• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.5
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• pp.498-504
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• 2014

Displacements and strains are very important for material evaluation as critical factors to a machine's life cycle and safety. Typically, the strain gauge has been employed to measure displacement and strain. However, this contact-type measurement method has disadvantages that are not quantified under the test conditions of a specific object shape, surface roughness, and temperature. In this paper, the measurement of deflection and flexural strain due to the three-point bending test is presented, employing Digital Image Correlation (DIC) methods. In order to ensure measurement reliability, DIC and universal test machine methods were compared by measuring the deflections and flexural strains developed by such bending tests.

• Journal of the Korean Society of Clothing and Textiles
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• v.15 no.4 s.40
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• pp.373-380
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• 1991

In the previous paper, we already discussed about the factor effected upon the initial maximum value of heat flux ($q_{max}$). Thermal conductivity, thermal transmittance and surface air cavity of wool fabrics were examind and their correlation to the $q_{max}$ was also studied In this study, the other factor was examined which had on effect upon the qmaf of an objective measure of warm/cool feeling. It was studied that the qmax correlated to the surface sturucture parameters (compression, friction, smoothness, roughness, thickness and weight). It was concerned to the degree of warm/cool feeling when we touched hand on fabrics. We selected twenty sorts of pure wool woven fabrics for men's fall-winter cloth (all Wool). The conclusions are as follow; 1. There was a good correlation between the $q_{max}$ and the compression property. 2. The surface structure parameters, smoothness and roughness, made various effects on the $q_{max}$, when the samples touched on a thin copper plate. So, there was not a certain correla-tion to the $q_{max}$.

• Journal of Physiology & Pathology in Korean Medicine
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• v.31 no.5
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• pp.294-303
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• 2017

The purpose of this study was to investigate self care, depression, and Yangsaeng and to confirm the factors related to Yangsaeng of diabetes mellitus patients. The survey was conducted on 116 subjects who consented to Institutional Review Board for diabetes mellitus patients in the area and data were collected by self-report questionnaire. The questionnaires consisted of self care, depression, and Yangsaeng. Date analysis was done by SPSS 22.0 with T-test, ANOVA, $Scheff{\acute{e}}$ test, Pearson correlation coefficient, and multiple regression. Yangsaeng was significantly related to the educational level, partner, income, perceived health status, depression, and admission for diabetes mellitus. Yangsaeng and self care showed positive correlation, on the other hand Yangsaeng and depression showed negative correlation. Yangsaeng was found to be related to education level, self care, and depression through the multiple regression. In conclusion, the Yangsaeng score increased with improving of blood glucose level and depression. Based on these results, we considered various characteristics such as patient's age and illness characteristics, therefore it is necessary to develop a method to measure Yangsaeng.

• Journal of International Academy of Physical Therapy Research
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• v.9 no.4
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• pp.1602-1607
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• 2018

This study examined the correlation between power error (PE) and velocity error (VE) according to the condition and frequency of self-controlled feedback (SCF) during knee extension. One hundred participants were randomly assigned to 30% SCF, 70% SCF, 30% yoked feedback (YF), 70% YF and control group, respectively. The SCF group was provided with feedback when they requested it, whereas the YF group did not influence the feedback schedule. Participants in the control group were not given any visual feedback during the experiment. The isotonic, isometric, and isokinetic dynamometer (PRIMUS RS, BTE, USA) was used to measure the power and velocity error during knee extension. The collected data was analyzed using a Pearson test and SPSS 21.0. The correlation between PE and VE according to the condition and frequency of feedback on each phase during knee extension was significant. Both PE and VE were significantly higher when the feedback was provided with high frequency, passive, and no feedback. Our study suggests that application of SCF can help to improve the proprioception of the healthy person while reducing errors through low frequency and active feedback.

• Journal of the Optical Society of Korea
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• v.16 no.4
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• pp.372-380
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• 2012

The optical method Digital Speckle Correlation Measurement (DSCM) has been extensively applied due its capability to measure the entire displacement field over a body surface. A formula of displacement measurement errors by the gradient-based DSCM method was derived. The errors were found to explicitly relate to the image grayscale errors consisting of sub-pixel interpolation algorithm errors, image noise, and subset deformation mismatch at each point of the subset. A power-law dependence of the standard deviation of displacement measurement errors on the subset size was established when the subset deformation was rigid body translation and random image noise was dominant and it was confirmed by both the numerical and experimental results. In a gradient-based algorithm the basic assumption is rigid body translation of the interrogated subsets, however, this is in contradiction to the real circumstances where strains exist. Numerical and experimental results also indicated that, subset shape function mismatch was dominant when the order of the assumed subset shape function was lower than that of the actual subset deformation field and the power-law dependence clearly broke down. The power-law relationship further leads to a simple criterion for choosing a suitable subset size, image quality, sub-pixel algorithm, and subset shape function for DSCM.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.10
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• pp.3771-3792
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• 2021

With the rapid development of science and technology, several high-performance networks have emerged with various new applications. Consequently, financially or socially motivated attacks on specific networks have also steadily become more complicated and sophisticated. To reduce the damage caused by such attacks, administration of network traffic flow in real-time and precise analysis of past attack traffic have become imperative. Although various traffic analysis methods have been studied recently, they continue to suffer from performance limitations and are generally too complicated to apply in existing systems. To address this problem, we propose a method to calculate the correlation between the malicious and normal flows and classify attack traffics based on the corresponding correlation values. In order to evaluate the performance of the proposed method, we conducted several experiments using examples of real malicious traffic and normal traffic. The evaluation was performed with respect to three metrics: recall, precision, and f-measure. The experimental results verified high performance of the proposed method with respect to first two metrics.

• Coupled systems mechanics
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• v.11 no.1
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• pp.15-32
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• 2022

The comprehensive understanding of the fiber reinforced polymer behavior requires the use of advanced non-destructive testing methods due to its heterogeneous microstructure and anisotropic mechanical proprieties. In addition, the material response under load is strongly associated with manufacturing defects (e.g., voids, inclusions, fiber misalignment, debonds, improper cure and delamination). Such imperfections and microstructures induce various damage mechanisms arising at different scales before macrocracks are formed. The origin of damage phenomena can only be fully understood with the access to underlying microstructural features. This makes X-ray Computed Tomography an appropriate imaging tool to capture changes in the bulk of fibrous materials. Moreover, Digital Volume Correlation (DVC) can be used to measure kinematic fields induced by various loading histories. The correlation technique relies on image contrast induced by microstructures. Fibrous composites can be reinforced by different fiber architectures that may lead to poor natural contrast. Hence, a priori analyses need to be performed to assess the corresponding DVC measurement uncertainties. This study aimed to evaluate measurement resolutions of global and regularized DVC for glass fiber reinforced polymers with different fiber architectures. The measurement uncertainties were evaluated with respect to element size and regularization lengths. Even though FE-based DVC could not reach the recommended displacement uncertainty with low spatial resolution, regularized DVC enabled for the use of fine meshes when applying appropriate regularization.

• Journal of Korean Physical Therapy Science
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• v.30 no.3
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• pp.14-22
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• 2023

Background: This study was to investigate the relationship between scapular downward rotation ratio (SDRR), lower trapezius (LT) muscle, and rounded shoulder angle (RSA) on each side in subjects with scapular downward rotation syndrome (SDRS). Design: Cross-sectional Study Methods: Fifteen subjects have participated in this study. The RSA and SDRR were assessed using a tape measure in standing posture. The RSA was computed by the angle made by two lines: one was the distance between the root of the scapula and the acromion, and the other was the distance between the acromion and the horizontal line in the root of the scapula. The SDRR was computed by two horizontal lines: one was the distance between the mid-line and root of the scapula, and the other was the distance between the mid-line and inferior angle of the scapula. LT muscle strength was performed in a prone position by the hand-held dynamometer. Results: There was a positive correlation between SDRR and LT strength in the less affected sides (r=.59; p=.02), however, there was no correlation between RSA and LT strength in the more affected sides (p>.05).

• Journal of The Korean Association For Science Education
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• v.29 no.4
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• pp.388-399
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• 2009

This study was designed to investigate whether applying mind mapping in a biology class had an effect on students' creativity. Participants of this study were 165 1st grade middle school students. The pretest-post test control group design was employed. A control group was instructed with a traditional method and an exerimental group was instructed using the mind-map applied method. The units "Digestion and Circulation" and "Respiration and Excretion" were selected for this study, and each group was treated for 24 class hours. To measure student creativity, the TTCT test was used. For assessing students' level of logical thinking, the compact version of GALT was used. Test results were analyzed by ANCOVA and correlation analysis by SPSS 12.0. The creativity of students in experimental group was significantly improved than the control group (p< .01). Fluency, flexibility, and originality of students in experimental group were improved (p< .01). Students did not show any differences on creativity according to their academic achievement level or gender (p> .05) in the experimental group. Students did not show any differences on creativity according to their logical thinking level (p> .05), either. However, the students of logical thinking level in the experimental group improved their flexibility (p< .05). There was no correlation between students' creativity and their achievement (p> .05), but the creativity shows a lower correlation to performance evaluation (p< .05).

• Physical Therapy Rehabilitation Science
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• v.13 no.3
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• pp.285-293
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• 2024

Objective: This study investigated whether the acromion-table distance is associated with trapezius activity patterns during shoulder movements and the upper quarter Y-balance test (UQYBT). Additionally, it was to determine the correlation between upper, middle, and lower trapezius muscle activity. Design: Cross-sectional study Methods: Twenty-eight healthy young males participated in this study. Outcome measures included: (1) acromion-to-table distance, which assesses the scapular position, (2) trapezius muscle activity during shoulder flexion and abduction, and (3) the UQYBT, a measure of upper extremity function measured. Results: A significant negative correlation was observed between the acromion-table distance and the inferior-lateral direction reach distance of UQYBT (r=-0.499 and p=0.007). There were negative correlations between the upper and lower trapezius during shoulder flexion (r=-0.901, p < 0.001) and abduction (r=-0.661, p < 0.001), respectively. There was also a negative correlation between the upper and middle trapezius during shoulder abduction (r=-0.466, p=0.012). Conclusions: The acromion-table distance was related to the UQYBT. Anterior tilt of the scapula and limited range of motion of the shoulder may occur as the acromion-table distance increases. In addition, the acromion-table distance reflects the pectoralis minor muscle shortening, suggesting that the scapula position or the pectoralis minor shortening may influence the upper limb function. Therefore, these factors should be considered when assessing upper limb function using the UQYBT.