Survival data may include two different sources of variation, namely variation over time and variation over units. If both of these variations are present, neglecting one of them can cause serious bias in the estimations. Here we present an approach for discrete duration data that includes both time-varying and unit-specific effects to model these two variations simultaneously. The approach is ...

The dynamic model of a drill in drilling process was proposed and investigated in this study. To assure a good drilling quality, the vibration variation on the drill tips during high speed drilling is needed to be investigated. A pre-twisted beam is used to simulate the drill. The moving Winkler-Type elastic foundation is used to characterize the tip boundary variation in drilling. Due to the v...

Because natural organisms are a part of the factors constituting the ecosystem for each organism, it is important to clarify both physical and biological exploitable factors to determine species compositions which exist in that ecosystem. The variation in factors which constitute an ecosystem makes up the variation in species composition. At the same time, each species will interact and will ma...

the crankshaft is one of the most critically loaded components as it experiences cyclic loads in the form of bending and torsion during its service life. its failure will cause serious damage to the engine so it’s important at the time of design to verify fatigue strength. more challenges in crankshaft design due to increasing vehicle payloads, lower weight requirement, higher efficiency and lo...

in this paper, nonlinear dynamic behaviours of carbon nanotube conveying fluidwith slip boundary conditions is studied using variation iteration method. the developed solutions are used to investigate the effects of various parameters on the nonlinear vibration of the nanotube. from the result, it is observed that increase in the slip parameter leads to decrease in the frequency of vibration an...

in this paper, the concept of conjectural variation (cv) is used to specify optimal generation decision for generation companies (gencos). the conjecture of genco is defined as its belief or expectation about the reaction of rivals to change of its output. using cv method, each genco has to learn and estimate strategic behaviors of other competitors from available historical market operation da...

in this paper, a novel approach for control of the dc-dc buck converter in high-power and low-voltage applications is proposed. designed method is developed according to state feedback linearization based controller , which is able to stabilize output voltage in a wide range of operation. it is clear that in high-power applications, parasitic elements of the converter may become comparable with...

Representation and classification of dynamic visual events in videos have been an active field of research. This work proposes a novel spatio-temporal descriptor based on phase congruency concept and applied it to recognize facial expression from video sequences. The proposed descriptor comprises histograms of dominant phase congruency over multiple 3D orientations to describe both spatial and ...

This paper describes a new online convex optimization method which incorporates a family of candidate dynamical models and establishes novel tracking regret bounds that scale with the comparator’s deviation from the best dynamical model in this family. Previous online optimization methods are designed to have a total accumulated loss comparable to that of the best comparator sequence, and exist...