141 research outputs found

    Ensembles of Randomized Time Series Shapelets Provide Improved Accuracy while Reducing Computational Costs

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    Shapelets are discriminative time series subsequences that allow generation of interpretable classification models, which provide faster and generally better classification than the nearest neighbor approach. However, the shapelet discovery process requires the evaluation of all possible subsequences of all time series in the training set, making it extremely computation intensive. Consequently, shapelet discovery for large time series datasets quickly becomes intractable. A number of improvements have been proposed to reduce the training time. These techniques use approximation or discretization and often lead to reduced classification accuracy compared to the exact method. We are proposing the use of ensembles of shapelet-based classifiers obtained using random sampling of the shapelet candidates. Using random sampling reduces the number of evaluated candidates and consequently the required computational cost, while the classification accuracy of the resulting models is also not significantly different than that of the exact algorithm. The combination of randomized classifiers rectifies the inaccuracies of individual models because of the diversity of the solutions. Based on the experiments performed, it is shown that the proposed approach of using an ensemble of inexpensive classifiers provides better classification accuracy compared to the exact method at a significantly lesser computational cost

    Perceived barriers to utilizing maternal and neonatal health services in contracted-out versus government-managed health facilities in the rural districts of Pakistan

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    Background: A number of developing countries have contracted out public health facilities to the Non-Government Organizations (NGOs) in order to improve service utilization. However, there is a paucity of in-depth qualitative information on barriers to access services as a result of contracting from service users’ perspective. The objective of this study was to explore perceived barriers to utilizing Maternal and Neonatal Health (MNH) services, in health facilities contracted out by government to NGO for service provision versus in those which are managed by government (non-contracted). Methods: A community-based qualitative exploratory study was conducted between April to September 2012 at two contracted-out and four matched non-contracted primary healthcare facilities in Thatta and Chitral, rural districts of Pakistan. Using semi-structured guide, the data were collected through thirty-six Focus Group Discussions (FGDs) conducted with mothers and their spouses in the catchment areas of selected facilities. Thematic analysis was performed using NVivo version 10.0 in which themes and sub-themes emerged. Results: Key barriers reported in contracted sites included physical distance, user charges and familial influences. Whereas, poor functionality of health centres was the main barrier for non-contracted sites with other issues being comparatively less salient. Decision-making patterns for participants of both catchments were largely similar. Spouses and mother-in-laws particularly influenced the decision to utilize health facilities. Conclusion: Contracting out of health facility reduces supply side barriers to MNH services for the community served but distance, user charges and low awareness remain significant barriers. Contracting needs to be accompanied by measures for transportation in remote settings, oversight on user fee charges by contractor, and strong community-based behavior change strategies

    Architectures multi-Asip pour turbo récepteur flexible

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    Rapidly evolving wireless standards use modern techniques such as turbo codes, Bit Interleaved coded Modulation (BICM), high order QAM constellation, Signal Space Diversity (SSD), Multi-Input Multi-Output (MIMO) Spatial Multiplexing (SM) and Space Time Codes (STC) with different parameters for reliable high rate data transmissions. Adoption of such techniques in the transmitter can impact the receiver architecture in three ways: (1) the complex processing related to advanced techniques such as turbo codes, encourage to perform iterative processing in the receiver to improve error rate performance (2) to satisfy high throughput requirement for an iterative receiver, parallel processing is mandatory and finally (3) to allow the support of different techniques and parameters imposed, programmable yet high throughput hardware processing elements are required. In this thesis, to address the high throughput requirement with turbo processing, first of all a study of parallelism on turbo decoding is extended for turbo demodulation and turbo equalization. Based on the results acquired from the parallelism study a flexible high throughput heterogeneous multi-ASIP NoC based unified turbo receiver is proposed. The proposed architecture fulfils the target requirements in a way that: (a) Application Specific Instruction-set Processor (ASIP) exploits metric generation level parallelism and implements the required flexibility, (b) throughputs beyond the capacity of single ASIP in a turbo process are achieved through multiple ASIP elements implementing sub-block parallelism and shuffled processing and finally (c) Network on Chip is used to handle communication conflicts during parallel processing of multiple ASIPs. In pursuit to achieve a hardware model of the proposed architecture two ASIPs are conceived where the first one, namely EquASIP, is dedicated for MMSE-IC equalization and provides a flexible solution for multiple MIMO techniques adopted in multiple wireless standards with a capability to work in turbo equalization context. The second ASIP, named as DemASIP, is a flexible demapper which can be used in MIMO or single antenna environment for any modulation till 256-QAM with or without iterative demodulation. Using available TurbASIP and NoC components, the thesis concludes on an FPGA prototype of heterogeneous multi-ASIP NoC based unified turbo receiver which integrates 9 instances of 3 different ASIPs with 2 NoCs.Les normes de communication sans fil, sans cesse en évolution, imposent l'utilisation de techniques modernes telles que les turbocodes, modulation codée à entrelacement bit (BICM), constellation MAQ d'ordre élevé, diversité de constellation (SSD), multiplexage spatial et codage espace-temps multi-antennes (MIMO) avec des paramètres différents pour des transmissions fiables et de haut débit. L'adoption de ces techniques dans l'émetteur peut influencer l'architecture du récepteur de trois façons: (1) les traitement complexes relatifs aux techniques avancées comme les turbocodes, encourage à effectuer un traitement itératif dans le récepteur pour améliorer la performance en termes de taux d'erreur (2) pour satisfaire l'exigence de haut débit avec un récepteur itératif, le recours au parallélisme est obligatoire et enfin (3) pour assurer le support des différentes techniques et paramètres imposées, des processeurs de traitement matériel flexibles, mais aussi de haute performance, sont nécessaires. Dans cette thèse, pour répondre aux besoins de haut débit dans un contexte de traitement itératif, tout d'abord une étude de parallélisme sur le turbo décodage a été étendue aux applications de turbo démodulation et turbo égalisation. Partant des résultats obtenus à partir de l'étude du parallélisme, un récepteur itératif unifié basé sur un modèle d'architecture multi-ASIP hétérogène intégrant un réseau sur puce (NoC) a été proposé. L'architecture proposée répond aux exigences visées d'une manière où: (a) le concept de processeur à jeu d'instruction dédié à l'application (ASIP) exploite le parallélisme du niveau de génération de métriques et met en oeuvre la flexibilité nécessaire, (b) les débits au-delà de la capacité d'un seul ASIP dans un processus itératif sont obtenus au moyen de multiples ASIP implémentant le parallélisme de sous-blocs et le traitement combiné et enfin (c) le concept de réseau sur puce (NoC) est utilisé pour gérer les conflits de communication au cours du traitement parallèle itératif multi-ASIP. Dans le but de parvenir à un modèle matériel de l'architecture proposée, deux ASIP ont été conçus où le premier, nommé EquASIP, est dédié à l'égalisation MMSE-IC et fournit une solution flexible pour de multiples techniques multi-antennes adoptés dans plusieurs normes sans fil avec la capacité de travailler dans un contexte de turbo égalisation. Le deuxième ASIP, nommé DemASIP, est un démappeur flexible qui peut être utilisé dans un environnement multi-antennes et pour tout type de modulation jusqu'à MAQ-256 avec ou sans démodulation itérative. En intégrant ces ASIP, en plus des NoC et TurbASIP disponibles à Télécom Bretagne, la thèse conclut sur un prototype FPGA d'un récepteur itératif unifié multi-ASIP qui intègre 9 coeurs de 3 différents types d'ASIP avec 2 NoC

    Perceived barriers to utilizing maternal and neonatal health services in contracted-out versus government-managed health facilities in the rural districts of Pakistan

    Get PDF
    Background: A number of developing countries have contracted out public health facilities to the Non-Government Organizations (NGOs) in order to improve service utilization. However, there is a paucity of in-depth qualitative information on barriers to access services as a result of contracting from service users’ perspective. The objective of this study was to explore perceived barriers to utilizing Maternal and Neonatal Health (MNH) services, in health facilities contracted out by government to NGO for service provision versus in those which are managed by government (non-contracted). Methods: A community-based qualitative exploratory study was conducted between April to September 2012 at two contracted-out and four matched non-contracted primary healthcare facilities in Thatta and Chitral, rural districts of Pakistan. Using semi-structured guide, the data were collected through thirty-six Focus Group Discussions (FGDs) conducted with mothers and their spouses in the catchment areas of selected facilities. Thematic analysis was performed using NVivo version 10.0 in which themes and sub-themes emerged. Results: Key barriers reported in contracted sites included physical distance, user charges and familial influences. Whereas, poor functionality of health centres was the main barrier for non-contracted sites with other issues being comparatively less salient. Decision-making patterns for participants of both catchments were largely similar. Spouses and mother-in-laws particularly influenced the decision to utilize health facilities. Conclusion: Contracting out of health facility reduces supply side barriers to MNH services for the community served but distance, user charges and low awareness remain significant barriers. Contracting needs to be accompanied by measures for transportation in remote settings, oversight on user fee charges by contractor, and strong community- based behavior change strategies

    Assessing the Determinants of Savings in Pakistan: An Evidence from PSLM 2010-11

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    The present study aims at investigating the determinants of the savings in Pakistan by using Pakistan Social and Living Standards Measurement (PSLM) survey data collected by Pakistan Bureau of Statistics (PBS) for the year 2010-11. The Multiple Regression Model is estimated for finding out the household saving determinants. The results reveal that savings have positive relationship with income, livestock, number of earner, while these are negatively related with education, gender of the household head and poverty in Pakistan. The regional level analysis reveals that marginal propensity to save is higher in rural areas as compared to urban counterpart. Among the provinces it is the highest in Punjab and lowest in Sindh. To promote savings among households in Pakistan, policies aiming at increasing income of the people should be formulated and implemented. Other policies include creation of job opportunities and provision of loan for livestock especially for the poor and females

    Characterization based machine learning modeling for the prediction of the rheological properties of water‑based drilling mud

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    The successful drilling operation depends upon the achievement of target drilling attributes within the environmental and economic constraints but this is not possible only on the basis of laboratory testing due to the limitation of time and resources. The chemistry of the mud decides its rheological potential and selection of the techniques required for recycling operations. Conductivity, pH, and photometer testing were performed for the physio-chemical characterization of the grass to be used as an environmental friendly drilling mud additive. In this study, different particle sizes (75, 150, and 300 µm) of grass powder were mixed in mud density of 8.5, 8.6, and 8.7 ppg in the measurement of gel strength and viscosity of drilling mud. The grass additive was added in different weight conditions considering no additive, 0.25, 0.5, and 1 g to assess the contribution of grass on the gel strength and viscosity of the drilling mud. The machine learning techniques (Multivariate Linear Regression Analysis, Artificial Neural Network, Support Vector Machine Regression, k-Nearest Neighbor, Decision Stump, Random Forest, and Random Tree approaches) were applied to the generated rheological data. The results of the study show that grass can be used for the improvement of the gel strength and viscosity of the drilling mud. The highest improvement of the viscosity was seen when grass powder of 150 µm was added in the 8.7 ppg drilling mud in 0.25, 0.5, and 1 g weights. The gel strength of the drilling mud was improved when the grass additive was added to the drilling mud 8.7 ppg. Random forest and Artificial Neural Network had the same results of 0.72 regression coefficient (R2) for the estimation of viscosity of the drilling mud. The random tree was found as the most effective technique for the modeling of gel strength at 10 min (GS_10min) of the drilling mud. The predictions of Artificial Neural Network had 0.92 R2 against the measured gel strength at 10 s (GS_10sec) of the drilling mud. On average, Artificial Neural Network predicted the rheological properties of the mud with the highest accuracy as compared to other machine learning approaches. The work may serve as a key source to estimate the net effect of grass additives for the improvement of the gel strength and viscosity of the drilling mud without the performance of any large number of laboratory tests.publishedVersio

    Assessing the Determinants of Savings in Pakistan: An Evidence from PSLM 2010-11

    Get PDF
    The present study aims at investigating the determinants of the savings in Pakistan by using Pakistan Social and Living Standards Measurement (PSLM) survey data collected by Pakistan Bureau of Statistics (PBS) for the year 2010-11. The Multiple Regression Model is estimated for finding out the household saving determinants. The results reveal that savings have positive relationship with income, livestock, number of earner, while these are negatively related with education, gender of the household head and poverty in Pakistan. The regional level analysis reveals that marginal propensity to save is higher in rural areas as compared to urban counterpart. Among the provinces it is the highest in Punjab and lowest in Sindh. To promote savings among households in Pakistan, policies aiming at increasing income of the people should be formulated and implemented. Other policies include creation of job opportunities and provision of loan for livestock especially for the poor and females

    Key Features of SARS-CoV-2 and Available Therapies for COVID-19

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    The disease caused by severe acute respiratory syndrome (SARS-CoV2) is highly pathogenic and communicable infection, progressed in Wuhan city of China and then goes viral around the globe. The Genomic investigations exposed that Phylogenetically SARS-CoV2 resembles the other SARS-like bat viruses, therefore bats were also considered as the possible potential reservoir for SARS-CoV2. There are 2 prevalent types of SARS-CoV2, L type (~70%) and S type (~30%).The L strains are considered more infectious and virulent than the ancestral S strain. The positive sense single-stranded RNA genetic material contains 29891 nucleotides which codes for 9860 amino acids. The ORF1a/b is involved in carrying the translation of two (2) polyproteins, pp1a and pp1ab as well as the encoding of 16 NSPs (Non-structural proteins), and the leftover ORFS can bring about the encoding of non-essential and structural proteins. The origination source and transmission to humankinds is still not clear, but the intermediate hosts are supposed to have a significant role in the transfer and emergence of SARS-CoV2 from bats to humans. There is still no approved drug or vaccine available for Covid-19. In the current review, we condense and fairly evaluate the emergence and pathogenicity of SARS-CoV2, SARS-CoV and MERS-CoV. Moreover, we also discuss the treatment and vaccine developments strategies for Covid-19
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