• 제목/요약/키워드: $E_b/N_t$

검색결과 468건 처리시간 0.028초

Reduction of series transformer voltage variation of voltage disturbance generator (전압변동 발생기의 직렬변압기에 의한 전압변동 개선)

  • Nho, E.C.;Lee, Y.H.;Min, B.H.;Kim, I.D.;Chun, T.W.;Kim, H.G.;Choi, N.S.
    • Proceedings of the KIPE Conference
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    • 전력전자학회 2007년도 추계학술대회 논문집
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    • pp.218-220
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    • 2007
  • A new 3-phase voltage disturbance generator is proposed. The voltage drop of the conventional generator in normal mode can be reduced significantly. The output voltage of the proposed generator is constant in normal mode and the efficiency of the series transformer is improved. The proposed generator has good feature of simple structure, cost effective implementation, high reliability, high efficiency, and easy control. The usefulness of the scheme is verified through simulation and experiments.

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Calculation of Reactor Pressure Vessel Fluence Using TORT Code

  • Shin, Chul-Ho;Kim, Jong kyung
    • Proceedings of the Korean Nuclear Society Conference
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    • 한국원자력학회 1998년도 춘계학술발표회논문집(2)
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    • pp.771-776
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    • 1998
  • TORT is employed for fast neutron fluence calculation at the reactor pressure vessel. KORI Unit 1 reactor at cycle 1 is modeled for this calculation. Three-dimensional cycle averaged assembly power distributions for KORI Vnit 1 at cycle 1 are calculated by using the core physics code, NESTLE 5.0. The root mean square error is within 4.3% compared with NDR (Nuclear Design Report) far all burnup steps. The C/E (Calculated/Experimental) values for the in-vessel dosimeters distribute between 0.98 and 1.36. The most updated cross-section library. BUGLE-96 based on ENDF/B-VI is used for the neutron fluence calculation. The makimum fast neutron nun calculated on reactor pressure vessel for KORI Unit 1 operated for 411.41 effgctive full power days is 1.784x10$^{18}$ n/$\textrm{cm}^2$. The position of the maximum neutron fluence in RPV wall 1/4 T is nearby 60cm below the midplane at zero degree.

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Improvement of output voltage drop characteristic for 3-phase voltage disturbance generator (3상 전압변동 발생기의 출력전압강하 특성 개선)

  • Lee, Y.H.;Min, B.H.;Park, S.D.;Nho, E.C.;Kim, I.D.;Chum, T.W.;Kim, H.G.;Choi, N.S.
    • Proceedings of the KIPE Conference
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    • 전력전자학회 2007년도 하계학술대회 논문집
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    • pp.120-122
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    • 2007
  • A new power quality disturbance generator is proposed. The proposed scheme overcomes the problem of voltage drop of the conventional generator in normal mode. Therefore, the output voltage of the proposed generator is constant in normal mode and the efficiency of the series transformer is improved. The proposed generator has good feature of simple structure, cost effective implementation, high reliability and easy control. The usefulness of the scheme is verified through simulation and experiments.

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A Study on the Low-Priority Symbol Transmission in AT-DMB System

  • Erke, Li;Kim, Hanjong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 한국해양정보통신학회 2009년도 추계학술대회
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    • pp.755-757
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    • 2009
  • Since the research of advanced terrestrial digital multimedia broadcasting system is still in progress, and in our previous paper, in which we introduced how to combine one conventional transmitted symbol with two additional bits to form a new symbol transmission, the bit error performance of LP bits is not realizable, because even we implemented the turbo code to protect the LP bits transmission, to obtain a certain good bit error probability, the value of $E_b/N_0$ cost highly. In this paper, we modified the composition of low-priority symbol and high-priority symbol, and through the system presented in previous paper we get a better simulation result of the LP symbol transmission.

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Virus-resistant and susceptible transgenic Nicotiana benthamiana plants expressing coat protein gene of Zochini green mottle mosaic virus for LMO safety assessment

  • Park, M.H.;B.E. Min;K.H. Ryu
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.146.1-146
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    • 2003
  • Transgenic Nicotiana benthmiana plants harboring and expressing coat protein (CP) gene of Zucchini green mottle mosaic virus (ZGMMV) were generated for both virus-resistant screening and complementation analysis of related viruses and environmental safety assessment (SA) of living modified organism (LMO) purposes. Transformation of leaf disc of N. benthamiana was performed using Agrobacterium-mediated method and the pZGCPPGA748 containing the ZGMMV CP and NPTII genes. Two kinds of transgenic homozygous groups, virus-resistant and -susceptible lines, were obtained by screening of challenging homologous virus for T1 generations. Complementation of CP-deficient related virus was analyzed using the susceptible line of ZGMMV. These two pathologically different lines can be useful for host-virus interactions and LMO environmental SA.

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Effect of Nonstarch Polysaccharide-Rich By-Product Diets on Nitrogen Excretion and Nitrogen Losses from Slurry of Growing-Finishing Pigs

  • Canh, T.T.;Verstegen, M.W.A.;Mui, N.B.;Aarnink, A.J.A.;Schrama, J.W.;Van't Klooster, C.E.;Duong, N.K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제12권4호
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    • pp.573-578
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    • 1999
  • An experiment was conducted to investigate the effect of diet for growing-finishing pigs with high level of non-starch polysaccharides (NSP) from by-products on nitrogen excretion and nitrogen losses from slurry during storage. Sixteen commercial crossbred barrows of about 68 kg BW were randomly allotted to one of four diets. The control diet was formulated using tapioca and rice as basal energy sources. In the other diets, tapioca was replaced by either coconut expellar, rice bran or beer by-product. The diets differed mainly in the amount and compostition of NSP. After a 12-day adaptation period, urine and faeces were collected separately in metabolism cages for 9 days. Urine and faeces from the first four days were used to analyse the nitrogen partitioning. Urine and faeces from the last 5 days were mixed as slurry. The slurry was sampled at the end of the collection period and again after 30 days storage, to analyse for nitrogen to calculate the losses. Increasing dietary NSP reduced urinary nitrogen and nitrogen losses from the slurry during storage. The pigs fed the diet based on beer by-product excreted the most nitrogen via faeces and the least nitrogen via urine. Nitrogen losses from slurry of pigs fed the beer by-product were from 34 to 65% lower than from the other three diets. It is concluded that including NSP-rich by-products in the diet of growing-finishing pigs reduces urinary nitrogen excretion and nitrogen losses from slurry during storage.

일본의 과학 및 학술 정보 정책의 수립 과정과 실시 체제의 분석

  • 현규섭
    • Journal of the Korean Society for information Management
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    • 제5권1호
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    • pp.31-52
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    • 1988
  • The information policy in Japan have bccir growing rapldlr 111 recent vttars. \'arioi~s level of govc~riimerital organrzatlons, ir~bt~tution arid agrircics have undt~rtak~~rr iriforrnatiori polrcy 111 order to i r l - crease information flow toward tlie society in Japan. At tlie same trme, computerized library systems also h a w uridergoirc rapid expansion. NACSIS(National Ceriter for- Science Informat~on System) wl~icl~ was cstablisl~ed bv Mirristr> of Etlr~c~arion, Sc~ence arid Culture haw witnessed dramatic adv;rnces i r i promoting for corrstructiori of database so as to provide their 11rf'3r.mat1orr nu nationwide scale. T l r i h articlr inrroduccs tlie actr\rtle> and ~mplcmeritat~o~~ of it format in^^ pol~cy wl~i(~li taktas a place hy goverrirnrlit of Japar~ aid arraly~c,.; thi~ ~ I . O I . P S I of deciiioii maltiiig iri polit~cal procedures. So far as b:ast-A\~ari riatioris art, ~ . n r i v t ~ r ~ ~ , e.;pc,ciall\. Kr,rc.an a~rd Japair !rave ,imilar cultural and liistorical backjir. ourii1, ard could t)t. tliif most a p p r o p r i a t ~ ~ caac stlldh for political ~nq~lerncritat~orr. Thus the topic of this artrclc will be useful to r t ~ a l l ~ t . Ore, trail ur~d c r r o r prorex, iri iiiior.matior~ pnlic\ulcorner.

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Crystal Structure and Magnetic Properties of Sodium-Iron Phosphates NaFe0.9Mn0.1PO4 Cathode Material

  • Seo, Jae Yeon;Choi, Hyunkyung;Kim, Chul Sung;Lee, Young Bae
    • Journal of the Korean Physical Society
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    • 제73권12호
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    • pp.1863-1866
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    • 2018
  • The sodium-iron phosphate maricite-$NaFe_{0.9}Mn_{0.1}PO_4$ was synthesized using the ball mill method. The crystal structure and magnetic properties of the prepared materials were studied using X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and $M{\ddot{o}}ssbauer$ spectroscopy. Structural refinement of maricite-$NaFe_{0.9}Mn_{0.1}PO_4$ was analyzed using the FullProf program. From the XRD patterns, the crystal structure of maricite-$NaFe_{0.9}Mn_{0.1}PO_4$ was found to be orthorhombic with the space group Pmnb. The lattice parameters of maricite-$NaFe_{0.9}Mn_{0.1}PO_4$ are as follows: $a_0=6.866{\AA}$, $b_0=8.988{\AA}$, $c_0=5.047{\AA}$, and $V=311.544{\AA}^3$. Maricite-$NaFePO_4$ has an edge-sharing structure that consists of $FeO_6$ octahedral. Under an applied field of 100 Oe, the temperature dependences of zero-field-cooled (ZFC) and field-cooled (FC) curves were measured from 4.2 to 295 K. $M{\ddot{o}}ssbauer$ spectra were also recorded at various temperatures ranging from 4.2 to 295 K. We thus confirmed that the $N{\acute{e}}el$ temperature of $NaFe_{0.9}Mn_{0.1}PO_4$ ($T_N=14K$) was lower than that of maricite-$NaFePO_4$ ($T_N=15K$).

Photocurrent Study on the Splitting of the Valence Band and Growth of BaIn2Se4 epilayers by Hot Wall Epitaxy (Hot Wall Epitaxy(HWE)법에 의한 BaIn2Se4 에피레어 성장과 가전자대 갈라짐에 대한 광전류 연구)

  • Jeong, Junwoo;Lee, Kijeong;Jeong, Kyunga;Hong, Kwangjoon
    • Journal of Sensor Science and Technology
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    • 제23권2호
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    • pp.134-141
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    • 2014
  • A stoichiometric mixture of evaporating materials for $BaIn_2Se_4$ epilayers was prepared from horizontal electric furnace. To obtain the single crystal thin films, $BaIn_2Se_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $620^{\circ}C$ and $400^{\circ}C$, respectively. The crystalline structure of the epilayers was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $BaIn_2Se_4$ epilayers measured from Hall effect by van der Pauw method are $8.94{\times}10^{17}cm^{-3}$ and 343 $cm^2/vs$ at 293 K, respectively. The temperature dependence of the energy band gap of the $BaIn_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)$=2.6261 eV-$(4.9825{\times}10^{-3}eV/K)T^2/(T+558 K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $BaIn_2Se_4$ have been estimated to be 116 meV and 175.9 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $BaIn_2Se_4/GaAs$ epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_1-$, $B_1$-exciton for n = 1 and $C_{21}$-exciton peaks for n=21.

Growth and Optical Conductivity Properties for BaAl2Se4 Single Crystal Thin Film by Hot Wall Epitaxy (Hot Wall Epitaxy(HWE)법에 의한 BaAl2Se4 단결정 박막 성장과 광전도 특성)

  • Jeong, Junwoo;Lee, Kijung;Hong, Kwangjoon
    • Journal of Sensor Science and Technology
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    • 제24권6호
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    • pp.404-411
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    • 2015
  • A stoichiometric mixture of evaporating materials for $BaAl_2Se_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $BaAl_2Se_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $610^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $BaAl_2Se_4$ single crystal thin films measured from Hall effect by van der Pauw method are $8.29{\times}10^{-16}cm^{-3}$ and $278cm^2/vs$ at 293 K, respectively. The temperature dependence of the energy band gap of the $BaAl_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.4205eV-(4.3112{\times}10^{-4}eV/K)T^2/(T+232 K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $BaAl_2Se_4$ have been estimated to be 249.4 meV and 263.4 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $BaAl_2Se_4/GaAs$ epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-exciton for n =1 and $C_{31}$-exciton peaks for n=31.