• The Korean Journal of Pain
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• 제19권1호
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• pp.17-21
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• 2006

Background: Cyclic guanosine monophosphate (cGMP) plays an important role in the modulation of nociception. Although local sildenafil produces antinociception, by increasing cGMP through the inhibition of phosphodiesterase 5, the effect of spinal sildenafil has not been determined. The authors evaluated the effects of intrathecal sildenafil on the nociceptive behavior evoked by formalin injection and thermal stimulation. Methods: Lumbar intrathecal catheters were implanted into rats, with formalin and Hot-Box tests used as nociceptive models. The formalin-induced nociceptive behavior (flinching response) and withdrawal latency to radiant heat were measured, and the general behaviors also observed. Results: The intrathecal administration of sildenafil produced dose-dependent suppression of the flinches in both phases in the formalin test, and increased the withdrawal latency in the Hot-Box test. No abnormal behaviors were noted. Conclusions: Sildenafil, an inhibitor of phosphodiesterase 5, is active against the nociceptive state evoked in the spinal cord by formalin and thermal stimulations. Accordingly, spinal sildenafil may be useful in the management of pain.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.314-314
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• 2012

The dilute magnetic semiconductors (DMS) have been developed to multi-functional electro-magnetic devices. Specially, the Si based DMS formed by ion implantation have strong advantages to improve magnetic properties because of the controllable effects of carrier concentration on ferromagnetism. In this study, we investigated the deep level states of Fe- and Co-ions implanted Si wafer during rapid thermal annealing (RTA) process. The p-type Si (100) wafers with hole concentration of $1{\times}10^{16}cm^{-3}$ were uniformly implanted by Fe and Co ions at a dose of $1{\times}10^{16}cm^{-2}$ with an energy of 60 keV. After RTA process at temperature ranges of $500{\sim}900^{\circ}C$ for 5 min in nitrogen ambient, the Au electrodes with thickness of 100 nm were deposited to fabricate a Schottky contact by thermal evaporator. The surface morphology, the crystal structure, and the defect state for Fe- and Co- ion implanted p-type Si wafers were investigated by an atomic force microscopy, a x-ray diffraction, and a deep level transient spectroscopy, respectively. Finally, we will discuss the physical relationship between the electrical properties and the variation of defect states for Fe- and Co-ions implanted Si wafer after RTA.

• The Korean Journal of Pain
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• 제36권2호
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• pp.163-172
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• 2023

Background: Synaptic plasticity contributes to nociceptive signal transmission and modulation, with calcium/calmodulin-dependent protein kinase II (CaMK II) playing a fundamental role in neural plasticity. This research was conducted to investigate the role of CaMK II in the transmission and regulation of nociceptive information within the nucleus accumbens (NAc) of naïve and morphine-tolerant rats. Methods: Randall Selitto and hot-plate tests were utilized to measure the hindpaw withdrawal latencies (HWLs) in response to noxious mechanical and thermal stimuli. To induce chronic morphine tolerance, rats received intraperitoneal morphine injection twice per day for seven days. CaMK II expression and activity were assessed using western blotting. Results: Intra-NAc microinjection of autocamtide-2-related inhibitory peptide (AIP) induced an increase in HWLs in naïve rats in response to noxious thermal and mechanical stimuli. Moreover, the expression of the phosphorylated CaMK II (p-CaMK II) was significantly decreased as determined by western blotting. Chronic intraperitoneal injection of morphine resulted in significant morphine tolerance in rats on Day 7, and an increase of p-CaMK II expression in NAc in morphine-tolerant rats was observed. Furthermore, intra-NAc administration of AIP elicited significant antinociceptive responses in morphine-tolerant rats. In addition, compared with naïve rats, AIP induced stronger thermal antinociceptive effects of the same dose in rats exhibiting morphine tolerance. Conclusions: This study shows that CaMK II in the NAc is involved in the transmission and regulation of nociception in naïve and morphine-tolerant rats.

• Journal of Magnetics
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• 제11권2호
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• pp.61-65
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• 2006

The physical origin of complex dynamic domain configuration in nonequilibrium magnetic systems with mesoscopic length scales has been studied. An increasing complexity in the spatial feature of the evolution is found to accompany the increasing reversal speed, when a ferromagnetic element is driven by progressively faster switching fields applied antiparallel to the initial magnetization direction. As reversal rates approach the characteristic precession frequencies of spin fluctuations, the thermal energy can boost the magnetization into local configurations which are completely different from those experienced during quasistatic reversal. The sensitive dependence of the spatial pattern on switching speed can be understood in terms of a dynamic exchange interaction of thermally excited spins; the coherent modulation of the spins is strongly dependent on the rise time of switching pulses.

• International Journal of Air-Conditioning and Refrigeration
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• 제10권2호
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• pp.106-115
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• 2002

The performance of an inverter-driven water-to-water heat pump with an electronic expansion valve (EEV) was measured as a function of compressor frequency, load conditions, and EEV opening. Based on the test results, a controller using proportional integral (PI) feedback or PI feedforward algorithm was designed and tested to investigate capacity modulation and transient response control of the system. Although the relation between superheat and EEV opening of the heat pump showed nonlinear characteristics, a control gain obtained at the rated frequency was applicable to various operating conditions without causing large deviations. When the simple PI feedback control algorithm was applied, a large overshoot of superheat and wet compression were observed due to time delay effects of compressor frequency. However, applying PI feedforward control scheme yielded better system performance and higher reliability, compared to the PI feedback algorithm.

• 한국멀티미디어학회논문지
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• 제19권2호
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• pp.352-359
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• 2016

This paper presents high efficiency 5A synchronous DC-DC buck converter. The proposed DC-DC buck converter works from 4.5V to 18V input voltage range, and provides up to 5A of continuous output current and output voltage adjustable down to 0.8V. This chip is packaged MCP(multi-chip package) with control chip, top side P-CH switch, and bottom side N-CH switch. This chip is designed in a 25V high voltage CMOS 0.35um technology. It has a maximum power efficiency of up to 94% and internal 3msec soft start and fixed 500KHz PWM(Pulse Width Modulation) operations. It also includes cycle by cycle current limit function, short and thermal shutdown protection circuit at 150℃. This chip size is 2190um*1130um includes scribe lane 10um.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1727-1731
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• 2004

We propose an ART2 neural network-based fault diagnosis method to diagnose of sensor in the gas monitoring system. In the proposed method, using thermal modulation of operating temperature of sensor, the signal patterns are extracted from the voltage of load resistance. Also, fault classifier by ART2 NN (adaptive resonance theory 2 neural network) with uneven vigilance parameters is used for fault isolation. The performances of the proposed fault diagnosis method are shown by simulation results using real data obtained from the gas monitoring system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.479-482
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• 2003

We propose a real time gas monitoring system for classifying various gases with different concentrations. Using thermal modulation of operating temperature of two sensors, we extract patterns of gases from the voltage across the load resistance. We adopt the relative resistance as a pre-processing method and an ART2 neural network as a pattern recognition method. The proposed method has been implemented in a real time embedded system with tin oxide gas sensors, TGS 2611, 2602 and an MSP430 ultra-low power microcontroller in the test chamber.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.981-982
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• 1998

We fabricated sampled fiber grating by double-exposure method. First, a short-period grating was written into the hydrogen-loaded single mode fiber and then the refractive index was modulated over it by an amplitude mask. It was observed that several transmission dips appear due to the index modulation. The thermal and strain responses were measured over $40-180^{\circ}C$ and $0-1800\mu\varepsilon,$ respectively. The dips have the same and linear sensitivity to both physical quantities over the range of measurement.

• 한국진공학회지
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• 제2권4호
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• pp.468-473
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• 1993

Damages on Si substrate induced by Ar ion implantation and it annealing behavior during rapid thermal annealing were investigated by the cross-sectional TEM (transmissin electron microscopy), RB(Rutherfordbackscattering) spectra an dthermal wave (TW) modulation reflectance methods. Continuous amorphous layer extending to the surface were generated by Ar ion implantation for higher doses than 1 $\times$1015cm-2. The recrystallization of the amorphous layer prodeeded as the annealing temperature increased . However the amorphous /crystal interfacial undulations caused the micro twins and damage clusters. Damage clusters generated by lower doses than 1 $\times$1015 cm-2 disappeared slowly as the annealing temperature increased, but even at 110$0^{\circ}C$ a few damage clusters still remained.