18,969 research outputs found

    Wireless Health Monitoring using Passive WiFi Sensing

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    This paper presents a two-dimensional phase extraction system using passive WiFi sensing to monitor three basic elderly care activities including breathing rate, essential tremor and falls. Specifically, a WiFi signal is acquired through two channels where the first channel is the reference one, whereas the other signal is acquired by a passive receiver after reflection from the human target. Using signal processing of cross-ambiguity function, various features in the signal are extracted. The entire implementations are performed using software defined radios having directional antennas. We report the accuracy of our system in different conditions and environments and show that breathing rate can be measured with an accuracy of 87% when there are no obstacles. We also show a 98% accuracy in detecting falls and 93% accuracy in classifying tremor. The results indicate that passive WiFi systems show great promise in replacing typical invasive health devices as standard tools for health care.Comment: 6 pages, 8 figures, conference pape

    HEER: Hybrid Energy Efficient Reactive Protocol for Wireless Sensor Networks

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    Wireless Sensor Networks (WSNs) consist of numerous sensors which send sensed data to base station. Energy conservation is an important issue for sensor nodes as they have limited power.Many routing protocols have been proposed earlier for energy efficiency of both homogeneous and heterogeneous environments. We can prolong our stability and network lifetime by reducing our energy consumption. In this research paper, we propose a protocol designed for the characteristics of a reactive homogeneous WSNs, HEER (Hybrid Energy Efficient Reactive) protocol. In HEER, Cluster Head(CH) selection is based on the ratio of residual energy of node and average energy of network. Moreover, to conserve more energy, we introduce Hard Threshold (HT) and Soft Threshold (ST). Finally, simulations show that our protocol has not only prolonged the network lifetime but also significantly increased stability period.Comment: 2nd IEEE Saudi International Electronics, Communications and Photonics Conference (SIECPC 13), 2013, Riyadh, Saudi Arabi

    Analyzing Energy-efficiency and Route-selection of Multi-level Hierarchal Routing Protocols in WSNs

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    The advent and development in the field of Wireless Sensor Networks (WSNs) in recent years has seen the growth of extremely small and low-cost sensors that possess sensing, signal processing and wireless communication capabilities. These sensors can be expended at a much lower cost and are capable of detecting conditions such as temperature, sound, security or any other system. A good protocol design should be able to scale well both in energy heterogeneous and homogeneous environment, meet the demands of different application scenarios and guarantee reliability. On this basis, we have compared six different protocols of different scenarios which are presenting their own schemes of energy minimizing, clustering and route selection in order to have more effective communication. This research is motivated to have an insight that which of the under consideration protocols suit well in which application and can be a guide-line for the design of a more robust and efficient protocol. MATLAB simulations are performed to analyze and compare the performance of LEACH, multi-level hierarchal LEACH and multihop LEACH.Comment: NGWMN with 7th IEEE Inter- national Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA 2012), Victoria, Canada, 201

    Acute myocardial infarction: profile and management at a tertiary care hospital in Karachi

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    Objective: Acute Myocardial Infarction (AMI) is a rising epidemic in developing countries. While studies in the West have established the characteristics and management of AMI patients, comprehensive data reflecting these issues in the Pakistani subjects is scarce. This study examined the profile and management of AMI in patients hospitalized at a tertiary care hospital in Karachi, Pakistan.Methods: Three hundred forty four patients admitted in 1998 with the diagnosis of AMI met our inclusion criteria. Data on presentation, investigations, monitoring and therapy was obtained. Chi-square and t tests were used to analyze the data.Results: Out of 344 patients with AMI, 71% were males; 58% had a Q wave MI. Majority of the patients who presented within 2 hours of symptom onset (36%), had chest pain. Patients with dyspnea and no chest pain were more likely to present after 12 hours of the onset of symptoms. In-house mortality was found to be 10.8%. Low HDL and diabetes was associated with in-hospital complications. Twenty nine percent of patients were given thrombolytic therapy with a mean door-to-needle time of 1 hour 36 minutes; 33% of patients who were eligible of Streptokinase did not receive it. Cardiac catheterization was performed in 28% patients. Echocardiography and Exercise Tolerance Test, both under utilized, were performed in 67% and 16% of patients, respectively. Two hundred sixteen (70%) patients discharged from hospital were contacted via telephone and the 1-year mortality rate among them was 28%.CONCLUSION: The profile and management of AMI was in coherence with earlier, Western studies. Chest pain units need to be established in the Emergency Room. Patients should be risk stratified prior to discharge. Public awareness regarding primary and secondary prevention and symptoms of AMI needs to be increased

    Chemical and biological warfare preparing to meet the threat

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    Heavy-light meson decay constants from NRQCD: an analysis of the 1/M corrections

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    We present {\it preliminary} results for the decay constants of heavy-light mesons using NRQCD heavy and tadpole improved Clover light quarks. A comparison is made with data obtained using Wilson light quarks. We present an analysis of the 1/M corrections to the decay constants in the static limit and compare with the predictions of HQET.Comment: Contribution to Lattice 95, 4 pages uuencoded compressed postscript fil
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