• The Journal of Korean Academy of Prosthodontics
• /
• v.32 no.3
• /
• pp.396-410
• /
• 1994

Ten subjects who were going to wear conventional complete dentures were selected for this study. Theree subjects were women and seven were men. The average age was 63.1 years(range : 44 to 76 years). With the Height tracer (extraoral tracing device) in place the subject was instructed to go through the entire range of mandibular movements. The extreme lateral pathway of the incisor point, the so-called Gothic arch, was thereby inscribed by the stylus on the tracing plate. The mandibular movements in this study were peformed voluntarily by the subject(self guided technique) and guided by the dentist(chin-point technique and bimanual technique). The Gothic arch tracings were analysed and the Gothic arch angles and eccentric movement distances were measured. The results were as follows : 1. The apex position of the Gothic arch tracings of mandibular movements in edentulous patients varied both anterioposteriorly and mediolaterally. 2. The Gothic arch tracing had some lateral deviation during protrusion. 3. The average Gothic arch tracing angle was $136.7{\pm}12.0^{\circ}$ by subjects self guided technique, $135.7{\pm}5.9^{\circ}$ by chin-point technique, $136.6{\pm}6.5^{\circ}$ by bimanual technique. But there were no statistical differences in the reliability among the three techniques. 4. The average mandibular eccentric movements were irregular and the mandibular eccentric movement distances varied with a wide range.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.19 no.4
• /
• pp.190-195
• /
• 2009

Na-tetrasilicic fluorine mica powders were synthesized by skull melting method. The staring materials having chemical composition of $Mg_3(OH)_2Si_4O_{10}:Na_2SiF_6:SiO_2=8.3:24.8:66.9$ mol% were charged into a cold crucible of 13 cm in diameter and 14cm in height and heated by R.F. generator at working frequency of 2.84 MHz. The materials were maintained for 1hr as a molten state and cooled down in the container. In this study, the specific electric resistance of mica was estimated and the columnar and plate shaped mica were synthesized.

• Korean Journal of Cleft Lip And Palate
• /
• v.6 no.2
• /
• pp.59-67
• /
• 2003

A cephalometric study was performed to reveal differences between skeletal Class III malocclusion patients and cleft lip and palate patients, The material for this study consisted of 16 males (mean age 19.8, range 17-29) and 9 females(mean age 19.4, range 16-27) with cleft lip and palate, and 222 Skeletal Class III malocclusion patients(males 106, females 116), Cephalometric tracing and measurements were done by one investigator. Results were followed: 1. Cleft lip and palate group had more retrusive maxilla than the skeletal Class III malocclusion group. 2, Cleft lip and palate group had smaller effective maxillary and mandibular length than skeletal Class III malocclusion group, and the difference was more prominent in the mandible than in the maxilla. 3. Dental compensation was not observed in the upper incisors of cleft lip and palate group and in the lower incisors it was smaller than skeletal Class III group. 4, In the Gonial angle and lower anterior facial height values, there was no significant difference between cleft lip and palate and skeletal Class III malocclusion group. These results can be used in orthodontic treatment planning and orthognathic surgery for the cleft lip and palate patients.

• Nuclear Engineering and Technology
• /
• v.52 no.3
• /
• pp.589-596
• /
• 2020

Many components in the assembly section of Sodium-cooled Fast Reactor are made of good corrosionresistant 316 LN Stainless Steel material. To avoid self-welding of the components with the coolant sodium at elevated temperature, hardfacing is inevitable. Ni-based colmonoy-5 is used for hardfacing due to its lower dose rate by Plasma Transferred Arc process due to its low dilution. Since Ni-Cr-B-Si alloy becomes very fluidic while depositing, the major height of the weld overlay rests inside the groove. Hardfacing is also done over the plain surface where grooving is not possible. Therefore, grooved and ungrooved hardfaced specimens were prepared at different travel speeds. Fe content at every 100 ㎛ of the weld overlay was studied by Energy Dispersive Spectroscopy and also the micro hardness was determined at those locations. A correlation between iron dilution from the base metal and the micro hardness was established. Therefore, if the Fe content of the weld overlay is known, the hardness at that location can be obtained using the correlation and vice-versa. A new correlation between micro hardness and dilution coefficient is obtained at different locations. A comparative study between those specimens is carried out to recommend the optimum travel speed for lower dilution.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.984-999
• /
• 2010

A long-term field demonstration experiment of selected stabilization method to reduce the heavy metal mobility in farmland soil contaminated by heavy metals around abandoned mine site was conducted. Field demonstration experiments were established on the contaminated farmland with the wooden plate(thickness=1cm) which dimension were width=200cm, Length=200cm, height=80cm and filled with treated soil, which was mixed with lime stone and steel refining slag except on control plot. Soil samples in the plots were collected and analyzed during the experiment period(2008. 2~2008. 8) after the installation of the plots. Field demonstration experiments results showed that the application ratio of lime stone 5% was effective for immobilizing heavy metal components in contaminated farmland soil.

• The KSFM Journal of Fluid Machinery
• /
• v.9 no.6 s.39
• /
• pp.54-62
• /
• 2006

An experiment about performance characteristics is conducted on a double chamber vane-type rotor. Three different rotors, which have 6, 8 and 9 vanes, are applied to the driver and various lift holes at the rear plate are used to increase the effective vane height. The inner diameter of a double chamber cylinder is ${\phi}27mm$, and the length of the cylinder is 65 mm. The maximum offset length between the rotor outer surface and the cylinder inner surface is 4.5 mm. In this study, specific output torques and powers are measured, and also noise and vibration are measured at the real operating situation. The operating torque on the double chamber is increased to 17% compared to the operating torque obtained at the single chamber which has the same size. The experimental results of noise and vibration show that the operating sound and vibration are directly related to the operating power generated by the double chamber rotor.

• Journal of Korean Society of Forest Science
• /
• v.82 no.1
• /
• pp.7-11
• /
• 1993

The swollen tissue of wound origin formed after nailing ㄷ-shaped fastener to a stem of Platanus occidentalis L. was compared with normal tissue in the qualitative and quantitative anatomical aspects. The swollen tissue appeared to differ from normal tissue in irregular cell orientation, occurrence of tyloses in vessel element, less common appearance of pore multiples, narrower and shorter vessel element, lower vessel frequency, shorter and highly thick-walled wood fiber, greater number of bars per scalariform perforation plate in vessel element, larger ray frequency, larger ray width and lower ray height.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.23 no.10
• /
• pp.1340-1346
• /
• 1999

The turbulent shear flow around a surface-mounted vertical fence was investigated using the two-frame PTV system. The Reynolds number based on the fence height(H) was 2950. From this study, it is revealed that at least 400 instantaneous velocity field data are required for ensemble average to get reliable turbulence statistics, but only 100 field data are sufficient for the time-averaged mean velocity information. Various turbulence statistics such as turbulent intensities, turbulence kinetic energy and Reynolds shear stress were calculated from 700 instantaneous velocity vector fields. The fence flow has an unsteady recirculation region behind the fence, followed by a slow relaxation to the flat-plate boundary layer flow. The time-averaged reattachment length estimated from the streamline distribution is about 11.2H. There exists a region of negative Reynolds shear stress near the fence top due to the highly convex (stabilizing) streamline-curvature of the upstream flow. The large eddy structure in the separated shear layer seems to have significant influence on the development of the separated shear layer and the reattachment process.

• Proceedings of the KSME Conference
• /
• 2002.08a
• /
• pp.811-814
• /
• 2002

Using a mathematical theory, we show that the optimality condition of a turbulent diffuser with maximum pressure recovery at the exit is zero shear stress along the wall. The optimal diffuser shape is designed through iterative procedures by using the $k-{\varepsilon}-{\nu}^{2}-f$ turbulence model for flow simulation. The Reynolds number based on the bulk mean velocity and the channel height at the diffuser entrance is 18,000. We also perform large eddy simulation to validate the shape design results and investigate the flow characteristics near the zero-skin friction wall. Results from large eddy simulation show that the skin friction is slightly higher than zero but is still very small as compared to that of the flat plate boundary layer flow Although the time-averaged wall shear stress is slightly above zero along the diffuser wall, instantaneous flow reversals occur intermittently. The streamwise mein velocity shows an asymptotic behavior of the half-power-law near the wall where the skin friction is close to zero.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.3
• /
• pp.285-292
• /
• 2015

This paper presents a wireless ground reaction force (GRF) sensing system for ambulatory GRF recording. The system is largely divided into three parts: force sensing modules based on optical sensor, outsole type frame, and embedded system for wireless communication. The force sensing module has advantages of the low height, robustness to the moment interference, and stable response in long term use. In simulation study, the strain and stress properties were examined to satisfy the requirements of the GRF sensing system. Four sensing modules were mounted on the toe, ball, and heel of foot shaped frame, respectively. The GRF signals were extracted using Micrpcontroller unit and transferred to the smart phone via Bluetooth communication. We measured the GRF during the normal walking for the validation of the continuous recording capability. The recorded GRF was comparable to the off the shelf stationary force plate.