A Novel Sensor System for Measuring Wheel Loads of Vehicles on Highways
With the development of the highway transportation and business trade, vehicle Weigh-In-Motion (WIM) technology has become a key technology for measuring traffic loads. In this paper a novel WIM system based on monitoring of pavement strain responses in rigid pavement was investigated. In this WIM system multiple low cost, light weight, small volume and high accuracy embedded concrete strain sensors were used as WIM sensors to measure rigid pavement strain responses. In order to verify the feasibility of the method, a system prototype based on multiple sensors was designed and deployed on a relatively busy freeway. Field calibration and tests were performed with known two-axle truck wheel loads and the measurement errors were calculated based on the static weights measured with a static weighbridge. This enables the weights of other vehicles to be calculated from the calibration constant. Calibration and test results for individual sensors or three-sensor fusions are both provided. Repeatability, sources of error, and weight accuracy are discussed. Successful results showed that the proposed method was feasible and proven to have a high accuracy. Furthermore, a sample mean approach using multiple fused individual sensors could provide better performance compared to individual sensors.
An Accuracy Tunable Non-Boolean Co-Processor Using Coupled Nano-Oscillators
As we enter an era witnessing the closer end of Dennard scaling, where further reduction in power supply-voltage to reduce power consumption becomes more challenging in conventional systems, a goal of developing a system capable of performing large computations with minimal area and power overheads needs more optimization aspects. A rigorous exploration of alternate computing techniques, which can mitigate the limitations of Complementary Metal-Oxide Semiconductor (CMOS) technology scaling and conventional Boolean systems, is imperative. Reflecting on these lines of thought, in this article we explore the potential of non-Boolean computing employing nano-oscillators for performing varied functions. We use a two coupled nano-oscillator as our basic computational model and propose an architecture for a non-Boolean coupled oscillator based co-processor capable of executing certain functions that are commonly used across a variety of approximate application domains. The proposed architecture includes an accuracy tunable knob, which can be tuned by the programmer at runtime. The functionality of the proposed co-processor is verified using a soft coupled oscillator model based on Kuramoto oscillators. The article also demonstrates how real-world applications such as Vector Quantization, Digit Recognition, Structural Health Monitoring, and the like, can be deployed on the proposed model. The proposed co-processor architecture is generic in nature and can be implemented using any of the existing modern day nano-oscillator technologies such as Resonant Body Transistors (RBTs), Spin-Torque Nano-Oscillators (STNOs), and Metal-Insulator Transition (MITs) . In this article, we perform a validation of the proposed architecture using the HyperField Effect Transistor (FET) technology-based coupled oscillators, which provide improvements of up to 3.5× increase in clock speed and up to 10.75× and 14.12× reduction in area and power consumption, respectively, as compared to a conventional Boolean CMOS accelerator executing the same functions.
TRANSFORMED FIELD DOMAIN ANALYSIS OF PAVEMENTS SUBJECTED TO MOVING DYNAMIC TANDEM-AXLE LOADS AND INTEGRATING THEIR EFFECTS INTO THE CRCP-10 PROGRAM
The dynamic displacement and stress responses of rigid and flexible pavements subjected to moving tandem-axle loads of constant amplitude and harmonic and arbitrary variations have been investigated. The pavement systems have been modeled using a plate of infinite extent on a viscoelastic foundation. Formulations have been developed in the transformed field domain using: (1) a double Fourier transform in space and moving space for moving loads of constant amplitude; (2) a triple Fourier transform in time, space, and moving space for moving loads of arbitrary variation; and (3) a double Fourier transform in space and moving space for the steady-state response to moving harmonic loads. The effects of viscous damping, vehicle speed, load frequency, and phase between front- and rear-axle loads have been investigated. The analysis results considering viscoelasticity show significant differences from those obtained with an elastic system. The pavement surface roughness causes dynamic variations in the load amplitude, and the maximum deflection and stress can significantly increase accordingly. The variation in the load amplitude and the differences in the phase angles between front- and rear-axle loads can make the maximum deflection and stress considerably larger. The use of tandem axle loads is necessary to find the accurate responses because the phase effect cannot be considered with single-axle loads. The formulations developed to find the wheel load stresses resulting from the moving tandem-axle loads have been integrated into CRCP-10, which is the updated computer program of CRCP-9.