• Communications of the Korean Mathematical Society
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• v.26 no.3
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• pp.373-384
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• 2011

In this paper we introduce and give some characterizations of (m, n)-regular le-${\Gamma}$-semigroup in terms of (m, n)-ideal elements and (m, n)-quasi-ideal elements. Also, we give some characterizations of subidempotent (m, n)-ideal elements in terms of $r_{\alpha}$- and $l_{\alpha}$- closed elements.

• Communications of the Korean Mathematical Society
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• v.33 no.1
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• pp.1-12
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• 2018

We introduce the notion of ordered intra k-regular semirings, characterize them using their ordered k-ideals and prove that an ordered semiring S is both ordered k-regular and ordered intra k-regular if and only if every ordered quasi k-ideal or every ordered k-bi-ideal of S is ordered k-idempotent.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04b
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• pp.17-17
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• 2009

We report the invention of a direct growth method termed On-Film Formation of Nanowire (OFF-ON) for making high-quality single-crystal nanowires, i.e. Bi and $Bi_2Te_3$, without the use of conventional templates, catalysts, or starting materials. We have used the OFF-ON technique to grow single crystal semi-metallic Bi and compound semiconductor $Bi_2Te_3$ nanowires from sputtered Bi and BiTe films after thermal annealing, respectively. The mechanism for nanowire growth is stress-induced mass flow along grain boundaries in the polycrystalline films. OFF-ON is a simple but powerful method for growing perfect single-crystal semi-metallic and compound semiconductor nanowires of high aspect ratio with high crystallinity that distinguishes it from other competitive growth approaches that have been developed to date. Our results suggest that Bi and $Bi_2Te_3$ nanowires grown by OFF-ON can be an ideal material system for exploring their unique thermoelectric properties due to their high-quality single crystalline and high conductivity, which have consequence and relevance for high-efficiency thermoelectric devices.

• Honam Mathematical Journal
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• v.36 no.3
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• pp.569-596
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• 2014

In several applied disciplines like control engineering, computer sciences, error-correcting codes and fuzzy automata theory, the use of fuzzied algebraic structures especially ordered semi-groups and their fuzzy subsystems play a remarkable role. In this paper, we introduce the notion of (${\in},{\in}{\vee}\bar{q}_k$)-fuzzy subsystems of ordered semigroups namely (${\in},{\in}{\vee}\bar{q}_k$)-fuzzy generalized bi-ideals of ordered semigroups. The important milestone of the present paper is to link ordinary generalized bi-ideals and (${\in},{\in}{\vee}\bar{q}_k$)-fuzzy generalized bi-ideals. Moreover, different classes of ordered semi-groups such as regular and left weakly regular ordered semigroups are characterized by the properties of this new notion. Finally, the upper part of a (${\in},{\in}{\vee}\bar{q}_k$)-fuzzy generalized bi-ideal is defined and some characterizations are discussed.

• Honam Mathematical Journal
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• v.39 no.4
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• pp.527-559
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• 2017

The main motivation of this article is to generalized the concept of fuzzy ideals, (${\alpha},{\beta}$)-fuzzy ideals, (${\in},{\in}{\vee}q_k$)-fuzzy ideals of semigroups. By using the concept of $q^{\delta}_K$-quasi-coincident of a fuzzy point with a fuzzy set, we introduce the notions of (${\in},{\in}{\vee}q^{\delta}_k$)-fuzzy left ideal, (${\in},{\in}{\vee}q^{\delta}_k$)-fuzzy right ideal of a semigroup. Special sets, so called $Q^{\delta}_k$-set and $[{\lambda}^{\delta}_k]_t$-set, condition for the $Q^{\delta}_k$-set and $[{\lambda}^{\delta}_k]_t$-set-set to be left (resp. right) ideals are considered. We finally characterize different classes of semigroups (regular, left weakly regular, right weakly regular) in term of (${\in},{\in}{\vee}q^{\delta}_k$)-fuzzy left ideal, (${\in},{\in}{\vee}q^{\delta}_k$)-fuzzy right ideal and (${\in},{\in}{\vee}q^{\delta}_k$)-fuzzy ideal of semigroup S.

• The Pure and Applied Mathematics
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• v.14 no.3
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• pp.139-151
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• 2007

We introduce the concept of intuitionistic fuzzy semiprimality of a semigroup which is an extension of semiprimality in it. And we obtain a characterization of a semigroup that is a semilattice of simple semigroups in terms of intuitionistic fuzzy semiprime interior ideals.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.12 no.3
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• pp.215-225
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• 2012

We initiate the study of interval-valued fuzzy quasi-ideal of a semigroup. In Section 2, we list some basic definitions in the later sections. In Section 3, we investigate interval-valued fuzzy subsemigroups and in Section 4, we define interval-valued fuzzy quasi-ideals and establish some of their basic properties. In Section 5, we obtain characterizations of regular and intraregular semigroups using the machinery developed in the preceding sections.

• Journal of applied mathematics & informatics
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• v.10 no.1_2
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• pp.131-143
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• 2002

In this paper hi-criterion quadratic fractional generalized solid transportation problem is studied. An algorithm is developed to obtain the time-cost trade-off pairs and hence identifies the optimum trade-off pairs giving the equal priority to both time and cost. A numerical example is illustrated to support the algorithm.

• Nutritional Sciences
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• v.7 no.4
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• pp.241-246
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• 2004

This study investigated the influence of weight perception on weight management strategies including diet and exercise in Korean female adolescents. Junior (J) and senior (S) high school girls were divided in two groups; those who had $\leq$100% (BI) and > 100% (AI) of ideal weight (J-BI, n=376, 14.8 yr, 46.1 kg; J-AI, 11=128, 15.0 yr, 57.4 kg; S-BI, n=325, 17.4 yr, 50.1 kg; and S-AI, n=133, 17.5 yr, 58.2 kg, mean values). Questionnaires to assess weight perception, desire to lose weight, body image, eating behavior, weight control strategies and physical activity (PPA) were administered J-AI(9.4 kg) and S-AI(9.8 kg) desired to lose weight more than J-BI(2.5 kg) and S-BI(3.6 kg), respectively (p < 0.001). 85% of J-AI and 93% of S-AI perceived their weight being above average and 23% of J-BI and 34% of S-BI responded similarly (p < 0.001). Body dissatisfaction index (BDI) and eating attitude (EAT26) scores were lower in J-BI(9.7, 12.0) vs. J-AI(16.4, 14.7) and S-BI(12.4, 12.4) vs. S-AI(19.5, 15.4) (p < 0.001). However, PPA was not different for J-BI vs. J-AI, and S-BI vs. S-AL Only 17, 18, 9, and 15% of J.BI, J.AI, S-BI, and S-AI, respectively, exercised regularly. PPA and BDI were only slightly correlated in J-BI(r=0.194, p < 0.005) and S-BI(r=0.220, p < 0.005). Even that the majority of Korean female adolescents perceived they were heavy and desired to lose weight, appropriate exercise and physical activities were not practiced.

• Economic and Environmental Geology
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• v.39 no.6 s.181
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• pp.643-651
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• 2006

The Pb-Ag-Bi-S system minerals such as galena-matildite solid solutions, cosalite and heyrovskyite occur in the Nakdong As-Bi deposits. Galena-matildite solid solutions commonly coexisting with native bismuth fill in microfractures of pyrite grains and form irregular shapes. Cosalite forms composite grains including native bismuth, heyrovskyite and Bi-Te-S system minerals in the matrix of quartz vein. Matildite from the Nakdong deposits has an end member composition, $Ag_{1.07-1.11}Bi_{1.12-1.20}S_2$, and an excess concentration of $0.3{\sim}2.4$ mole % $Bi_2S_3$ compared to the stoichiomeoic value. PbS concentrations in $PbS-AgBiS_2$ solid solutions do not exceed 54 mole %. The average chemical composition of cosalite in the study area is $Pb_{1.79}Bi_{2.29}Ag_{0.12}S_5$. Pb is slightly depleted compared to the ideal composition, but the concentrations of Ag and Cu reach as much as 1.47 wt.% and 0.27 wt.%, respectively. Heyrovskyite has the chemical formula of $Pb_{5.01}Ag_{0.26}Bi_{2.70}S_9$ suggesting that there occurs the coupled substitution of $2Bi^{3+}$ for $3Pb^{2+}$ as well as that of $Ag^++Bi^{3+}$ for $2Pb^{2+}$. The genetic condition of Pb-Ag-Bi-S system minerals can be confined to the temperature of $220{\sim}270^{\circ}C$ and the pressure below 200 bars.