Search results for "reduction"
showing 10 items of 2058 documents
A new autonomous data transmission reduction method for wireless sensors networks
2018
International audience; The inherent limitation in energy resources and computational power for sensor nodes in a Wireless Sensor Network, poses the challenge of extending the lifetime of these networks. Since radio communication is the dominant energy consuming activity, most presented approaches focused on reducing the number of data transmitted to the central workstation. This can be achieved by deploying both on the workstation and the sensor node a synchronized prediction model capable of forecasting future values. Thus, enabling the sensor node to transmit only the values that surpasses a predefined error threshold. This mechanism offers a decrease in the cost of transmission energy f…
Dimension Estimation in Two-Dimensional PCA
2021
We propose an automated way of determining the optimal number of low-rank components in dimension reduction of image data. The method is based on the combination of two-dimensional principal component analysis and an augmentation estimator proposed recently in the literature. Intuitively, the main idea is to combine a scree plot with information extracted from the eigenvectors of a variation matrix. Simulation studies show that the method provides accurate estimates and a demonstration with a finger data set showcases its performance in practice. peerReviewed
Ranking of occupational health and safety risks by a multi-criteria perspective: Inclusion of human factors and application of VIKOR
2021
Nowadays, the Occupational Health and Safety (OHS) is more and more recognized as a crucial process to be properly managed and continuously improved by every organization. Primarily addressed to prevent workers’ injuries and diseases, it positively impacts on productivity, competitiveness and reputation as well as it con-tributes to cost savings in general. OHS management is grounded upon the risk assessment results, on the basis of which defining corrective measures to be taken to reduce risks to acceptable values. In this regard, the paper proposes a Multi-Criteria Decision Making (MCDM) based methodology addressed to the occupational risks prioritization. In order to overcome the shortco…
Restoration and Enhancement of Historical Stereo Photos Through Optical Flow
2021
Restoration of digital visual media acquired from repositories of historical photographic and cinematographic material is of key importance for the preservation, study and transmission of the legacy of past cultures to the coming generations. In this paper, a fully automatic approach to the digital restoration of historical stereo photographs is proposed. The approach exploits the content redundancy in stereo pairs for detecting and fixing scratches, dust, dirt spots and many other defects in the original images, as well as improving contrast and illumination. This is done by estimating the optical flow between the images, and using it to register one view onto the other both geometrically …
Numerical experiments with a parallel fast direct elliptic solver on Cray T3E
1997
A parallel fast direct O(N log N) solver is shortly described for linear systems with separable block tridiagonal matrices. A good parallel scalability of the proposed method is demonstrated on a Cray T3E parallel computer using MPI in communication. Also, the sequential performance is compared with the well-known BLKTRI-implementation of the generalized. cyclic reduction method using a single processor of Cray T3E.
Design of experiment approach applied to reducing and oxidizing tolerance of anode supported solid oxide fuel cell. Part I: Microstructure optimizati…
2011
The main drawback of Ni/YSZ anode supports for solid oxide fuel cell application is their low tolerance to reducing and oxidizing (RedOx) atmosphere changes, owing to the Ni/NiO volume variation. This work describes a structured approach based on design of experiments for optimizing the microstructure for RedOx stability enhancement. A full factorial hypercube design and the response surface methodology are applied with the variables and their variation range defined as: (1) NiO proportion (40-60 wt% of the ceramic powders), (2) pore-former proportion (0-30 wt% corresponding to 0-64 vol.%), (3) NiO particle size (0.5-8 mu m) and (4) 8YSZ particle size (0.6-9 mu m).
Endodontic re-treatment and restorative treatment of a dens invaginatus type II through new technologies
2019
Background The complex anatomy of dens invaginatus makes access cavity to root canal system difficult, which has an impact on the prognosis of these teeth. A novel technique, based on new technologies, is proposed to make access cavity conservative and guided with minimal dental structure lost. Material and Methods This case report shows the root canal retreatment and the endodontic surgery of a dens invaginatus type II in a left lateral upper incisor previously treated which was affected by a chronic apical abscess and an apical fracture. A Cone Beam Computed Tomography was performed to better diagnosis the dental anatomy. An intraoral scan was performed to get a digital 3D model. A comput…
On cone-beam computed tomography artifacts induced by titanium implants
2010
Objectives: To briefly review the mathematical background of beam-hardening artifacts in cone-beam computed tomography (CBCT)-reconstruction and to investigate geometrical properties relevant for these reconstruction errors. By means of simulated and experimental results, beam-hardening effects caused by titanium implants are evaluated. Materials and methods: The geometrical and physical properties of the acquisition process of the projections used for 3D reconstruction are investigated and their effects on the CBCT images in the presence of titanium implants are derived. Beam-hardening effects are computed for a simplified polychromatic situation (three energy subsets of 80 and 110 kV) and…
Accelerating orthodontic tooth movement: a new, minimally-invasive corticotomy technique using a 3D-printed surgical template
2015
Background A reduction in orthodontic treatment time can be attained using corticotomies. The aggressive nature of corticotomy due to the elevation of muco-periosteal flaps and to the duration of the surgery raised reluctance for its employ among patients and dental community. This study aims to provide detailed information on the design and manufacture of a 3D-printed CAD-CAM (computer-aided design and computer-aided manufacturing) surgical guide which can aid the clinician in achieving a minimally-invasive, flapless corticotomy. Material and Methods An impression of dental arches was created; the models were digitally-acquired using a 3D scanner and saved as STereoLithography ( STL ) file…
Consensus Document on Intermittent Claudication from the Central European Vascular Forum (C.E.V.F.)-3rd revision (2013) with the sharing of the Medit…
2014
This paper is the review of the Consensus Document on Intermittent Claudication of the Central European Vascular Forum (CEVF), published in 2008, and and shared with the North Africa and Middle East Chapter of International Union of Angiology and the Mediterranean League of Angiology and Vascular Surgery. The Document presents suggestions for general practitioners and vascular specialists for more precise and appropriate management of PAD, particularly of intermittent claudication, and underlines the investigations that should be required by GPs and what the GP should expect from the vascular specialist (angiologist, vascular surgeon). The idea of the Faculty is to produce a short document,…