• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.1
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• pp.29-35
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• 1990

This paper proposes a tow-dimensional magnetic flux distribution analysis of the double-sided linear induction motor(DLIM). Both the longitudinal end-effect and the transverse edge-effect, which are due to the finite length and width of the primary stator, are considered. Also each force which is due to the variation of slip frequency was computed to show the fact that the thrust force of DLIM is dependent on both the longitudinal end-effect and the transverse edge-effect. To ascertain the propriety of this analysis, the simulated results of the magnetic flux density distribution in the airgap are compared to the experimental data.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.677-684
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• 2016

This study was carried out to confirm the effects of the knife-incising and longitudinal kerfing treatment on high-temperature drying characteristics of red pine square timber with dimensions of thickness 15 cm. The range of final moisture content was investigated 5.6% to 7.5% after drying. The differences did not exist in the moisture content and distribution according to the pretreatment condition. In the case of longitudinal kerfing treatment, the surface check occurrence was reduced than the control. In addition, the twist had a tendency to decrease due to the longitudinal kerfing treatment. The knife-incising and longitudinal kerfing treatment were investigated to be ineffective on internal checks and drying shrinkage.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.5
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• pp.667-676
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• 2006

This study was conducted to evaluate the effect of longitudinal baffle on hydrodynamic behavior within a certain full-scale sedimentation basin (flow rate per basin; $1,000m^3/d$). Comparative experimental investigations have been carried out on the sediment removal efficiencies and the sludge deposit distribution in the baffled and un-baffled sedimentation basin, respectively. From the results derived in the baffled and un-baffled sedimentation, the turbidity removal rate in the baffled sedimentation basin is about 38% higher than that in un-baffled. Also, the height of sludge deposit in the baffled sedimentation basin is approximately 20% lower, and the sludge concentration is 10% higher than those in un-baffled sedimentation basin. In order to explain the experimental results and investigate the effect of longitudinal baffle in more detail, we conducted Computational Fluid Dynamics (CFD) simulation. From the results of CFD simulation, the flow, especially in the near of outlet orifice, was more stable in the case of longitudinal baffled sedimentation basin than that in un-baffled basin. Also, it could be concluded that the longitudinal baffle made a fully developed flow more effective for sedimentation.

• Journal of Korean Society of Steel Construction
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• v.13 no.6
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• pp.621-629
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• 2001

This study consists of static and fatigue tests to evaluate the behavior on the field splice joint of longitudinal rib in orthotropic steel deck specimens. Specifically, static and influence surface tests are performed for the stress distribution at the scallop area and high-strength bolt connection of longitudinal rib to examine the existence of handhole cover plate and the effect of eccentric loads. The ultimate strength of the field splice joint of longitudinal rib is obtained. In fatigue tests, cracks are observed at the scallop in the lower level test and the catastrophic failure of longitudinal rib is occurred following the failure of handhole cover plate in the higher level test. This study gives a basis for the better understanding of the field splice joint of longitudinal rib.

• Journal of Wetlands Research
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• v.11 no.2
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• pp.89-98
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• 2009

This study determines the stream mean slope, stream slope and longitudinal stream profile based on the concept of informational entropy. Maximizing the entropy will make the probability distribution of longitudinal stream profile as uniform as possible while satisfying the constraints. Using this relationships the mean stream slope, stream slope and longitudinal stream profile formulas were derived. The parameters of the applied streams were estimated by the least square method using the geomorphological factors of Dalchon stream basin obtained from Chungcheong Buk-Do local stream consolidation scheme drawings. The comparative investigation was performed between the observed and simulated mean stream slope and longitudinal stream profile, and are in good agreement with the measured data. It is noted that this results can be used in the estimation of stream mean slope and longitudinal stream profile.

• Communications for Statistical Applications and Methods
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• v.24 no.3
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• pp.255-269
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• 2017

This article explores the analysis of longitudinal surveys in which same units are investigated on several occasions. Multivariate exponential ratio type estimator has been proposed for the estimation of the finite population median at the current occasion in two occasion longitudinal surveys. Information on several additional auxiliary variables, which are stable over time and readily available on both the occasions, has been utilized. Properties of the proposed multivariate estimator, including the optimum replacement strategy, are presented. The proposed multivariate estimator is compared with the sample median estimator when there is no matching from a previous occasion and with the exponential ratio type estimator in successive sampling when information is available on only one additional auxiliary variable. The merits of the proposed estimator are justified by empirical interpretations and validated by a simulation study with the help of some natural populations.

• Electrical & Electronic Materials
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• v.10 no.4
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• pp.342-348
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• 1997

In this paper, the behavior of electron swarm parameters and energy distribution function of the discharge under high E/N condition in e$^{-10}$ -CF$_{4}$ gas have been analysed over the E/N range from 1-300(Td) by the MCS and BEq methods using set of electron collision cross section determined by the authors. The swarm parameters and energy distribution function have been calculated for the pulsed Townsend, steady-state Townsend and Time of Flight methods. The results gained that the value of electron swarm parameters such as the electron drift velocity, the electron ionization and attachment coefficients and longitudinal diffusion coefficients in agreement with the experimental and theoretical data for a range of E/N. The electron energy distribution function has been explained and analysed in e$^{-10}$ -CF$_{4}$ at E/N : 5, 10, 100, 200, 300(Td) for a case of the equilibrium region in the mean electron energy and respective set of electron collision cross sections. The validity of the results has been confirmed by TOF and SST methods.

• Korean Journal of Child Studies
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• v.26 no.5
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• pp.263-279
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• 2005

This study explored the participant roles and the cross-sectional and longitudinal relationships between interpersonal behavior characteristics and bullying/victimization. The subjects were 4th and 5th grade children and instruments were the Participant Roles Scale, Self-Report Coping Scale, Teenage Inventory of Social Skills, and Social Anxiety/Avoidance. They were contacted again one year later. In the distribution of participant roles at Time 1, defender of the victim was highest, then outsider; at Time 2 outsider was the highest and then defender. There was a tendency of gender difference in distribution of participant roles only at Time 1. Males were more in the group of reinforcer; females were more in the group of defender and victim. There were high positive correlations among bully/reinforcer/assistant scores. In the concurrent view, children who used approach coping strategies and showed higher social skills were more likely to be defender. Children who had lower social skills and higher social anxiety and social avoidance were more likely to be victim. In the longitudinal view, children who had developed higher social skills were more likely to be defender. Children who had employed less approach coping strategies and had showed lower social skills and higher social avoidance were more likely to be victim.

• The Korean Journal of Applied Statistics
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• v.30 no.2
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• pp.203-213
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• 2017

We study estimation and inference of joint conditional distributions of bivariate longitudinal outcomes using regression models and copulas. We consider a class of time-varying transformation models and combine the two marginal models using Gaussian copulas to estimate the joint models. Our models and estimation method can be applied in many situations where the conditional mean-based models are inadequate. Gaussian copulas combined with time-varying transformation models may allow convenient and easy-to-interpret modeling for the joint conditional distributions for bivariate longitudinal data. We apply our method to an epidemiological study of repeatedly measured bivariate cholesterol data.

• Steel and Composite Structures
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• v.30 no.6
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• pp.567-576
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• 2019

Time-dependent creep analysis of a rotating functionally graded cantilever beam with trapezoidal longitudinal cross section subjected to thermal and inertia loading is investigated using first-order shear deformation theory (FSDT). The model described in this paper is a simple simulation of a turbine blade working under creep condition. The material is a metal based composite reinforced by a ceramic where the creep properties of which has been described by the Sherby's constitutive model. All mechanical and thermal properties except Poisson's ratio are assumed to be variable longitudinally based on the volume fraction of constituent. The principle of virtual work as well as first order shear deformation theory is used to derive governing equations. Longitudinal distribution of displacements and stresses are investigated for various volume fractions of reinforcement. Method of successive elastic solution is employed to obtain history of stresses and creep deformations. It is found that stresses and displacements approach their steady state values after 40000 hours. The results presented in this paper can be used for selection of appropriate longitudinal distribution of reinforcement to achieve the desired stresses and displacements.