• Archives of Plastic Surgery
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• v.39 no.3
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• pp.227-231
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• 2012

Background : The ankle brachial pressure index (ABI) is a simple, useful method for diagnosing peripheral artery disease (PAD). Although the ABI is an objective diagnostic method, it has limited reliability in certain scenarios. The aim of the present study was to determine the accuracy and reliability of the toe brachial index (TBI) as a diagnostic tool for detecting stenosis in PAD, associated with normal or low ABI values. Methods : ABI and TBI values were measured in 15 patients with diabetic gangrene who were suspected of having lower extremity arterial insufficiency. The ABI and TBI values were measured using a device that allowed the simultaneous measurement of systolic blood pressure in the upper and lower extremities. In addition, the ABI and TBI values were compared pre- and post-angiography. Results : Patients with an ABI of 0.9-1.3 showed almost no difference between the 2 measurements. The patients with TBI >0.6 had no arterial insufficiency. The patients with TBI <0.6 required vascular intervention with ballooning. After the angiography, the gangrenous wounds decreased in size more rapidly than they did prior to the intervention. Conclusions : Our findings suggest that TBI is the method of choice for evaluating lower limb perfusion disorders. This result requires further studies of TBI in a larger number of patients. Future long-term studies should therefore evaluate the utility of TBI as a means of screening for PAD and the present findings should be regarded as preliminary outcomes.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.149-156
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• 2007

Non-contact transportation of the large-sized glass plate using air-cushion is considered for sputtering system of LCD panel. The Argon gas from second gas injection holes is injected to levitate and transport the glass plate. Low maximum pressure and uniform pressure distribution on the bottom surface of the glass plate must be maintained for stable levitation and transportation of the glass plate. Therefore, the analysis of fluid flow between the glass plate and the air-pad is numerically performed for varying space between the injection holes in this study. The pressure uniformity on the bottom surface of the glass plate is evaluated for overall glass plate. The distance between the injection holes must be designed below 90 mm for obtaining the low maximum pressure and uniform pressure distribution.

• Transactions of Materials Processing
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• v.26 no.2
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• pp.87-94
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• 2017

Center pillar, which is installed in the center of flank of car body, supports roof and door and ensures the safety of driver by reducing the damage of car body caused by impact. Recently, high-strength steel is widely used to manufacture the center pillar due to high stiffness and fuel efficiency. In this study, material properties of the high-strength steel, whose tensile strength is more than 780MPa, were obtained to produce the center pillar. Stamping was performed by considering the design parameters (blank holder force, press stroke, blank size and pad pressure) used in the actual filed. The drawbeads were included in the stamping process to reduce the amounts of wrinkling and spring back. Using the commercial software, Autoform R5.2 and Minitab, effects of design parameters of the stamping process upon spring back were analyzed and applied to the design process. The restriking process meets the target of under 0.5mm in the amount of spring back.

• Tribology and Lubricants
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• v.25 no.6
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• pp.421-426
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• 2009

The brake system is important part of automobile safety system. The disc brake system is divided two parts: the rotating axisymmetrical disc and the stationary pads. During braking, the kinetic energy and potential energy of moving vehicle were converted into the thermal energy through frictional heat between the brake disc and the pads. The frictional heat, which is generated on the interface of the disc and pads, can cause high temperature during the braking process. The object of present work is to determine temperature and thermal stress, to compare to simulation results and experimental results in the disc by partial 3D model of ventilated disc brake with appropriate boundary conditions. In the simulation process, the mechanical loads were applied to the thermo-mechanical coupling analysis in order to simulate the process of heat produced by friction.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.3
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• pp.95-103
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• 2010

Roll to Roll (R2R) is one of the most promising production technologies in the printed electronics such as OLEDs, e-paper, backplanes, RFID because this technology can save production cost and increase production speed. Printed electronics includes various processes such as printing, drying, winding, unwinding, and so on. In printed electronics R2R system, air-flotation oven is employed for drying process. Therefore, it is essential to introduce efficient and fast drying process when printing is finished. This paper considers the analysis of drying process in R2R that involves hot air flow. Air-flotation oven consists of non-contact supports and drying of coated web materials such as plastic films and paper. In this paper, experimental results and numerical analysis of pressure-pad air bar are investigated. The aerodynamic characteristics of pressure-pad air bar are numerically calculated using computational fluid dynamics (CFD) approach. Then the measured values of the aerodynamic forces for air bars are compared with those of CFD analysis.

• Transactions of Materials Processing
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• v.24 no.2
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• pp.77-82
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• 2015

By investigating the practical use of trim punch configurations for shearing of vehicle panels, the current study first reviews the shearing angle as part of the shearing die design. Based on this review, four different types of trim punch shapes (i.e., horizontal, slope, convex, and concave type) and shearing angles(i.e., 0.76°, 1.53°, 2.29°, 3.05°, 3.81°) were investigated. In order to conduct shearing experiments, four types of trim punch dies were made. The four trim punch dies were tested under various conditions. The experiments used the four trim punch shapes and the five shearing angles. The shearing force varied by shape and decreased from horizontal, slope, convex, to concave for the same shearing angle. The magnitude of shearing force showed differences between the convex and the concave shapes due to the influence of constrained shearing versus free shearing. The test results showed that compared to the horizontal trim punch shearing force, the decrease of the slope, convex, and concave shearing forces were 22.6% to 60.4%. Based on the results, a pad pressure of over 30% is suggested when designing a shearing die.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.6
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• pp.951-960
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• 1997

Package crack caused by the soldering process in the surface mounting plastic package is evaluated by applying the maximum energy release rate criterion. It could be shown that the crack propagation from the lower edge of the ie pad is easily occurred at the maximum temperature during the soldering process, where the pressure acting on the crack surface is assumed by the saturated vapor pressure at maximum temperature. The package crack formation depends on various parameters such as chip size, relative thickness, material properties, the moisture content and soldering temperature etc. The quantitative measure of the effects of the parameters could be easily obtained by using the taguchi's method which requires only a few kinds of combinations with such parameters. From the results, it could be obtained that the more significant parameters to effect the package reliability are the orders of Young's modulus, die pad size, down set, chip thickness and maximum soldering temperature.

• International Journal of Precision Engineering and Manufacturing
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• v.3 no.2
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• pp.87-94
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• 2002

This paper presents the synchronous vibration control of a rotor system using an Active Air Bearing(AAB). In order to suppress the synchronous vibration, it is necessary to actively control the air film pressure or the air film thickness. In this study, active pads are used to control the air film thickness. Active pads are supported by the pivots containing piezoelectric actuators and their radial positions can be actively controlled by applying voltage to the actuators. Disturbances and various kinds of external forces can cause the shaft vibration as well as the change of the air film thickness. The dynamic behaviors of a rotary system supported by two tilting-pad gas bearings and its active stabilization using the tilting-pads as actuators are investigated numerically. The PID controller is applied to the tilting-pad gas bearing system with three pads, two of which contain piezoelectric actuators. To test the validity of the theoretical method, the performance of this control method is evaluated through experiments. The experimental results show the effectiveness of the control system for suppressing the unbalanced response of the rigid modes.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.3
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• pp.783-788
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• 2004

Cheonmabanhwa- Tang (CBT) has been used in the Oriental Medicine for many centuries as a therapeutic agent for dizziness due to Poong-Dam, We reported that CBT had effects on the cerebral hemodynamics [regional cerebral blood flow (rCBF), pial arterial diameter (PAD), and mean arterial blood pressure (MABP)] in normal and cerebral ischemic rats. Therefor we designed to determine the mechanism of action of CBT. The changes of rCBF and MABP were determinated by laser-Doppler flowmetry(LDF), and the change of PAD was determinated by video-microscopy. The results were as follows: The CBT-induced increase in rCBF was significnatly inhibited by pretreatment with indomethacin (IDN, 1 ㎎/㎏, i.p.), an inhibitor of cyclooxygenase, or methylene blue (MTB, 10 ㎍/㎏, i.p.), an inhibitor of guanylate cyclase. The CBT-induced increase in PAD was also significantly inhibited by pretreatment with IDN or MTB. The CBT-induced increase in MABP was also significantly inhibited by pretreatment with IDN or MTB. In conclusion, it is suggested that CBT causes a diverse effect on cerebral hemodynamics via mediation of cyclooxygenase and guanylate cyclase.

• Fashion & Textile Research Journal
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• v.22 no.3
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• pp.271-286
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• 2020

This study evaluated designs via the consumers' function and design preferences survey for using product design images, virtual avatar wearing images and product explanations that identified consumers' function and design preferences for knee protection pads as well as to develop movement assistive knee pad designs. We developed Design A for men and Design B for women. For Design A, the front of the knee supports muscles and alleviates pain with a hole. Mesh material with good ventilation was applied to enhance wearing comfort. The color was achromatic for a modern style, and the hook fastener and loops enabled easy wear and removal of the pad while controlling size and pressure strength. For Design B, taping details seamlessly support muscles in the knee area with fabrics less than 0.1 cm thick and with long sleeves in the diverse sizes. The design's satisfaction assessment showed that potential consumers were satisfied with Design A and Design B for overall design and functional features. Over 77% wanted to use/wear and purchase designs; in addition, over 78% expected it would help with walking and relieve knee pain. The results can be helpful for designers when deciding designs for manufacturing and commercializing kneepad products.