Image Signal Processor parameter tuning with surrogate-assisted Particle Swarm Optimization

International audienceEvolutionary algorithms (EA) are developed and compared based on well defined benchmark problems, but their application to real-world problems is still challenging. In image processing, EA have been used to tune a particular image filter or in the design of filters themselves. But nowadays in digital cameras, the image sensor captures a raw image that is then processed by an Image Signal Processor (ISP) where several transformations or filters are sequentially applied in order to enhance the final picture. Each of these steps have several parameters and their tuning require lot of resources that are usually performed by human experts based on metrics to assess the quality of the final image. This can be considered as an expensive black-box optimization problem with many parameters and many quality metrics. In this paper, we investigate the use of EA in the context of ISP parameter tuning with the aim of raw image enhancement

The sugar content of children’s and lunchbox beverages sold in the UK before and after the soft drink industry levy

Background: Childhood obesity is associated with an increased intake of sugary soft drinks and juice drinks. The aims of this study were (1) to report the sugar and energy content in commercial fruit juice (FJ), juice drinks (JD) and smoothies (S) specifically targeted at children in the UK, (2) to identify beverages liable for the Soft Drinks Industry Levy (SDIL) and (3) to compare the amount of sugar in these beverages before and after the levy. Methods: The beverages were retrieved using the online shopping tool my Supermarket, websites of nine major supermarket in the UK and manufacturers webpages. Comparisons of sugar content were taken before and after the introduction of the SDIL. Results: 131 FJJDS fulfilled the inclusion criteria. The mean sugar content of all the beverages was 6.3g±4.5/100mL. There was large variation in the sugar content from 0.1g/100mL to 15.2g/100mL, with smoothies found to contain the most sugar (11.55±1.62 g/mL). The beverages were reanalysed in September 2018 to determine their eligibility for the SDIL. Of the 131 products only 7 JD were eligible for the levy. Four of these beverages had reformulated their ingredients since the initial analysis resulting in a sugar content of <5g/100mL. Conclusions: The majority of the beverages targeted at children and children’s lunch boxes were not eligible for the SDIL. This study suggests the necessity to adapt the SDIL to include all FJJDS aimed at children as the total sugar content of these beverages are still above the recommended quantities for this age group

Nearly Monodispersion CoSm Alloy Nanoparticles Formed by an In-situ Rapid Cooling and Passivating Microfluidic Process

An in siturapid cooling and passivating microfluidic processhas been developed for the synthesis of nearly monodispersed cobalt samarium nanoparticles (NPs) with tunable crystal structures and surface properties. This process involves promoting the nucleation and growth of NPs at an elevated temperature and rapidly quenching the NP colloids in a solution containing a passivating reagent at a reduced temperature. We have shown that Cobalt samarium NPs having amorphous crystal structures and a thin passivating layer can be synthesized with uniform nonspherical shapes and size of about 4.8 nm. The amorphous CoSm NPs in our study have blocking temperature near 40 K and average coercivity of 225 Oe at 10 K. The NPs also exhibit high anisotropic magnetic properties with a wasp-waist hysteresis loop and a bias shift of coercivity due to the shape anisotropy and the exchange coupling between the core and the thin oxidized surface layer

Bs0−Bˉs0B_s^0-\bar B_s^0 mixing in a family non-universal Z′Z^{\prime} model revisited

Motivated by the very recent measurements performed at the LHCb and the Tevatron of the $B_s^0-\bar B_s^0$ mixing, in this paper we revisit it in a family non-universal $Z^{\prime}$ model, to check if a simultaneous explanation for all the mixing observables, especially for the like-sign dimuon charge asymmetry observed by the D0 collaboration, could be made in such a specific model. In the first scenario where the $Z^\prime$ boson contributes only to the off-diagonal element $M_{12}^s$, it is found that, once the combined constraints from $\Delta M_s$, $\phi_s$ and $\Delta \Gamma_s$ are imposed, the model could not explain the measured flavour-specific CP asymmetry $a_{fs}^s$, at least within its $1\sigma$ ranges. In the second scenario where the NP contributes also to the absorptive part $\Gamma_{12}^s$ via tree-level $Z^\prime$-induced $b\to c\bar{c}s$ operators, we find that, with the constraints from $\Delta M_s$, $\phi_s$ and the indirect CP asymmetry in $\bar{B}_d\to J/\psi K_S$ taken into account, the present measured $1\sigma$ experimental ranges for $a_{fs}^s$ could not be reproduced too. Thus, such a specific $Z^\prime$ model with our specific assumptions could not simultaneously reconcile all the present data on $B_s^0-\bar B_s^0$ mixing. Future improved measurements from the LHCb and the proposed superB experiments, especially of the flavour-specific CP asymmetries, are expected to shed light on the issue.Comment: 30 pages, 6 figures, 1 table, pdflatex; accepted by JHE

Automated inter-rater reliability assessment and electronic data collection in a multi-center breast cancer study

<p>Abstract</p> <p>Background</p> <p>The choice between paper data collection methods and electronic data collection (EDC) methods has become a key question for clinical researchers. There remains a need to examine potential benefits, efficiencies, and innovations associated with an EDC system in a multi-center medical record review study.</p> <p>Methods</p> <p>A computer-based automated menu-driven system with 658 data fields was developed for a cohort study of women aged 65 years or older, diagnosed with invasive histologically confirmed primary breast cancer (N = 1859), at 6 Cancer Research Network sites. Medical record review with direct data entry into the EDC system was implemented. An inter-rater and intra-rater reliability (IRR) system was developed using a modified version of the EDC.</p> <p>Results</p> <p>Automation of EDC accelerated the flow of study information and resulted in an efficient data collection process. Data collection time was reduced by approximately four months compared to the project schedule and funded time available for manuscript preparation increased by 12 months. In addition, an innovative modified version of the EDC permitted an automated evaluation of inter-rater and intra-rater reliability across six data collection sites.</p> <p>Conclusion</p> <p>Automated EDC is a powerful tool for research efficiency and innovation, especially when multiple data collection sites are involved.</p

Evidence for B- -> tau- nu_bar with a Semileptonic Tagging Method

We present a measurement of the decay B- -> tau- nu_bar using a data sample containing 657 million BB_bar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. A sample of BB_bar pairs are tagged by reconstructing one B meson decaying semileptonically. We detect the B- -> tau- nu_bar candidate in the recoil. We obtain a signal with a significance of 3.6 standard deviations including systematic uncertainties, and measure the branching fraction to be Br(B- -> tau- nu_bar) = [1.54+0.38-0.37(stat)+0.29-0.31(syst)]*10^-4. This result confirms the evidence for B- -> tau- nu_bar obtained in a previous Belle measurement that used a hadronic B tagging method.Comment: 7 pages, 3 figures, corrected references, to appear in PRD-R

Synthesis of Monodisperse Nanocrystals via Microreaction: Open-to-Air Synthesis with Oleylamine as a Coligand

Microreaction provides a controllable tool to synthesize CdSe nanocrystals (NCs) in an accelerated fashion. However, the surface traps created during the fast growth usually result in low photoluminescence (PL) efficiency for the formed products. Herein, the reproducible synthesis of highly luminescent CdSe NCs directly in open air was reported, with a microreactor as the controllable reaction tool. Spectra investigation elucidated that applying OLA both in Se and Cd stock solutions could advantageously promote the diffusion between the two precursors, resulting in narrow full-width-at-half maximum (FWHM) of PL (26 nm). Meanwhile, the addition of OLA in the source solution was demonstrated helpful to improve the reactivity of Cd monomer. In this case, the focus of size distribution was accomplished during the early reaction stage. Furthermore, if the volume percentage (vol.%) of OLA in the precursors exceeded a threshold of 37.5%, the resulted CdSe NCs demonstrated long-term fixing of size distribution up to 300 s. The observed phenomena facilitated the preparation of a size series of monodisperse CdSe NCs merely by the variation of residence time. With the volume percentage of OLA as 37.5% in the source solution, a 78 nm tuning of PL spectra (from 507 to 585) was obtained through the variation of residence time from 2 s to 160 s, while maintaining narrow FMWH of PL (26–31 nm) and high QY of PL (35–55%)