Forecasting models have wide applications in decision making. In the real world, rapid changes normally take place in different areas, specifically in financial markets. Collecting the required data is a main problem for forecasters in such unstable environments. Forecasting methods such as Auto Regressive Integrated Moving Average (ARIMA) models and also Artificial Neural Networks (ANNs) need ...

this paper addresses the validity of two hypotheses concerning changes of vowel quality in persian. the theory of centralization claims that there is a strong correlation between vowel duration and vowel quality. as vowel duration is shortened in unstressed contexts, the size of the vowel inventory reduces toward the center, leading to considerable overlap between different categories and a red...

The existence of two frequency regimes in a two-dimensional (2D) Rosenzweig–MacArthur ecological network is debated. semi-discrete approximation differentiates the regimes, each described by 2D complex Ginzburg–Landau equation. Using standard theory linear stability analysis, generalized expression for modulational instability growth rate derived mode. parametric study reveals its sensitivity t...

Common experience suggests that attracting invariant sets in nonlinear dynamical systems are generally stable. Contrary to this intuition, we present a dynamical system, a network of pulse-coupled oscillators, in which unstable attractors arise naturally. From random initial conditions, groups of synchronized oscillators (clusters) are formed that send pulses alternately, resulting in a periodi...

Measured by harmonic tests, the viscoelastic properties of Chinese fir during moisture sorption processes were examined under three relative humidity (RH) modes: RHramp, RHisohume, and RHstep. The stiffness decreased and damping increased as a function of the moisture content (MC), which is presumed to be the effect of plasticization and an unstable state. The increasing damping was associated ...

Wireless sensor networks receive much attention in these few years due to its wide spectrum of applications. Localization is one of the significant techniques in the ubiquitous sensor networks, and most localization techniques nowadays apply RSSI-based ranging techniques to compute the location of the object in wireless sensor network. However, a wireless sensor network is of a fading-signal en...

Wireless sensor networks have received a lot of attention in recent years due to their wide spectrum of applications. Localization a technique used in ubiquitous sensor networks. Most localization techniques apply RSSI-based ranging techniques to compute the location of the object in a wireless sensor network. However, a wireless sensor network is a fading-signal environment that has noise, whi...