106 research outputs found

    Automatic Generation Control of Multi-Area Power System with Generating Rate Constraints Using Computational Intelligence Techniques

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    In a large inter-connected system, large and small generating stations are synchronously connected and hence all stations must have the same frequency. The system frequency deviation is the sensitive indicator of real power imbalance. The main objectives of AGC are to maintain constant frequency and tie-line errors with in prescribed limit. This paper presents two new approaches for Automatic Generation Control using i) combined Fuzzy Logic and Artificial Neural Network Controller (FLANNC) and ii) Hybrid Neuro Fuzzy Controller (HNFC) with gauss membership functions. The simulation model is created for four-area interconnected power system. In this four area system, three areas consist of steam turbines and one area consists of hydro turbine. The components of ACE, frequency deviation (F) and tie line error (Ptie) are obtained through simulation model and used to produce the required control action to achieve AGC using i) FLANNC and ii) HNFC with gauss membership functions. The simulation results show that the proposed controllers overcome the drawbacks associated with conventional integral controller, Fuzzy Logic Controller (FLC), Artificial Neural Network controller (ANNC) and HNFC with gbell membership functions.

    Environment Impacts the Metabolic Dependencies of Ras-Driven Non-Small Cell Lung Cancer

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    Cultured cells convert glucose to lactate, and glutamine is the major source of tricarboxylic acid (TCA)-cycle carbon, but whether the same metabolic phenotype is found in tumors is less studied. We infused mice with lung cancers with isotope-labeled glucose or glutamine and compared the fate of these nutrients in tumor and normal tissue. As expected, lung tumors exhibit increased lactate production from glucose. However, glutamine utilization by both lung tumors and normal lung was minimal, with lung tumors showing increased glucose contribution to the TCA cycle relative to normal lung tissue. Deletion of enzymes involved in glucose oxidation demonstrates that glucose carbon contribution to the TCA cycle is required for tumor formation. These data suggest that understanding nutrient utilization by tumors can predict metabolic dependencies of cancers in vivo. Furthermore, these data argue that the in vivo environment is an important determinant of the metabolic phenotype of cancer cells.National Science Foundation (U.S.) (Grant T32GM007287

    Direct correlation between the circadian sleep-wakefulness rhythm and time estimation in humans under social and temporal isolation

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    Several bodily functions in humans vary on a 24 h pattern and most of these variations persist with a circadian period of ca 25 h when subjects are studied under conditions of social and temporal isolation. We report in this paper that the estimates of short time intervals (TE) of 2 h are strongly coupled to the circadian rhythm in sleepwakefulness. There is a linear correlation between the number of hours humans stay awake (α) and their estimation of 2 h intervals. The coupling of TE to α appears to obtain only under conditions of physical well-being

    Tracheostomal Myiasis: A Case Report and Review of the Literature

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    “Myiasis” is considered in Hindu mythology as “God's punishment for sinners.” It is known to infest live human or animal tissue. Literature abounds with reports of myiasis affecting the nasal cavity, ear, nonhealing ulcers, exophytic malignant growth, and cutaneous tissue. But report of myiasis of the tracheal stoma is rare. Only a few cases of tracheal myiasis have been reported in literature. We report a case of tracheostomal myiasis in an elderly male. The species which had infested the stoma was identified as Chrysomya bezziana, an obligate parasite. This is to our knowledge the first case report of an obligate parasite (Chrysomya bezziana) infestation of the tracheostoma from India

    Numerical Simulation of Asymmetrically Altered Growth as Initiation Mechanism of Scoliosis

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    The causes of idiopathic scoliosis are still uncertain; buckling is mentioned often, but never proven. The authors hypothesize another option: unilateral postponement of growth of MM Rotatores or of ligamentum flavum and intertransverse ligament. In this paper, both buckling and the two new theories of scoliotic initiation are studied using a new finite element model that simulates the mechanical behavior of the human spine. This model was validated by the stiffness data of Panjabi et al. (J. Biomech. 9:185–192, 1976). After a small correction of the prestrain of some ligaments and the MM Rotatores the model appeared to be valid. The postponement in growth was translated in the numerical model in an asymmetrical stiffness. The spine was loaded axially and the resulting deformation was analyzed for the presence of the coupling of lateral deviation and axial rotation that is characteristic for scoliosis. Only unilateral postponement of growth of ligamentum flavum and intertransverse ligament appeared to initiate scoliosis. Buckling did not initiate scoliosis

    ADAPTIVE NEURO-FUZZY INFERENCE SYSTEM APPROACH FOR FAULT DETECTION AND DIAGNOSIS OF PNEUMATIC VALVE IN CEMENT INDUSTRY

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    The detection and diagnosis of faults in technical systems are of great practical significance and paramount importance for the safe operation of the plant. The early detection of fault can help avoid system shutdown, breakdown and even catastrophe involving human fatalities and material damage. Since the operator cannot monitor all the variables simultaneously, an automated approach is needed for the real time monitoring and diagnosis of the system. This paper presents the design and development of adaptive neuro-fuzzy inference system (ANFIS) model based for the fault detection of pneumatic valve in cooler water spray system in cement industry. The fault detection model is developed by using two different approaches, namely, ANFIS and feed forward network with back propagation algorithm (BPN). The training and testing data required are developed for the ANFIS model and BPN model that were generated at different operating conditions by operating the pneumatic valve and by creating various faults in real time in a laboratory experimental model. The performance of the developed ANFIS model and back propagation were tested and also compared for a total of 19 faults in pneumatic valve used in cooler water spray system. Obtained results of the ANFIS performed better than BPN. </jats:p
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