Learning Boundary Edges for 3D‐Mesh Segmentation

This paper presents a 3D‐mesh segmentation algorithm based on a learning approach. A large database of manually segmented 3D‐meshes is used to learn a boundary edge function. The function is learned using a classifier which automatically selects from a pool of geometric features the most relevant ones to detect candidate boundary edges. We propose a processing pipeline that produces smooth closed boundaries using this edge function. This pipeline successively selects a set of candidate boundary contours, closes them and optimizes them using a snake movement. Our algorithm was evaluated quantitatively using two different segmentation benchmarks and was shown to outperform most recent algorithms from the state‐of‐the‐art.     

The Color Monogenic Signal: Application to Color Edge Detection and Color Optical Flow

The aim of this paper is to define an extension of the analytic signal for a color image. We generalize the construction of the so-called monogenic signal to mappings with values in the vectorial part of the Clifford algebra ℝ_5,0. Solving a Dirac equation in this context leads to a multiscale signal (relatively to the Poisson scale-space) which contains both structure and color information. The color monogenic signal can be used in a wide range of applications. Two examples are detailed: the first one concerns a multiscale geometric segmentation with respect to a given color; the second one is devoted to the extraction of the optical flow from moving objects of a given color.     

Slippage of binary fluid mixtures in a nanopore

This work focuses on the slip phenomenon at the fluid–solid interface accompanying Poiseuille flow of simple binary miscible fluids in a slit nanopore. To explore such flows, molecular dynamics simulations are used on Lennard–Jones binary mixtures composed of species of varying affinities with the walls. The results have shown that the apparent slip magnitude at the fluid–solid interface depends largely on the species that is dominant in contact with the walls. In addition, it has been shown that the velocity profiles of each species (of different “wettability”) does not superpose with the velocity profile of the mixture and such a result points out the limitations of the classical approaches based on a single momentum conservation equation to deal with mixtures flow in nanochannels.     

Preparation of Activated Carbon from Cashew Nut Shells for Water Purification

Russian Journal of Non-Ferrous Metals - The application of the agricultural waste of cashew nut shells (CNSs) from the Ivory Coast is proposed for the production of activated carbon (AC) used in...     

Organization of digital resources as an original facet for exploring the quiescent information capital of a community

Knowledge workers organize the documents they need for daily task achievement in their personal information spaces (PISs). For a community, people’s PISs constitute in-house value-added resources. Paradoxically, this information source is poorly exploited, as people tend to use external sources (e.g., the Web), although this is probably poorly appropriate in corporate context. This article tackles such information access issues in the common context. Our contribution consists in a faceted visual interface to explore various facets (points of view) of the information of a community, which remains quiescent otherwise. Besides common facets only based on information contents, we propose a new facet relying on the way users in a community manage and organize information. As a result, our approach exploits knowledge workers’ efforts devoted to PIS management, turning them to profit for all, by fostering mutual benefit between stakeholders. The proposed facet relies on an original organization-based similarity measure that we define and experiment.     

Augmented reality supporting user-centric building information management

The rapid development of geo-referenced information changed the way on how we access and interlink data. Smartphones as enabling devices for information access are main driving factor. Thus, the hash key to information is the actual position registered via camera and sensory of the mobile device. A rising technology in this context is Augmented Reality (AR) as its fuses the real world captured with the smartphone camera with geo-referenced data. The technological building blocks analyse the intrinsic sensor data (camera, GPS, inertial) to derive a detailed pose of the smartphone aiming to align geo-referenced information to our real environment. In particular, this is interesting to applications where 3D models are used in planning and organization processes as, e.g., facility management. Here, Building Information Models (BIM) were established in order to hold “as built” information, but also to manage the vast amount of additional information coming with the design, such as building components, properties, maintenance logs, documentation, etc. One challenge is to enable stakeholders involved in the overall building lifecycle to get mobile access to the management system within on-site inspections and to automatise feedback of newly generated information into the BIM. This paper describes a new AR framework that offers on-site access to BIM information and user centric annotation mechanism.     

Three‐Dimensional Constrained Tracking Control Via Exact Differentiation Estimator of a Quadrotor Helicopter

In this paper, a constructive method is presented to design a three dimensional trajectory tracking controller that forces a quadrotor helicopter to track a bounded and sufficiently smooth reference trajectory asymptotically in the presence of constant force disturbances. The quadrotor helicopter under consideration has fewer independent thrusters than degrees of freedom to be controlled. Motivated by the vehicle's steering practices, the roll and pitch angles are regarded as virtual controls along with four control forces to fulfill the task of position and yaw angle reference tracking. To prevent position constraint violation, the barrier Lyapunov function (BLF) is employed in the vectorial backstepping procedure to guarantee that the position and attitude constraints are not violated. The backstepping procedure employs an exact and robust sliding mode differentiator of order two to facilitate the implementation of the attitude command signal without calculating the virtual control signal derivative analytically.     

Firm strategic profile and IT outsourcing

IT outsourcing research has often been at the transaction level, focusing on the role of the characteristics of the IT activities as the antecedents of outsourcing decisions. The present study extends past research efforts examining the relationships between organizational level variables—in particular the business strategy—and the decision to outsource. Results show that prospectors and analyzers are more aggressive in their use of outsourcing for IT operations. However, no differences between the behaviour of the different strategic groups were found for maintenance activities, suggesting that these activities are too far from the core of the organization to be influenced by strategic profile.