96 research outputs found

    Uncertainty management in connectionist expert system

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    A connectionist expert system is an expert system whose knowledge base is generated from training examples using an artificial neural network learning technique. Gallant [13] developed a model for a connectionist expert system in which a variable is represented by a node and accepts two values, true or false. This study adopts two approaches to help manage uncertainty in Gallant's model. The first approach is called the random cell method while the second one is the stairstep method.Computer Scienc

    Congestion relief in CDMA cellular networks using multihop inter-cell relay

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    Abstract-Multihop communication has been proposed in cellular networks to overcome some inherent limitations. Congestion relief is amongst the promised gains. In this paper, the concept of inter-cell relay, which uses multihop communication to divert calls from heavy loaded cells to less loaded adjacent cells, is introduced. We show that using inter-cell relay, the number of supported calls inside a congested cell can be significantly increased. We devise two approaches for congestion relief based on the conditions of the network, to maximize the number of supported calls inside a congested cell. The distribution-based approach determines the number of extra hops for inter-cell relay based on call distribution. On the other hand, the delay sensitive approach assumes that the number of extra hops for inter-cell relay is limited by calls quality of service requirements. By imposing a limit on the number of extra hops, the approach decides the number of inter-cell relayed calls and the number of calls connected to the congested BS. Our results illustrate the benefits gained from inter-cell relay in congestion relief. We demonstrate that inter-cell relay can decrease congestion of a cell by fully utilizing the available resources in surrounding cells

    Energy Efficient Mobility Management for the Macrocell – Femtocell LTE Network

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    Femtocells will play a key role in future deployments of the 3rd Generation Partnership Project (3GPP) the Long Term Evolution (LTE) system, as they are expected to enhance system capacity, and greatly improve the energy-efficiency in a cost-effective manner. Due to the short transmit-receive distance, femtocells prolong handset battery life and enhance the Quality of Service (QoS) perceived by the end users. However, large-scale femtocell deployment comprises many technical challenges, mainly including security, interference and mobility management. Under the viewpoint of energy-efficient mobility management, this chapter discusses the key features of the femtocell technology and presents a novel energy-efficient handover decision policy for the macrocell – femtocell LTE network. The proposed HO decision policy aims at reducing the transmit power of the LTE mobile terminals in a backwards compatible with the standard LTE handover decision procedure. Simulation results show that significantly lower energy and power consumption can be attained if the proposed approach is employed, at the cost of a moderately increased number of handover executions events

    Fiber Bragg Gratings as e-Health Enablers: An Overview for Gait Analysis Applications

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    Nowadays, the fast advances in sensing technologies and ubiquitous wireless networking are reflected in medical practice. It provides new healthcare advantages under the scope of e-Health applications, enhancing life quality of citizens. The increase of life expectancy of current population comes with its challenges and growing health risks, which include locomotive problems. Such impairments and its rehabilitation require a close monitoring and continuous evaluation, which add financial burdens on an already overloaded healthcare system. Analysis of body movements and gait pattern can help in the rehabilitation of such problems. These monitoring systems should be noninvasive and comfortable, in order to not jeopardize the mobility and the day-to-day activities of citizens. The use of fiber Bragg gratings (FBGs) as e-Health enablers has presented itself as a new topic to be investigated, exploiting the FBGs’ advantages over its electronic counterparts. Although gait analysis has been widely assessed, the use of FBGs in biomechanics and rehabilitation is recent, with a wide field of applications. This chapter provides a review of the application of FBGs for gait analysis monitoring, namely its use in topics such as the monitoring of plantar pressure, angle, and torsion and its integration in rehabilitation exoskeletons and for prosthetic control

    Concentrating solar power (CSP) technologies: Status and analysis

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    Concentrated solar power (CSP) technology is a promising renewable energy technology worldwide. However, many challenges facing this technology nowadays. These challenges are mentioned in this review study. For the first time, this work summarized and compared around 143 CSP projects worldwide in terms of status, capacity, concentrator technologies, land use factor, efficiency, country and many other factors. Further, the various challenges facing the spread-out of this system are highlighted in terms of the heat transfer fluids (HTF), various energy storage (ES) technologies, cooling techniques, water management, and the Levelized Cost of Electricity (LCOE). Also, various thermophysical properties of the HTF are compared within the applicable range of the CSP operation. At the end of the review, various hybridization technologies for the CSP with various renewable energy sources, including photovoltaic, wind, and geothermal, are highlighted and compared. The pioneering country in using CSP, leading concentrator technology, suitable ES technology, and efficient hybrid technique based on the LCOE are determined. The analyzed data in this study is essential for predicting the future of the CSP in the markets and its contribution to reducing global warming potential
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