• Journal of the Korean Applied Science and Technology
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• v.39 no.2
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• pp.233-245
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• 2022

The purpose of this study is to investigate the psychological well-being of Pilates class participants and their intention to continue exercising by examining the passion for leisure of Pilates participants who continue to exercise while taking risks during COVID-19 pandemic. The subjects were 285 Pilates participants. For data processing, SPSS 21.0 and AMOS 18.0 were used, and frequency analysis, reliability analysis, confirmatory factor analysis, and correlation analysis were conducted. In addition, path analysis was SEM and the bootstrapping method was used to examine the mediating effect of psychological well-being in the relationship between the passion for leisure and intention to continue exercising. First, passionate behavior had a positive effect on psychological well-being. Second, passionate behavior had a positive effect on exercise continuity. Third, psychological well-being had a positive effect on exercise continuity. Fourth, psychological well-being played a partial mediating role in the relationship between passionate behavior and exercise continuity.

• Journal of Mechanical Science and Technology
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• v.17 no.1
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• pp.146-156
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• 2003

A numerical algorithm is developed to analyze the performance of a Unit-injector (UI) System for a diesel engine. The fundamental theory of the algorithm is based on the continuity equation of fluid dynamics. The loss factors that should be seriously regarded on the continuity equation are the compressibility effect of liquid fuel, the wall friction loss in high-pressure fuel lines of the system, the kinetic energy loss of fuel in the system, and the leakage of fuel out of the control volume. For an evaluation of the developed simulation algorithm, the calculation results are compared with the experimental outputs provided by the Technical Research Center of Doowon Precision Industry Co. (DPICO) ； the maximum pressure in the plunger chamber (P$\_$p/) and total amount of fuel injected into a cylinder per cycle (Q$\_$f/) at each operational condition. The result shows that the average error rate (%) of P$\_$p/ and Q$\_$f/ are 2.90% and 4.87%, respectively, in the specified operational conditions. Hence, it can be concluded that the analytical simulation algorithm developed in this study can be reasonably applied to the performance prediction of newly designed UI system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1040-1046
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• 2006

This paper is aimed to investigate the deformation caused by ununiform contraction of injection molding with highly big differences of thickness by the continuity of various curvature radius. By CAE analysis, the uniform cooling structure and optimum molding conditions are found for Jars made of SAN and PMMA materials and applied to the design of chill. In order toevaluate the molding pressure, resin temperature, molding temperature, cooling conditions, Moldflow program is applied. As results of experiments, the deformation and inferiority phenomena in Jars are analyzed for each factor and proposed the injection molding conditions to minimize the cooling structure and reduce the cycle time.

• Journal of The Korean Astronomical Society
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• v.38 no.2
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• pp.59-66
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• 2005

A new ion transport code for planetary ionospheric studies has been developed with consideration of velocity differences among ion species involving ion-ion collision. Most of previous planetary ionosphere models assumed that ions diffuse through non-moving ion and neutral background in order to consolidate continuity and momentum equations for ions into a simple set of diffusion equations. The simplification may result in unreliable density profiles of ions at high altitudes where ion velocities are fast and their velocity differences are significant enough to cause inaccuracy when computing ion-ion collision. A new code solves explicitly one-dimensional continuity and momentum equations for ion densities and velocities by utilizing divided Jacobian matrices in matrix inversion necessary to the Newton iteration procedure. The code has been applied to Martian nightside ionosphere models, as an example computation. The computed density profiles of $O^+,\;OH^+$, and $HCO^+$ differ by more than a factor of 2 at altitudes higher than 200 km from a simple diffusion model, whereas the density profile of the dominant ion, $O_2^+$, changes little. Especially, the density profile of $HCO^+$ is reduced by a factor of about 10 and its peak altitude is lowered by about 40 km relative to a simple diffusion model in which $HCO^+$ ions are assumed to diffuse through non-moving ion background, $O_2^+$. The computed effects of the new code on the Martian nightside models are explained readily in terms of ion velocities that were solved together with ion densities, which were not available from diffusion models. The new code should thus be expected as a significantly improved tool for planetary ionosphere modelling.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.409-410
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• 2007

In this paper, we propose a new method for overlap and add synthesis using phase shaping factor in a sinusoidal synthesis method of speech signal, which improves continuity and SNR(Signal Noise Ratio) efficiency of synthesized speech.

• Journal of Ocean Engineering and Technology
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• v.26 no.5
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• pp.55-62
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• 2012

In this paper, the rigid lid boundary condition is applied to simulate the influence of floating structures such as ships or pontoons, and the pressure term in both the momentum equations and continuity equation are modified. The pressure of a floating structure under the free surface is dependent on the draft of the structure, generally called a ship. If the free surface is covered by a floating structure, the free surface cannot move freely. The water level should be fixed, using a rigid lid boundary condition. This boundary condition is implemented by reducing the storage area of the grid cell with a factor between zero and one. The numerical model developed by Hong (2009) is verified through a comparison with experimental results, and the influence of the reduction factor is investigated using the verified numerical model.

• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.258-270
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• 2015

The study aims at verifying the effect of the image, trust and responsiveness to social welfare organizations on continuing the sponsorship of private donors, the mediating effect of the organizational identification and the moderating effect of their financial status. As a result of causal analysis of the variables by structural equation models, regardless of donors' financial status, social welfare organizations' image, trust and responsiveness has no direct effect on continuing the sponsorship. Among the donors in relatively good financial status, social welfare organizations' image, trust and responsiveness positively have direct effects on organizational identification, which has a direct effect on continuing the sponsorship. That is, the image, trust and responsiveness influence the continuity of the sponsorship through the full mediating effect of organizational identification. On the other hand, among relatively poor donors, only the organizations' image and trust positively influence the organizational identification, The direct and indirect effects on the continuity of the sponsorship are different according to the private donors' financial status, which means that the moderating effect of the donors' financial status is proved. The result of latent mean analysis regarding 5 main latent variables according to the private donors' financial status, shows the significant difference in the continuity of sponsorship only(Mean= .197, Cohen's D=.779). By emphasizing that Organizational identification is a critical factor in terms of enhancing the continuity of sponsorship, some practical implications are discussed based on the study's findings.

• Geomechanics and Engineering
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• v.15 no.4
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• pp.947-955
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• 2018

In this study, we propose a three-dimensional simplified slope stability analysis using a hybrid-type penalty method (HPM). In this method, a solid element obtained by the HPM is applied to a column that divides the slope into a lattice. Therefore, it can obtain a safety factor in the same way as simplified methods on the slip surface. Furthermore, it can obtain results (displacement and strain) that cannot be obtained by conventional limit equilibrium methods such as the Hovland method. The continuity condition of displacement between adjacent columns and between elements for each depth is considered to incorporate a penalty function and the relative displacement. For a slip surface between the bottom surface and the boundary condition to express the slip of slope, we introduce a penalty function based on the Mohr-Coulomb failure criterion. To compute the state of the slip surface, an r-min method is used in the load incremental method. Using the result of the simple three-dimensional slope stability analysis, we obtain a safety factor that is the same as the conventional method. Furthermore, the movement of the slope was calculated quantitatively and qualitatively because the displacement and strain of each element are obtained.

• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.69-77
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• 2012

Surface insolation is one of the major indicators for climate research over the Earth system. For the climate research, long-term data and wide range of spatial coverage from the data observed by two or more of satellites of the same orbit are needed. It is important to improve the continuity and consistency of the derived products, such as surface insolation, from different satellites. In this study, surface insolations based on Geostationary Operational Environmental Satellite (GOES-9) and Multi-functional Transport Satellites (MTSAT-1R) were compared during overlap period using physical model of insolation to find ways to improve the consistency and continuity between two satellites through comparison of each channel data and ground observation data. The thermal infrared brightness temperature of two satellites show a relatively good agreement between two satellites : rootmean square error (RMSE)=5.595 Kelvin; Bias=2.065 Kelvin. Whereas, visible channels shown a quite different values, but it distributed similar tendency. And the surface insolations from two satellites are different from the ground observation data. To improve the quality of retrieved insolations, we have reproduced surface insolation of each satellite through adjustment of the Cloud Factor, and the Cloud Factor for GOES-9 satellite is modified based on the analysis result of difference channel data. As a result, the insolations estimated from GOES-9 for cloudy conditions show good agreement with MTSAT-1R and ground observation : RMSE=$83.439W\;m^{-2}$ Bias=$27.296W\;m^{-2}$. The result improved accuracy confirms that the modification of Cloud Factor for GOES-9 can improve the continuity and consistency of the insolations derived from two or more satellites.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.807-819
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• 2020

The purpose of this study is to investigate the relationship between the motivation to participate in sports for elderly, the factors for fun, leisure satisfaction, and exercise persistence. In order to analyze the data, a total of 200 questionnaires were distributed to senior citizens participating in sports programs at the Senior Citizen Welfare Center in Seoul, and a total of 183 copies (91.5%) of data were used as valid samples excluding 17 unfaithful responses. For data processing, frequency analysis, confirmatory factor analysis, Cronbach's α, concentration validity, discriminant validity, concept reliability, correlation analysis, and structural equation model verification were performed using IBM AMOS 21.First, the motivation to participate in sports for the elderly influenced the fun factor. Second, the motivation to participate in sports for the elderly influenced leisure satisfaction. Third, the motivation to participate in sports for the elderly influenced the exercise continuation. Fourth, the fun factor of sports for the elderly influenced leisure satisfaction. Fifth, the fun factor of elderly sports influenced the exercise continuation. Sixth, the satisfaction of sports for the elderly affected the exercise continuation.