• Title/Summary/Keyword: V2C

Search Result 9,758, Processing Time 0.039 seconds

A Study on the Ontology Modeling by Analyzing RiC-CM v0.2 (RiC-CM v0.2 분석을 통한 온톨로지 모델링에 관한 연구)

  • Jeon, Ye Ji;Lee, Hyewon
    • Journal of Korean Society of Archives and Records Management
    • /
    • v.20 no.1
    • /
    • pp.139-158
    • /
    • 2020
  • This study is the first paper to introduce in the country the preview of RiC-CM v0.2, the standard for the description of records based on archival principles by the ICA in December 2019, and an early stage of research that considers how to apply it at archive management. This study was conducted as follows. First, this study compared and analyzed entities, attributes, and relations of RiC-CM v0.1 and v0.2, and extracted the characteristics of version 0.2. Second, this study tried to confirm the semantic structure of the archives by constructing the ontology modeling in consideration of the basic principle and the extracted characteristics of version 0.2, and built ontology modeling using Protégé. Finally, this study figured out the differences from version 0.1 through entering individuals into Protégé and examined how the characteristics of version 0.2 was represented by ontology.

The Effect of $V_2O_5$ Addition on the Microwave Dielectric Properties of $Zn_3Nb_2O_8$ Ceramics ($V_2O_5$ 첨가가 $Zn_3Nb_2O_8$ 마이크로파 유전체 특성에 미치는 영향)

  • Yun, Ho-Byung;Lee, Tae-Kun;Hwang, Yeon
    • Korean Journal of Crystallography
    • /
    • v.17 no.1
    • /
    • pp.24-32
    • /
    • 2006
  • The microwave dielectric properties of $Zn_3Nb_2O_8\;with\;V_2O_5$ addition were investigated. The addition of $V_2O_5$ enhanced the sinterability of $Zn_3Nb_2O_8$, which resulted in high density of $Zn_3Nb_2O_8$ ceramic greater than 95% of the theoretical value when sintered at $900^{\circ}C$ for 4 hours. X-ray diffraction analysis of sintered $Zn_3Nb_2O_8$ ceramic showed no second phase with $V_2O_5$ addition. Dielectric permittivity(${\varepsilon}_r$) and quality factor($Q{\times}f$) varied with both density at different sintering temperature and $V_2O_5$ addition. Dielectric permittivity, quality factor and temperature coefficient($T_{cf}$) of the two mole of $V_2O_5\;added\;Zn_3Nb_2O_8$ that was sintered at $900^{\circ}C$ were 21.4, 40,000, $-54ppm/^{\circ}C$, respectively.

Some Characterizations of Catenary Rotation Surfaces

  • Kim, Dong-Soo;Kim, Young Ho;Yoon, Dae Won
    • Kyungpook Mathematical Journal
    • /
    • v.57 no.4
    • /
    • pp.667-676
    • /
    • 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.

Application of Thermotolerant Yeast at High Temperature in Jar-fermentor Scale.

  • Sohn, Ho-Yong;Kim, Young-Ho;Rhee, In-Koo
    • Journal of Microbiology and Biotechnology
    • /
    • v.4 no.4
    • /
    • pp.316-321
    • /
    • 1994
  • We investigated the possibility of industrial application and economit process of high temperature fermentation by thermotolerant alcohol producing yeasts as previously reported. From the 20% glucose media, the RA-74-2 produced 11.8% (v/v) ethanol at $32^{\circ}C$ (0.5% inoculum) and 10.6% (v/v) ethanol at $40^{\circ}C$ (3% inoculum), respectively. Also, 11.3% (v/v) ethanol was produced for 96 hours in the temperature-gradient fermentation. These results suggest that the RA-74-2 could isuccessfully be applied to save the cooling water and energy in industrial scale without re-investment or modification of established fermentation systems. When potato starch was used as the substrate for the RA-74-2, high temperature fermentation above $40^{\circ}C$ was more appropriate for industrial utilization because organic nitrogen was not necessary to economical fermentation. As the naked barley media just prior to industrial inoculation, taken from the Poongkuk alcohol industry Co., were used, 9.6% (v/v) ethanol was produced at $40^{\circ}C$ for 48 hours in jar-fermentor scale (actually, 9.5-9.8% (v/v) ethanol was produced at 30~$32^{\circ}C$ for 100 hours in industrial scale). The ethanol productivity was increased by the high glucoamylase activity as well as the high metabolic ratio at $40^{\circ}C$ Therefore, if the thermotolerant yeast RA-74-2 would be used in industrial scale, we could obtain a high productivity and saving of the cooling water and energy. Meanwhile, the RA-912 produced 6%(v/v) ethanol in 10% glucose media at $45^{\circ}C$ and showed the less ethanol-tolerance compared with industrial strains. As the produced alcohol was recovered by the vacuum evaporator at $45^{\circ}C$ in 15% glucose media, the final fermentation ratio was enhanced (76% of theoretical yields). This suggest that a hyperproductive process could be achieved by a continuous input of the substrate and continuous recovery of the product under vacuum in high cell-density culture.

  • PDF

Synthesis and Electrochemical Characteristics of Carbon added Li3V2(PO4)3 (탄소첨가한 Li3V2(PO4)3의 합성 및 전기화학적 특성)

  • Jo, Yeong-Im;Na, Byung-Ki
    • Journal of the Korean Electrochemical Society
    • /
    • v.15 no.2
    • /
    • pp.101-108
    • /
    • 2012
  • The purpose of this study was to improve the conductivity of $Li_3V_2(PO_4){_3}$ by adding carbon source so that the discharge rate and cyclic properties were improved. Glucose and CNT were added to $Li_3V_2(PO_4){_3}$ and the structure and electrochemical properties were studied. $Li_3V_2(PO_4){_3}$, $Li_3V_2(PO_4){_3}$/C and $Li_3V_2(PO_4){_3}$/CNT were synthesised by solid state reaction using hydrogen reduction method at 600, 700, 800, $900^{\circ}C$. The cathode materials were assembled to coin cell type 2032 with Lithium metal as a counter electrode. The coin cell was galvanostatically evaluated in the voltage range of 3.0~4.8 V.

Effects of V and C additions on the Thermal Expansion and Tensile Properties of a High Strength Invar Base Alloy (고강도 인바계 합금의 열팽창 및 인장 특성에 미치는 바나듐과 탄소 원소 첨가 영향)

  • Yun, A.C.;Yun, S.C.;Ha, T.K.;Song, J.H.;Lee, K.A.
    • Transactions of Materials Processing
    • /
    • v.24 no.1
    • /
    • pp.44-51
    • /
    • 2015
  • The current study seeks to examine the effects of V and C additions on the mechanical and low thermal expansion properties of a high strength invar base alloy. The base alloy (Fe-36%Ni-0.9%Co-2.75%Mo-0.7Cr-0.23Mn-0.17Si-0.3%C, wt.%) contains $Mo_2C$ carbides, which form as the main precipitate. In contrast, alloys with additions of 0.4%V+0.3%C (alloy A) or 0.4%V+0.45%C (alloy B) contain $Mo_2C$+[V, Mo]C carbides. The average thermal expansion coefficients of these high strength invar based alloys were measured in the range of $5.16{\sim}5.43{\mu}m/m{\cdot}^{\circ}C$ for temperatures of $15{\sim}230^{\circ}C$. Moreover, alloy B showed lower thermal expansion coefficient than the other alloys in this temperature range. For the mechanical properties, the [V, Mo]C improved hardness and strengths(Y.S. and T.S.) of the high strength invar base alloy. T.S.(tensile strength) and Y.S.(yield strength) of hot forged alloy B specimen were measured at 844.6MPa and 518.0MPa, respectively. The tensile fractography of alloy B exhibited a ductile transgranular fracture mode and voids were initiated between the [V, Mo]C particles and the matrix. Superior properties of high strength and low thermal expansion coefficient can be obtained by [V, Mo]C precipitation in alloy B with the addition of 0.4%V and 0.45%C.

$TiO_{2}-V_{2}O_{5}$ Thin Film Type Humidity Sensor Fabricated by Sol-Gel Method (Sol-Gel법에 의한 $TiO_{2}-V_{2}O_{5}$ 박막형 습도센서)

  • Lee, D.C.;You, D.H.
    • Journal of Sensor Science and Technology
    • /
    • v.4 no.3
    • /
    • pp.15-21
    • /
    • 1995
  • In this paper, $TiO_{2}-V_{2}O_{5}$ humidity sensors are fabricated by Sol-Gel method. For the establishment of optimum processing condition which is good humidity sensitive characteristics for specimens, their microstructures and crystalline-structures are analysed. Grain size increases with substitution rate of $V^{5+}$ on $Ti^{4+}$ site. From the analysis of XRD, $V^{5+}$ peak can't confirm with $V_{2}O_{5}$ rate. Their humidity sensitive characteristics is good at 1mol% of $V_{2}O_{5}$ rate and heat-treated at $700^{\circ}C$. The capacitance of specimens decreases with frequency.

  • PDF

Synthesis and Structures of $(NH_4)_{10}[Ni(H_2O)_5]_4[V_2P_2BO_{12}]_6{\cdot}nH_2O$ and $(NH_4)_{3.5}(C_3H_{12}N_2)_{3.5}[Ni(H_2O)_6]_{1.25}{[Ni(H_2O)_5]_2[V_2P_2BO_{12}]_6{\cdot}nH_2O$

  • Yun, Ho-Seop;Do, Jung-Hwan
    • Korean Journal of Crystallography
    • /
    • v.15 no.1
    • /
    • pp.35-39
    • /
    • 2004
  • Two new nickel vanadium borophosphate cluster compounds, $(NH_4)_{10}[Ni(H_2O)_5]_4[V_2P_2BO_{12}]_6{\cdot}nH_2O$ (1) and $(NH_4)_{3.5}(C_3H_{12}N_2)_{3.5}[Ni(H_2O)_6]_{1.25}{[Ni(H_2O)_5]_2[V_2P_2BO_{12}]_6{\cdot}nH_2O$ (2) have been synthesized and structurally characterized. Inter-diffusion methods were employed to prepare the compounds. The cluster anion $[(NH_4)\;{\supset}\;V_2P_2BO_{12}]_6$ is used as a building unit in the synthesis of new compounds containing $Ni(H_2O){^{2+}_5}$ in the presence of pyrazine and 1,3-diaminopropane. Compounds contain isolated cluster anions with general composition ${[Ni(H_2O)_5]_n[(NH_4)\;{\supset}\;V_2P_2BO_{12}]_6}^{-(17-2n)}$ (n = 2, 4). Crystal data: $(NH_4)_{10}[Ni(H_2O)_5]_4[V_2P_2BO_{12}]_6{\cdot}nH_2O$, monoclinic, space group C2/m (no. 12), a = 27.538(2) ${\AA}$, b = 20.366(2) ${\AA}$, c = 11.9614(9) ${\AA}$, ${\beta}$ = 112.131(1)$^{\circ}$, Z = 8; $(NH_4)_{3.5}(C_3H_{12}N_2)_b[Ni(H_2O)_6]_{3.5}{[Ni(H_2O)_5]_2[V_2P_2BO_{12}]_6{\cdot}nH_2O$, triclinic, space group P-1 (no. 2), a = 17.7668(9) ${\AA}$, b = 17.881(1) ${\AA}$, c = 20.668(1) ${\AA}$, ${\alpha}$ = 86.729(1)$^{\circ}$, ${\beta}$ \ 65.77(1)$^{\circ}$, ${\gamma}$ = 80.388(1)$^{\circ}$, Z = 2.

Excess Volumes of Aqueous Solutions of Nonionic Amphiphile 2-(2-Hexyloxyethoxy)ethanol (비이온 양친매성 분자 2-(2-Hexyloxyethoxy)ethanol 수용액의 과잉 부피)

  • Lee, Jungno;Hwang, Yoonmi;Kang, Minhee;Lim, Kyung-Hee
    • Journal of the Korean Applied Science and Technology
    • /
    • v.37 no.3
    • /
    • pp.516-525
    • /
    • 2020
  • The densities of aqueous solutions of the amphiphile 2-(2-hexyloxyethoxy)ethanol (C6E2) were measured at 279.15 K and 282.15 K by vibrating-tube densitometry. Then using the density data of the binary C6E2 (1)/water(2) system, the excess volumes and partial molar volumes were determined at various compositions. Excess volume VE exhibits negative deviation for the whole region of composition, which implies relatively stronger attraction between molecules. At the C6E2 mole fraction of around 0.45, VE was at its minimum. Partial molar volume ${\bar{V}}_1$ increases monotonously with the mole fraction x1(=x) and ${\bar{V}}_2$ decreases with x. Any particular point in ${\bar{V}}_1$ and ${\bar{V}}_2$, which may point to molecular association, was unobserved.

The Four Color Algorithm (4-색 알고리즘)

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
    • /
    • v.18 no.5
    • /
    • pp.113-120
    • /
    • 2013
  • This paper proposes an algorithm that proves an NP-complete 4-color theorem by employing a linear time complexity where $O(n)$. The proposed algorithm accurately halves the vertex set V of the graph $G=(V_1,E_1)$ into the Maximum Independent Set (MIS) $\bar{C_1}$ and the Minimum Vertex Cover Set $C_1$. It then assigns the first color to $\bar{C_1}$ and the second to $\bar{C_2}$, which, along with $C_2$, is halved from the connected graph $G=(V_2,E_2)$, a reduced set of the remaining vertices. Subsequently, the third color is assigned to $\bar{C_3}$, which, along with $C_3$, is halved from the connected graph $G=(V_3,E_3)$, a further reduced set of the remaining vertices. Lastly, denoting $C_3$ as $\bar{C_4}$, the algorithm assigns the forth color to $\bar{C_4}$. The algorithm has successfully obtained the chromatic number ${\chi}(G)=4$ with 100% probability, when applied to two actual map and two planar graphs. The proposed "four color algorithm", therefore, could be employed as a general algorithm to determine four-color for planar graphs.