Support for virtual states and deltas between them is useful for a variety of database applications, including hypothetical database access, version management, simulation, and active databases. The Heraclitus paradigm elevates delta values to be \\rst-class citizens" in database programming languages, so that they can be explicitly created, accessed and manipulated. A fundamental issue concern...

changes in dynamic properties of structures indicate occurrence of damages in the structures. in this paper, a new two stage algorithm for damage detection of large structure is introduced. a modified residual force method is utilized to locate the damage regions in structures, especially barrel vaults, and then the enhanced charged system search (css) algorithm is used to quantify the amount o...

latticed columns are frequently used in industrial steel structures. in some countries these built-up columns might be even used in other types of steel structures such as residential and commercial buildings. besides, latticed columns are parts of skeletons of many historic buildings all around the world. to analyze a steel structure with latticed columns a more accurate numerical model for su...

Fitting response surface models is usually carried out using statistical packages to solve complicated equations in order to produce the estimates of the model coefficients. This paper proposes a new procedure for fitting response surface models to mixed two-level and four-level factorial designs. New and easier formulae are suggested to calculate the linear, quadratic and the interaction coeff...

in this paper a new optical channel drop filter (cdf) based on two dimensional (2-d) photonic crystals (phc) with hexagonal shaped structure is proposed and numerically demonstrated by using the finite-difference-time-domain (fdtd) and plane-wave-expansion (pwe) techniques. photonic crystals (phcs) are artificial dielectric nanostructure materials in which a periodic modulation of the material ...