• Earthquakes and Structures
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• v.7 no.4
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• pp.587-607
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• 2014

Progressive collapse, which is referred to as the collapse of the entire building under local damages, is a common failure mode happened by earthquakes. The collapse process highly depends on the whole structural system. Since, asymmetry of the building plan leads to the local damage concentration; it may intensify the progressive collapse mechanism of asymmetric buildings. In this research the progressive collapse of regular and irregular 6-story RC ordinary moment resisting frame buildings are studied in the presence of the earthquake loads. Collapse process and collapse propagation are investigated using nonlinear time history analyses (NLTHA) in buildings with 5%, 15% and 25% mass asymmetry with respect to the number of collapsed hinges and story drifts criteria. Results show that increasing the value of mass eccentricity makes the asymmetric buildings become unstable earlier and in the early stages with lower number of the collapsed hinges. So, with increasing the mass eccentricity in building, instability and collapse of the entire building occurs earlier, with lower potential of the progressive collapse. It is also demonstrated that with increasing the mass asymmetry the decreasing trend of the number of collapsed beam and column hinges is approximately similar to the decreasing trend in the average story drifts of the mass centers and stiff edges. So, as an alternative to a much difficult-to-calculate local response parameter of the number of collapsed hinges, the story drift, as a global response parameter, measures the potential of progressive collapse more easily.

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.251-256
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• 1992

Regional cerebral blood flow were measured in 10 patients with Parkinson's disease and 12 normal persons using $^{99m}Tc-HMPAO$ SPECT. Reconstructed images were interpreted qualitatively and were compared with those findings of CT. For the quantitative analysis, six pairs of region of interest matched with the perfusion territories of large cerebral arteries and cerebellar hemisphere were determined. From the count values, indices showing the degree of asymmetry between right and left cerebral or cerebellar hemisphere, cerebral asymmetry index (ASI) and percent index of cerebellar asymmetry (PIA), and an index showing change of each region, region to cerebellum ratio (RCR) were obtained. ASI of normal persons and patients were $0.082{\pm}0.033$ and $0.108{\pm}0.062$, respectively and PIA were $-0.4{\pm}0.7%$ and $-0.7{\pm}1.0%$, respectively, which showed no statistically significant difference between normal persons and patients. Among 10 RCR's, those of both regions of basal ganglia and both regions of anterior cerebral artery were significantly reduced. We concluded that the most significant reduction of regional cerebral blood flow in patients with Parkinson's disease was observed in the regions of basal ganglia and in the regions of anterior cerebral artery, and the degree of change in hemispheric blood flow was similar in both hemisphere.

• Applied Microscopy
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• v.46 no.1
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• pp.27-31
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• 2016

It has been investigated what kind of characteristic X-ray in electron probe micro-analyzer (EPMA) is effective for the determination of compounds of Si series materials. After comparing the characteristic X-rays among the primary and secondary lines in $K_{\alpha}$ and $K_{\beta}$ obtained from the Si series standard samples, it was found that the secondary line of $K_{\alpha}$ exhibited the most informative spectrum although the intensity was considerably weak. As a result of analyzing the spectrum shapes of the Si series standard samples, the spectrum shape of the secondary line of $K_{\alpha}$ for SiC was different from those for other Si compounds. To grasp the characteristics of the shape, a line was perpendicularly drawn from the peak top to base line in order to divide a spectrum into two areas. The area ratio of right to left was defined to call as the asymmetry index here. As a result, the asymmetry index value of the SiC was greater than one, while those of other Si compounds were less than one. It was found from the EPMA analysis that identification of SiC became successful to distinguish from other Si compounds and this method was applicable for micro-sized compounds in a practical composite material.

• Physical Therapy Korea
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• v.27 no.1
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• pp.70-77
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• 2020

Background: Neck pain can be caused by any structure in the neck, such as intervertebral discs, ligaments, muscles, facet joints, dura mater, and nerve roots. The hyoid bone is a structure that is also related to head and neck posture, neck movement and pain, but there are no studies on hyoid deviation, neck pain, and range of motion (ROM). Objects: The purpose of this study was to investigate the effect of fascia relaxation and mobilization of the hyoid bone on the ROM, pain, and lateral deviation of the hyoid bone. Methods: Twenty-five patients with neck pain identified by the lateral motion test (10 males [35.13 ± 7.67 years, 172.69 ± 3.90 cm, 78.77 ± 6.96 kg] and 15 females [35.13 ± 10.05 years, 161.11 ± 4.09 cm, 52.59 ± 2.98 kg]) was chosen randomly. Baseline values for pain, neck ROM, and lateral deviation in the hyoid bone were recorded using a visual analogue scale (VAS), goniometer, and tape measure. Then, each patient was treated with hyoid fascia relaxation and mobilization, and all results were recorded after intervention. Comparison of the results before and after intervention was analyzed using paird t-test (p < 0.05). Results: Right rotation, extension, VAS, and rotational asymmetry statistically significant differences (p < 0.05). Right rotation and extension increased ROM, rotational asymmetry ratio and VAS decreased. However, there was no significant difference in flexion, left rotation, center point (p > 0.05). Conclusion: Fascia relaxation and hyoid mobilization could improve the ROM of cervical extension, asymmetry of the cervical rotation and neck pain.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.3
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• pp.279-284
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• 2014

PURPOSE: This study intended to verify whether there was actual correlation between weight-bearing asymmetry and a limitation in hip joint rotation range in patients with low back pain. METHODS: Thirty five low back pain patients voluntarily participated this study. For each participant, hip joint medial rotation symmetry rate and the weight-bearing symmetry rate were calculated. The correlation between the two variables was investigated. RESULTS: A decrease in the left hip joint medial rotation range of motion (ROM) was observed more often than a reduction in the right hip joint medial rotation ROM. However, similar number between right and left side was observed in ground reaction force more weighted. The coefficient between the passive hip joint medial rotation symmetry rate and the weight loading symmetry ratio was -0.19 (p < 0.05). CONCLUSION: The present study demonstrated a weak correlation between the hip joint medial rotation ROM and the weight distribution of both feet. Such result suggests that careful evaluation by separating each element is needed in treating patients with low back pain. Future research should take into account asymmetric alignment and abnormal movement in different joints of the body as well as asymmetry in the bilateral hip joint rotation and the unilateral weight supporting posture.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.2
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• pp.15-24
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• 2019

This study analyzes the effect of the capital structure of Korean manufacturing firms on default risk based on Moody's KMV option pricing model where the probability of default is obtained by measuring the distance to default as a covariant in logit model developed by Merton (1974). Based on the panel data of manufacturing firms, this study achieves its primary objective, using a fixed effect regression model and examines the effect of a firm's capital structure on default risk amongst publicly listed firms on Korea exchange during 2005-2016. Empirical results obtained suggest that the rise in short-term debt to assets leads to increase the risk of default whereas the increase in long-term debt to assets leads to decrease the default risk. The benefits of short-term debt financing over a short-term period fade out in the presence of information asymmetry. However, long-term debt financing overcomes the information asymmetry and enjoys the paybacks of tax advantage associated with long-term debt. Additionally, size, tangibility and interest coverage ratio are also the important determinants of default risk. Findings support the trade-off theory of capital structure and recommend the optimal use of long-term debt in a firm's capital structure.

• Journal of Astronomy and Space Sciences
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• v.26 no.1
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• pp.1-8
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• 2009

We present new B, V, and R CCD photometric light curves for the low mass ratio contact binary FP Boo. A new photometric solution and absolute physical dimensions of the system were derived by applying the Wilson-Devinney program to our observed light curves and to previously published Rucinski et al.'s radial velocity curves. From the H-R diagram of 24 low mass ratio contact binary system including FP Boo, the evolutionary stage of FP Boo was found to coincide with those of the general low mass ratio contact binary systems. The light curves obtained in this season show a small asymmetry in their shapes.

• International Journal of Contents
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• v.5 no.1
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• pp.37-45
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• 2009

This paper empirically tests pecking order theory. Korean listed firms are used as the samples. On the whole we find supportive results for pecking order theory. The fixed effect model on the whole period shows that as pecking order theory suggests that debt ratio decreases as cash flow. ROA, physical assets, and firm size increase. Again, it is shown that corporate debt ratio significantly decreases as cash flow or ROA increases in every sub-sample, which coincides with the prediction of pecking order theory. Corporate debt ratio significantly decreases as physical assets or jinn size increases in case of the whole sample, pre-financial crisis period, and the sub-samples by q-ratio, which also supports the prediction of pecking order theory. Statistical significance of the coefficients of physical assets or firm size completely disappears after Korean financial crisis. Perhaps it is because the role of physical assets or firm size as a mitigator of information asymmetry significantly weakens after the financial crisis as Korean financial market becomes more transparent. For small firms only size variable is negatively and significantly related with debt to assets. It seems that size is an important factor for smaller firms in making financing decision.

• Journal of ILASS-Korea
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• v.27 no.1
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• pp.1-10
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• 2022

In this study, an experimental investigation on the effects of the pressure ratio on the wall-impingement spray characteristics of nitrogen gas using a compressed natural gas (CNG) injector was conducted. The transient development of the impingement spray was recorded by a high speed camera with Z-type Schlieren visualization method. The spray behavior under various pressure ratio conditions were analyzed. The experimental results showed that the pressure ratio has positive effect on the development of spray wall-impingement. The effects of the above factor were evaluated in a constant volume chamber at atmospheric conditions. The data from test showed that, with the increase of the pressure ratio, the spray tip penetration (STP) quickly increases before the impingement and gradually increases after the impingement. Additionally, the spray velocity first increases and then sharply decreases on regardless of the injection pressure level. As the spray spreading angle increases, spray area and volume increases rapidly with the increase in STP at the beginning of injection, and finally entered a stable range, has a great correlation with the increase of pressure ratios.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.4
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• pp.587-596
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• 2010

Purpose : This study was performed to investigate the effects of somatosensory training on the spatiotemporal gait parameters and balance in patients with stroke patients. Methods : 24 stroke survivors were allocated in this study, and randomly divided into experimental(n=12) and control group(n=12), independently. Experimental group was applied somatosensory training program plus conventional physical therapy, and control group was applied only conventional physical therapy. All subjects were administered for 30 minutes per day during 8 weeks(5 times a week). Results : Spatiotemporal parameters of gait were significant difference between pre and post intervention in experimental group, except of step length asymmetry ratio(SLAR) and single support time asymmetry ratio (SSAR)(p<.05). But control group had no statistical significance(p>.05). And also there was significant difference between experimental and control group(p<.05), except of cadence and SSAR(p>.05). Balance parameters were significant difference between pre and post intervention in experimental group(p<.05). But control group had no statistical significance(p>.05). And experimental timed up and go test was significantly decreased than control group(p<.05), but berg balance scale and functional reach test were not significant difference between experimental and control group(p>.05). Conclusion : This study was suggested that somatosensory training has effectiveness on the spatiotemporal gait parameters and balance in patients with stroke survivors. So this therapeutic intervention will be effectivelyapply to the stroke survivors in the clinical setting.