Locally Adaptive Block Thresholding Method with Continuity Constraint

We present an algorithm that enables one to perform locally adaptive block thresholding, while maintaining image continuity. Images are divided into sub-images based some standard image attributes and thresholding technique is employed over the sub-images. The present algorithm makes use of the thresholds of neighboring sub-images to calculate a range of values. The image continuity is taken care by choosing the threshold of the sub-image under consideration to lie within the above range. After examining the average range values for various sub-image sizes of a variety of images, it was found that the range of acceptable threshold values is substantially high, justifying our assumption of exploiting the freedom of range for bringing out local details.Comment: 12 Pages, 4 figures, 1 Tabl

Perceptions of medical professionals towards sustainability orientation and acceptability of eco-friendly medical scrubs

This research explores the perceptions of medical professionals towards sustainability orientation and acceptability of eco-friendly medical scrubs. This study examines the correlation between sustainability orientation and scrub properties as a means of finding the perceptions of medical professionals on the mentioned topic. Also, gender, department of medical professional, their age and work experience, and the price of the eco-friendly scrubs were considered as factors affecting the correlation. This study included surveying the medical professionals who used scrubs as uniforms, by distributing questionnaires and analyzing responses using SPSS. Results showed that as sustainability orientation increases, medical professionals give less importance to properties of scrubs. Gender and department of hospital they work in affects the correlation. Professionals with greater age and work experience are more sustainably oriented with greater acceptability of eco-friendly scrubs. And the majority of the medical professionals who participated in the study agreed to pay a higher price for the eco-friendly medical scrubs

Explicit finite element analysis of web-roller interaction in web process machinery

A web can be defined as thin material manufactured and processed in continuous flexible strip form. A web is usually supported, guided and propelled by rollers. In order to make it travel through the process machine line, sufficient external machine direction force and velocity must be applied to web. The work presented here studies the mechanics and associated instabilities of webs running over the rollers which are not perfectly cylindrical in shape. Lateral and longitudinal behavior of web on concave, crown and tapered roller is studied. The exact boundary conditions are established. Several roller geometries, web materials and webline conditions are modeled using explicit finite element method for analyzing web-roller interaction. Instabilities in the form of troughs and wrinkles induced as a result of imperfection such as roller crown and taper are also studied. The simulation results are compared with available closed form solutions and experiments documented by previous researchers. A satisfactory agreement is observed for deflection, stress and overall behavior of web on such contoured (non cylindrical) rollers. This study revealed that normal entry condition is valid at the entry of web to a contoured roller. It is also found that web does not slip over its wrap on roller surface till the very exit from roller surface. These findings were then used to formulate computer code that predicts web behavior quite satisfactorily utilizing very few computational resources and time

Control Synthesis for an Underactuated Cable Suspended System Using Dynamic Decoupling

This article studies the dynamics and control of a novel underactuated system, wherein a plate suspended by cables and with a freely moving mass on top, whose other ends are attached to three quadrotors, is sought to be horizontally stabilized at a certain height, with the ball positioned at the center of mass of the plate. The freely moving mass introduces a 2-degree of underactuation into the system. The design proceeds through a decoupling of the quadrotors and the plate dynamics. Through a partial feedback linearization approach, the attitude of the plate and the translational height of the plate is initially controlled, while maintaining a bounded velocity along the $y$ and $x$ directions. These inputs are then synthesized through the quadrotors with a backstepping and timescale separation argument based on Tikhonov's theorem

Adaptive Complex Contagions and Threshold Dynamical Systems

A broad range of nonlinear processes over networks are governed by threshold dynamics. So far, existing mathematical theory characterizing the behavior of such systems has largely been concerned with the case where the thresholds are static. In this paper we extend current theory of finite dynamical systems to cover dynamic thresholds. Three classes of parallel and sequential dynamic threshold systems are introduced and analyzed. Our main result, which is a complete characterization of their attractor structures, show that sequential systems may only have fixed points as limit sets whereas parallel systems may only have period orbits of size at most two as limit sets. The attractor states are characterized for general graphs and enumerated in the special case of paths and cycle graphs; a computational algorithm is outlined for determining the number of fixed points over a tree. We expect our results to be relevant for modeling a broad class of biological, behavioral and socio-technical systems where adaptive behavior is central.Comment: Submitted for publicatio

Order and Disorder in AKLT Antiferromagnets in Three Dimensions

The models constructed by Affleck, Kennedy, Lieb, and Tasaki describe a family of quantum antiferromagnets on arbitrary lattices, where the local spin S is an integer multiple M of half the lattice coordination number. The equal time quantum correlations in their ground states may be computed as finite temperature correlations of a classical O(3) model on the same lattice, where the temperature is given by T=1/M. In dimensions d=1 and d=2 this mapping implies that all AKLT states are quantum disordered. We consider AKLT states in d=3 where the nature of the AKLT states is now a question of detail depending upon the choice of lattice and spin; for sufficiently large S some form of Neel order is almost inevitable. On the unfrustrated cubic lattice, we find that all AKLT states are ordered while for the unfrustrated diamond lattice the minimal S=2 state is disordered while all other states are ordered. On the frustrated pyrochlore lattice, we find (conservatively) that several states starting with the minimal S=3 state are disordered. The disordered AKLT models we report here are a significant addition to the catalog of magnetic Hamiltonians in d=3 with ground states known to lack order on account of strong quantum fluctuations.Comment: 7 pages, 2 figure