• Korean Journal of Crystallography
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• v.6 no.2
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• pp.141-157
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• 1995

Single crystals of TeO2 with large diameter were grown by Czochralski technique with auto-diameter control system. The ratio of crystal to crucible was 60-70%. The effect of critical pulling and rotation rate on the crystal quality was studied. Optimum growth parameters for high quality crystal pulling rate was less than 1.2 mm/hr. The solid-liquid interface was convex at the rotation rate of 10-23 rpm and concave at the rotation rate of more than 25 rpm, depending on the size of crystal and crucible. The platinum concentration in the melts is one of the main factors of the constitutional supercooling and thus the bubble entrapment in the growing crystal. Growth axis was confirmed to {110} direction during the whole growth procedure. Infrared spectrometric study and dislocation density measurment by chemical etching method on the grown crystal were performed. Finally, the reasons of cooperation of striations, inclusions, and optical inhomogeneities were discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.5
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• pp.676-682
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• 2014

In this paper, precipitation echo(PRE) and non-precipitaion echo(N-PRE)(including ground echo and clear echo) through weather radar data are identified with the aid of neuro-fuzzy algorithm. The accuracy of the radar information is lowered because meteorological radar data is mixed with the PRE and N-PRE. So this problem is resolved by using RBFNN and judgement module. Structure expression of weather radar data are analyzed in order to classify PRE and N-PRE. Input variables such as Standard deviation of reflectivity(SDZ), Vertical gradient of reflectivity(VGZ), Spin change(SPN), Frequency(FR), cumulation reflectivity during 1 hour(1hDZ), and cumulation reflectivity during 2 hour(2hDZ) are made by using weather radar data and then each characteristic of input variable is analyzed. Input data is built up from the selected input variables among these input variables, which have a critical effect on the classification between PRE and N-PRE. Echo judgment module is developed to do echo classification between PRE and N-PRE by using testing dataset. Polynomial-based radial basis function neural networks(RBFNNs) are used as neuro-fuzzy algorithm, and the proposed neuro-fuzzy echo pattern classifier is designed by combining RBFNN with echo judgement module. Finally, the results of the proposed classifier are compared with both CZ and DZ, as well as QC data, and analyzed from the view point of output performance.

• Journal of Veterinary Clinics
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• v.27 no.2
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• pp.136-141
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• 2010

The aim of this study is to investigate whether medetomidine (MED) and tiletamine/zolazepam (ZT) combination in dogs provide the sufficient analgesia during the period of the stage of surgical anesthesia determined by the response to the noxious stimuli, which were evaluated by the change of electroencephalogram (EEG) and hemodynamic values. Seven clinically healthy, adult beagle dogs were used. They were used repeatedly at interval of a week, according to a randomized design. This study had 2 experimental groups. In Group 1, dogs received $30\;{\mu}g/kg$ of medetomidine and 10 mg/kg of tiletamine/zolazepam. Both drugs were administered intramuscularly. In Group 2, dogs were medicated with the same method as in Group 1, except the pedal withdrawal reflex test was done. In Group 2, interdigital regions were grasped with a mosquito forceps for 30 seconds, every 5 min from 10 min to 45 min after ZT injection. During all recording stages, the power for each band, mean arterial pressure and heart rates were calculated. On EEG, no significant changes were observed between groups. Although mean arterial pressure and heart rate were increased 10 min after ZT injection, no significant differences were observed between groups. In conclusion, the MED and ZT anesthesia in dogs are seemed to provide a satisfactory analgesic effect during the period of surgical anesthesia based on EEG with pedal withdrawal reflex test.

• Korean Journal of Materials Research
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• v.20 no.11
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• pp.617-622
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• 2010

We have studied methods to save Si source during the fabrication process of crystalline Si solar cells. One way is to use a thin silicon wafer substrate. As the thickness of the wafers is reduced, mechanical fractures of the substrate increase with the mechanical handling of the thin wafers. It is expected that the mechanical fractures lead to a dropping of yield in the solar cell process. In this study, the mechanical properties of 220-micrometer-solar grade Cz p-type monocrystalline Si wafers were investigated by varying saw-damage etching conditions in order to improve the flexural strength of ultra-thin monocrystalline Si solar cells. Potassium hydroxide (KOH) solution and tetramethyl ammonium hydroxide (TMAH) solution were used as etching solutions. Etching processes were operated with a varying of the ratio of KOH and TMAH solutions in different temperature conditions. After saw-damage etching, wafers were cleaned with a modified RCA cleaning method for ten minutes. Each sample was divided into 42 pieces using an automatic dicing saw machine. The surface morphologies were investigated by scanning electron microscopy and 3D optical microscopy. The thickness distribution was measured by micrometer. The strength distribution was measured with a 4-point-bending tester. As a result, TMAH solution at $90^{\circ}C$ showed the best performance for flexural strength.

• Journal of Yeungnam Medical Science
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• v.18 no.1
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• pp.67-74
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• 2001

Background: Meralgia paresthetica(MP) which is characterized by paresthesias and sensory impairment without motor weakness in the anterolateral aspects of the thigh is produced by compression of the lateral femoral cutaneous nerve(LFCN). Even though the diagnosis of MP is mostly based on the clinical symptoms, electrophysiologic study is mandatory to confirm the disease objectively. It has been known that Somatosensory evoked potential(SSEP) study of LFCN is a simple and very useful method to evaluate MP, so we studied SSEP of LFCN in normal adults and offer normal values. Materials and Methods: Thirty six normal adults(23 males and 13 females) ages from 21 to 73 years old($mean{\pm}SD$:$42.06{\pm}15.74$) were studied SSEP of LFCN bilaterally. The stimulation site was anterolateral aspect of thighs and the recording site was Cz'. Results: The mean values($mean{\pm}SD$) of $LP_0$, $SP_0$, $LN_1$ and $SN_1$ of all subjects were 35.10(${\pm}2.42$), 33.80(${\pm}2.4$), 43.68(${\pm}1.88$) and 42.16(${\pm}2.12$) and the mean values($mean{\pm}SD$ of $DP_0$, $DN_1$ and DA(${\mu}V{\pm}SD$ were 1.30(${\pm}1.14$), 1.52(${\pm}1.38$) and 0.32(${\pm}0.33$). Conclusion: For the diagnosis of MP. comparison of latency difference between both sides is more reliable than simple value of latency itself because of individual differences of body types. According to our results. the latency difference should be less than 2 msec and the amplitude difference was less than 1.6 times in normal adults.