This paper presents a model on the leverage of …nancial intermediaries, where debt are held by risk averse agents and equity by the risk neutral. The paper shows that in an unregulated competitive market, …nancial intermediaries choose to be leveraged over the social best level. This is because the leverage of one intermediary imposes a negative externality upon others by reducing their pro…t m...

There are several strategies for maintenance and repairing of devices in industry. However, they are still confronted with many uncertainties. A hydraulic lifting device after ten years of working in a technical center in Isfahan is faced with uncertainty in terms of reliability. Being able to know the reliability of pieces means predicting failure occurrences, which is accomplished by conditio...

Electro-hydraulic systems with regards to the their specific features and applications among other industrial systems including mechanical, electrical and pneumatic systems, have been widely taken into consideration by the scientists and researchers. Due to the fact that the electro-hydraulic system is inherently a nonlinear system, has some problems such as signals saturation, nonlinear effici...

This paper studies the high performance robust mo tion control of electro-hydraulic servo-systems. The dynamics of hydraulic systems are highly nonlinear and the system may be subjected to non-smooth and discontinuous nonlinearities due to directional change of valve opening, friction, and valve overlap. Aside from the nonlinear nature of hydraulic dynamics, hydraulic servo systems also have la...

This article presents the design of a robust force controller for a hydraulic actuator interacting with an uncertain environment via quantitative feedback theory (QFT). After the derivation of a realistic nonlinear differential equation model, a linearized plant transfer function is developed. The effects of nonlinearities are accounted for by describing the linearized model parameters as struc...

Besides nutrient composition, the hydraulic performance of horticultural substrates is a main issue for evaluating their quality for horticultural purposes. Their water and air capacity and their suitability for transporting water are important hydraulic quality indicators. Shrinkage and water repellency could have a negative impact on storing and transporting water and solutes. The commonly us...

Flow and sediment transport processes are different and more complex in coarse-bed rivers than in sand-bed rivers. The main goal of the present study is to evaluate different modes of sediment transport using different hydrometric and hydraulic methods, and to address the major uncertainties. Four river reaches were selected as representatives of coarse-bed rivers in the Northwest of Iran. A se...

Current research focuses on predicting and mitigating the impacts of high hydraulic loadings on centralized wastewater treatment plants (WWTPs) under wet-weather conditions. The maximum permissible inflow to WWTPs depends not only on the settleability of activated sludge in secondary settling tanks (SSTs) but also on the hydraulic behaviour of SSTs. The present study investigates the impacts of...

In impedance control of hydraulic excavators the piston position and ram force of each hydraulic cylinder for the axis control of the boom, arm, and bucket can be determined. The problem is thus how to find the control voltage applied to the servovalves to track these commands to the hydraulic systems. This paper presents analytic, simulation and experimental results for controllers that have b...