Now showing items 2441-2460 of 3360

    • Real-Time Modeling for Navigation and Hydropower in the River Mosel 

      Thomas Ackermann; Daniel P. Loucks; Dirk Schwanenberg; Michael Detering (American Society of Civil Engineers, 2000)
      This paper describes the development and implementation of a modeling approach using both nonlinear optimization and finite-element simulation to improve the control of river reach water levels for navigation and hydroelectric ...
    • Sampling Design for Network Model Calibration Using Genetic Algorithms 

      Roger W. Meier; Brian D. Barkdoll (American Society of Civil Engineers, 2000)
      Today, most municipal water utilities use computerized numerical models of their distribution networks. These models must be calibrated to the physical system if they are to provide accurate results. Calibration entails ...
    • Long Time-Series Simulation of Water Quality in Distribution Systems 

      Benjamin L. Harding; Thomas M. Walski (American Society of Civil Engineers, 2000)
      Dynamic (extended period simulation) models have largely replaced steady-state models for simulation of water quality in distribution networks. Dynamic modeling generally has been limited to periods of a day or a few days. ...
    • Leak Detection and Calibration Using Transients and Genetic Algorithms 

      John P. Vítkovský; Angus R. Simpson; Martin F. Lambert (American Society of Civil Engineers, 2000)
      Leak detection and calibration of pipe internal roughnesses in a water distribution network are significant issues for water authorities around the world. Computer simulation of water distribution systems to determine the ...
    • Optimization of Regional Water Distribution System with Blending Requirements 

      Shu-li Yang; Yung-Hsin Sun; William W-G. Yeh (American Society of Civil Engineers, 2000)
      In a multisource, multiquality regional water distribution system, water agencies often find that it is necessary to impose blending requirements at certain control points in the system in order to secure the desired water ...
    • Multiobjective Management of Potomac River Consumptive Use 

      Stuart S. Schwartz (American Society of Civil Engineers, 2000)
      Multiobjective systems analysis is used to size reservoir storage and identify noninferior system operating rules that mitigate the impacts of consumptive appropriations. The marginal impacts of consumptive use are offset ...
    • Editorial 

      Curtis B. Barrett (American Society of Civil Engineers, 2000)
    • Velocity Profiles and Unsteady Pipe Friction in Transient Flow 

      Bruno Brunone; Bryan W. Karney; Michele Mecarelli; Marco Ferrante (American Society of Civil Engineers, 2000)
      Transient conditions in closed conduits have traditionally been modeled as 1D flows with the implicit assumption that velocity profile and friction losses can be accurately predicted using equivalent 1D velocities. Although ...
    • Integrating Yield and Shortage Management under Multiple Uncertainties 

      Marion W. Jenkins; Jay R. Lund (American Society of Civil Engineers, 2000)
      An economic-engineering modeling approach is presented for integrating urban water supply reliability analysis with shortage management options such as dry year option and spot market water transfers, water reuse, and long- ...
    • Constraint Handling for Genetic Algorithms in Optimal Remediation Design 

      Amy B. Chan Hilton; Teresa B. Culver (American Society of Civil Engineers, 2000)
      There often is difficulty enforcing the given constraints when applying a genetic algorithm (a flexible stochastic search method) to optimal ground-water remediation design problems. This paper compares two methods for ...
    • Editorial 

      Uri Shamir; Charles D. D. Howard (American Society of Civil Engineers, 2000)
    • Comparison of ANNs and Empirical Approaches for Predicting Watershed Runoff 

      Jagadeesh Anmala; Bin Zhang; Rao S. Govindaraju (American Society of Civil Engineers, 2000)
      Prediction of watershed runoff resulting from precipitation events is of great interest to hydrologists. The nonlinear response of a watershed (in terms of runoff) to rainfall events makes the problem very complicated. In ...
    • Accuracy of Neural Network Approximators in Simulation-Optimization 

      Virginia M. Johnson; Leah L. Rogers (American Society of Civil Engineers, 2000)
      Heuristic search techniques are highly flexible but computationally intensive optimization methods that require hundreds, sometimes thousands, of evaluations of the objective function to reach termination criteria in common ...
    • Efficient and Equitable Impact Fees for Urban Water Systems 

      Istvan Lippai; James P. Heaney (American Society of Civil Engineers, 2000)
      An efficient and equitable method for determination of impact fees for urban water systems is presented. A fair allocation of costs is based on
    • Short-Term Operation Model for Coupled Hydropower Reservoirs 

      Ramesh S. V. Teegavarapu; Slobodan P. Simonovic (American Society of Civil Engineers, 2000)
      A short-term operation model is developed for optimal operation of hydraulically coupled hydropower plants. The model uses mixed integer nonlinear programming as an optimization tool. An innovative method is proposed to ...
    • Neural Network-Based Simulation-Optimization Model for Reservoir Operation 

      T. R. Neelakantan; N. V. Pundarikanthan (American Society of Civil Engineers, 2000)
      There have been several attempts to use combined simulation-optimization models to solve reservoir operation problems efficiently. In many cases, complex simulation models are available, but direct incorporation of them ...
    • EXPLORE—Hybrid Expert System for Water Networks Management 

      Carlos León; Sergio Martín; José M. Elena; Joaquín Luque (American Society of Civil Engineers, 2000)
      A hybrid expert system called EXPLORE has been developed to manage the Seville City water-supply system. The main difficulties are the lack of information on management procedures, the complicated electrical tariff, the ...
    • Linear Programming for Flood Control in the Iowa and Des Moines Rivers 

      Jason T. Needham; David W. Watkins Jr.; Jay R. Lund; S. K. Nanda (American Society of Civil Engineers, 2000)
      This study addresses questions related to flood-control operating procedures followed by the U.S. Army Corps of Engineers, Rock Island District. Application is presented of a mixed integer linear programming model for a ...
    • Dynamic Models for Floodplain Management 

      J. Rolf Olsen; Peter A. Beling; James H. Lambert (American Society of Civil Engineers, 2000)
      A dynamic model of floodplain management is shown to address nonstationary conditions, including land-use changes, channel modifications, economic development, and climate change and variability. The dynamic approach permits ...
    • Statewide Non-Point-Source Pollution Assessment Methodology 

      W. Cully Hession; Maeve McBride; Mark Bennett (American Society of Civil Engineers, 2000)
      We present a new methodology for performing Virginia's statewide, watershed-level non-point-source pollution assessment. The problems and inconsistencies inherent in previous methodologies were addressed and improved upon. ...