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Experimental Study on the Flow Around Two Tandem Cylinders with Unequal Diameters

Food and Nutrition Sciences（食品与营养科学） 2024年第4期 245页

作者： Elenga Michel Nkouka Rhode Gouollaly Tsiba Wossolo stephane Itoua Okouango Yvon Simplice Mananga Vital

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Journal of Ocean University of China 2014年第5期13卷 761-770页

作者： GAO Yangyang ETIENNE stephane WANG Xikun TAN Soon Keat Ocean College Zhejiang University State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of Oceanography SOA Mechanical Engineering Department Ecole Polytechnique de Montreal Maritime Research Centre and School of Civil and Environmental Engineering Nanyang Technological University

In this paper, flow around two circular cylinders in tandem arrangement with unequal diameters has been investigated using the particle image velocimetry technique(PIV) in a water channel. The upstream to downstream diameter ratio was kept constant at d/D = 2/3, the centre-to-centre distance was varied from 1.2D to 5D and the Reynolds number was varied from 1200 to 4800. The flow characteristics were analyzed through ensemble-averaged patterns of velocity, vorticity, normalized Reynolds stress contours and streamlines. Based on ensemble-averaged and instantaneous flow fields, different flow patterns, including single-wakeshedding at small spacing ratio, bi-stable flow behavior(alternating behavior of reattachment and vortex shedding) at intermediate spacing ratio and co-shedding pattern at large spacing ratio were observed. The effects of Reynolds number and the centre-to-centre spacing ratio on flow patterns and turbulent characteristics were also investigated. It was found that the diameter ratio appears to have a certain effect on the flow patterns at intermediate spacing ratios, where the reattachment of shear layer depends on the lateral width of the wake flow in the lee of the upstream cylinder. Extensive discussion on the distributions of Reynolds stress and turbulent kinetic energy was presented.

关键词： tandem cylinders with unequal diameters PIV flow patterns Reynolds stress distribution

Double Attention Mechanism for Sentence Embedding

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Double Attention Mechanism for Sentence Embedding

作者： KAKANAKOU MIGUEL stephane 太原理工大学

学位级别：硕士

句子嵌入是对具有相同意义的句子的学习表征,它是一种自然语言处理技术,单个句子在预定义的向量空间中被表示为实值向量。这种方法有助于通过生成相似句子的相似向量来执行句子的语义维度的模型化。,目的是训练一个模型,该模型可以自动... 详细信息

句子嵌入是对具有相同意义的句子的学习表征,它是一种自然语言处理技术,单个句子在预定义的向量空间中被表示为实值向量。这种方法有助于通过生成相似句子的相似向量来执行句子的语义维度的模型化。,目的是训练一个模型,该模型可以自动将句子转换为向量。现有的句子嵌入模型没有有效地使用注意力机制。本文提出一种新的句子嵌入模型,该模型有效地利用注意机制来提高模型的准确性。本文模型使用双重注意力机制,将递归神经网络(RNN)和卷积神经网络(CNN)组合进行使用。首先,使用双长短期记忆递归神经网络(RNN-LSTM),通过自关注机制来计算句子的本原表示,即第一表示;然后,通过卷积神经网络,使用基于汇集的注意机制计算汇集步骤期间使用的一组注意权重最后,将句子的原始表示与卷积神经网络的输出进行连接。双重注意机制的提出可以帮助模型保留更多句子的原始信息,从而产生更具代表性的特征向量。本文在三个不同的数据集上对句子进行分类任务,与现有方法进行对比。实验结果表明,与一些句子嵌入的方法相比,本文提出的模型性能有一定程度的提高。

关键词：句子嵌入双注意机制自然语言处理

Supply Chain Optimization: Case of African Companies and Traders in China

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Supply Chain Optimization: Case of African Companies and Tra...

作者： Ngando Yannick stephane 浙江工商大学

学位级别：硕士

Logistics *** and storage of products is the key to the supply chain and business *** the benefits of a longer supply chain outweigh the costs,developing more advanced logistics solutions in China will become a strategically urgent *** most cases,this means investing in people,processes and *** total cost of logistics from the point of departure to the destination is as important as the total *** chain visibility is a top priority for all companies,especially those operating in *** most products,many entities are involved in the transport and storage of goods from the point of departure to the destination,which hinders the transparency of the entire supply *** need to provide timely and accurate information at many points in their supply chain to respond quickly to market trends and distribution issues,but many companies have not received this *** to today,most companies expect greater visibility in the early stages of the *** achieve a high degree of transparency,companies need information-based intelligence,strict information requirements and close cooperation with everyone involved in the product supply *** the improvement of logistical capacity,large American companies have changed or are changing sales conditions to control goods at suppliers’ terminals,in order to gain visibility and reduce logistical *** serving the Chinese domestic market also hope to increase the visibility of the supply ***,technology allows computers and databases to communicate with each *** need to cooperate and share information with suppliers,service providers and transportation companies so that the end customer has full *** related to the transparency of the supply chain is the issue of the total cost of *** companies underestimate the total cost of transporting goods and products through the global supply chain,and it is often difficult t

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Air/CO2 cooling garment: Description and benefits of use for subjects exposed to a hot and humid climate during physical activities

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International Journal of Mining Science and Technology 2019年第6期29卷 899-903页

作者： Chady Al Sayed Ludwig Vinches Olivier Dupuy Wafa Douzi Benoit Dugue stephane Halle Department of Mechanical Engineering ecole de Technologie SuperieureMontreal H3C 1K3Canada Laboratory MOVE Faculty of Sports SciencesUniversity of PoitiersPoitiers 86073France

The severity of the hot and humid conditions to which miners are exposed increases as the depth of the work site *** can cause heat stress that can greatly affect the health and safety of *** resolve this,a cooling garment has been developed that uses an atmospheric discharge of liquid CO2 to create a cool microclimate with an average temperature of 12.5(±0.4)℃ beneath the *** evaluate the garment's cooling efficiency,19 male subjects participated in an experimental *** two modes,cooling on and off,were *** physiological differences were found between the two modes after minute 27(p<0.05)until the end of the recovery phase for the heart rate(maximum difference of 10 beats per minute)and the internal body temperature(maximum difference of 0.33℃).It was found that the modes also affected the subjects'*** ON-mode was associated with better well-being and thermal comfort,and reduced humidity *** of exertion were lower in the ON-mode condition from minute *** findings provide strong evidence of the ability of this cooling garment to reduce heat stress in hot and humid conditions similar to those encountered in deep mines.

关键词： Cooling garment Deep mining Hot and humid Liquid CO2 expansion Physiological measurements Perceptual responses

Credit, funding, margin, and capital valuation adjustments for bilateral portfolios

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Probability, Uncertainty and Quantitative Risk 2017年第1期2卷 145-170页

作者： Claudio Albanese Simone Caenazzo stephane´Crepey IMEX LondonUK CASS School of Business LondonUK LaMME Univ EvryCNRSUniversite Paris-Saclay91037EvryFrance

We apply to the concrete setup of a bank engaged into bilateral trade portfolios the XVA theoretical framework of Albanese and Crepey(2017),whereby´so-called contra-liabilities and cost of capital are charged by the bank to its clients,on top of the fair valuation of counterparty risk,in order to account for the incompleteness of this *** transfer of the residual reserve credit capital from shareholders to creditors at bank default results in a unilateral CVA,consistent with the regulatory requirement that capital should not diminish as an effect of the sole deterioration of the bank credit *** funding cost for variation margin(FVA)is defined asymmetrically since there is no benefit in holding excess capital in the *** is fungible as a source of funding for variation margin,causing a material FVA *** introduce a specialist initial margin lending scheme that drastically reduces the funding cost for initial margin(MVA).Our capital valuation adjustment(KVA)is defined as a risk premium,*** cost of remunerating shareholder capital at risk at some hurdle rate.

关键词： Counterparty risk Credit valuation adjustment(CVA) Cost of funding variation margin(FVA) Cost of funding initial margin(MVA) Cost of capital(KVA)

Agroecological management of a soil-dwelling orthopteran pest in vineyards

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Insect Science 2018年第3期25卷 475-486页

作者： Jerry Asalma Nboyine stephane Boyer David J. Saville Stephen David Wratten Bio-Protection Research Centre Lincoln University Christchurch New Zealand CSIR Savanna Agriculture Research Institute Tamale Ghana Environmental and Animal Sciences Unitec Institute of Technology Auckland New Zealand Saville Statistical Consulting Limited Lincoln New Zealand

The efficacy of different combinations of undervine and inter-row treatments for managing a soil-dwelling orthopteran pest, weta （Hemiandrus sp.）, in vineyards was investigated over 2 seasons. This insect damages vine buds, thus reducing subsequent grape yield. The undervine treatments comprised pea straw mulch, mussel shells, tick beans [Viciafaba Linn. var minor （Fab）], plastic sleeves on vine trunks （treated control） and control （no intervention）, while inter-rows contained either the existing vegetation or tick beans. Treatments were arranged in a randomized complete block design with 10 replicates. Data were collected on weta densities, damage to beans and components of yield. The latter were numbers of bud laid down per vine, shoots per bud, clusters per shoot, grape bunches per vine, bunch weight and yield. The undervine treatments significantly affected all variables except the number of shoots per bud. In contrast, none of the variables was significantly affected by the inter-row treatments or their interaction with undervine treatments, apart from weta density. At the end of the experiment, weta density in the shell treatment was about 58% lower than in the control. As a result, there was about 39% significant yield increase in that treatment compared to the control. Although the undervine beans and sleeves treatments increased yield, there were no reductions in weta density. With undervine beans, the insect fed on the bean plants instead of vine buds. Thus, yield in that treatment was approximately 28% higher than in the control. These results demonstrate that simple agroecological management approaches can reduce above-ground damage by soil-dwelling insects.

关键词： cover crops grapevine yield pest management soil-dwelling insects vineyards yield loss

Bumblebees adjust protein and lipid collection rules to the presence of brood

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Current Zoology 2019年第4期65卷 437-446页

作者： stephane Kraus Tamara Gomez-Moracho Cristian Pasquaretta Gerard Latil Audrey Dussutour Mathieu Lihoreau Research Center on Animal Cognition (CRCA) Center for Intergrative Biology (CBI)CNRS University Paul Sabatier Toulouse France

Animals have evolved foraging strategies to acquire blends of nutrients that maximize fitness traits. In social insects, nu trie nt regulation is complicated by the fact that few in dividuals, the foragers, must address the diverge nt nutritional n eeds of all colony members simulta neously, includi ng other workers, the reproductives, and the brood. Here we used 3D nutritional geometry design to examine how bumblebee workers regulate their collection of 3 major macronutrients in the presence and absenee of brood. We provided small colonies artificial nectars (liquid diets) and pollens (solid diets) varying in their compositions of proteins, lipids, and carbohydrates during 2 weeks. Colo nies give n a choice betwee n nutrition ally complementary diets self-selected foods to reach a target ratio of 71% proteins, 6% carbohydrates, and 23% lipids, irrespective of the presenee of brood. Whe n con fined to a single nutrition ally imbalanced solid diet, colonies without brood regulated lipid collection and over-collected protein relative to this target ratio, whereas colonies with brood regulated both lipid and protein collection. This brood effect on the regulation of nutrient collection by workers suggests that protein levels are critical for larval development. Our results highlight the importa nee of con sidering bee nu trition as a multidimensi onal phe no men on to better assess the effects of environmental impoverishment and malnutrition on population declines.

关键词： artificial diets Bombus terrestris bumble bees nutritional geometry rule of compromise

Aerosol Optical Properties and Its Radiative Forcing over Yulin, China in 2001 and 2002

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Advances in Atmospheric Sciences 2009年第3期26卷 564-576页

作者：车慧正张小曳 stephane ALFRARO Bernadette CHATENET Laurent GOMES 赵剑琦 Key Laboratory of Atmospheric Chemistry Centre for Atmosphere Watch and ServicesChinese Academy of Meteorological Sciences China Meteorological AdministrationBeijing 100081 Laboratoire Inter-Universitaire des Systmes Atmosphriques Universit Paris Ⅶ/Paris Ⅻ94010 Crteil Cedex France Centre National de la Recherche Scientifique Meto-France/CNRM/GMEI/MNPCA31057ToulouseFrance State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029

The aerosol optical properties and direct radiative forcing over the Mu Us desert of northern China, acquired through a CE318 sunphotometer of the ground-based Aerosol Robotic Network （AERONET）, are analyzed. The seasonal variations in the aerosol optical properties are examined. The effect of meteorological elements （pressure, temperature, water vapor pressure, relative humidity and wind speed） on the aerosol optical properties is also studied. Then, the sources and optical properties under two different cases, a dust event and a pollution event, are compared. The results show that the high aerosol optical depth （AOD） found in Yulin was mostly attributed to the occurrence of dust events in spring from the Mu Us desert and deserts of West China and Mongolia, as well as the impacts of anthropogenic pollutant particles from the middle part of China in the other seasons. The seasonal variation and the probability distribution of the radiative forcing and the radiative forcing efficiency at the surface and the top of the atmosphere are analyzed and regressed using the linear and Gaussian regression methods.

关键词： aerosol optical properties aerosol radiative forcing Mu Us desert China

Relaxation Schemes for the M1 Model with Space-Dependent Flux:Application to Radiotherapy Dose Calculation

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Communications in Computational Physics 2016年第1期19卷 168-191页

作者： Teddy Pichard Denise Aregba-Driollet stephane Brull Bruno Dubroca Martin Frank Centre Lasers Intenses et Applications Universite de Bordeaux351 cours de la liberationTalence33400France Mathematics division Center for Computational Engineering ScienceRheinisch-Westf¨alische Technische HochschuleSchinkelstrasse 2Aachen52062Germany Institut de Mathematiques de Bordeaux Universite de Bordeaux351 cours de la liberationTalence33400France

Because of stability constraints,most numerical schemes applied to hyperbolic systems of equations turn out to be costly when the flux term is multiplied by some very large *** problem emerges with the M_(1)system of equations in the field of radiotherapy when considering heterogeneous media with very disparate ***,the flux term of the M_(1)system is non-linear,and in order for the model to be well-posed the numerical solution needs to fulfill conditions called *** this paper,we propose a numerical method that overcomes the stability constraint and preserves the realizability *** this purpose,we relax the M_(1)system to obtain a linear flux *** we extend the stencil of the difference quotient to obtain *** scheme is applied to a radiotherapy dose calculation example.

关键词： Radiotherapy Moments models relaxation models method of characteristics