Role of the inertia tensor in haptically perceiving where an object is grasped.

When an object is held and wielded, a time-invariant quantity of the wielding dynamics is the inertia tensor Iij. Examination of Iij as a function of different locations at which a cylindrical object is grasped revealed that the off-diagonal components of Iij, the products of inertia, related most systematically to grip position. In 3 experiments, Ss wielded an occluded rod held at an intermediate point along its length and reproduced, with the other hand, the felt grip position on a visible rod. In Exp 1, the wielded rods were homogeneous; in Exps 2 and 3, weights were added on either side of the grasp, with different manners of grasp contrasted in Exp 3. In all 3 experiments, perceived hand position was predicted by Iij. Discussion is focused on the role of Iij's eigenvalues in perceiving the magnitudes of objects and Iij's eigenvectors in perceiving hand–object relations (e.g., position of grasp). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

SIVR epidemic model with stochastic perturbation

We propose a stochastic disease model where vaccination is included and such that the immunity is permanent. The existence, uniqueness, and positivity of the solution and the stability of the disease-free equilibrium are studied.     

Adaptive Census Transform: A novel hardware-oriented stereovision algorithm

This paper presents a new hardware-oriented approach for the extraction of disparity maps from stereo images. The proposed method is based on the herein named Adaptive Census Transform that exploits adaptive support weights during the image transformation; the adaptively weighted sum of SADs is then used as the dissimilarity metric. Quality tests show that the proposed method reaches significantly better accuracy than alternative hardware-oriented approaches. To demonstrate the practical hardware feasibility, a specific architecture has been designed and its implementation has been carried out using a single FPGA chip. Such a VLSI implementation allows a frame rate up to 68 fps to be reached for 640 × 480 stereo images, using just 80,000 slices and 32 RAM blocks of a Virtex6 chip.     

A multi-scale template method for shape detection with bio-medical applications

In this paper we present a novel methodology based on non-parametric deformable prototype templates for reconstructing the outline of a shape from a degraded image. Our method is versatile and fast and has the potential to provide an automatic procedure for classifying pathologies. We test our approach on synthetic and real data from a variety of medical and biological applications. In these studies it is important to reconstruct accurately the shape of the object under investigation from very noisy data. Here we assume that we have some prior knowledge about the object outline represented by a prototype shape. Our procedure deforms this shape by means of non-affine transformations and the contour is reconstructed by minimizing a newly developed objective function that depends on the transformation parameters. We introduce an iterative template deformation procedure in which the scale of the deformation decreases as the algorithm proceeds. We compare our results with those from a Gaussian Mixture Model segmentation and two state-of-the-art Level Set methods. This comparison shows that the proposed procedure performs consistently well on both real and simulated data. As a by-product we develop a new filter that recovers the connectivity of a shape.

An empirical evaluation of active learning strategies for profile elicitation in a conversational recommender system

Journal of Intelligent Information Systems - Conversational Recommender Systems have received widespread attention in both research and practice. They assist people in finding relevant and...     

Investigating haptic distance-to-break using linear and nonlinear materials in a simulated minimally invasive surgery task

Accurate detection of mediated haptic information in minimally invasive surgery (MIS) is critical for applying appropriate force magnitudes onto soft tissue with the aim of minimising tissue trauma. Force perception in MIS is a dynamic process, with surgeons’ administration of force into tissue revealing information about the remote surgical site which further informs the surgeons’ haptic interactions. The relationship between applied force and material deformation rate provides biomechanical information specifying the deformation distance remaining until a tissue will fail: which is termed distance-to-break (DTB). The current study demonstrates that observers can detect DTB while deforming simulated tissues and stop before reaching the tissues’ failure points. The design of training simulators, control devices and automated robotic systems for applications outside of MIS is discussed.

Practitioner Summary: In MIS, haptic information is critical for applying appropriate forces onto soft tissue to minimise tissue trauma. Observers used force information to detect how far they could deform a virtual tissue before it would break. The design of training simulators, control devices and automated robotic systems is discussed.     

Experimental technique for reducing contact and background noise in voltage spectral density measurements

Electric noise measurements can give useful information on the conduction mechanisms and the dynamic behaviors of the charge carriers in new materials. However, it is well known that not all the electronic fluctuations are originated from the material itself, but some noise sources depend on the experimental procedures used for the measurements. In this article, an experimental technique to reduce "external" noise components, not associated with the bulk system, is presented. The proposed method is based on measurements of the voltage spectral density, using in sequence a four- and a two-probe technique. From the measurements it is possible to evaluate the contact and the background noise contributions and to recover the real spectral trace of the sample. The proposed procedure is demonstrated to be valid in spectral density measurements performed on La(0.7)Sr(0.3)MnO(3) thin films.