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In shaft-less drive gravure printing machines, each gravure printing roller is driven by an individual servo motor. The register accuracy is an important performance indicator for gravure printing process, and it is based on the stability and accuracy of the web tension between the printing rollers. Therefore, the mathematical model of the web tension between two adjacent printing rollers is studied...
Vertically-aligned multiwall carbon nanotubes were deposited on silicon substrate by low pressure chemical vapor deposition (LPCVD), which can be utilized as heat spreaders in high power electronic packaging due to their remarkable thermal conductivity. The infrared emissivity of the vertically aligned multiwall carbon nanotubes was then characterized based on the FLIR SC600 infrared imaging system...
Graphene-based films (GBF) were fabricated using a chemical conversion process including graphene oxide (GO) preparation by use of Hummer's method, graphene oxide reduction using L-ascorbic acid (LAA), and finally film formation by vacuum filtration. GBF is considered as a candidate material for thermal management, i.e. for removing heat from hotspots in power electronic packaging, due to its high...
Thermal interface material (TIM) is applied to fill the air gaps of interfaces, which provides a path for interfacial heat transfer. Owing to the exceptional thermal properties of carbon nanotubes (CNT), TIMs based on CNTs have received much attention in recent years. In this study, heat dissipation performance of vertically aligned carbon nanotubes (VACNT) arrays as TIM in electronic packing was...
High-resolution bathymetric sidescan sonar system (HRBSSS) is a kind of acoustic detection equipment for the micro-topography of the seafloor. This paper briefly introduces the working principle, the main error sources, the data processing and error calibration method of HRBSSS at first. On this basis, a sounding data quality assessment method including one part for the sonar and the other for the...
MANET (mobile ad hoc network) technology has become increasingly attractive for real-world applications in the past decade. Dynamic and intermittent connectivity caused by node mobility poses a huge challenge to the operation of MANETs that require end-to-end paths for communication. The attacks against critical nodes could result in a more degraded network service. In this paper, we evaluate the...
K0.5Na0.5NbO3 (KNN) ceramics is considered as one of the most promising candidates for lead free piezoelectric ceramics, because of its high Curie temperature and good electrical properties. However, it is well known that dense and well-sintered KNN ceramics are very difficult to obtain because of the high volatility of alkali elements at high temperatures. According to some references, the molar...
With the rapid advancement of wireless technology and the exponential increase of wireless devices in the past decades, there are more consumer applications for MANETs (mobile ad hoc networks) in addition to the traditional military uses. A resilient and robust MANET is essential to high service quality for applications. The dynamically changing topologies of MANETs pose a huge challenge to normal...
Understanding network behavior under challenges is essential to constructing a resilient and survivable network. Due to the mobility and wireless channel properties, it is more difficult to model and analyze MANETs (mobile ad hoc networks) under various challenges. Previously, we have modeled network attacks based on a priori complete knowledge of network structure and mobility. In this paper, we...
The optical fiber sensing technology has been rapidly applied in manufacturing and industrial fields. In this paper, a diaphragm-type fiber Bragg grating (FBG) sensor used for detecting the static/dynamic pressure of gas or liquid, is designed and experimentally studied. The pressure sensitivity of the sensor is obtained from both analytical solution and simulation calculation using finite element...
Aiming at the evaluate problem of electrical actuating system health status, a method based on grey target theory is proposed for the health status assessment of electromechanical actuating system. The fault condition index model is built by using grey target theory, and a quantitative classification problem of the health status is solved by using wavelet packet-grey neural network in the condition...
To improve the motion accuracy of servo feed system and aim at solving the problem that conventional methods for optimization of the servo control parameters mainly depend on manual tuning and cannot achieve optimal configuration of servo control parameters. A novel improved genetic algorithm is proposed to optimize the servo control parameters. An adaptive crossover, mutation strategy and elitism...
In order to understand the role of critical nodes in mobile ad hoc networks (MANETs), dynamic topologies are modelled as time-varying graphs and network topologies within a certain time window are aggregated as a weighted static graph. Critical node behaviour has been previously studied by evaluating how end-to-end throughput is impacted by the removal of high centrality nodes. However, different...
This paper presents the horizontal control of a novel magnetic suspension stage (MSS) whose travel range is 0.8 mm×0.8 mm in the X and Y axes. Firstly, the dynamic model of MSS in the horizontal is built. And then, based on the three degree-of-freedom (DOF) dynamic model, a decoupling fuzzy sliding mode controller is designed. Finally, planar positioning experiments show that the presented controller...
Due to the tremendous potential of MANETs (mobile ad hoc networks) for deployment in commercial and military services, a thorough understanding of network behaviour when exposed to challenges is essential for constructing a resilient and survivable MANET. Therefore, it is vital to have a comprehensive framework that can model it under various network attacks and challenges. The MANET environment has...
This work investigates the effect of the pole-arc width on the cogging torque of the permanent magnet motors based on the assumption of distributed force instead of the previous concentrated one. On the basis of the motors' mechanical and electrical symmetry, the superposition method is employed to examine the above effect. And the phase tuning relationships between the pole-arc width and the cogging...
Exposure to high temperature environments can result in the decay of fiber Bragg grating (FBG). In this paper, thermal regenerated fiber Bragg grating has been fabricated through conventional hydrogen loading FBG. The highest sustainable temperature of the grating is more than 800℃. The results of calibration experiments show that in the range of -60℃ to700℃the variation of Bragg wavelength fits quadratic...
Fiber Bragg gratings (FBGs) were fabricated in Sn-doped single mode quartz fiber by UV exposure through phase mask. Linearity and repeatability of the FBGs were studied at temperature from 25 °C to 600 °C. The results of the study showed that linearity of the FBGs by high temperature heat treatment was better than that of sensor without standing heat treatment, and its linear correlation coefficient...
This paper analyzes the 21 original geometric errors of machine tools and the resulting coupling effects, namely geometric composite errors, and then arrives at the conclusion that the key point of error compensation for CNC machine tools is error value, a function of command position. And it also points the errors can be decoupled into error components of each axis-direction. Therefore, according...
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