4,908 research outputs found

    Optimisation of Mobile Communication Networks - OMCO NET

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    The mini conference “Optimisation of Mobile Communication Networks” focuses on advanced methods for search and optimisation applied to wireless communication networks. It is sponsored by Research & Enterprise Fund Southampton Solent University. The conference strives to widen knowledge on advanced search methods capable of optimisation of wireless communications networks. The aim is to provide a forum for exchange of recent knowledge, new ideas and trends in this progressive and challenging area. The conference will popularise new successful approaches on resolving hard tasks such as minimisation of transmit power, cooperative and optimal routing

    State-of-the-Art System Solutions for Unmanned Underwater Vehicles

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    Unmanned Underwater Vehicles (UUVs) have gained popularity for the last decades, especially for the purpose of not risking human life in dangerous operations. On the other hand, underwater environment introduces numerous challenges in navigation, control and communication of such vehicles. Certainly, this fact makes the development of these vehicles more interesting and engineering-wise more attractive. In this paper, we first revisit the existing technology and methodology for the solution of aforementioned problems, then we try to come up with a system solution of a generic unmanned underwater vehicles

    An Adaptive Intelligent Integrated Lighting Control Approach for High-Performance Office Buildings

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    abstract: An acute and crucial societal problem is the energy consumed in existing commercial buildings. There are 1.5 million commercial buildings in the U.S. with only about 3% being built each year. Hence, existing buildings need to be properly operated and maintained for several decades. Application of integrated centralized control systems in buildings could lead to more than 50% energy savings. This research work demonstrates an innovative adaptive integrated lighting control approach which could achieve significant energy savings and increase indoor comfort in high performance office buildings. In the first phase of the study, a predictive algorithm was developed and validated through experiments in an actual test room. The objective was to regulate daylight on a specified work plane by controlling the blind slat angles. Furthermore, a sensor-based integrated adaptive lighting controller was designed in Simulink which included an innovative sensor optimization approach based on genetic algorithm to minimize the number of sensors and efficiently place them in the office. The controller was designed based on simple integral controllers. The objective of developed control algorithm was to improve the illuminance situation in the office through controlling the daylight and electrical lighting. To evaluate the performance of the system, the controller was applied on experimental office model in Lee et al.’s research study in 1998. The result of the developed control approach indicate a significantly improvement in lighting situation and 1-23% and 50-78% monthly electrical energy savings in the office model, compared to two static strategies when the blinds were left open and closed during the whole year respectively.Dissertation/ThesisDoctoral Dissertation Architecture 201

    Optimal Wideband LPDA Design for Efficient Multimedia Content Delivery over Emerging Mobile Computing Systems

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    An optimal synthesis of a wideband Log-Periodic Dipole Array (LPDA) is introduced in the present study. The LPDA optimization is performed under several requirements concerning the standing wave ratio, the forward gain, the gain flatness, the front-to-back ratio and the side lobe level, over a wide frequency range. The LPDA geometry that complies with the above requirements is suitable for efficient multimedia content delivery. The optimization process is accomplished by applying a recently introduced method called Invasive Weed Optimization (IWO). The method has already been compared to other evolutionary methods and has shown superiority in solving complex non-linear problems in telecommunications and electromagnetics. In the present study, the IWO method has been chosen to optimize an LPDA for operation in the frequency range 800-3300 MHz. Due to its excellent performance, the LPDA can effectively be used for multimedia content reception over future mobile computing systems

    PID Controlled Adaptive Time-Stepping in Coupled Surface-Subsurface Simulation: A Tool for Reducing Non-Physical Oscillation

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    Surface-subsurface coupling in simulation is required to model large, complex and often offshore projects. The most optimal form of coupling is the partially implicit method. The partially implicit method typically balances accuracy and computational costs. However, the partially implicit method can suffer from non-physical oscillations. Nonphysical oscillations are a result of incorrect assumptions made during coupled simulation. Non-physical oscillations are solely artifacts of less than ideal coupled simulation- they do not have physical significance. As such, non-physical oscillations in coupling are treated as simulation complications, as opposed to reservoir or network dynamics. Although many coupling solutions exist, many are complex and difficult to implement in commercial software packages. In this study, we investigate the use of PID control to select time-steps in coupled surface-subsurface simulation. PID control is not often used in oil and gas applications, however it is well established in other engineering fields. The PID controller performs automatic, adaptive time-stepping in the coupled simulation. The controller operated by reducing oscillations in coupling error. The results show that the PID controlled time-stepping reduces non-physical oscillations, the total number of time-steps executed, and the computational cost of coupled simulation. Importantly, one PID controlled experiment decreased simulation time by 300%, with less than 0.5% error (in cumulative production) as compared to Schlumberger’s standard coupling settings. We performed a set of manual tuning experiments that highlight opportunity for controller optimization, as well as motivate future work. The PID controlled coupled simulation we created can be implemented in any software where the user can select the time-steps

    Development of Advanced Verification and Validation Procedures and Tools for the Certification of Learning Systems in Aerospace Applications

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    Adaptive control technologies that incorporate learning algorithms have been proposed to enable automatic flight control and vehicle recovery, autonomous flight, and to maintain vehicle performance in the face of unknown, changing, or poorly defined operating environments. In order for adaptive control systems to be used in safety-critical aerospace applications, they must be proven to be highly safe and reliable. Rigorous methods for adaptive software verification and validation must be developed to ensure that control system software failures will not occur. Of central importance in this regard is the need to establish reliable methods that guarantee convergent learning, rapid convergence (learning) rate, and algorithm stability. This paper presents the major problems of adaptive control systems that use learning to improve performance. The paper then presents the major procedures and tools presently developed or currently being developed to enable the verification, validation, and ultimate certification of these adaptive control systems. These technologies include the application of automated program analysis methods, techniques to improve the learning process, analytical methods to verify stability, methods to automatically synthesize code, simulation and test methods, and tools to provide on-line software assurance

    Proceedings of the Second Joint Technology Workshop on Neural Networks and Fuzzy Logic, volume 2

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    Documented here are papers presented at the Neural Networks and Fuzzy Logic Workshop sponsored by NASA and the University of Texas, Houston. Topics addressed included adaptive systems, learning algorithms, network architectures, vision, robotics, neurobiological connections, speech recognition and synthesis, fuzzy set theory and application, control and dynamics processing, space applications, fuzzy logic and neural network computers, approximate reasoning, and multiobject decision making

    Smart Station for Data Reception of the Earth Remote Sensing

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