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Item-level Forecasting for E-commerce Demand with High-dimensional Data Using a Two-stage Feature Selection Algorithm

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Journal of Systems Science and Systems Engineering 2022年第2期31卷 247-264页

作者： Hongyan Dai Qin Xiao nina Yan Xun Xu Tingting Tong Business School Central University of Finance and EconomicsBeijing 100081China Department of Management Operationsand MarketingCollege of Business AdministrationCalifornia State UniversityStanislausTurlockCA95382United States Institute of Supply Chain Analytics&International Business College Dongbei University of Finance and EconomicsDalian 116025China

With the rapid development of information technology and fast growth of Internet users,e-commerce nowadays is facing complex business environment and accumulating large-volume and highdimensional *** brings two challenges for demand ***,e-merchants need to find appropriate approaches to leverage the large amount of data and extract forecast features to capture various factors affecting the ***,they need to efficiently identify the most important features to improve the forecast accuracy and better understand the key drivers for demand *** solve these challenges,this study conducts a multi-dimensional feature engineering by constructing five feature categories including historical demand,price,page view,reviews,and competition for e-commerce demand forecasting on *** then propose a two-stage random forest-based feature selection algorithm to effectively identify the important features from the high-dimensional feature set and avoid *** test our proposed algorithm with a large-scale dataset from the largest e-commerce platform in *** numerical results from 21,111 items and 109 million sales observations show that our proposed random forest-based forecasting framework with a two-stage feature selection algorithm delivers 11.58%,5.81%and 3.68%forecast accuracy improvement,compared with the Autoregressive Integrated Moving Average(ARIMA),Random Forecast,and Random Forecast with one-stage feature selection approach,respectively,which are widely used in literature and *** study provides a useful tool for the practitioners to forecast demands and sheds lights on the B2C e-commerce operations management.

关键词： Forecasting e-commerce high-dimensional feature feature selection

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A Modified T-test Feature Selection Method and Its Application on the HapMap Genotype Data

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Genomics, Proteomics & Bioinformatics 2007年第3期5卷 242-249页

作者： nina Zhou Lipo Wang School of Electrical and Electronic Engineering Nanyang Technological University Singapore

Single nucleotide polymorphisms （SNPs） are genetic variations that determine the differences between any two unrelated individuals. Various population groups can be distinguished from each other using SNPs. For instance, the HapMap dataset has four population groups with about ten million SNPs. For more insights on human evolution, ethnic variation, and population assignment, we propose to find out which SNPs are significant in determining the population groups and then to classify different populations using these relevant SNPs as input features. In this study, we developed a modified t-test ranking measure and applied it to the HapMap genotype data. Firstly, we rank all SNPs in comparison with other feature importance measures including F-statistics and the informativeness for assignment. Secondly, we select different numbers of the most highly ranked SNPs as the input to a classifier, such as the support vector machine, so as to find the best feature subset corresponding to the best classification accuracy. Experimental results showed that the proposed method is very effective in finding SNPs that are significant in determining the population groups, with reduced computational burden and better classification accuracy.

关键词： SNP modified t-test F-statistics SVM

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关于新时代弘扬科学精神工作的几点思考

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今日科苑 2024年第4期 78-85页

作者：董亚峥张亦旒鲍妮娜中国科协科学技术传播中心北京100012

新时代在解决科技支撑发展、公民科学素质进一步提升等问题时,弘扬科学精神都是重要的内容。文章分析了关于科学精神的理论研究和社会实践面临的挑战,从科学精神的概念体系入手,分析了新时代弘扬科学精神的关注重点,并对具体工作提出建... 详细信息

新时代在解决科技支撑发展、公民科学素质进一步提升等问题时,弘扬科学精神都是重要的内容。文章分析了关于科学精神的理论研究和社会实践面临的挑战,从科学精神的概念体系入手,分析了新时代弘扬科学精神的关注重点,并对具体工作提出建议,包括弘扬科学家精神、一流学术传统构建、人类命运共同体构建、文化自信等内容。

关键词：科学精神科学家精神一流学术传统人类命运共同体文化自信

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Aeration performances and air—Water mass transfer on steep stepped weirs with horizontal and inclined steps

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Journal of Hydrodynamics 2022年第5期34卷 904-916页

作者： Yvan Arosquipa nina Rui Shi Davide Wüthrich Hubert Chanson The University of Queensland School of Civil EngineeringBrisbaneAustralia Department of Hydraulic Engineering Delft University of TechnologyDelftThe Netherlands

At hydraulic structures,some strong interactions may develop between fast flowing waters and the air adjacent to the water in motion that enhance the air-water transfer of atmospheric and volatile gases in the *** turn,in-stream structures may contribute to the aeration and re-oxygenation during *** present study aims to characterize the aeration performance of a steep stepped weir,based upon a detailed physical investigation of air-water interfacial properties across a relatively wide range of *** data showed a strong fragmentation of the air-water flows,a very broad range of entrained bubbles and drops,and a large amount of particle *** results implied a monotonic increase in re-aeration with increasing rate of energy dissipation,while the largest aeration efficiency was observed on the horizontal step weir chute,with the smallest on the 1V:2.33H inclined downward ***,the study showed that a steep stepped chute can make a sizeable contribution to the re-oxygenation of the waters,although the downward inclined steps reduce the re-aeration performances.

关键词： Stepped weirs aeration re-oxygenation physical modeling flow fragmentation

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Does intra-ruminal nitrogen recycling waste valuable resources? A review of major players and their manipulation

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Journal of Animal Science and Biotechnology 2018年第3期9卷 497-517页

作者： Thomas Hartinger nina Gresner Karl-Heinz Südekum Institute of Animal Science University of Bonn

Nitrogenous emissions from ruminant livestock production are of increasing public concern and, together with methane, contribute to environmental pollution. The main cause of nitrogen-(N)-containing emissions is the inadequate provision of N to ruminants, leading to an excess of ammonia in the rumen, which is subsequently excreted. Depending on the size and molecular structure, various bacterial, protozoal and fungal species are involved in the ruminal breakdown of nitrogenous compounds(NC). Decelerating ruminal NC degradation by controlling the abundance and activity of proteolytic and deaminating microorganisms, but without reducing cellulolytic processes, is a promising strategy to decrease N emissions along with increasing N utilization by ruminants. Different dietary options, including among others the treatment of feedstuffs with heat or the application of diverse feed additives, as well as vaccination against rumen microorganisms or their enzymes have been evaluated. Thereby, reduced productions of microbial metabolites, e.g. ammonia, and increased microbial N flows give evidence for an improved N retention. However, linkage between these findings and alterations in the rumen microbiota composition, particularly NC-degrading microbes, remains sparse and contradictory findings confound the exact evaluation of these manipulating strategies, thus emphasizing the need for comprehensive research. The demand for increased sustainability in ruminant livestock production requests to apply attention to microbial N utilization efficiency and this will require a better understanding of underlying metabolic processes as well as composition and interactions of ruminal NC-degrading microorganisms.

关键词： Ammonia Bacteria Deamination Hyper-ammonia producing Nitrogen efficiency Protein Proteolysis Protozoa Ruminant

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Bistable Stochastic Resonance Enhanced 4-ary PAM Signal Detection under Low SNR

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China Communications 2019年第4期16卷 196-207页

作者： Linlin Liang nina Zhang Haiyan Huang Zan Li School of Telecommunications Engineering Xidian University Xianyang Detachment of Chinese Armed Police Force School of Electronic and Information Engineering Lanzhou Jiaotong University The Collaborative Innovation Center of Information Sensing and Understanding at Xidian University

To boost the performance of 4-ary pulse amplitude modulated(PAM) at low signal-to-noise ratio(SNR), bistable stochastic resonance(BSR) system is introduced into digital communications system and get a reliable signal detection scheme. In this paper, we first analyse BSR system for different amplitudes of 4-ary PAM signals. The steadystate of the bistable system will be statistically distinct, and the feasibility of the proposed detection scheme is confirmed. On this basis, we present a detailed study on steady-state transitions of the BSR system, and an explicit expression of the bistable system parameters is derived. By setting the bistable system parameters, bistable system, 4-ary PAM signal, and noise reach the resonance state, and the BSR-based detection scheme is implemented. Moreover, we derive an analytical expression to calculate the symbol error rate(SER) of 4-ary PAM signals with the BSR-based detection under additive white Gaussian noise(AWGN). Finally, the simulation results validate that BSR-based detection scheme can improve the detection performance while efficiently reducing the symbol error rate.

关键词： 4-ary pulse amplitude modulated signal detection Low SNR Symbol error rate(SER) Bistable stochastic resonance(BSR)

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Influence of atmospheric circulation on precipitation in Altai Mountains

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Journal of Mountain Science 2017年第1期14卷 46-59页

作者： MALYGINA Natalia PAPINA Tatiana KONONOVA nina BARLYAEVA Tatiana Institute for Water and Environmental Problems Siberian Branch of the Russian Academy of SciencesBarnaul 656038Russia Institute of Geography Russian Academy of SciencesMoscow 117312Russia Laboratoire d'Astrophysique de Marseille UMR 7326 CNRS-INSUMarseille13388France

We analyzed the changes in precipitation regime in the Altai Mountains for 1959-2014 and estimate the influence of atmospheric circulations on these changes. Our study showed that during last 56 years the changes in the precipitation regime had a positive trend for the warm seasons(April-October),but weakly positive or negative trends for the cold seasons(November-March). It was found that these changes correspond to the decreasing contribution of "Northern meridional and Stationary anticyclone(Nm-Sa)" and "Northern meridional and East zonal(Nm-Ez)" circulation groups and to the increasing contribution of "West zonal and Southern meridional(Wz-Sm)" circulation groups,accordingly to the Dzerdzeevskii classification. In addition,it was found that the variation of precipitation has a step change point in 1980. For the warm seasons,the precipitation change at this point is associated with the reduced influence of "West zonal(Wz)","Northern meridional and Stationary anticyclone(Nm-Sa)" and "Northern meridional and Southern meridional(Nm-Sm)" circulation groups. For the cold seasons,a substantialincrease of "Wz-Sm" and a decrease of "Nm-Sa","Nm-Ez" circulation groups are responsible for the precipitation change in the two time periods(1959-1980 and 1981-2014).

关键词： Altai Mountains Precipitation Atmospheric circulation

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Multi-objective energy management system for DC microgrids based on maximum membership degree principle

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Journal of Modern Power Systems and Clean Energy 2018年第4期6卷 668-678页

作者： Panbao WANG Wei WANG nina MENG Dianguo XU School of Electrical Engineering and Automation Harbin Institute of Technology

With the increasing quantity of DC electrical equipment, DC microgrids have been paid more and more attention. This paper proposes an approach to multi-objective optimisation of an energy management system(EMS) for a DC microgrid that includes a hybrid energy storage system(HESS). The operating and maintenance cost and the loss of power supply probability(LPSP) of the system are used as optimisation targets. The power flows of all distributed generators(DGs) in the DC microgrid during operating period are optimized. Based on the improved differential evolution(DE) algorithm, and by using the multi-objective non-dominated sorting method and the maximum membership degree principle(MMDP) of fuzzy control, the overall satisfaction degree of Pareto solutions to power flow optimization can be obtained. Simulation results verify the effectiveness of the proposed EMS optimization scheme, which is able to achieve an effective trade-off between the economy and the reliability of microgrid operation.

关键词： DC microgrids Energy management system Multi-objective optimization Differential evolution algorithm Maximum membership degree

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Catheters coated with Zn-doped CuO nanoparticles delay the onset of catheter-associated urinary tract infections

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Nano Research 2017年第2期10卷 520-533页

作者： Yakov Shalom Ilana Perelshtein nina Perkas Aharon Gedanken Ehud Banin The Mina and Everard Goodman Faculty of Life Sciences and Institute for Advanced Materials and Nanotechnology Bar-Ilan University Ramat-Gan 52900 Israel The Department of Chemistry and Institute for Advanced Materials and Nanotechnology Bar-Ilan University Ramat-Gan 52900 Israel

Catheter-associated urinary tract infections （CAUTIs） are among the most common bacterial infections associated with medical devices. In the current study, the synthesis, coating, antibiofilm properties, and biocompatibility of urinary catheters coated with Zn-doped CuO （Zn0.12Cu0.880） nanoparticles （NPs） were examined. The doped NPs were synthesized and subsequently deposited on the catheter by the sonochemical method. The coated catheters displayed high antibiofilm activity and promising biocompatibility, as indicated by low in vitro cytotoxicity, negligible associated cytokine secretion, and absence of detectable irritation. The biocompatibility and ability of the Zn-doped CuO coating to inhibit biofilm formation were also evaluated in vivo using a rabbit model. Rabbits catheterized with uncoated catheters scored positive for CAUTI by day 4 of the experiment. In contrast, rabbits catheterized with Zn-doped CuO-coated catheters did not exhibit CAUTI until day 7 or remained completely uninfected for the whole duration of the 7-day experiment. Furthermore, the in vivo biocompatibility assays and examinations supported the biosafety of Zn-doped CuO-coated catheters. Taken together, these data highlight the potential of Zn-doped CuO nanocomposite as effective antibiofilm compound.

关键词： antibiofilm urinary tract infection catheter nanoparticle coating metal oxide

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汉钢1280 m^(3)高炉护炉操作实践

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山西冶金 2024年第5期47卷 134-136页

作者：张小帅杨妮娜吴诚诚陕钢集团汉钢公司炼铁厂陕西汉中724200

汉钢1280 m^(3)高炉炉役后期,炉缸侧壁温度偏高,根据实际运行情况,从原燃料条件、高炉操作与设计参数方面、高炉冷却制度等几方面,对高炉侵蚀机理进行分析,提出合理护炉操作。在确保炉况顺行的前提下,使用高钛矿护炉,提出有效护炉的合... 详细信息

汉钢1280 m^(3)高炉炉役后期,炉缸侧壁温度偏高,根据实际运行情况,从原燃料条件、高炉操作与设计参数方面、高炉冷却制度等几方面,对高炉侵蚀机理进行分析,提出合理护炉操作。在确保炉况顺行的前提下,使用高钛矿护炉,提出有效护炉的合理生铁含钛量含硅量。同时采用堵高温点上方风口,是降低侧壁温度的有效措施。采用这几方面措施后,成功的降低了炉缸侧壁温度,确保高炉正常生产直到安全的停炉大修,为高炉运行做到安全保障。

关键词：高温点高钛护炉侵蚀机理护炉操作

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