• Journal of the Society of Naval Architects of Korea
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• v.52 no.4
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• pp.338-348
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• 2015

In this study, the added resistance of ships in short waves is systematically studied by using two different numerical methods - Rankine panel method and Cartesian grid method – and existing asymptotic and empirical formulae. Analysis of added resistance in short waves has been preconceived as a shortcoming of numerical computation. This study aims to observe such preconception by comparing the computational results, particularly based on two representative three-dimensional methods, and with the existing formulae and experimental data. In the Rankine panel method, a near-field method based on direct pressure integration is adopted. In the Cartesian grid method, the wave-body interaction problem is considered as a multiphase problem, and volume fraction functions are defined in order to identify each phase in a Cartesian grid. The computational results of added resistance in short waves using the two methods are systematically compared with experimental data for several ship models, including S175 containership, KVLCC2 and Series 60 hulls (C_B = 0.7, 0.8). The present study includes the comparison with the established asymptotic and empirical formulae in short waves.

• The Journal of Korean Academy of Sensory Integration
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• v.21 no.1
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• pp.34-46
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• 2023

Objective : The purpose of this study was to systematically analyze the methods by which virtual reality (VR)-based occupational therapy interventions are applied to disabled children and adolescents and to assess their effectiveness. Methods : The RISS, DBpia, KCI, Science Direct, and CINAHL MEDLINE databases were searched for relevant literature from January 2012 to August 2022. The main search terms used were "virtual reality," "work therapy," "youth," "virtual reality," "occupational therapy," "child," and "adolescent." A total of 16 documents were selected for analysis by the 4th stage of the PRISMA flowchart. Results : In the 16 selected studies, VR-based occupational therapy when used with children and adolescents with disabilities and was shown to have meaningful effects. Among the types of cerebral palsy covered in the studies, the most common was hemiplegia, and the evaluation tools used for measurement of the VR effect were daily activities, cognition, exercise technology, social-interaction technology, and visual-perception evaluation. Nintendo wii and Microsoft Kinect produced the VR tools most commonly used to improve motor skills and daily life. Conclusion : The results of this study indicate that VR interventions can be used effectively in clinical practice. In the future, they may assist in the diagnosis of disabled children and adolescents, in helping to select VR tools that are suitable for the purposes of intervention, and in the presentation of specific methods.

• The Journal of Korean Academy of Sensory Integration
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• v.12 no.1
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• pp.25-38
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• 2014

Objective : This study was conducted to determine effects of school-based occupational therapy through a systematic review Methods : We systematically reviewed studies published in PubMed and Ovid from 2000 to June 2014 using keyword 'school' or 'children' and 'occupational therapy'. Fourteen studies were selected. The level of evidence, participants, assessment, intervention area, method and effects were analyzed by reviewing full text. Results : The most group and age of participants were normal child with fine motor difficulties and 6~8 years old in selected studies. The most target area of intervention was handwriting, fine motor and visuo-motor integration (68.8%) and the most method was direct treatment (71.4%). The top on the assessment was Beery-Buktenica Test of Visual-Motor Integration (14.9%) and next was Bruininks-Oseretsky Test of Motor Proficiency (11.1%). Effects of school based occupational therapy were founded in the visual motor integration, learning skill, level of participation, fine motor, play and behavioral problem. Conclusion : This systematic review provides evidence concerning the participants, intervention, assessment and effects of school based occupational therapy. It should be used for basic data for the research and practice of school-based occupational therapy.

• Analytical Science and Technology
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• v.19 no.5
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• pp.400-406
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• 2006

Hydrogen analysis by elastic recoil detection has been performed utilizing polyimide film as a reference sample of known hydrogen content assuming the soundness of ion beam current integration. However beam current integration at higher incidence angle is not reliable. Scattering yield per unit fluence by current integration which is normalized per unit path length decreases as the sample tilt angle is getting higher. Moreover because beam current integration at high tilt angle is incomplete, hydrogen evaluation is very risky by direct comparison of sequentially collected recoil spectra between reference and target sample. In this study, primary ion beam dose is determined by backscattering spectrum that is collected simultaneously with recoil spectrum instead of ion beam current integration in order to reduce uncertainty arising in the process of current integration and to enhance the reliability of quantitative analysis. Three test samples are selected $-7.6{\mu}m$ polyimide film, hydrogen implanted silicondioxide and Au deposited carbon wafer- and analyzed by two methods and compared.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.688-695
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• 2005

The aim of this study is to develop a procedure to estimate the wind loads from the accelerations of a tall building structure. The wind loads may be directly calculated using the inverse analysis or simply integrating the wind pressures of the overall structure. But, these methods are too expensive and impossible to implement in some cases. In this study, a simple method is proposed to estimate the wind loads using the Kalman filter. This method is very stable compared to the direct integration of the acceleration to get the velocity or displacement. The proposed method is verified thorough numerical analysis, and results show that the proposed method is robust and estimates the wind loads accurately.

• Structural Engineering and Mechanics
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• v.51 no.6
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• pp.1067-1089
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• 2014

In this paper, three dimensional static and dynamic analyses of two dimensional functionally graded annular sector plates have been investigated. The material properties vary through both the radial and axial directions continuously. Graded finite element and Newmark direct integration methods have been used to solve the 3D-elasticity equations in time and space domains. The effects of power law exponents and different boundary conditions on the behavior of FGM annular sector plate have been investigated. Results show that using 2D-FGMs and graded elements have superiority over the homogenous elements and 1D-FGMs. The model has been compared with the result of a 1D-FGM annular sector plate and it shows good agreement.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.237-247
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• 2001

In this paper we present an overview of existing state of the art visualization techniques fur the interactive analysis of results from numerical simulations and measurements. We describe the basic concepts and key ideas behind these different visualization methods in this paper. The potential of these techniques for an efficient integration into a virtual reality environment will be investigated. Furthermore we present our first demonstrator fur visualizing multiparametric data and give an outlook on our plans for further exploiting and developing these techniques in an upcoming project.

• Journal of the Korean Data and Information Science Society
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• v.28 no.1
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• pp.207-215
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• 2017

In this paper we study pooling effects in Bayesian testing procedures of independence for contingency tables from small areas. In small area estimation setup, we typically use a hierarchical Bayesian model for borrowing strength across small areas. This techniques of borrowing strength in small area estimation is used to construct a Bayes test of independence for contingency tables from small areas. In specific, we consider the methods of direct or indirect pooling in multinomial models through Dirichlet priors. We use the Bayes factor (or equivalently the ratio of the marginal likelihoods) to construct the Bayes test, and the marginal density is obtained by integrating the joint density function over all parameters. The Bayes test is computed by performing a Monte Carlo integration based on the method proposed by Nandram and Kim (2002).

• Journal of the Korean Society for Precision Engineering
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• v.23 no.9 s.186
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• pp.76-83
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• 2006

Machining accuracy is closely related with tool deflection induced by cutting forces. In this research, cutting forces and tool deflection in end milling are expressed as a closed form of tool rotational angle and cutting conditions. The discrete cutting fores caused by periodic tool entry and exit are represented as a continuous function using the Fourier series expansion. Tool deflection is predicted by direct integration of the distributed loads on cutting edges. Cutting conditions, tool geometry, run-outs and the stiffness of tool clamping part are considered together far cutting forces and tool deflection estimation. Compared with numerical methods, the presented method has advantages in prediction time reduction and the effects of feeding and run-outs on cutting forces and tool deflection can be analyzed quantitatively. This research can be effectively used in real time machining error estimation and cutting condition selection for error minimization since the form accuracy is easily predicted from tool deflection curve.

• Korean Journal of Adult Nursing
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• v.28 no.4
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• pp.415-423
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• 2016

Purpose: This study was designed to identify the structural relationships among psychosocial variables related to sick role behavioral compliance among patients undergoing hemodialysis. Methods: The subjects were 476 patients from seven major hospitals and twelve dialysis centers located in D and P cities. Data were collected using self-report questionnaires. Data analysis was done by using SPSS/WIN 18.0 and AMOS 18.0 programs for structural equation modeling, to estimate the hypothesized model. Results: This findings support that a modified path model is efficient and appropriate to explain sick role behavioral compliance among hemodialysis patients. These factors account for 80.1% of the variance of sick-role behavioral compliance among hemodialysis patients. The variables having direct effect on sick role behavioral compliance were knowledge related to hemodialysis, social support, attitude, self-efficacy and intention. Conclusion: The modified model explains the integration process of psychosocial and behavior variables for sick-role behavioral compliance among patients undergoing hemodialysis.