521 research outputs found

    A Decoupled Parameters Estimators for in Nonlinear Systems Fault diagnosis by ANFIS

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    This paper presents a new and efficient Adaptive Neural Fuzzy Inference Systems approach for satellite’s attitude control systems (ACSs) fault diagnosis. The proposed approach formulates the fault modelling problem of system component into an on-line parameters estimation The learning  ability of the adaptive neural fuzzy inference system allow as to decoupling the effect of each fault from the estimation of the others.  Our solution provides a method to detect, isolate, and estimate various faults in system components, using Adaptive Fuzzy Inference Systems Parameter Estimators (ANFISPEs) that are designed and based on parameterizations related to each class of fault. Each ANFISPE estimates the corresponding unknown Fault Parameter (FP) that is further used for fault detection, isolation and identification purposes. Simulation results reveal the effectiveness of the developed FDI scheme of an ACSs actuators of a 3-axis stabilized satellite.DOI:http://dx.doi.org/10.11591/ijece.v2i2.22

    Explaining semantic short-term memory deficits:evidence for the critical role of semantic control

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    Patients with apparently selective short-term memory (STM) deficits for semantic information have played an important role in developing multi-store theories of STM and challenge the idea that verbal STM is supported by maintaining activation in the language system. We propose that semantic STM deficits are not as selective as previously thought and can occur as a result of mild disruption to semantic control processes, i.e., mechanisms that bias semantic processing towards task-relevant aspects of knowledge and away from irrelevant information. We tested three semantic STM patients with tasks that tapped four aspects of semantic control: (i) resolving ambiguity between word meanings, (ii) sensitivity to cues, (iii) ignoring irrelevant information and (iv) detecting weak semantic associations. All were impaired in conditions requiring more semantic control, irrespective of the STM demands of the task, suggesting a mild, but task-general, deficit in regulating semantic knowledge. This mild deficit has a disproportionate effect on STM tasks because they have high intrinsic control demands: in STM tasks, control is required to keep information active when it is no longer available in the environment and to manage competition between items held in memory simultaneously. By re-interpreting the core deficit in semantic STM patients in this way, we are able to explain their apparently selective impairment without the need for a specialised STM store. Instead, we argue that semantic STM patients occupy the mildest end of spectrum of semantic control disorders

    Self-control in decision-making involves modulation of the vmPFC valuation system

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    Every day, individuals make dozens of choices between an alternative with higher overall value and a more tempting but ultimately inferior option. Optimal decision-making requires self-control. We propose two hypotheses about the neurobiology of self-control: (i) Goal-directed decisions have their basis in a common value signal encoded in ventromedial prefrontal cortex (vmPFC), and (ii) exercising self-control involves the modulation of this value signal by dorsolateral prefrontal cortex (DLPFC). We used functional magnetic resonance imaging to monitor brain activity while dieters engaged in real decisions about food consumption. Activity in vmPFC was correlated with goal values regardless of the amount of self-control. It incorporated both taste and health in self-controllers but only taste in non–self-controllers. Activity in DLPFC increased when subjects exercised self-control and correlated with activity in vmPFC

    Performance of \u3cem\u3eAcacia senegal\u3c/em\u3e L.: Untapped Wealth of Gum Arabic in Rangelands and Grasslands in Arid and Semi-Arid Region of India

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    Acacia senegal (Linn) Wild a member of Mimosaceae is a small tree of 3-6m in height with umbrella-shaped crown. It is a typical tree of Sahel in Africa from Senegal to red sea and essentially limited to the area between 110 and 160 North, with a wide range of rainfall 100 to 800mm. It spread widely in tropical Africa from Mozambique, Zambia to Somalia, Sudan, Ethiopia, Kenya, Tanzania and Nigeria, and in South Asia in India and Pakistan. In India it is a typical tree of arid regions with a low rainfall of 100-250mm. It is drought resistant and tolerates prolonged dry period of 10-11 months, with maximum temperature reaching 500C with strong winds, but susceptible to frost. It occurs mostly on sand stones and skeletal soils and widely distributed as interspersed species in most of the rangelands and grasslands in arid and semi-arid regions of India. World’s 90% gum Arabic is produced from Acacia senegal. The quality of gum is very superior as compared to gum from any other species of Acacia (Andreson, 1990). Nearly 90% of gum Arabic is produced by Republic of Sudan especially from (Kordafan). Production of gum Arabic is meagre in India, and contribution to the world production is negligible. The total annual output of gum Arabic is only 800 Mt compared to world production and consumption of 60,000-70,000 Mt. The domestic production is insufficient even for domestic consumption and more of it is imported from Sudan and Nigeria to meet India\u27s requirements. Gum exudes from cracks in bark of trees, mostly in the dry season. In Sudan the annual yields from young trees ranges from 188 to 2856 g (av. 0.9 kg), and from older trees, 379 to 6754 g (av. 2.0 kg). In India, however, the productivity is low varying from 175 to 550g tree-1 year-1. The main gum producing regions of India where natural as well as planted stands of A. senegal occur are in desert and arid region of Rajasthan, Gujarat, Haryana, and Punjab. The gum yield from various Acacia trees in their natural habitat is very poor. In arid and semi-arid region of India, particularly in Rajasthan, Gujarat, Haryana, Punjab and Bundelkahand, there is a good scope for extending area for large- scale plantation for production of gum Arabic. The area covered under forest, barren and uncultivable, pasture, oren (temple lands) and community grazing land etc, can be used for commercial plantation of A. senegal. The arid zone of Western Rajasthan is prone to frequent drought and famine and cultivation of gum Arabic can provide livelihood security to desert dwellers. A farmer who has planted 100 trees/ ha at spacing of 10 x 10 m can harvest about 25kg gum assuming average yield of 250g per tree. This would generate revenue of Rs 10000 ha-1 year-1 if, gum is sold at a minimum price of Rs. 400 kg-1. In addition, systematic commercial plantation of Acacia senegal can also provide employment to millions of people towards various planting activities and gum collection. According to an estimate of FAO, gum collection sustains about 0.3 million people and has huge potential of employment. Integration of Acacia senegal in traditional grazing grounds such as orens and gochars, systematically raised silvopastoral systems and other agroforestry landuse for production of gum Arabic can be a profitable proposition. It will not only provide alternative livelihood options to local people but also increase economic viability and sustainability grasslands and pastures. In consideration of wide variations in gum production in respect to sites, annual rainfall and geographical locations, it imperative to study growth performance of A. senegal in different eco-regions and develop site specific models for optimizing production of gum Arabic. This study is a part of research efforts being made at Central Agroforestry Research Institute, Jhansi, which is one of the co-ordinating centres in the ICAR-network project on Natural Resin and Gums headquartered at Indian Institute of Natural Resin and Gums, Ranchi. The main objective is to develope suitable agroforestry models based on gums and resins yielding trees for Bundelkhand region. This paper presents growth performance of A. senegal in semi-arid region of Bundelkhand, Central India

    Remembering 'zeal' but not 'thing':reverse frequency effects as a consequence of deregulated semantic processing

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    More efficient processing of high frequency (HF) words is a ubiquitous finding in healthy individuals, yet frequency effects are often small or absent in stroke aphasia. We propose that some patients fail to show the expected frequency effect because processing of HF words places strong demands on semantic control and regulation processes, counteracting the usual effect. This may occur because HF words appear in a wide range of linguistic contexts, each associated with distinct semantic information. This theory predicts that in extreme circumstances, patients with impaired semantic control should show an outright reversal of the normal frequency effect. To test this prediction, we tested two patients with impaired semantic control with a delayed repetition task that emphasised activation of semantic representations. By alternating HF and low frequency (LF) trials, we demonstrated a significant repetition advantage for LF words, principally because of perseverative errors in which patients produced the previous LF response in place of the HF target. These errors indicated that HF words were more weakly activated than LF words. We suggest that when presented with no contextual information, patients generate a weak and unstable pattern of semantic activation for HF words because information relating to many possible contexts and interpretations is activated. In contrast, LF words tend are associated with more stable patterns of activation because similar semantic information is activated whenever they are encountered

    LES PANCREATITES MEDICAMENTEUSES DIFFICULTES DIAGNOSTIQUES ET THERAPEUTIQUES

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    Les pancrĂ©atites mĂ©dicamenteuses sont rares mais potentiellement graves. Plusieurs mĂ©dicaments sont incriminĂ©s. Le diagnostic positif repose sur l’établissement d’un lien entre le mĂ©dicament et la pancrĂ©atite aiguĂ« et sur la consultation des centres de pharmacovigilance et des revues de la littĂ©rature. Le but de notre travail est de rappeler les diffĂ©rentes Ă©tapes du diagnostic et d’insister sur l’importance de la pharmacovigilance. La difficultĂ© diagnostique rĂ©side dans le fait que les manifestations cliniques des pancrĂ©atites mĂ©dicamenteuses sont peu spĂ©cifiques. De plus, le lien entre un mĂ©dicament et la survenue d’une pancrĂ©atite mĂ©dicamenteuse peut ĂȘtre difficile Ă  Ă©tablir. Il repose sur plusieurs critĂšres : sĂ©miologiques, chronologiques et bibliographiques.Une liste de mĂ©dicaments de plus en plus Ă©tendue est mise en cause. Cette liste ne saurait ĂȘtre exhaustive car chaque jour, de nouvelles molĂ©cules sont signalĂ©es aux centres de pharmacovigilance. La prise en charge des pancrĂ©atites mĂ©dicamenteuses comprend un volet symptomatique mais aussi un volet Ă©tiologique qui consiste en un arrĂȘt immĂ©diat du mĂ©dicament en cause.The drug-induced pancreatitis are rare but potentially serious. Several drugs are accused. The positive diagnosis rests on: - Establishment of a bond between the drug and the acute pancreatitis. -Consultation of centers of pharmacovigilance and reviews of literature. The aim of our work is to point out the various stages of the diagnosis and to insist on the importance of the pharmacovigilance. The diagnostic difficulty lies in the fact that the clinical demonstrations of the drug-induced pancreatitis are not very specific. Moreover, the bond between a drug and occurred of a drug-induced pancreatitis can be difficult to establish.  It rests on several criteria: semiological, chronological and bibliographical. Un increasingly wide list of drugs is blamed. This list could not be exhaustive because each day, of new molecules are announced to the centers of pharmacovigilance. The assumption of responsibility of the drug-induced pancreatitis comprises a symptomatic aspect but also a shutter etiologic which consists of a dead halt of the drug in question

    Lateral Prefrontal Cortex Subregions Make Dissociable Contributions during Fluid Reasoning

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    Reasoning is a key component of adaptable “executive” behavior and is known to depend on a network of frontal and parietal brain regions. However, the mechanisms by which this network supports reasoning and adaptable behavior remain poorly defined. Here, we examine the relationship between reasoning, executive control, and frontoparietal function in a series of nonverbal reasoning experiments. Our results demonstrate that, in accordance with previous studies, a network of frontal and parietal brain regions is recruited during reasoning. Our results also reveal that this network can be fractionated according to how different subregions respond when distinct reasoning demands are manipulated. While increased rule complexity modulates activity within a right lateralized network including the middle frontal gyrus and the superior parietal cortex, analogical reasoning demand—or the requirement to remap rules on to novel features—recruits the left inferior rostrolateral prefrontal cortex and the lateral occipital complex. In contrast, the posterior extent of the inferior frontal gyrus, associated with simpler executive demands, is not differentially sensitive to rule complexity or analogical demand. These findings accord well with the hypothesis that different reasoning demands are supported by different frontal and parietal subregions

    Carbon Modeling of Agroforestry Systems at Farmers’ Field in Indo-Gangetic Plains of India

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    The Indian Green revolution region “Indo-Gangetic Plain” (IGP) comprises of four agro-climatic zones namely lower, middle, upper, and trans gangetic plains covering West Bengal, Bihar, Uttar Pradesh, Delhi, Uttarakhand, Chandigarh, Haryana, Punjab, and some part of Rajasthan state. It covers 169 districts with total geographical area of 43.70 million ha. The Indo-Gangetic plains are one of the most populous regions with its area covering nearly 13% of the total geographical area of the country. It produces about 50% of the total food grains to feed 40% of the population. The continuous cropping of rice-wheat system has degraded the soil health dramatically over the years. Hence, the incorporation of trees in agriculture would be a better option to improve the soil as well as livelihood of the farmers in IGP. Agriculture is the major enterprise of the region that is most vulnerable to climate changes particularly owing to the inadequacy of resources with the smallholder farmers. While, agroforestry has the potential to play a significant role in mitigating the atmospheric accumulation of greenhouse gases (GHG), it also helps smallholder farmers adapt to the changes. These are the reasons for recognizing agroforestry as a viable alternative to prevent and mitigate climate change (Ram Newaj et al., 2014). A considerable proportion of agroforestry area located in IGP and some of the promising tree species like Populus deltoides, Eucalyptus tereticornis, Melia azadirach, Mangifera indica, Dalbergia sissoo, and Acacia nilotica are very common in the farmer’s fields. Keeping this in view, the field survey was carried out to estimate the carbon sequestration potential at a farmer’s field in IGP

    The special case of self-perspective inhibition in mental, but not non-mental, representation

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    The ventrolateral prefrontal cortex (vlPFC) has been implicated in studies of both executive and social functions. Recent meta-analyses suggest that vlPFC plays an important but little understood role in Theory of Mind (ToM). Converging neuropsychological and functional Magnetic Resonance Imaging (fMRI) evidence suggests that this may reflect inhibition of self-perspective. The present study adapted an extensively published ToM localizer to evaluate the role of vlPFC in inhibition of self-perspective. The classic false belief, false photograph vignettes that comprise the localizer were modified to generate high and low salience of self-perspective. Using a factorial design, the present study identified a behavioural and neural cost associated with having a highly salient self-perspective that was incongruent with the representational content. Importantly, vlPFC only differentiated between high versus low salience of self-perspective when representing mental state content. No difference was identified for non-mental representation. This result suggests that different control processes are required to represent competing mental and non-mental content
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