494 research outputs found
A Benchmarking Model for Household Water Consumption Based on Adaptive Logic Networks
Household water benchmarking is an important step in evaluating a household's water usage and comparing it with similar house- holds. It can provide an indicator if a household consumes more water than usual during a certain period of time or some households consume more than other similar households in a particular region. This paper proposes a benchmarking model for household water consumption based on Adaptive Logic Networks (ALNs). Real world data collected by a water consumption monitoring system installed in Sosnowiec, Poland and Skiathos, Greece is respectively used to build a model for each city. The results indicate that the developed models can successfully prediction for a particular use purpose
Mathematical analysis and optimal control of an epidemic model with vaccination and different infectivity
This paper aims to explore the complex dynamics and impact of vaccinations on controlling epidemic outbreaks. An epidemic transmission model which considers vaccinations and two different infection statuses with different infectivity is developed. In terms of a dynamic analysis, we calculate the basic reproduction number and control reproduction number and discuss the stability of the disease-free equilibrium. Additionally, a numerical simulation is performed to explore the effects of vaccination rate, immune waning rate and vaccine ineffective rate on the epidemic transmission. Finally, a sensitivity analysis revealed three factors that can influence the threshold: transmission rate, vaccination rate, and the hospitalized rate. In terms of optimal control, the following three time-related control variables are introduced to reconstruct the corresponding control problem: reducing social distance, enhancing vaccination rates, and enhancing the hospitalized rates. Moreover, the characteristic expression of optimal control problem. Four different control combinations are designed, and comparative studies on control effectiveness and cost effectiveness are conducted by numerical simulations. The results showed that Strategy C (including all the three controls) is the most effective strategy to reduce the number of symptomatic infections and Strategy A (including reducing social distance and enhancing vaccination rate) is the most cost-effective among the three strategies
Suppression of Superconductivity by Twin Boundaries in FeSe
Low-temperature scanning tunneling microscopy and spectroscopy are employed
to investigate twin boundaries in stoichiometric FeSe films grown by molecular
beam epitaxy. Twin boundaries can be unambiguously identified by imaging the
90{\deg} change in the orientation of local electronic dimers from Fe site
impurities on either side. Twin boundaries run at approximately 45{\deg} to the
Fe-Fe bond directions, and noticeably suppress the superconducting gap, in
contrast with the recent experimental and theoretical findings in other iron
pnictides. Furthermore, vortices appear to accumulate on twin boundaries,
consistent with the degraded superconductivity there. The variation in
superconductivity is likely caused by the increased Se height in the vicinity
of twin boundaries, providing the first local evidence for the importance of
this height to the mechanism of superconductivity.Comment: 6 pages, 7 figure
Molecular Beam Epitaxy Growth of Superconducting LiFeAs Film on SrTiO3(001) Substrate
The stoichiometric "111" iron-based superconductor, LiFeAs, has attacted
great research interest in recent years. For the first time, we have
successfully grown LiFeAs thin film by molecular beam epitaxy (MBE) on
SrTiO3(001) substrate, and studied the interfacial growth behavior by
reflection high energy electron diffraction (RHEED) and low-temperature
scanning tunneling microscope (LT-STM). The effects of substrate temperature
and Li/Fe flux ratio were investigated. Uniform LiFeAs film as thin as 3
quintuple-layer (QL) is formed. Superconducting gap appears in LiFeAs films
thicker than 4 QL at 4.7 K. When the film is thicker than 13 QL, the
superconducting gap determined by the distance between coherence peaks is about
7 meV, close to the value of bulk material. The ex situ transport measurement
of thick LiFeAs film shows a sharp superconducting transition around 16 K. The
upper critical field, Hc2(0)=13.0 T, is estimated from the temperature
dependent magnetoresistance. The precise thickness and quality control of
LiFeAs film paves the road of growing similar ultrathin iron arsenide films.Comment: 7 pages, 6 figure
Comparative study of discretization methods of microarray data for inferring transcriptional regulatory networks
<p>Abstract</p> <p>Background</p> <p>Microarray data discretization is a basic preprocess for many algorithms of gene regulatory network inference. Some common discretization methods in informatics are used to discretize microarray data. Selection of the discretization method is often arbitrary and no systematic comparison of different discretization has been conducted, in the context of gene regulatory network inference from time series gene expression data.</p> <p>Results</p> <p>In this study, we propose a new discretization method "bikmeans", and compare its performance with four other widely-used discretization methods using different datasets, modeling algorithms and number of intervals. Sensitivities, specificities and total accuracies were calculated and statistical analysis was carried out. Bikmeans method always gave high total accuracies.</p> <p>Conclusions</p> <p>Our results indicate that proper discretization methods can consistently improve gene regulatory network inference independent of network modeling algorithms and datasets. Our new method, bikmeans, resulted in significant better total accuracies than other methods.</p
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