• Proceedings of the KSME Conference
• /
• 2000.04b
• /
• pp.491-496
• /
• 2000

The objective of this study is to increase lift and decrease drag of an airfoil by delaying flow separation with piezo-ceramic actuators. The airfoil used is NACA 0012 and the chord length is 30cm. An experiment is performed at the freestream velocity of 15m/s at which the Reynolds number is $3{\times}10^5$. Seven rectangular actuators are attached to the airfoil surface and move up and down based on the electric signal. At the attack angle of $16^{\circ}$, the separation point is delayed downstream due to momentum addition induced by the movement of the actuators. Drag and lift are measured using an in-house 2-dimensional load cell and the surface pressures are also measured. Lift is increased by 10%, drag is reduced by 50%, and the efficiency is increased to 170%. The flow fields with and without control are visualized using the smoke-wire and tuft techniques.

• Tunnel and Underground Space
• /
• v.4 no.3
• /
• pp.297-304
• /
• 1994

This study aimed at analysis of induced stress and deformation behavior in rock mass around coal seams of Sam Chuck coal mine. For this study Vibrating Wire Stressmeters and Multi-point Borehole Extensometers were installed in the area of coal shale near coal seams. Induced stress and displacement in this area were coutinuously increased for 6 days from the begining of measurement, and then converged. But induced stress and displacement occurred when there were another openings by tunnelling and mining. The value of final induced stress was 21.8kgf/$\textrm{cm}^2$, displacement of rod extensometer was 1.3 mm at arch. Especially, over 1 mm of displacement between E2 and E3 in rod extensometer was measured.

• Proceedings of the KIEE Conference
• /
• 1997.07d
• /
• pp.1339-1341
• /
• 1997

The various type Ag sheathed Bi-2223 tapes have been were fabricated by Powder-in-tube(PIT) process. The critical current density could be improved with the value of $23,000\;A/cm^2$(77 K, zero field) in the single concentric Bi-2223 tape. The bending property dependence of $I_c$ was improved in the double concentric Bi-2223 tape compared with single filamentary and single concentric one.

• Journal of The Korean Radiological Technologist Association
• /
• v.29 no.1
• /
• pp.61-66
• /
• 2003

Purpose : To evaluate was the newly designed gastroduodenal coil catheter: in-vitro test. Material and Method : the coil catheter that we made in our laboratory was 150 cm. The coil that is made of stainless steel wire was composed 1.3m inner diameter and

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.35 no.1
• /
• pp.36-43
• /
• 1986

Superconducting magnet can be employed in many fields, such as, magnet for strong field, superconducting rotating machine and superconducting energy storage system. In this paper, the solenoid magnet design procedure and materials used in construction are described in detail, and those are the fundamentals of superconducting magnet study. The fabrication and test procedure of 3 Tesla superconduting magnet are also described. Nb-Ti is used as a superconducting wire, GFRP and Kapton are used for electrical insulation. Inner diameter of the magnet is 10 cm. According to the test results, the field at the central point of the magnet was 3 Tesla, evaporation rate per hour was 2.7 litter and current at that case was 315 A.

• Journal of the Optical Society of Korea
• /
• v.14 no.3
• /
• pp.282-285
• /
• 2010

We printed a one-dimensional array of metallic wires and a two-dimensional array of metallic split ring resonators on a photo-paper by using a high-dots-per-inch resolution printer and an ink with silver nano-particles. The printed sample sizes are $1.0{\times}1.0cm^2$. The transmission measured by a terahertz time domain spectroscopy system shows that the arrays of wires and split ring resonators could act as polarizers and band-stop filters, respectively, in a terahertz frequency region.

• Journal of information and communication convergence engineering
• /
• v.1 no.1
• /
• pp.27-30
• /
• 2003

Electrophoretic deposition (EPD) of alcohol YBCO suspensions on the Ag wire electrode is studied. Poly(ethylene glycol) was coordinated to a structure formed by the EPD process with YBCO particles. The suspension is characterized in terms of zeta potential and conductivity. The d.c electric fields of 200-300 V/cm are applied for 1-10 min. The optimal condition for the EPD allows modifying the properties and microstructure of the deposited films. Superconducting coatings with nanometer-sized pores and a preferred orientation along the c-axis were prepared from the result with chemically modified precursor solution. In contrast, YBCO coatings of submicrometer-sized pores and randomly orientated grains were prepared from the solution without PEG.

• Transactions on Electrical and Electronic Materials
• /
• v.4 no.5
• /
• pp.6-9
• /
• 2003

Electrophoretic deposition (EPD) of alcohol YBCO suspensions on the Ag wire electrode is studied. Polyethyleneglycol was coordinated to a structure formed by the EPD process with YBCO particles. The d.c electric fields of 200-300 V/cm are applied for 1-10 min. The optimal condition for the EPD allows modifying the properties and microstructure of the deposited films. Superconducting coatings with nanometer-sized pores and a preferred orientation along the caxis were prepared from the result with chemically modified precursor solution. In contrast, YBCO coatings of submicrometer-sized pores and randomly orientated grains were prepared from the solution without PEG.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2004.05a
• /
• pp.117-122
• /
• 2004

Electrophoretic deposition (EPD) of alcohol YBCO suspensions on the Ag wire electrode was studied. Poly(ethylene glycol) was coordinated to a structure formed by the EPD process with YBCO particles. The suspension is characterized in terms of zeta potential and conductivity. The d.c electric fields of 200-300V/cm are applied for 1-10 min. The optimal condition for the EPD allows modifying the properties and microstructure of the deposited films. Superconducting coatings with nanometer-sized pores and a preferred orientation along the c-axis were prepared from the result with chemically modified precursor solution. In contrast, YBCO coatings of sub-micrometer sized pores and randomly orientated grains were prepared from the solution without PEG

• Archives of Plastic Surgery
• /
• v.46 no.3
• /
• pp.267-271
• /
• 2019

A 70-year-old man complained imbalance while walking, inability to perform ankle flexion, and could not stand on tip-toe 3 months after injury. The ankle looked swollen with loss of Achilles contour and obvious gait disturbance. Magnetic resonance imaging shows a 5-cm Achilles tendon gap. Subsequently, surgery was performed to solve the neglected Achilles tendon rupture. Patient was put under general anesthesia with a regional block. Using a nontourniquet technique, a reconstructive procedure was performed using a half-width autologous Achilles tendon graft, which was attached to the calcaneal prominence with wire in a double strand Bunnell fashion. As for the proximal stump, double core Bunnell/modified Kessler suturing was carried out to suture the graft to Achilles stump. To increase the vascularization, an ipsilateral gastrocnemius fascial flap with a distally based-pedicle was harvested to wrap around the tendon graft. At a 6-month follow-up, the patient was able to stand on tip-toe and had also regained a normal gait.