• Bulletin of the Korean Mathematical Society
• /
• v.44 no.4
• /
• pp.789-794
• /
• 2007

Let R be a 3-torsion free semiprime ring and let I be a nonzero two-sided ideal of R. Suppose that there exists a permuting 3-derivation ${\Delta}:R{\times}R{\times}R{\rightarrow}R$ such that the trace is centralizing on I. Then the trace of ${\Delta}$ is commuting on I. In particular, if R is a 3!-torsion free prime ring and ${\Delta}$ is nonzero under the same condition, then R is commutative.

• Journal of the Korean Chemical Society
• /
• v.53 no.2
• /
• pp.118-124
• /
• 2009

The values of critical micelle concentration (CMC) and counter ion binding constants (B) in a micellar state of CPC (1-hexadecylpyridinium chloride) with Brij 35 (polyoxyethylene(23) lauryl ether) in water were determined as a function of ${\alpha}_1$ (the overall mole fraction of CPC) by the use of electric conductivity method. Various thermodynamic parameters ($X_i,\;{\gamma}_i,\;C_i,\;a_{i}^{M},\;\beta,\;and\;{\Delta}H_{mix}$) were calculated and analyzed by means of the equations derived from the non-ideal mixed micellar model. And thermodynamic parameters (${\Delta}{G^o}_m,\;{\Delta}{H^o}_m,\;and\;{\Delta}{S^o}_m$) for the micellization of CPC/Brij 35 mixtures were also calculated from the temperature dependence of the CMC values. The values of ${\Delta}{G^o}_m$ are all negative, but the values of ${\Delta}{S^o}_m$ and ${\Delta}{H^o}_m$ are positive or negative, depending on the measured temperature and ${\alpha}_1$.

• Communications of the Korean Mathematical Society
• /
• v.30 no.3
• /
• pp.143-154
• /
• 2015

Characterizations of hesitant fuzzy left (right) ideals are considered. The notion of hesitant fuzzy (generalized) bi-ideals is introduced, and related properties are investigated. Relations between hesitant fuzzy generalized bi-ideals and hesitant fuzzy semigroups are discussed, and characterizations of (hesitant fuzzy) generalized bi-ideals and hesitant fuzzy bi-ideals are considered. Given a hesitant fuzzy set $\mathcal{H}$ on a semigroup S, hesitant fuzzy (generalized) bi-ideals generated by $\mathcal{H}$ are established.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.29 no.6
• /
• pp.457-463
• /
• 2018

This paper compares the results of ${\Sigma}{\Delta}-STAP$ applied to actual radar test data and simulation data. The radar received a target signal from a virtual target generator and the clutter signal from a signal generator in an anechoic chamber. The simulation data were generated from ideal baseband radar signal modeling using the same parameter as that for the test radar. The ${\Sigma}{\Delta}-STAP$ results of the test and simulation data are similar in terms of the target signal shape and noise level. The SINR(Signal-to-Interfrence-plus-Noise Ratio) loss also had similar aspects, but the simulation result shows 1~2 dB higher SINR loss than the test result. This result verified that the simulation data can be a reasonable alternative test data when the ${\Sigma}{\Delta}-STAP$ is applied.

• Korean Journal of Chemical Engineering
• /
• v.35 no.11
• /
• pp.2269-2282
• /
• 2018

Mixed micelle formation behavior of cationic surfactant-cetyltrimethylammonium bromide (CTAB) and anionic surfactant sodium dodecyl sulfate (SDS) in aqueous as well as in urea medium from 303.15 K to 323.15 K at 5 K interval was carried out by conductometric method. The differences between the experimental values of critical micelle concentrations (cmc) and ideal critical micelle concentrations ($cmc^{id}$) illustrate the interaction between the amphiphiles studied. The values of micellar mole fraction ($X_1^{Rub}$ (Rubingh), $X_1^M$ (Motomura), $X_1^{Rod}$ (Rodenas) and $X_1^{id}$(ideal) of surfactant CTAB determined by different proposed models and outcome indicate high involvement of CTAB in SDS-CTAB mixed micellization, which enhance by means of the augment of mole fraction of CTAB. The negative value of interaction parameter (${\beta}$) showed an attractive interaction involving CTAB and SDS. Activity coefficients were less than unity in all case, which also reveals the presence of interaction between CTAB & SDS. The negative ${\Delta}G^0_m$ values imply the spontaneous mixed micellization phenomenon. The attained values of ${\Delta}H^0_m$ were positive at inferior temperature, while negative at superior temperature. The negative ${\Delta}H^0_m$ values in urea ($NH_2CONH_2$) medium illustrate exothermic micellization process. The magnitudes of ${\Delta}S^0_m$ were positive in almost all cases. The excess free energy of mixed micelle formation (${\Delta}G_{ex}$) was found to be negative, which indicates the stability of mixed micelle as compared to the individual's components micelles.

• Communications of the Korean Mathematical Society
• /
• v.14 no.1
• /
• pp.39-45
• /
• 1999

In this paper, we improve some of results in [2] by showing that if I is a cnacellation ideal and if J is a regular ideal then $\alpha$(m), $\beta$(m) and $\delta$(m), behave nicely under localization. We prove that lim \ulcorner=0 if and only if $\alpha$(m) is eventually constant and that lim\ulcorner exists and is equal to or less than $\alpha$(1). Finally we give several conditions which are equivalent to $lim_{m{\rightarrow}{\infty}}{\frac{{\alpha}(m)}{m}}=0$.

• Communications of the Korean Mathematical Society
• /
• v.33 no.4
• /
• pp.1113-1121
• /
• 2018

Let R be a prime ring (or semiprime ring) with center Z(R), I a nonzero ideal of R, T an automorphism of $R,S:R^n{\rightarrow}R$ be a symmetric skew n-derivation associated with the automorphism T and ${\Delta}$ is the trace of S. In this paper, we shall prove that S($x_1,{\ldots},x_n$) = 0 for all $x_1,{\ldots},x_n{\in}R$ if any one of the following holds: i) ${\Delta}(x)=0$, ii) [${\Delta}(x),T(x)]=0$ for all $x{\in}I$. Moreover, we prove that if $[{\Delta}(x),T(x)]{\in}Z(R)$ for all $x{\in}I$, then R is a commutative ring.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.3
• /
• pp.889-893
• /
• 2011

The energetics and transition state (TS) structures of the reactions of six substrates, $R_1R_2P$(=O or S)Cl-type where $R_1=R_2$=Me and/or MeO, with ammonia in acetonitrile are theoretically investigated at the level of CPCM-MP2/6-31+G(d) and CPCM-MP2/6-311+G(3df,2p). The degrees of distortion of TS from the ideal trigonal bipyramidal pentacoordinate, ${\Delta}{{\delta}}_{{\neq}b}$ for a backside and ${\Delta}{{\delta}}_{{\neq}f}$ for a frontside attack, are calculated. The results of calculation suggest that the feasibility of a frontside attack for P=S is greater than that for P=O system when the two ligands, $R_1$ and $R_2$, becomes larger. The experimental and calculated results of anilinolyses of $R_1R_2P$(=O or S)Cl-type show the consistent tendencies.

• Economic and Environmental Geology
• /
• v.25 no.3
• /
• pp.275-282
• /
• 1992

Mineral chemistry and stable isotope compositions of sericites from the Sangdong mine in the Kimhae area, Kyungsangnamdo, were studied. The Sangdong sericite deposit occurs in rhyolitic tuff of late Cretaceous age and considers to have been fonned by the hydrothennal alteration. The sericites are classified as $2M_1$ polytype and are characterized by less celadonite substitution indicating muscovite-phengite series. Their compositions are very close to that of the ideal muscovite but net layer charge ranges 1.71~1.91 which is less than 2 per formula unit of ideal muscovite. Predominant interlayer cation is K and K/(K+Na) ratio ranges 0.91 and 0.93. ${\delta}^{18}O$ values of sericites and quartz separated from the ore range 7.70~9.07 and 8.20~10.87‰, respectively. The formation temperature of sericite can be estimated as $315{\sim}340^{\circ}C$( based on ${\delta}^{18}O$ value of sericite and ${\delta}D$ value of of Cretaceous meteoric water. Their formation temperature discrepancy between coexisting sericite and quartz indicates that they are in isotopically inequilibrium. Two types of quartz, coarse grained phenocrysts and micrcrystalline aggregates are observed and the former must have been formed during volcanic eruption and remained isotopically unexchanged during hydrothermal alteration period. ${\delta}^{14}S$ values of pyrites range 1.9~4.5‰ which is within a range of volcanogenic sulfur, indicating magmatic source.

• Journal of Power Electronics
• /
• v.12 no.6
• /
• pp.974-981
• /
• 2012

A FPGA based delta modulated single phase matrix converter has been developed that may be used in both cyclo-converters and cyclo-inverters. This converter is ideal for variable speed electrical drives, induction heating, fluorescent lighting, ballasts and high frequency power supplies. The peripheral input-output and FPGA interfacing have been developed through Xilinx 9.2i, to generate delta modulated trigger pulses for the converter. The controller has been relieved of the time consuming computational task of PWM signal generation by implementing the method of trigger pulse generation in a FPGA by using Hardware Description Language VHDL in Xilinx. The trigger circuit has been tested qualitatively by observing various waveforms on an oscilloscope. The operation of the proposed system has been found to be satisfactory.