• The Korean Journal of Pharmacology
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• v.24 no.2
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• pp.153-164
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• 1988

The potential role of endogenous opioid peptides (EOPS) in cardiovascular regulation has only recently been entertained. EOPS have been localized in brain, spinal cord, autonomic ganglia, particularly the adrenal gland, and many other peripheral tissues. There are at least five major types of opioid receptors; namely ${\mu},\;{\delta},\;k,\;{\sigma},\;and\;{\varepsilon}$ and Experimental evidence indicates that cardiovascular actions of the peptide are mediated primarily by ${\mu},\;{\delta}$ and k receptors, and that these receptor types may be allosterically coupled. In anesthetized rabbits met-enkephalin decreased blood pressure and heart rate, which closely paralleled a reduction in sympathetic discharge. Naloxone, but not naloxone methobromide, antagonized these effects, which suggests a central site of action of met-enkephalin. A number of autonomic agents, particularly adrenergic ${\alpha}$-and, ${\beta}-agonists$ and antagonists modify the cardiovascular actions of met-enkephalin. Experiments in reserpine-treated and adrenalectomized rats provide no evidence of sympathetic nervous system involvement in the pressor responses to intravenous injection of opioid peptides, but rather suggest a direct peripheral action. Finally, activation of a beta-endorphinergic pathway projecting from the arcuate nucleus to the nucleus tractos solitarii in rats can cause naloxone reversible hypotension and bradycardia. There is evidence to implicate this pathway in antihypertensive drug action and in the modulation of baroreflex activity.

• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.75-81
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• 2010

The reaction of N,N-diethyl carbamates of 1H-[1,2,3]triazolo[4,5-b]pyridin-1-ol (4-HOAt) 7, 3H-[1,2,3]triazolo[4,5-b]pyridin-3-ol (7-HOAt) 8, 1H-benzo[d][1,2,3]triazol-1-ol (HOBt) 9, 6-chloro-1H-benzo[d][1,2,3]triazol-1-ol (Cl-HOBt) 10, 6-(trifluoromethyl)-1H-benzo[d][1,2,3]triazol-1-ol ($CF_3$-HOBt) 11, and 6-nitro-1H-benzo[d][1,2,3]triazol-1-ol ($NO_2$-HOBt) 12 with morpholine and piperidine in $CH_3CN$ underwent acyl nucleophilic substitution to give the corresponding carboxamide derivatives. The reactants and products were identified by elemental analysis, IR and NMR. We measured the kinetics of these reactions spectrophotometrically in $CH_3CN$ at a range of temperatures. The rates of morpholinolysis and piperidinolysis were found to fit the Hammett equation and correlated with $\sigma$-Hammett values. The values were 1.44 - 1.21 for morpholinolysis and 1.95 - 1.72 for piperidinolysis depending on the temperature. The $Br{\phi}$nsted-type plot was linear with a $\beta_lg = -0.49 \pm 0.02$ and $-0.67 \pm 0.03$. The kinetic data and structure-reactivity relationships indicate that the reaction of 9-12 with amines proceeds by a concerted mechanism. The deviation from linearity of the correlation ${\Delta}H^#$ vs. ${\Delta}S^#$ and plot of $logk_{pip}$ vs. $logk_{morph}$ and $Br{\phi}$nsted-type correlation indicate that the reactions of amines with carbamates 7 and 8 is attributed to the electronic nature of their leaving groups.

• Journal of the Korean Chemical Society
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• v.36 no.4
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• pp.511-516
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• 1992

The x-values of the nonstoichiometric compound YbO$_x$ have been measured in a temperature range of 600 to 1150$^{\circ}C$ under oxygen partial pressure of 1.00 ${\times}$ 10$^{-2}$ atm∼atmospheric air pressure. The values are varied between 1.55453 and 1.60794 in the conditions. The enthalpy of the formation for x' in YbO$_{1.5＋x'}$(${\Delta}$H$_f$) was 1.55, 1.18, and 1.05 kJ/mol under the above conditions, respectively. The electrical conductivities of the oxides or ${\sigma}$ have been measured in the temperature range from 600 to 1100$^{\circ}C$ under oxygen partial pressure of 1.00 ${\times}$ 10$^{-5}$ ∼ 2.00 ${\times}$ 10$^{-1}$ atm. They varied from 10$^{-9}$ to 10$^{-5}$ ohm$^{-1}$ cm$^{-1}$ within the semiconductor range. The Arrhenius plots of the electrical conductivities show a linearity and the activation energy for the conduction was about 1.7eV. The oxygen partial pressure dependence of the conductivity or 1/n value increases with the pressure. The nonstoichiometric conduction mechanism of the oxide was discussed in terms of the x values, ${\sigma}$ values, and the thermodynamic data.

• Economic and Environmental Geology
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• v.25 no.4
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• pp.417-433
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• 1992

Lead-zinc-copper deposits of the Jeonheung and the Oksan mines around Euiseong area occur as hydrothermal quartz and calcite veins that crosscut Cretaceous sedimentary rocks of the Gyeongsang Basin. The mineralization occurred in three distinct stages (I, II, and III): (I) quartz-sulfides-sulfosalts-hematite mineralization stage; (II) barren quartz-fluorite stage; and (III) barren calcite stage. Stage I ore minerals comprise pyrite, chalcopyrite, sphalerite, galena and Pb-Ag-Bi-Sb sulfosalts. Mineralogies of the two mines are different, and arsenopyrite, pyrrhotite, tetrahedrite and iron-rich (up to 21 mole % FeS) sphalerite are restricted to the Oksan mine. A K-Ar radiometric dating for sericite indicates that the Pb-Zn-Cu deposits of the Euiseong area were formed during late Cretaceous age ($62.3{\pm}2.8Ma$), likely associated with a subvolcanic activity related to the volcanic complex in the nearby Geumseongsan Caldera and the ubiquitous felsite dykes. Stage I mineralization occurred at temperatures between > $380^{\circ}C$ and $240^{\circ}C$ from fluids with salinities between 6.3 and 0.7 equiv. wt. % NaCl. The chalcopyrite deposition occurred mostly at higher temperatures of > $300^{\circ}C$. Fluid inclusion data indicate that the Pb-Zn-Cu ore mineralization resulted from a complex history of boiling, cooling and dilution of ore fluids. The mineralization at Jeonheung resulted mainly from cooling and dilution by an influx of cooler meteoric waters, whereas the mineralization at Oksan was largely due to fluid boiling. Evidence of fluid boiling suggests that pressures decreased from about 210 bars to 80 bars. This corresponds to a depth of about 900 m in a hydrothermal system that changed from lithostatic (closed) toward hydrostatic (open) conditions. Sulfur isotope compositions of sulfide minerals (${\delta}^{34}S=2.9{\sim}9.6$ per mil) indicate that the ${\delta}^{34}S_{{\Sigma}S}$ value of ore fluids was ${\approx}8.6$ per mil. This ${\delta}^{34}S_{{\Sigma}S}$ value is likely consistent with an igneous sulfur mixed with sulfates (?) in surrounding sedimentary rocks. Measured and calculated hydrogen and oxygen isotope values of ore-forming fluids suggest meteoric water dominance, approaching unexchanged meteoric water values. Equilibrium thermodynamic interpretation indicates that the temperature versus $fs_2$ variation of stage I ore fluids differed between the two mines as follows: the $fs_2$ of ore fluids at Jeonheung changed with decreasing temperature constantly near the pyrite-hematite-magnetite sulfidation curve, whereas those at Oksan changed from the pyrite-pyrrhotite sulfidation state towards the pyrite-hematite-magnetite state. The shift in minerals precipitated during stage I also reflects a concomitant $fo_2$ increase, probably due to mixing of ore fluids with cooler, more oxidizing meteoric waters. Thermodynamic consideration of copper solubility suggests that the ore-forming fluids cooled through boiling at Oksan and mixing with less-evolved meteoric waters at Jeonheung, and that this cooling was the main cause of copper deposition through destabilization of copper chloride complexes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.11
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• pp.2444-2450
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• 2011

In this paper, we propose the low fractional spur phase-locked loop(PLL) with multiple phase-frequency detector(PFD). The fractional spurs are suppressed by using a new PFD. The new PFD architecture with two different edge detection methods is used to suppress the fractional spur by limiting a maximum width of the output signals of PFD. The proposed PLL was simulated by HSPICE using a 0.35m CMOS parameters. The simulation results show that the proposed PLL is able to suppress fractional spurs with fast locking.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.165-169
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• 2012

We observed an area of 10 $deg^2$ of the Large Magellanic Cloud using the Infrared Camera (IRC) onboard AKARI. The observations were carried out using five imaging filters (3, 7, 11, 15, and $24{\mu}m$) and the prism disperser ($2-5{\mu}m$, ${\lambda}/{\Delta}{\lambda}{\sim}20$) equipped in the IRC. This paper presents an outline of the survey project and also describes very briefly the newly compiled near- to mid-infrared point source catalog. The $10{\sigma}$ limiting magnitudes are 17.9, 13.8, 12.4, 9.9, and 8.6 mag at 3.2, 7, 11, 15 and $24{\mu}m$, respectively. The photometric accuracy is estimated to be about 0.1 mag at $3.2{\mu}m$ and 0.06 - 0.07 mag in the other bands. The position accuracy is 0.3" at 3.2, 7 and $11{\mu}m$ and 1.0" at 15 and $24{\mu}m$. The sensitivities at 3.2, 7, and $24{\mu}m$ are roughly comparable to those of the Spitzer SAGE LMC point source catalog, while the AKARI catalog provides the data at 11 and $15{\mu}m$, covering the near- to mid-infrared spectral range continuously.

• ETRI Journal
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• v.40 no.2
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• pp.167-179
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• 2018

This paper proposes an IEEE 802.15.4m compliant TV white-space orthogonal frequency-division multiplexing (TVWS)-(OFDM) radio frequency (RF) transceiver that can be adopted in advanced metering infrastructures, universal remote controllers, smart factories, consumer electronics, and other areas. The proposed TVWS-OFDM RF transceiver consists of a receiver, a transmitter, a 25% duty-cycle local oscillator generator, and a delta-sigma fractional-N phase-locked loop. In the TV band from 470 MHz to 698 MHz, the highly linear RF transmitter protects the occupied TV signals, and the high-Q filtering RF receiver is tolerable to in-band interferers as strong as -20 dBm at a 3-MHz offset. The proposed TVWS-OFDM RF transceiver is fabricated using a $0.13-{\mu}m$ CMOS process, and consumes 47 mA in the Tx mode and 35 mA in the Rx mode. The fabricated chip shows a Tx average power of 0 dBm with an error-vector-magnitude of < 3%, and a sensitivity level of -103 dBm with a packet-error-rate of < 3%. Using the implemented TVWS-OFDM modules, a public demonstration of electricity metering was successfully carried out.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.123-124
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• 2008

본 논문에서 설계한 온도센서는 $0.l8{\mu}m$ CMOS 공정으로 $-55^{\circ}C{\sim}125^{\circ}C$의 온도 범위에서 ${\pm}0.1^{\circ}C$의 정확도를 갖는다. 이 센서는 parasitic PNP 트랜지스터로 온도 변화에 따른 전압을 추출하고 시그마-델타 변조기를 이용하여 디지털 온도 값을 얻기 위한 비트스트림을 생성한다. 또한, 이상적이지 않은 요소로 인해 발생할 수 있는 에러를 $0.01^{\circ}C$ 레벨로 감소시키기 위해 DEM(Dynamic Element Matching)과 2차 시그마-델타 변조기를 이용하였고, Bandgap Reference 회로로 온도 변화에 상관없이 일정한 bias 전압을 생성한다. 설계된 온도센서의 면적은 PAD를 포함하여 $0.98mm{\times}0.92mm$이고, 1.8V 단일 전원에서 동작한다.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.388-390
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• 2006

This paper presents a hybrid SoC design for phase detection of single tone signal. The designed hybrid SoC is composed of three functional blocks, i.e., an analog to digital converter module, a phase detection module and a controller module. A design of the controller module is based on a 16-bit RISC architecture. An I/O interface and an LCD control interface for transmission and display of phase measurement values are included in the design of the controller module. A design of the phase detector is based on a recursive sliding-DFT. The recursive architecture effectively reduces the gate numbers required in the implementation of the module. The ADC module includes a single-bit second-order sigma-delta modulator and a digital decimation filter. The decimation filter is designed to give 98dB of SNR for the ADC. The effective resolution of the ADC is enhanced to 98dB of SNR by the incorporation of a pre FIR filter, a 2-stage cascaded integrator- comb(CIC) filter and a 30-tab FIR filter in the decimation. The hybrid SoC is verified in FPGA and implemented in 0.35 CMOS Technology.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.152-153
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• 2004

The growth rate of atmospheric $CO_2$ undergoes significant interannual variability, largely due to temporal variability of partitioning of $CO_2$ between terrestrial biosphere and ocean. In the present paper, as a follow-up to the work by Lee et al. [1], we estimated the year-to-year variability in net global air-sea $CO_2$ fluxes between 1982 and 2003 from observed changes in wind speed and estimated changes in ${\Delta}pCO_2$ Changes in $pCO_{25W}$ were inferred from global records of sea surface temperature (SST) anomalies and seasonally varying SST dependence of $pCO_{25W}$. The modeled interannual variability of $\pm0.2\;Pg\;C\;yr^{-1}\;(1{\sigma})$ from the present work is significantly smaller than the values deduced from atmospheric observations of $^{1.3}CO_2/CO_2$ in conjunction with different atmospheric transport models, but it is closer to the recent estimates inferred from a 3-D ocean biogeochemical model and atmospheric transport models constrained with extensive observations of atmospheric $CO_2$.