检索结果-南通市图书馆

Multivariate adaptive regression splines and neural network models for prediction of pile drivability

Geoscience Frontiers 2016年第1期7卷 45-52页

作者： Wengang Zhang Anthony t.c.Goh School of civil and Environmental Engineering Nanyang Technological UniversitySingapore 639798Singapore

Piles are long, slender structural elements used to transfer the loads from the superstructure through weak strata onto stiffer soils or rocks. For driven piles, the impact of the piling hammer induces compression and tension stresses in the piles. Hence, an important design consideration is to check that the strength of the pile is sufficient to resist the stresses caused by the impact of the pile hammer. Due to its complexity, pile drivability lacks a precise analytical solution with regard to the phenomena *** situations where measured data or numerical hypothetical results are available, neural networks stand out in mapping the nonlinear interactions and relationships between the system’s predictors and dependent responses. In addition, unlike most computational tools, no mathematical relationship assumption between the dependent and independent variables has to be made. Nevertheless, neural networks have been criticized for their long trial-and-error training process since the optimal configuration is not known a priori. this paper investigates the use of a fairly simple nonparametric regression algorithm known as multivariate adaptive regression splines（MARS）, as an alternative to neural networks, to approximate the relationship between the inputs and dependent response, and to mathematically interpret the relationship between the various parameters. In this paper, the Back propagation neural network（BPNN） and MARS models are developed for assessing pile drivability in relation to the prediction of the Maximum compressive stresses（McS）, Maximum tensile stresses（MtS）, and Blow per foot（BPF）. A database of more than four thousand piles is utilized for model development and comparative performance between BPNN and MARS predictions.

关键词： Back propagation neural network Multivariate adaptive regression splines Pile drivability computational efficiency Nonlinearity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Developments in Processing of Functionally Gradient Metals and Metal–ceramic composites:A Review

引用

Acta Metallurgica Sinica(English Letters) 2014年第5期27卷 825-838页

作者： t.P.D.Rajan B.c.Pai Materials Science and technology Division CSIR-National Institute for Interdisciplinary Science and TechnologyIndustrial Estate PO

Functionally gradient/graded materials （FGMs）, an emerging new class of materials, are the outcome of the recent innovative concepts in materials technology. FGMs are in their early stages of evolution and expected to have a strong impact on the design and development of new components and structures with better performance. FGMs exhibit gradual transitions in the microstructure and/or the composition in a specific direction, the presence of which leads to variation in the functional performance within a part. the presence of gradual transitions in material composition in FGMs can reduce or eliminate the deleterious stress concentrations and result in a wide gradation of physical and/or chemical properties within the material. Functionally graded metal-ceramic composites are also getting the attention of the researchers. Among the fabrication routes for FGMs such as chemical vapour deposition, physical vapour deposition, the sol-gel technique, plasma spraying, molten metal infiltration, self propagating high temperature synthesis, spray forming, centrifugal casting, etc., the ones based on solidification route are preferred for FGMs because of their economics and capability to make large size products. the present paper discusses and compares various solidification processing tech- niques available for the fabrication of functionally gradient metals and metal-ceramic composites and lists their properties and possible applications. the other processing methods are briefly described.

关键词： Functionally gradient materials Solidification Aluminium centrifugal casting Infiltration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Water solubility enhancements of pyrene by single and mixed surfactant solutions

引用

Journal of Environmental Sciences 2001年第4期13卷 491-496页

作者： Zhu, L.-z. chiou, c.t. Department of Environmental Science Zhejiang University Hangzhou 310028 China

Water solubility enhancements of pyrene by both single-surfactant and mixed-surfactant solutions were compared and evaluated. the solubility of pyrene in water was greatly enhanced by each of triton X-100 (tX100), triton X-405 (tX405), Brij 35 and SDS, in which the water solubility enhancements increased with increasing surfactant concentrations. the extent of solubility enhancements at surfactant concentrations below. the cMc is the order of tX100 > Brij 35 > tX405 > SDS; the sequence at surfactant concentrations above the cMc is tX100 > Brij 35 > SDS > tX405. Pyrene was solubilized synergistically by anionic-nonionic mixed surfactant solutions, especially at low surfactant concentrations. the synergistic power of the mixed surfactants is SDS-tX405 > SDS-Brij 35 > SDS-tX100. the synergism as noted is attributed to increasing Kmc and/or decreasing the cMc of the mixed surfactant solution. For SDS-tX405 and SDS-Brij 35 mixed surfactant solutions, an increase in Kmc is coupled with a decrease in the cMc; for SDS-tX100, only a decreased in the cMc value is noted. Mixed-surfactant solutions may improve the performance of the surfactant-enhanced remediation (SER) of soils by increasing the bioavailability and biodegradation of non-aqueous-phase organic pollutants and reducing the level of surfactant pollution and remediation expenses.

关键词： Biodegradation concentration (process) Solubility Water

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

the use of the node-based smoothed finite element method to estimate static and seismic bearing capacities of shallow strip footings

引用

Journal of Rock Mechanics and Geotechnical Engineering 2022年第1期14卷 180-196页

作者： H.c.Nguyen t.Vo-Minh Department of civil and environmental engineering imperial college londonuk Department of civil engineering and industrial design university of liverpoolliverpooluk Faculty of civil engineering ho chi minh city university of technology(hutech)ho chi minh cityviet nam

the node-based smoothed finite element method(NS-FEM)is shortly presented for calculations of the static and seismic bearing capacities of shallow strip footings.A series of computations has been performed to assess variations in seismic bearing capacity factors with both horizontal and vertical seismic *** results obtained agree very well with those using the slip-line method,revealing that the magnitude of the seismic bearing capacity is highly dependent upon the combinations of various directions of both components of the seismic *** upward vertical seismic acceleration reduces the seismic bearing capacity compared to the downward vertical seismic acceleration in *** addition,particular emphasis is placed on a separate estimation of the effects of soil and superstructure inertia on each seismic bearing capacity *** the effect of inertia forces arising in the soil on the seismic bearing capacity is non-trivial,and the superstructure inertia is the major contributor to reductions in the seismic bearing *** tables and charts are given for practical application to the seismic design of the foundations.

关键词： Limit analysis Node-based smoothed finite element method(NS-FEM) Second-order cone programming(SOcP) Seismic bearing capacity Strip footing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A tool for estimating antiretroviral medication coverage for HIV-infected women during pregnancy(PMtct-Act)

引用

Global Health Research and Policy 2019年第1期4卷 87-94页

作者： Bruce A.larson Nafisa Halim Isaac tsikhutsu Margaret Bii Peter coakley Peter c.Rockers Department of Global Health Boston University School of Public Health801 Massachusetts AvenueBostonMA 02118USA Kenya Medical Research Institute U.S.Army Medical Research DirectorateAfricaKenya U.S.Military HIV Research Program Walter Reed Army Institute of ResearchSilver SpringMDUSA Henry Jackson Foundation MRI KerichoKenya

Background:In the typical prevention of mother to child transmission(PMtct)of HIV cascade of care discussion or analysis,the period of analysis begins at the first visit for antenatal care(ANc)for that *** starting point is problematic for two reasons:(1)a large number of HIV-infected women are already on life-long antiretroviral therapy(ARt)when presenting for ANc;and(2)women present to ANc at different gestational *** PMtct ARt coverage tool(PMtct-Act),which estimates the proportion of days covered(PDc)with ARt,was developed to address each of these ***:PDc is a preferred method to measure adherence to chronic medications,such as *** evaluating the PMtct cascade of care,as indicated by PDc with ARt over various time periods,a“starting point”based on a specific day before delivery must be defined that applies to all women(treatment experienced or naïve at the first ANc visit at any gestational age).Using the example of 168 days prior to delivery(24 weeks),PMtct-Act measures PDc with ARt during that ***-Act is provided as a StAtA *** an example dataset for two women(ID1 is treatment experienced;ID2 is treatment naïve),the details of each major portion of the tool(Parts 1-5)are ***-Act along with the intermediate datasets created during the analysis are provided as supplemental ***:Evaluating the PMtct cascade of care requires a standard definition of the follow-up period during pregnancy that applies to all HIV-infected pregnant women and a standard measure of ***-Act is a new tool that fits this ***-Act can also be easily adjusted to evaluate other ante-and post-natal periods(e.g.,final 4 weeks,final 8 weeks,complete pregnancy period,initial 24 weeks postpartum,time periods consistent with infant HIV testing guidelines).

关键词： HIV Pregnancy Prevention of mother-to-child transmission cascade of care Pill count coverage Proportion of days covered

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Quantum communication via controlled holes in the statistical distribution of excitations in a nanoresonator coupled to a cooper pair box

引用

chinese Physics B 2012年第3期21卷 74-79页

作者： c.Valverde A.t.Avelar B.Baseia Universidade Paulista Rod.BR 153km 774845-090 Goia niaGOBrazil Universidade Estadual de Goiás Rod.BR 153310575132-903 AnápolisGOBrazil Instituto de Física Universidade Federal de Goiás74001-970 Goia niaGOBrazil

We propose a scheme to transmit information via the statistical distribution of excitations of a nanomechanical resonator. It employs a controllable coupling between this system and a cooper pair box. the success probability and the fidelity are calculated and compared with those obtained in an atom-field system in different regimes. Addtionaly, the scheme can also be applied to prepare low excited Fock states.

关键词： quantum communication quantum state engineering superconducting circuits nanome- chanical resonator

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Performance analysis of InSb based QWFEt for ultra high speed applications

引用

Journal of Semiconductors 2015年第1期36卷 60-63页

作者： t.D.Subash t.Gnanasekaran c.Divya K.N.S.K college of Engineering Nagercoil-629901 India Department of It RMK College of Engineering and Technology 629401 India centre for It & Eng Manonmaniam Sundaranar University 627012 India

An indium antimonide based QWFEt（quantum well field effect transistor） with the gate length down to 50 nm has been designed and investigated for the first time for L-band radar applications at 230 GHz. QWFEts are designed at the high performance node of the International technology Road Map for Semiconductors（ItRS）requirements of drive current（Semiconductor Industry Association 2010）. the performance of the device is investigated using the SYNOPSYS cAD（tcAD） software. In Sb based QWFEt could be a promising device technology for very low power and ultra-high speed performance with 5–10 times low Dc power dissipation.

关键词： QWFEt InSb gate length cut-off frequency short-channel effects

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamically encircling an exceptional point in antiparity-time symmetric systems:asymmetric mode switching for symmetry-broken modes

引用

Light(Science & Applications) 2019年第1期8卷 376-384页

作者： Xu-Lin Zhang tianshu Jiang c.t.chan State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchunChina Department of Physics The Hong Kong University of Science and TechnologyClear Water BayHong KongChina

Dynamically encircling an exceptional point(EP)in parity-time(Pt)symmetric waveguide systems exhibits interesting chiral dynamics that can be applied to asymmetric mode switching for symmetric and anti-symmetric *** counterpart symmetry-broken modes(i.e.,each eigenmode is localized in one waveguide only),which are more useful for applications such as on-chip optical signal processing,exhibit only non-chiral dynamics and therefore cannot be used for asymmetric mode ***,we solve this problem by resorting to anti-parity-time(anti-Pt)symmetric systems and utilizing their unique topological structure,which is very different from that of Pt-symmetric *** find that the dynamical encircling of an EP in anti-Pt-symmetric systems with the starting point in the Pt-broken phase results in chiral *** a result,symmetry-broken modes can be used for asymmetric mode switching,which is a phenomenon and application unique to anti-Pt-symmetric *** perform experiments to demonstrate the new wave-manipulation scheme,which may pave the way towards designing on-chip optical systems with novel functionalities.

关键词： symmetric asymmetric symmetry

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Adverse outcomes in type 1 diabetic pregnant women with proliferative diabetic retinopathy

引用

International Journal of Ophthalmology(English edition) 2011年第4期4卷 443-446页

作者： c c t Helen I tajunisah S c Reddy Department of Ophthalmology Faculty of Medicine University of Malaya Department of Ophthalmology Faculty of Medicine International Medical University Clinical School

AIM: to report maternal and fetal adverse outcomes, in spite of appropriate treatment and regular follow up, in diabetic pregnant women with proliferative diabetic retinopathy. MEtHODS: case series of four young pregnant diabetics aged between 20 and 25 years with type 1 diabetes mellitus and proliferative diabetic retrinopathy. RESULtS: the maternal adverse outcomes were abortion in one patient, pre-eclampsia and preterm delivery in one patient, and renal failure requiring dialysis in one patient. the fetal adverse outcomes were neonatal death in one case and premature baby in another case. cONcLUSION: these cases highlight the fact that diabetic pregnant women should be closely followed up by the obstetricians and physicians when they have proliferative retinopathy. the proliferative diabetic retinopathy should be considered as a part of the assessment when counseling a diabetic woman in antenatal check up and also in the follow up visits during pregnancy.

关键词： pregnancy type I diabetes mellitus proliferative diabetic retinopathy vitreous haemorrhage

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

On the simulation of shared autonomous micro-mobility

引用

communications in transportation Research 2022年第1期2卷 104-115页

作者： Naroa coretti Sanchez Inigo Martinez Luis Alonso Pastor Kent larson MIt Media Lab CambridgeMAUSA University of Navarra San SebastianSpain

Fast urbanization and climate change require innovative systems for an efficient movement of people and goods in *** trends towards vehicle-sharing,autonomous vehicles,and the use of micro-mobility systems gain strength,the intersection of these fields appears as an area of great *** could potentially bring the convenience of on-demand mobility into already prevalent shared micro-mobility systems(SMMS),increasing their efficiency and incentivizing more people to use active mobility *** novelty of introducing autonomous driving technology into SMMS and their inherent complexity requires tools to assess and quantify the potential impact of autonomy on fleet performance and user *** paper presents an ad-hoc agentbased simulator for the assessment of the fleet behavior of autonomous SMMS in realistic scenarios,including a rebalancing system based on demand *** also allows comparing its performance to station-based and dockless *** proposed simulation framework is highly configurable and flexible and works with high resolution and precision geospatial *** results of studies carried out with this simulation tool could provide valuable insights for many stakeholders,including vehicle design engineers,fleet operators,city planners,and governments.

关键词： Future mobility Autonomous vehicles Micro-mobility Agent-basedsimulation Multi-agentsystems

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：