140 research outputs found

    EFFL: Egalitarian Fairness in Federated Learning for Mitigating Matthew Effect

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    Recent advances in federated learning (FL) enable collaborative training of machine learning (ML) models from large-scale and widely dispersed clients while protecting their privacy. However, when different clients' datasets are heterogeneous, traditional FL mechanisms produce a global model that does not adequately represent the poorer clients with limited data resources, resulting in lower accuracy and higher bias on their local data. According to the Matthew effect, which describes how the advantaged gain more advantage and the disadvantaged lose more over time, deploying such a global model in client applications may worsen the resource disparity among the clients and harm the principles of social welfare and fairness. To mitigate the Matthew effect, we propose Egalitarian Fairness Federated Learning (EFFL), where egalitarian fairness refers to the global model learned from FL has: (1) equal accuracy among clients; (2) equal decision bias among clients. Besides achieving egalitarian fairness among the clients, EFFL also aims for performance optimality, minimizing the empirical risk loss and the bias for each client; both are essential for any ML model training, whether centralized or decentralized. We formulate EFFL as a constrained multi-constrained multi-objectives optimization (MCMOO) problem, with the decision bias and egalitarian fairness as constraints and the minimization of the empirical risk losses on all clients as multiple objectives to be optimized. We propose a gradient-based three-stage algorithm to obtain the Pareto optimal solutions within the constraint space. Extensive experiments demonstrate that EFFL outperforms other state-of-the-art FL algorithms in achieving a high-performance global model with enhanced egalitarian fairness among all clients

    Temperature-Dependent Anomalies in the Structure of the (001) Surface of LiCu2O2

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    Surface corrugation functions, derived from elastic helium atom scattering (HAS) diffraction patterns at different temperatures, reveal that the Cu2+ rows in the (001) surface of LiCu2O2 undergo an outward displacement of about 0.15 {\AA} as the surface was cooled down to 140 K. This is probably the first time that isolated one-dimensional magnetic ion arrays were realized, which qualifies the Li1+Cu2+O2-2 surface as a candidate to study one-dimensional magnetism. The rising Cu2+ rows induce a surface incommensurate structural transition along the a-direction. Surface equilibrium analysis showed that the surface Cu2+ ions at bulk-like positions experience a net outward force along the surface normal which is relieved by the displacement. Temperature-dependent changes of the surface phonon dispersions obtained with the aid of inelastic HAS measurements combined with surface lattice dynamical calculations are also reported.Comment: 4 pages, 7 figure

    Influence of laser cutting conditions on electrical characteristics of half-size bifacial silicon solar cells

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    Abstract(#br)The half-size bifacial silicon solar cells have garnered significant research attention in photovoltaic (PV) modules because they render enhanced power output. Herein, the influence of cutting surface and scribing iteration times on electrical characteristics of bifacial silicon solar cells is investigated in detail. The results reveal that the cutting process should be carried out from the rear side and scribing iteration times should be twice. Moreover, we have studied the cutting losses of n-type passivated emitter and rear totally diffused (n-PERT) bifacial solar cells and demonstrated that not mechanical breaking but laser scribing is a major source of losses during the cell separation process. In addition, the damage induced by the cut was systematically investigated and it was observed that the heat-affected zone resulted in negligible damage under optimal cutting conditions. Overall, n-PERT half-cell bifacial modules, sectioned under optimal cutting conditions, can maintain high efficiency and excellent reliability

    Preparation and electromechanical properties of PVDF matrix piezo-electric composites containing highly oriented BaTiO3 whiskers

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    The piezoelectric composites containing highly oriented BaTiO3 whiskers as active phase and PVDF as matrix have been prepared by micro-hole extrusion and orientation in carried fibers. The morphology of oriented BaTiO3 whiskers and microstructure of the composites were observed by SEM. As for its electromechanical properties, it is found that the dielectric constant, piezoelectric constant and remnant of polarization in the BaTiO3 whisker-PVDF composite are considerably higher than that in the BaTiO3 powders-PVDF composite, while the loss factors follow the opposite trend. For the BaTiO3 whisker-PVDF composite, the values of epsilon, d(33) and P-r parallel to the whisker orientation (normal specimen) are much higher than that perpendicular to the whisker orientation (parallel specimen). The significant effects of the connective passages of active phase on electromechanical properties of the piezoelectric composites has also been investigated

    Preoperative inflammatory markers predict postoperative clinical outcomes in patients undergoing heart valve surgery: A large-sample retrospective study

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    IntroductionPreoperative inflammation affects the postoperative outcomes of patients undergoing heart valve surgery. This study aimed to explore the role and predictive effects of preoperative inflammation on the primary outcomes after valvular cardiac surgery.MethodsThis retrospective study utilized a medical recording system to screen 5075 patients who underwent heart valve surgery. Data on the C-reactive protein (CRP) levels, erythrocyte sedimentation rate (ESR), and neutrophil-to-lymphocyte ratio (NLR) before heart valve surgery were collected from the hospital’s medical system. Postoperative hepatic insufficiency, acute kidney injury, heart failure, and myocardial damage were assessed using blood indicators. Patients with and without prolonged mechanical ventilation, extended intensive care unit stays, prolonged hospital stays, and death within 30 days after surgery (considered the primary outcome in this study) were compared. Group comparisons, receiver operating characteristic (ROC) curve analyses, and logistic analyses were performed to determine the associations between preoperative inflammation and outcomes after heart valve surgery.ResultsA total of 3249 patients were included in the analysis. Significant differences in CRP level, ESR, and NLR were found between patients with and without postoperative adverse outcomes. ROC analysis showed that CRP levels >5 mg/L effectively predicted postoperative heart failure, and NLR >3.5 had a good predictive effect on all-cause mortality within 30 days after surgery. Patients with CRP levels >5 mg/L had a higher incidence of postoperative heart failure than other patients (20.7% vs. 12.6%, P<0.001), with a relative risk of 1.447 (95% confidence interval: 1.155–1.814). Patients with NLR >3.5 had a higher incidence of death within 30 days after surgery (5.3% vs. 1.2%, P<0.001), with a relative risk of 3.236 (95% confidence interval: 1.773–5.906).ConclusionPreoperative inflammation can affect postoperative outcomes in patients undergoing heart valve surgery. CRP level >5 mg/L and NLR >3.5 can effectively predict postoperative heart failure and death within 30 days after surgery, respectively

    Поліморфізм качок породи shaoxing за мікросателітними локусами

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    Microsatellite markers are now been widely used for the detection and description of micropopulation processes occurring in the populations of domestic animals for the effects of various factors of breeding pressure. Microsatellite loci distributed throughout eukaryotic genomes, making them the preferred genetic marker for high resolution genetic mapping. In recent years, rapid advances have been made in the development of molecular genetic maps. High-density linkage maps are now available for many farm animals, such as cattle, pigs, and goats. In contrast, mapping studies in avian species are much less advanced except in the chicken. According to FAO about 70% of ducks are bred in China. This country is a leader in growing ducks. The Shaoxing breed is one of the three major duck breeds in China. Ducks of this breed are characterized by high performance. According to the Bureau of Product Quality, the age of maturity (the beginning of egg laying) in these birds occurs at 130–140 days. The characteristics of the Shaoxing breed include the fact that the peak period of laying eggs lasts from eight to ten months. On average, one duck in 500 days gives from 290 to 310 eggs, which is one of the highest rates for egg breeds. That is why the purpose of our study was the microsatellite analysis of two populations of Shaoxing breed with 9 locuses was conducted. The selection of birds for the study were carried out on a duck farms in Zhejiang Generation Biological Science and Technology Co., Ltd. and Zhuji Guowei Poultry Development Co, Ltd., and at the laboratory of the Jjejiang Academy of Sciences Institute. Samples collection and  DNA  preparation: Venous blood  samples  were  collected  from 480 ducks (240 ducks of population I and 240 ducks of population II of the Shaoxing breeds)  of  both populations  into  3  ml  tubes  containing  EDTA  as anticoagulant agent. In total of 9 investigated loci in the Shaoxing breed population, only one locus was monomorphic (SMO10). The number of different alleles (Na) for each polymorphic locus ranged from 2 (SMO12) to 13 (APL79, CMO11) in population I and from 2 (APL78, SMO12) to 7 (APL79) in population II. On average, one locus had 5.889 alleles in population I and 3.889 of alleles in the population II. The effective number of alleles (Nе) was 1.735 in population I and 1.599 in population II. The number of alleles and the expected heterozygosity (Hexp) values can provide important information for the discrimination of individuals and breeds. The index of expected heterozygosity in population I was 0.336 and 0.307 in population II. The information index (I) was 0,702 in population I and 0,576 in population II. For each population was found private alleles, in population I 6 alleles and in population II just 4 alleles. The results show high level of polymorphism of the studied populations of ducks. The obtained results can be used in the creation of new lines of ducks.У статті наведені результати досліджень генетичної структури двох популяцій качок породи шаосінь за використання дев’яти мікросателітних локусів. Птицю досліджували на качиних фермах компаній Zhejiang Generation Biological Science and Technology Co., Ltd. та Zhuji Guowei Poultry Development Co, Ltd. за підтримки лабораторії Poultry Genetics Laboratory of the Zhejiang Academy of Sciences (Zhejiang Province, PRC). Було встановлено, що середнє число ефективних алелів (Ne) на локус у популяції І складало 1,735, а для популяції ІІ – 1,599. Показники інформаційного індексу становили 0,702 (популяція І) та 0,576 (популяція ІІ). Фактична гетерозиготність у популяції І була 0,298, а у популяції ІІ – 0,269. У результаті нашого дослідження для кожної популяції були виявлені приватні алелі. З 9 досліджених локусів, у популяції І було виявлено 6 приватних алелів, в той час, коли популяція ІІ мала лише 4 локуси. Загалом у популяції І виявлено 23 приватних алелів, а у популяції ІІ – 5. Найбільша кількість приватних алелів була в локусі CMO11 (9), а найменша – 1 алель у локусі SMO7 та SMO10 в популяції І. Популяція ІІ була бідніша на приватні алелі, так у локусі APL79 було 2 та по 1 у CMO11, SMO7, SMO10. Отримані результати свідчать про високий рівень внутрішньопородного поліморфізму шаосінь, що дозволяє розробку стратегій збереження та використання генетичних ресурсів качки за використання аналізу поліморфних локусів мікросателіті

    A rapid and nondestructive method to determine the distribution map of protein, carbohydrate and sialic acid on Edible bird’s nest by hyper-spectral imaging and chemometrics

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    Edible bird’s nest (EBN) is a precious functional food in Southeast Asia. A rapid and nondestructive method for determining the distribution map of protein content (PC), carbohydrate content (CC) and sialic acid content (SAC) on EBN sample was proposed. Firstly, 60 EBNs were used for hyperspectral image acquisition, and components content (PC, CC and SAC) were determined by chemical analytical methods. Secondly, the spectral signals of EBN hyperspectral image and EBN components content were used to build calibration models. Thirdly, spectra of each pixel in EBN hyperspectral image were extracted, and these spectra were substituted in the calibration models to predict the PC, CC and SAC of each pixel in the EBN image, so the visual distribution maps of PC, CC and SAC on the whole EBN were obtained. It is the first time to show the distribution tendency of PC, CC and SAC on the whole EBN sample
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