The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Numerical reproducibility failures rise in parallel computation because of the non-associativity of floating-point summation. Optimizations on massively parallel systems dynamically modify the floating-point operation order. Hence, numerical results may change from one run to another. We propose to ensure reproducibility by extending as far as possible the IEEE-754 correct rounding property to larger...
The design of high quality electron generators is important for a variety of applications including materials processing systems (including welding, cutting and additive manufacture), X-ray tubes for medical, scientific and industrial applications, microscopy, and lithography for integrated circuit manufacture. The many variants of electron gun required, and the increasing demands for highly optimised...
In many spectral estimation and array processing problems, the process of finding estimates of model parameters often involves the optimisation of a cost function containing multiple peaks and dips. Such non-convex problems are hard to solve using traditional optimisation algorithms developed for convex problems, and computationally intensive grid searches are therefore often used instead. In this...
One polygeneration node is an energy system where the user demands are met by different generation sources, possibly including renewable energy inputs and energy storages. User demands can involve one single energy vector like electricity, heating, cooling etc. or can be a combination of all of them at the same time. The management strategy of these systems is not univocal since different mix of production...
Recently, the railway sector is required to improve energy efficiency. Since no additional hardware investment is required, the authors are focused on the optimisation of the train timetable for less energy consumption. Train timetable contains the slack time for each interstation for robustness against delay. Although energy consumption can be reduced by the slack time, the slack time distribution...
With rising concerns on energy and environment, the energy-efficient operation techniques in railway systems are paid more attention in recent years. The metro-transit system has some distinguishing features like short headway and a high number of stations with short interstation distance, which makes effectively using regenerative energy becoming more significant in the energy-saving study. This...
Deep neural networks are more accurate, but require more computational power in the learning process. Moreover, it is an iterative process. The goal of the research is to investigate efficiency of solving this problem on MIC architecture without changing baseline algorithm. Well-known code vectorization and parallelization methods are used to increase the effectiveness of the program on MIC architecture...
AC magnetic flux density meters usually integrate a high pass filter with a very low cut-off frequency (1 Hz–30 Hz) aiming at reducing the effect of slow oscillations. This can distort the actual time domain behaviour of induction waveforms detectable close to industrial or medical devices, even causing artefact high amplitude oscillations. This paper proposes a procedure to identify the filter parameters...
An unconstrained optimization technique is presented for the phase-only synthesis of omnidirectional array patterns with multiple null regions from a circular array.
The popularity of Wi-Fi-enabled devices alongside the growing demand for non-licensed spectrum, has made the Wi-Fi networks exceedingly congested. This endangers the efficiency of Wi-Fi and negatively affect the users' experience. The problem is especially pressing in dense areas (e.g. shopping centers) where Wi-Fi channel assignment is more likely to be uncoordinated and the working environment of...
An increasing awareness of energy efficiency has led to the development of several improved converter topologies, semiconductor devices and control schemes for distributed energy resources, and, particularly, for microgrids. Recent advances in energy management systems (EMS) for microgrids have improved upon existing methods in several aspects, including prediction of power generated by photovoltaics...
We have previously presented Intent, a medium access control scheme for WLANs based on cooperative, distributed, non-binding frame scheduling. The main idea behind Intent is “intention sharing”—a mechanism that allows a node to be aware of transmissions previously scheduled by its neighbors. We now extend this scheme to networks with hidden nodes. We give a formulation of the scheduling problem and...
With spreading of renewable energy in energy mix of national grids, the issue of high capacity and efficient energy storage is becoming very critical. A comprehensive model of South African power grid developed at the University of Pretoria is presented in this work. The model contains all notable power generators in the country. Mixed integer non-linear optimisation techniques are employed for unit...
The operational optimization of large hydrological basins still remains a challenger issue. Large travel times of the water between upstream reservoirs and the mouth of the river, several days as horizon of optimization, very nonlinear equations, uncertainties and ecological constraints result in complex optimization problems with difficult solutions. The present work uses a new formulation, with...
This paper presents a study on the implementation of Real-Time Pricing (RTP) based Demand Side Management (DSM) of water pumping at a clean water pumping station in Northern Ireland, with the intention of minimising electricity costs and maximising the usage of electricity from wind generation. A Genetic Algorithm (GA) was used to create pumping schedules based on system constraints and electricity...
The increase in renewable energy generators introduced into the electricity grid is putting pressure on its stability and management as predictions of renewable energy sources cannot be accurate or fully controlled. This, with the additional pressure of fluctuations in demand, presents a problem more complex than the current methods of controlling electricity distribution were designed for. A global...
The current flow-based capacity calculation methodology applied in the European electricity market forces the TSOs to re-think their concepts and methodologies for network planning and investment justification. Until now, these methods have been based on methods for de-coupling of TSOs zones, based on cross-border bilateral exchanges, with reduced complexity. The main instrument of de-coupled planning...
In this paper, we present an evolutionary algorithm to place VLSI elements based on evolutionary computing with multi-chromosomes. In addition, we present possible software implementation of the algorithm based on multithread CUDA programming, and report some experimental results of the suggested algorithm implementation.
This paper presents a comparison of two logistic systems including an intermediate platform for the collection and delivery of containers with the maritime container terminals in Le Havre Port area. The first one uses a conventional operational organization of a set of rail shuttles. The second one SFM (‘Service Ferroviaire Modulaire’: modular rail service) is based on the first but with teleoperated...
Mixed-Criticality Systems are capable of accommodatingtasks of varying criticality. In this paper, these are [life, mission, and non-critical]. Tasks usually have an overestimatedexecution time to allow for the Worst Case Execution Time(WCET). When these tasks finish execution prior to their allottedexecution time due to pessimistic assumptions present in the staticanalysis of the system. The surplus...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.