• Journal of International Society for Simulation Surgery
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• v.2 no.2
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• pp.80-82
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• 2015

The mandibuloplasty for the facial aesthetic reason has been the one of the most popular procedures in aesthetic facial bone surgery in East Asia. Most East Asian women prefer smaller-looking and smooth-shaped facial contour. Prominent mandible angle which are common in Asia would be the main problem for smooth facial contour. In addition, recently, the mandibular body and broad chin shape also are known to be remodeled in order to get the ideal smooth facial shape. However, mandibuloplasty is not that easy to cut because many patients has inward mandibular angle and the visual field in operation is limited. The aim of this trial is to try to provide the prefabricated cutting guide for the symmetric and appropriate mandibuloplasty with the surgeons. Preoperative computed tomography(CT) data were processed for the patient and computer simulation model was produced. Then, mandibuloplasty was done on the computer simulation screen. Based on this data, customized cutting guide was made. This prefabricated cutting guide was used in real mandibuloplasty bilaterally. Premade cutting guide for the mandibuloplasty based on the computer simulation turned out to be very successful in this patient. Individualized approach for each patient could be an ideal way to manage the patients in near future.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.445-448
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• 2006

The effects of surface roughness on a spatially-developing turbulent boundary layer (TBL) were investigated by performing direct numerical simulations of TBLs over rough and smooth walls. The Reynolds number based on the momentum thickness was varied in the range $Re_{\theta}=300{\sim}1400$. The roughness elements used were periodically arranged two-dimensional spanwise rods, and the roughness height was $k=1.5{\theta}_{in}$, which corresponds to $k/{\delta}=0.045{\sim}0.125$. To avoid generating a rough wall inflow, which is prohibitively difficult, a step change from smooth to rough was placed $80{\theta}_{in}$ downstream from the inlet. The spatially-developing characteristics of the rough-wall TBL were examined. Along the streamwise direction, the friction velocity approached a constant value and a self-preserving form of the turbulent stress was obtained. Introduction of the roughness elements affected the turbulent stress not only in the roughness sublayer but also in the outer layer. Despite the roughness-induced increase of the turbulent stress in the outer layer, the roughness had only a relatively small effect on the anisotropic Reynolds stress tensor in the outer layer. Inspection of the triple products of the velocity fluctuations revealed that introducing the roughness elements onto the smooth wall had a marked effect on vertical turbulent transport across the whole TBL. By contrast, good surface similarity in the outer layer was obtained for the third-order moments of the velocity fluctuations.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2089-2094
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• 2003

The flow around a circular cylinder was controlled by attaching O-rings to reduce drag force acting on the cylinder. Four experimental models were tested in this study; one smooth cylinder of diameter D (D=60mm) and three cylinders fitted with O-rings of diameters d=0.0167D, 0.05D and 0.067D with pitches of PPD=1D, 0.5D and 0.25D. The drag force, mean velocity and turbulent intensity profiles in the near wake behind the cylinders were measured for Reynolds numbers based on the cylinder diameter in the range of $Re_D=7.8{\times}10^3{\sim}1.2{\times}10^5$. At $Re_D=1.2{\times}10^5$, the cylinder fitted with O-rings of d=0.0167D in a pitch interval of 0.25D shows the maximum drag reduction of about 5.4%, compared with the smooth cylinder. The drag reduction effect of O-rings of d=0.067D is not so high. For O-ring circulars, as the Reynolds number increases, the peak location of turbulence intensity shifts downstream and the peak magnitude is decreased. Flow field around the cylinders was visualized using a smoke-wire technique to see the flow structure qualitatively. The size of vortices and vortex formation region formed behind the O-ring cylinders are smaller, compared with the smooth cylinder.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.974-979
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• 2009

Proliferation of vascular smooth muscle cell(VSMC) is one of the key features in onset of atherosclerosis and restenosis after vascular surgery such as stent implant. Atherosclerotic plaques are usually composed of collagen, elatsin and smooth muscle cells. Release of matrix metalloproteinases(MMPs) is considered to have correlation with development of atherosclerotic plaques. Based on the hypothesis that MMP inhibition would be helpful in the treatment of atherosclerosis, we investigated inhibition of MMP activity and migration of TNF-$\alpha$-induced human aortic smooth muscle cell(HASMC) by Cinnamomi Ramulus(CC). The result from gelatin zymography showed that CC inhibited MMP-9 activity in a dose-dependent manner. In addition, CC considerably inhibited the migration of HASMC induced by TNF-$\alpha$, while it showed little cytotoxic effect on HASMC. These results suggest that CC can be a potential anti-atherosclerotic agent through inhibition of MMP-9 activity and SMC migration.

• Journal of Mechanical Science and Technology
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• v.15 no.8
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• pp.1156-1164
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• 2001

Evaporation heat transfer coefficients and pressure drops were measured for smooth and micro-fin tubes with R-22 and R-410A. Heat transfer measurements were performed for 3.0m long horizontal tubes with nominal outside diameters of 9.52 and 7.0mm over an evaporating temperature range of -15 to 5$\^{C}$, a mass flux range of 68 to 211kg/㎡s, and a heat flux range of 5 to 15kW/㎡. It was observed that the heat transfer coefficient increased with mass flux. Evaporation heat transfer coefficients of R-22 and R-410A increased as the evaporating temperature dropped at a lower heat flux. Generally, R-420A showed the higher heat transfer coefficients than R-22 in the range of low mass flux, high heat flux and high evaporating temperature. Pressure drop increased with a decrease of evaporating temperature and a rise of mass flux. Pressure drop of R-22 was higher than that of R-410A at the same mass flux.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1454-1457
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• 2003

This study was carried out to minimize the lifting force of a two hinge type stand mechanism. This unit is designed for the display devices in order to enhance the ergonomics for effective height adjustment and maintenance at any preferred position. The unit will be very useful for the mechanism fabricated with a coil spring and disc springs as a torque generator. The maximum and the minimum torque value should be calculated initially for the smooth lift. And the reasonable torque distribution is necessary to prevent any AUTO LIFT and AUTO Drooping at any position because the torque generated by coil spring is more sensitive than disc spring in tilting the position. Therefore, the analysis of the coil spring is requisite to issue the specific torque value depending on the distorted angle with securing reliability of a long time storage condition. After the theoretical torque value was calculated, the evaluation was carried out by making a proto-type sample, then distorted angle was updated by experiment. The result of this study can readily be applied to various units for the optimization of the smooth lift.

• Korean Journal of Pharmacognosy
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• v.17 no.1
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• pp.12-18
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• 1986

In order to investigate experimentally the clinical effects of Choweesungchung-Tang that has been widely used in the cardiovascular and neuropsychogenic disease, experimental studies with experimental animals were carried out. The results of these studies were summarized as follows; Suppressive action was not shown on the convulsion induced by strychnine, but significant effect was noted on the convulsion induced by picrotoxin and caffeine. In acetic acid method, analgesic effect was noted. By the rotor rod and wheel cage method, sedative action was noted. A prolongation of hypnotic time induced by pentobarbital-Na was obtained. Relaxing action was noted remarkably on the ileum of mice, also about mice and guinea-pigs, the same effect was recognized on the smooth muscle of the ileum. The expansion of blood vessels by relaxation of smooth muscle and hypotensive action were noted.

• International Journal of Air-Conditioning and Refrigeration
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• v.11 no.3
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• pp.114-124
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• 2003

In this study, condensation heat transfer tests were conducted in flat aluminum multi-channel tubes using R-410A, and the results are compared with those of R-22. The flat tubes have two internal geometries; one with smooth inner surface and the other with micro-fins. Data are presented for the following range of variables; vapor Quality (0.1∼0.9), mass flux (200∼600 kg/$m^2$s) and heat flux (5∼15 kW/$m^2$). Results show that the effect of surface tension drainage on the fin surface is more pronounced for R-22 than R-410A. The smaller Weber number of R-22 may be responsible. For the smooth tube, the heat transfer coefficient of R-410A is slightly larger than that of R-22. For the micro-fin tube, however, the trend is reversed. Possible reason is provided considering physical properties of the refrigerants. For the smooth tube, Webb's correlation predicts the data reasonably well. For the micro-fin tube, the Yang and Webb model was modified to correlate the present data. The modified model adequately predicts the data.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.7
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• pp.43-50
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• 2002

This paper presents the new gait implementation of a biped robot with smooth walking using 3-dimensional continuous trunk motion and kick action of ankle joints. Trajectory generation ova trunk is performed not on a unit gait but on a whole walking interval. In applying kick action such as heel-touch or toe-off, varying coordinate system was employed for the simplification of the kinematic analysis. Desired ZMP (zero moment point) is also changed to implement the efficient kick action. As a result, balancing motion of the proposed gait was much more decreased than that of conventional one. Moreover, robot\\`s walking behavior is very smooth, natural and similar to the pace of a human. The walking experiment system is composed of eight AC servo motors and a DSP controller. The walking simulation and the experimental results are shown using the proposed new walking algorithm.

• Korean Journal of Veterinary Service
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• v.17 no.3
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• pp.255-263
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• 1994

To elucidate the action of the adrenergic nerve on the isolated uterine smooth muscle of the pig, effects of electrical transmural nerve stimulation and norepinephrine were investigated on the pretreatment of phentolamine ； non-selective ${\alpha}$-adrenoceptor blocker, propranolol ; ${\beta}$-adrenoceptor blocker and the yohimbine；${\alpha}_2$-selective adrenoceptor blocker from physiograph. 1. The relaxation response induced by norepinephrine was the concentration of $10^{-6}$ M at first and maximum response was concentration of $10^{-4}$M. 2. The relaxation response induced by norepinephrine was not effected by the pretreatment with non-selective $\alpha$-adrenoceptor blocker, phentolanune ($10^{-6}$ M) but was completely blocked by the pretreatment with ${\beta}$-adrenoceptor blocker, propranolol($10^{-6}$ M). 3. The contractile response induced by electrical transmural nerve stimulation(20V, 10Hz, 0.5msec, 20sec ) was inhibited by the pretreatment with non-selective ${\alpha}$-adrenoceptor blocker, phentolamine($10^{-6}$ M) but was not inhibited and rather increased by the pretreatment ${\beta}$-adrenoceptor blocker, propranolol($10^{-6}$ M), and was not approximately effected by the pretreatment with ${\alpha}_2$-adrenoceptor blocker, yohimbine($10^{-6}$ M). These finding suggest that it was excitatory action by ${\alpha}_1$-adrenergic nerve and inhibitory action by ${\alpha}_2$-adrenergic, ${\beta}$-adrenergic nerve on uterine smooth muscle of the pig.