• Journal of the Korea Safety Management & Science
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• v.14 no.2
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• pp.83-89
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• 2012

In this study, FDS fire simulation experiments and measured wind speed by applying the exterior installation portion for blocking the spread of the fire was investigated. As a result, aluminum composite panels installed in the lower and the upper part of the panel to remove all the lower side, and then the maximum wind speed 0.24 m/s and the upper side 0.58 m/s were measured. In the FDS, the measured wind speed difference air currents are approximately 3.7 times in 12 seconds, the occurrence of 17 seconds early moment wind 2.2 m/s was measured from. Before and after the fire occurred in early of the air velocity about 39 seconds was 3.5 times difference. Such air currents caused by the temperature of the building but also by the building height was found. Turbulent flame of fire by expanding the vertical extent of damage become greatly important factor. Therefore, through the exterior installation portion of the block that can delay the spread of fire is expected that this should be taken.

• The Korean Journal of Pain
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• v.18 no.1
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• pp.23-28
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• 2005

Background: An epidural steroid injection (ESI) is usually used for the treatment of low back pain with radiculopathy. An ESI can be performed by two procedures: I) a lumbar or caudal epidural steroid injection and II) a transforaminal epidural steroid injection. Methods: Ninety-three patients, who had undergone transforaminal epidural steroid injection (Group II), and either a lumbar or caudal epidural steroid injection (Group I), were retrospectively studied. The authors assessed the pain, walking, standing improvement and side effects after each procedure, which were evaluated as being very good, good, fair or poor. Data were collected from the patients medical records and analyzed using the chi-squared test. P < 0.05 was considered significant. Results: There were no statistically significant differences in the pain, walking, standing improvement and side effects between the two groups. However, there was a statistically significant difference in the pain improvement following transforaminal epidural steroid injection in those not effectively responding to an initial lumbar or caudal epidural block in Group II. Conclusions: A transforaminal epidural steroid injection is a useful alternative to a lumbar or caudal epidural steroid injection for low back pain with radiculopathy.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.562-569
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• 2012

The rubber side could be contaminated using the existing pulse echo method because the ultrasonic wave was incident on the rubber side from the interior of the steel motor case, which could lead to the critical disbond defect. To develop the test method which can be replaced the existing method, the ultrasonic wave was incident on steel face of the steel/rubber adhesive test block. Rubber resonance frequencies measured from the steel/rubber adhesive test block were in good agreement with theoretically predicted rubber resonance frequencies. This paper was described about the ultrasonic resonance method to convert the rubber resonance frequency into the rubber thickness.

• International Journal of Korean Welding Society
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• v.3 no.1
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• pp.34-38
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• 2003

It has been used many kinds of horizontal butt-welding methods at block-to-block erection stage in shipbuilding companies. For examples, some companies use conventional FCAW process with one side or both sides groove joint welding, others use carriage with torch holder type mechanized welding method. Although lots of efforts were done until now, some problems in quality and productivity still remain in ship's hull welding. In this study, we have attempted to raise productivity and quality on horizontal position of welding with following 3 items. 1) Prepare groove condition with no root gap for making easy fit-up work. 2) Develop improved MAG (100% $CO_2$ gas shielding) welding process with solid wire for making sound root bead from one side. 3) Develop and apply quite new automatic welding carriage. The stability of new welding process was confirmed by conducting mechanical tests of weldments to verify the soundness of weldments.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.407-408
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• 2002

This paper presents a split cooling system for a new inline 4-cylinder automotive engine. The split cooling system circulates coolant to the cylinder head and cylinder block separately. The coolant flow in the cylinder block is controlled by a $2^{nd}$ Thermostat installed at the outlet of cylinder block. The $2^{nd}$ thermostat closes when the coolant temperature is low. And this makes the coolant flow in cylinder block nearly stagnant, thereby reducing the coolant-side heat transfer coefficient and raising cylinder bore temperature. The $2^{nd}$ thermostat starts to open when the coolant temperature reaches a specified temperature. The test results on engine dynamometer show improved fuel economy and lower exhaust emission which result from the decrease in friction works and cooling loss. Also, several vehicle tests, with application of the new engine have been performed. Fuel economy improvement of 0.5{\sim}2.0%$ yields from different test modes and details are discussed in this paper.

• The Korean Journal of Pain
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• v.14 no.1
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• pp.41-45
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• 2001

Background: Clonidine, a selective ${\alpha}_2$ adrenergic agonist, increases the duration of anesthesia and analgesia when it is used with local anesthetics. This study was undertaken to evaluate whether clonidine, which was mixed with lidocaine for the brachial plexus block (BPB), has a local (peripheral) or a systemic (central) anesthetic effect. Methods: Seventy patients scheduled for upper extremity surgery were randomly allocated to two groups. In group IV (n = 35) an axillary perivascular BPB was performed with 40 ml of 1% lidocaine and 1：200,000 epinephrine, and just after BPB clonidine $2{\mu}g/kg$ was administered intravenously. In group BPB (n = 35) the same BPB was performed with 40 ml of 1% lidocaine, 1：200,000 epinephrine and clonidine $2{\mu}g/kg$. The following variables were recorded: onset time, duration of anesthesia and analgesia, and adverse effects. Results: Onset time was comparable in both groups. The duration of anesthesia and analgesia significantly increased to 306 min and 354 min in group BPB, when compared to 119 min and 151 min in group IV, respectively. No side effects such as hypotension, bradycardia, and sedation were reported. Conclusions: The duration of anesthesia and analgesia is prolonged by adding clonidine to lidocaine during brachial plexus block, which suggests that its effect is local rather than systemic.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.3
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• pp.215-220
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• 2009

Chlorpheniramine is a potent first-generation histamine $H_1$ receptor antagonist that can increase action potential duration and induce QT prolongation in several animal models. Since block of cardiac human ether-a-go-go-related gene (hERG) channels is one of leading causes of acquired long QT syndrome, we investigated the acute effects of chlorpheniramine on hERG channels to determine the electrophysiological basis for its proarrhythmic potential. We examined the effects of chlorpheniramine on the hERG channels expressed in Xenopus oocytes using two-microelectrode voltage-clamp techniques. Chlorpheniramine induced a concentration-dependent decrease of the current amplitude at the end of the voltage steps and hERG tail currents. The $IC_{50}$ of chlorpheniramine-dependent hERG block in Xenopus oocytes decreased progressively relative to the degree of depolarization. Chlorpheniramine affected the channels in the activated and inactivated states but not in the closed states. The S6 domain mutations Y652A and F656A partially attenuated (Y652A) or abolished (F656A) the hERG current block. These results suggest that the $H_1$ antihistamine, chlorpheniramine is a blocker of the hERG channels, providing a molecular mechanism for the drug-induced arrhythmogenic side effects.

• The Korean Journal of Pain
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• v.8 no.1
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• pp.164-167
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• 1995

Stellate ganglion block(SGB) is a widely used sympathetic block to diagnose or treat various painful conditions. We experienced a rare case who exhihited a contralateral Horner's syndrome following SGB. A 64-year-old female patient suffering from postherpetic neuralgia on mandibular branch of trigeminal nerve visited our pain clinic. She complained of severe burning and shooting pain on right side lower lip, ear and temporal area. We modified her previous medications and performed repeated right SGB daily, in combination with mandibular or mental and auriculotemporal nerve blocks twice a week. Her symptoms were progressively improved. A contralateral Horner's syndrome occured after the thirteenth SGB, which was performed under several attempts in the same manner and the same physician. She had no evidence of subarachnoid or brachial plexus blocks. She did not need any special treatment and returned home 2 hours later. Subsquent blocks were followed on ipsilateral Horner's syndromes.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.137-140
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• 2000

In this paper. we analyzed the performance of a SFH (slow frequency hopping) system under partial-band jamming, multiple access interference and wide-band random noise. For the correction of burst errors due to channel hit, Reed-Solomon coding followed by block interleaving is employed. Errors-and-erasures decoding with side information is exploited to enhance the correctional capability. We derived a closed-form solution for the BER estimation. Errors resulting from random noise and erasures resulting from burst interference are separately analyzed and finally BER is computed due to these composite noise sources. Estimated BER performance is verified by computer simulation.

• Macromolecular Research
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• v.17 no.5
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• pp.313-318
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• 2009

The side chain liquid crystal triblock copolymers (TBCs), which underwent phase transitions below their decomposition temperature, were prepared by copolymerization of poly(n-butyl acrylate) and a comonomer containing the mesogenic azobenzene group. The physical properties of TBCs in the distinctive transition temperature ranges were investigated in terms of the liquid crystal (LC) content in the copolymers. The phase transition temperatures traced optically, thermally and rheologically were well coincided one another and clearly exhibited the phase transition of smectic-nematic-isotropic with increasing temperature. In the smectic phase, increasing temperature made the liquid crystal system more elastic, but viscosity (${\eta}'$) remained almost constant. In the nematic phase, increasing temperature abruptly decreased ${\eta}'$ and G', ultimately leading to isotropic phase. Both smectic and nematic phases exhibited Bingham viscosity behavior but the former gave much greater yield stress at the same LC content.