Stylus deformation calibration and scale value extraction of REVO five-axis measuring system

REVO?is a dynamic measuring head and probe system,which is designed and applied in orthogonal coordinatemeasuring machines(CMMs)to maximize measurement throughput whilst maintaining high system accuracy.A calibration approachto the stylus deformation of REVO head is proposed and the scale value of each CMM axis is separated from the limiteddata returned from the measuring system according to the application of REVO head in non-orthogonal CMM.Experimentsshow that the calibration method presented and extraction of scale value are of effectiveness and correctness.Results demonstratethat the maximum measurement error has decreased from0.2021mm to0.0009mm and the variation of scale value ofeach CMM axis is two orders lower after the stylus deformation is compensated.

Intelligent Vehicular Communication Using Vulnerability Scoring Based Routing Protocol

Internet of Vehicles(IoV)is an intelligent vehicular technology that allows vehicles to communicate with each other via internet.Communications and the Internet of Things(IoT)enable cutting-edge technologies including such self-driving cars.In the existing systems,there is a maximum communication delay while transmitting the messages.The proposed system uses hybrid Cooperative,Vehicular Communication Management Framework called CAMINO(CA).Further it uses,energy efficient fast message routing protocol with Common Vulnerability Scoring System(CVSS)methodology for improving the communication delay,throughput.It improves security while transmitting the messages through networks.In this research,we present a unique intelligent vehicular infrastructure communication management framework.This framework includes additional stability for both short and long-range mobile communications.It also includes built-in cooperative intelligent transport system(C-ITS)capabilities for experimental verification in real-world contexts.In addition,an energy efficient-fast message distribution routing protocol(EE-FMDRP)has been presented.This combines the benefits between both temporal and direction oriented routing methods.This has been suggested for distributing information from the origin ends to the predetermined objective in a quick,accurate,and effective manner in the event of an emergency.The critical value scale score(CVSS)employ ratings to measure the assault probability in Markov chains.Probabilities of chained transitions allow us to statistically evaluate the integrity of a group of IoVassets.Thus the proposed method helps to enhance the vehicular systems.The CAMINO with energy efficient fast protocol using CVSS(CA-EEFP-CVSS)method outperforms in terms of shortest transmission latency achieves 2.6 sec,highest throughput 11.6%,and lowest energy usage 17%and PDR 95.78%.

THE SYMMETRIC POSITIVE SOLUTIONS OF 2n-ORDER BOUNDARY VALUE PROBLEMS ON TIME SCALES

In this paper, we are concerned with the symmetric positive solutions of a 2n-order boundary value problems on time scales. By using induction principle,the symmetric form of the Green＇s function is established. In order to construct a necessary and sufficient condition for the existence result, the method of iterative technique will be used. As an application, an example is given to illustrate our main result.

The nature of friction: A critical assessment

Friction is an essential part of human experience.We need traction to walk,stand,work,and drive.At the same time,we need energy to overcome the resistance to motion,hence,too much friction costs excess energy to perform work,introducing inefficiencies.In the 21st century,we are facing the dual challenges of energy shortage and global warming from burning fossil fuels.Therefore,the ability to control friction has become a top priority in our world today.Yet our understanding of the fundamental nature of friction is still lacking.Friction has always been a subject of curiosity.Intensive study of the origin of friction began in the 16th century,after the pioneering work by Leonardo da Vinci.Yet progress in understanding the nature of friction has been slow,hampered by the lack of instrument to measure friction precisely.Ingenious experiments performed by Amontons,Coulomb,and others have yielded important insights to build the foundation of our understanding.Beginning in the late 1800s and early 1900s,the advent of steam engines,locomotives,followed by the automobiles airplanes,and space exploration demands a clear understanding of friction and the ability to control it for the machinery to last.Significant progress on how to apply and control friction in engineering friction was made through trial and error.At the beginning of the 21st century,a new dimension of nanoscale friction came into the picture in conjunction with the arrival of nanotechnology.Our understanding of atomic and molecular friction has been expanding rapidly.However,integration of the new found knowledge of nanofriction into engineering practices has been elusive.Why?What is the scaling relationship between atomic friction and macro-friction?Is it possible to predict friction at the macro-level from nanoscale results?Why nanofriction values often do not agree with the macrofriction values given the same materials pair?Could it be there is a length scale dependent characteristic friction value?In engineering practice,progress since the 1980s has been slow.Most of the effort has been focused on lubrication research such as elastohydrodynamic theories and solid lubricants.Friction mechanisms and failures have received relative little attention while nanofriction received much of the attention.Today,energy efficiency and renewable energy generation demand our immediate attention while we seek reduction in carbon emission.The ability to control friction becomes an essential step in seeking sustainable technologies.Friction,after all,is an indicator of energy efficiency.If we can reduce the unnecessary parasitic energy losses and increase our current energy efficiency,it will give us time to develop alternative energy sources.This paper examines our current understanding of friction,filling some voids with experimental data,and attempts to integrate the various pieces to identify the gaps of our knowledge,hopefully to spark new avenues of investigations into this important area.