• Textile Coloration and Finishing
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• v.24 no.3
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• pp.158-164
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• 2012

Rhodamine dyes belong to xanthene family has excellent photostability and photophysical properties. In rhodamine dyes, Rhodamine 6G and its precursors also have xanthene chromophore and it shows high fluorescent quantum yield. Rhodamine 6G derivates are simple to synthesis and its high sensitivity and water solubility are suitable as good chemosensor. In this regard, Rhodamine 6G derivates which have selectivity to specific metal cation can used to detect various heavy metal ions. In this study, rhodamine 6G derivatives were synthesized by reaction of rhodamine 6G hydrazide and glyoxal and 4-phenyl thiosemicarbazide and it showed colorimetric and fluorescence sensing toward $Hg^{2+}$ ion. This novel chemosensor was analyzed and measured on UV-Vis and fluorescence spectrophotometer. HOMO/LUMO values were also calculated by computational calculation.

• Journal of The Korean Astronomical Society
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• v.8 no.1
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• pp.29-34
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• 1975

Solar electrical conductivity has been calculated, making use of Yun and Wyller's formulation. The computed results arc presented in a tabulated form as functions of temperature and pressure for given magnetic field strengths. The results of the calculation show that the magnetic field does not play any important role in characterizing the electrical conductivity of the ionized gas when the gas pressure is relatively high (e.g., $P{\geq}10^4\;dynes/cm^2$). However, when the gas pressure is low (e.g., $P{\leq}10\;dynes/cm^2$), the magnetic field becomes very effective even if its field strength is quite small (e.g., $B{\leq}0.01$ gauss). It is also found that, except for lower temperature region (e.g., $T{\leq}10^{4^{\circ}}K$), there is a certain linear relationship in a log- log graph between the pressure and the critical magnetic field strength, which is defined as a field strength capable of reducing the non-magnetic component of the electrical conductivity by 20%.

• The Journal of the Korea Contents Association
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• v.7 no.10
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• pp.10-18
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• 2007

Today, third-generation(3G) of mobile communication service executing the video and TV. And low cost, high speed data rate will emerge communication of the fourth generation(4G) in future. So, in this paper we studied occupied frequency bandwidth of common technique criteria among the technique criteria for the 4G mobile communication of FDD-based on Up/Down-link. The mobile communication traffic is predicted Up/Down-link of non-symmetric in future. So we proposed the PHY layer parameters of occupied frequency bandwidth of Up/Down-link with both 1:3 and 1:6. We also verified this through the simulation. We proposed the occupied frequency bandwidth for the 4G mobile communication in this paper.

• Transactions of Materials Processing
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• v.25 no.4
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• pp.248-253
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• 2016

Induction hardening process of tubular drive shaft for automobile is simulated by combining the thermal, mechanical, electro-magnetic and metallurgical analysis models. Various material properties for each analysis model are obtained in a consistent way via material properties calculation software, JMatPro^®. To consider the scanning process of induction heating, boundary element method is adopted for electro-magnetic field calculation. The distribution of temperature, stress and phase volume fraction are tracked out through the whole process and the effect of scanning velocity is reviewed. The analysis result shows that the critical principal stress is developed at the phase boundary where martensite is formed.

• Bulletin of the Society of Naval Architects of Korea
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• v.21 no.4
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• pp.40-48
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• 1984

The computer program DASH(Direct Analysis of Ship's Hull), based on the direct calculating procedure as proposed at the 4th ISSC(1970), was developed. The DASH program is designed by the following calculation procedure: 1) Derivation of the design wave loads through the ship motion analysis based on the strip theory. 2) Stress analysis of the hull girder based on the 7-degree of the freedom beam theory including the warping torsion effect. 3) Long-term prediction of the stresses based on the statistical approach using sea-spectrums and ocean wave data in the ship's route. An example calculation was performed for the purpose of a demonstration of the present approach on the 16,200 DWT Oil Tanker. The results are discussed and compared with the conventional method.

• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.4098-4102
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• 2012

The potential energy surface (PES) for the loss of HCN from the pyrimidine molecular ion has been explored using quantum chemical calculations. Possible reaction pathways to form five $C_3H_3N^{+{\bullet}}$ isomers have been obtained with Gaussian 4 model calculations. The rate constant for the HCN loss and the product branching ratio have been calculated using the Rice-Ramsperger-Kassel-Marcus theory on the basis of the obtained PES. The resultant rate constant agrees with the previous experimental result. By a kinetic analysis, it is proposed that the formation of $CH=CHC{\equiv}NH^{+{\bullet}}$ is favored near the dissociation threshold, while the formation of $CH=CHN{\equiv}CH^{+{\bullet}}$ is favored at high energies.

• Bulletin of the Korean Chemical Society
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• v.30 no.4
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• pp.794-796
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• 2009

We have studied the structures and stabilities of Au6 to explore the origin of the large discrepancy between relative energies obtained from the density functional theory (DFT) and ab initio correlated levels of theory. The MP2 methods significantly overestimate the stability of the non-planar isomer when the double-$\zeta$ polarization quality of basis sets, such as LANL2DZ+1f and CEP31G+1f, are used. However, we show that such preference for the non-planar structure at the MP2 level mainly originates from the large basis set superposition error.

• Transactions of Materials Processing
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• v.30 no.4
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• pp.186-194
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• 2021

Finite element simulation is a widely applied method for practical purpose in various metal forming process. However, in the simulation of elasto-plastic behavior of porous material or in crystal plasticity coupled multi-scale simulation, it requires much calculation time, which is a limitation in its application in practical situations. A machine learning model that directly outputs the constitutive equation without iterative calculations would greatly reduce the calculation time of the simulation. In this study, we examined the possibility of artificial intelligence based constitutive equation with the input of existing state variables and current velocity filed. To introduce the methodology, we described the process of obtaining the training data, machine learning process and the coupling of machine learning model with commercial software DEFROM^TM, as a preliminary study, via rigid plastic finite element simulation.

• Journal of Advanced Marine Engineering and Technology
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• v.5 no.1
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• pp.28-33
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• 1981

The characteristics of typical 35 kinds of domestic anthracites among 155 kinds are studied to find the calculation formula for the required quantity of air and the combustion gas quantity. 1) The author's calculation formulae are as follows: ${A_0}={\frac{1, 000}{1, 064}}{H_1}+0.086(Nm^3/kg)$ ${G_0}={\frac{1, 000}{1, 110}}{H_1}+0.234(Nm^3/kg)$(1) Theoretically required quantity of air (2) Theoretical quantity of combustion gas 2) Theoretical quantity of air in combustion of domestic anthracite is always estimated more with Rosin's formula than author's one in the typical domestic anthracites which have the lower calorific value between 3, 000-8, 000 Kcal/kg and the difference of the calculated quantity of air becomes small, as the calorific value increases. 3) Theoretical quantity of combustion gas is estimated more by author's formula than by Rosin's one with the domestic anthracites which have more calorific value than 6, 700 Kcal/kg and is estimated less in the under range of the above calorific value. 4) Theoretical quantity of required air and quantity of combustion gas of domestic anthracite show ${\pm}$4% difference by Rosin's formulae in comparison with results of actual analysis, and about ${\pm}$1.5% by the author's one.

• Journal of the Korean Chemical Society
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• v.53 no.5
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• pp.521-529
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• 2009

Molecular structures of the various conformers for the 1,3-dimethoxy-p-tert-butylthiacalix[4] crown-5-ether (3) were optimized by using DFT B3LYP/6 - 31 + G(d,p) and mPW1PW91/6 - 31 + G(d,p) (hybrid HF-DF) calculation methods. We have analyzed the energy differences and structures of eight in/out orientations (cone_oo, cone_oi, pc_oo, pc_io, pc_oi, pc_ii, 13a_oo, 13a_io) of two methoxy groups in three major conformations (cone, partial-cone and 1,3-alternate). The 13a_oo (out-out orientation of the 1,3-alternate conformer) is calculated to be the most stable among eight different conformations of 3, and in accord with the experimental result. The ordering of relative stability resulted from the mPW1PW91/6 - 31 + G(d,p) calculation method is following: 13a_oo > 13a_io$\sim$pc_io$\sim$cone_oo > cone_oi$\sim$pc_oo$\sim$pc_oi > pc_ii.