• Title/Summary/Keyword: V2V

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Development of 11,000V & 13,800V Medium Voltage Inverter using H-Bridge Multilevel (H-브릿지 멀티레벨을 적용한 11,000V & 13,800V 고압인버터 개발)

  • Park, Young-Min;Kim, Jong-Cheol;Cho, Sung-Joon
    • Proceedings of the KIPE Conference
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    • 2016.07a
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    • pp.415-416
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    • 2016
  • 본 논문은 입출력 전력품질이 우수하고 전압별 시리즈화가 용이한 Cascaded H-브릿지 멀티레벨 전력 회로를 적용한 고압 대용량 전동기 구동용 11,000V / 13,800V 고압인버터 개발에 관하여 기술하였다. 기존에 개발된 3,300V/200kVA - 6,600V/8,000kVA 고압인버터의 단상 인버터로 구성된 개별 파워 셀 전압 증대, 파워 셀의 직렬 갯수 추가, 입력 위상 전이 다권선 변압기 2차 권선수 확장, 그리고 분산 제어 기능을 확대하는 방식을 적용하여 전압을 증가시켰다. 실용량 제품의 제작 (11,000V/1,000kVA, 13,800V/2,400kVA) 및 실험을 통하여 개발된 11,000V/13,800V 고압인버터의 성능을 확인하였다.

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Some Characterizations of Catenary Rotation Surfaces

  • Kim, Dong-Soo;Kim, Young Ho;Yoon, Dae Won
    • Kyungpook Mathematical Journal
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    • v.57 no.4
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    • pp.667-676
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    • 2017
  • We study the positive $C^1$ function z = f(x, y) defined on the plane ${\mathbb{R}}^2$. For a rectangular domain $[a,b]{\times}[c,d]{\subset}{\mathbb{R}}^2$, we consider the volume V and the surface area S of the graph of z = f(x, y) over the domain. We also denote by (${\bar{x}}_V,\;{\bar{y}}_V,\;{\bar{z}}_V$) and (${\bar{x}}_S,\;{\bar{y}}_S,\;{\bar{z}}_S$) the geometric centroid of the volume under the graph of z = f(x, y) and the centroid of the graph itself defined on the rectangular domain, respectively. In this paper, first we show that among nonconstant $C^2$ functions with isolated singularities, S = kV, $k{\in}{\mathbb{R}}$ characterizes the family of catenary rotation surfaces f(x, y) = k cosh(r/k), $r={\mid}(x,y){\mid}$. Next, we show that one of $({\bar{x}}_S,\;{\bar{y}}_S)=({\bar{x}}_V,\;{\bar{y}}_V)$, $({\bar{x}}_S,\;{\bar{z}}_S)=({\bar{x}}_V,\;2{\bar{z}}_V)$ and $({\bar{y}}_S,\;{\bar{z}}_S)=({\bar{y}}_V,\;2{\bar{z}}_V)$ characterizes the family of catenary rotation surfaces among nonconstant $C^2$ functions with isolated singularities.

Computational analysis of SARS-CoV-2, SARS-CoV, and MERS-CoV genome using MEGA

  • Sohpal, Vipan Kumar
    • Genomics & Informatics
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    • v.18 no.3
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    • pp.30.1-30.7
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    • 2020
  • The novel coronavirus pandemic that has originated from China and spread throughout the world in three months. Genome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) predecessor, severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) play an important role in understanding the concept of genetic variation. In this paper, the genomic data accessed from National Center for Biotechnology Information (NCBI) through Molecular Evolutionary Genetic Analysis (MEGA) for statistical analysis. Firstly, the Bayesian information criterion (BIC) and Akaike information criterion (AICc) are used to evaluate the best substitution pattern. Secondly, the maximum likelihood method used to estimate of transition/transversions (R) through Kimura-2, Tamura-3, Hasegawa-Kishino-Yano, and Tamura-Nei nucleotide substitutions model. Thirdly and finally nucleotide frequencies computed based on genomic data of NCBI. The results indicate that general times reversible model has the lowest BIC and AICc score 347,394 and 347,287, respectively. The transition/transversions bias for nucleotide substitutions models varies from 0.56 to 0.59 in MEGA output. The average nitrogenous bases frequency of U, C, A, and G are 31.74, 19.48, 28.04, and 20.74, respectively in percentages. Overall the genomic data analysis of SARS-CoV-2, SARS-CoV, and MERS-CoV highlights the close genetic relationship.

Development of environmentally friendly inorganic fluorescent pigments, A3V5O14 (A = K and Rb) and Cs2V4O11: Crystal structure, optical and color properties (친환경 무기 형광 안료 A3V5O14 (A = K and Rb) and Cs2V4O11 개발: 결정구조, 광학적 특성 및 착색 특성)

  • Jeong, Gyu Jin;Kim, Jin Ho;Lee, Younki;Hwang, Jonghee;Toda, Kenji;Bae, Byoungseo;Kim, Sun Woog
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.30 no.2
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    • pp.47-54
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    • 2020
  • To develop the bright-vivid red- and yellow-inorganic fluorescent pigments with high luminescence properties, A3V5O14 (A = K and Rb) and Cs2V4O11 inorganic pigments were synthesized by a water assisted solid state reaction (WASSR) method and a conventional solid state reaction method. Although impurity peaks corresponding to the AVO3 and AV3O8 (A = K, Rb, and Cs) were observed in all samples prepared, the trigonal structure A3V5O14 (A = K and Rb) and orthorhombic structure Cs2V4O11 were successfully obtained as a main phase. These inorganic pigments showed the broad absorption band (under 550 nm) originated from CT transitions of VO4 polyhedron, and the strong broad red- and green-emission bands due to 3T21A1 and 3T11A1 transitions of the [VO4]3- group. The A3V5O14 (A = K and Rb) and Cs2V4O11 pigments showed a bright-vivid red- and yellow-body color, where the a* values of the A3V5O14 (A = K and Rb) were +35.5 and +45.9, respectively, and b* value of Cs2V4O11 pigments was +50.3. The L* values of the A3V5O14 (A = K and Rb) and Cs2V4O11 inorganic pigments were over +45. These results indicate that the A3V5O14 (A = K and Rb) and Cs2V4O11 inorganic pigments could be an attractive candidate as a bright-vivid red- and yellow inorganic pigments.

Growth and Yield Responses of Soybean to Overhead Flooding Duration at Four Growth Stages (관수시간에 따른 콩의 생육 및 수량반응)

  • 박경열;이종형;조영철
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.1
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    • pp.92-97
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    • 1995
  • The objective of this study is to investigate the growth characters of overhead flooded soybean plants at four growth stage. Overhead flooding treatments were applied at the vegetative growth stage ($V_3,\;V_6$) and the reproductive stage ($R_2,\;R_4$) for 6.12.24 hrs, respectively. Yield and yield components were more decreased as the overhead flooding duration was longer and the growth stage was later. Yield was not reduced significantly in soybean plants flooded at $V_3$ stage regardless of flooding duration, and flooded 6 or 12 hrs at $V_6$ stage. When compared to the control, 27 to 36% of yield reduction was observed in soybean plants flooded for 24 hrs at $V_6$ stage, 6 or 12 hrs at $R_2$ stage, and 6 hrs at $R_4$ stage. And 43%, 53% and 66% of yield were reduced through the flooding treatment for 24 hrs at $R_2$ stage 12 hrs and 24 hrs at $R_4$ stage, respectively. So yield reduction was higher in overhead flooded soybean plants at the reproductive stage than that at the vegetative growth stage.

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A Study on the Stability Control Method of Soft and Polluted Silt Soils (연약한 실트지반과 오염된 실트지반의 안정관리 방법에 관한 연구)

  • Ahn, Jong-Pil;Park, Sang-Bum
    • Journal of the Korean Geotechnical Society
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    • v.24 no.6
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    • pp.5-16
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    • 2008
  • This study investigated the existing theoretical backgrounds in order to examine the stability control method of lateral flow caused by the Plasticity of soils when unsymmetrical surcharge works on polluted soils and then compared and analyzed the results measured through model tests. Ultimate bearing power of ML and $ML_{p1}$ and $ML_{p2}$ obtained at surcharge(q)-settlement$(S_v)$ curve showed similar trends to ultimate bearing power obtained from control chart of deflection $(S_v-Y_m)$ by Tominaga.Hashimoto, that of $S_v-(Y_m/S_v)$ by Matsuo.Kawamura and that of $(q/Y_m)-q$ by Shibata.Sekiguchi and so it is considered that it has no problem in actual applicability. ${S_v-(Y_m/S_v)}$ of control chart of $ML_{p1}$ by Matsuo.Kawamura showed smaller value than ultimate bearing capacity value from surcharge-settlement curve $(q-S_v)$. Expression of ML of fracture baseline at stability control charge by Matsuo Kawamura is ${S_v=3.21exp}\{-0.48(Y_m/S_v)\}$ and expression of $ML_{p1}$ is ${S_v=3.26exp}\{-0.96(Y_m/S_v)\}$ and expression of $ML_{p2}$ is ${S_v=6.33exp}\{-0.45(Y_m/S_v)\}$.

MULTIPLICITY RESULTS FOR THE WAVE SYSTEM USING THE LINKING THEOREM

  • Nam, Hyewon
    • Korean Journal of Mathematics
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    • v.21 no.2
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    • pp.203-212
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    • 2013
  • We investigate the existence of solutions of the one-dimensional wave system $$u_{tt}-u_{xx}+{\mu}g(u+v)=f(u+v)\;\;in\;(-\frac{\pi}{2},\frac{\pi}{2}){\times}R,\\v_{tt}-v_{xx}+{\nu}g(u+v)=f(u+v)\;\;in\;(-\frac{\pi}{2},\frac{\pi}{2}){\times}R,$$ with Dirichlet boundary condition. We find them by applying linking inequlaities.

BVRI Standardization of the CCD Photometric System of Sobaeksan Optical Astronomy Observatory (소백산 천문대 CCD 측광계의 BVRI 표준화)

  • Jeong, Jang-Hae;Kim, Chun-Hwey;Lee, Yong-Sam
    • Journal of Astronomy and Space Sciences
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    • v.25 no.2
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    • pp.87-100
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    • 2008
  • A total of 792 CCD images of V523 Cas were obtained on four nights of Jan. 2003 with the bvri CCD photometric system attached to a 61cm reflector of Sobaeksan Optical Astronomy Observatory (SOAO). The 17 standard stars in the images were used to establish transformation relations between our bvri system and the standard Johnson-Cousins BVRI system. We derived the tentative equations of transformation between two photometric systems as follows; V=v-0.0689(B-V)+0.0063, B-V=1.3197(b-v)-0.1733, V-R=0.9210(v-r)-0.1309, R-I=0.8892(r-i)-0.1055. Using these equations standard V magnitudes and their color indexes (B-V, V-R, R-I) for 57 stars in the field of the image were determined.

Charge/discharge Properties of $V_2O_5$-AC Composite for Supercapacitor (Supercapacitor용 $V_2O_5$-AC Composite의 충방전 특성)

  • 김명산;김종욱;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.366-369
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    • 1999
  • The purpose of this study is to research and develop V2Os-AC(activated carbon) composite electrode for supercapacitor. Supaercapacitor cell of V2Os-AC composite electrode with 25P70FLiCIO$_{4}$/PC$_{10}$/EC$_{10}$ polymer electrolyte bring out good capacitor Performance below 3V. The discharge capacitance of V2Os-AC(30:70) composite with 70wt.% AC in 1st and 200th cycles was 9.6 and 8.2 F/g at current density of 1m7/cm2. The capacitance of V$_2$O$_{5}$-AC composite with 70wt.% AC capacitor was larger than that of others. The coulombic efficiency of supercapacitor at discharge process of 1 and 200 cycles were 96 and 100%, respectively. V$_2$O$_{5}$-AC composite supercapacitor with 70wt.% AC content showed good capacitance and stability with cycling.ing.ing.

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Temperature Dependence of the Rate Constants of the VV Energy Exchange for N$_2$(v=1)+O$_2$(v=0)$\rightarrow$N$_2$(v=0)+O$_2$(v=1)

  • Ree, Jong-Baik;Chung, Keun-Ho;Kim, Hae-Jin
    • Bulletin of the Korean Chemical Society
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    • v.7 no.3
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    • pp.241-245
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    • 1986
  • The vibration-vibration energy exchange of $N_2(v=1)+O_2(v=0){\to}N_2(v=0)+O_2(v=1)$ has been investigated, in particular, at low temperatures. The energy exchange rate constants are calculated by use of the solution of the time-dependent Schrodinger equation with the interaction potential of the colliding molecule as a perturbation term. The predicted rate constants are significantly agree with a experimental values in the range of 295∼$90^{\circ}K$. The consideration of the VV-VT coupling decreases the predicted pure VV energy exchange value by a factor of ∼2. When the collision frequency correction is introduced, the VV-VT rate constant is consistent with the observed value in the liquid phase. The consideration of the population of the rotational energy level increases the VV-VT value significantly.