324 research outputs found

    Deep Reinforcement Learning-Assisted Federated Learning for Robust Short-term Utility Demand Forecasting in Electricity Wholesale Markets

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    Short-term load forecasting (STLF) plays a significant role in the operation of electricity trading markets. Considering the growing concern of data privacy, federated learning (FL) is increasingly adopted to train STLF models for utility companies (UCs) in recent research. Inspiringly, in wholesale markets, as it is not realistic for power plants (PPs) to access UCs' data directly, FL is definitely a feasible solution of obtaining an accurate STLF model for PPs. However, due to FL's distributed nature and intense competition among UCs, defects increasingly occur and lead to poor performance of the STLF model, indicating that simply adopting FL is not enough. In this paper, we propose a DRL-assisted FL approach, DEfect-AwaRe federated soft actor-critic (DearFSAC), to robustly train an accurate STLF model for PPs to forecast precise short-term utility electricity demand. Firstly. we design a STLF model based on long short-term memory (LSTM) using just historical load data and time data. Furthermore, considering the uncertainty of defects occurrence, a deep reinforcement learning (DRL) algorithm is adopted to assist FL by alleviating model degradation caused by defects. In addition, for faster convergence of FL training, an auto-encoder is designed for both dimension reduction and quality evaluation of uploaded models. In the simulations, we validate our approach on real data of Helsinki's UCs in 2019. The results show that DearFSAC outperforms all the other approaches no matter if defects occur or not

    Interactive Free-Viewpoint Video Generation

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    Background Free-viewpoint video (FVV) is processed video content in which viewers can freely select the viewing position and angle. FVV delivers an improved visual experience and can also help synthesize special effects and virtual reality content. In this paper, a complete FVV system is proposed to interactively control the viewpoints of video relay programs through multimedia terminals such as computers and tablets. Methods The hardware of the FVV generation system is a set of synchronously controlled cameras, and the software generates videos in novel viewpoints from the captured video using view interpolation. The interactive interface is designed to visualize the generated video in novel viewpoints and enable the viewpoint to be changed interactively. Results Experiments show that our system can synthesize plausible videos in intermediate viewpoints with a view range of up to 180°

    A Conceptual Framework for Mapping Quantitative Trait Loci Regulating Ontogenetic Allometry

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    Although ontogenetic changes in body shape and its associated allometry has been studied for over a century, essentially nothing is known about their underlying genetic and developmental mechanisms. One of the reasons for this ignorance is the unavailability of a conceptual framework to formulate the experimental design for data collection and statistical models for data analyses. We developed a framework model for unraveling the genetic machinery for ontogenetic changes of allometry. The model incorporates the mathematical aspects of ontogenetic growth and allometry into a maximum likelihood framework for quantitative trait locus (QTL) mapping. As a quantitative platform, the model allows for the testing of a number of biologically meaningful hypotheses to explore the pleiotropic basis of the QTL that regulate ontogeny and allometry. Simulation studies and real data analysis of a live example in soybean have been performed to investigate the statistical behavior of the model and validate its practical utilization. The statistical model proposed will help to study the genetic architecture of complex phenotypes and, therefore, gain better insights into the mechanistic regulation for developmental patterns and processes in organisms

    FaceScape: 3D Facial Dataset and Benchmark for Single-View 3D Face Reconstruction

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    In this paper, we present a large-scale detailed 3D face dataset, FaceScape, and the corresponding benchmark to evaluate single-view facial 3D reconstruction. By training on FaceScape data, a novel algorithm is proposed to predict elaborate riggable 3D face models from a single image input. FaceScape dataset provides 18,760 textured 3D faces, captured from 938 subjects and each with 20 specific expressions. The 3D models contain the pore-level facial geometry that is also processed to be topologically uniformed. These fine 3D facial models can be represented as a 3D morphable model for rough shapes and displacement maps for detailed geometry. Taking advantage of the large-scale and high-accuracy dataset, a novel algorithm is further proposed to learn the expression-specific dynamic details using a deep neural network. The learned relationship serves as the foundation of our 3D face prediction system from a single image input. Different than the previous methods, our predicted 3D models are riggable with highly detailed geometry under different expressions. We also use FaceScape data to generate the in-the-wild and in-the-lab benchmark to evaluate recent methods of single-view face reconstruction. The accuracy is reported and analyzed on the dimensions of camera pose and focal length, which provides a faithful and comprehensive evaluation and reveals new challenges. The unprecedented dataset, benchmark, and code have been released to the public for research purpose.Comment: 14 pages, 13 figures, journal extension of FaceScape(CVPR 2020). arXiv admin note: substantial text overlap with arXiv:2003.1398

    A retrospective study on the physical growth of twins in the first year after birth

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    ObjectivesThis study analyzed the physical growth of small for gestational age (SGA) and appropriate for gestational age (AGA) twins up to one year after birth.MethodsWeight, length, and head circumference data of 0–1 year-old twins were collected from the Child Health Care System from 2010 to 2019. Physical data were presented as Z-scores. Five parameters – growth level of weight, body length, head circumference, growth velocity, and body proportion (weight for length) were compared in twins.ResultsA total of 3,909 cases were collected (22.61% SGA, 77.39% AGA). 1. In both groups, WAZ (Weight for age z-score), HCZ (Head circumference for age z-score), and LAZ (Length for age z-score) increased more rapidly in the first 6 months. By one year of age, WAZ, HCZ, and LAZ had reached the normal range, but none had reached the average level of normal singleton children. 2. The mean values of WAZ, HCZ, and LAZ in the AGA group were between −1 and 0, and between −2 and − 1 in the SGA group, in the first year after birth. The SGA group lagged significantly behind the AGA group. The LAZ score of SGA and AGA was lower than the WAZ and HCZ scores. 3. The proportion of preterm AGA was the largest in twins, and the growth rate of preterm AGA was the fastest. Preterm twins had greater growth potential than term twins. However, the growth level of preterm SGA was always low. 4. The WFLZ (Weight for length z-score) in each group was approximately close to 0. The WFLZ of SGA was smaller than that of AGA twins at most time points. After 4 months of age, the WFLZ of twins had a downward trend. The WFLZ of preterm SGA approached −1 at approximately 1 year old.ConclusionThe physical growth of SGA and AGA in twins in the first year can reach the normal range but cannot reach the average level of normal singleton children. More attention should be paid to SGA in twins, especially preterm SGA. We should give proper nutritional guidance after 4 months of age to ensure the appropriate body proportion (weight for length) of SGA in twins.Clinical trial registrationwww.chictr.org.cn, CTR2000034761

    Experiments on bright field and dark field high energy electron imaging with thick target material

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    Using a high energy electron beam for the imaging of high density matter with both high spatial-temporal and areal density resolution under extreme states of temperature and pressure is one of the critical challenges in high energy density physics . When a charged particle beam passes through an opaque target, the beam will be scattered with a distribution that depends on the thickness of the material. By collecting the scattered beam either near or off axis, so-called bright field or dark field images can be obtained. Here we report on an electron radiography experiment using 45 MeV electrons from an S-band photo-injector, where scattered electrons, after interacting with a sample, are collected and imaged by a quadrupole imaging system. We achieved a few micrometers (about 4 micrometers) spatial resolution and about 10 micrometers thickness resolution for a silicon target of 300-600 micron thickness. With addition of dark field images that are captured by selecting electrons with large scattering angle, we show that more useful information in determining external details such as outlines, boundaries and defects can be obtained.Comment: 7pages, 7 figure

    Prevalence and genotype distribution of HPV infection among women in Xiamen, China

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    ObjectiveThis study aimed to evaluate the prevalence of HPV and genotype distribution among female populations in Xiamen, Fujian Province, China, which can be conducive for local governments to formulate cervical cancer screening and HPV vaccine strategies.MethodsCervical swabs were collected from 47,926 participants aged 16–92 years at the Women and Children’s Hospital, Xiamen University, from November 2019 to June 2020. HPV DNA was extracted and detected using conventional PCR, followed by HPV subtype-specific hybridisation. HPV infection rates based on different groups were compared using the χ2 test. HPV prevalence and the corresponding 95% confidence intervals (95% CI) were calculated using SPSS 19.0.ResultsThe overall HPV prevalence among the 47,926 cervical swabs that were analysed was 15.13%, of which single, double, and multiple infections accounted for 76.83, 16.70 and 6.47%, respectively. The age-specific prevalence of HPV infection presented a “U” curve with a HPV prevalence peak observed in women aged <20 years. The gynaecology clinic group had significantly higher HPV positive rates than the health examination group (p < 0.001). The five most common HR-HPV subtypes in Xiamen were HPV52, 58, 16, 51, and 39 (2.69, 1.63, 1.23, 1.05, and 0.98%, respectively). The five most common LR-HPV subtypes were HPV54, 61, 81, 70, 34, and 84 (0.92, 0.86, 0.71, 0.45 and 0.35%, respectively).ConclusionOur findings demonstrate that the 9-valent HPV vaccine is recommended for regular immunisation in Xiamen. It is necessary for elderly women to participate in HPV screening to decrease the morbidity and mortality of cervical cancer

    Preparation of Pullulan Polysaccharide/Thermoplastic Polyurethane Coaxial Electrospinning Film with Oregano Essential Oil as Core Material and Its Preservative Effect on the Quality of Lateolabrax japonicus Fillets

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    The use of plant essential oils as an antibacterial agent for food packaging has become a new trend. In order to obtain biodegradable films for the preservation of aquatic products, coaxial electrospinning films were prepared by electrospinning using the antimicrobial preservative oregano essential oil (OEO) or its main components as core material, pullulan (Pul) as film-forming substrate, and thermoplastic polyurethane (TPU) as shell material and were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy. Also, its thermal stability, physicochemical properties was determined as well as the release performance of the antimicrobial preservative from the coaxial electrospinning films and its efficacy in preserving the quality of refrigerated Lateolabrax japonicus fillets. The results showed that OEO was effectively encapsulated in the electrospinning fibers, improving the micromorphology, water vapor barrier properties and wettability and significantly reducing the tensile strength (TS), and swelling degree (SD) of the film (P < 0.05), but not changing the thermal stability of the film significantly. The fibers inside the film had a coaxial core-shell structure, and the release behavior of the preservative was a complex coupling of disintegration and dissolution, resulting in controlled OEO release for up to 60 h. In addition, the film effectively inhibited the growth of microorganisms, and thus had excellent preservative effect on fresh L. japonicus fillets. It effectively delayed the deterioration of the smell, texture and apparent quality of the fillets, and extended the shelf life from 8 to 12 d. This study can provide a theoretical basis and technical support for the development of biodegradable antibacterial packaging materials based on biological antibacterial agents
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