• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6159-6166
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• 2012

A discharge measurement is difficult in flood season which is especially important in the water resources field and the continuous discharge measurement for all rivers is impossible on the present system. So, the stage-discharge curve has been used for a long time to produce discharge data of rivers. However, there has been problems from a reliability angle due to the fact that this method uses only stage-discharge relationship, although the stage-discharge curve has the convenience. Therefore, a new mean velocity equation was derived by using Chiu's 2D velocity formula of the entropy concept in this paper. The derived equation reflected hydraulic characteristics such as the depth, gravity acceleration, hydraulic radius, energy slope, kinematic coefficient of viscosity, etc. and estimated also a maximum velocity. In addition, this method verified the relationship between a mean and maximum velocity and estimates an equilibrium state ${\phi}(M)$ well presenting properties of a river cross section as the results. The mean velocity was estimated by using the equilibrium state ${\phi}(M)$, and then the discharge was estimated. To prove this equation to be accurate, the comparison between the measured and estimated discharge is conducted by using the measured laboratory data in the unsteady condition flow showing loop state and the results are consistent. If this study is constantly carried out by using various laboratory and river data, this method will be widely utilized in water resources field.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.5
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• pp.1141-1154
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• 1996

The para-unitary (PU) M band filter bank, which can beused for M band decomposition, has many useful properties. In this ppaer, attempts have been made to design and and analyze the linear phase para-unitary (LPPU) M band filter bank, which is appropriate to the image coding application. First, we derive a unified coding gain in terms of the correlation in the band, as well as the energy compaction. And M band filter bank has been designed, maximizing the new coding gain. Then, we analyze the image coding performance of the LPPU M band filter bank, such as the energy compaction, the correlation in the band and the entropy. From the analysis, it is shown that the coding gain for LPPU M band filter bank improves, and the coding gain for the LPPU 4 band filter bank approaches very closely to that for LPPU 8 band filter bank, as the length of the filter increases. This fact is also verified by the coding results on the real images.

• Polymer(Korea)
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• v.33 no.1
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• pp.58-66
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• 2009

The thermotropic liquid crystalline behavior of the homologous series of cellulose tri[4-{4'-(nitrophenylazo) phenoxycarbonyl}] alkanoates (NACEn, n=2$\sim$8, 10, the number of methylene units in the spacer) have been investigated. All of the homologoues formed monotropic nematic phases. The isotropic-nematic transition temperature ($T_{iN}$) decreased when n is increased up to 7, but it became almost constant when n is more than 7. The plot of transition entropy at $T_{iN}$ against n had a sharp negative inflection at n=7. The sharp change at n=7 may be attributed to the difference in arrangement of the side groups. The melting temperature ($T_m$) and associated entropy change at $T_m$, in contrast with $T_{iN}$ and associated entropy change at $T_{iN}$, exhibited a distinct odd-even effect, suggesting that the average shape of the side chains in the crystalline phase is different from that in the nematic phase. The thermal stability and degree of order of the nematic phase observed for NACEn were significantly different from those reported for the homologous series of side-chain and combined type liquid crystal polymers bearing azobenzene or biphenyl units in the side chains. The results were discussed in terms of the differences in the chemical structure, the flexibility of the main chain, the mode of chemical linkage of the side group with the main chain, and the number of the mesogenic units per repeating unit.

• Journal of the Korean Chemical Society
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• v.35 no.5
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• pp.512-519
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• 1991

The axial ligations of nitrogenous bases (pyridine, imidazole, 1-methylimidazole and 2,6-lutidine) to Zn(II)-, Cu(II)-, and Ni(II)-tetrakis(o-chlorophenyl)porphyrin(o-ClTPP), and -tetraphenylporphyrin (TPP) were investigated in organic solvents $(CH_2Cl_2,\;C_6H_6,\;CH_3NO_2,\;(CH_3)_2CO,\;CHCl_3,\;DMF\;and\;DMSO)$ and at 0.01M of ionic strength. The equilibrium constants for the ligation reactions of methalloporphyrins were determined using spectrophotometric method at 15∼35${\circ}C$. In case of M(II)-TPP the equilibrium constants K were considerably larger than those of M(II)-(o-Cl)TPP, depending on steric effect of the porphyrin. The linear relationships between logK of the axial ligation and $pK_a$ of nitrogenous base were shown in M(II)-TPP, but not in M(II)-(o-Cl)TPP. The stabilities of MTPP(L) were controlled by the reation enthalpy and entropy, while those of M(o-Cl)TPP almost by the reaction entropy. The coordinating power of solvent to the methalloporphyrin were also studied in $CHCl_3,\;(CH_3)_2CO$, DMF and DMSO. From those results the solvent effects on the equilibrium constants were discussed.

• Journal of the Korean Chemical Society
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• v.17 no.2
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• pp.73-79
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• 1973

The ultrasonic absorption of Dodecyl pyridinium bromide (D.P.B.) in aqueous solution has been measured at $20^{\circ}C$ over a range of frequencies between 0.1 mc and 90 mc and a range of concentrations from 5 to 100 mM. The excess absorption was observed only in the solutions the concentration of which was higher than the critical micellar concentration (c.m.c.) both in the presence and absence of salt. The excess absorption of sound and the relaxation frequencies obtained from the absorption curves show a discontinuity with the variation of the concentration of D.P.B. in the neighborhood of 60 mM. Other properties such as viscosity, conductivity and velocity of sound also exhibit such a change near the same concentration. It is concluded that a change in the properties of the micelles of D.P.B. occurs in the neighborhood of this concentration. The mechanism of the observed ultrasonic excess absorption in attributed to the reaction $M_2{\rightleftarrow}M_1+2Br^-$where$M_2$ and$M_1$are two types of micelles. The rate constants of forward and backward reactions are found to be $6.9 {\times} 10^5 sec^{-1)$and $6.7{\times}10^{10}sec^{-1}mole{-2}$ respectively. Some kinetic characteristics including free energy, enthalpy, entropy and activation energy were calculated.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.2
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• pp.103-113
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• 2001

This paper described a design and implementation of a single-chip encoder/decoder using the LZSS algorithm and entropy coding in 0.6${\mu}{\textrm}{m}$ CMOS technology. Dictionary storage for the dictionary search processor(DISP) used a 2K$\times$8bit on-chip memory with 50MHz clock speed. It performs compression on byte-oriented input data at a data rate of one byte per clock cycle except when one out of every 33 cycles is used to update the string window of dictionary. In result, the average compression ratio is 46% by applied entropy coding of the LZSS codeword output. This is to improved on the compression performance of 7% much more then LZSS.

• Journal of the Korean Chemical Society
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• v.23 no.4
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• pp.187-197
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• 1979

The molar optical rotation of poly(cis-5-methylproline) was measured in solvent mixtures of chloroform and chloroethanol. After proper allowance for time-dependent mutarota-tions, equilibrium states between form A and form B were observed to occur with a solvent composition of 0.5~10 % chloroethanol in chloroform by volume. From the equilibrium constants, which were calculated by optical rotations at equilibrium measured at three different temperatures (5, 25, and 45 $^{circ}$C), the thermodynamic parameters-free enthalpy, enthalpy and entropy changes for the mutarotation-were evaluated. It was found that starting with equimolar concentrations of form A and form B, the forward mutarotation occurred in the solvent compositions of chloroethanol greater than 3 % by volume, whereas the reverse mutarotation resulted in solvent compositions of chloroethanol less than 3 % by volume. The changes in enthalpy and entropy for the forward mutarotation were found to be positive, while those were for the reverse mutarotation were negative. The driving forces for the forward mutarotation were found to be the increase in entropy, whereas that for the reverse mutarotation was the negative enthalpy change. The thermodynamic data were explained by the interaction between polymer and solvent, i.e., preferential hydrogen bonding of chloroethanol with the carbonyl group in form B over form A, and by difference in conformational energies between form A and form B.

• Journal of Environmental Science International
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• v.26 no.9
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• pp.999-1011
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• 2017

In this study, the Chiu-2D velocity-flow rate distribution based on theoretical background of the entropy probability method was applied to actual ADCP measurement data of Gangjung Stream in Jeju from July 2011 to June 2015 to predict the parameter that take part in velocity distribution of the stream. In addition, surface velocity measured by SIV (Surface Image Velocimeter) was applied to the predicted parameter to calculate discharge. Calculated discharge was compared with observed discharge of ADCP observed during the same time to analyze propriety and applicability of depth of water velocity average conversion factor. To check applicability of the predicted stream parameter, surface velocity and discharge were calculated using SIV and compared with velocity and flow based on ADCP. Discharge calculated by applying velocity factor of SIV to the Chiu-2D velocity-flow rate distribution and discharge based on depth of water velocity average conversion factor of 0.85 were $0.7171m^3/sec$ and $0.5758m^3/sec$, respectively. Their error rates compared to average ADCP discharge of $0.6664m^3/sec$ were respectively 7.63% and 13.64%. Discharge based on the Chiu-2D velocity-flow distribution showed lower error rate compared to discharge based on depth of water velocity average conversion factor of 0.85.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2523-2528
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• 2014

In the present study, at first, azo Schiff base ligand of (N,N'-bis(5-phenylazosalicylaldehyde)-ethylenediamine) ($H_2L$) has been synthesized by condensation reaction of 5-phenylazosalicylaldehyde and ethylenediamine in 2:1 molar ratio, respectively. Then, its cobalt complex (CoL) was synthesized by reaction of $Co(OAc)_2{\cdot}4H_2O$ with ligand ($H_2L$) in 1:1 molar ratio in ethanol solvent. This ligand and its cobalt complex containing azo functional groups were characterized using elemental analysis, $^1H$-NMR, UV-vis and IR spectroscopies. Subsequently, the interaction between native calf thymus deoxyribonucleic acid (ct-DNA) and CoL complex was investigated in 10 mM Tris/HCl buffer solution, pH = 7 using UV-vis absorption, thermal denaturation technique and viscosity measurements. From spectrophotometric titration experiments, the binding constant of CoL complex with ct-DNA was found to be $(2.4{\pm}0.2){\times}10^4M^{-1}$. The thermodynamic parameters were calculated by van't Hoff equation.The enthalpy and entropy changes were $5753.94{\pm}172.66kcal/mol$ and $43.93{\pm}1.18cal/mol{\cdot}K$ at $25^{\circ}C$, respectively. Thermal denaturation experiments represent the increasing of melting temperature of ct-DNA (about $0.93^{\circ}C$) due to binding of CoL complex. The results indicate that the process is entropy-driven and suggest that hydrophobic interactions are the main driving force for the complex formation.

• Journal of Magnetics
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• v.18 no.2
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• pp.150-154
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• 2013

$La_{1-z}Nd_z(Fe_{0.88}Si_{0.12})_{13}$ and their hydrides were investigated to obtain large magnetocaloric effects (MCEs) in a wide temperature range, including room temperature, for applications in magnetic refrigents. Since the magnetization change due to the itinerant-electron metamagentic (IEM) transition for $La_{1-z}Nd_z(Fe_{0.88}Si_{0.12})_{13}$ becomes larger with increasing z, the isothermal magnetic entropy change ${\Delta}S_m$ and the relative cooling power (RCP) are enhanced. In addition, the Curie temperatrue $T_C$ of $La_{0.8}Nd_{0.2}(Fe_{0.88}Si_{0.12})_{13}$ is increased from 193 to 319 K by hydrogen absorption, with the IEM transition. The maximum value of $-{\Delta}S_m$, $-{\Delta}S{_m}^{max}$, in a magnetic field change of 2 T for $La_{0.8}Nd_{0.2}(Fe_{0.88}Si_{0.12})_{13}H_{1.1}$ is about 23 J/kg K at $T_C$ = 288 K, which is larger than that of 19 J/kg K at $T_C$ = 276 K for $La(Fe_{0.88}Si_{0.12})_{13}H_{1.0}$. The value of RCP = 179 J/kg of the former is also larger than 160 J/kg of the latter. It is concluded that the partial substitution of Nd improves MCEs in a wide temperautre range, including room temperature.