Dynamic routing under recurrent and non-recurrent congestion using real-time ITS information

In just-in-time (JIT) manufacturing environments, on-time delivery is a key performance measure for dispatching and routing of freight vehicles. Growing travel time delays and variability, attributable to increasing congestion in transportation networks, are greatly impacting the efficiency of JIT logistics operations. Recurrent and non-recurrent congestion are the two primary reasons for delivery delay and variability. Over 50% of all travel time delays are attributable to non-recurrent congestion sources such as incidents. Despite its importance, state-of-the-art dynamic routing algorithms assume away the effect of these incidents on travel time. In this study, we propose a stochastic dynamic programming formulation for dynamic routing of vehicles in non-stationary stochastic networks subject to both recurrent and non-recurrent congestion. We also propose alternative models to estimate incident induced delays that can be integrated with dynamic routing algorithms. Proposed dynamic routing models exploit real-time traffic information regarding speeds and incidents from Intelligent Transportation System (ITS) sources to improve delivery performance. Results are very promising when the algorithms are tested in a simulated network of South-East Michigan freeways using historical data from the MITS Center and Traffic.com.     

ROBUST ADAPTIVE CONTROL FOR STRICT‐FEEDBACK NONLINEAR SYSTEMS

In this paper, we propose a robust adaptive tracking control based on the backstepping strategy for strict‐feedback nonlinear systems with nonparametric uncertain nonlinearities. It is shown that one can design a stable adaptive control system provided that the uncertain nonlinearities can be decomposed by unknown bounded nonlinear functions and known nonlinear functions. The proposed method can deal with uncertain nonlinearities that appear at the control input term too. It is also shown that suitable choice of design parameters guarantees the convergence of tracking error to any desired bound.     

Task-based optimization and performance assessment in optical coherence imaging

Optimization of an optical coherence imaging (OCI) system on the basis of task performance is a challenging undertaking. We present a mathematical framework based on task performance that uses statistical decision theory for the optimization and assessment of such a system. Specifically, we apply the framework to a relatively simple OCI system combined with a specimen model for a detection task and a resolution task. We consider three theoretical Gaussian sources of coherence lengths of 2, 20, and 40 microm. For each of these coherence lengths we establish a benchmark performance that specifies the smallest change in index of refraction that can be detected by the system. We also quantify the dependence of the resolution performance on the specimen model being imaged.     

Molecularly inherent voltage-controlled conductance switching

Molecular electronics has been proposed as a pathway for high-density nanoelectronic devices. This pathway involves the development of a molecular memory device based on reversible switching of a molecule between two conducting states in response to a trigger, such as an applied voltage. Here we demonstrate that voltage-triggered switching is indeed a molecular phenomenon by carrying out studies on the same molecule using three different experimental configurations-scanning tunnelling microscopy, crossed-wire junction, and magnetic-bead junction. We also demonstrate that voltage-triggered switching is distinctly different from stochastic switching, essentially a transient (time-dependent) phenomenon that is independent of the applied voltage.     

The delayed action of magnesium anodes in primary batteries: Part II. Theoretical studies

A physical model for the field-induced breakdown of the passive film on magnesium anodes has been developed based on experimental data on the delayed action of magnesium anodes. The model essentially involves, successively, metal dissolution at the metal-film interface, film-dilatation, and film breakdown. A theoretical analysis of the model has been carried out to obtain an explicit expression for the time dependence of the electrode potential during the delayed action phenomenon. The delay-time curves obtained are compared with experimental data, especially with regard to the effects of film thickness, ageing of the anode in solution, current density, temperature, etc. Finally, possible means of reducing the delayed action of magnesium anodes are predicted from the ‘metal dissolution-film dilatation-film breakdown’ model.     

Reduction of U15 representations into SU3 irreducible components

The irreducible representations of U₃ contained in a given partition of U₁₅ are calculated by means of the plethysm of S-functions. The results are given for partitions of up to ten boxes.     

Moisture diffusion through nanoclay/vinylester processed using twin‐screw extrusion

This research concerns moisture absorption through nanoclay/vinylester composites in artificial seawater medium and the resulting properties of degradation. Cloisite 15A, an organomodified nanoclay, and Cloisite Na, a naturally occurring nanoclay, were studied to examine the influence of organomodification on the moisture ingress behavior of the nanocomposites processed by using ultrasonication and twin‐screw extrusion. Although X‐ray diffraction and transmission electron microscopy analysis revealed exfoliation of Cloisite 15A in vinylester, Cloisite Na was only intercalated. Moisture diffusivity decreased by 72% due to the addition of 5 wt% of Cloisite 15A to vinylester. However, the same increased in the case of the addition of Cloisite Na, suggesting a positive influence of the organomodification on the moisture barrier properties. Although Fick's Law of Diffusion showed deviation from the experimental data in the nonlinear region of moisture absorption as a function of duration of exposure, the Langmuir Model was in better agreement with the experimental data in the entire range. (Cloisite 15A)/vinylester showed lower levels of microhardness deterioration due to moisture absorption than that of (Cloisite Na)/vinylester. J. VINYL ADDIT. TECHNOL., 20:152–159, 2014. © 2014 Society of Plastics Engineers     

Repetitive Corrugation and Straightening of Sheet Metals

Recently, severe plastic deformation (SPD) techniques have been gaining wide popularity in developing nano/ultrafine grained (UFG) structured materials for a wide variety of applications. Among SPD techniques, there are a few techniques that are specially used to process metallic sheets and plates. Repetitive corrugation and straightening (RCS) is one such promising technique, which can produce fine grained structures in metallic sheets or plates in bulk. The process was introduced to develop UFG metallic sheets and plates nearly a decade ago and is now gaining great interest in the material processing field. The aim of the present review is to give a comprehensive summary of the state-of-the-art of the process in developing fine grained structured sheets. Emphasis has been given to discuss different material systems processed by RCS. The mechanism behind the grain refinement during RCS, promising applications, and future perspectives in developing UFG structured sheets or plates by RCS are also discussed.