• Steel and Composite Structures
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• v.52 no.1
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• pp.1-14
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• 2024

This paper introduces a system allows for seismic isolation of the pallet from the rack in the down-aisle direction, occupies minimal vertical space (5 cm) and ±7.5 cm of deformation range. A conceptual model of the isolation system is presented, leading to a constitutive equation governing its behavior. A first experimental campaign studying the response of the isolation system's components was conducted to calibrate the parameters of its constitutive equation. A second experimental campaign evaluated the response of the isolation system with mass placed on it, subjected to cyclic loading. The results of this second campaign were compared with the numerical predictions using the pre-calibrated constitutive equation, allowing a double-blind validation of the constitutive equation of the isolation system. Finally, a numerical evaluation of the isolation system subjected to a synthetic earthquake of one component. This evaluation allowed verifying attributes of the proposed isolation system, such as its self-centering capacity and its effectiveness in reducing the absolute acceleration of the isolated mass and the shear load transmitted to the supporting beams of the rack.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.2
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• pp.418-430
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• 2014

In this paper, a modelling technique for simulating self-propelled ships in waves is presented. The flow is modelled using a RANS solver coupled with an actuator disk model for the propeller. The motion of the ship is taken into consideration in the definition of the actuator disk region as well as the advance ratio of the propeller. The RPM of the propeller is controlled using a PID-controller with constraints added on the maximum permissible RPM increase rate. Results are presented for a freely surging model in regular waves with different constraints put on the PID-controller. The described method shows promising results and allows for the studying of several factors relating to self-propulsion. However, more validation data is needed to judge the accuracy of the model.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.6
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• pp.454-461
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• 2000

Electrostatic suspension offers an advantage of directly suspending various materials such as conductive materials, semiconductors and dielectric materials without any mechanical contacts. This is a specific feature compared with electromagnetic suspension which can suspend only ferro-magnetic material. In general, the electrostatic suspension systems require position sensors for stabilizing the suspended object. Therefore, a lot of displacement sensors and a switching circuit are required for moving the object through a long distance. In order to circumvent this problem, this paper proposes a self-sensing method which can provide the gap displacement between electrodes and suspended object without external sensors. Moreover a simple on-off controller is presented for stabilization. Experimental validation of the proposed scheme has been performed through the successful levitation of a 4-inch silicon wafer.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.142-147
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• 2008

This paper reports an analysis of self-pressurization in a closed cryogenic liquid storage system and its comparison with experimental data using liquid nitrogen. Partial equilibrium model(PEM), revised thermodynamic analysis of homogeneous model, has been applied for the pressurization in a closed tank. The vapor and liquid bulk temperature and the liquid-vapor interface temperature are separately calculated as their own representative values in this analysis. The analysis results of the partial equilibrium model are compared with the experimental data and other preceding homogeneous temperature models for validation.

• Journal of the Optical Society of Korea
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• v.19 no.6
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• pp.638-642
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• 2015

We present a simple method to determine the focal distances of lenses with the Talbot self-images. This method uses only one grating, and a priori knowledge of the period of the grating is replaced with a linear relation between the (de)magnified periods of the Talbot images and the lens-to-grating distance. A thick lens whose effective focal length is 500 mm was used to validate the method, and the focal distance of the converging beam was determined with the difference of 0.15% for the nominal focal distance of 521.9 mm. The determined period of the grating with the difference of 0.2% also supports the validation.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.923-931
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• 2009

The purpose of this study is to testify construct validity of Self-directed Learning Perception Inventory for middle school students(Lee, 2008). For the purpose, First, test was done with 1202 middle students sampled from nationwide. As a result of confirmatory factor analysis using structural equation model, we confirmed 7 factor model was generally appropriate and acceptable. Second, in order to test criterion-related validity, test was done with 530 middle school students sampled form Seoul, Gyeonggido, Chungchongdo. The inventory has criterion-related validity enough to be a tool for measurement. Reliability of this inventory was .94 and retest reliability was .91. The limitation of this and suggestion for future research were discussed.

• The Journal of the Korea Contents Association
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• v.20 no.9
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• pp.577-588
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• 2020

The purpose of this study is to conduct the Korean translation and validity of the Unconditional Positive Self-Regard Scale(UPSR) that Patterson and Joseph(2006) originally developed based on the Rogerian person-centered theory. K-UPSR was adapted, modified and validated from the UPSR Scale. This study verified reliability and validity, and factor structure of K-UPSR. The preliminary study was proceeded with twelve adapted questions to 131 undergraduate and graduate students. As a result, three questions were deleted for the low reliability. The exploratory factor analysis of the nine questions showed two sub factors. The internal consistency reliability of nine questions with two sub factors was .89 in this study. The study was conducted by 419 male and female adults and verified confirmatory factor analysis and the validity. The study data was evaluated for the suitability of convergent and discriminant validity of K-UPSR. Through the correlation analysis of other five scales, the result was mostly corresponded to the preliminary study.

• The Journal of the Korea Contents Association
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• v.22 no.7
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• pp.583-598
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• 2022

This study is a follow-up study of the Social Media Emotional Contagion(SECS) and it aims to validate the Social Media Emotional Contagion Scale(SECS) through CFA and criterion-related validity. The data was collected from 326 people in 20s. The criterion-related validity of SECS were confirmed with the Korean version of the Emotional Contagion Scale(K-ECS), the Basic Empathy Scale in Adult(BES-A), and the Rosenberg Self-esteem Scale(SES). As a result, the K-ECS and sub-factor of Emotional Contagion of BES-A, which are the same as the construction of SECS, converged. Other scales were differentiated from SECS. However, sub-factor of SES of positive self-esteem, which are the same as the construction of SECS, converged. Also, sub-factor of SES of negative self-esteem, which are the same as the construction of SECS of negative Emotional Contagion, converged. Finally, the significance and limitations of this study and future studies were discussed.

• Journal of the Korean Society of Clothing and Textiles
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• v.46 no.4
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• pp.704-722
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• 2022

Current studies validate the Body Positive Scale (BP Scale) as a self-assessment instrument that captures four dimensions of the positive body image construct. We developed and evaluated a 17-item BP Scale using two focus group interviews and four independent samples (n = 1,379) of Korean women who completed online survey questionnaires. We generated an initial pool of items via literature review, content validation with experts, and focus group interviews, subsequently refining the items through exploratory analysis (Study 1). We confirmed the BP Scale's underlying dimensions with young Korean female samples (Study 2, Study 4) and with a community sample (Study 3). We also examined the construct validity, internal consistency, and test-retest reliability over a six-week interval. Overall, the results supported that the four-factor BP Scale demonstrates adequate validity and reliability in measuring positive body image among Korean women. The BP Scale provides a method for researchers and practitioners to understand and assess individuals' positive body image in a multifaceted manner.

• Journal of Korean Academy of Nursing
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• v.19 no.3
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• pp.273-284
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• 1989

The aim of this investigation was to delineate concepts contributing to the Exercise of Self-Care Agency (E.S.C.A.) Scale developed by Kearney & Fleischer (1979) and to test its construct validity and its predictors. The results are summarized as follows ; 1. By means of principal factor analysis and maximal likelihood factor analysis upon data generated from 280 undergraduate students, the factors of Concern about Health Knowledge, self-Concept, Information - Seeking Behavior, Decision -making and Responsibility, Self-esteem, and Passivity emerged. The total percent of variance explained by the 6 factors was 75.1% 2. To assess factor independence and instrument homogeneity, correlations among the 6 factors were computed. The correlations ranged from .24 to .46 indicating that the factors and the items were not too similar or redundant. 3. Test-retest reliability of the total scale is r＝.70. Cronbach's $\alpha$ coefficient for internal consistency of the total scale is .86 and that of the factors ranged from .750 to .661 (only factor 6 .497). 4. In additional analysis of the Exercise of Self-Care Agency Scale in relationship to Multiple Health Locus of Control, Family Environmental Scale, and Cornell Medical Index using stepwise multiple regression, the Internal Health Locus of Control Score predicted 21.8%(F＝53.34, p＝.0001), Family Environmental Score 8.3%(F＝22.59, P＝.0001), Modified Cornell Medical Index Score 5.4%(F＝15.74, P＝.0001) of the score of the E.S.C.A.