Modelos para el análisis de pérdidas de AFR en sistema paralelo de mejor esfuerzo

En este trabajo se presentan dos modelos de aproximación para la determinación de la relación de pérdidas de cuadros de la técnica de paralelización Alternate Frame Rendering en un sistema de renderización de mejor esfuerzo. El primero de los modelos considera que la velocidad de cuadros por nodo es constante en el tiempo, mientras que en el segundo, la velocidad de cuadros por nodo varía en el tiempo pero, la velocidad de cuadros promedio es constante entre todos los nodos. Finalmente, se presentan resultados de desempeño teórico simulados hasta 512 nodos y se concluye que, para ambos modelos, el sistema posee una buen desempeño para menos de 16 nodos.Sociedad Argentina de Informática e Investigación Operativ

Modelos para el análisis de pérdidas de AFR en sistema paralelo de mejor esfuerzo

En este trabajo se presentan dos modelos de aproximación para la determinación de la relación de pérdidas de cuadros de la técnica de paralelización Alternate Frame Rendering en un sistema de renderización de mejor esfuerzo. El primero de los modelos considera que la velocidad de cuadros por nodo es constante en el tiempo, mientras que en el segundo, la velocidad de cuadros por nodo varía en el tiempo pero, la velocidad de cuadros promedio es constante entre todos los nodos. Finalmente, se presentan resultados de desempeño teórico simulados hasta 512 nodos y se concluye que, para ambos modelos, el sistema posee una buen desempeño para menos de 16 nodos.Sociedad Argentina de Informática e Investigación Operativ

Modelos para el análisis de pérdidas de AFR en sistema paralelo de mejor esfuerzo

En este trabajo se presentan dos modelos de aproximación para la determinación de la relación de pérdidas de cuadros de la técnica de paralelización Alternate Frame Rendering en un sistema de renderización de mejor esfuerzo. El primero de los modelos considera que la velocidad de cuadros por nodo es constante en el tiempo, mientras que en el segundo, la velocidad de cuadros por nodo varía en el tiempo pero, la velocidad de cuadros promedio es constante entre todos los nodos. Finalmente, se presentan resultados de desempeño teórico simulados hasta 512 nodos y se concluye que, para ambos modelos, el sistema posee una buen desempeño para menos de 16 nodos.Sociedad Argentina de Informática e Investigación Operativ

Crew aiding and automation: A system concept for terminal area operations, and guidelines for automation design

This research and development program comprised two efforts: the development of guidelines for the design of automated systems, with particular emphasis on automation design that takes advantage of contextual information, and the concept-level design of a crew aiding system, the Terminal Area Navigation Decision Aiding Mediator (TANDAM). This concept outlines a system capable of organizing navigation and communication information and assisting the crew in executing the operations required in descent and approach. In service of this endeavor, problem definition activities were conducted that identified terminal area navigation and operational familiarization exercises addressing the terminal area navigation problem. Both airborne and ground-based (ATC) elements of aircraft control were extensively researched. The TANDAM system concept was then specified, and the crew interface and associated systems described. Additionally, three descent and approach scenarios were devised in order to illustrate the principal functions of the TANDAM system concept in relation to the crew, the aircraft, and ATC. A plan for the evaluation of the TANDAM system was established. The guidelines were developed based on reviews of relevant literature, and on experience gained in the design effort

Modelling and detection of faults in axial-flux permanent magnet machines

The development of various topologies and configurations of axial-flux permanent magnet machine has spurred its use for electromechanical energy conversion in several applications. As it becomes increasingly deployed, effective condition monitoring built on reliable and accurate fault detection techniques is needed to ensure its engineering integrity. Unlike induction machine which has been rigorously investigated for faults, axial-flux permanent magnet machine has not. Thus in this thesis, axial-flux permanent magnet machine is investigated under faulty conditions. Common faults associated with it namely; static eccentricity and interturn short circuit are modelled, and detection techniques are established. The modelling forms a basis for; developing a platform for precise fault replication on a developed experimental test-rig, predicting and analysing fault signatures using both finite element analysis and experimental analysis. In the detection, the motor current signature analysis, vibration analysis and electrical impedance spectroscopy are applied. Attention is paid to fault-feature extraction and fault discrimination. Using both frequency and time-frequency techniques, features are tracked in the line current under steady-state and transient conditions respectively. Results obtained provide rich information on the pattern of fault harmonics. Parametric spectral estimation is also explored as an alternative to the Fourier transform in the steady-state analysis of faulty conditions. It is found to be as effective as the Fourier transform and more amenable to short signal-measurement duration. Vibration analysis is applied in the detection of eccentricities; its efficacy in fault detection is hinged on proper determination of vibratory frequencies and quantification of corresponding tones. This is achieved using analytical formulations and signal processing techniques. Furthermore, the developed fault model is used to assess the influence of cogging torque minimization techniques and rotor topologies in axial-flux permanent magnet machine on current signal in the presence of static eccentricity. The double-sided topology is found to be tolerant to the presence of static eccentricity unlike the single-sided topology due to the opposing effect of the resulting asymmetrical properties of the airgap. The cogging torque minimization techniques do not impair on the established fault detection technique in the single-sided topology. By applying electrical broadband impedance spectroscopy, interturn faults are diagnosed; a high frequency winding model is developed to analyse the impedance-frequency response obtained

Building Thermal Envelope

This book results from a Special Issue published in Energies, entitled “Building Thermal Envelope"". Its intent is to identify emerging research areas within the field of building thermal envelope solutions and contribute to the increased use of more energy-efficient solutions in new and refurbished buildings. Its contents are organized in the following sections: Building envelope materials and systems envisaging indoor comfort and energy efficiency; Building thermal and energy modelling and simulation; Lab test procedures and methods of field measurement to assess the performance of materials and building solutions; Smart materials and renewable energy in building envelope; Adaptive and intelligent building envelope; and Integrated building envelope technologies for high performance buildings and cities

[Activity of Institute for Computer Applications in Science and Engineering]

This report summarizes research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, fluid mechanics, and computer science

Numerical Simulation of an Open Channel Ultraviolet Waste-water Disinfection Reactor

The disinfection characteristics of an open channel ultra-violet (UV) wastewater disinfection reactor are investigated using a computational fluid dynamics (CFD) model. The model is based on the volume of fluid method to capture the water-air interface, the Lagrangian particle tracking method to determine the microbial particle trajectory and the discrete ordinate model to calculate the UV intensity field. The numerical predictions are compared with the available experimental data to validate the CFD model. A parametric study is performed to understand the effects of different parameters on the disinfection performance of the reactor. The hydraulic behaviour and the additive nature of disinfection for an open channel reactor with two lamp banks placed in series using different geometric configurations between the two lamp banks are also investigated. A scaling down methodology for the open channel reactor is developed and implemented in the CFD model to understand its applicability

The integration of CFD and VR methods to assist auxiliary ventilation practice

The current trend towards the adoption of retreat longwall mining methods and the associated rapid development of the access drivages has exacerbated the environmental conditions experienced within these workings. The combined use of roof bolt and continuous miner systems has improved the face advance rate within rapid development drivages. In order to maintain adequate dust and gas control it is essential that the auxiliary ventilation and monitoring systems are correctly installed and maintained. The causes of many potential environmental hazards experienced within auxiliary ventilated rapid development drivages, are often attributed to a failure by the workforce and supervisory officials to maintain the correct installation, maintenance and operational standards of the ventilation and mining systems. The potential ventilation hazards encountered may include: the failure to deliver the required fresh air quantity and velocity to rapidly dilute and disperse methane gas liberated in the vicinity of the cutting face, or the failure to maintain sufficient exhaust air quantity in the vicinity of the cut to adequately capture dust produced on cutting and loading of the extracted mineral. Results of recent research studies have demonstrated that validated Computational Fluid Dynamics (CFD) simulation models can adequately replicate examples of good and bad ventilation. CFD models may be constructed and solved to examine the relative ventilation benefits produced by alternative mining and auxiliary ventilation configurations. These models enable the practitioner to predict and visualise the velocity, pressure and contaminant fields within an auxiliary ventilated drivage. This research project has developed a prototype educational aid, which animates and visualises these airflow and pollutant dispersion patterns within a Virtual Reality (VR) model. By introducing a pollutant such as methane into the CFD models, the VR simulation highlights regions of potential methane concentration build-up to the trainee. The application also allows the user to select/investigate the environmental consequences of enacting a number of remedial actions