• Proceedings of the IEEK Conference
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
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• pp.89-92
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• 2001

In this paper, a simple low-power CMOS current reference circuit is proposed. The reference circuit includes parasitic pnp BJTs and resistors. Temperature compensation is made by adding a current component proportional to a thermal voltage to a current component proportional to a base-to-emitter voltage. The designed circuit has been simulated using a 0.25${\mu}{\textrm}{m}$ n-well CMOS process parameters. The simulation results show that the reference current is 34.96$mutextrm{A}$$\pm$0.04$mutextrm{A}$ in the temperature range of -2$0^{\circ}C$ to 12$0^{\circ}C$ The reference current varies less than 0.6% when the power supply voltage changes from 2.5V to 3.5V For $V_{DD=5V}$ and T=3$0^{\circ}C$ the power consumption is 520㎼ during normal operation but reduces to 0.l㎻ during power-down mode.

• Clinical and Experimental Emergency Medicine
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• 제3권3호
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• pp.148-157
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• 2016

Objective Our aim was to compare the compression quality, exercise intensity, and energy expenditure in 5-minute single-rescuer cardiopulmonary resuscitation (CPR) using 15:1 or 30:2 compression-to-ventilation (C:V) ratios or chest compression only (CCO). Methods This was a randomized, crossover manikin study. Medical students were randomized to perform either type of CPR and do the others with intervals of at least 1 day. We measured compression quality, ratings of perceived exertion (RPE) score, heart rate, maximal oxygen uptake, and energy expenditure during CPR. Results Forty-seven students were recruited. Mean compression rates did not differ between the 3 groups. However, the mean percentage of adequate compressions in the CCO group was significantly lower than that of the 15:1 or 30:2 group ($31.2{\pm}30.3%$ vs. $55.1{\pm}37.5%$ vs. $54.0{\pm}36.9%$, respectively; P<0.001) and the difference occurred within the first minute. The RPE score in each minute and heart rate change in the CCO group was significantly higher than those of the C:V ratio groups. There was no significant difference in maximal oxygen uptake between the 3 groups. Energy expenditure in the CCO group was relatively lower than that of the 2 C:V ratio groups. Conclusion CPR using a 15:1 C:V ratio may provide a compression quality and exercise intensity comparable to those obtained using a 30:2 C:V ratio. An earlier decrease in compression quality and increase in RPE and heart rate could be produced by CCO CPR compared with 15:1 or 30:2 C:V ratios with relatively lower oxygen uptake and energy expenditure.

• Food Engineering Progress
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• 제21권4호
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• pp.403-408
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• 2017

Acetic acid bacteria strains were isolated from a variety of fermented foods and fallen fruits. Among them, the strain MAK88, whose acetic acid fermentation ability, acid-tolerance, and alcohol-tolerance were high, was selected and identified as Acetobacter orientalis. A seed culture of A. orientalis MAK88 was inoculated into onion juice, and the optimum conditions of acetic acid fermentation was investigated. The optimum initial concentration of ethanol in onion juice was 5% (v/v) and in that condition, acidity was 4.31% at 144 h of fermentation. The optimum initial concentration of acetic acid was 1% and the final acidity was 5.32%. The optimum fermentation temperature was determined to be $28^{\circ}C$. The most appropriate preparation method of onion juice was to heat the onion at $121^{\circ}C$ for 15 min and produce juice with pressure followed by filtering, and then sterilization at $121^{\circ}C$ for 15 min. Prepared onion juice was used for fermentation without dilution.

• Korean Journal of Materials Research
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• 제4권6호
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• pp.715-722
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• 1994

Thermochromic $Vo_{2}$ thin films for "smart windows" were prepared by electron beam evaporationmethod on a glass substrate and spectral transmittances were examined by spectrophotometer. Substratetemperature of $300^{\circ}C$ and annealing temperature of $400^{\circ}C$ were found to be effective to give athermochromism on $Vo_{2}$ thin film due to the crystallization of the thin film. Furthermore, annealing of$Vo_{2}$ thin film affected the spectral transmittance and reduced the transmittance significantly at wavelengthbelow 500nm.$V_{0.95}W_{0.05}O_{2}$ thin film doped by 5 atomic percent of W showed semiconductor-metal transition around 0$0^{\circ}V_{0.995}W_{0.005}O_{2}$thin film which contains 0.5 atomic percent Sn showed therrnochrornisrn when it was depositedat substrate temperature of $300^{\circ}C$ and annealed at $450^{\circ}C$ for 5 hours in argon gas. The transitiontemperature of the $V_{0.995}W_{0.005}O_{2}$ thin film was found to be about $25^{\circ}C$ and showed some hysterisis. and showed some hysterisis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집
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• pp.47-52
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• 2004

$HgGa_2S_4$ single crystals were grown by the chemical transport reaction method. The $HgGa_2S_4$ single crystal crystallized into a defect chalcopyrite structure $(I\bar{4})$. The lattice constants of the single crystal were found to be a=5.635 ${\AA}$ and c=10.473 ${\AA}$. The direct and indirect optical energy gaps were found to be 2.84 eV and 2.78 eV, respectively. Photoluminescence peaks of $HgGa_2S_4$ single crystal were observed at 2.37 eV, 2.18 eV, and 1.81 eV. In the single crystal, the donor level of 0.25 eV, the acceptor levels of 0.97 eV and 0.41 eV were obtained by TSC, PICTS, and absorption measurements. The photoluminescence peaks were analyzed to relate to the indirect conduction band, the donor level, and the acceptor levels.

• Journal of IKEEE
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• 제25권1호
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• pp.15-24
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• 2021

In this paper, 1700 V EPDT (Extended P+ shielding floating gate Double Trench) MOSFET structure, which has a smaller switching time and loss than CDT (Conventional Double Trench) MOSFET, is proposed. The proposed EPDT MOSFET structure extended the P+ shielding area of the source trench in the CDT MOSFET structure and divided the gate into N+ and floating P- polysilicon gate. By comparing the two structures through Sentaurus TCAD simulation, the on-resistance was almost unchanged, but Crss (Gate-Drain Capacitance) decreased by 32.54 % and 65.5 %, when 0 V and 7 V was applied to the gate respectively. Therefore, the switching time and loss were reduced by 45 %, 32.6 % respectively, which shows that switching performance was greatly improved.

• Journal of the Korean Magnetics Society
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• 제10권5호
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• pp.246-249
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• 2000

An Fe$_{49}$ Co$_{49}$ V$_2$alloy is annealed in thermal annealing furnace at 50$0^{\circ}C$, 75$0^{\circ}C$, 80$0^{\circ}C$, and 90$0^{\circ}C$. Annealed samples were cooled in air. The magnetostriction is measured by using a Michelson laser interferometer. Receiving the feedback signal of interference, a mirror attached to piezoelectric transducer (PZT) maintains the optical path length (OPL) between two arms of laser interferometer relatively constant. The feedback voltage is calibrated to the OPL variation. A magnetostriction of 2$\times$10$^{-6}$ at H = 60 Oe increases up to 33.68$\times$10$^{-6}$ at an annealing temperature of 90$0^{\circ}C$, suggesting that the magnetostrictive characteristics are improved by the microstructural modification.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제27권3호
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• pp.292-298
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• 1994

An environmental study was done to examine the distribution of Vibrio mimicus in aquatic environments of Kwangan and Minrak beach, Pusan, Korea. Moreover, both bacteriological characteristics and lethal effects of isolated V. mimicus were observed. Sea water samples were collected monthly from January to September, 1993, and quantitatively analyzed for V. mimicus. This organism was isolated from April(water temperature was $16.3^{\circ}C$), whereas it was not isolated when the water temperature fell below $15^{\circ}C$. V. mimicus counts were not remarkably high, however this study at least describes the distribution and occurrence of the possible highest density in aquatic environments of this region. Among the confirmed V. mimicus strains, the author chose the strongest antibiotic resistant bacterium and named it V. mimicus K-1. This strain has antibiotic resistance to colistin, erythromycin, tetracycline, and penicillin, and most isolates had a higher level of antibiotic resistance than V. mimicus ATCC 33653. The optimum growth for V. mimicus K-1 was observed at $37^{\circ}C$, pH 7.5, and $1\%$ NaCl, respectively. This organism was mostly inactivated by Ultra Violet irradiation (30W, $50^{\circ}C$) for 70 seconds and death lethality increased in proportion to treatment temperature ($D_{50}=5.7min,\;D_{60}=\;2.1min,\;and\;D_{70}=0.7min$).

• Communications of the Korean Mathematical Society
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• 제27권3호
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• pp.557-564
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• 2012

This study concerns the existence of positive solution for the following nonlinear system $$\{-div(|x|^{-ap}|{\nabla}u|^{p-2}{\nabla}u)=|x|^{-(a+1)p+c_1}({\alpha}_1f(v)+{\beta}_1h(u)),x{\in}{\Omega},\\-div(|x|^{-bq}|{\nabla}v|q^{-2}{\nabla}v)=|x|^{-(b+1)q+c_2}({\alpha}_2g(u)+{\beta}_2k(v)),x{\in}{\Omega},\\u=v=0,x{\in}{\partial}{\Omega}$$, where ${\Omega}$ is a bounded smooth domain of $\mathbb{R}^N$ with $0{\in}{\Omega}$, 1 < $p,q$ < N, $0{{\leq}}a<\frac{N-p}{p}$, $0{{\leq}}b<\frac{N-q}{q}$ and $c_1$, $c_2$, ${\alpha}_1$, ${\alpha}_2$, ${\beta}_1$, ${\beta}_2$ are positive parameters. Here $f,g,h,k$ : $[0,{\infty}){\rightarrow}[0,{\infty})$ are nondecresing continuous functions and $$\lim_{s{\rightarrow}{\infty}}\frac{f(Ag(s)^{\frac{1}{q-1}})}{s^{p-1}}=0$$ for every A > 0. We discuss the existence of positive solution when $f,g,h$ and $k$ satisfy certain additional conditions. We use the method of sub-super solutions to establish our results.

• Journal of the Korean Institute of Telematics and Electronics C
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• 제35C권11호
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• pp.57-62
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• 1998

In this paper, tunable transconductor shows good linearity over a wide input voltage range are proposed. The proposed transconductor employ operating in the nonsaturation(ie., linear) region to improve circuit simplicity and tunability and 6.8V$\_$p-p/ wide input range. Also the circuit employ source-coupled differential pair to provide true differential input and can achieve both positive and negative transconductance values. The proposed circuits are implemented using a 1.2 $\mu\textrm{m}$ single poly double metal n-well CMOS technology. The THD characteristic of proposed circuit is less than 1% for a differential input voltage of up to 6V$\^$p-p/ when supply bias condition is V$\_$DD/=-V$\_$ss/=5V, I$\_$B/=20, 40${\mu}$A, and frequency of input signal is 1KHz.