检索结果-南通市图书馆

Ricochet quantification using a multiple sensor approach

Defence Technology（防务技术） 2021年第2期17卷 305-314页

作者： michael Muster Amer Hameed David Wood Centre for Defence Engineering Cranfield UniversityDefence Academy of the United KingdomShrivenhamSN68LAUK

This study investigates the ricochet behaviour of three different small-arms projectile types using a novel ricochet measuring *** results can be used to estimate the danger potential of ricochets on shooting ranges.A ricochet is the change of direction and velocity of a projectile after impacting an oblique *** impact produces strong vibrations on a rigid *** this impact,flexural waves travel radially outwards from the point of *** waves are used to determine the properties of the impactor with accelerometers situated on the target *** the use of two measurement plates,one can produce a ricochet and detect the velocity at the same *** are suitable for accurate momentum measurements of single ***,depending upon strike velocity and the impact angle,a ricochet can separate in multiple fragments after being *** the operational safety perspective,these fragments need to be detected,as *** approach of a coupled sensor concept was chosen to solve this *** sensors were additionally used to visualise the heat which is produced after penetrating a rubber layer pasted in front of the steel target *** this approach one was able to detect the position of *** investigations showed that the measurement system performance is better with a multiple sensor design,which includes accelerometers for the velocity,impact strength and partly the position measurement,while the thermographic sensor was used for the position measurement and partly the momentum *** investigated ammunition showed plausible fragmentation behaviour,and the results can already be used to estimate the danger potential of different ammunition *** projectiles fragment to small particles already after being deflected under a small ***,Full Metal Jacket projectiles with or without a steel core do not fragment under angles which are less than 5.The objective of the pa

关键词： Ricochet analysis Small-calibre ammunition Velocity measurement Thermography

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

Value of incorporating geospatial information into the prediction of on-street parking occupancy - A case study

引用

Geo-Spatial Information Science 2021年第3期24卷 438-457页

作者： michael Balmer Robert Weibel Haosheng Huang Department of Geography University of ZurichZurichSwitzerland Department of Geography Ghent UniversityGhentBelgium

In light of growing urban traffic,car parking becomes increasingly critical for cities to *** a result,the prediction of parking occupancy has sparked significant research interest in recent *** many external data sources have been considered in the prediction models,the underlying geographic context has mostly been ***,in order to study the contribution of geospatial information to parking occupancy prediction models,road network centrality,land use,and Point of Interest(POI)data were incorporated in Random Forest(RF)and Artificial Neural Network(ANN,specifically Feedforward Neural Network FFNN)prediction models in this *** performances were compared to a baseline,which only considers historical and temporal input ***,the influence of the amount of training data,the prediction horizon,and the spatial variation of the prediction were *** results show that the inclusion of geospatial information led to a performance improvement of up to 25%compared to the ***,as the prediction horizon expanded,predictions became less reliable,while the relevance of geospatial data *** general,land use and POI data proved to be more beneficial than road network *** amount of training data did not have a significant influence on the performance of the RF *** ANN model,conversely,achieved optimal results on a training input of 5 *** attributable to varying occupancy patterns,prediction performance disparities could be identified for different parking districts and street ***,the RF model outperformed the ANN model on all predictions.

关键词： Parking occupancy prediction on-street parking geospatial information machine learning

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

Machines as readers: A solution to the copyright problem

引用

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2005年第11期6卷 1179-1187页

作者： SHAMOS michael I. School of Computer Science Carnegie Mellon University Pittsburgh PA 15213 USA Department of Computer Science University of Hong Kong Hong Kong China

Copyright and its international complications have presented a significant barrier to the Universal Digital Library （UDL）＇s mission to digitize all the published works of mankind and make them available throughout the world. We discuss the effect of existing copyright treaties and various proposals, such as compulsory licensing and the public lending fight that would allow access to copyrighted works without requiring permission of their owners. We argue that these schemes are ineffective for purposes of the UDL. Instead, making use of the international consensus that copyright does not protect facts, information or processes, we propose to scan works digitally to extract their intellectual content, and then generate by machine synthetic works that capture this content, and then translate the generated works automatically into multiple languages and distribute them free of copyright restriction.

关键词： Universal Digital Library (UDL) Copyright Digital rights management Compulsory license Berne convention Public lending right Synthetic documents Machine translation

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 insect cellular immune response

引用

Insect Science 2008年第1期15卷 1-14页

作者： michael R. Strand Department of Entomology and Center for Emerging and Tropical Global Diseases University of Georgia Athens Georgia USA

The innate immune system of insects is divided into humoral defenses that include the production of soluble effector molecules and cellular defenses like phagocytosis and encapsulation that are mediated by hemocytes. This review summarizes current understand- ing of the cellular immune response. Insects produce several terminally differentiated types of hemocytes that are distinguished by morphology, molecular and antigenic markers, and function. The differentiated hemocytes that circulate in larval or nymphal stage insects arise from two sources： progenitor cells produced during embryogenesis and mesodermally derived hematopoietic organs. Regulation of hematopoiesis and hemocyte differentiation also involves several different signaling pathways. Phagocytosis and encapsulation require that hemocytes first recognize a given target as foreign followed by activation of downstream signaling and effector responses. A number of humoral and cellular receptors have been identified that recognize different microbes and multicellular parasites. In turn, activation of these receptors stimulates a number of signaling pathways that regulate different hemocyte functions. Recent studies also identify hemocytes as important sources Of a number of humoral effector molecules required for killing different foreign invaders.

关键词： antimicrobial peptides clotting cytokines Diptera Drosophila encapsulation,hemocytes immunity insects Lepidoptera nodulation phagocytosis

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

OPTIMAL CONTROL OF THE LAPLACE-BELTRAMI OPERATOR ON COMPACT SURFACES： CONCEPT AND NUMERICAL TREATMENT

引用

Journal of Computational Mathematics 2012年第4期30卷 392-403页

作者： michael Hinze Morten Vierling Schwerpunkt Optimierung und Approximation Universit~it Hamburg Bundesstrafle 55 20146 Hamburg Germany

We consider optimal control problems of elliptic PDEs on hypersurfaces F in R^n for n = 2, 3. The leading part of the PDE is given by the Laplace-Beltrami operator, which is discretized by finite elements on a polyhedral approximation of F. The discrete optimal control problem is formulated on the approximating surface and is solved numerically with a semi-smooth Newton algorithm. We derive optimal a priori error estimates for problems including control constraints and provide numerical examples confirming our analytical findings.

关键词： Elliptic optimal control problem Laplace-Beltrami operator Surfaces Controlconstraints Error estimates Semi-smooth Newton method.

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

FINITE ELEMENT EXTERIOR CALCULUS FOR PARABOLIC EVOLUTION PROBLEMS ON RIEMANNIAN HYPERSURFACES

引用

Journal of Computational Mathematics 2018年第6期36卷 792-832页

作者： michael Hoist Christopher Tiee Department of Mathematics University of California San Diego La Jolla CA 92093 USA

Over the last ten years, Finite Element Exterior Calculus （FEEC） has been developed as a general framework for linear mixed variational problems, their numerical approximation by mixed methods, and their error analysis. The basic approach in FEEC, pioneered by Arnold, Falk, and Winther in two seminal articles in 2006 and 2010, interprets these problems in the setting of Hilbert complexes, leading to a more general and complete understanding. Over the last five years, the FEEC framework has been extended to a broader set of problems. One such extension, due to Hoist and Stern in 2012, was to problems with variational crimes, allowing for the analysis and numerical approximation of linear and geometric elliptic partial differential equations oil Riemannian manifolds of arbitrary spatial dimension. Their results substantially generalize the existing surface finite element approximation theory in several respects. In 2014, Gillette, Hoist, and Zhu extended FEEC in another direction, namely to parabolic and hyperbolic evolution systems by combining the FEEC framework for elliptic operators with classical approaches for parabolic and hyperbolic operators, by viewing solutions to the evolution problem as lying in Bochner spaces （spaces of Banach-space valued parametrized curves）. Related work on developing an FEEC theory for parabolic evolution problems has also been done independently by Arnold and Chen. In this article, we extend the work of Gillette-Holst- Zhu and Arnold-Chen to evolution problems on Riemannian manifolds, through tile use of framework developed by Holst and Stern for analyzing variational crimes. We establish a priori error estimates that reduce to the results from earlier work in tile flat （non-criminal） setting. Some numerical examples are also presented.

关键词： FEEC Elliptic equations Evolution equations Approximation theory Inf-supconditions A priori estimates Variational crimes Equations on manifolds

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

Shades of Chaos: Lessons Learned About Lessons Learned About Forecasting El Nio and Its Impacts

引用

International Journal of Disaster Risk Science 2015年第1期6卷 94-103页

作者： michael H.Glantz Consortium for Capacity Building (CCB) Institute of Arctic and Alpine Research (INSTAAR) University of Colorado

The troubled forecast of El Nio’s onset in2014 requires an explanation as well as an open dialogue with the user community that depends on such an important forecast. A review of the forecasts on the Internet reflects two different perceptions about what transpired. The forecast community suggests they got it right, while the popular media suggests forecasters got it wrong. Why such a gap? The major El Nio that was alluded to by several organizations did not materialize when or even as expected. A science-fed media frenzy took place about an event considered in retrospect to have been an unusual borderline(weak) El Nio event, 'trickiest ever to forecast.'That is understandable, as the science of El Nio is still on a learning curve. But it suggests that the forecasting of El Nio’s onset is still in an experimental phase and not yet operational. Forecasting its onset(as a specific event)should be separated from forecasting its behavior and impacts(as a process) once the onset has been *** a forecast is made, someone is responding to ***, such a distinction is necessary for the benefit of those societies and economic sectors affected by El Nio.

关键词： 2014 El Nio forecast El Nio ENSO Experimental forecast Oscillations Teleconnections

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

Combining Human and Rodent Genetics to Identify New Analgesics

引用

Neuroscience Bulletin 2018年第1期34卷 143-155页

作者： Alban Latremoliere michael Costigan Kirby Neurobiology Center Boston Children's Hospital and Department of Neurobiology Harvard Medical School Department of Anesthesiology Perioperative and Pain Medicine Boston Children's Hospital

Most attempts at rational development of new analgesics have failed, in part because chronic pain involves multiple processes that remain poorly understood. To improve translational success, one strategy is to select novel targets for which there is proof of clinical relevance, either genetically through heritable traits, or pharmacolog- ically. Such an approach by definition yields targets with high clinical validity. The biology of these targets can be elucidated in animal models before returning to the patients with a refined therapeutic. For optimal treatment, having biomarkers of drug action available is also a plus. Here we describe a case study in rational drug design： the use of controlled inhibition of peripheral tetrahydrobiopterin （BH4） synthesis to reduce abnormal chronic pain states without altering nociceptive-protective pain. Initially iden- tified in a population of patients with low back pain, the association between BH4 production and chronic pain has been confirmed in more than 12 independent cohorts, through a common haplotype （present in 25% of Cau- casians） of the rate-limiting enzyme for BH4 synthesis, GTP cyclohydrolase 1 （GCH1）. Genetic tools in mice have demonstrated that both injured sensory neurons and activated macrophages engage increased BH4 synthesis to cause chronic pain. GCH1 is an obligate enzyme for de novo BH4 production. Therefore, inhibiting GCH1 activity eliminates all BH4 production, affecting the synthesis of multiple neurotransmitters and signaling molecules and interfering with physiological function. In contrast, target- ing the last enzyme of the BH4 synthesis pathway, sepiapterin reductase （SPR）, allows reduction of patholog- ical BH4 production without completely blocking physio- logical BH4 synthesis. Systemic SPR inhibition in mice has not revealed any safety concerns to date, and available genetic and pharmacologic data suggest similar responses in humans. Finally, because it is present in vivo only when SPR is inhi

关键词： Chronic pain Genetics Mouse models Tetrahydrobiopterin Sepiapterin reductase Analgesics

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

On the critical behavior of a homopolymer model

引用

Science China Mathematics 2019年第8期62卷 1463-1476页

作者： michael Cranston Stanislav Molchanov Department of Mathematics University of California at Irvine Irvine CA 92697-3875 USA Department of Mathematics The University of North Carolina Charlotte NC 28223 USA

We begin with the reference measure P0 induced by simple, symmetric nearest neighbor continuous time random walk on Zd starting at 0 with jump rate 2d and then define, for β≥0, t > 0, the Gibbs probability measure Pβ,t by specifying its density with respect to P0 as dPβ,t/dP0= Zβ,t（0）(-1eβ∫0tδ0（xs）ds),（0.1）where Zβ,t（0）≡E0[eβ∫t0δ0（xs）ds]. This Gibbs probability measure provides a simple model for a homopolymer with an attractive potential at the origin. In a previous paper（Cranston and Molchanov, 2007）, we showed that for dimensions d≥3 there is a phase transition in the behavior of these paths from the diffusive behavior for β below a critical parameter to the positive recurrent behavior for β above this critical value. The critical value was determined by means of the spectral properties of the operator ? + βδ0, where ? is the discrete Laplacian on Zd. This corresponds to a transition from a diffusive or stretched-out phase to a globular phase for the polymer. In this paper we give a description of the polymer at the critical value where the phase transition takes place. The behavior at the critical parameter is dimension-dependent.

关键词： Gibbs measure homopolymer phase transition globular phase diffusive phase

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

Challenges and perspectives for structural biology of IncRNAs-the example of the Xist IncRNA A-repeats

引用

Journal of Molecular Cell Biology 2019年第10期11卷 845-859页

作者： Alisha NJones michael Sattler Institute of Structural Biology Helmholtz Zentrum MunchenNeuherberg85764Germany Center for Integrated Protein Scienee Munich and Bavarian NMR Center at Department of Chemistry Technical University of MunichGarching85747Germany

Following the discovery of numerous long non-coding RNA(IncRNA)transcripts in the human genome,their important roles in biology and human disease are *** progress in experimental methods has enabled the identification of structural features of ***,determining high-resolution structures is challenging as IncRNAs are expected to be dynamic and adopt multiple conformations,which may be modulated by interaction with protein binding *** X-inactive specific transcript(Xist)is necessary for X inactivation during dosage compensation in female placental mammals and one of the beststudied *** progress has provided new insights into the domain organization,molecular features,and RNA binding proteins that interact with distinct regions of *** A-repeats located at the 5'end of the transcript are of particular interest as they are essential for mediating silencing ofthe inactive X ***,we discuss recent progress with elucidating structural features of the Xist IncRNA,focusing on the *** discuss the experimental and computational approaches employed that have led to distinct structural models,likely reflecting the intrinsic dynamics of this *** presence of multiple dynamic conformations may also play an important role in the formation ofthe associated RNPs,thus influencing the molecular mechanism underlying the biological function of the Xist *** propose that integrative approaches that combine biochemical experiments and high-resolution structural biology in vitro with chemical probing and functional studies in vivo are required to unravel the molecular mechanisms of IncRNAs.

关键词： In cRNA structural biology Xist chemical pro bing enzymatic footpri nting computational structure predicti on

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：