• Journal of the Korean Society of Safety
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• v.34 no.4
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• pp.15-21
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• 2019

In order to secure the safety of various machinery, it is very important to develop a technique for accurately and quickly measuring the cracks generated in the mechanical equipment and evaluating the mechanical characteristics. The evaluation of the mechanical properties is accompanied by an appropriate strain measurement according to the material and crack occurrence of the target structure. Especially, when micro cracks are generated, the evaluation method is very important. Digital image correlation is an optical full field displacement measuring method which is using currently with speckles in the interested area. However the evaluation method and conditions of image distributions have to be considered carefully to measure the crack occurrence because the images of the speckle patterns affect the quality of displacement results. In this study, the speckle pattern density is characterized to improve the accuracy of the measurement method. And also the micro crack initiation is detected by the measured displacement in the adopted speckle pattern distribution. It is shown that the proposed method is useful to determine the density pattern distribution for the accurate measurement and crack detection.

• Nuclear Engineering and Technology
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• v.53 no.10
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• pp.3229-3235
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• 2021

The key process used in nuclear industries for the management of radiotoxicity associated with spent fuel in a closed fuel cycle is solvent extraction. An understanding of hydrodynamics and mass transfer is of primary importance for the design of mass transfer equipment used in solvent extraction processes. Understanding the interfacial phenomenon and the associated hydrodynamics of the liquid drops is essential for model-based design of mass transfer devices. In this work, the phenomenon of drop formation at the tip of a nozzle submerged in quiescent immiscible liquid phase is revisited. Previously reported force balance based models and empirical correlations are analyzed. Experiments are carried out to capture the process of drop formation using high-speed imaging technique. The images are digitally processed to measure the average drop diameter. A correlation based on the force balance model is proposed to estimate drop diameter and jet length. The average drop diameter obtained from the proposed model is in good agreement with experimental data with an average error of 6.3%. The developed model is applicable in both the necking as well as jetting regime and is validated for liquid-liquid systems having low, moderate and high interfacial tension.

• The Journal of Korean Academic Society of Nursing Education
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• v.25 no.3
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• pp.321-330
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• 2019

Purpose: The purpose of this study was to analyze the validity and reliability of the personality measurement tool for nursing college students. Methods: Questionnaires were issued to 300 nursing students, with 275 eventually collected. The items were confirmed by validity experts. Construct validity was tested using exploratory factor analysis and confirmatory factor analysis. Reliability analysis was tested using Cronbach's ${\alpha}$. Criterion validity was tested by analyzing correlation with the college adjustment scale. Results: Eight factors were confirmed by exploratory factor analysis. Confirmatory factor analysis was used to confirm the model fit (Root-mean-square residual .03; Root-mean-square error of approximation .06; Comparative fit index .92); and convergent validity and discriminant validity were confirmed. In addition, the criterion validity was confirmed through correlation (r=.64, p<.001) with the college adjustment scale. The reliability of this tool was Cronbach's ${\alpha}$ .94. Conclusion: This tool can be used to measure personality in nursing education and can be used to develop and evaluate personality programs.

• Computers and Concrete
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• v.24 no.2
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• pp.95-102
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• 2019

Current article proposes a cheap prototype of an embedded wireless sensor to monitor concrete structures. The prototype can measure temperature and relative humidity concurrently at a controlled through smartphone time interval. It implements a maturity method to estimate in-place concrete strength, which is considered as an alternative for traditional shock impulse method and compression tests used in Kazakhstan. The prototype was tested and adequately performed in the laboratory and field conditions. Tests aimed to study the effect of internal and ambient temperature and relative humidity on the concrete strength gain. According to test results revealed that all parameters influence the strength gain to some extent. For a better understanding of how strongly parameters influence the strength as well as each other, proposed a multicolored cross-correlation matrix technique. The technique is based on the determination coefficients. It is able to show the value of significance of correlation, its positivity or negativity, as well as the degree of inter-influence of parameters. The prototype testing also recognized the inconvenience of Bluetooth control due to weakness of signal and inability to access several prototypes simultaneously. Therefore, further improvement of the prototype presume to include the replacement of Bluetooth by Narrow Band IoT standard.

• Journal of International Academy of Physical Therapy Research
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• v.10 no.3
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• pp.1856-1861
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• 2019

Background: Although there are interventions available for the improvement of arm functions of patients with stroke, measuring changes in global synkinesis (GS) according to changes in the muscle activity of paretic and nonparetic side muscles is an important factor and studies to investigate such potential factors are evaluated necessary. Objective: To examine the correlation between the affected arm muscle activity and GS changes in patients with stroke. Design: Randomized controlled trial Methods: In order to measure muscle activities of 30 stroke patients, anterior deltoid, posterior deltoid, biceps brachii and triceps brachii of the affected arms were measured using surface electromyography (EMG) and for analyzing GS, biceps brachii and triceps brachi of the affected arms were measured using the same instrument. Results: When the correlations between the muscle activity and GS of the affected arm were analyzed, the results showed significant correlations between the posterior deltoid and the triceps brachii(p < .01) and between the triceps brachii and GS(p < .05). Conclusion: : The results of this study suggest that the efficient movements of the affected arms of stroke patients, it is possible to increase extensor activity by improving smooth antagonism of the arm.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.26 no.2
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• pp.11-18
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• 2020

Background: The purpose of this study is to examine the correlation between high heels and body imbalance among female college students in their twenties who mainly wear high heels and prevent associated problems. Methods: The subjects included 89 female college students in their twenties. They were measured in plantar pressure with a gait analyzer. Their legs were measured in length with a tape measure. Their pain intensity and pain frequency were measured in visual analog scale and in pain rating score. Results: There were statistically positive correlations between right leg length and low back pain frequency (p<.05) and negative correlations between the left hindfoot and low back pain frequency (p<.05). There were statistically positive correlations between right leg length and knee pain frequency (p<.05) and positive correlations between the ankle pain intensity and right leg length (p<.05). Conclusion: The stronger the pain was in the ankle, the stronger and more frequent their lumber pain was. When the pressure of the left heel was lower, the frequency of lumbar pain increased.

• Bulletin of the Korean Chemical Society
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• v.12 no.2
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• pp.193-196
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• 1991

The $^{13}C-NMR$ shifts of a series of para-substituted $8-aryl-tricyclo[3.2.1.0^{2,7}]oct-8-yl$ and $9-aryl-tricyclo[3.3.1.0^{2,8}]-non-9-yl$ cations were measured in $FSO_3H/SO_2ClF\ at\-90^{\circ}$ in order to examine whether the ${\rho}^{C^+}$ values can be used as a measure of the geometric influence on the charge delocalization resulting from ${\rho}$ conjugation in rigid tricyclopropylcarbinyl cations. Plot of the ${\Delta}{\delta}^{C+} shifts against the ${\sigma}^{C+}$ constants revealed excellent linear correlation. The 8-aryl tricyclooctyl systems yielded a ${\rho}^{C+}$ value of -5.00 with r = 0.9962. Previous investigation of the 9-aryl-tricyclononyl systems gave a correlation coefficient of r = 0.9948 with a slope of ${\rho}^{C+}$ = -4.95. A fair parallelism exists between the results of $^{19}F-NMR $ studies and the change of ${\rho}^{C+}$ value in these cations. Consequently, it is established that the ${\rho}^{C+}$ value can be used to explain the mechanism of charge stabilization of the rigid cyclopropylcarbinyl cation such as tricyclo $[3.2.1.0^{2,7}]oct-8-yl$ cation.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1343-1354
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• 2022

Experiments were performed to measure the critical heat flux (CHF) on a vertical surface abutting a coarse packed bed of spherical particles. This geometry is representative of a CANDU reactor calandria tubesheet facing the end shield cavity during the in-vessel retention (IVR) phase of a severe accident. Deionized light water was used as the working fluid. Low carbon steel shielding balls with diameters ranging from 6.4 to 12.7 mm were used, allowing for the development of an empirical correlation of CHF as a function of shielding ball diameter. Previously published data is used to develop a more comprehensive empirical correlation accounting for the impacts of both shielding ball diameter and heating surface height. Tests using borosilicate shielding balls demonstrated that the dependence of CHF on shielding ball thermal conductivity is insignificant. The deposition of iron oxide particles transported from shielding balls to the heating surface is verified to increase CHF non-trivially. The results presented in this paper improve the state of the knowledge base permitting quantitative prediction of CHF in the CANDU end shield, refining our ability to assess the feasibility of IVR. The findings clarify the mechanisms governing CHF in this scenario, permitting identification of potential future research directions.

• The Journal of Korean Physical Therapy
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• v.34 no.5
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• pp.234-241
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• 2022

Purpose: The Cardiac Rehabilitation scale (INCR scale) is a verified measure worldwide. The scale measures the extent to which cardiac rehabilitation meets the various needs of the participating patients and determines how education related to heart disease and rehabilitation satisfies their preferences. The current study applied the INCR scale to verify and develop it for use in Korea by conforming to Korean culture and language. Methods: The Korean version of the INCR scale was created after a six-step process in accordance with the international questionnaire translation law. The Korean version of the INCR scale was assessed in 45 cardiac rehabilitation patients (29 males, 16 females). Internal consistency was verified using Cronbach's alpha. Test-re-test reliability and interrater reliability were verified using the intraclass correlation coefficient (ICC). Content validity was selected to verify the validity. Results: The content validity index of the Korean version of the INCR scale was high, with an average of 0.93. Cronbach's Alpha for Internal consistency also revealed high reliability of 0.89 in all 10 categories. The interclass correlation coefficient of the test-re-test and interrater reliability scores were 0.95 and 0.81, respectively. Conclusion: Our results indicate that the Korean version of the INCR scale would be instrumental in the clinical setting to determine the knowledge, educational needs, and preferences of patients participating in cardiovascular disease and cardiac rehabilitation.

• Journal of the Korean Society of Safety
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• v.37 no.5
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• pp.7-13
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• 2022

Digital image correlation (DIC) is a method used to measure the displacement and strain of structures. It involves transforming and analyzing images before and after deformation using correlation coefficients from irregular light and shade on the surface of structures. In the present study, a microspeckle pattern was applied to the surface of a specimen to identify initial cracking. The test specimen constituted CFRP composites laminated on a curved Al liner The specimen was manufactured by stacking 100 ply of CFRP prepregs in the 0° and 90° directions in a three-point bending test. The equivalent strain was evaluated through DIC analysis after monitoring deformation using a CCD camera. Fracture shape was observed using a microscope. The equivalent strain contour distribution was checked until the maximum load fracture occurred at the center of the test specimen. Variations in the strain indicated the initial occurrence and progression of microcracks. These results can be used to improve the accuracy of detecting micro crack initiation and to achieve structural stability.