The classical Kalman filter (KF) is an effective approach of state estimation for linear discrete-time systems, but classical KF is applicable only when external inputs are measured. So far, some studies of Kalman filter with unknown inputs (KF-UI) have been proposed. However, previous KF-UI approaches based solely on acceleration measurements are inherently unstable which leads to poor trackin...

This paper presents a procedure to design reinforced concrete (RC) buildings achieve an acceptable target level of earthquake-induced loss (e.g., deaths, dollars, downtime) under site-specific hazard profile. The is called “direct” since the specified at first step process, and virtually no iteration required. based on simplified assessment involving surrogate model for seismic demand (i.e., pr...

Design of reinforced concrete (RC) buildings with a direct-displacement-based design (DDBD) method has been used extensively for the last few decades around world. As compared to force-based (FBD) method, DDBD provides advantages in cost-reduction, construction timing, and better structural performance. This paper investigates methodology G + 3 storied RC buildings, having different configurati...

A novel ultrasonic steel horn with a Bézier profile is developed. The first longitudinal displacement mode of the horn is exploited for high displacement amplification. An optimization scheme and finite element analyses are used to design the horn. The displacement amplification and stress distribution characteristics of the Bézier horn and catenoidal horn are examined. Prototypes of the horns ...

An enhanced displacement feedback structural control procedure is presented for performance-based design in this paper. At first, a comparative study is implemented assessing three most common active control algorithms including state, acceleration, and displacement feedback controls. The advantage of the displacement feedback algorithm for active control of structures against earthquakes is de...

in this paper, a new algorithm for studying elastic wave propagation in the phononic crystals is presented. at first, the displacement-based forms of elastic wave equations are derived and then the forms are discretized using finite difference method. so the new algorithm is called the displacement-based finite difference time domain (dbfdtd). three numerical examples are computed with this met...

This paper presents a novel method for modifying the shapes of existing uniform bi-cubic B-spline surfaces by interactively editing the curvatures along isoparametric curves. The method allows us to edit the curvatures of the two intersecting isoparametric curves at each knot with specified positions, unit tangents, and unit normals. The user adjusts the radii of circles, representing the radii...