When modeling time series data using autoregressive-moving average processes, it is a common practice to presume that the residuals are normally distributed. However, sometimes we encounter non-normal residuals and asymmetry of data marginal distribution. Despite widespread use of pure autoregressive processes for modeling non-normal time series, the autoregressive-moving average models have le...

Since its introduction to recognize chordal graphs by Rose, Tarjan, and Lueker, Lexicographic Breadth First Search (LexBFS) has been used to come up with simple, often linear time, algorithms on various classes of graphs. These algorithms, called multi-sweep algorithms, compute a number of LexBFS orderings σ1, . . . , σk, where σi is used to break ties for σi+1, we write LexBFS (σi) = σi+1. For...

in this paper, in order to optimize the portfolio consisting of selected industrial stocks of petroleum products, automobiles and parts, electrical industry and extraction of minerals from tehran stock exchange member, first, time – varying conditional covariance matrix has been estimated based on the following multivariate garch models: diagonal-vech (1,1), ccc (1,1) and diagonal -bekk (1,1). ...

biosorption of acidic dyes using the live fern azolla filliculoides was studied in a discontinuous system. dye parameters, dye initial concentration and contact time were studied in temperature range of 25-30 ?c and ph=7. it was shown that increasing the 23initial concentration of dye and its contact time resulted in decreasing the dye taking quantity by the absorbent. also, type of dye has an ...

xylariaceous fungi are typically saprobes, but are also commonly isolated as endophytes and some species are pathogens. two species of lopadostoma (xylariaceae, xylariales) are reported for the first time from iran. l. dryophilum was found from dead branches of quercus sp. in east azerbaiejan and l. fagi from dead branches of fagus sp. in ardabil province. based on morphology and sequence data ...

abstractthe purpose of this study was to investigate the controllable operating parameters influence, including ph, solid content, collector, co-collector, and depressant dose, and conditioning time, on apatite flotation kinetics. four first order flotation kinetic models are tested on batch flotation time-recovery profiles. the results of batch flotation tests and the fitting of first-order ki...

The paper concerns the development of a new adaptive PI controller for use in HVAC systems. The process of HVAC control can be described as a first order plus dead time model. A kind of arithmetic of recursive least squares (RLS) with exponential forgetting combined with model matching of a zero frequency method is adopted to estimate the model’s parameters while the system remained in closed l...