The transverse profilograph has been recognized as one of the most accurate devices for the measurement of rut depth. However, interpretation of surface transverse profile measurements poses a major challenge in deter...
详细信息
The transverse profilograph has been recognized as one of the most accurate devices for the measurement of rut depth. However, interpretation of surface transverse profile measurements poses a major challenge in determining the contributions of the different layers to rutting. A literature review has shown that the actual rutting mechanism can be estimated from a surface transverse profile for determination of the relative contribution of the layers to rutting. Unfortunately, much of the research yielded no verification or data. In addition, some techniques presented cannot be used if the rut depth is not well pronounced. Other techniques may be costly and time-consuming. The present research developed an approach that integrates (a) falling weight deflectometer and core data along with 3.6-m transverse profile measurements to assess the contributions of different pavement layers to rutting and (b) identifies the presence (or absence) of instability within the asphalt surface layer. This approach can be used regardless of the magnitude of the rut depth. On the basis of the analysis conducted, absolute rut depth should not be used to interpret the performance of the asphalt mixture. In addition, continued instability may not result in an increase in rut depth because the rutted basin broadens as traffic wander compacts or moves the dilated portion of the mixture. The approach developed appears to provide a reasonable way to distinguish between different sources of rutting. The conclusions drawn from analysis of the approach agreed well with observations from the trench cuts taken from four sections.
The integration of decentralized renewable energy sources leads to a changed load profile of electrical power engineering utilities such as generators, transformers etc. A decreased application of thermal power plants...
详细信息
ISBN:
(纸本)9781999815691
The integration of decentralized renewable energy sources leads to a changed load profile of electrical power engineering utilities such as generators, transformers etc. A decreased application of thermal power plants as primary supply of electrical energy results in progressive energy transition and rising load dynamics. Frequent start-up processes etc. lead to rapid changes in the operation conditions of large turbine generators and increasing thermo-mechanical and mechanical stress of the involved devices. The electrical insulation system of high-voltage engineering components is a common reason for destructive failure. To improve the reliability of electrical energy supply and to estimate the expected lifetime of power engineering devices, especially in consideration of increasing stress the complex nature of multi-stress insulation ageing has to be investigated.
We consider the problem of convex constrained minimization of an average of n functions, where the parameter and the features are related through inner products. We focus on second order batch updates, where the curva...
详细信息
ISBN:
(纸本)9781509052936
We consider the problem of convex constrained minimization of an average of n functions, where the parameter and the features are related through inner products. We focus on second order batch updates, where the curvature matrix is obtained by assuming random design and by applying the celebrated Stein's lemma together with subsampling techniques. The proposed algorithm enjoys fast convergence rates similar to the Newton method, yet the per-iteration cost has the same order of magnitude as the gradient descent. We demonstrate its performance on well-known optimization problems where Stein's lemma is not directly applicable, such as M-estimation for robust statistics, and inequality form linear/quadratic programming etc. Under certain assumptions, we show that the constrained optimization algorithm attains a composite convergence rate that is initially quadratic and asymptotically linear. We validate its performance through widely encountered optimization tasks on several real and synthetic datasets by comparing it to classical optimization algorithms.
The properties responsible for electrical contact resistance between a stainless steel bipolar plate and a carbon support in a PEFC has been investigated. Roughness of the bipolar plate is useful but its topography sh...
详细信息
We address the problem of simulating domestic activities related to electrical consumption. Continuously growing electrical energy requirements have become an issue as resources to produce it are limited. Human factor...
详细信息
ISBN:
(纸本)9781479987146
We address the problem of simulating domestic activities related to electrical consumption. Continuously growing electrical energy requirements have become an issue as resources to produce it are limited. Human factors have to be taken into account in order to better predict electric consumption and optimize its production. We propose a framework based on a psychological scheme and on stochastic features. The decision process is based on the representation of habits and the use of heat maps. Inclusion of planning-related behavior is performed by a non-parametric voting method using relational properties among domestic activities. The results show a good fitting between the predictions and ground truth.
Because of the advantages of being reliable, saving weight, size and cost, reducing maintenance fees and environmental impact, More Electric Aircraft (MEA) has attracted more and more attention, and Electro-mechanical...
详细信息
A design methodology for sequential logic circuits using controllable flip-flops is proposed. The flip-flop setup time and propagation delay is controlled with a process, voltage and temperature (PVT) detector using a...
详细信息
A design methodology for sequential logic circuits using controllable flip-flops is proposed. The flip-flop setup time and propagation delay is controlled with a process, voltage and temperature (PVT) detector using an additional setup time and delay control (SDC) input. With this SDC enable, it is possible to enhance the circuit timing performance when PVT variations are detected. The PVT detector is based in the propagation delay of digital buffers. When an increase in the propagation delay is detected in the digital logic, the SDC flip-flop input is enabled to reduce its setup time and Clk-Q propagation delay. When the PVT conditions are maintained under the selected threshold, the SDC control remains disabled, saving power. The proposed flip-flop and PVT detector are designed and characterized in a TSMC 28 nm bulk CMOS technology.
暂无评论