Based on a new hesitant fuzzy partial ordering proposed by Garmendia et al. [7], in this paper a fuzzy disjunction D on the set H of finite and nonempty subsets of the unit interval and a t-conorm S on the set  B of equivalence class on the set of finite bags of unit interval based on this partial ordering are introduced respectively. Then, hesitant fuzzy negations Nn on H and  n on  B are proposed. Particularly, their De Morgan’ s laws are investigated with respect to binary operations C and D on H, as well as T and S on  B respectively, where C is a commutative fuzzy conjunction on (H;  H) and T is a t-norm on ( B;  B). Finally, the new hesitant fuzzy aggregation operators are presented on H and  B and their more general forms are given. Moreover, the validity of the aggregation operations is illustrated by a numerical example on decision making.

In this paper, we introduce a new class of (semi)hypergroup from a given (partially) quasi-ordered (semi) hypergroup as a generaliza- tion of "El-hyperstructures". Then, we study some basic properties and important elements belong to this class.

The present research studies the derivational suffixes ordering constraints in Persian in Complexity-based ordering Approach. The corpus based on which this research is conducted is the data of the Institute for Humanities and Cultural Studies. To conduct this study, 8 Persian suffixes were selected and ranked in a hierarchy-based ordering in Complexity-based ordering Approach, then the correlation between their ranks in the hierarchy and their productivity, parsing ratios and boundary strengths were evaluated. Also, the correlation between the suffixes positions in graphical hierarchy, with their productivity, parsing ratios and boundary strengths were evaluated. The results show that there is no meaningful correlation between the suffixes ranks in the hierarchy-based ordering in Complexity-based ordering Approach and their position in the graphical hierarchy, their productivity, parsing ratios and boundary strengths.

Affix ordering is a theoretical discussion in morphology. Till now, three approaches considered affix ordering such as layered approach (siegel 1974), Selectional restriction approach (Fabb 1988) and complexity-based ordering approach (Hay and Plag 2000). The Complexity-Based ordering create the present theoretical framework article. The purpose of this research is assessing this approach in Persian derivational suffix ordering. For this end, about 41 Persian derivational suffixes are selected. Then from the Persian corpus of the Institute of Humanities and Cultural Studies 9172 derivative words is extracted. The results show that there is a covering between parsability continuum and Persian suffix ordering in the most cases. But this covering is not complete and, in some cases, parsability can’ t describe some of the derivate combinations. According to Hay and Plag (2004), It seems that for presenting a description of Persian suffix ordering beside parsability we must consider the Selectional restriction on affixes.

Topological aspects of meshless element free Galerkian method (EFGM) as the nodal connectivity of matrices are studied. Four different graphs are defined for meshless discretizations of EFGM and their connectivity is investigated. Graphs are used for nodal ordering of meshless models in order to reduce the bandwidth, profile, maximum front width, and root-mean-square wave front of the corresponding matrices.      

The topological ordering algorithm sorts nodes of a directed graph such that the order of the tail of each arc is lower than the order of its head. In this paper, we introduce the notion of covering between nodes of a directed graph. Then, we apply the topological ordering algorithm on graphs containing the covering nodes. We show that there exists a cut set with forward arcs in these graphs and the order of the covering nodes is successive.

In this paper, we compare four ordering policies in a lost sales inventory model with zero ordering cost, constant lead time, and Poisson demand process. These ordering policies are 1) base stock policy, 2) full delay policy, 3) simple delay policy and 4) a recently developed ordering policy called (1; T) or one for one period policy. Our work can be considered as an expansion of a previous research which compared the first three policies. We show that, for any fixed value of the ratio of unit lost sales cost over unit holding cost, there is a specific value of lead time demand beyond which the cost of (1; T) policy is lower than the costs of the other three policies. Furthermore, the superiority of (1; T) policy is more significant for low values of the above ratio and becomes more pronounced as the lead time demand increases.