• 설비공학논문집
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• 제25권3호
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• pp.143-149
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• 2013

In this work, nucleate pool boiling heat transfer coefficients (HTCs) of R134a and R1234yf are measured, on flat plain, 26 fpi low fin, Turbo-B, Turbo-C and Thermoexcel-E surfaces. All data are taken at the liquid pool temperature of $7^{\circ}C$, on a small square copper plate ($9.53mm{\times}9.53mm$), at heat fluxes from $10kW/m^2$ to $200kW/m^2$, with an interval of $10kW/m^2$. Test results show that nucleate boiling HTCs of all enhanced surfaces are greatly improved, as compared to that of a plain surface. Nucleate pool boiling HTCs of R1234yf are very similar to those of R134a, for the five surfaces tested.

• 한국자동차공학회논문집
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• 제18권1호
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• pp.74-85
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• 2010

In order to formulate the compounded polypropylene(C-PP) which is suitable to an automotive door trim panel, 9 sorts of properties were measured after manufacturing the C-PP using an extruder and an injection machine with polypropylene(PP), ethylene-octene rubber(EOR) and talc. Mixture design, especially extreme vertices design, in DOE with MINITAB - commercial software was used to analyze the data. The relations between each property and each component, for example, $y=0.00907222x_1+0.00870556x_2+0.0155722x_3$ for specific gravity, were found out by the regression analysis and the variance analysis. The optimized formulation of the C-PP for an automotive door trim panel was acquired at PP(77.6962), EOR(11.0238) and talc(10.2800) by use of the response optimizer(mixture) in MINITAB.

• 대한수학회보
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• 제31권1호
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• pp.105-113
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• 1994

In the course of study of dendroids, Czuba [3] introduced a notion of $R^{i}$ -continua which is a generalization of R-arc [1]. He showed a new class of non-contractible dendroids, namely of dendroids which contain an $R^{i}$ -continuum. Subsecequently Charatonik [2] attempted to extend the notion into hyperspace C(X) of metric continuum X. In so doing, there were some oversights in extending some of the results relating $R^{i}$ -continua of dendroids for metric continua. In fact, Proposition 1 in [2] is false (see example C below) and his proof of Theorem 6 in [2] is not correct (Take Example 4 in [4] with K = [e,e'] as an $R^{1}$-continuum of X and work it out. Then one seens that K not .mem. K as he claimed otherwise.). The aims of this paper are to introduce a notion of w-regular convergence which is weaker than 0-regular convergence and to prove that the w-regular convergence of a sequence {Xn}$^{\infty}$$_{n=1}$ to $X_{0}$ of subcontinua of a metric continuum X is a necessary and sufficient for the sequence {C( $X_{n}$)}$^{\infty}$$_{n=1}$ to converge to C( $X_{0}$ ), and also to prove that if a metric continuum X contains an $R^{i}$ -continuum with w-regular convergence, then the hyperspace C(X) of X contains $R^{i}$ -continuum.inuum.uum.

• 대한수의학회지
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• 제43권1호
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• pp.139-144
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• 2003

A chitinase cDNA named CHT1 was cloned from the hard tick, Haemaphysalis longicornis, and the enzymatic properties of its recombinant proteins were characterized. The CHT1 cDNA encodes 930 amino-acid (aa) residues including a 22 aa putative signal peptide, with the calculated molecular mass of the putative mature protein 104 kDa. The E coli-expressed rCHT1 exhibited weak chitinolytic activity against $4MU-(GlcNAc)_3$. The rCHT1 protein with higher activity was obtained using recombinant Autographa californica multiple nuclear polyhedrosis virus (AcMNPV), which expresses rCHT1 under polyhedrin promoter. These findings suggest that the rCHT1 expressed in baculovirus-mediated Sf 9 cells has a high activity than E coli-expressed rCHT1.

• 충청수학회지
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• 제30권1호
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• pp.77-102
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• 2017

As an analogy of $Poincar{\acute{e}}$ series in the space of modular forms, T. Ono associated a module $M_c/P_c$ for ${\gamma}=[c]{\in}H^1(G,R^{\times})$ where finite group G is acting on a ring R. $M_c/P_c$ is regarded as the 0-dimensional twisted Tate cohomology ${\hat{H}}^0(G,R^+)_{\gamma}$. In the case that G is the Galois group of a Galois extension K of a number field k and R is the ring of integers of K, the vanishing properties of $M_c/P_c$ are related to the ramification of K/k. We generalize this to arbitrary n-dimensional twisted cohomology of the ring of integers and obtain the extended version of theorems. Moreover, some explicit examples on quadratic and biquadratic number fields are given.

• Bulletin of the Korean Chemical Society
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• 제32권6호
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• pp.1921-1924
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• 2011

Nitrile-forming eliminations from $(E)-2,4,6-(NO_2)_3C_6H_2CH=NOC_6H_4-2-X-4-NO_2$ (1) promoted by $R_3NH/R_3NH^+$ in 70 mol % MeCN(aq) have been studied kinetically. When X = $NO_2$, the reactions exhibited second-order kinetics as well as Br$\"{o}$nsted ${\beta}$ = 0.63 and ${\mid}{\beta}_{lg}{\mid}$ = 0.34-0.46, and an E2 mechanism is evident. As the leaving group was made poorer (X = H, Cl, and $CF_3$), Br$\"{o}$nsted ${\beta}$ value increased from 0.63 to 0.85-0.89 without much change in the ${\mid}{\beta}_{lg}{\mid}$ value E2, indicating that structure of the transition state changed to an E1cb-like with extensive $C_{\beta}-H$ bond cleavage, significant negative charge development at the ${\beta}$-carbon, and limited $C_{\alpha}$-OAr bond cleavage.

• 대한수학회논문집
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• 제12권2호
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• pp.275-285
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• 1997

Let E be a uniformly convex Banach space with a uniformly G$\hat{a}teaux differentiable norm, C a nonempty closed convex subset of $E, T : C \to E$ a nonexpansive mapping, and Q a sunny nonexpansive retraction of E onto C. For $u \in C$ and $t \in (0,1)$, let $x_t$ be a unique fixed point of a contraction $R_t : C \to C$, defined by $R_tx = Q(tTx + (1-t)u), x \in C$. It is proved that if ${x_t}$ is bounded, then the strong $lim_{t\to1}x_t$ exists and belongs to the fixed point set of T. Furthermore, the strong convergence of ${x_t}$ in a reflexive and strictly convex Banach space with a uniformly G$\hat{a}$teaux differentiable norm is also given in case that the fixed point set of T is nonempty.

• E2M - 전기 전자와 첨단 소재
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• 제8권6호
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• pp.780-786
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• 1995

For the execution of RIETAN program adopting Rietveld Analysis Method, the sample superconductor is made according to the solid state synthesis method at 920.deg. C for 24hrs, and was examined for the optimization of parameters needed to analyze Rietveld method with the input of the measured pattern data after measuring the pattern resulted from the X-ray diffraction. It was proven that the lattice constant of the superconductor which was consisted of Pmmm orthorhombic crystal structure in the analyzed space group correspond to the presented theoretical lattice constant a=3.8887(8).angs., b=3.8238(4).angs., c=11.7079.angs.. Therefore, it was examined and confin-ned that the R factor, which was compensated after analyzing the structure of superconductor resulted from this experimented data with the computer simulation, was refined to $R_{wp}$=8.83[%], $R_{P}$=6.47[%], $R_{I}$=10.08[%], $R_{F}$=7.19[%], $R_{E}$=3.76[%]. On the basis of these experimental data, the significant parameter such as the scale factor(S) and the zero point shift(Z) and FWHM value(U,V,W) were optimized as follows; S=2.0827E-3, Z=0.2146, U=4.2761E-2, V=1.7983E-2, and W=2.6768E-2.2.2.2.2.2.

• 한국입자에어로졸학회지
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• 제15권1호
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• pp.1-13
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• 2019

Current desulfurization and denitrification technologies have reached a considerable level in terms of reduction efficiency. However, when compared with the simultaneous reduction technology, the individual reduction technologies have issues such as economic disadvantages due to the difficulty to scale-up apparatus, secondary pollution from wastewater/waste during the treatment process, requirement of large facilities for post-treatment, and increased installation costs. Therefore, it is necessary to enable practical application of simultaneous SOx and NOx treatment technologies to remove two or more contaminants in one process. The present study analyzes a technology capable of maintaining simultaneous treatment of SOx and NOx even at low temperatures due to the electrochemically generated strong oxidation of the wet-pulse complex system. This system also reduces unreacted residual gas and secondary products through the wet scrubbing process. It addresses common problems of the existing fuel gas treatment methods such as SDR, SCR, and activated carbon adsorption (i.e., low treatment efficiency, expensive maintenance cost, large installation area, and energy loss). Experiments were performed with varying variables such as pulse voltage, reaction temperature, chemicals and additives ratios, liquid/gas ratio, structure of the aeration cleaning nozzle, and gas inlet concentration. The performance of individual and complex processes using the wet-pulse discharge reaction were analyzed and compared.

• 정보관리학회지
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• 제6권1호
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• pp.3-14
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• 1989

본 연구는 학술 잡지의 발달 과정과 그 특징, 연구 논문 편수의 증가와 학회의 발달 과를 고찰하므로서 우리나라 학자들의 논문 발표의 주된 수단이 무엇인지, 학술 정보의 생 산과 축적 수단으로서 학술 잡지의 기능을 밝히고 도서관 정보 봉사를 설계하거나 개선함에 있어 올바른 방향 설정에 도움이 될 객관적 근거를 마련하는데 그 목적이 있다.