Many engineering tasks involve the search for good solutions among many possibilities. In most cases, tasks are too complex to be modeled completely and their solution spaces often contain local minima. Therefore, classical optimization techniques cannot, in general, be applied effectively. This paper studies two stochastic search methods, one well-established ~simulated annealing! and one rece...

A discretization of the continuous Kalinin-Milyukov-Nash-cascade is performed with the help of state-space analysis for hydrological forecasting of streamflow. A sample-data system approach is used during the discretization and results in discretely coincident values with the continuous model. The sample-data system uses input values measured instantly in time and assumes linear changes in the ...

The 2003 flood of the Muda River reached 1,340 m3 /s at Ladang Victoria and adversely impacted 45,000 people in Malaysia. A flood control remediation plan proposed a levee height based on a 50-year discharge of 1 ,815 m3 /s obtained from hydrologic models. This design discharge falls outside the 95% confidence intervals of the flood frequency analysis based on field measurements. Instream sand ...

This paper presents analytical estimates of the behavior exhibited by curved, archlike structures under radially directed and gravitational line loads. The behavior is shown to range from elementary beam bending at one end to a state of pure compression at the other, and its behavior can be tracked by an arch rise parameter that is a function of the arch’s semivertex angle, radius and thickness...

A least-squares method is used to determine the fundamental parameters of a simple mathematical model for the mechanical subsystem of the NEES-UCSD large high performance outdoor shaking table. The parameters identified include the effective horizontal mass, the effective horizontal stiffness, and the coefficient of the classical Coulomb friction and viscous damping elements representing the va...

Stochastic optimization is used to estimate the willingness-to-pay WTP of individual households and groups of households for changes in a combination of probabilistic water supply reliability and retail price of water. By modeling the financial and “perceived” costs of implementing longand short-term conservation options and assuming rational expected value cost minimizing behavior, economic de...

In the existing approach to maintenance and repair decision making for infrastructure facilities, policy evaluation and policy selection are performed under the assumption that a perfect facility deterioration model is available. The writer formulates the problem of developing maintenance and repair policies as a reinforcement learning problem in order to address this limitation. The writer exp...

Electromagnetic wave surface velocimeters ESVs measure the Doppler shift in electromagnetic waves reflected from the water surface. They provide nonintrusive water surface velocity measurements from bridges and river banks. Comparisons with laboratory and field tests show very good agreement over a wide range of elevation and planview angles. Laboratory testing shows comparable results between ...

Interaction between a jet and its neighbors in a still ambient fluid is dealt with. A model for the merging of an infinite line of equally spaced identical jets in a still ambient fluid is developed. The velocity and tracer distributions in the model are determined based on the summation of momentum fluxes and tracer fluxes, respectively. Laser-induced fluorescence experiments are conducted for...

This paper addresses the integrated design of civil engineering structures with control systems. Simultaneous optimization of such controlled structures is considered, showing that new alternative solutions can be achieved through integrated design. A procedure for design of controlled structural systems is developed using a two-stage approach: 1 a design of an optimal control system using a li...