643 research outputs found

    An Achievable Rate Region for the Broadcast Channel with Feedback

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    A single-letter achievable rate region is proposed for the two-receiver discrete memoryless broadcast channel with generalized feedback. The coding strategy involves block-Markov superposition coding, using Marton's coding scheme for the broadcast channel without feedback as the starting point. If the message rates in the Marton scheme are too high to be decoded at the end of a block, each receiver is left with a list of messages compatible with its output. Resolution information is sent in the following block to enable each receiver to resolve its list. The key observation is that the resolution information of the first receiver is correlated with that of the second. This correlated information is efficiently transmitted via joint source-channel coding, using ideas similar to the Han-Costa coding scheme. Using the result, we obtain an achievable rate region for the stochastically degraded AWGN broadcast channel with noisy feedback from only one receiver. It is shown that this region is strictly larger than the no-feedback capacity region.Comment: To appear in IEEE Transactions on Information Theory. Contains example of AWGN Broadcast Channel with noisy feedbac

    Progressive damage analysis of CFRP Laminate with circular cutouts under flexural loading

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    Application of a flexural or bending load on a Carbon fiber reinforced polymer(CFRP) specimen leads to both tensile and compressive stress state across the thickness of the specimen thereby resulting in a more complex damage behavior as the tensile and compressive failure modes of a composite material are different. Study of damage behavior of specimen includes location of damage initiation, damage propagation, various types damage modes and their interactions, prediction of damage initiation load and final failure load. Damage behavior of the CFRP specimen has to be studied for its efficient and sustainable design. In the present thesis, damage behavior of pristine CFRP specimen (without hole), specimen with both single circular hole and multiple circular holes having three different configurations (two hole longitudinal (2HL), two hole transverse (2HT) and two hole diagonal (2HD)) was studied both experimentally and numerically under four point flexural loading. The layup sequence of the CFRP specimen having Unidirectional (UD) [0]16 and Quasi-isotropic [−45/0/45/90]2s are studied. Two-dimensional Digital Image correlation(DIC) technique was employed for capturing the in-plane displacement and strains across the thickness of the specimen. Finite element (FE) based Progressive damage analysis(PDA) the CFRP specimen was performed. In the progressive damage model, Hashin’s failure criteria was implemented for the prediction of damage initiation of both fiber or matrix at a lamina level, material property degradation model was implemented for modelling damage evolution in the specimen and cohesive zone model was implemented for predicting the intiation and propagation of interlaminar delamination between layers of the specimen. Damage behavior of the specimen obtained from experiment was compared with the results obtained from PDM for validation. Additionally, the variation of load vs displacement, longitudinal strain distribution over the thickness face of the CFRP specimen obtained both experimentally and numerically were studied and the corresponding plots obtained from both were compared.Finally, the load carrying capacity of pristine specimen, specimen with single hole and specimen with multiple holes with three different configurations (2HL,2HT and 2HD) were compared and it was also seen which type of specimen according to the two lay up sequences which are unidirectional [0]16 and Quasi [−45/0/45/90]2s was more stiffer and stronge

    Boolean Functions with Biased Inputs: Approximation and Noise Sensitivity

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    This paper considers the problem of approximating a Boolean function ff using another Boolean function from a specified class. Two classes of approximating functions are considered: kk-juntas, and linear Boolean functions. The nn input bits of the function are assumed to be independently drawn from a distribution that may be biased. The quality of approximation is measured by the mismatch probability between ff and the approximating function gg. For each class, the optimal approximation and the associated mismatch probability is characterized in terms of the biased Fourier expansion of ff. The technique used to analyze the mismatch probability also yields an expression for the noise sensitivity of ff in terms of the biased Fourier coefficients, under a general i.i.d. input perturbation model.Comment: 5 pages, 2 figures, To appear in IEEE ISIT 201

    Electronic Health Records and Cloud based Generic Medical Equipment Interface

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    Now-a-days Health Care industry is well equipped with Medical Equipments to provide accurate and timely reports of investigation and examination results. Medical Equipments available in market are made for specific tests suited for a particular laboratory leading to a wide variety of devices. The result viewing experience on console of these devices is not only cumborsome for medical staff but inefficient. Therefore, Medical Equipment Interfaces act as backbone of any Hospital Management Information System assisting in better management and delivery of test results. It also acts as a mode to collect data for further research and analysis. These equipments communicate via a fixed data format but compatibility among these formats is a major issue being faced in modern and legacy medical equipments. In this paper, we present a case study of designing and implementing a cloud based Generic Medical Equipment Interface(GMEI) along with the state of the art in such systems. This solution removes the burden of reentry of patient details into the Electronic Health Record(EHR) and thrives for accelerating EMR initiative in the countryComment: National Conference on Medical Informatics 2014 (AIIMS, New Delhi

    Increases in salience of ethnic identity at work: the roles of ethnic assignation and ethnic identification

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    To better understand how ethnicity is actually experienced within organisations, we examined reported increases in ethnic identity salience at work and responses to such increases. Thirty British black Caribbean graduate employees were interviewed about how and when they experienced their ethnic identity at work. The findings demonstrated that increased salience in ethnic identity was experienced in two key ways: through ‘ethnic assignation’ (a ‘push’ towards ethnic identity) and ‘ethnic identification’ (a ‘pull’ towards ethnic identity). We explore how and when ethnic assignation and ethnic identification occur at work, and their relevance to how workplaces are experienced by this group of minority ethnic employees. The findings suggest the need for further research attention to the dynamic and episodic nature of social identity, including ethnic identity, within organisations, and to the impact of such increases in salience of social identities on behaviour at work

    Self-examination for breast and testicular cancers: a community-based intervention study.

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    The prevalence of cancers is growing rapidly in all parts of the word and Pakistan is no exception. Prevention is the best option to tackle this rising epidemic and screening, early detection and health awareness programs are cornerstones in this regard. A community-based interventional study was therefore her conducted to assess the effect of health education intervention about knowledge and practice of self-breast examination (SBE) among women and self-testicular examination (STE) among men. A total of 127 (70 females and 57 males) adults (\u3eor=18 years) from an urban community of Karachi, Pakistan were included after giving informed consent. Interventions were in the local language (Urdu) and included educational and awareness sessions by symposia, lectures and hand-on practice demonstrations about SBE and STE. Informative leaflets and brochure were also employed. Pre-intervention assessment revealed that 57% women had knowledge of SBE and 4% men knew about STE and this proportion increased significantly (

    Modeling Of Fatigue Crack Growth in Composite Repair by Finite Element Method

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    Fatigue failure is caused due to fluctuating loads and is one of the most common type of failure in mechanical structures. Fatigue damage starts with nucleation, crack formation and then propagation of the crack. Estimation of safe life of critical components becomes very essential in fail safe tolerant design for certification. Total life of a component generally consists of two stages viz. crack initiation and crack propagation. The proportion which each contributes will vary with the geometry, the loading and especially with the material. Crack growth behaviour is a major issue in scheduling of inspection and maintenance in variety of industries especially in aircraft industry. Here, failure leads to catastrophic consequences and loss of life. When aircraft reach the end of their service life, fatigue cracks are found to have developed along rivet holes and other highly stressed regions of the aircraft. In order to extend the life of these aircraft, repairs are made to arrest these cracks. This is because huge financial costs involved in manufacturing of aircrafts. Hence, extending the life of in-service aircrafts can provide huge savin
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