We present a new two-parameter expression for relative hydraulic conductivity (RHC) of partially saturated soils. It is based on the premise of Assouline et al. [1998] that soil structures evolve from a uniform random fragmentation process. This assumption allows us to derive hydraulic properties of soils (water retention curves and unsaturated hydraulic conductivity) from primary properties, s...

This paper reports on an investigation of the possible influence of modelling errors on the relationship between the entropy and hydraulic reliability of water distribution systems. The errors are due to minor differences between the design optimisation and subsequent simulation models, which lead to small discrepancies between the capacity of the network and the required supply. Pressure-depen...

This paper focuses on optimal hydraulic component selection for electrohydraulic systems used in high performance servo tasks. Dynamic models of low complexity are proposed that describe the salient dynamics of basic electrohydraulic equipment. Rigid body equations of motion, the hydraulic dynamics and typical trajectory inputs are used in conjunction with optimization techniques, to yield an o...

This paper examines the effect of friction model on the simulation accuracy of a hydraulic cylinder by using three friction models: a steady-state friction model, the LuGre model, and the new modified LuGre model. Hydraulic cylinder’s behaviors were measured under sinusoidal input to the servo valve. Simulations were conducted under the same conditions as the experiments. The comparisons of sim...

Large-scale hydrological models are important decision support tools in water resources management. The largest source of uncertainty in such models is the hydrostratigraphic model. Geometry and configuration of hydrogeological units are often poorly determined from hydrogeological data alone. Due to sparse sampling in space, lithological borehole logs may overlook structures that are important...