• Transactions of Materials Processing
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• v.24 no.3
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• pp.181-186
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• 2015

Many in the industrial world that consume high amounts of energy are trying to reduce energy when manufacturing their products. Energy saving during manufacturing is a cost reduction. Reduced cost is necessary for profit improvement. The Piston Under Drive Brake used in the current study is an automotive transmission part. The original machining after hot forging was changed to machining after cold forging of a plate in order to save energy and cost. Two extrusion shapes along the outer diameter caused decreased tool life because of the interrupted cut during turning. Therefore, a thickness reduction of two extrusion areas in the outer diameter was needed. The current study suggests an effective way to reduce the thickness of interrupted cut by using progressive blanking.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.27-34
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• 2018

Purpose : To evaluate the effect of carbon couch side rail and vacuum immobilization device in case of lung RPO irradiation. Materials and Methods : The 10, 20, 30 mm thickness of vac-lok's right side were obtained. To measure of doses, glass dosimeters were used and measured reference point is left lung center at the phantom. A, B, C, and D points are left, right, down, and up directions based on the center point. In the state of Side-Rail-Out, place the without vac-lok, with the thickness of 10, 20, and 30 mm vac-lok. After the glass dosimeters was inserted in center, A, B, C, and D points, 100 MU of 6 MV X-ray were irradiated to the referenced center point in the condition of $10{\times}10cm^2$ field size, SAD 100 cm, gantry angle 225, 300 MU/min dose rate. Five measurements were made for each point. In the state of Side-Rail-In, five measurement were made for each point under the same conditions. The average is measured on each of the five Side-Rail-Out and Side-Rail-In measurements. Results : In the presence of side rail, the dose reduction ratio was -11.8 %, -12.3 %, -4.1 %, -12.3 %, -7.3 % for each A, B, C, and D points. In the state of Side-Rail-Out, the dose reduction ratio for the using 10 mm thickness of vac-lok was -0.9 % than without vac-lok. The dose reduction ratio for the using 20 mm thickness of vac-lok was -2.0 %, for the using 30 mm thickness of the vac-lok was -3.0 % than without vac-lok. In the state of Side-Rail-In, the dose reduction ratio for the using 10 mm thickness of vac-lok was -1.0 % than without vac-lok. The dose reduction ratio for the using 20 mm vac-lok was -2.1 %, for the using 30 mm vac-lok was -3.0 % than without vac-lok. Based on the value of no vac-lok dose in the Side-Rail-In state, The dose reduction ratios for the using 10 mm, 20 mm and 30 mm thickness of vac-loks In the Side-Rail-Out that the center point were -12.7 %, -13.7 %, -14.2 % and -12.8 %, -13.8 %, -14.5 % respectively at point A. The dose reduction ratios for the same conditions to the B point were -4.9 %, -6.1 %, -7.1 % and -13.4 %, -14.4 %, -15.5 % respectively at point C. The dose reduction ratios for the same conditions to the D point were -8.4 %, -9.0 %, -10.4 % respectively. Conclusion : The attenuation was caused by presence of side rails and thickness of vac-lok. Pay attention to these attenuation factors, making it a more effective radiation therapy.

• Transactions of Materials Processing
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• v.4 no.2
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• pp.151-158
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• 1995

In this study, the width spreads of spring steel including Mn-Cr steel(SUP 9A), Mn-Cr-V steel(SUP 11A), and Si-Cr steel(SAE 9254) and were investigated under different reduction ratios and thickness-width ratios friction coefficients. The experimental results were compared with the theoretical prediction by the Ekelund equation, Geuze equations, etc. The width spreads of the three spring steels were found to be 10-15% larger than mild steel, and the optimal reduction ratio for the spring steel was found in a range from 20 to30%. Among the spring steels, the width spread of Mn-Cr-V steel was measured to be the largest followed by those of Si-Cr steel and Mn-Cr steel. It was found that the width spread increased with friction coefficient, width-thickness ratio and reduction ratio as predicted. However, the theoretical predictions revealed smaller width spread than the experimental results. This finding indicates that the coefficients of the width spread of the theoretical models need to be modified in order to predict the actual behavior of the width spreading of the spring steels. In this study, the coefficients of width spread of the Geuze equation were determined from the experimental results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.12
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• pp.100-108
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• 2010

A low voltage wire should be used considering that a load used in the end is a low voltage. In regard to these wires, there are needs for research about the wire thickness calculation in accordance with IEC standard because the standardization process for IEC (KS standard) was completed on June 30, 2005, and they stopped producing NEC-standard products by the order from Korean Agency for Technology and Standards under Ministry of Knowledge Economy (former Ministry of Commerce, Industry and Energy) since July 1, 2006. This study compared, in terms of the thickness calculation of low voltage wire, a reduction factor application by IEC standard about allowed current and an application for calculation of voltage drop. It also proposed the formula for IEC standard to decrease errors and resolve the difficulty of standardized calculation by analyzing the difference between simplified formula and standardized formula that are the most frequently used calculation method of voltage drop.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.7
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• pp.253-260
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• 2001

A Study of interior noise reduction in the magelv train is presented. Tarin speed of interest is low such that aero-dynamic noise is negligible and power supply system is a dominant noise source. Based on the measurements of interior noise and acceleration levels during running and zero speed conditions, dominant noise sources are identified. After spectra characteristics of noise sources are investigated several noise reducing methods are studied such as STL increasement of floor panels. sealing. and absorption treatment It is found that the most important noise sources are VVVF inverter and SLM in running condition, whereas air conditioner and DC/DC converter are dominant in zero speed. Sine the major noise sources are under the floor complete sealing and high STL of the floor panel are shown to be the most crucial factors in noise reduction After sound absorbing material, which is polyurethan foam of 50 mm thickness, is thickness, is attached to the downward side of the floor in addition to sealing treatment, the interior noise is reduced by 3~4 dB.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.6
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• pp.117-122
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• 2006

The objective of this study is to analyze the greenroof runoff quantity and delay. The experimental districts, have different soil thickness and vegetation, had installed. A measurement was conducted in Seoul University to investigate the runoff quantity and delay of the greenroof. The measurement point of runoff quality data were 8, located next to each experimental district. Also, the precipitation was measured by rain gauges(# RG2). The experimental investigation lasted from 21th July to 4th December, a total of 137 days. The results showed that the greenroof can contribute runoff retention and delay by soil, but the intensity of actual rain event affected the runoff reduction and delay. Overall, when was the rainy season, percent rainfall retention ranged 17.5% and runoff flow was delayed for 1-3 hours. But on the other hand, when was the typical rain event, percent rainfall retention ranged over 90% and runoff flow was delayed for 1-11 hours. In the result, the greenroof had the greatest runoff retention and delay, while for the typical rain event.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.6
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• pp.1062-1067
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• 2010

The purpose of this study was to estimate skin care effect of Miso Facial Rejuvenation Acupuncture with the facial skin photographing system and ultrasonography. 4 Patients who made first visits to Daegu Oriental Hospital of Daegu Hanny University from August 7, 2009 to August 12, 2009 were each given five-times treatments of Miso Facial Rejuvenation Acupunture. The facial skin photography of each participant was checked two times-pretreatment, posttreatment-using the facial skin photographing system and ultrasonography. The squares and counts of 2parts of facial winkles and thickness of masseter muscle were measured for each one. The squares and counts of facial wrinkles were decreased. The thickness of masseter muscle were decreased. On this study, we could evaluate the wrinkle treatment effects and reduction of masseter muscle of Miso Facial Rejuvenation Acupuncture by an objective method. Miso Facial Rejuvenation Acupuncture has notable effect in wrinkle treatment and reduction of masseter muscle. As though we had not wide experience in this treatment, more research is needed.

• Structural Engineering and Mechanics
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• v.86 no.6
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• pp.779-791
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• 2023

Long-termly used in water supply, an underground concrete pipe is easily subjected to the coupled action of pressure loading and flowing water, which can cause the chemo-mechanical damage of the pipe, resulting in its premature failure and lifetime reduction. Based on the leaching characteristics and damage mechanism of concrete pipe, this paper proposes a coupled chemo-mechanical damage and failure model of underground concrete pipe for water supply, including a calcium leaching model, mechanical damage equation and a failure criterion. By using the model, a numerical simulation is performed to analyze the failure process of underground concrete pipe, such as the time-varying calcium concentration in concrete, the thickness variation of pipe wall, the evolution of chemo-mechanical damage, the distribution of concrete stress on the pipe and the lifetime of the pipe. Results show that, the failure of the pipe is a coupled chemo-mechanical damage process companied with calcium leaching. During its damage and failure, the concentrations of calcium phase in concrete decrease obviously with the time, and it can cause an increase in the chemo-mechanical damage of the pipe, while the leaching and abrasion induced by flowing water can lead to the boundary movement and wall thickness reduction of the pipe, and it results in the stress redistribution on the pipe section, a premature failure and lifetime reduction of the pipe.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1702-1707
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• 2007

The reduction of pipe-thickness induced by flow accelerated corrosion (FAC) is one of the most serious problems on the maintenance of piping system in nuclear power plants (NNP). If the thickness of a pipe component is reduced below the critical level, it cannot sustain pressure and consequently results in leakage or rupture. For this reason, wall thinning by FAC has been inspected in secondary side piping systems in NPPs. In this research Round Robin Test (RRT) was conducted to verify confidence of wall thinning measurement system in NPP. 12 inspectors from 3 companies participated and 23 specimens were used according to standard practice in RRT. The gage R&R analysis was introduced in regard to repeatability and reproducibility that are affected to measurement system errors. Confidence intervals of thickness measurement system were obtained.

• Journal of the Korean Ceramic Society
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• v.21 no.3
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• pp.266-270
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• 1984

The photoelectrochemical properties of the reduced $TiO_2$ceramic electrodes are investigated varying the thickness of the electrodes and the amounts of $Sb_2O_3$ as dopant. As the thickness of the undoped. $TiO_2$ceramic electrode increases the photocurrent tends to decrease. However for the R-F sputtered $TiO_2$ thin film electrodes the photocurrent tends to increase to about 1$\mu\textrm{m}$ thick and then decreases with increasing thickness. For the $TiO_2$ ceramic electrodes doped with $Sb_2O_3$ the photocurrent decreases with inreasing the amounts of dopant and in the case of rapid cooling in air without reduction treatment the photocurrent shows lower value. Also visible light excitation is observed at 500~550(nm) wavelength for the $TiO_2$ ceramic electrodes doped with $Sb_2O_3$comparing wtih the $TiO_2$ ceramic electrodes (~420nm)