• Korean Journal of Mathematics
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• v.14 no.1
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• pp.71-77
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• 2006

We find the ${\epsilon}$-fuzzy equivalence relation generated by the union of two ${\epsilon}$-fuzzy equivalence relations on a set, find the ${\epsilon}$-fuzzy equivalence relation generated by a fuzzy relation on a set, and find sufficient conditions for the composition ${\mu}{\circ}{\nu}$ of two ${\epsilon}$-fuzzy equivalence relations ${\mu}$ and ${\nu}$ to be the ${\epsilon}$-fuzzy equivalence relation generated by ${\mu}{\cup}{\nu}$. Also we study fuzzy partitions of ${\epsilon}$-fuzzy equivalence relations.

• International Journal of Reliability and Applications
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• v.9 no.1
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• pp.79-93
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• 2008

The aim of this work is to generalize reliability equivalence techniques to apply them to a system consists of two independent and non-identical components connected in series(parallel) system, that have constant failure rates. We shall improve the system by using one component only. We start by establishing two different types of reliability equivalence factors, the survival reliability equivalence (SRE) and mean reliability equivalence (MRE) factors. Our second studies, introducing some applications for our studies in airports and our life. Also, we introduced some numerical results.

• Korean Journal of Mathematics
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• v.15 no.1
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• pp.59-69
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• 2007

We define an extended fuzzy equivalence relation, discuss some basic properties of extended fuzzy equivalence relations, find the extended fuzzy equivalence relation generated by a fuzzy relation in a set, and give some lattice theoretic properties of extended fuzzy equivalence relations.

• Korean Journal of Mathematics
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• v.11 no.2
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• pp.169-175
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• 2003

We find a G-fuzzy equivalence relation generated by the union of two G-fuzzy equivalence relations in a set, find a G-fuzzy equivalence relation generated by a fuzzy relation in a set, and find sufficient conditions for the composition ${\mu}{\circ}{\nu}$ of two G-fuzzy equivalence relations ${\mu}$ and ${\nu}$ to be a G-fuzzy equivalence relation generated by ${\mu}{\cup}{\nu}$.

• Journal of the Korean Mathematical Society
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• v.33 no.3
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• pp.685-692
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• 1996

Subshifts of finite type can be classified by various equivalence relations. The most important equivalence relation is undoubtedly strong shift equivalence, i.e., conjugacy. In [W], R. F. Williams introduced shift equivalence which is weaker than conjugacy but still sensitive.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.5
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• pp.35-44
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• 2011

In a spark ignition engine, a variable valve lift (VVL) system has been developed for high fuel efficiency and low power loss. However, changes in valve lift cause deviations of cylinder air charge which lead to individual cylinder equivalence ratio maldistribution. In this study, in order to reduce the maldistribution, we propose individual cylinder equivalence ratio estimation and control algorithms. The estimation algorithm calculates the equivalence ratio of each cylinder by using a mathematical engine model which includes air charging, fuel film, exhaust gas, and universal exhaust gas oxygen sensor (UEGO) dynamics at various valve lifts. Based on the results of estimated equivalence ratio, the injection quantity of each cylinder is adjusted to control the individual cylinder equivalence ratio. Estimation and control performance are validated by engine experiments. Experimental results represented that the equivalence ratio maldistribution and variation are decreased by the proposed algorithms.

• Journal of the Korean Mathematical Society
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• v.57 no.2
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• pp.383-399
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• 2020

Following Matsumoto's definition of continuous orbit equivalence for one-sided subshifts of finite type, we introduce the notion of orbit equivalence to canonically associated dynamical systems, called the limit dynamical systems, of self-similar groups. We show that the limit dynamical systems of two self-similar groups are orbit equivalent if and only if their associated Deaconu groupoids are isomorphic as topological groupoids. We also show that the equivalence class of Cuntz-Pimsner groupoids and the stably isomorphism class of Cuntz-Pimsner algebras of self-similar groups are invariants for orbit equivalence of limit dynamical systems.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.9 no.1
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• pp.20-29
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• 2009

In this paper, by using the definition of fuzzy equivalence relations introduced by Dib and Youssef, we obtain fuzzy analogues of many results concerning ordinary equivalence relations. Moreover, we investigate fuzzy analogues of many results concerning relationships between ordinary equivalence relations and ordinary functions. In particular, we obtain the fuzzy-canonical decomposition of a fuzzy function.

• Cross-Cultural Studies
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• v.19
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• pp.251-270
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• 2010

The subject of the paper is to discern the validity of the translation theory put forward by the ESIT(Ecole Sup?rieur d'Interpr?tes et de Tranducteurs, Universit? Paris III) and how it differentiates from the other translation theories. First, the paper will analyze the theoretical aspects put forward by examining the equivalence that may be discerned between the french and korean translation in relation to the original english text that is being translated. Employing the equivalence in translation may shed new insights into the unterminable discussions we witness today between the literal translation and the free translation. Contrary to the formal equivalence the dynamic equivalence by Nida suggests that the messages retain the same meanings whether it be the original or a translated text to the/for the reader. In short, the object of the dynamic equivalence is to identify the closest equivalence to the suggested source language. The concept of correspondence and equivalence defined by theoriticians of translation falls to the domain of dynamic equivalence suggested by Nida. In translation theory the domain of usage of language and the that of discourse is denoted separately. by usage one denotes the translation through symbols that make up language itself. In contrast to this, the discourse is suggestive of defining the newly created expressions which may be denoted as being a creative equivalence which embodies the original message for the singular situation at hand. The translator will however find oneself incorporating the two opposing theories in translating. Translation falls under the criteria of text and not of language, thus one cannot regulate or foresee any special circumstances that may arise in translation of discourse, the translation to reflect this condition should always be delimited. All other translation should be subject to translation by equivalence. The interpretation theory in translation (of ESIT) in effect is relative to both the empirical and philosophical approach and is suggestive of new perspective in translation. In conclusion, the above suggested translation theory is different from the skopos theory and the polysystem theory in that it only takes in to account the elements that are in close relation to the original text, and also that it was developed for educational purposes opening new perspectives in the domain of translation theories.

• Journal of the Korean Society of Combustion
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• v.16 no.3
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• pp.52-58
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• 2011

The purpose of this paper is to investigate the effect of equivalence ratio on the combustion and emission characteristics of a compression ignition engine fueled with biodiesel. In this research, a single-cylinder direct injection engine with 373.3 cc of displacement volume was tested on DC dynamometer. In order to investigate the effect of biodiesel equivalence ratio on combustion characteristics, the experiments were conducted at various equivalence ratios and injection pressures of 40~120 MPa. For investigating engine performance, lambda meter was connected and equivalence ratios was varied from 0.6 to 1.0. In addition, the exhaust emissions such as oxides of nitrogen($NO_X$), hydrocarbon(HC) and carbon monoxide(CO) were measured by exhaust gas analyzer under the various air/fuel ratios. The experimental results show that maximum IMEP was measured at the 0.8 of equivalence ratio. Furthermore, $NO_X$ emission was rapidly decreased as the increase of equivalence ratio. However soot emission was significantly increased according to the increase of equivalence ratio.