• Interaction and multiscale mechanics
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• v.1 no.3
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• pp.317-328
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• 2008

When carbon-filled rubber specimens are subjected to cyclic loading, they do not return to their initial state after loading and subsequent unloading, but exhibit a residual strain or permanent deformation. We propose a specific form of the pseudo-elastic energy function to represent cyclic loading for incompressible, isotropic materials with stress softening and residual strain. The essence of the pseudo-elasticity theory is that material behaviour in the primary loading path is described by a common elastic strain energy function, and in unloading, reloading or secondary unloading paths by a different strain energy function. The switch between strain energy functions is controlled by the incorporation of a damage variable into the strain energy function. An extra term is added to describe the permanent deformation. The finite element implementation of the proposed model is presented in this paper. All parameters in the proposed model and elastic law can be easily estimated based on experimental data. The numerical analyses show that the results are in good agreement with experimental data.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.164-177
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• 2013

This study's aim was to attest social support and self-efficacy's mediation effects in the path which social participation affected to elderly's suicidal ideation. Analysis data were Seoul Welfare Panel Data 2th wave(2010). A total of 1,429 cases aged over 65 were used for this study. Analysis method was AMOS 18.0's Structural Equation Modeling, and sobel test was used for attesting mediation effects's significance degree. Analysis results had established that measurement model and structural model's fit was favorable, and all path coefficients had significance degree. Therefore, this model was suitable for this study. Also this results had proved that this study's model was full mediation model, and it means that if mediation variables controlled, and then direct effect was excluded. And analysis results confirmed social support and self-efficacy' mediation effect had significance, by using a sobel test. Based on analysis results, this study suggested the importance of relationship between secondary group and individual, and presented intervention plans.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.2
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• pp.53-62
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• 2021

PURPOSE: Social participation is essential for stroke survivors. Although participation restrictions are affected by several factors, a few studies have focused on the effects of living in a particular residential area (urban versus rural) on the participation restrictions after a stroke. This study examined the factors affecting participation restrictions in stroke survivors according to the residential area. METHODS: One hundred sixty-six stroke patients (including 130 living in urban areas and 36 living in rural areas) were recruited for this study. The Korean Modified Barthel Index (K-MBI) was used to assess the activities of daily living (ADL). The Korean Mini-Mental Examination Status (MMSE-K) was used to assess cognition. The motor function was evaluated using the Fugl-Meyer function assessment (FMA). Path analysis was used to test the hypothesized model of participation restriction. RESULTS: The proposed path model showed good fit indices. In rural and urban areas, the direct effects were significant between the ADL and participation restrictions (β = -.673 and -.457, respectively). For urban areas, the direct effects were significant between cognition and participation restrictions (β = -.252). In both area types, motor function and cognition had a significant direct effect on the ADL. CONCLUSION: For urban community-dwelling stroke survivors, the ADL and cognition had direct effects on participation restrictions. For rural area stroke survivors, the ADL had direct effects on participation restrictions. Activity level exercise programs help reduce the participation restrictions. Moreover, it is essential to address cognition training to improve participation in urban community-dwelling stroke survivors.

• The Journal of the Korea Contents Association
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• v.20 no.3
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• pp.41-48
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• 2020

The purpose of this study is testing measurement invariance of the school vitality scale across the level of school. For this study, 3,156 elementary school teachers and 4,411 secondary school teachers were surveyed. As a result, school vitality scale was found to have the same factor structure in the structure regression model. Second, the factor load of the measurement model was found to be the same. Third, the structural path coefficients were the same. Fourth, structural covariance was found to be the same. Fifth, the structural residuals were the same. Based on these findings, it can be concluded that we can use school vitality scale both elementary school and secondary school. This study will contribute to diagnosing school vitality levels and finding ways to improve school management.

• 한국노년학
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• v.29 no.1
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• pp.243-258
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• 2009

Background: Falls are among the most common and serious health problems of older people. The psychological symptoms of falling have received relatively little attention compared to physical problems. Objective: The purpose of this study is to test a model to explain the factors that influence fear of falling among older adults living in a continuing care retirement community (CCRC) in Baltimore city, United States. Methods: A secondary analysis was conducted using data obtained from a Health Promotion Survey done on 149 older adults living in a CCRC. Data was originally obtained during face to face interviews with each participant. Descriptive statistics and bivariate correlations were used to describe the sample and evaluate simple correlations. A path analysis was done using the AMOS 4.0 statistical program. Results: Of the 49 hypothesized paths, 13 were statistically significant, and the model accounted for 22% of the variance in fear of falling among the elderly. There was support for the fit of the model to the data with a nonsignificant chi square at 0.478 (df=2, p=0.79), and the ratio of chi-square to degrees of freedom was 0.24, a CFI of 0.99 and RMSEA of 0.00. In particular, gender, a history of falling, and exercise were significant predictors of fear of falling. Conclusions/Implications: As anticipated, exercise is an important factor to prevent fear of falling. As a modifiable variable, self-efficacy and outcome expectation indirectly influence fear of falling through exercise.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.8
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• pp.442-450
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• 2000

Active noise control is an approach to noise reduction in which a secondary noise source that destructively interferes with the unwanted noise. In general, active noise control systems rely on multiple sensors to measure the unwanted noise field and the effect of the cancellation. This paper develops an approach that utilizes a single sensor. The noise field is modeled as a stochastic process, and a time-adaptive algorithm is used to adaptively estimate the parameters of the process. Based on these parameter estimates, a canceling signal is generated. Opppenheim model assumed that transfer function characteristics from the canceling source to the error sensor is only propagation delay. But this paper proposes a modified Oppenheim model by considering transfer characteristics of acoustic device and noise path. This transfer characteristics is adaptively cancelled by adaptive model. This is proved by computer simulation with artifically generated random noise and sine wave noise. The details of the proposed architecture, and theoretical simulation and experimental results of the noise cancellation system for three dimension enclosure are presented in the paper.

• Water for future
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• v.23 no.4
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• pp.435-444
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• 1990

The flow characteristics varying with the rate of the radius of curvature to width (Rc/B) in open channel bends are investigated with a simplified numerical model, briefly. Secondary flow velocity and transverse bed slope are formulated from the equations of moment of momentum and force balance analysis, respectively. The conservation equations of mass and streamwise momentum are simplified by depth integration and its solution could be obtained form explicit finite difference method. Three sets of computer simulation are executed. The rates of Rc/B adopted in simulations are 2.7, 5.4, 8.1 , respectively. The terms analyzed in this paper are secondary flow velocity, streamwise velocity, the path of maximum streamwise velocity, deviation angle, and mass-shift velocity.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.1964-1966
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• 2001

Active Noise control(ANC) is rapidly becoming the most effective way to reduce noises that can otherwise be very difficult and expensive to control. This research presents ANFIS (Adaptive Network Fuzzy Inference System) controller for adaptively noise cancelling in a duct. ANC system generates secondary control sound pressure with same amplitude and with opposite phase as noise to be eliminated. ANFIS controller is trained to optimize its parameters for adaptively cancelling noise. That is ANFIS train its parameters by gradient descent and LSE method so called hybrid method. This paper present ANFIS in active noise control which provides an improvement convergence speed and limitation of linearity condition. It can model nonlinear functions of arbitrary complexity and ANFIS can construct an input-ouput mapping based on both human knowledge in the form of Takagi and Sugeno's fuzzy if-then rules and stipulated input-output data pairs. This paper also shows that the proposed ANFIS active noise control system successfully cancelled noise.

• Journal of Korean Academy of Nursing
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• v.53 no.2
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• pp.249-259
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• 2023

Purpose: Based on the Reserve Capacity Model, this study investigated the effects of pre- and postmenopausal women's socioeconomic status (SES) on depression, focusing on the mediating effects of self-esteem, happiness, and family relationship satisfaction with social network relationships. Methods: This cross-sectional study involved secondary analysis of national data on 771 perimenopause women gathered from the 16th Korea Welfare Panel Study (KOWEPS) 2021. A path analysis model was constructed to evaluate the relationship between SES, social network satisfaction, self-esteem, perceived health status, and depression. Data were analyzed using ADANCO 2.3.1 and Mplus 8.4. Results: Although SES had no direct effect on depression, it did affect depression through self-esteem, happiness, and satisfaction with family relationships. Conclusion: The findings of this study indicate that perimenopausal women's personal resources—psychosocial variables such as self-esteem and happiness—had a higher effect on depression than tangible reserves like SES. Therefore, interventions for enhancing self-esteem and happiness may prevent depression in perimenopausal women effectively.

• Journal of the Korea Society of Computer and Information
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• v.18 no.7
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• pp.183-190
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• 2013

This study aims to analyze the relationships among factors which influence acceptance intention of smart education. Based on literature reviews related with previous technology acceptance models, a potential model and seven hypotheses were suggested. Questionnaire was carried out among 132 students from elementary and secondary schools. They have experiences of utilizing applications of mobile devices for instructional goal. Cronbach alpha of the questionnaire was .78. The collected data were analyzed through path analysis. The results of this research are as follows. Seven hypotheses were adopted: Interaction will affect on perceived usefulness, Interaction will affect on perceived ease of use, Interaction will affect on acceptance intention, Interaction will affect on social influence, Social influence will affect on perceived usefulness, Perceived usefulness will affect on acceptance intention, Perceived ease of use will affect on acceptance intention. The model revised through the results of path analysis had good-fitness. That is, overall fit measures (RMSEA, CFI, NNFI), indexes that show the suitability of the model were quite good.