in some data envelopment analysis (dea) applications, some inputs of dmus have negative values with positive cost. this paper generalizes the global cost malmquist productivity index to compare the productivity of dierent dmus with negative inputs in any two periods of times under variable returns to scale (vrs) technology, and then the generalized index is decomposed to several components. th...

the present note is devoted to establish some extremal results for the zeroth-order general randi'{c} index of cacti, characterize the extremal polyomino chains with respect to the aforementioned index, and hence to generalize two already reported results.

in this paper, a new molecular-structure descriptor, the general sum–connectivity co–index  is considered, which generalizes the first zagreb co–index and the general sum–connectivity index of graph theory. we mainly explore the lower and upper bounds in termsof the order and size for this new invariant. additionally, the nordhaus–gaddum–type resultis also represented.

In this paper, we study the inflationary scenario in realm of k-essence model and swampland conjectures. Taking into account three models Chaplygin gas, such as generalized, modified, generalized cosmic gas models, discuss equation state (EoS) parameter ω, slow roll parameters (ϵ(ϕ),η(ϕ)), curvature perturbation (Ps), tensor to scalar ratio (r), spectral index (ns). As regards model, coupling f...

The aim of this study was to investigate the asymmetric effects of exchange rate fluctuations on Stock index of Tehran Stock Exchange. For this purpose, we first calculated the exchange rate fluctuations using model General Autoregressive Conditional Heteroskedastic (GARCH), and then the effect of these fluctuations on the Stock index of Tehran Stock Exchange was estimated using the Generalized...

In some data envelopment analysis (DEA) applications, some inputs of DMUs have negative values with positive cost. This paper generalizes the global cost Malmquist productivity index to compare the productivity of dierent DMUs with negative inputs in any two periods of times under variable returns to scale (VRS) technology, and then the generalized index is decomposed to several components. The...

A new algorithm for ray tracing generalized cylinders whose axis is an arbit:rary three dimensional space curve and whose cross-sectional contour can be varied accortding to a general sweeping rule is presented. The only restriction placed on the class of generalized cylinders that can be ray-traced is that the sweeping rule of the generalized cylinder must be invertible. This algorithm handles...

Generalized adaptive notch filters are used for identification/tracking of quasi-periodically varying dynamic systems and can be considered an extension, to the system case, of classical adaptive notch filters. For general patterns of frequency variation the generalized adaptive notch filtering algorithms yield biased frequency estimates. We show that when system frequencies change slowly in a ...

In theoretical chemistry, -modified Wiener index is a graph invariant topological index to analyze the chemical properties of molecular structure. In this note, we determine the minimum -modified Wiener index of graph with fixed connectivity or edge-connectivity. Our results also present the sufficient and necessary condition for reaching the lower bound.

Missing values occur in studies of various disciplines such as social sciences, medicine, and economics. The missing mechanism in these studies should be investigated more carefully. In this article, some models, proposed in the literature on longitudinal data with dropout are reviewed and compared. In an applied example it is shown that the selection model of Hausman and Wise (1979, Econometri...