• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.863-864
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• 2011

• Physical Therapy Korea
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• v.26 no.1
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• pp.28-36
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• 2019

Background: Temporomandibular disorder (TMD) is characterized by pain and limited range of motion in the jaw. TMD patients generally prefer to chew on the unaffected or less-affected side, and this tendency often results in asymmetries in masseter muscle thickness and range of mandibular motion. Objects: The purpose of this study was to compare the asymmetries in masseter muscle thickness and range of mandibular motion in subjects with and without temporomandibular disorders. Methods: Thirty-nine subjects were divided into two groups: A TMD group ($n_1=19$) and a control group ($n_2=20$). The jaw opening range and laterotrusion were measured using a digital vernier caliper. The masseter muscle thickness was examined in both the resting state and the maximal clenching state using ultrasonography. The absolute asymmetry indices calculated based on the laterotrusion and masseter muscle thickness of the respective right and left sides. A two-way ANOVA and a Mann-Whitney U test were used for statistical analysis. Results: No significant different was found in the masseter muscle thickness between the TMD and control group. A significant difference was found in the absolute asymmetry indices of mandibular laterotrusion between the TMD and control groups (p<.05). Furthermore, the ranges of jaw opening were significantly different between males and females (p<.05). The absolute asymmetry index values of masseter muscle thickness at rest and during maximal clenching were also significantly different between males and females (p<.05). Conclusion: These results demonstrated that the subjects with TMD had a larger degree of asymmetry in laterotrusion than those without TMD. Therefore, a physiotherapy program needs to be designed to restore normal laterotrusion capacities for TMD subjects. These results also showed that female subjects had greater absolute asymmetry indices in masseter muscle thickness than male subjects. Therefore, more training is needed to promote bilaterally balanced chewing among women.

• Imaging Science in Dentistry
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• v.34 no.1
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• pp.13-18
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• 2004

Purpose : This study was to evaluate the influence of slice thickness of computed tomography (CT) and rapid protyping (RP) type on the accuracy of 3-dimensional medical model. Materials and Methods: Transaxial CT data of human dry skull were taken from multi-detector spiral CT. Slice thickness were 1, 2, 3 and 4 mm respectively. Three-dimensional image model reconstruction using 3-D visualization medical software (V-works /sup TM/ 3.0) and RP model fabrications were followed. 2-RP models were 3D printing (Z402, Z Corp., Burlington, USA) and Stereolithographic Apparatus model. Linear measurements of anatomical landmarks on dry skull, 3-D image model, and 2-RP models were done and compared according to slice thickness and RP model type. Results: There were relative error percentage in absolute value of 0.97, 1.98,3.83 between linear measurements of dry skull and image models of 1, 2, 3 mm slice thickness respectively. There was relative error percentage in absolute value of 0.79 between linear measurements of dry skull and SLA model. There was relative error difference in absolute value of 2.52 between linear measurements of dry skull and 3D printing model. Conclusion: These results indicated that 3-dimensional image model of thin slice thickness and stereolithographic RP model showed relative high accuracy.

• Physical Therapy Korea
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• v.18 no.3
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• pp.8-15
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• 2011

Abdominal muscle plays a crucial role in postural control and respiration control. However, thickness of abdominal muscle in the paretic side of a hemiplegic patient has not been reported in previous studies. The purpose of this research was to compare lateral abdominal muscle thickness between the nonparetic and paretic side in patients with chronic stroke using rehabilitative ultrasound imaging. Twenty two patients with chronic stroke participated in this study. Absolute thickness of transversus abdominis (TrA), internal oblique (IO) and external oblique (EO) was measured at the end of inspiration and expiration during quiet breathing, and relative thickness was calculated (thickness of each muscle as a percentage of total muscle thickness). Ultrasound imaging was recorded three times and the average value was determined for statistical analysis. Differences in absolute and relative lateral abdominal muscle thickness between the nonparetic and paretic side were assessed with paired t-tests. Absolute muscle thickness of the paretic side TrA was thinner than that of the nonparetic side at the end of inspiration and expiration during quiet breathing. Relative muscle thickness of the paretic side TrA was thinner than the paretic side only at the end of expiration during quiet breathing (p>.05). Therefore, it is necessary to strength TrA in patients with chronic stroke during physical therapy intervention. Further study is needed whether physical therapy intervension will induce TrA thickness in patients with chronic stroke in prospective study design.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.249-250
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• 2009

• Journal of Mechanical Science and Technology
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• v.14 no.7
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• pp.737-743
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• 2000

This paper presents the effects of circumferential groove on the minimum oil film thickness in engine bearings. The fluid film pressures are calculated by using the infinitely short bearing theory for the convenience of analysis. Journal locus analysis is performed by using the mobility method. A comparison of minimum oil film thickness of grooved and ungrooved bearing is presented. It is found that circumferential $360^{\circ}$ groove only reduces the absolute magnitude of the oil film thickness, but $180^{\circ}$ half groove affects the shape of film thickness curve and position of minimum oil film thickness.

• The Korea Journal of Herbology
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• v.20 no.4
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• pp.83-94
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• 2005

Objectives : The present study attempted to reveal the effects of Morindae Radix extracts on the sciatic nerve neurectomized osteoporotic ddy mice model. Methods : Thickness of hind limbs and their differences, absolute and relative tibia weight and thickness, bone failure load, bone mineral density (BMD), histomorphometrical index, serum osteocalcin level, tibia calcium and phosphorus contents were monitored. Results : In sciatic neurectomized mice, thickness of hind limb, absolute and relative weights, thickness, failure loads, BMD of tibia, trabecular bone volume (TBV), thickness of trabecular bone and cortical bone thickness, length were significantly decreased. However, these changes of those dose-dependently reduced in MR extract-dosing group. Conclusions : it is considered that MR extracts have some favorable effect to prevent, the osteoporosis induced by sciatic neurectomy. However, the exact mechanism and the possibility of MR extract were remains unknown. In addition, the potential toxicity of these MR extracts were also unknown. So the further studies were needed about toxicological and pharmacological aspects.

• Journal of the Korean Society of Physical Medicine
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• v.7 no.3
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• pp.319-327
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• 2012

Purpose : This study aimed to identify the asymmetry observed in the rehabilitative ultrasound imaging of lateral abdominal muscle thickness and performance between the affected and unaffected side during the abdominal drawing-in maneuver (ADIM), an exercise used to facilitate activation of selectively TrA to stabilize the trunk prior to limb movement. Methods : The Participants were twenty one patients with post-stroke hemiplegia in this study. Ultrasound imaging was used to measure amount of changes in thickness of the external oblique (EO), internal oblique (IO), transversus abdominis (TrA). A Paired t-test was used to compare relaxed muscle thickness to contracted muscle thickness of all 3 muscles between the affected and unaffected sides. Results : The outcome measures included side to side differences of absolute thickness, contraction ratio among the lateral abdominal muscles. There was no significantly difference in between the affected and unaffected side at rest. But, there was a significantly difference in absolute muscle thickness between the affected and unaffected side of only TrA muscle. Also contraction ratio was a significantly difference between the affected and unaffected TrA muscle. Conclusion : These findings support the asymmetrical activation of TrA muscle during abdominal muscle contraction in patients with post-stroke hemiplegia. Further studies are warranted for confirming this outcome.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.3
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• pp.374-380
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• 2003

This paper proposes dimensionless correlations predicting properties of the frost layer formed on a cold flat surface. Experiments are carried out to obtain the correlations with various environmental parameters such as air temperature, air velocity, absolute humidity, and cooling plate temperature. As a result, the frost properties (frost layer thickness, density, surface temperature, thermal conductivity) are correlated as a function of Reynolds number, Fourier number, absolute humidity and non-dimensional temperature by using a dimensional analysis. The correlations agree well with the previous and our experimental data within a maximum error of 10%, and are used to predict the frost properties in the following ranges: Reynolds number of 20216 to 53763, Fourier number of 0.1962 to 2.5128, absolute humidity of 3.22 to 8.47, and non-dimensional temperature of 0.125 to 0.5.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.240-245
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• 2000

In this study, thickness, density and effective thermal conductivity of frost forming on the horizontal cylinder were measured with various air temperature and humidity. Reynolds number and temperature of cooling surface are controlled 17300 and $-l5^{\circ}C$ respectively. In each case of air temperature $5^{\circ}C,\;10^{\circ}C,\;15^{\circ}C,$ varying absolute humidity, experiments were executed. In measuring frost surface temperature and thickness of frost layer, infrared thermocouples and CCD camera were used. Frost was gathered from cylinder to measure mass of frost layer. Experimental data showed that the thickness and effective thermal conductivity of the frost layer increase with respect to time. Thickness of frost layer increase with humidity increasing, and density of frost layer increase with air temperature rising. Frost growth with air temperature and density of frost layer with humidity are affected by whether dew point is below or above freezing point.