When massaging differential-algebraic equations during an index reduction process, one usually keeps track of structural zeros in order to be able to detect when non-differential equations appear. However, in a numerical setting structural zeros may turn out as small numbers, impossible to distinguish from zero when numerical precision is taken into account. Such coefficients are referred to as...

an_eul is a new automatic method for simultaneous approximation of location, depth, and structural index (geometry) of magnetic sources. in the 2d case analytic signal is defined as a conjugate function whose imaginary part is the hilbert transform of its real part. since the first vertical derivative of the magnetic field is the hilbert transform of its horizontal derivative, vertical and hori...

A linear, aeroelastic analysis of a low aspect ratio swept back trapezoidal wing modeled as a cantilever plate is presented. An analytical and numerical formulation for both the aerodynamic forcing and structural response of the wing was developed. The analytical model uses a three dimensional time domain vortex lattice aerodynamic method. A Rayleigh-Ritz approach has been used to transfer equa...

Ecological systems are commonly studied by very concrete conventional models or very abstract random matrix models. Here we review and extend the approach of generalized structural kinetic modeling, that offers an intermediate way between these extremes. Generalized models describe systems with a specific structure, but do not restrict the processes in the model to specific functional forms. Th...

Critiques of the concept of key success factors have raised objections both conceptually and methodologically. From the latter perspective, common research practice is criticized for neglecting the influence of firm-specific, unobservable variables (e.g., management skills). To control for these effects a structural equation approach (“LISREL”) to the analysis of panel data is proposed. In an e...

Most commonly used second-order-accurate, dissipative time integration algorithms for structural dynamics possess a spurious root. For an algorithm to be accurate, it has been suggested that the spurious root must be small and ideally be zero in the low-frequency limit. In the paper we show that good accuracy can be achieved even if the spurious root does not tend towards zero in the low-freque...