3,506 research outputs found
A Hybrid Deep Learning Approach for Texture Analysis
Texture classification is a problem that has various applications such as
remote sensing and forest species recognition. Solutions tend to be custom fit
to the dataset used but fails to generalize. The Convolutional Neural Network
(CNN) in combination with Support Vector Machine (SVM) form a robust selection
between powerful invariant feature extractor and accurate classifier. The
fusion of experts provides stability in classification rates among different
datasets
Experimental Investigation of Chicken Manure Pyrolysis and Gasification
The dependency on renewable resources of energy in power production is a necessary step that mankind has to take if we want our advances in life and technology to resume. In a century or two, fossil fuels will be depleted, and if we do not start to take action, Energy will be the most expensive and rare item on our planet. Biomass is one of the sources of renewable energy with an advantage of being the closest in characteristics to fossil fuels. The evolved gases are similar to fossil fuel gases which makes itthe easiest source to switch to, with the least infrastructure required. In this doctoral thesis, the experimental study of the Pyrolysis and gasification of chicken manure is presented. Both evolved gas analysis (EGA) and thermo-gravimetric analysis (TGA) have been investigated in details using different gasifying agents. In EGA, the concentrations and the mass flow rates of different evolved gases were presented and the mass flow rates were used to calculate the energy and carbon conversion efficiencies. Different gases including (N2, air, CO2, steam, and mixtures) were used as the gasifying agents, and the effect of temperature 600-1000oC was tested. The effect of adding oxygen to steam gasification at 900oC was studied and presented in details. In TGA, the degradation and rate of degradation of the mass was analyzed with different gases (N2, air, and CO2) for various heating rates (5-40oC/min.) using the extent of reaction, α. The order of reaction model was then used to find the chemical kinetic parameters for the different gases
Linear-time Online Action Detection From 3D Skeletal Data Using Bags of Gesturelets
Sliding window is one direct way to extend a successful recognition system to
handle the more challenging detection problem. While action recognition decides
only whether or not an action is present in a pre-segmented video sequence,
action detection identifies the time interval where the action occurred in an
unsegmented video stream. Sliding window approaches for action detection can
however be slow as they maximize a classifier score over all possible
sub-intervals. Even though new schemes utilize dynamic programming to speed up
the search for the optimal sub-interval, they require offline processing on the
whole video sequence. In this paper, we propose a novel approach for online
action detection based on 3D skeleton sequences extracted from depth data. It
identifies the sub-interval with the maximum classifier score in linear time.
Furthermore, it is invariant to temporal scale variations and is suitable for
real-time applications with low latency
Multiuser Switched Diversity Scheduling Schemes
Multiuser switched-diversity scheduling schemes were recently proposed in
order to overcome the heavy feedback requirements of conventional opportunistic
scheduling schemes by applying a threshold-based, distributed, and ordered
scheduling mechanism. The main idea behind these schemes is that slight
reduction in the prospected multiuser diversity gains is an acceptable
trade-off for great savings in terms of required channel-state-information
feedback messages. In this work, we characterize the achievable rate region of
multiuser switched diversity systems and compare it with the rate region of
full feedback multiuser diversity systems. We propose also a novel proportional
fair multiuser switched-based scheduling scheme and we demonstrate that it can
be optimized using a practical and distributed method to obtain the feedback
thresholds. We finally demonstrate by numerical examples that
switched-diversity scheduling schemes operate within 0.3 bits/sec/Hz from the
ultimate network capacity of full feedback systems in Rayleigh fading
conditions.Comment: Accepted at IEEE Transactions on Communications, to appear 2012,
funded by NPRP grant 08-577-2-241 from QNR
Integrated Real-Virtuality System and Environments for Advanced Control System Developers and Machines Builders
The pace of technological change is increasing and sophisticated customer driven markets are forcing rapid machine evolution, increasing complexity and quality, and faster response. To survive and thrive in these markets, machine builders/suppliers require absolute customer and market orientation, focusing on .. rapid provision of solutions rather than products. Their production systems will need to accommodate unpredictable changes while maintaining financial and operational efficiency with short lead and delivery times. Real-Virtuality (R-V) systems are an innovative environment to address these requirements by facilitating enhanced support in machine system design utilising integrated real-virtual environments centred on concurrent machine system development and realization. This environment supports not only machine system design but also the development of the' control system at the same time. Utilising the Real-Virtual Mapping Environment (RVMI;:), 3-D simulation machine models can perform actual machine operations in real-time when coupled with the real machine controller. This provides a more understandable, reliable and transparent machine function and performance. The research study explores different types of controller verification methods and proposes a new method which employs the use of a control signal emulator. The research study has fomulated a novel technique for emulating quadrature encoder signals to provide virtual closed loop control of servomotors. The deployment of a control signal emulator technique makes the system unique and removes its dependency on specific hardware. Enabling the real-time data from the signal emulation environment eases the task of realising a real-time machine simulator. To evaluate the proposed architecture, three case studies were performed. The results have shown that it is possible to create verified and validated machine control programs with no modification needed when applied to the real machine. The migration from the virtual to the real world is totally seamless. The result from the ????study show that the virtual machine is able to operate and respond as a real machine in real-time. This opens up the unexplored potential of integrated 3-D virtual technology. The real-time 3-D simulation virtual machine will enable commissioning and training to be conducted '!-t an earlier stage in the design process (without having to wait for the real machine to be built). Furthermore, various test scenarios can also be developed and tested on the system which helps to provide a better lofriderstanding of the machine behaviours and responses. This research study has made an original contribution in the field of machine system development. It has contributed a novel approach of using emulated control signals to provide machine control programmers with a platform to test their application programs at machine level which involves both discrete digital signals and continuous signals. The real-time virtual environment extends the application domain for the use of simulation. The architecture proposed is generic; to be exact it is not constrained to a specific industrial control system or to a specific simulation vendor
Dabiq: A study of the usage of terrorist-produced publications in framing and selective moral disengagement
Dabiq, the official English language publication of ISIS, the Islamic State in Iraq and Syria, has been widely circulated online, and has gained a relatively large audience. The study discusses the ways in which the Islamic State of Iraq and Syria (ISIS) uses their official publication, Dabiq, to promote its objectives and to spread terror. In this study, a content analysis is conducted to examine terrorist rhetoric in the magazine and its mediation for the sake of fulfilling the group’s objectives. The study uses two main theories: the theory of framing analyzing how ISIS frames itself, its supporters and its opponents, and the theory of selective moral disengagement, analyzing the mechanisms ISIS uses through Dabiq to morally disengage their soldiers and supporters, thus allowing them to commit more violent acts without exercising their moral agency or feeling empathetic towards their victims. The content analysis was conducted on the whole Dabiq population (15 issues, containing 206 articles). The findings show that ISIS attempts to frame itself as a caliphate and a state, and a gateway to heaven, and its fighters and supporters as moral agents, and fighters for God, as opposed to the framing of their opponents and victims, which were framed as enemies of God. The interesting finding was that all supporters and fighters of ISIS are very strategically framed as part of the in-group, while all opponents and victims are framed as part of the out-group. On the other hand, when analyzing the rhetoric of the magazine from the perspective of the theory of selective moral disengagement, the findings suggest that all 7 mechanisms of moral disengagement are very significantly present in the rhetoric of the magazine, with the most used mechanism in the magazine, moral justification, being present in 97% of the total population of the magazine, and least mechanism used, dehumanization of victims, being present in 41% of the total population of the magazine. Through the study, it was found that ISIS attempts to assemble a united political identity for itself and its followers by means of framing the in-group and out-group, and morally disengaging its in-group to keep it loyal, supportive and active towards achieving its cause and purpose, and to have it enforce its attitudes of rejection and vicious behavior towards the out-group
Performance analysis of modified asymmetrically-clipped optical orthogonal frequency-division multiplexing systems
A modification to the Asymmetrically-Clipped Optical Orthogonal Frequency-Division Multiplexing (ACO-OFDM) technique is proposed through unipolar encoding. A performance analysis of the Bit Error Rate (BER) is developed and Monte Carlo simulations are carried out to verify the analysis. Results are compared to that of the corresponding ACO-OFDM system under the same bit energy and transmission rate; an improvement of 1 dB is obtained at a BER of 10-4. In addition, the performance of the proposed system in the presence of atmospheric turbulence is investigated using single-input multiple-output (SIMO) configuration and its performance under that environment is compared to that of ACO-OFDM. Energy improvements of 4 dB and 2.2 dB are obtained at a BER of 10-4 for SIMO systems of 1 and 2 photodetectors at the receiver for the case of strong turbulence, respectively
Modèle elliptique pour la section de fil. Partie 2 : la prédiction et l’ajustage d’un modèle elliptique pour des filages de coton du rotor (OE)
Un parámetro importante de la tecnología textil es la geometría de la estructura del hilo. Este parámetro se ve afectado por el de sistema de hilatura utilizado. En el proceso de hilatura se puede modificar el diámetro de la sección de hilado y la deformación de su superficie. En el trabajo anterior (parte 1) abordamos un sistema nuevo y las ecuaciones para calcular los diámetros de la sección elíptica del hilado de anillo de algodón. En este trabajo adaptaremos, con algunas modificaciones, estas ecuaciones para que sean más adecuados para su aplicación en los hilos del rotor OE. A partir de los resultados obtenidos podemos decir que, los diámetros mayor y menor (D, d) de los hilados OE son mayores que en los hilados de anillo RS, por lo tanto, las constantes en las ecuaciones cambiarán; el ajuste fue muy cercano a uno y la excentricidad fue muy cercana a 0,5. Los resultados estimados con este modelo respecto a los valores reales presentan una correlación muy elevada.An important branch of textile technology is the geometry of yarn structure where it’s changes with changing the spinning system; this changing may be effect on the yarn cross-section diameters and deformation of the yarn surface. In the earlier work (part 1) we approached a new system and equations for calculation the elliptical ring spun cotton yarn cross-section diameters. In this work a modification of these equations to be more suitable for application it on the open end yarns. From the results the major and minor diameters (D, d) of the open end OE yarn cross-section increased up to the ring spun yarns RS, therefore the constants in the equations was changed; The fitting was adjacent from one and the eccentricity was nearest of 0.5. Simulation and correlation between the estimated and real results was very good.Une branche importante de la technologie textile est la géométrie de la structure du fil ou elle se voit affectée avec le change de système de filature, ce qui peut modifier le diamètre de la section de filage et la déformation de sa surface. Dans le travail antérieur (partie 1) nous abordons un système nouveau et les équations pour calculer les diamètres de la section elliptique du filage d'anneau de coton. Dans ce travail nous adapterons, avec quelques modifications, ces équations pour qu'elles soient plus adéquates pour leur application dans les fils du rotor entends. À partir des résultats, les diamètres plus grand et plus petit (D, d) des filages OE sont plus grands que dans les filages d'anneau RS, par conséquent, les constantes dans les équations changeront; l'ajustage a été très proche d'un et l'excentricité a été plus proche de 0,5. La simulation et la corrélation entre les résultats estimés et réels ont été très élevées.Peer Reviewe
Synthesis of Manufacturing Systems Using Co-Platforming
Modern manufacturing environment is characterized by frequent changes within product design in order to satisfy evolving customer requirements. Various strategies are implemented in order to efficiently manage the consequences arising from the product design changes starting from design of the product, planning, manufacturing…etc. This dissertation focuses mainly on the manufacturing phase in which a new concept in manufacturing system synthesis is proposed. A new concept in manufacturing system synthesis has been introduced and coined as “Co-platforming”. Co-platforming is the synthesis of manufacturing systems through mapping product platform features and components to platform machines on one side, and non-platform product features and components to non-platform machines on the other side, in order to reduce the manufacturing system investment cost and prolong the manufacturing system useful life as product variants evolve and change. Tools and methods are developed to synthesize the manufacturing system based on Co-platforming within functional and physical levels. At the functional level, the group of platform and non-platform machines and the number of each machine type are determined. A new matrix based mapping model is proposed to determine the platform and non-platform machines candidates. A ranking coefficient is formulated which ranks the platform machines according to their machining capabilities in order to assist manufacturing firms in decision making concerning which type of platform machine to choose. Furthermore, a new mathematical programming optimization model is proposed in order to provide the optimum selection of machine types among machine candidates and their numbers. Moreover, a new mathematical programming model is proposed which synthesizes manufacturing systems taking into consideration machine level and system level changes based on co-platforming. At the physical level, the manufacturing system configuration is determined which is concerned with determining the number of stages, types of machines in each stage and the number of machines in each stage. A new mathematical programming optimization model is proposed which determines, in addition to the type and number of each machine, the optimal manufacturing system configuration based on co-platforming. The Co-platforming methodology is being applied in two case studies from automotive industry. The first case study is concerned with machining of automotive cylinder blocks taken from Mitsubishi Heavy Industries and the second case study is concerned with the assembly of automotive cylinder heads taken from ABB flexible automation. The results obtained from the co-platforming methodology indicate that cost reduction can be achieved when synthesizing the manufacturing system based on co-platforming
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