检索结果-南通市图书馆

Using big data and machine learning to rank traffic signals in Tennessee

Journal of Traffic and Transportation Engineering(English Edition) 2023年第5期10卷 918-933页

作者： christopher Winfrey Piro Meleby Lei Miao Department of Engineering Technology Middle Tennessee State UniversityMurfreesboroTN 37132USA

This paper discusses low-cost approaches capable of ranking traffic intersections for the purpose of signal *** extracted intersections that are comprised of multiple roads,defined by alphanumeric traffic message channel segment codes per international classification *** of these road segments includes a variety of metrics,including congestion,planning time index,and bottleneck ranking information provided by the Regional Integrated Transportation Information *** first approach was to use a ranking formula to calculate intersection rankings using a score between 0 and 10 by considering data for different times of the day and different days of the week,weighting weekdays more heavily than weekends and morning and evening commute times more heavily than other times of *** second method was to utilize unsupervised machine learning algorithms,primarily k-means clustering,to accomplish the intersection ranking *** first approach this by checking the performance of basic k-means clustering on our data *** then explore the ranking problem further by utilizing data provided by traffic professionals in the state of *** exploration involves using MATLAB to minimize the mean-squared error of intersection rankings to determine the optimum weights in the ranking formula based on a city’s professional *** then attempted an optimization of our weights via a brute-force search approach to minimize the distance from ranking formula results to the clustering *** the ranking information was aggregated into an online SQL database hosted by Amazon web services that utilized the PHP scripting language.

关键词： Unsupervised machine learning Clustering k-means Traffic signals

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 mystery is solved--CatSper is the principal calcium channel activated by progesterone in human spermatozoa

引用

Asian Journal of Andrology 2011年第3期13卷 351-352页

作者： christopher LR Barratt Reproductive and Developmental Biology Maternal and Child Health Science Laboratories Centre for Oncology and Molecular Medicine Ninewells Hospital University of Dundee Dundee Scotland DD1 9SY UK

Aremarkable advance in sperm physiology has recently been published in Nature. Two groups using patch damping techniques on human sperm have solved a mystery about the sperm cell that has puzzled both andrologists and those involved in non-genomic cellular signalling for over 20 years. In these papers, Lishko1 and Strunker2 independently demonstrate that the universal characteristic effect of progesterone on sperm--a rapid influx of calcium--is via a sperm-specific channel CatSper.

关键词： Biological sciences Cancer Medical research

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

Invasion reproductive numbers for periodic epidemic models

引用

Infectious Disease Modelling 2019年第1期4卷 124-141页

作者： christopher Mitchell christopher Kribs Department of Mathematics Tarleton State UniversityStephenvilleTX 76402USA Department of Mathematics University of Texas at ArlingtonArlingtonTX 76019-0408USA

There are many cases within epidemiology where infections compete to persist within a *** studying models for such cases,one of the goals is to determine which infections can invade a population and persist when other infections are already resident within the *** reproductive numbers(IRN),which are tied to the stability of boundary endemic equilibria,can address this *** reinterpreting resident infections epidemiologically,this study extends methods for finding IRNs to periodic systems,and presents some examples which illustrate the often complex computations *** identify conditions under which a simple time-average can be used to derive IRNs,and apply the methods to examine how seasonal fluctuations in influenza incidence facilitate the year-round persistence of bacterial respiratory infections.

关键词： Mathematical epidemiology Periodic models Basic reproductive number

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

Neighboring optimal control for periodic tasks for systems with discontinuous dynamics

引用

Science China(Information Sciences) 2011年第3期54卷 653-663页

作者： ATKESON christopher G. Robotics Institute Carnegie Mellon University

We propose a trajectory-based optimal control method for periodic tasks for systems with discontinuous dynamics. A general method, dynamic programming, suffers from the problem of dimensionality. We use local models of the optimal control law to construct a local controller. We combine a parametric trajectory optimization method and differential dynamic programming (DDP) to find the optimal periodic trajectory in a periodic task. By formulating the optimal control problem with an infinite time horizon, DDP generates time-invariant local models of the optimal control law. For DDP, the value function at dynamics discontinuities is approximated by a second order Taylor series. The utility of the proposed method is evaluated using simu- lated walking control of a five-link biped robot. The results show lower torques and more robustness from the proposed controller than a PD servo controller.

关键词： trajectory optimization differential dynamic programming optimal control biped walking control

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Amalgamated gold-nanoalloys with enhanced catalytic activity for the detection of mercury ions(Hg^2+)in seawater samples

引用

Nano Research 2020年第4期13卷 989-998页

作者： Natasha Logan Claire McVey christopher Elliott Cuong Cao Institute for Global Food Security School of Biological SciencesQueens University Belfast19 Chlorine GardensBelfastBT95DLUK Material and Advanced Technologies for Healthcare Queens University Belfast18-30 Malone RoadBelfastBT95BNUK

Mercury(Hg)is extremely toxic,and continues to cause major threats to aquatic life,human health and the ***^2+mainly derives from seawater as a product of atmospheric deposition,therefore there is great demand for sensing approaches that can detect Hg^2+in seawater ***,we demonstrate that the peroxidase-mimicking activity of gold nanoparticles(AuNPs)or so-called nanozymes,can be exploited for the detection of Hg^2+ions in various water *** a high electrolyte environment,the catalytic activity for the oxidation of 3,3’,5,5’-tetramethylbenzidine(TMB)was significantly diminished due to poor stability of the *** activity was reduced by-73.7%when the NaCl concentration was higher than 1.168%,which is much lower than that of seawater(-3.5%),thus presenting its unsuitability for detecting Hg^2+in harsh water *** overcome this limitation,AuNPs were first functionalized with oligo-ethylene glycol(OEG),of which their colloidal form presented high stability in NaCl concentrations up to 20%and across a wide range of pHs from ***,the catalytic activity of OEG-AuNPs for the oxidation of TMB was strongly suppressed by the coating,but enhanced upon formation of Au-Hg *** novel finding underlies a straightforward,sensitive,and highly selective detection platform for Hg^2+in water *** approach could detect the exposure limit level for Hg^2+in drinking water(i.e.,2 ppb for tap and bottled water)as set by the United States Environmental Protection Agency(EPA)and the World Health Organization(WHO).When Hg^2+was spiked into a 3.5%saline solution and a coastal seawater certified reference material(CRM),the detection limits were found to be 10 ancM 3 ppb,respectively,which exceed the Hg^2+concentrations commonly found within seawater(-60-80 ppb).The whole procedure takes less than 45 min to conduct,providing a highly innovative,rapid and low-cost approach for detecting Hg^2+in complex water matrices.

关键词： gold nanoparticles nanozyme peroxidase-like mercury detection w ater samples seawater

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

Uterine receptivity and the plasma membrane transformation

引用

Cell Research 2004年第4期14卷 259-267页

作者： christopher R MURPHY Department of Anatomy and Histology The University of Sydney NSW 2006. Australia

This review begins with a brief commentary on the diversity of placentation mechanisms, and then goes on to examine the extensive alterations which occur in the plasma membrane of uterine epithelial cells during early pregnancy across species. Ultrastructural, biochemical and more general morphological data reveal that strikingly common phenomena occur in this plasma membrane during early pregnancy despite the diversity of placental types-from epitheliochorial to hemochorial, which ultimately form in different species. To encapsulate the concept that common morphological and molecular alterations occur across species, that they are found basolaterally as well as apically, and that moreover they are an ongoing process during much of early pregnancy, not just an event at the time attachment, the term ’plasma membrane transformation’ is suggested which also emphasises that alterations in this plasma membrane during early pregnancy are key to uterine receptivity.

关键词： uterine epeithelial cells membrane tranformation.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Hollow ion atomic structure and X-ray emission in dense hot plasmas

引用

Matter and Radiation at Extremes 2024年第6期9卷 43-52页

作者： Frank B.Rosmej christopher J.Fontes Sorbonne University Faculty of Science and EngineeringUMR 7605Case 1284 Place JussieuF-75252 ParisFrance Ecole Polytechnique LULIAtomic Physics in Dense PlasmasRoute de SaclayF-91129 PalaiseauFrance Computational Physics Division Los Alamos National LaboratoryLos AlamosNew Mexico 87545USA

Hollow ion X-ray emission is of great interest in high-energy-density research,since negligible opacity allows studies from the interior of very dense *** this paper,ionization potential depressions of the isoelectronic sequences for single and double K-shell vacancies are obtained from a pure ab initio multiconfiguration Hartree-Fock simulation including exact exchange terms and finite temperature dense plasma *** is demonstrated that the simultaneous representation of these ab initio data in the form of a map of hollow ion X-ray transition energies enables identification of important steps in the matter evolution and ionization *** along the isoelectronic sequence as a function of the pumping energy of a X-ray free electron laser also enables visualization of the impact of ionization potential depression on the pathways of hollow ion formation.

关键词： enable interior steps

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

Severe acute pancreatitis： pathogenesis, diagnosis and surgical management

引用

Hepatobiliary & Pancreatic Diseases International 2017年第2期16卷 155-159页

作者： Mark Portelli christopher David Jones Department of General Surgery University Hospital Ayr Ayr KA6 6DX UK

BACKGROUND： Severe acute pancreatitis is a subtype of acute pancreatitis, associated with multiple organ failure and systemic inflammatory response syndrome. In this qualitative review we looked at the principles of pathogenesis, classification and surgical management of severe acute pancreatitis. We also looked at the current shift in paradigm in the management of severe acute pancreatitis since the guideline developed by the British Society of *** SOURCES： Studies published between 1st January 1991 and 31st December 2015 were identified with Pub Med, MEDLINE, EMBASE and Google Scholar online search engines using the following Medical Subject Headings： “acute pancreatitis, necrosis, mortality, pathogenesis, incidence” and the terms “open necrosectomy and minimally invasive necrosectomy”.The National Institute of Clinical Excellence（NICE） Guidelines were also included in our study. Inclusion criteria for our clinical review included established guidelines, randomized controlled trials and non-randomized controlled trials with a follow-up duration of more than 6 ***： The incidence of severe acute pancreatitis within the UK is significantly rising and pathogenetic theories are still controversial. In developed countries, the most common cause is biliary calculi. The British Society of Gastroenterology,acknowledges the Revised Atlanta criteria for prediction of severity. A newer Determinant-based system has been *** principle of surgical management of acute necrotizing pancreatitis requires intensive care management, identifying infection and if indicated, debridement of any infected necrotic area. The current procedures opted for include standard surgical open necrosectomy, endoscopic necrosectomy and minimally invasive necrosectomy. The current paradigm is shifting towards a step-up ***： Severe acute pancreatitis is still a subject of grey areas in its surgical management even though new studies have been recorde

关键词： severe acute pancreatitis acute pancreatitis necrosis mortality pathogenesis incidence open necrosectomy and minimally invasive necrosectomy

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

Emerging trends in expansive soil stabilisation: A review

引用

Journal of Rock Mechanics and Geotechnical Engineering 2019年第2期11卷 423-440页

作者： Chijioke christopher Ikeagwuani Donald Chimobi Nwonu Civil Engineering Department University of Nigeria

Expansive soils are problematic due to the performances of their clay mineral constituent, which makes them exhibit the shrink-swell characteristics. The shrink-swell behaviours make expansive soils inappropriate for direct engineering application in their natural form. In an attempt to make them more feasible for construction purposes, numerous materials and techniques have been used to stabilise the soil. In this study, the additives and techniques applied for stabilising expansive soils will be focused on,with respect to their efficiency in improving the engineering properties of the soils. Then we discussed the microstructural interaction, chemical process, economic implication, nanotechnology application, as well as waste reuse and sustainability. Some issues regarding the effective application of the emerging trends in expansive soil stabilisation were presented with three categories, namely geoenvironmental,standardisation and optimisation issues. Techniques like predictive modelling and exploring methods such as reliability-based design optimisation, response surface methodology, dimensional analysis, and artificial intelligence technology were also proposed in order to ensure that expansive soil stabilisation is efficient.

关键词： Expansive soil Engineering properties Soil stabilisation Geoenvironmental issues Standardisation Optimisation

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

Tissue engineering in urethral reconstruction--an update

引用

Asian Journal of Andrology 2013年第1期15卷 89-92页

作者： Altaf Mangera christopher R Chapple Department of Urology Research Sheffield Teaching Hospitals N HS Trust Royal Hallamshire Hospital Sheffield S10 2JF U K and Sheffield Hallam University and Consultant Urological Surgeon at the Royal Hallamshire Hospital Sheffield S10 2JF UK

The field of tissue engineering is rapidly progressing. Much work has gone into developing a tissue engineered urethral graft. Current grafts, when long, can create initial donor site morbidity. In this article, we evaluate the progress made in finding a tissue engineered substitute for the human urethra. Researchers have investigated cell-free and cell-seeded grafts. We discuss different approaches to developing these grafts and review their reported successes in human studies. With further work, tissue engineered grafts may facilitate the management of lengthy urethral strictures requiring oral mucosa substitution urethroplasty.

关键词： reconstructive urology tissue engineering urethra urethroplasty

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：