Characteristics of MOBILE4 and EMFAC7E Models
Several recent studies (e.g., Lawson et al., 1990; Ingalls, 1989) have indicated that the EPA and ARB vehicle emission factor models MOBILE4 and EMFAC7E underpredict in-use vehicle emission...
Modeling Guideline for Air Quality Analysis of Intersections
Model evaluations have been performed testing eight different models for the ability to estimate carbon monoxide near intersections. These evaluation results along with the need for updated...
Developing Protocols for Motor Vehicle Air Quality Modeling
This paper is directed to air quality analysts. It examines the issues surrounding a modeling protocol and how to work effectively with a traffic engineer on a project to model carbon...
Integrating Traffic and Air Quality Modeling Techniques to Predict Pollutant Concentrations Near Intersections
Many cities are considering transportation management measures and/or tailpipe emission controls to reduce the pollution associated with traffic congestion. A major difficulty is the expensive...
Integrated Assessment of Environmental Risk and Human Response
Meaningful risk assessment for environmental problems requires an integrated consideration of physical science and human behavioral issues. This is particularly true when dissaggregate...
Quantitative Risk Assessment and Technology Transfer: Software Developments
A risk-based adaptation of the hydroeconomic model for estimating the expected annual damages of floods is presented in a spreadsheet environment. The model demonstrates how commercially...
Optimal Flood Warning Threshold: A Case Study in Connellsville, Pennsylvania
A methodology for selecting an optimal flood-warning threshold has been developed by Haimes et al. (1990). The probabilistic evaluation of a forecast system coupled with a stochastic dynamic...
Optimal Discretization of Random Fields for SFEM
A new method for discretization of random fields (representation in terms of random variables) is introduced based on the principle of optimal linear estimation theory. The method is more...
Application of the Sampling Theorem to the Representation of Random Fields
A new parametric model is developed for homogeneous Gaussian random fields based on a generalization of the sampling theorem. The model depends linearly on a finite set of discrete values...
Pseudo-Simulation Method for Stochastic Problems
A new numerical method for problems of stochastic mechanics and other areas involving a small number of random parameters is presented. It is analogous to the Monte-Carlo simulation method...
Reliability Analysis of Uncertain Systems Under Random Loadings
This study considers the reliability assessment of uncertain systems under random loadings. The fast integration method (Wen and Chen, 1987) in conjunction with a second order asymptotic...
Stochastic Dynamics of Hysteretic Systems
A frequency domain method is discussed in order to evaluate the second order statistical response of nonlinear hysteretic structures. Both shear type systems and lumped mass frames involving...
A Coordinate Reduction Technique With Mass Correction for Dynamic Analysis of Structural Systems
A more accurate technique which can be applied for reducing the order of system matrices when employing the finite element method (FEM) is presented. Unlike traditional reduction techniques,...
A Selective MC Simulation Technique for Nonlinear Structural Reliability Assessment
A selective Monte Carlo simulation (MCS) procedure for the evaluation of the reliability of nonlinear structures subjected to dynamic random loading is presented. The proposed 'double...
Use of Importance Sampling Constraints in System Optimization
An important application of system reliability analysis is to incorporate overall system risk as a constraint in a structural optimization. The paper describes the use of Monte Carlo Importance...
Updating of Dynamic Structural Systems by Learning
Many techniques have been developed to identify structural system parameters; however, they are generally restricted to parameter identification within the framework of an equivalent structure...
Dynamic Response of Uncertain Two-Dimensional Structures
A concept for the reliability analysis of structures with uncertain elastic and mass properties is presented. Its applicability is shown by means of a numerical example. The results are...
Vibration of a Bridge Under a Random Train of Moving Loads
The vibration of a beam resulting from the passage of moving loads is a problem of great importance in structural dynamics. A consistent model for the description of the loads acting on...
Surface Motion Due to Stochastic Plane Sources in a Layered Medium
To simulate the ground motion in the near field, a seismic fault is modeled as a two-strip plane. The width of each strip is so thin that the rupture process of the strip can be described...
Linear System Spectral Moments Determination
The stationary response of a linear system to random excitation is considered. A previously developed approach is extended to be applicable for the determination of both even and odd order...
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