检索结果-南通市图书馆

Parallel Implicit-Explicit General Linear Methods

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications on Applied Mathematics and Computation 2021年第4期3卷 649-669页

作者： Steven roberts Arash Sarshar Adrian Sandu Computational Science Laboratory Virginia Polytechnic Institute and State UniversityBlacksburgVA 24060USA

High-order discretizations of partial differential equations(PDEs)necessitate high-order time integration schemes capable of handling both stiff and nonstiff operators in an efficient ***-explicit(IMEX)integration based on general linear methods(GLMs)offers an attractive solution due to their high stage and method order,as well as excellent stability *** IMEX characteristic allows stiff terms to be treated implicitly and nonstiff terms to be efficiently integrated *** work develops two systematic approaches for the development of IMEX GLMs of arbitrary order with stages that can be solved in *** first approach is based on diagonally implicit multi-stage integration methods(DIMSIMs)of types 3 and *** second is a parallel generalization of IMEX Euler and has the interesting feature that the linear stability is independent of the order of *** experiments confirm the theoretical rates of convergence and reveal that the new schemes are more efficient than serial IMEX GLMs and IMEX Runge-Kutta methods.

关键词： Parallel Time integration IMEX methods General linear

Macronutrients and Health—Steps to Ameliorating the Nutrition Transition Trap

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2001年第1期14卷 124-129页

作者： D. C. K. roberts School of Health Sciences Faculty of Medicine and Health Sciences

Countries that have made the health transition from a communicable disease base to a non communicable disease base find themselves gripped in an epidemic of wealth created diseases mediated by altered macronutrient intakes, energy intakes and reduction in physical activity. Avoiding the negative impact of the nutrition transition while accepting the positive aspects of the wealth transition can best be achieved by focussing on publicising the benefits of a low fat diet in the context of an active lifestyle. How this is achieved should reflect ecologically sound food production appropriate to national needs. Countries that achieve this will be in the best position to capitalize on the reduction in communicable disease rates without causing a rise in non communicable disease rates.

关键词： Nutrition Policy Nutritional Status Public Health Dietary Fats Energy Intake Humans Life Style Physical Fitness

Study of the wall adhesive tensile contact of moist iron ore bulk solids

在线全文

学校读者我要写书评

暂无评论

Particuology 2020年第3期18卷 67-75页

作者： Tao Fang Wei Chen Jens Plinke Craig Wheeler Alan roberts School of Civil Engineering East China Jiaotong UniversityNanchang 330013China School of Engineering The University of NewcastleCallaghan 2308Australia

The adhesive tensile stress between moist bulk iron ore solids and wall surfaces are critical to control and avoid blockage in large throughput material handling *** this study,an experimental system was designed to investigate the adhesive tensile contact between a range of iron ore materials and wall lining *** contact mechanism between the material specimen and the wall surface was initially *** experimental results indicated that the adhesive tensile stress is dependent on both the moisture content and the applied major consolidation stress,with the former exhibiting more significant contribution to increasing the magnitude of *** surface roughness of the wall showed a negligible effect in determining the adhesive tensile ***,the iron ore sample with a higher fines content was observed to be able to achieve a higher adhesive tensile stress compared to the coarse ***,the insights resulting from the study demonstrated practical applicability through measures such as blending and/or beneficiation,which reduce the adhesive tensile stress and minimise blockages.

关键词： Wet sticky material Adhesive tensile stress Wall linings Liquid bridge force Capillary stress Soil texture

Quality measures of reconstruction filters for stereoscopic volume rendering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computational Visual Media 2016年第1期2卷 19-30页

作者： David A.T.roberts Ioannis Ivrissimtzis School of Engineering and Computing Sciences Durham University

In direct volume rendering(DVR), the choice of reconstruction filter can have a significant effect on the visual appearance of the images produced and thus, on the perceived quality of a DVR rendered scene. This paper presents the results of a subjective experiment where participants stereoscopically viewed DVR rendered scenes and rated their subjective *** statistical analysis of the results focuses on the relationship between the quality of the stereoscopic scene and properties of the filters such as post-aliasing and smoothing, as well as the relationship between the quality of the stereoscopic scene and properties of the rendered images such as shape *** experiment evaluated five reconstruction filters on four different volumetric datasets. Participants rated the stereoscopic scenes on four quality measures:depth quality, depth layout, lack of jaggyness, and sharpness. The results show that the correlation between the quality measures and post-aliasing and smoothing, which are properties associated with each reconstruction filter, is moderate and statistically insignificant. On the other hand, the correlation between the quality measures and compactness, which is a property specific to each rendered image, is strong and statistically significant.

关键词： direct volume rendering(DVR) reconstruction filters stereoscopic user evaluations

Plant Growth Promoting Fungal and Bacterial Endophytes of Tall Fescue: A Review

在线全文

学校读者我要写书评

暂无评论

Grass Research 2022年第1期2卷 14-19页

作者： Elizabeth Lewis roberts Southern Connecticut State University New Haven Connecticut06515USA

Plant growth promoting bacteria(PGPB)directly and indirectly influence the fitness of their host *** much of the work on plant growth promoting bacteria is from various plant rhizospheres,less is known about the strains that inhabit the internal spaces of plant ***,Clavicipitalean fungal endophytes of cool season grasses have been intensely investigated for the past few *** plant growth promoting bacteria,the fungal endophytes also promote the health of their *** paper highlights the current knowledge of plant growth promoting bacterial and fungal endophytes of tall fescue(Lolium arundinaceum=Schedonorus arundinaceaus=Festuca arundinacea)which protect the plant from both abiotic and biotic *** of the work presented indicates just how little is known about the inter-relationships between the multiple endophytic microbial colonizers of turf grasses.

关键词： donor intense spaces

A vector autoregression weather model for electricity supply and demand modeling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2018年第4期6卷 763-776页

作者： Yixian LIU Matthew C.roberts Ramteen SIOSHANSI Department of Integrated Systems Engineering The Ohio State University Department of Agricultural Environmental and Development Economics The Ohio State University

Weather forecasting is crucial to both the demand and supply sides of electricity systems. Temperature has a great effect on the demand side. Moreover, solar and wind are very promising renewable energy sources and are, thus, important on the supply side. In this paper, a large vector autoregression(VAR) model is built to forecast three important weather variables for 61 cities around the United States. The three variables at all locations are modeled as response variables. Lag terms are used to capture the relationship between observations in adjacent periods and daily and annual seasonality are modeled to consider the correlation between the same periods in adjacent days and years. We estimate the VAR model with16 years of hourly historical data and use two additional years of data for out-of-sample validation. Forecasts of up to six-hours-ahead are generated with good forecasting performance based on mean absolute error, root mean square error, relative root mean square error, and skill scores. Our VAR model gives forecasts with skill scoresthat are more than double the skill scores of other forecasting models in the literature. Our model also provides forecasts that outperform persistence forecasts by between6% and 80% in terms of mean absolute error. Our results show that the proposed time series approach is appropriate for very short-term forecasting of hourly solar radiation,temperature, and wind speed.

关键词： Forecasting Solar irradiance Wind speed Temperature Vector autoregression Skill scores

Zircon U-Pb-Hf constraints from Gongga Shan granites on young crustal melting in eastern Tibet

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2019年第3期10卷 885-894页

作者： Nick M.W.roberts Michael P.Searle NERC Isotope Geosciences Laboratory British Geological Survey Environment Science Centre Department of Earth Sciences University of Oxford

The Gongga Shan batholith is a complex granitoid batholith on the eastern margin of the Tibetan Plateau with a long history of magmatism spanning from the Triassic to the Pliocene. Late Miocene-Pliocene units are the youngest exposed crustal melts within the entire Asian plate of the Tibetan ***, we present in-situ zircon Hf isotope constraints on their magmatic source, to aid the understanding of how these young melts were formed and how they were exhumed to the surface. Hf isotope signatures of Eocene to Pliocene zircon rims(ε_(Hf)(t)=-4 to +4), interpreted to have grown during localised crustal melting, are indicative of melting of a Neoproterozoic source region, equivalent to the nearby exposed Kangding Complex. Therefore, we suggest that Neoproterozoic crust underlies this region of the Songpan-Ganze terrane, and sourced the intrusive granites that form the Gongga Shan batholith. Localised young melting of Neoproterozoic lower or middle crust requires localised melt-fertile lithologies. We suggest that such melts may be equivalent to seismic and magnetotelluric low-velocity and high-conductivity zones or "bright spots" imaged across much of the Tibetan Plateau. The lack of widespread exposed melts this age is due either to the lack of melt-fertile rocks in the middle crust, the very low erosion level of the Tibetan plateau, or to a lack of mechanism for exhuming such melts. For Gongga Shan, where some melting is younger than nearby thermochronological ages of low temperature cooling, the exact process and timing of exhumation remains enigmatic, but their location away from the Xianshuihe fault precludes the fault acting as a conduit for the young melts. We suggest that underthrusting of dry granulites of the lower Indian crust(Archaean shield) this far northeast is a plausible mechanism to explain the uplift and exhumation of the eastern Tibetan Plateau.

关键词： Tibet Himalaya Hf isotopes Zircon Crustal melting

Identifying female phenotypes that promote behavioral isolation in a sexually dimorphic species of fish Etheostoma zonale

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2021年第2期67卷 225-236页

作者： Natalie S.roberts Tamra C.MENDELSON Department of Biological Sciences University of Maryland Baltimore CountyBaltimoreMD21250USA

In sexually dimorphic species characterized by exaggerated male ornamentation,behavioral isola-tion is often attributed to female preferences for conspecific male ***,in a number of sexu-ally dimorphic species,male mate choice also results in behavioral *** many of these cases,the female traits that mediate species boundaries are *** in sexually dimorphic species typically lack many of the elaborate traits that are present in males and that are often used for taxonomic classification of *** a diverse and largely sexually dimorphic group of fishes called darters(Percidae:Etheostoma),male mate choice contributes to behavioral isolation be-tween a number of species;however,studies addressing which female traits males prefer are *** this study,we identified the dominant female pattern for two sympatric species,Etheostoma zonale and Etheostoma barrenense,using pattern energy analysis,and we used discriminate func-tion analysis to identify which aspects of female patterning can reliably classify *** then tested the role of female features in male mate choice for ***,by measuring male preference for computer animations displaying the identified(species specific)conspecific *** found that the region above the lateral line is important in mediating male mate preferences,with males spending a significantly greater proportion of time with animations exhibiting conspecific female patterning in this region than with animations exhibiting heterospecific female *** results suggest that the aspects of female phenotypes that are the target of male mate choice are different from the conspicuous male phenotypes that traditionally characterize species.

关键词： darters discriminant function analysis Etheostoma female phenotype male mate choice 3D animations

Cuckoo search approach for automatic train regulation under capacity limitation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2023年第4期66卷 299-300页

作者： Zhuopu HOU Min ZHOU Clive roberts Hairong DONG State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University School of Electronic Electrical and Systems Engineering University of Birmingham

Dear editor, In the daily operation of metro systems, external interferences(e.g., signal system malfunction, bad weather) that can affect normal train operation are inevitable. Hence,effective train regulation measures are necessary to ensure service quality and efficient operation [1, 2]. With the explosive growth in the urban rail transit ridership in recent years,

关键词：