• Title/Summary/Keyword: TcB

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Temperature Compensated Hall-Effect Power IC for Brushless Motor

  • Lee, Cheol-Woo;Jang, Kyung-Hee
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.74-77
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    • 2002
  • In this paper we present a novel temperature compensated Hall effect power IC for accurate operation of wide temperature and high current drive of the motor coil. In order to compensate the temperature dependence of Hall sensitivity with negative temperature coefficient(TC), the differential amplifier has the gain consisted of epi-layer resistor with positive TC. The material of Hall device and epi-resistor is epi-layer with the same mobility. The variation of Hall sensitivity is -38% at 150$^{\circ}C$ and 88% at - 40$^{\circ}C$. But the operating point(B$\sub$op/) and release point(B$\sub$RP/) of the Hall power IC are within ${\pm}$25%. The experimental results show very stable and accurate performance over wide temperature range of -40$^{\circ}C$ to 125$^{\circ}C$.

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Electrical Insulation Design and Experimental Results of a High-Tc Superconducting Cable (고온초전도 케이블의 전기절연 설계 및 시험평가)

  • Kwag, Dong-Soon;Cheon, Cheon-Gweon;Choi, Jae-Hyeong;Kim, Hae-Jong;Cho, Jeon-Wook;Kim, Sang-Hyun
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.55 no.12
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    • pp.640-645
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    • 2006
  • A 22.9kV/50MVA class high temperature superconducting(HTS) power cable system was developed in Korea. For the optimization of electrical insulation design for a HTS cable, it is necessary to investigate the ac breakdown impulse breakdown and partial discharge inception stress of the liquid nitrogen/laminated polypropylene paper(LPP) composite insulation system. They were used to insulation design of the model cable for a 22.9kV class HTS power cable and the model cable was manufactured. The insulation test of the manufactured model cable was evaluated in various conditions and was satisfied standard technical specification in Korea. Base on these experimental data, the single and 3 phase HTS cable of a prototype were manufactured and verified.

Generalization of Quantification for PLS Correlation

  • Yi, Seong-Keun;Huh, Myung-Hoe
    • The Korean Journal of Applied Statistics
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    • v.25 no.1
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    • pp.225-237
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    • 2012
  • This study proposes a quantification algorithm for a PLS method with several sets of variables. We called the quantification method for PLS with more than 2 sets of data a generalization. The basis of the quantification for PLS method is singular value decomposition. To derive the form of singular value decomposition in the data with more than 2 sets more easily, we used the constraint, $a^ta+b^tb+c^tc=3$ not $a^ta=1$, $b^tb=1$, and $c^tc=1$, for instance, in the case of 3 data sets. However, to prove that there is no difference, we showed it by the use of 2 data sets case because it is very complicate to prove with 3 data sets. The keys of the study are how to form the singular value decomposition and how to get the coordinates for the plots of variables and observations.

Characteristic Analysis and Experiments on Components of Low-Tc Power Supply (저온초전도전원장치의 시스템 특성해석 및 요소실험)

  • 윤용수;주민석;고태국
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.53 no.2
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    • pp.76-81
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    • 2004
  • This paper deals with characteristic analysis and experiments on components of low-Tc(LTS) power supply. A LTS power supply consists of two exciters, a rotor, a stator, and an LTS magnet. The power supply has eight rotating poles, which make rotational magnetic flux. These flux penetrate superconducting sheets and cause currents which charge an LTS load. In this experiment, a 25.8mH LTS magnet was used, and rotor revolutions from 30 to 300rpm were used. In order to measure the pumping-current with respect to the magnet flux changes, a hall sensor was installed at the center of the LTS magnet. The experimental observations have been compared with the theoretical predictions. In this experiment, the pumping-current has reached about 372A.

Electrical and Piezoelectric Properties on the Piezoceramics PZT Substituted for B-Sites (압전 세라믹(PZT)의 B-Site 치환에 따른 전기 및 압전 특성)

  • 이수호;박준범;사공건
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1992.05a
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    • pp.133-136
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    • 1992
  • Electrical resistivity and piezoelectric properties were investigated in Lead Zirconate-Titante(PZT) with Nb$_2$O$\sub$5/dopant, fabricated from conventional mixed-oxide powders and molten salt synthesis. The resistivity and electromechanical coupling factor(K$\sub$p/) were increased with increasing Nb content. The reason for increasing of the electrical resistivity below the Curie Temperature(TC). It is believed that the Curie Temperature(Tc). It is believed that the p-type electrical conduction in PZT is due to lead vacancies. The electromechanical coupling factor(K$\sub$p/) and piezoelectric constant d$\sub$33/ were improved. This behavior can be explained as a compensation effect and Nb$\^$5+/ can serve as a donar and contribute electrons to the conduction process. As a result, the optimized Nb$_2$O$\sub$5/ dopants on the PZT specimens were 0.75 wt%.

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Implementation of an Ethernet Adapter for the G-PON TC Layer (G-PON TC 계층을 위한 이더넷 정합기의 구현)

  • Chung, Hae;Ahn, Eu-Kwang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.5B
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    • pp.429-436
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    • 2011
  • The G-PON is an efficient solution to implement the FTTH and have GEM frame to accomodate various protocols like Ethernet frames, IP packets, and TDM signals. Above all, the Ethernet is one of the most widely used 2nd layer protocol in the campus, the subscriber access, and the carrier service. So G-PON system has to provide an Ethernet interface with top priority. In this paper, we implement a gigabit Ethernet adapter based on Ethernet over GEM in the ITU-T G.984.3 to accommodate Ethernet protocol in the G-PON TC chip. The adapter maps each Ethernet frame to a single or multiple GEM frames and has several functions including generation of the GEM header, encapsulation of frames and the SAR. In particular, the adapter have converter (LUT) MAC address to port-ID which is a key to identify logical connections though it is not defined in specification but important. We implement the adapter with a FPGA and verify the functions of segmentation and reassembling, MAC address learning, and throughput with the logic analyzer and the Ethernet analyzer.

Generation of transposon insertion mutants from type A Pasteurella multocida

  • Choi, Keum-hwa;Maheswaran, Samuel K.
    • Korean Journal of Veterinary Research
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    • v.39 no.2
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    • pp.327-337
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    • 1999
  • The transposon TnphoA was used to generate avirulent mutants from a type A Pasteurella multocida. A suicide vector plasmid pRT733 carrying TnphoA, having the kanamycin resistant gene and harbored in Escherichia coli K-12 strain SM10(${\lambda}pir$), was mated with streptomycin resistant P. multocida P-1059 strain as recipient. This resulted in the generation of two TnphoA insertion mutants (transconjugants, tc95-a and tc95-b) which were resistant both to kanamycin ($Km^{R}$) and streptomycin ($Sm^{R}$), secreted alkaline phosphatase, and were avirulent to turkeys. Southern blot hybridization using two probes derived from internal fragments of TnphoA, confirmed the insertion of TnphoA into 12.9kb or 13.7kb DNA fragment from the EcoRV digested genomic fragments of transconjugants. The two transconjugants, tc95-a and tc95-b, were distinguishable from their parent strains by differences in ribotypes, and outer membrane protein profiles. TnphoA insertion in both transconjugants also resulted in constitutive expression of a 33Kd iron regulated outer membrane protein (IROMP). The gene encoding $Sm^{R}$ was also located within the same 12.9kb EcoRV genomic fragment from both transconjugants. Furthermore, our finding that the recipient P. multocida P-1059 $Sm^{R}$ strain and both transconjugants were avirulent to turkeys suggest that the either 12.9kb or 13.7kb genomic DNA contains the virulence gene and speculate that the presence of $Sm^{R}$ gene or TnphoA insertion may be responsible for regulating and inactivating the gene(s) encoding virulence in P. multocida.

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A Design of TC layer Controller for ATM-PON OLT (ATM-PON OLT TC 계층 처리기 설계)

  • 이석훈;채종억;유태환;김봉태;김재근;김대영
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.6B
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    • pp.1059-1067
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    • 1999
  • In this paper characteristics of ATM-PON is described and a TC layer controller for ATM-PON OLT is designed. This paper proposes an algorithm of economically controlling the grant information written by CPU to dynamically allocate the upstream bandwidth on the PON among the ONUs in a fair way and of encrypting the downstream data using a lower standard of encryption, termed data churning, which is used to distinguish it from existing transmission system scramblers and higher layer encryption methods. This paper also proposes a method of allocating churning-related message into the PLOAM cell in order to synchronously change the churning key between the OLT and the ONU.

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Aldose reductase inhibitory activity and anti catraract potential of some traditionally acclaimed antidiabetic medicinal plants

  • Patel, Mayurkumar B;Mishra, Shrihari M
    • Advances in Traditional Medicine
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    • v.9 no.3
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    • pp.245-251
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    • 2009
  • Aldose reductase (AR) has been reported to play an important role in sugar-induced cataract. In the present study, the AR inhibitory activity of Enicostemma hyssopifolium (EH), Gymnema sylvestre, Eclipta alba, and Tinospora cordifolia (TC) were studied along with their effect on sugar-induced cataractogenic changes in sheep lenses in vitro. AR inhibitory activity of the aqueous extracts of plants and their anticataract potentials were evaluated in vitro in sheep lenses, considering the activity of normal sheep lenses as 100%. The concentration of the plant extract that showed maximum activity was selected to further study its effect on galactose-induced polyol accumulation in vitro. The $IC_50$ values of EH and TC were calculated to be 102 and 85 ${\mu}g$/ml, respectively. EH showed a significant inhibition (61.3%) in polyol accumulation followed by TC (53.1%). EH and TC possesses a significant anticataract activity in vitro and its anticataract potential could be related with its AR inhibitory effect.

Study on (n,p) reactions of 58Ni, 99Tc, 99Ru, 131Xe, 133Cs and 186Os radioisotopes used in medicine

  • Hallo M. Abdullah;Ali H. Ahmed
    • Nuclear Engineering and Technology
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    • v.55 no.1
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    • pp.304-309
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    • 2023
  • In the last decade, nuclear medicine appears to be a good choice of medicine. 58Co, 99Mo, 99Tc, 99Re, 133Xe and 186Re are very important radionuclides for nuclear medicine. In this study, the excitation functions of 58Ni (n, p) 58Co, 99Tc (n, p) 99Mo, 99Ru (n, p) 99Tc, 131Xe (n, p) 131I, 133Cs (n, p) 133Xe and 186Os (n, p) 186Re nuclear reactions were calculated at neutron energies between 1 and 20 MeV using TALYS 1.95 and EMPIRE 3.2 nuclear codes. Furthermore, the cross sections were calculated with the empirical formula derived in our past study at 14-15 MeV. The obtained results were compared with the measured values in EXFOR library, and with the evaluated data of (JENDL-4.0/HE, JEFF-3.3, TENDL-2019, ENDF/B-VIII.0, IRDFF-II, JENDL/ImPACT-18). The results are in good agreement with those of the evaluated data libraries and experimental results and indicates that these radioisotopes can be produced by smaller cyclotrons.