2,434 research outputs found

    Analysis of ITU-R Performance and Characterization of Ku Band Satellite Downlink Signals during Rainy Season over Chennai Region of India

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    In this paper, we present the analysis of Ku band Satellite signal reception during rainy season over Chennai region, India (Latitude: 12° 56' 60 N, Longitude: 80° 7' 60 E). We also examine the effectiveness of International Telecommunication Union – Radio communication (ITU-R) model in predicting the rainfall induced attenuation in Ku band, over this region. An improved Simulink model for Digital Video Broadcast – Satellite (DVB-S2) downlink channel incorporating rain attenuation and Cross Polarization Discrimination (XPD) effects is developed to study the rain attenuation effects, by introducing the experimental data in the ITU-R model pertaining to that region. Based on the improved model, a Monte Carlo simulation of the DVB–S2 signal link is carried out and the performance is analyzed by received constellation and Bit Error Rate (BER) parameters

    Diuretic Effects of Cleistanthin A and Cleistanthin B from the Leaves of Cleistanthus Collinus in Wistar Rats

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    To study the diuretic effects of cleistanthin A and cleistanthin B, phytoconstituents were isolated from the leaves of Cleistanthus collinus in Wistar rats. The in vivo diuretic effects of cleistanthins A and B were determined according to the Lipschitz test. Prior to the experiment, the animals were fasted for 5 h and placed individually in metabolic cages. Cleistanthins A and B (12.5, 25, and 50 mg/kg) and furosemide (5 mg/kg) were suspended in 0.5% w/v carboxymethyl cellulose and administered orally. The urine was collected up to 5 h after administration and subsequently up to 24 h after administration. The acidity and urine volume were measured immediately. The urinary sodium and potassium levels were determined using a flame photometer, and the chloride level was determined by argentometric titration. The diuretic index and diuretic activity were calculated mathematically. While cleistanthins A and B showed a diuretic index of more than one, the diuretic activity of these compounds was less than one, indicating inferior activity compared with furosemide. Both cleistanthin A and B produced a significant increase in the urine volume and alterations in urinary electrolyte levels. However, the effect of the compounds was not dose dependent. Cleistanthin A and cleistanthin B exert diuretic effects in male Wistar rats without affecting the urinary acidity

    Economic Marginalisation of Peasants and Fishermen Due to Urban Expansion: The JNP Project of New Bombay, India

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    The Central and State Governments in India have actively intervened in redefining land use pattern, often to the detriment of the peasant cultivators. In most situations, the real beneficiaries were the speculators, developers, builders, bureaucrats, and the planning and executing body. The case of New Bombay is a classic example of state intervention that completely redefined the relationship between land and peasant-cultivators. The New Bombay project acquired large amounts of agricultural and saltpan land from peasants in 95 villages for meagre cash compensation. The objective of the paper is to trace the origin of the idea—for the creation of New Bombay and a port to attract people and industry so as to decongest Bombay—and assess the condition of peasants who had lost land to the project. The study shows that the port, like most other modern industrial projects, seriously undermined the economic position of a large number of households. The small and marginal farmers and the fishermen were seriously affected due to others' land acquisition and their own loss of access to the sea, as well as denial of employment in the project. The project also failed to assess the skills and capacities of the affected people and facilitate them to engage in alternative productive activities. Women were productively engaged in agriculture, saltpan- and fishing-related activities in the affected villages. The loss of land and access to the sea have led to a greater degree of pauperisation of women, and increasingly confined them to the margins of the labour market.

    Attention and automation: New perspectives on mental underload and performance

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    There is considerable evidence in the ergonomics literature that automation can significantly reduce operator mental workload. Furthermore, reducing mental workload is not necessarily a good thing, particularly in cases where the level is already manageable. This raises the issue of mental underload, which can be at least as detrimental to performance as overload. However, although it is widely recognized that mental underload is detrimental to performance, there are very few attempts to explain why this may be the case. It is argued in this paper that, until the need for a human operator is completely eliminated, automation has psychological implications relevant in both theoretical and applied domains. The present paper reviews theories of attention, as well as the literature on mental workload and automation, to synthesize a new explanation for the effects of mental underload on performance. Malleable attentional resources theory proposes that attentional capacity shrinks to accommodate reductions in mental workload, and that this shrinkage is responsible for the underload effect. The theory is discussed with respect to the applied implications for ergonomics research

    REFERQUAL: A pilot study of a new service quality assessment instrument in the GP Exercise Referral scheme setting

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    Background The development of an instrument accurately assessing service quality in the GP Exercise Referral Scheme (ERS) industry could potentially inform scheme organisers of the factors that affect adherence rates leading to the implementation of strategic interventions aimed at reducing client drop-out. Methods A modified version of the SERVQUAL instrument was designed for use in the ERS setting and subsequently piloted amongst 27 ERS clients. Results Test re-test correlations were calculated via Pearson's 'r' or Spearman's 'rho', depending on whether the variables were Normally Distributed, to show a significant (mean r = 0.957, SD = 0.02, p < 0.05; mean rho = 0.934, SD = 0.03, p < 0.05) relationship between all items within the questionnaire. In addition, satisfactory internal consistency was demonstrated via Cronbach's 'α'. Furthermore, clients responded favourably towards the usability, wording and applicability of the instrument's items. Conclusion REFERQUAL is considered to represent promise as a suitable tool for future evaluation of service quality within the ERS community. Future research should further assess the validity and reliability of this instrument through the use of a confirmatory factor analysis to scrutinise the proposed dimensional structure

    Electromyography (EMG) based Classification of Neuromuscular Disorders using Multi-Layer Perceptron

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    Electromyography (EMG) signals are the measure of activity in the muscles. The aim of this study is to identify the neuromuscular disease based on EMG signals by means of classification. The neuromuscular diseases that have been identified are myopathy and neuropathy. The classification was carried out using Artificial Neural Network (ANN). There are five feature extraction techniques that were used to extract the signals such as Autoregressive (AR), Root Mean Square (RMS), Zero Crossing (ZC), Waveform length (WL) and Mean Absolute Value (MAV). A comparative analysis of these different techniques were carried out based on the results. The Multilayer Perceptron (MLP) was used for carrying out the classification
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