Space-time behavior-based correlation-Or-how to tell if two underlying motion fields are similar without computing them?

We introduce a behavior-based similarity measure which tells us whether two different space-time intensity patterns of two different video segments could have resulted from a similar underlying motion field. This is done directly from the intensity information, without explicitly computing the underlying motions. Such a measure allows us to detect similarity between video segments of differently dressed people performing the same type of activity. It requires no foreground/background segmentation, no prior learning of activities, and no motion estimation or tracking. Using this behavior-based similarity measure, we extend the notion of 2-dimensional image correlation into the 3-dimensional space-time volume, thus allowing to correlate dynamic behaviors and actions. Small space-time video segments (small video clips) are "correlated" against entire video sequences in all three dimensions (x,y, and t). Peak correlation values correspond to video locations with similar dynamic behaviors. Our approach can detect very complex behaviors in video sequences (e.g., ballet movements, pool dives, running water), even when multiple complex activities occur simultaneously within the field-of-view of the camera. We further show its robustness to small changes in scale and orientation of the correlated behavior.     

Swelling and photoelastic behaviour of ionized hydrogels of poly(acrylic acid)

Summary The photoelastic and swelling behaviour of poly(acrylic acid) gels swollen in 1 M NaCl aqueous solution was studied as a function of crosslinking degree (1–5 wt.% ethylene glycol dimethacrylate) and degree of ionization _g = 0 – 1. The degree of swelling passes through a minimum at _g – 0.15 regardless of the degree of crosslinking, probably due to the formation of hydrogen bonds between ionized and nonionized carboxyl groups. In the same neutralization region, the equilibrium modulus reaches a maximum; on the other hand, the modulus related to the dry state is independent of for all crosslinker concentrations. Thus the mechanical behaviour of poly(acrylic acid) gels is in accord with the Gaussian theory and no contribution of permanent physical interactions to the modulus is observed. The optical behaviour is more complex — the sign of the stress-optical coefficient C _e changes three times with increasing due to the orientation of the side groups. The analysis of the optical data shows that the C _e value is controlled by the degree of swelling and by the ionization.     

Production and biological activity of saponins and canavanine in alfalfa seedlings

The saponin and canavanine concentrations and pattern were analyzed in growing alfalfa seedlings (Medicago sativa L.). Accumulation of saponins and canavanine was found to follow different time courses. During the first eight days, saponin concentration rose from zero in alfalfa seeds to 8.7% in roots and 1.8% in shoots on eighth day and then slowly decreased to 7.6% in roots and 0.8% in shoots present on the 24th day. Canavanine was found in seeds at a concentration of 1 % then increased to 3.2% in seedlings on the sixth day and rapidly decreased to 0.2% per dry mass in roots and shoots on the 24th day. The effect of saponins-medicagenic acid sodium salt and medicagenic acid glycosides-on the growth ofAmaranthus andLepidium in Petri dishes and tomato (Lycopersicon) cell growth in tissue culture also was investigated. In contrast to medicagenic acid glycosides, a very strong inhibition of plant and cell growth was found as an effect of medicagenic acid.     

Manifestations of user personality in website choice and behaviour on online social networks

Individual differences in personality affect users’ online activities as much as they do in the offline world. This work, based on a sample of over a third of a million users, examines how users’ behaviour in the online environment, captured by their website choices and Facebook profile features, relates to their personality, as measured by the standard Five Factor Model personality questionnaire. Results show that there are psychologically meaningful links between users’ personalities, their website preferences and Facebook profile features. We show how website audiences differ in terms of their personality, present the relationships between personality and Facebook profile features, and show how an individual’s personality can be predicted from Facebook profile features. We conclude that predicting a user’s personality profile can be applied to personalize content, optimize search results, and improve online advertising.     

Utilising the chaos-induced discrete self organising migrating algorithm to solve the lot-streaming flowshop scheduling problem with setup time

The Dissipative Lozi chaotic map is embedded in the discrete self organising migrating algorithm (DSOMA), as a pseudorandom generator. This novel chaotic based algorithm is applied to the constraint based lot-streaming flowshop scheduling problem. Two new and unique data sets generated using the Lozi and Delayed Logistic maps are used to compare the chaos embedded DSOMA and the generic DSOMA utilising the venerable Mersenne Twister. In total, 100 data sets were tested by these two algorithms, for the idling and the non-idling case. From the obtained results, the chaos variant algorithm is shown to significantly improve the performance of generic DSOMA.     

Predicting leucine zipper structures from sequence

The leucine zipper structure is adopted by one family of thecoiled coil proteins. Leucine zippers have a characteristicleucine repeat: Leu–X₆–Leu–X₆–Leu–X₆–Leu(where X may be any residue). However, many sequences have theleucine repeat, but do not adopt the leucine zipper structure(we shall refer to these as non-zippers). We have found andanalyzed residue pair patterns that allow one to identify correctly90% of leucine zippers and 97% of non-zippers. Simpler analyses,based on the frequency of occurrence of residues at certainpositions, specify, at most, 65% of zippers and 80–90%of non-zippers. Both short and long patterns contribute to thesuccessful discrimination of leucine zippers from non-zippers.A number of these patterns involve hydrophobic residues thatwould be placed on the solvent-exposed surface of the helix,were the sequence to adopt a leucine zipper structure. Thus,an analysis of protein sequences has allowed us to improve discriminationbetween leucine zippers and non-zippers, and has provided somefurther insight into the physical factors influencing the leucinezipper structure.     

The multilocation transshipment problem

We consider a supply chain, which consists of several retailers and one supplier. The retailers, who possibly differ in their cost and demand parameters, may be coordinated through replenishment strategies and transshipments, that is, movement of a product among the locations at the same echelon level. We prove that in order to minimize the expected long-run average cost for this system, an optimal replenishment policy is for each retailer to follow an order-up-to S policy. Furthermore, we demonstrate how the values of the order-up-to quantities can be calculated using a sample-path-based optimization procedure. Given an order-up-to S policy, we show how to determine an optimal transshipment policy, using a linear programming/network flow framework. Such a combined numerical approach allows us to study complex and large systems.     

Alternating biasing of SDT sensors

The spin dependent tunneling (SDT) effect has been observed in thin ferromagnetic multilayer structures. In general, two ferromagnetic layers are separated by a very thin non-conductive layer. In dependence on the angle between the magnetization of the upper and the lower ferromagnetic layer, electrons tunnel through the non-conductive barrier layer. We made experiments with an SDT sensor fabricated by NVE Corporation. Four elements in the bridge configuration are used in the sensor structure. One ferromagnetic layer of each element is pinned by an anti-ferromagnetic layer. The so-called orthogonal biasing can be applied in this sensor type. We also tried to study the possibilities of ac biasing techniques in the SDT sensors of this type.     

Language and Compiler Design for Streaming Applications

High-performance streaming applications are a new and distinct domain of programs that is increasingly important. The StreamIt language provides novel high-level representations to improve programmer productivity and program robustness within the streaming domain. At the same time, the StreamIt compiler aims to improve the performance of streaming applications via stream-specific analysis and optimizations. In this paper, we motivate, describes and justify the StreamIt language which include a structured model of streams, a messaging system for control, and a natural textual syntax.     

Stabilizing low complexity feedback control of constrained piecewise affine systems

Piecewise affine (PWA) systems are powerful models for describing both non-linear and hybrid systems. One of the key problems in controlling these systems is the inherent computational complexity of controller synthesis and analysis, especially if constraints on states and inputs are present. In addition, few results are available which address the issue of computing stabilizing controllers for PWA systems without placing constraints on the location of the origin.This paper first introduces a method to obtain stability guarantees for receding horizon control of discrete-time PWA systems. Based on this result, two algorithms which provide low complexity state feedback controllers are introduced. Specifically, we demonstrate how multi-parametric programming can be used to obtain minimum-time controllers, i.e., controllers which drive the state into a pre-specified target set in minimum time. In a second segment, we show how controllers of even lower complexity can be obtained by separately dealing with constraint satisfaction and stability properties. To this end, we introduce a method to compute PWA Lyapunov functions for discrete-time PWA systems via linear programming. Finally, we report results of an extensive case study which justify our claims of complexity reduction.