Object segmentation in cluttered and visually complex environments

Object segmentation is essential for systems that acquire object models online for robotic grasping. However, it remains a major technical challenge in visually complex and uncontrolled environments. Segmentation algorithms that rely on image features alone can perform poorly under certain lighting conditions, or if the object and the background have similar appearance. In parallel, known object segmentation algorithms that rely exclusively on three dimensional (3D) geometric data are derived under strong assumptions about the geometry of the scene. A promising approach to performing object segmentation is to use a combination of appearance and 3D features. In this paper, an object segmentation algorithm is presented that combines multiple appearance and geometric cues. The segmentation is formulated as a binary labeling problem. The Conditional Random Fields (CRF) framework is used to model the conditional probability of the labeling given the appearance and geometric data. The maximum a posteriori estimation of the labeling is obtained by minimizing the energy function corresponding to the CRF using graph cuts. A simple and efficient method for initializing the proposed algorithm is also presented. Experimental results have demonstrated the effectiveness of the proposed algorithm.     

QoSPlan: A Measurement Based Quality of Service aware Network Planning Framework

In this article we present QoSPlan—a measurement based framework for preparing information relevant to Quality of Service (QoS)-aware IP network planning, which aims at reducing a core operational expenditure for the network operator. QoSPlan is designed to reduce the cost of deployment and maintenance of network monitoring systems. The process involves analysis of pre-existing accounting data to estimate a network-wide traffic matrix. Part of this estimation process relates to the generalization of QoS-related effective bandwidth coefficients taken from traffic analyzed on the network. We offer recommendations on how to appropriately realize QoSPlan to maximize its accuracy and effectiveness when applied to different network traffic scenarios. This is achieved through a thorough sensitivity analysis of the methods proposed using real traffic scenarios and indicative network topologies. We also provide an economic analysis of the deployment and maintenance costs associated with QoSPlan in comparison to a direct measurement approach, demonstrating cost savings of up to 60 % given different topology sizes.     

Super-EGO: fast multi-dimensional similarity join

Efficient processing of high-dimensional similarity joins plays an important role for a wide variety of data-driven applications. In this paper, we consider $\varepsilon $ -join variant of the problem. Given two $d$ -dimensional datasets and parameter $\varepsilon $ , the task is to find all pairs of points, one from each dataset that are within $\varepsilon $ distance from each other. We propose a new $\varepsilon $ -join algorithm, called Super-EGO, which belongs the EGO family of join algorithms. The new algorithm gains its advantage by using novel data-driven dimensionality re-ordering technique, developing a new EGO-strategy that more aggressively avoids unnecessary computation, as well as by developing a parallel version of the algorithm. We study the newly proposed Super-EGO algorithm on large real and synthetic datasets. The empirical study demonstrates significant advantage of the proposed solution over the existing state of the art techniques.     

A remark on the configurational entropy of a liquid solution with a weak tendency to association

A weak tendency to association may significantly increase the molar configurational entropy of a liquid solution. This circumstance should not be overlooked if one intends to use a positive excess entropy to describe experimental data within the framework of the CALPHAD method.     

Laser powered heating stage in a scanning electron microscope for microstructural investigations at elevated temperatures

A laser powered heating stage designed for application in high vacuum environment of a scanning electron microscope (SEM) is presented. It was developed to observe and characterize microstructural changes in crystalline materials at elevated temperatures up to 1000 degrees C. The approach utilizes the power output of a commercial infrared diode laser in order to heat up specimens without interference with the electronic system of the SEM. The heating stage can be used in combination with any standard characterization technique applicable for SEMs--electron backscatter diffraction, orientation contrast imaging, x-ray energy dispersive spectrometry, etc. The results of test measurements are presented.     

A consistent muscle activation strategy underlies crawling and swimming in Caenorhabditis elegans

Although undulatory swimming is observed in many organisms, the neuromuscular basis for undulatory movement patterns is not well understood. To better understand the basis for the generation of these movement patterns, we studied muscle activity in the nematode Caenorhabditis elegans. Caenorhabditis elegans exhibits a range of locomotion patterns: in low viscosity fluids the undulation has a wavelength longer than the body and propagates rapidly, while in high viscosity fluids or on agar media the undulatory waves are shorter and slower. Theoretical treatment of observed behaviour has suggested a large change in force–posture relationships at different viscosities, but analysis of bend propagation suggests that short-range proprioceptive feedback is used to control and generate body bends. How muscles could be activated in a way consistent with both these results is unclear. We therefore combined automated worm tracking with calcium imaging to determine muscle activation strategy in a variety of external substrates. Remarkably, we observed that across locomotion patterns spanning a threefold change in wavelength, peak muscle activation occurs approximately 45° (1/8th of a cycle) ahead of peak midline curvature. Although the location of peak force is predicted to vary widely, the activation pattern is consistent with required force in a model incorporating putative length- and velocity-dependence of muscle strength. Furthermore, a linear combination of local curvature and velocity can match the pattern of activation. This suggests that proprioception can enable the worm to swim effectively while working within the limitations of muscle biomechanics and neural control.     

Report: 10th annual workshop,membrane discussions 2000

The 10th Annual Workshop 'Membrane Discussions 2000' was held during July 2000 in Kostroma, Russia. The workshop was organised by research and development company TEKO, together with the Association ASPECT of the Ministry of the Atomic Industry of the Russian Federation. This brief review of the event summarises key presentations, and looks at some of the developing technologies which were discussed.     

On the Relation of Microstructure and Texture Evolution in an Austenitic Fe-28Mn-0.28C TWIP Steel During Cold Rolling

In the present study, microstructure and texture evolution in an austenitic Fe-28 wt pct Mn-0.28 wt pct C TWIP steel in the range between 10 and 80 pct reduction by cold rolling were systematically analyzed. The formation of the observed microstructural features occurred in three different stages: I (10 to 20 pct)—mainly slip lines, grain elongation, and formation of few twin-matrix lamellae; II (30 to 50 pct)—severe increase of the volume fraction of twins, alignment of twins with the rolling plane, and formation of microshear bands; and III (60 to 80 pct)—further alignment of twins, evolution of a herring bone structure, and macroshear bands. In contrast to most f.c.c. metals, the transition from Copper- to Brass-type texture occurred at low strain levels (30 pct). This behavior is attributed to the early formation of deformation twins in the material and can be related to the SFE of this high manganese steel. At higher reduction levels, microscopic (≥40 pct) and macroscopic shear band formation (≥60 pct) contributed to the increase of randomly oriented grains, mainly at the expense of the Brass component. Furthermore, the formation of the Goss component and of the 〈111〉//ND fiber (γ) is attributed to severe twin formation.     

Thermodynamic calculation of phase equilibria of the Bi-Sn-Zn system

A thermodynamic assessment of the Bi-Sn-Zn ternary system was carried out by considering the experimental data including the phase equilibria and thermodynamic properties on the basis of the CALPHAD method. A set of optimized thermodynamic parameters has been obtained, which leads to a very good fit between calculation and experiments. In particular, the thermodynamic calculations in the Sn-rich portion are presented in view of the recent progress in Pb-free solder alloys.