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.
The South African industrial sector is under significant financial pressure and need to reduce production costs to remain competitive in the global and local market. Some steel plants use reheating furnaces to reheat materials before hot rolling. These furnaces use industrial fuel gases as an energy source. Process by-product and purchased gases can be used as fuel. Inefficiencies in gas distribution...
In tourism industry, a challenge is how to handle emergency situations during a journey. Although most of the tourism travel agencies focus on generating travel plans, an important part that has been ignored is to provide a creative emergency travel plan when a user meets an unforeseen situation during the journey. Thus, in order to address problems like this, the study to build a system that can...
Areas missing wide electricity grid deployment require set-up of local and small scale grids (nano-grids) covering individual or group of houses. Such systems require a performance/cost optimisation. A simulation has been developed to evaluate management algorithms. A 15 % optimisation through the use of simple predictive algorithms is demonstrated.
The problem of efficient resource management in large cloud data centres is well recognised in the cloud management community. With the rising demand for cloud services and expansion of the size and distribution of data centres, the repercussions of not taking into account all parameters of interest while allocating resources are becoming significant. Hence, one of the major issues today is how to...
Modelling and simulation assist in decision support or planning activities by allowing efficient exploration of multiple scenarios in a situation where testing in a real setting is impractical. This exploration is often done by varying numerical parameters in the model such as physical dimensions or speed in order to find the optimal configuration. However, for certain problems, in order to find optimal...
Most games have, or can be generalised to have, a number of parameters that may be varied in order to provide instances of games that lead to very different player experiences. The space of possible parameter settings can be seen as a search space, and we can therefore use a Random Mutation Hill Climbing algorithm or other search methods to find the parameter settings that induce the best games. One...
Hybrid digital-to-analog (D-A) precoding is a promising technology to reduce the number of radio frequency (RF) chains in a millimetre-wave (mm-Wave) multiple-input multiple-output (MIMO) system. To reap the full scale benefits of the hybrid D-A precoding, in this paper, two algorithms are proposed to maximise the capacity of the hybrid D-A mm-Wave MIMO system. The first algorithm is based on the...
In this paper, a multi-objective optimisation procedure based on the non-sorted genetic algorithm-II (NSGA-II) for the design of a buried PM wind generators with variable-flux is presented. A comparative analysis is carried out for optimised 13 kW, 100 kW and 1 MW buried-PM variable-flux synchronous generators (VFSG) with PMs buried deep in the rotor cores and additional rotor field coils. A design...
The design of an aperiodic frequency selective surface (FSS) for compact quasi-optical networks is presented in this paper. Using a newly developed Physical Optics (PO) method in conjunction with a direct optimisation approach where all elements are simultaneously optimised, an FSS with an aperiodic element layout operating in several discrete bands over the frequency range 23–230 GHz has been designed...
In this paper, we propose to present the modelling of multivariable Autoregressive with exogenous input (ARX) model by using Laguerre functions. The optimal approximation of the resulting model, entitled MIMO ARX Laguerre model, is ensured when the poles characterizing each Laguerre bases are optimal. An evolutionary method is proposed for the optimization of the Laguerre poles from input/output measurements...
In order to evaluate complex and computationally expensive experiments, data-driven meta-models are used to replace costly experiments and approximate the real experiments' outcome. In this study, an evaluation framework is proposed for measuring the performance of these models. Explored is how the performance is related to the difference between the benchmark optimum and the model optimum, and a...
We revisit the problem of traffic signal control in urban traffic networks. Recent work in the literature has studied the use of scheduling algorithms from communication networks to traffic signal control with the aim of maximising the network throughput. However, these algorithms are unable to capture some of the network characteristics such as protocol constraints or penalties on the control actions,...
Nowadays the amount of electrical power generated on-board ships is drastically increased, especially for the All Electric Ships (AES) where all the energy needed is supplied by the electrical power system. In this context, the traditional methods to calculate the power demand and select the size of the generation system have become inadequate, since they are based on very dated assumptions. Aim of...
Additive-layered manufacturing has gained attentionin recent years as it has many advantages over conventionalinjection moulding methods. The optimization of printing trajectoriescan be formulated as a travelling salesman problem (TSP) and solved accordingly. However, computational complexities ofordinary TSP solvers can increase tremendously with the scaleof the problem, which make them impractical...
Conservation voltage reduction (CVR), the theory that reducing distribution feeder voltages will result in a reduction in demand, has recently been reintroduced with the aim of improving overall energy efficiency. Although CVR is a simple and cost-effective scheme, reducing voltages may not always be the most beneficial decision in terms of reducing demand. In fact, for certain types of load, reducing...
Today, Apache Cassandra, an highly scalable and available NoSql datastore, is largely used by enterprises of each size and for application areas that range from entertainment to big data analytics. Managed Cassandra service providers are emerging to hide the complexity of the installation, fine tuning and operation of Cassandra datacenters. As for all complex services, human assisted management of...
In the study the possibilities of using personal computers equipped with multi-core processors for optimisation calculations of complex technical objects were analysed. Desktops and portable computers, such as laptops, were compared. The exemplary object which was subject to the optimisation process was a three-phase, unshielded busduct in constant insulation. A genetic algorithm method was used for...
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...
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...
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.