• Textile Coloration and Finishing
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• v.6 no.1
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• pp.19-27
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• 1994

Mimosa and Quebracho are, in general, tanned with leather skin, finished silk fabrics according to temperature, treatment time, tannin concetration, pH, and studies that relation between tannin weighting and various factors. This makes fundamental study on characteristic of tannin treated fabrics. and the results are as fallows : 1. λ$_{max}$ was found at 278.5nm for Mimosa. 279.5nm for Quebracho. Also a stability was good in standing time and heating. 2. The higher tannin treatment temprature was, the better tannin weighting effect was. But they were slightly decreased at over 8$0^{\circ}C$, and K/S was slowly increased. 3. As tannin treatment time increased, tannin weighting effect increased but they were decreased at over 8$0^{\circ}C$, 90min. 4. As tannin concentration increased, tannin weighting was increased. 5. In tannin weighting effect according to various pH conditions, the it's best range of pH were 3.5~5.5 of Mimosa, 2.5~3.5 of Quebracho.o.

• Analytical Science and Technology
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• v.8 no.3
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• pp.249-258
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• 1995

The polymers, polyazine, polyazomethine ( I ) and polyazomethine ( II ) were prepared by the condensation of p-benzoquinone with hydrazine hydrate, p-phenylenediamine and diaminomaleonitrile in DMSO, respectively. The IR spectra of these polymers showed a characteristic peak of schiff base (-C=N-) at about $1600cm^{-1}$. These polymers dissolved in concentrated sulfuric acid showed UV/VIS absorption near 300nm indicatiog the presence of iminium ion(>$C\limits^{\small\oplus}=NH-$). Another UV/VIS absorption band in the region of 350~415nm was shown presumably due to the charge transfer transition in the molecule. The electrical conductivities of polyazine, polyazomethine ( I ) and ( II ) were measured. The self-electrical conductivity of these was found to be about $10^{-14}{\sim}10^{-11}{\Omega}^{-1}cm^{-1}$ and these polymers doped with $I_2$ showed the maximum conductivity of about $10^{-2}{\Omega}^{-1}cm^{-1}$.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1495-1498
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• 2008

We proposed driving method with variable integration time for ambient light sensing. One operation period of the proposed driving method consists of several sub-integration periods with variable integration time which can enlarge dynamic range of ambient light sensing circuit. Temperature dependent characteristic of p-intrinsic-metal (p-i-m) diode can be compensated using the proposed driving method.

• IEIE Transactions on Smart Processing and Computing
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• v.5 no.1
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• pp.10-16
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• 2016

In this paper, a design for a fully digital voltage sensor using a 32-nm fin-type field-effect transistor (FinFET) is presented. A new characteristic of the double gate p-type FinFET (p-FinFET) is examined and proven appropriate for sensing voltage variations. On the basis of this characteristic, a novel technique for designing low-power voltage-to-time converters is presented. Then, we develop a digital voltage sensor with a voltage range of 0.7 to 1.1V at a 50-mV resolution. The performance of the proposed sensor is evaluated under a range of voltages and process variations using Simulation Program with Integrated Circuit Emphasis (SPICE) simulations, and the sensor is proven capable of operating under ultra-low power consumption, high linearity, and fairly high-frequency conditions (i.e., 100 MHz).

• Korean Journal of Materials Research
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• v.29 no.12
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• pp.764-773
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• 2019

The gas response characteristic toward C₂H₅OH has been demonstrated in terms of copper-vacancy concentration, hole density, and microstructural factors for undoped/Li(I)-doped CuO thin films prepared by sol-gel method. For the films, both concentrations of intrinsic copper vacancies and electronic holes decrease with increasing calcination temperature from 400 to 500 to 600 ℃. Li(I) doping into CuO leads to the reduction of copper-vacancy concentration and the enhancement of hole density. The increase of calcination temperature or Li(I) doping concentration in the film increases both optical band gap energy and Cu2p binding energy, which are characterized by UV-vis-NIR and X-ray photoelectron spectroscopy, respectively. The overall hole density of the film is determined by the offset effect of intrinsic and extrinsic hole densities, which depend on the calcination temperature and the Li(I) doping amount, respectively. The apparent resistance of the film is determined by the concentration of the structural defects such as copper vacancies, Li(I) dopants, and grain boundaries, as well as by the hole density. As a result, it is found that the gas response value of the film sensor is directly proportional to the apparent sensor resistance.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.11
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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.

• The Korean Journal of Nuclear Medicine
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• v.9 no.1
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• pp.59-71
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• 1975

53 patients with hyperthyroidism have been analyzed with special reference to therapeutic response to radioactive iodine ($^{131}I$) treatment. Mean effective half-life, 24 hour uptake rate and radiation dose of $^{131}I$ in hyperthyroid patients included in this study were respectively. 1. Mean effective half-life of $^{131}I\;was\;4.7{\pm}1.5$ days in the tracer dose and $5.0{\pm}1.5$ days in the therapeutic dose. 2. Mean 24 hour uptake rate of $^{131}I\;was\;72.7{\pm}11.1%$ in the tracer dose and $73.4{\pm}12.3%$ in the theapeutic dose. 3. Mean radiation dose of $^{131}I\;was\;5,319{\pm}2,648$ RAD as predicted and $5,692{\pm}2,843$ RAD as actual. A single dose of radioactive iodine treatment was satisfactory in 34 patients (radioiodine sensitive) and multiple doses of radioactive iodine treatments were required in 19 patients (radioiodine resistant). A radioiodine resistant group of patients with hyperthyroidism was distinctively characteristic in the following aspects. 1. Mean thyroid weight calculated in the resistant group ($63.9{\pm}14.0gm$) was significantly (p<0.01) greater than that of the sensitive group ($46.6{\pm}13.3gm$). 2. Mean 24 hour uptake rate of the tracer dose in the resistant group ($67.3{\pm}10.7%$) was significantly (p<0.01) lower than that of the sensitive group ($75.7{\pm}10.5%$). 3. Mean 24 hour uptake rate of the therapeutic dose in the resistant group ($68.5{\pm}13.7%$) was significantly (p<0.05) lower than that of the sensitive group ($76.1{\pm}10.9%$). 4. Mean predicted radiation dose, of $^{131}I$ in the resistant group ($3,684{\pm}1,745$ RAD) was significantly (p<0.01) lower than that of the sensitive group ($6,232{\pm}2,683$ RAD). 5. Mean actual radiation dose of $^{131}I$ in the resistant group ($4,100{\pm}1,691$ RAD) was significantly (p<0.01) lower than that of the sensitive group ($6,582{\pm}3,024$ RAD). 6. No significant difference was detected in terms of effective half-life of $^{131}I$ among the groups (p>0.05). 7. The average mean % difference of effective half-life, uptake rate and radiation dose measured following the tracer and therapeutic dose of $^{131}I$ were not statistically significant (p>0.05). Therefore effective half-life, uptake rate and radiation dose of the therapeutic dose of $^{131}I$ were readily predictable following the tracer dose of $^{131}I$. 8. It is concluded that the possibility of resistance to radioactive iodine treatment may be anticipated in patients with thyroid gland large in size and compromised $^{131}I$ uptake rate.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.4
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• pp.249-256
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• 1997

To identify the long-term influence of acid rain treatment on tree growth, acid rain of various composition (pH 2.0, pH 4.0 and pH 5.6 as control) was applied to several landscape trees for five months (April through August, 1991). Tree height, pH values and $Al^{3+}$ concentration in soil were investigated. Acid rain treatments seemed to promote height growth in the first year (1991), but have become an inhibiting factor over five years. All of coniferous species and most broad-leaved species, except Acer ginnala, showed opposite trends in height responses to acid rain treatments between the first (1991) and last (1996) year. In contrast, Acer ginnala showed similar trends to acid rain treatments in the height growth between 1991 and 1996. This result suggested that Acer ginnala has a characteristic adapability to acid rain stress. pH values of surface soil were lower than those of 30 cm soil depth. This fact suggested that acid rain treatments made surface soil acidic condition. In addition, physiological characteristics (photosynthesis, stomatal condition and biomass) have to be investigated to identify the relationship between long-term effects of $AL^{3+}$ concentration and growth.

• Journal of Power System Engineering
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• v.9 no.2
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• pp.93-98
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• 2005

The performance of cooling tower is dependent on the thermal performance of the packings. It's assessed by heat transfer rate and fan power. In this study, new packing was developed for application in compact type cross-flow cooling tower. The packing characteristic curve and the pressure drop curve were obtained by measuring packing characteristic values and pressure drops of small sized filler in comparison to existing mid-large sized filler. The heat transfer characteristics on small sized filler are about 66% higher than existing mid-large sized filler. The pressure drop characteristics on small sized filler are about two times of the pressure drop characteristics on existing mid-large sized filler.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.569-575
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• 2020

Recently, research on renewable energy technologies has come into the spotlight due to rising concerns over the depletion of fossil fuels and greenhouse gas emissions. Demand for portable electronic and wearable devices is increasing, and electronic devices are becoming smaller. Energy harvesting is a technology for overcoming limitations such as battery size and usage time. In this paper, the V-I characteristic curve and internal resistance of thermal electric devices were analyzed, and MPPT control methods were compared. The Perturbation and Observation (P&O) control method is economically inefficient because two sensors are required to measure the voltage and current of a Thermoelectric Generator(TEG). Therefore, this paper proposes a new MPPT control method that tracks MPP using only one sensor for the regulation of the output voltage. The proposed MPPT control method uses the relationship between the output voltage of the load and the duty ratio. Control is done by periodically sampling the output voltage of the DC-DC converter to increase or decrease the duty ratio to find the optimal duty ratio and maintain the MPP. A DC-DC converter was designed using a cascaded boost-buck converter, which has a two-switch topology. The proposed MPPT control method was verified by simulations using PSIM, and the results show that a voltage, current, and power of V=4.2 V, I=2.5 A, and P=10.5 W were obtained at the MPP from the V-I characteristic curve of the TEG.