• The Korean Journal of Pain
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• v.14 no.1
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• pp.123-125
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• 2001

A 50-year-old female patient developed severe right neck and upper extremity pain, hyperesthesia and allodynia during cervical epidural block. Her pain was diagnosed as neuropathic nature. She was treated with repeated stellate ganglion block (SGB) and electrical stimulation (EST). After 3 weeks of treatment, symptomatic relief was achieved, but a mild degree of hyperesthesia and motor weakness was remained. However, she refused all treatment. So treatment was stopped. In a follow-up done, 15 weeks after the nerve injury, she had recovered without complications.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.193-196
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• 2001

In this paper we designed CAMC-SP, the microprocessor embedded 2-axis motor control chip which controls a precise pulse motor by generating the pulse needed to control step motor, DC servo and AC servo motor. This design enables to decrease costs and to minimize a size. First we designed risc type 8-bit microprocessor compatible with PIC16C84, second we designed pulse motor controller. CAMC-SP is integrated of those two block. We designed CAMC-SP by VHDL and we testified to the Performance of it by performing functional simulation.

• Journal of Korea Foundry Society
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• v.25 no.4
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• pp.145-150
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• 2005

• Korea-Australia Rheology Journal
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• v.17 no.1
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• pp.21-25
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• 2005

Rheological properties and crystallization kinetics of the polypropylene (PP) block copolymer and recycled PP block copolymer were studied by advanced rheometric expansion system (ARES), differential scanning calorimetry (DSC), and optical microscopy. In the study of the dynamic rheology, it is observed that the storage modulus and loss modulus for the PP block copolymer and recycled PP block copolymer did not change with frequency. In the study of the effect of the repeated extrusion on the crystallization rate, half crystallization time of the PP samples was increased with the number of repeated extrusion in isothermal crystallization temperature ($T_c$). From the isothermal crystallization kinetics study, the crystallization rate was decreased with the increase of the number of repeated extrusion. Also, from the result of Avrami plot, the overall crystallization rate constant (K) was decreased with the increase of the number of the repeated extrusion. From the study of the optical microscopy, the size of the spherulite of the PP samples did not change significantly with the number of repeated extrusion. However, it was clearly observed that the number of the spherulite growth sites was decreased with the number of repeated extrusion. From the results of the crystallization rate, isothermal crystallization kinetics, Avrami plots, and optical microscopy, it is suggested that the crystallization rate of the PP block copolymer is decreased with the increase of the number of repeated extrusion.

• The Korean Journal of Pain
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• v.22 no.3
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• pp.224-228
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• 2009

Background: Shoulder arthroscopic surgery is frequently associated with severe postoperative pain, which can be difficult to manage without the use of high-dose opioids. Although an interscalene brachial plexus block (ISBPB) can be used to provide anesthesia for shoulder arthroscopic surgery, its effect using low-dose mepivacaine on postoperative pain management has not been reported. We hypothesized that ISBPB using a low-dose mepivacaine can provide effective postoperative analgesia for shoulder arthroscopic surgery without the need for high-dose opioids and act as a significant motor or sensory block. Methods: This study examined a total of 40 patients, who underwent shoulder arthroscopic surgery, and received ISBPB with 10 ml of normal saline (group NS; n = 20) or 10 ml of 1% mepivacaine with epinephrine 1:200,000 (group MC; n = 20). The block was performed preoperatively. The postoperative pain score, opioid consumption, and side effect were recorded. Results: The visual analog scale scores were significantly lower in group MC than in group NS at 120 minutes after shoulder arthroscopic surgery ($1.9{\pm}1.0$ versus $4.0{\pm}1.4$). Group MC showed significantly lower fentanyl consumption after shoulder arthroscoic surgery than group NS ($27{\pm}32.6$ versus $79{\pm}18.9{\mu}g$). The degree of motor and sensory block after surgery was minimal. Conclusions: ISBPB using low-dose mepivacaine reduced the level of postoperative pain and fentanyl consumption without significant side effects. ISBPB using low-dose mepivacaine is a useful analgesic technique for shoulder arthroscopic surgery.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.832-936
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• 1996

In this paper, we study a dynamic characteristics of HDD. HDD is constructed by spindle motor/disk unit, cover, base, E-block arm/suspension unit, and rotary actuator/voice coil motor. First, we make a FE model of spindle motor/disk unit and analyzed natural frequency/mode analytically and experimentally. Especially, the change of natural frequecy of spindle motor unit according to change of B.C is considered. Second, FE model of cover, base is made. Third, we assemble the above three FE mode, we get HEE assembly and dynamic analysis of HDD assembly is accomplished.

• Journal of Power Electronics
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• v.12 no.2
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• pp.305-316
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• 2012

The paper presents an accurate loss model based controller of an induction motor to calculate the optimal air gap flux. The model includes copper losses, iron losses, harmonic losses, friction and windage losses, and stray losses. These losses are represented as a function of the air gap flux. By using the calculated optimal air gap flux compared with rated flux for speed sensorless indirect vector controlled induction motor, an improvement in motor efficiency is achieved. The motor speed performance is improved using a fuzzy logic speed controller instead of a PI controller. The fuzzy logic speed controller was simulated using the fuzzy control interface block of MATLAB/SIMULINK program. The control algorithm is experimentally tested within a PC under RTAI-Linux. The simulation and experimental results show the improvement in motor efficiency and speed performance.

• Journal of the Korean Society for Railway
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• v.9 no.5 s.36
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• pp.612-617
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• 2006

As the on-board electric devices determine the performances of vehicles, production of reliable devices is important. To keep the reliability of devices constant, management of performance evaluation of the on-board devices is crucial. Because temperature has a serious effect on failures of the components of the devices, its measurement is the first step for good management. In this study, we described performance characteristics of domestic auxiliary block developed through G7 project. We measured the performances of auxiliary block during test running by the developed on-line measurement system. After we save the input real-time data from each signal of Korean High Speed Train through the network line, we can acquire necessary information through post-processing program. We verify the motor block characteristics of Korean High Speed Train by this system.

• The Korean Journal of Pain
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• v.1 no.2
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• pp.177-180
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• 1988

Transsacral neurolytic block with 2.5ml of phenol in glycerine or bupivacaine was performed in 6 patients with malignant diseases and a patient with sphincter spasm of bladder due to spinal cord injury. Pain relief was satisfactory in all patints except one patient with very low pain threshold. In one patient, second transsacral neurolytic block alone was not sufficient because of widespread pain along distant metastasis of the malignant disease, although the first block was satisfactory. The complications include transient motor weakness(4), voiding difficulty(1), subarachnoid puncture(1), and epidural venous puncture(1), but they were all spontaneously recovered within a sbort period of time and did not give any limitation to the block.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.168-174
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• 2001

In this paper, a new space vector RPPWM (Random Position PWM) is proposed. In the proposed RPPWM, each of three phase pulses is located randomly in each switching interval. Based on the space vector modulation technique, the duty ratio of the pulses is calculated. Along with the randomization of the PWM pulses, we can obtain the effects of spread spectra of voltage, current as in the case of randomly changed switching frequency. To verify the validity of the proposed RPPWM, simulation study was tried using Matlab/simulink. The main model described in Simulink block diagrams includes the space vector modulation block, pulse position randomization block, inverter block, 3 phase induction motor block, and so on. By the simulation study, the harmonics of the output voltage, and the current of inverter are predicted in different PWM methods- SVPWM, LLPWM, proposed RPPWM.