839 research outputs found

    Optimizing FPGA-based CNN accelerator for energy efficiency with an extended Rooine model

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    In recent years, the convolutional neural network (CNN) has found wide acceptance in solving practical computer vision and image recognition problems. Also recently, due to its exibility, faster development time, and energy efficiency, the field-programmable gate array (FPGA) has become an attractive solution to exploit the inherent parallelism in the feedforward process of the CNN. However, to meet the demands for high accuracy of today's practical recognition applications that typically have massive datasets, the sizes of CNNs have to be larger and deeper. Enlargement of the CNN aggravates the problem of off-chip memory bottleneck in the FPGA platform since there is not enough space to save large datasets on-chip. In this work, we propose a memory system architecture that best matches the off-chip memory traffic with the optimum throughput of the computation engine, while it operates at the maximum allowable frequency. With the help of an extended version of the Rooine model proposed in this work, we can estimate memory bandwidth utilization of the system at different operating frequencies since the proposed model considers operating frequency in addition to bandwidth utilization and throughput. In order to find the optimal solution that has the best energy efficiency, we make a trade-off between energy efficiency and computational throughput. This solution saves 18% of energy utilization with the trade-off having less than 2% reduction in throughput performance. We also propose to use a race-to-halt strategy to further improve the energy efficiency of the designed CNN accelerator. Experimental results show that our CNN accelerator can achieve a peak performance of 52.11 GFLOPS and energy efficiency of 10.02 GFLOPS/W on a ZYNQ ZC706 FPGA board running at 250 MHz, which outperforms most previous approaches

    Morphological characteristics of black aspergilli isolated from clinical wastes

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    The present study aimed to recognize the microscopic characteristics of black aspergilli species which exhibit similar characteristics on culture media. Forty eight black aspergilli isolates were obtained from clinical wastes and purified using single spore technique on six different culture media. The ultrastructure of fungal conidiophore and spores was detected by using Scanning Electron Microscope (SEM). The fungal isolates were identified within five species included A. niger, A. tubingensis, Aspergillus section Nigri, A. violaceofuscus, A. neoniger. Besides, two isolates identified as Aspergillus sp. strain no. 39, Aspergillus sp. strain no. 53 appear as new strains based on the structure of conidiophore and spores. The fungi species have similar culture characteristics. However, SEM observation demonstrated that they have quite different conidiophore and spores morphology. The study revealed that the microstructure of the fungal spores and conidiophores plays an important role in the identification of fungi species based on the phenotypic method

    Techniques for extraction of bioactive compounds from plant materials: a review

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    The use of bioactive compounds in different commercial sectors such as pharmaceutical, food and chemical industries signifies the need of the most appropriate and standard method to extract these active components from plant materials. Along with conventional methods, numerous new methods have been established but till now no single method is regarded as standard for extracting bioactive compounds from plants. The efficiencies of conventional and non conventional extraction methods mostly depend on the critical input parameters; understanding the nature of plant matrix; chemistry of bioactive compounds and scientific expertise. This review is aimed to discuss different extraction techniques along with their basic mechanism for extracting bioactive compounds from medicinal plant

    Performance Evaluation of Centralized Reconfigurable Transmitting Power Scheme in Wireless Network-on-chip

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    Network-on-chip (NoC) is an on-chip communication network that allows parallel communication among all cores to improve inter-core performance. Wireless NoC (WiNoC) introduces long-range and high bandwidth radio frequency (RF) interconnects that can possibly reduce the multi-hop communication of the planar metal interconnects in conventional NoC platforms. In WiNoC, RF transceivers account for a significant power consumption, particularly its transmitter, out of its total communication energy. This paper evaluates the energy and latency performance of a closed loop power management mechanism which enables transmitting power reconfiguration in WiNoC based on number of erroneous received packets. The scheme achieves significant energy savings with limited performance degradation and insignificant impact on throughput

    Survey of women's report for 33 maternal and newborn indicators: EN-BIRTH multi-country validation study.

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    BACKGROUND: Population-based household surveys, notably the Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS), remain the main source of maternal and newborn health data for many low- and middle-income countries. As part of the Every Newborn Birth Indicators Research Tracking in Hospitals (EN-BIRTH) study, this paper focuses on testing validity of measurement of maternal and newborn indicators around the time of birth (intrapartum and postnatal) in survey-report. METHODS: EN-BIRTH was an observational study testing the validity of measurement for selected maternal and newborn indicators in five secondary/tertiary hospitals in Bangladesh, Nepal and Tanzania, conducted from July 2017 to July 2018. We compared women's report at exit survey with the gold standard of direct observation or verification from clinical records for women with vaginal births. Population-level validity was assessed by validity ratios (survey-reported coverage: observer-assessed coverage). Individual-level accuracy was assessed by sensitivity, specificity and percent agreement. We tested indicators already in DHS/MICS as well as indicators with potential to be included in population-based surveys, notably the first validation for small and sick newborn care indicators. RESULTS: 33 maternal and newborn indicators were evaluated. Amongst nine indicators already present in DHS/MICS, validity ratios for baby dried or wiped, birthweight measured, low birthweight, and sex of baby (female) were between 0.90-1.10. Instrumental birth, skin-to-skin contact, and early initiation of breastfeeding were highly overestimated by survey-report (2.04-4.83) while umbilical cord care indicators were massively underestimated (0.14-0.22). Amongst 24 indicators not currently in DHS/MICS, two newborn contact indicators (kangaroo mother care 1.00, admission to neonatal unit 1.01) had high survey-reported coverage amongst admitted newborns and high sensitivity. The remaining indicators did not perform well and some had very high "don't know" responses. CONCLUSIONS: Our study revealed low validity for collecting many maternal and newborn indicators through an exit survey instrument, even with short recall periods among women with vaginal births. Household surveys are already at risk of overload, and some specific clinical care indicators do not perform well and may be under-powered. Given that approximately 80% of births worldwide occur in facilities, routine registers should also be explored to track coverage of key maternal and newborn health interventions, particularly for clinical care

    Wheat is an emerging exposure route for arsenic in Bihar, India

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    In arsenic (As) endemic areas of south-east Asia, where a subsistence rice-based diet is 19 prevalent, As exposure from food is mainly focused on rice intake. However, consumption of 20 wheat is substantial and increasing. We present a probabilistic assessment of increased cancer 21 risk from wheat-based food intake in a study population of rural Bihar, India where As exposure 22 is endemic. Total As in wheat grains (43.64±48.19 μg/kg, n=72) collected from 77 households 23 across 19 villages was found to be lower than reported As in wheat grains from other south-24 east Asian countries but higher than a previous study from Bihar. As concentration in wheat flour was used for risk estimation, bearing in mind that it was the 26 flour obtained after indigenous household processing of the grains that was used for making 27 the home-made bread (chapati) which contributed 95% of wheat intake for the studied 28 population. Interestingly, while 78% of the surveyed participants (n=154) consumed rice every 29 day, chapati was consumed every day by 99.5% of the participants. In contrast to previous 30 studies, where As concentration in wheat grain was found to be lower than the flour due to the 31 removal of the bran on grinding, we did not find any appreciable lowering of arsenic in the 32 wheat flour (49.80±74.08 μg/kg, n=58), most likely due to external contamination during 33 processing and grinding. Estimated gender adjusted excess lifetime cancer risk of 1.23x10-4 for 34 the studied rural population of Bihar indicated risk higher than the 10-4-10-6 range, typically 35 used by the USEPA as a threshold to guide regulatory values. Hence, our findings suggest As 36 exposure from wheat-based food intake to be of concern not only in As endemic areas of rural 37 Bihar but also in non-endemic areas with similar wheat-based diet due to public distribution of 38 the wheat across India

    Performance of copper electrode in electical discharge machining (edm) of aisi h13 harden steel

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    ABSTRACT Electrical discharge machining (EDM) is a popular nonconventional machining method for manufacturing geometrically complex or hard materials parts that are extremely difficult to machine by conventional machining. EDM applies the concept of metal removal by using electric spark erosion. This study is carried out to investigate the performance of copper electrode when EDMing AISI H13 tool steel. The parameters considered are the peak current, pulse ON-time, and pulse OFF-time. The effect of peak current settings (1, 2 and 4 A), pulse-ON time (3, 6 and 12 Ps) and pulse-OFF time (1, 2 and 4 Ps) were investigated on the machining performance of the surface roughness (R a ), electrode wear rate (EWR) and material removal rate (MRR). Results showed that the optimum condition for surface roughness was obtained at low peak current, low pulse-ON and pulse-OFF time. Whereas, high MRR was obtained when setting at high peak current, medium pulse-ON time, and low pulse-OFF time. Therefore the peak current was the major factor affecting the MRR and surface finish both for finishing and roughing operations. The 'no wear' situation for EWR was obtained at high peak current, high pulse-ON time, and low pulse-OFF time

    Influence of the initial chemical conditions on the rational design of silica particles

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    The influence of the water content in the initial composition on the size of silica particles produced using the Stöber process is well known. We have shown that there are three morphological regimes defined by compositional boundaries. At low water levels (below stoichiometric ratio of water:tetraethoxysilane), very high surface area and aggregated structures are formed; at high water content (>40 wt%) similar structures are also seen. Between these two boundary conditions, discrete particles are formed whose size are dictated by the water content. Within the compositional regime that enables the classical Stöber silica, the structural evolution shows a more rapid attainment of final particle size than the rate of formation of silica supporting the monomer addition hypothesis. The clearer understanding of the role of the initial composition on the output of this synthesis method will be of considerable use for the establishment of reliable reproducible silica production for future industrial adoption

    Adolescent to Adolescent Transformation Program- Nurturing, Enhancing and Promoting Adolescents’ Healthy Habit (ATAP-NEPAH): Curbing Social Problems Among Adolescents in Kelantan Through Peer-To-Peer Health Education

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    The objectives of ATAP-NEPAH are to enhance and nurture healthy habits among adolescents as well as to empower adolescents in inculcating these healthy habits among them. Health education through peer-to-peer approach is used to instill the knowledge on important areas such as sexual and reproductive health, smoking, substance abuse, illegal street racing (rempit) and mental health. Specific modules were developed by experts (lecturers) in multidisciplinary fields in collaboration with Malaysian Association for Adolescent Health (MAAH), National Population and Family Development Board (NPFDB), Reproductive Health Association of Kelantan (REHAK) and Rhaudatus Sakinah Kelantan. The trained Medical Students Facilitator Team (MSFT) of USM became trainers to secondary one school students. The selected school students were trained by the medical students to become peer educators to their juniors and peers. There was improvement in the readiness level of peer educators, knowledge and attitude towards healthy habits and risky behaviors of other school students after the intervention

    IL-21 signaling is essential for optimal host resistance against Mycobacterium tuberculosis infection

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    IL-21 is produced predominantly by activated CD4(+) T cells and has pleiotropic effects on immunity via the IL-21 receptor (IL-21R), a member of the common gamma chain (gamma(c)) cytokine receptor family. We show that IL-21 signaling plays a crucial role in T cell responses during Mycobacterium tuberculosis infection by augmenting CD8(+) T cell priming, promoting T cell accumulation in the lungs, and enhancing T cell cytokine production. In the absence of IL-21 signaling, more CD4(+) and CD8(+) T cells in chronically infected mice express the T cell inhibitory molecules PD-1 and TIM-3. We correlate these immune alterations with increased susceptibility of IL-21R(-/-) mice, which have increased lung bacterial burden and earlier mortality compared to WT mice. Finally, to causally link the immune defects with host susceptibility, we use an adoptive transfer model to show that IL-21R(-/-) T cells transfer less protection than WT T cells. These results prove that IL-21 signaling has an intrinsic role in promoting the protective capacity of T cells. Thus, the net effect of IL-21 signaling is to enhance host resistance to M. tuberculosis. These data position IL-21 as a candidate biomarker of resistance to tuberculosis.This work was supported by National Institutes of Health Grants R21 AI100766, R01 AI106725, and P01 AI073748
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