This paper discusses a measurement-based approach to dependability evaluation of fault-tolerant, real-time software systems based on failure data collected from stability tests of an air traffic control system under development. Several dependability analysis techniques are illustrated with the data: parameter estimation, availability modeling of software from the task level, applications of th...

The stability of a delay differential equation can be investigated on the basis of the root location of the characteristic function. Though a number of stability criteria are available, they usually do not provide any information about the characteristic root with maximal real part, which is useful in justifying the stability and in understanding the system performances. Because the characteris...

The spatial and temporal stability of soil test values is important to the use of soil testing for nutrient management. A study was conducted to evaluate the spatial and temporal stability of soil test phosphorus (P). Five sites ranging in size fiom 9.1 to 10.8 acres were soil sampled in the same locations in a 60 X 60 ft. grid either three or four times over a two year period. Bray 1 -P values...

Agile software development methods are used extensively in the software industry. This paper describes an argument to explain why these methods can be used within a multi-disciplinary project and provides a concrete description on how to implement such a method, using a case-study to support the rationale. The SOFIE (Intelligent Assisted Bicycle) project was created to develop mechatronic appli...

In this paper, a method based on some test signal (Test Signal Method) is developed to find the dominant oscillating frequencies and dampings associated with any generator in the system. The method can be realized easily by time domain simulation using electromechanical transient programs. The theoretical background of the test signal method is the theory of mechanical admittance and mode ident...

The main objective of this paper is twofold. First, we devise a stability test for determining whether a linear retarded fractional delay differential system has no characteristic roots in a specified right half of the complex plane. Second, we develop a practical method for computing the abscissa of stability (defined as the largest of the real parts of the characteristic roots) for this type ...

The paper proposes a new stability test for two-dimensional (2D) discrete systems. It is a tabular test; that is, it builds for the tested bivariate polynomial of degree (n1, n2) a sequence of n2 (or n1) bivariate polynomials or matrices (the “2D table”) of increasing row and decreasing column sizes. It is an immittance-type test, which means that it uses a three-term recurrence relation to obt...

The changes in the stability of a system of linear differential delay equations resulting from the delay are studied by analyzing the associated eigenvalues of the characteristic equation. A specific contour is mapped by the characteristic equation into the complex plane to give an easy test for stability from an application of the argument principle. When the real part of an eigenvalue is posi...

OBJECTIVE The purpose of the present experiment was to determine the reliability of the cervicocephalic relocation test (CRT). METHODOLOGY Thirteen young healthy adults were recruited to undergo a CRT test-retest. The test-retest reliability was determined by repeatedly measuring CR to a neutral position after active movement, with trials approximately 1 hour apart. Each CRT involved 20 CRs t...