• Journal of Korean society of Dental Hygiene
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• v.21 no.1
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• pp.27-40
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• 2021

Objectives: This study investigated the working conditions of dental hygienists and their challenges in providing oral care to older adults with dementia using focus group interviews. Methods: We collected data for approximately a month beginning from August 2020 and divided the study subjects into two groups: the health dental hygienist and the clinical dental hygienist groups. A total of 11 subjects participated in this study. Results: The oral health management of older adult patients with dementia has not been efficiently carried out in local communities or dental medical institutions. In addition, dental hygienists encounter difficulties in managing the oral health of these patients and hope to actively learn more about their special cases. Conclusions: Based on the results of this study, it is necessary to develop a manual or program for the professional implementation of oral health interventions for older adults with dementia.

• Korean Journal of Applied Biomechanics
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• v.32 no.4
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• pp.141-146
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• 2022

Objective: The purpose of this study was to investigate the effects of different frequency on muscle function of the thigh in patients with degenerative knee arthritis during the functional electrical stimulation (FES). Method: For this study, 16 male participants over 65 who patients with degenerative knee arthritis were recruited as research participants. In this research, isokinetic muscular function, EMG, and joint position sensation were performed after FES treatment was applied for three conditions (FES 20, FES 50, and Without FES). For each dependent variable, one-way ANOVA with repeated measures was to determine whether there were significant differences among three different conditions (p<.05). When a significant difference was found, post hoc analyses were performed by using the contrast procedure. Results: When compared to FES 50 and without FES, FES 20 causes significant increase in isometric knee extension strength. No significant differences were found in EMG values across different EMS conditions. Conclusion: The present study examined isokinetic muscular function, EMG, and joint position sensation in order to investigate the effects of different frequency muscle function of knee extensors during the functional electrical stimulation. The results of this study showed that FES with 20 Hz frequency had positive effect on knee extensor. Based on the findings of the present study, FES with lower frequency may help the performer to focus on developing strength in knee extensor muscles.

• Wind and Structures
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• v.29 no.6
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• pp.371-387
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• 2019

In the present paper, a simple refined nth-higher-order shear deformation theory is applied for the free vibration analysis of laminated composite plates. The proposed displacement field is based on a novel kinematic in which include the undetermined integral terms and contains only four unknowns, as against five or more in case of other higher-order theories. The present theory accounts for adequate distribution of the transverse shear strains through the plate thickness and satisfies the shear stress-free boundary conditions on the top and bottom surfaces of the plate, therefore, it does not require problem dependent shear correction factor. The governing equations of motion are derived from Hamilton's principle and solved via Navier-type to obtain closed form solutions. The numerical results of non-dimensional natural frequencies obtained by using the present theory are presented and compared with those of other theories available in the literature to verify the validity of present solutions. It can be concluded that the present refined theory is accurate and efficient in predicting the natural frequencies of isotropic, orthotropic and laminated composite plates.

• Korean Journal of Mathematics
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• v.22 no.4
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• pp.699-709
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• 2014

In the present paper, we investigate starlikeness conditions for q-differential operator by using the concept of quantum calculus in the unit disk.

• Honam Mathematical Journal
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• v.46 no.2
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• pp.307-312
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• 2024

In this paper, we present useful characterizations for Noetherian modules using the theory of prime submodules.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.10
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• pp.833-844
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• 2018

This paper aims to predict the aerodynamic characteristics of individual rotor for the gust and flight conditions. Transformation procedure into the wind frame is conducted to analyze the gust. Hover, forward, and climb flight conditions of an individual rotor are analyzed using the blade element momentum theory (BEMT) considering the rigid blade flapping motion. XFOIL is used to derive aerodynamic results. Validation for hover, forward flight, and climb conditions are conducted using the present BEMT. In addition, a static experimental environment is constructed. The experimental results and the present BEMT are compared and verified.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.6
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• pp.641-654
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• 2017

The KVLCC2 and its modified hull form were investigated in regular head waves using Unsteady Reynolds Averaged Navier-Stokes (URANS) methods. The modified KVLCC2 (named KWP-bow KVLCC2) is designed for reducing wave reflection from the bow. Firstly, the original KVLCC2 is studied for verification of the present code and methodology and the computed time history of total resistance and 2DOF motions (heave and pitch) for the selected two wave length conditions are directly compared with the results obtained from KRISO towing tank experiment under the identical condition. The predicted added resistance, heave and pitch motion RAOs show relatively good agreement with the experimental results. Secondly, the comparison of performance in waves between KVLCC2 and KWP-bow KVLCC2 is carried out. We confirmed that newly designed hull form shows better performances in all the range of wave length conditions through both the computation and the experiment. The present URANS method can capture the difference of performance in waves of the two hull forms without any special treatment for short wave length conditions. It can be identified that KWP-bow KVLCC2 gives about 8% of energy saving in sea state 5 condition.

• Steel and Composite Structures
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• v.18 no.3
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• pp.583-601
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• 2015

In the present study, the combined effects of thermal and mechanical loadings on the interlaminar shear stresses of both moderately thin and thick composite laminated beams are numerically analyzed. The finite element modelling of laminated composite beams and analysis of interlaminar stresses are performed using the commercially available software package MSC NASTRAN/PATRAN. The validity of the finite element analysis (FEA) is demonstrated by comparing the experimental test results obtained due to mechanical loadings under the influence of thermal environment with those derived using the present FEA. Various parametric studies are also performed to investigate the effect of thermal loading on interlaminar stresses generated in symmetric, anti-symmetric, asymmetric, unidirectional, cross-ply, and balanced composite laminated beams of different stacking sequences with identical mechanical loadings and various boundary conditions. It is shown that the elevated thermal environment lead to higher interlaminar shear stresses varying with the stacking sequence, length to thickness ratio, ply orientations under identical mechanical loading and boundary conditions of the composite laminated beams. It is realized that the magnitude of the interlaminar stresses along xz plane is always much higher than those of along yz plane irrespective of the ply-orientation, length to thickness ratios and boundary conditions of the composite laminated beams. It is also observed that the effect of thermal environment on the interlaminar shear stresses in carbon-epoxy fiber reinforced composite laminated beams are increasing in the order of symmetric cross-ply laminate, unidirectional laminate, asymmetric cross-ply laminate and anti-symmetric laminate. The interlaminar shear stresses are higher in thinner composite laminated beams compared to that in thicker composite laminated beams under all environmental temperatures irrespective of the laminate stacking sequence, ply-orientation and boundary conditions.

• Bulletin of the Korean Mathematical Society
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• v.52 no.5
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• pp.1495-1515
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• 2015

This paper deals with the numerical methods for the reconstruction of the source term in a linear parabolic equation from final overdetermination. We assume that the source term has the form f(x)h(t) and h(t) is given, which guarantees the uniqueness of the inverse problem of determining the source term f(x) from final overdetermination. We present the regularization methods for reconstruction of the source term in the whole real line and with Neumann boundary conditions. Moreover, we show the connection of the solutions between the problem with Neumann boundary conditions and the problem with no boundary conditions (on the whole real line) by using the extension method. Numerical experiments are done for the inverse problem with the boundary conditions.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.61-62
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• 2003

In this paper, the new higher order wall boundary conditions are proposed for solving the incompressible flows. The square driven cavity flows are simulated by using the variable order method of lines with the present wall boundary conditions. The variable order method of lines is constructed by the spatial discretization, i.e., the variable order proper convective scheme for convective terms and the modified differential quadrature method for diffusive terms, and time integration. The 2nd, 4th, and 6th order solutions are presented and these results show this higher order boundary conditions are very promising for the incompressible flow simulations.