• The Transactions of the Korean Institute of Power Electronics
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• 제23권2호
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• pp.101-105
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• 2018

Shortage of electric power occurs frequently along with increased electric power demand. ESS is a precaution to solve this issue. Household ESS has a capacity of approximately 3 kW/7 kWh. Household ESS batteries are typically designed with nominal voltages between 40 and 50 V. To connect household ESS with a 220 V AC system, low battery voltages in power conditioning system (PCS) should be boosted. To boost low battery voltage and match it with AC grid voltage, the use of a transformer for a commercial frequency can be considered. To attenuate switching harmonics of the household single-phase ESS-PCS, LC filter can be installed in two positions: on the primary side or on the secondary side of a transformer. A method has been used generally in single-phase inverters for the ESS-PCS. In another method, however, the output efficiency of the ESS-PCS may be decreased. Parasitic components of the transformer can affect voltage losses, when the square wave with the switching frequency in the ESS-PCS is passed through the transformer windings. In this work, the characteristics of the transformer according to the position of an LC filter are investigated for household single-phase ESS-PCS.

• Proceedings of the KIEE Conference
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1526-1528
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• 1999

In this papaer, 7-segment was implemented using AC powder EL. ZnS:Cu and $BaTiO_3$ was used as a phosphor and dielectric respectively. The preparation of phosphor and dielectic layer was performed with screen printing. The implemented system of 7-segment was divided as following; EL display. driving circuit. software for driving. The properties of fabricated devices was measured with EL spectrum. brightness and J-V.

• Journal of Magnetics
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• 제10권3호
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• pp.84-88
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• 2005

Nanoparticles $Ni_{0.7}Zn_{0.3}Fe_2O_4$ is fabricated by a sol-gel method. The magnetic and structural properties of powders were investigated with XRD, SEM, $M\ddot{o}ssbauer$ spectroscopy, and VSM. $Ni_{0.7}Zn_{0.3}Fe_2O_4$ powders annealed at $300^{\circ}C$ have a spinel structure and behaved superparamagnetically. The estimated size of $Ni_{0.7}Zn_{0.3}Fe_2O_4$ nanoparticle is about 11 nm. $Ni_{0.7}Zn_{0.3}Fe_2O_4$ annealed at 400 and $500^{\circ}C$ has a typical spinel structure and is ferrimagnetic in nature. The isomer shifts indicate that the iron ions were ferric at the tetrahedral (A) and the octahedral (B). Blocking temperature $(T_B)\;of\;Ni_{0.7}Zn_{0.3}Fe_2O_4$ nanoparticle is about 260 K. The magnetic anisotropy constant of $Ni_{0.7}Zn_{0.3}Fe_2O_4$ annealed $300^{\circ}C$ were calculated to be $1.7X10^6\;ergs/cm^3$. Also, temperature of the sample increased up to $43^{\circ}C$ within 7 minutes under AC magnetic field of 7 MHz.

• Asian-Australasian Journal of Animal Sciences
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• 제21권8호
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• pp.1103-1108
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• 2008

An investigation to determine frequency and distribution of folate sensitive chromosomal fragile sites was carried out in a Pakistani breed of Lohi sheep to uncover fragile site phenomena. The means and standard errors of aberrant cell count (AC) and Number of aberrations (NoA) in Lohi sheep were $0.56{\pm}0.15$ and $0.59{\pm}0.16$ in the control cultures. FUdR treated cells showed significantly higher (p<0.001) AC and NoA means ($2.18{\pm}0.33$ and $2.65{\pm}0.50$). The sex comparison for the frequency of expression indicated that males had significantly higher number of aberrant cells and total number of aberrations in FUdR cultures than the female group in Lohi sheep. The comparison of control cultures was however, not significantly different between the two groups. The regression analysis of FUdR-induced chromosomal fragility data analysis of the fragility data predicted very low ${\beta}$ of 0.325 and 0.412 for AC and NoA respectively. Lohi chromosomes expressed lesions in only 7 and 24 bands in the control and FUdR cultures respectively. The total number of significantly fragile bands in the Lohi genome was only 4. The X-chromosome of the Lohi sheep was highly stable at $5{\mu}g/ml$ FUdR with no fragile sites. The sex comparison for the distribution of fragile sites across the Lohi genome did not reveal any noticeable differences.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제14권2호
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• pp.104-110
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• 2001

Structural, optical and electrical properties of Cd$_{1-x}$ Zn$_{x}$S films deposited by chemical bath deposition(CBD), which is a very attractive method for low-cost and large-area solar cells, are presented. Especially, in order to control more effectively the zinc component of the films, zinc acetate, which was used as the zinc source, was added in the reaction solution after preheating the reaction solution and the pH of the reaction solution decreased with increasing the concentration of zinc acetate. The films prepared after preheating and pH control had larger zinc component and higher optical band gap. The crystal structures of Cd$_{1-x}$ Zn$_{x}$S films was a wurtzite type with a preferential orientation of the (002) plane and the lattice constants of the films changed from the value for CdS to those for ZnS with increasing the mole ratio of the zinc acetate. The minimum lattice mismatch between Cd$_{1-x}$ Zn$_{x}$S and CdTe were 2.7% at the mole ratio of (ZnAc$_2$)/(CdAc$_2$+ZnAc$_2$)=0.4. As the more zinc substituted for Cd in the films, the optical transmittance improved, while the absorption edge shifted toward a shorterwavelength. the photoconductivity of the films was higher than the dark conductivity, while the ratio of those increased with increasing the mole ratio of zinc acetate. acetate.

• Tuberculosis and Respiratory Diseases
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• 제61권1호
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• pp.46-53
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• 2006

Background: Intra-abdominal hypertension (IAH) is defined as the presence of either an intra-abdominal pressure (IAP) ${\geq}12mmHg$ or an abdominal perfusion pressure (APP = mean arterial pressure - IAP) ${\leq}60mmHg$. Abdominal compartment syndrome (ACS) is defined as the presence of an IAP ${\geq}20mmHg$ together with organ failure. The purpose of this study was to investigate the prevalence of IAH and ACS on the day of admission and the effects of these maladies on the prognosis of critically ill patients in the ICU. Methods: At the day of admission to the ICU, the IAP was recorded by measuring the intravesicular pressure via a Foley catheter. The APACHE II and III scores were checked and SAPS II was also scored during the days the patients were in the ICU. The primary end point was the prevalence of IAH and ACS at the day of admission and the correlation between them with the 28-days mortality rate. The measurement of IAP continued until the 7th day or the day when the patient was transferred to the general ward before 7th day, unless the patient died or a Foley catheter was removed before 7th day. Patients were observed until death or the 28th day. Results: A total of 111 patients were enrolled. At the day of admission, the prevalence of IAH and ACS were 47.7% and 15.3%, respectively and the mean IAP was $15.1{\pm}8.5mmHg$. The rates of IAH for the survivor and the non-survivor groups were 56.5% and 71.4%, respectively, and these were not significantly different (p=0.593). Yet the rates of ACS between these two groups were significantly different (4/62, 6.5% vs. 13/49, 26.5%; Odds Ratio = 5.24, 95% CI = 1.58-17.30, p=0.004). Conclusion: In the present study, the prevalence of IAH was 47.7% and the prevalence of ACS was 15.3% on the day of admission. ACS was associated with a poor outcome for the critically ill patients in the ICU.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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• pp.259-262
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• 2003

In this paper, we designed and implemented digital wireless audio system with embedded RTOS using Bluetooth. Transmitter is consisted of a Settopbox, FIFO for interface block, Microprocessor(ARM7TDMI), UART driver and Bluetooth module. Receiver is consisted of a Microprocessor, AC-3 decoder, Bluetooth module and a Speaker with Amp. We programed Bluetooth protocal stack of HCI, L2CAP, and RFCOMM, so that Bluetooth module interacts with CPU.

• Journal of Microbiology and Biotechnology
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• 제17권8호
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• pp.1262-1270
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• 2007

Some hot springs located in the west of Turkey were investigated with respect to the presence of thermophilic microorganisms. Based on phenotyping characteristics and 16S rRNA gene sequence analysis, 16 of the isolates belonged to the genus Geobacillus and grew optimally at about $60^{\circ}C$ on nutrient agar. 16S rRNA gene sequence analysis showed that these isolates resembled Geobacillus species by ${\ge}97%$, but SDS-PAGE profiles of these 16 isolates differ from some of the other species of the genus Geobacillus. However, it is also known that analysis of 16S rRNA gene sequences may be insufficient to distinguish between some species. It is proposed that recN sequence comparisons could accurately measure genome similarities for the Geobacillus genus. Based on recN sequence analysis, isolates 11, IT3, and 12 are strains of G stearothermophilus; isolate 14.3 is a strain of G thermodenitrificans; isolates 9.1, IT4.1, and 4.5 are uncertain and it is required to make further analysis. The presence of xylanase and arabinofuranosidase activities, and their optimum temperature and pH were also investigated. These results showed that 7 of the strains have both xylanase and arabinofuranosidase activities, 4 of them has only xylanase, and the remaning 5 strains have neither of these activities. The isolates 9.1, 7.1, and 3.3 have the highest temperature optima ($80^{\circ}C$), and 7.2, 9.1, AO4, 9.2, and AO17 have the highest pH optima (pH 8) of xylanase. Isolates 7.2, AO4, AC15, and 12 have optimum arabinofuranosidase activities at $75^{\circ}C$, and only isolate AC15 has the lowest pH of 5.5.

• Polymer(Korea)
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• 제27권4호
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• pp.385-391
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• 2003

Lithium p-［Methoxyoligo(ethyleneoxy)］ benzenesulfonates (LiEOnBS) with different repeating unit of ethylene oxide were synthesized and were used for preparing gel-polymer electrolytes. The conductivities and lithium ion transference number were measured as a function of Li-salt concentration and repeating unit of ethylene oxide of the LiEOnBS. The maximum conductivity of the resulting gel-polymer electrolyte was found to be 4.89${\times}$10$\^$－4/ S/cm (LiEO7.3BS, 0.5 M) at 30$^{\circ}C$. The lithium ion transference number (t$\sub$Li$\sub$＋//) measurement were performed by means of the combination do polarization and ac impedance methods in gel-polymer electrolytes. Lithium ion transference number was measured to be in the range of 0.75∼0.92 for the LiEOnBS containing gel-polymer electrolytes. The maximum t$\sub$Li$\sub$＋// was obtained to be 0.92 for the 0.1 M LiEOnBS containing polymer electrolytes. The synthesized LiEOnBS showed single ion transport like characteristics when n was large than 3.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제16권1호
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• pp.27-34
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• 2002

In this paper, characteristics of the ac and dc flashover voltage in the horizontal air gap of a needle-needle electrode system were investigated when the combustion flame was present near the high-voltage electrode. In order to examine the flashover phenomena and the corona inception voltages caused by flame we measured the voltage and current waveforms when the corona and the flashover was occurred. We also observed, as increasing the applied voltages, the deflection or fluctuation phenomena in the shape of flames caused by the corona wind and the coulomb's force. As the results of an experimental investigation, we found that the reduction of flashover voltages, in comparison with the no-flame case, are 62.7[%] for k=1.0, 34.2[%] for h=5[cm], 27.3[%] for h=7[cm] and 21.4[%] for h=9[cm] when ac voltage is applied.