• Title/Summary/Keyword: C2 Theory

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Ab initio Studies on d8-MCI(PH3)2(C2H2), M=Rh and Ir, Complexes

  • Kang, Sung-Kwon;Song, Jin-Soo;Moon, Jung-Hyun;Yun, Sock-Sung
    • Bulletin of the Korean Chemical Society
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    • v.18 no.1
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    • pp.27-32
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    • 1997
  • The geometries and energies of the isomers in alkyne complexes MCl(PH3)2(η2-C2H2), M=Rh and Ir, are theoretically investigated using ab initio methods at the Hartree-Fock and up to MP4 level of theory and relativistic effective core potentials for Rh and Ir metals. The optimized structures of Rh complexes, 1-3 at MP2/ECP1 level are in good agreement with the related experimental data. The binding energies of C2H2 to d8-metal fragments are computed to be ∼55 kcal/mol. The vinylidene complexes for Rh and Ir metals are calculated to be much lower in energy than the alkyne complexes. The alkyne-vinylidene rearrangement is possible to proceed exothermically through the intermediate hydrido-alkynyl complexes, 2 or 9. Detailed comparison is given about the geometries and relative energies on Rh and Ir isomers at the various level ab initio calculations with orbital analysis.

A STUDY ON THE HYDROELASTIC RESPONSE OF A PLATE UNDER IMPULSIVE PRESSURES DUE TO BREAKING WAVES

  • Park, Hang-Shoon;Lee, Dong-Yeon
    • Journal of Theoretical and Applied Mechanics
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    • v.2 no.1
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    • pp.1-14
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    • 1996
  • In this paper, breaking waves are generated in a 2-D wave tank and simulated by using a higher-order boundary element method. A piston-type wavemaker is operated by signals composed of elementary waves. The phase of elementary waves is determined by the linear theory such that they are focused to a prescribed position. Calculated plunging waves coincide well with experiment. A steel box with different plate thicknesses is installed at a predetermined position in the tank. Measured impulsive pressures due to breaking waves are found to be 0.8-1.2$\rho$C2, where $\rho$ corresponds to water density and C to wave celerity. The transverse displacement of the plate is described in terms of modal eigenfunctions. The natural frequencies measured by impact tests in air for thin plate coincide with the computational and theoretical values. The radiationpotential due to plate vibration is derived and the radiation force is expressed in terms of hydroelastic added mass and damping forces. Comparison of natural frequencies of plate in water proves that hydroelastic added mass and damping are properly considered. The measured strain due to regular waves supports the calculated one, but there are apparent discrepancies between theory and experiment in the impulsive case.

Design of Evaluation Index System for Information Experience based on B2C e-Commerce Bigdata and Artificial Intelligence

  • KANG, Jangmook;HU, Haibo;CHEN, Yinghui;LEE, Sangwon
    • International journal of advanced smart convergence
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    • v.8 no.4
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    • pp.1-8
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    • 2019
  • The online retail market continues to grow, especially in China, as e-commerce has developed rapidly in recent years in many countries. Meanwhile, the development and use of new network information technology provides consumers with various contact and experience environments for online shopping. Based on the theory of media weakness, the study began to focus consumer experience on the nature of commercial transactions. The study proposed and designed an initial measure of the consumer information evaluation index, which combines previous findings with implications. Finally, the five-dimensional B2C system was established to evaluate consumers' information experience providing information display, information interaction, information support and information personalization. We researched on evaluation index system for information experience of B2C e-commerce consumers based on samples of Chinese consumers.

A Study on The Assesment of Power Improvement Effectiveness of Corps Level C4I System Applied to Integrated Fire Operation (지상전술 C4I체계의 통합화력운용간 전투력 상승효과 평가에 관한 연구)

  • 박송기;이재영
    • Journal of the military operations research society of Korea
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    • v.29 no.1
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    • pp.8-27
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    • 2003
  • This paper develops a methodology that can be used to quantify the assesment of power improvement effectiveness of corps level C4I system applied to integrated fire operation by adapting Schuzer's C2 theory. This paper first describes how C4I systers can enhance the battle outcome in three way. : (1) Enhanced unit probability of survival; (2) Enhanced unit's individual effectiveness; improved exchange ratios; (3) Improved task force allocations : increased percentage of assets that can be assigned to a given engagement These enhancements are then show to result from improved probability of detection through information sharing; improved survivability and lethality through battle force coordination; and enhanced force allocation and prepositioning through improved timeliness of information(more advanced warning). It demonstrates that well-designed C4I systems can be shown to represent a significant force multiplier on the outcome of the battle.

A Study on Autoignition of Fish Meal with Change of Ambient Temperature (주위온도 변화에 따른 어분의 자연발화에 관한연구)

  • 목연수;최재욱
    • Journal of the Korean Society of Safety
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    • v.7 no.1
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    • pp.47-56
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    • 1992
  • Spontaneous ignition charactenstics for fish meal were observed by performing experiments at constant ambient temperature and varying the ambient temperature sinusoidally. As the results of the experiments at a constant ambient temperature, the critical spontaneous ignition temperature of the sample for large, intermediate and small vessels was 170.5$^{\circ}C$, 177.5$^{\circ}C$ and 188.5$^{\circ}C$, respectively. The critical spontaneous ignition temperature decreased as the sample vessel size increased. Apparent activation energy of used fish meal calculated from the Frank-Kamenetskii's thermal ignition theory was 37.60Kcal/mol. In case of varying the ambient temperature sinusoidally, the amplitudes of temperature were 1$0^{\circ}C$, 2$0^{\circ}C$ and 3$0^{\circ}C$ respectively with the period in each amplitude 1hr, 2hrs and 3hrs. The results showed that the critical spontaneous ignition temperatures at the varied amplitudes of temperature were lower than that at the constant anbient temperature and increased as the amplitude increased. At the same amplitude, the critical spontaneous ignition temperature increased with the period.

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The Strength of Square Steel Tubular Column to H-beam Connections - Focused on the connections with outside-type diaphragm - (각형강관 기둥 - H형강 보의 접합부 내력 평가 - 외측형 다이아프램 접합부를 중심으로 -)

  • Lee, Seong Do;Kim, Pil Jung;Kim, Kyu Suk
    • Journal of Korean Society of Steel Construction
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    • v.16 no.1 s.68
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    • pp.11-20
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    • 2004
  • This paper focused on square steel tubular column to H-beam connections (concrete filled tubular) with an outside-type diaphragm. Based on the yield line theory and the nonlinear static FEM analysis the specification equations were evaluated by comparing them with previous result of the simplified tensile experiment[please check. The yield line theory applied to the mechanical model theory revised by K. Morita, the nonlinear static FEM analysis using abaqus/standard, the ultimate strength equation in the specification equation using the factor for long-time loading, and the yield ratio according to material. The allowable strength in the specification equations applied the safety factors of 2.2 and 2.6 in the cases with and without filled concrete, respectively. Therefore, the evaluation of strength(for the previous result of the simplified tensile experiment in this study) was considered possible through the yield line theory, the nonlinear static FEM analysis, and the specification equations. Likewise, the specification equations were seen to be an underestimate of the previous result of the simplified tensile experiment. The strength and displaced mesh in the FEM analysis approximated the previous result of the simplified tensile experiment.

Methodologies for numerical modelling of prestressed concrete box-girder for long term deflection

  • Lalanthi, M.C.;Kamatchi, P.;Balaji Rao, K.;Saibabu, S.
    • Computers and Concrete
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    • v.21 no.3
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    • pp.269-278
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    • 2018
  • In this paper, two methods M1 and M2 to determine long-term deflection through finite element analyses including the effect of creep and relaxation are proposed and demonstrated for a PSC box-girder. In both the methods, the effect of creep is accounted by different models from international standards viz., ACI-209R-92, CEB MC 90-99, B3 and GL2000. In M1, prestress losses due to creep and relaxation and age adjusted effective modulus are estimated through different models and have been used in finite element (FE) analyses for individual time steps. In M2, effects of creep and relaxation are implemented through the features of FE program and the time dependent analyses are carried out in single step. Variations in time-dependent strains, prestress losses, stresses and deflections of the PSC box-girder bridge through M1 and M2 are studied. For the PSC girder camber obtained from both M1 and M2 are lesser than simple bending theory based calculations, this shows that the camber is overestimated by simple bending theory which may lead to non-conservative design. It is also observed that stresses obtained from FEM for bottom fibre are lesser than the stresses obtained from bending theory at transfer for the PSC girder which may lead to non-conservative estimates.

Theoretical Study on the Reaction Mechanism of Azacyclopropenylidene with Epoxypropane: An Insertion Process

  • Tan, Xiaojun;Wang, Weihua;Li, Ping
    • Bulletin of the Korean Chemical Society
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    • v.35 no.9
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    • pp.2717-2722
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    • 2014
  • The reaction mechanism between azacyclopropenylidene and epoxypropane has been systematically investigated employing the second-order M${\o}$ller-Plesset perturbation theory (MP2) method to better understand the reactivity of azacyclopropenylidene with four-membered ring compound epoxypropane. Geometry optimization, vibrational analysis, and energy property for the involved stationary points on the potential energy surface have been calculated. It was found that for the first step of this reaction, azacyclopropenylidene can insert into epoxypropane at its C-O or C-C bond to form spiro intermediate IM. It is easier for the azacyclopropenylidene to insert into the C-O bond than the C-C bond. Through the ring-opened step at the C-C bond of azacyclopropenylidene fragment, IM can transfer to product P1, which is named as pathway (1). On the other hand, through the H-transferred step and subsequent ring-opened step at the C-N bond of azacyclopropenylidene fragment, IM can convert to product P2, which is named as pathway (2). From the thermodynamics viewpoint, the P2 characterized by an allene is the dominating product. From the kinetic viewpoint, the pathway (1) of formation to P1 is primary.

On the browder-hartman-stampacchia variational inequality

  • Chang, S.S.;Ha, K.S.;Cho, Y.J.;Zhang, C.J.
    • Journal of the Korean Mathematical Society
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    • v.32 no.3
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    • pp.493-507
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    • 1995
  • The Hartman-Stampacchia variational inequality was first suggested and studied by Hartman and Stampacchia [8] in finite dimensional spaces during the time establishing the base of variational inequality theory in 1960s [4]. Then it was generalized by Lions et al. [6], [9], [10], Browder [3] and others to the case of infinite dimensional inequality [3], [9], [10], and the results concerning this variational inequality have been applied to many important problems, i.e., mechanics, control theory, game theory, differential equations, optimizations, mathematical economics [1], [2], [6], [9], [10]. Recently, the Browder-Hartman-Stampaccnia variational inequality was extended to the case of set-valued monotone mappings in reflexive Banach sapces by Shih-Tan [11] and Chang [5], and under different conditions, they proved some existence theorems of solutions of this variational inequality.

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A Study on the Expression in Modern Fashion-Focusing on the Aesthetics Theory of Verfremdung-

  • Eom, So-Hee;Kim, Moon-Sook
    • The International Journal of Costume Culture
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    • v.3 no.1
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    • pp.21-29
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    • 2000
  • The purpose of this study was to analyze the 21C Fashion's expression related to 'Verfremdung' theory, in aesthetic theories established after modern times, and then to examine a new meaning and value. The expressions of 'Verfremdung(estrangement)' in modern fashion, appear the followings: 1) placing distance with traditional sex and rational beauty of body. 2) paradox of inversion, 3) illogical juxtapositions by encounter. 4) dismantlement of material concept etc. After showing practically production technique that breaks traditional exception, that is, a new design method of open concept which drives positive idea about discrepancy of realities. This trial has warning abut art's self-control occurring at the time when aesthetic disinterestedness theory is expanded, and is considered indictment about a inhuman property of modern civilization and culture, and is considered expression of will to show alienation by it.

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