There is a push to increase production of unconventional gas in Australia, which would intensify the use of the controversial technique of hydraulic fracturing. The uncertainties surrounding the health implications of unconventional gas, when considered together with doubts surrounding its greenhouse gas profile and cost, weigh heavily against proceeding with proposed future developments. The h...

[1] Estimated parameter distributions in groundwater models may contain significant uncertainties because of data insufficiency. Therefore, adaptive uncertainty reduction strategies are needed to continuously improve model accuracy by fusing new observations. In recent years, various ensemble Kalman filters have been introduced as viable tools for updating high-dimensional model parameters. How...

This paper deals with the design of a brake caliper pressure controller for a conventional ABS/ESC system and the experimental validation of its tracking performances. The analysis of the hydraulic plant, carried out in Part I of this two-part study, is here utilized to develop the control algorithm for ABS digital electro-hydraulic valves. The control strategy is based on a Feedforward (FF) an...

sures experienced by a pipeline can be either beneficial or detrimental from an operational performance perspective, depending on the amount, the two phase regime of the mixture (whether homogeneous or slug) and the nature and cause of the transient. It is generally held that when free (undissolved) air, or gas, is present in a hydraulic system, it can greatly reduce the surge pressure levels b...

The hydraulic servo control system, which is the important component of parallel robot, is a high order, nonlinear, dynamic asymmetry, parameter uncertain system, which seriously affect dynamic performance of robot, so it is very difficult to gain good performance with traditional control. Based on sliding mode variable structure control method combined with fuzzy control and adaptive control, ...

The safety assessment of Nuclear Power Plants makes use of Thermal-Hydraulic codes for the quantification of the safety margins with respect to upper/lower safety thresholds, when postulated accidental scenarios occur. To explicitly treat uncertainties in the safety margins estimates within the Risk-Informed Safety Margin Characterization (RISMC) framework, we resort to the concept of Dynamic P...

Nowadays, hydropower plays an essential role in the energy market. Due to their fast response and regulation capacity, hydraulic turbines operate at off-design conditions with a high number of starts and stops. In this situation, dynamic loads and stresses over the structure are high, registering some failures over time, especially in the runner. Therefore, it is important to know the dynamic r...

In this article, the motion control problem of hydraulic lifting systems subject to parametric uncertainties, unmodeled disturbances, and a valve dead-zone is studied. To surmount problem, an active disturbance rejection adaptive controller was developed for systems. Firstly, dynamics, including both mechanical dynamics actuator with system, were modeled. Then, by adopting system model backstep...

We describe a modification to the collapsing method, a technique that aims to find the simplest structures in a cloud of microearthquakes by utilizing the statistical uncertainties in the data. In the modified collapsing method, the movements of the locations are dependent on the shape of the distribution of the locations within the confidence ellipsoid, and not just the position of the center ...