35 research outputs found
Fetal QRS complex Detection Algorithm for FPGA Implementation
An algorithm has been developed for the
simultaneous measurement of the fetal and maternal
heart rates from the maternal abdominal
electrocardiogram during pregnancy and labor for
fetal monitoring. The algorithm is based on crosscorrelation, adaptive thresholding and statistical
properties in the time domain. Hardware description
language - VHDL has been used to implement the
algorithm for FPGA implementation. The design is
synthesized and fitted into Altera’s Stratix EP1S10
using the Quartus II platform. Test case results showed
an error percentage of around ±0.3% and ±0.5% for
the detection of maternal and fetal heart rate
respectively
Rank-based model selection for multiple ions quantum tomography
The statistical analysis of measurement data has become a key component of
many quantum engineering experiments. As standard full state tomography becomes
unfeasible for large dimensional quantum systems, one needs to exploit prior
information and the "sparsity" properties of the experimental state in order to
reduce the dimensionality of the estimation problem. In this paper we propose
model selection as a general principle for finding the simplest, or most
parsimonious explanation of the data, by fitting different models and choosing
the estimator with the best trade-off between likelihood fit and model
complexity. We apply two well established model selection methods -- the Akaike
information criterion (AIC) and the Bayesian information criterion (BIC) -- to
models consising of states of fixed rank and datasets such as are currently
produced in multiple ions experiments. We test the performance of AIC and BIC
on randomly chosen low rank states of 4 ions, and study the dependence of the
selected rank with the number of measurement repetitions for one ion states. We
then apply the methods to real data from a 4 ions experiment aimed at creating
a Smolin state of rank 4. The two methods indicate that the optimal model for
describing the data lies between ranks 6 and 9, and the Pearson test
is applied to validate this conclusion. Additionally we find that the mean
square error of the maximum likelihood estimator for pure states is close to
that of the optimal over all possible measurements.Comment: 24 pages, 6 figures, 3 table
Evaluating Temporal Factors in Combined Interventions of Workforce Shift and School Closure for Mitigating the Spread of Influenza
10.1371/journal.pone.0032203PLoS ONE7
Comparability of Results from Pair and Classical Model Formulations for Different Sexually Transmitted Infections
The “classical model” for sexually transmitted infections treats partnerships as instantaneous events summarized by partner change rates, while individual-based and pair models explicitly account for time within partnerships and gaps between partnerships. We compared predictions from the classical and pair models over a range of partnership and gap combinations. While the former predicted similar or marginally higher prevalence at the shortest partnership lengths, the latter predicted self-sustaining transmission for gonorrhoea (GC) and Chlamydia (CT) over much broader partnership and gap combinations. Predictions on the critical level of condom use (Cc) required to prevent transmission also differed substantially when using the same parameters. When calibrated to give the same disease prevalence as the pair model by adjusting the infectious duration for GC and CT, and by adjusting transmission probabilities for HIV, the classical model then predicted much higher Cc values for GC and CT, while Cc predictions for HIV were fairly close. In conclusion, the two approaches give different predictions over potentially important combinations of partnership and gap lengths. Assuming that it is more correct to explicitly model partnerships and gaps, then pair or individual-based models may be needed for GC and CT since model calibration does not resolve the differences
Women on boards of Malaysian firms: Impact on market and accounting performance
We seek to offer some reconciliation for the conflicting theoretical arguments and empirical findings regarding the impact of women’s participation in boards on firms’ performance.We suggest that this impact differs in relation to market- and accounting-performance, and it is firm-specific, and varies by firms’ ownership type and the composition of their boards.These arguments find theoretical underpinnings in agency and resource-dependency theories, combined with behavioral and discrimination theories that articulate women behavior in the workplace and market perception of gender equality.The empirical analysis is based on a dataset of 841 publicly-listed firms in Malaysia.The results show positive impact of women’s participation on accounting-performance and negative impact on market-performance, suggesting that women directors create economic value, which is undervalued by the market. We interpret the findings with reference to the perception of women’s role in society and business in Malaysia, and the nature of corporate governance and ownership types prevalent among Malaysian firms.We suggest that the relationships might be context-specific, and hence the desired level of women’s participation varies across countries.We discuss the normative implications of the findings for government authorities considering legislation of gender-quota on boards, and for firms
Development of an efficient algorithm for fetal heart rate detection: a hardware approach
An algorithm has been developed for the simultaneous measurement of the fetal and maternal heart rates from the maternal abdominal electrocardiogram during pregnancy and labor for fetal monitoring. The algorithm is based on cross-correlation, adaptive thresholding and statistical properties in the time domain. The algorithm was initially developed and simulated in Visual C++. Once the functionality is verified, it is then converted in VHDL - hardware description language for FPGA implementation. The design is synthesized and fitted into Altera's Stratix EP1S10 using the Quartus II platform because of its enhanced DSP capability. Test case results showed an error percentage of around ±0.3% and ±0.5% for the detection of maternal and fetal heart rate respectively