• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.441-442
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• 2002

Chemical mechanical polishing (CMP) is a manufacturing process that uses controlled wear to planarize dielectric and metallic layers on silicon wafers. CMP experiments revealed that a sub-ambient film pressure developed at the wafer/pad interface. Additionally, dishing occurs in CMP processes when the copper-in-trench lines are removed at a rate higher than the barrier layer. In order to study dishing across a stationary wafer during polishing, dishing maps were created. Since dishing is a function of the total contact pressure resulting from the applied load and the fluid pressure, the hydrodynamic pressure model was refined and used in an existing model to study copper dishing. Density maps, highlighting varying levels of dishing across the wafer face at different radial positions, were developed. This work will present the results.

• Archives of Plastic Surgery
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• v.46 no.6
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• pp.511-517
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• 2019

Background Cleft treatment is frequently performed in Indonesia, mostly in charity missions, but without a postoperative protocol it is difficult to establish the risks and complications of cleft treatment. The present study was designed to give an overview of current cleft lip and palate treatment strategies in Indonesia and to assess the complication rates during and after surgery. Methods This prospective study evaluated anesthetic, intraoperative surgical, and short-term postoperative complications in patients undergoing primary, secondary, or corrective surgery for cleft lip and palate deformities. The population consisted of 98 non-syndromic cleft patients. The main anesthetic complication that occurred during general anesthesia was high blood pressure, whereas the main intraoperative surgical complication was excessive bleeding and the main early postoperative complication was extremely poor wound hygiene. Results In this study, there were no cases of perioperative or postoperative mortality. However, in 23 (23.4%) of the 98 operations performed, at least one perioperative complication related to anesthesia occurred. The intraoperative and early postoperative complications following cleft lip and/or palate were assessed. There was a significant difference in the complication rate between procedure types (χ²=0.02; P<0.05). However, no relationship was found between perioperative complications related to anesthesia and the occurrence of postoperative complications (χ²=1.00; P>0.05). Nonetheless, a significant difference was found between procedure types regarding perioperative complications and the occurrence of postoperative complications (χ²=0.031; P<0.05). Conclusions Further evaluation of these outcomes would help direct patient management toward decreasing the complication rate.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.4
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• pp.78-86
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• 2000

The objective of this research is to understand the characteristics of a nonpremixed, turbulent, hydrogen jet flame which is stabilized in Mach 1.8 coflowing air flows. In order to investigate the flame structure, flame lengths and fuel trajectories were measured by using direct photography, acetone PLIF, Mie scattering techniques, and numerical simulation. Effect of increasing air velocity was investigated when fuel velocity is fixed. The subsonic flame length was decreased drastically, however the supersonic flame length was increased slowly Then the change of flame blow out characteristics was observed as varying fuel nozzle lip thickness. The flame stability can be increased when fuel nozzle lip thickness was increased, which indicates that the minimum fuel lip thickness ratio is required for the stable supersonic flames. Also, it is found that fuel jet is blocked by high pressure zone and low scattering zone is made. Then the fuel that was moving along the recirculation zone had longer residence time within the supersonic flames, which made partially premixed zone.

• Phonetics and Speech Sciences
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• v.16 no.3
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• pp.59-69
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• 2024

Among the subgroups of speech sound disorder (SSD), the motor speech disorder (MSD) group is characterized by weak articulatory force. This study quantitatively measured and compared articulatory muscle strength between SSD and typically developing (TD) children. The Iowa Oral Performance Instrument (IOPI) was used to measure lip and tongue strength in 15 children with SSD and 15 TD children. We additionally measured peak lip and tongue pressure and endurance, and analyzed the correlation between each strength measure and the percentage of consonants correct (PCC). The findings were as follows: First, lip strength for the bilabial sounds did not differ between the two groups in the initial position but was significantly weaker in the SSD group in the final position. Tongue strength for alveolar sounds was weaker in the SSD group than in the TD group for the initial and final positions. Second, for lip and tongue strength, the difference in voicing features was significant in the TD group but not in the SSD group. Third, the peak pressure and endurance of the lips and tongue were significantly lower in the SSD group than in the TD group. Fourth, significantly higher static correlations were observed between most strength measures and the PCC. These findings suggest that weakness in articulatory motor execution may be an unrecognized underlying problem of SSD with unknown origin.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1476-1477
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• 2008

This paper reports on a flexible flap valve actuated by electromagnetic force under a constant pressure source. The flexible flap valve consists of the three main components: a flexible flap with a steel disk embedded in PDMS, an electromagnetic actuator and two glass plates with inlet and outlet. Sealing lip structures for improving the valve characteristics are added on the outlet of the bottom glass substrate. The flap valve is fabricated by the spin-coating process, the EDM process, SU-8 mold process and oxygen plasma treatment. The dimension of an assembled flap valve is $12mm{\times}20mm{\times}28mm$. The stroke volume of the flap valve is measured for various pressures and open times. When the input voltage of 30 V is applied for 0.33 s, the minimum stroke volume of the flap valve is 70 ${\mu}L$ at 50 kPa.

• Korean Journal of Cleft Lip And Palate
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• v.8 no.2
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• pp.81-86
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• 2005

Cleft palate patients with congenital anomalies have an increased risk of airway problems following palatoplasty. Factors that were related included presence of associated congenital anomalies, duration of surgery, age at time of surgery, history of previous airway problem, and excessive pressure exerted on the base of the tongue by Dingman retractor. This report described a complication of post-operative Pneumonia after palatoplasty (Furlow technique), which resulted in a life-threatening acute airway obstruction in an infant with cleft palate. Patient has a history of previous mild airway problems. In addition to this problem, we speculate that Furlow technique involves more extensive surgical dissection than other techniques may increase risk for upper airway obstruction. Awareness of this risk permits identifying those patients prior to surgery so that they can be monitored and managed properly, minimizing the likelihood of major complications or possibility of death.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.3
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• pp.20-28
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• 2000

Air wiping technique is widely used because of easy and efficient coating control in present CGL The coating weight is controlled by nozzle header pressure. strip line speed, and the distance between strip and nozzle. Coating defects are resulted from the unbalance of these control factors and the inaccuracy of coating equipments. We investigates the main cause of coating defects, such as edge overcoating and coating deviation through various experiments. It is found that the edge overcoating is mainly come from nozzle lip type, and the coating deviation is caused by the unbalance of dynamic pressure.

• The Journal of the Korean dental association
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• v.15 no.12
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• pp.1027-1030
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• 1977

It has been widely believed that the exact measurement of the forces exerted on teeth and its structures by the lingual and perioral musculatures such as lip, cheek and tongue is important and significant in dentistry. Such measuring, moreover, is highly emphasized the importance of the fact that it can be of much help to study the physiological function displayed in the oral cavity. Recognizing the importance of measuring the pressures, the author has devised an electronic device consisting of pressure transducers utilizing reistance-strnain gauges. This electronic strain gauge was very easy to manipulate and its scale error was extremely minimized, unaffected by mouth temperature, mosture and external forces Author was able to read its results with attached meter without using calibration chart. Futhermore, the sensitivity of this electronic device was extremely high, Thus it facilitated to measure a force from 0 to 230 grams.

• Design & Manufacturing
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• v.14 no.4
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• pp.1-10
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• 2020

The seal plays a role in preventing oil leakage when the lip and the rotating shaft come into contact with the fluid and air pressure. Recently, micro dimples or micro pockets are processed and used on the lubrication surfaces of thrust bearings, mechanical bearings, and piston rings. Compared to a smooth surface, micro dimples reduce friction and increase the life of parts. This paper analyzed various kinds of micro dimple shapes on the sealing surface, i.e. circle, rectangle, triangle, and trapezoid. For this purpose, Introduced the design of experiments to work out a micro dimple configuration, unlikely to be damaged from cracks and low in contact stress. As a result, the triangular dimple showed the best results. Optimal factors were dimple size 0.15 mm, dimple depth 0.0383 mm, dimple density 40%, and the maximum equivalent stress was 9.1455 MPa, and the maximum contact pressure was 9.6612 MPa. This paper analyzed the optimal shape of dimples by finite element analysis. As a research project, experiments and comparative analysis of micro dimple shapes are needed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.10
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• pp.985-991
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• 2010

The objective of this work was to investigate the pintle-tip shape effect on nozzle flow and thrust by cold flow test. When nozzle throat area was decreased by pintle movement, chamber pressure was increased monotonously but thrust was increased differently according to every pintle-tip shape. At the same chamber pressure and nozzle throat area, thrust of convex pintle-tip shape was mostly larger than that of concave one. Nozzle wall pressure distribution and magnitude of pintle-tip load depended on the pintle-tip shape, pintle position and nozzle throat area.