2032-2041
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• 2004

Results from an experimental study of flow distribution in a close-coupled catalytic converter(CCC) are presented. The experiments were carried out with a flow measurement system specially designed for this study under steady and transient flow conditions. A pitot tube was a tool for measuring flow distribution at the exit of the first monolith. The flow distribution of the CCC was also measured by LDV system and flow visualization. Results from numerical analysis are also presented. Experimental results showed that the flow uniformity index decreases as flow Reynolds number increases. In steady flow conditions, the flow through each exhaust pipe made some flow concentrations on a specific region of the CCC inlet. The transient test results showed that the flow through each exhaust pipe in the engine firing order, interacted with each other to ensure that the flow distribution was uniform. The results of numerical analysis were qualitatively accepted with experimental results. They supported and helped explain the flow in the entry region of CCC.

• Journal of Astronomy and Space Sciences
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• v.12 no.2
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• pp.157-167
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• 1995

OH/IR stars are the most massive and youngest subclass in asymptotic giant branch stars which pass through sporadic superwind phases. We have modeled the dust envelopes around OH/IR stars with close attention to the evolution of the structure of the dust shells. We use various dust density distributions to take account the effect of the superwind due to the helium shell flash by adding a density increased region. Depending on the position and quality of the density increased region, the model results are different from the results with conventional density distribution. The new results fit the observations of some OH/IR stars better. Especially, the OH/IR stars with excessive 30-100$\mu$m emission can be better explained by the new results. The IR two-color diagrams comparing the results of the superwind models and IRAS observation of 95 OH/IR stars have been made. The new results can explain much wider regions on the IR two-color diagrams.

• Structural Engineering and Mechanics
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• v.61 no.2
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• pp.221-230
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• 2017

In this paper, we investigated the propagation of thermoelastic surface waves in fibre-reinforced anisotropic general viscoelastic media of higher order of nth order including time rate of strain under the influence of rotation. The general surface wave speed is derived to study the effectsof rotation andthermal onsurface waves. Particular cases for Stoneley, Love and Rayleighwaves are discussed.The results obtained in this investigation are more general in the sense that some earlier published results are obtained from our result as special cases. Our results for viscoelastic of order zero are well agreed to fibre-reinforced materials. Comparison was made with the results obtained in the presence and absence of rotation and parameters for fibre-reinforced of the material medium. It is also observed that, surface waves cannot propagate in a fast rotating medium.Numerical results for particular materials are given and illustrated graphically. The results indicate that the effect of rotation on fibre-reinforced anisotropic general viscoelastic media are very pronounced.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.10
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• pp.3152-3159
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• 1996

Previous works about the cylindrical shape elastic body which is under longitudinal temperature distribution mostly show the results of free expansion, therefore exact thermo-elastic analysis is needed. The object of this work is to analyze the thermo-elastic problem of the hollow cylinder when the cylinder is under longitudinal temperature distribution. In this paper, the analytical solution is found by using Galerkin vector, and it is compared by the results of FEM. For displacements of cylinder, analytical values are almost same as the results of FEM, but free expansion is not fit for analytical solution and the results of FEM. stresses from analytical solution and the results of FEM show good agreement also. but the results are different near the end boundary, since St. Venant principle is applied.

• 한국연소학회:학술대회논문집
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• 2002.11a
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• pp.173-184
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• 2002

In order to evaluate the devolatilization models of pulverized coal, various devolatilization models are examined for the numerical analysis of Drop Tube Furnace.The results of analysis are compared with the experimental results. A numerical study was conducted to explore the sensitivities of the predictions to variation of the model parameters. It helps to elucidate the source of the discrepancies. Three different wall temperature conditions of the DTF, 1100, 1300 and $1500^{\circ}C$ were considered in this analysis. Two fuels are U.S.A. Alaska coal and Australia Drayton coal. The results of analysis with constant rate model, single kinetic rate model and two competing rate modes well presented fast volatile matter release in the early devolatilization. However, in the latter devolatilization they did not coincide with experimental results which presented tardy volatile matter release on account of pyrolysis of high molecular substance. On the other hand, the results of analysis with DAEM(Distribute Activation Energy Model) coincided with experiment al results in overall devolatilization.

• Structural Engineering and Mechanics
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• v.39 no.4
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• pp.449-463
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• 2011

A free vibration analysis is made of a moderately-thick toroidal shell based on a shear deformation (Timoshenko-Mindlin) shell theory. This work represents an extension of earlier work by the authors which was based on a thin (Kirchoff-Love) shell theory. The analysis uses a modal approach in the circumferential direction, and numerical results are found using the differential quadrature method (DQM). The analysis is first developed for a shell of revolution of arbitrary meridian, and then specialized to a complete circular toroidal shell. A second analysis, based on the three-dimensional theory of elasticity, is presented to cover thick shells. The shear deformation theory is validated by comparing calculated results with previously published results for fifteen cases, found using thin shell theory, moderately-thick shell theory, and the theory of elasticity. Consistent agreement is observed in the comparison of different results. New frequency results are then given for moderately-thick and thick toroidal shells, considered to be completely free. The results indicate the usefulness of the shear deformation theory in determining natural frequencies for toroidal shells.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05b
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• pp.17-20
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• 2010

Recent Construction and Transportation R&D projects are larger in size, investment scale has been increasing rapidly. However, the results of Construction and Transportation in R & D are papers, patents and other results. So, the application record of R&D in the construction field is very lacking. In particular, Construction New Technology's ratio in the midst of R&D's results are about 2.29%. Therefore, this study suggested program that R&D's results has been connected Construction New Technology. The introduction of the new system has greatly increased Construction New Technology and the results of excellent &D will be applied in construction field. So, Cost-reduction and technology's improvement are expected.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.2
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• pp.170-180
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• 2000

The equation which is related to TXV performance was investigated. On the basis of this equation, the TXV simulation program was developed. Results of the developed TXV simulation program were proven by the experiment on the influence of pressure difference between TXV entrance and exit and equalizing pressure. Simulation results show very good agreement with experimental results, the RMS error between them was 1.83%. The capillary tube simulation program was made by the basic equation of fluid dynamics. Results of this program were proven by data which were experimented previously. The RMS error between simulation results and experimental results was 4.13% .

• IE interfaces
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• v.20 no.2
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• pp.133-141
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• 2007

As the sales of the Sports Toto, the Korean lottery on sports games, have increased significantly in recent five years, interest in predicting the various results of sports matches has also been raised. Dixon and Coles (1997) proposed a bivariate Poisson model to predict the results of English soccer league matches. In this paper, we pay attention to the physical condition of players that may affect soccer match results and revise Dixon and Coles' model to consider probable fatigue due to the players' short rest followed by their frequent matches. We observed the fatigue effect in the match results, and found positive betting returns available when using our prediction model. Furthermore, the validity of probability-based odds in European and Korean betting markets is analyzed.