Frequency domain solution to delay-type Nehari problem

This paper generalizes the frequency-domain results on the delay-type Nehari problem in the stable case to the unstable case. The solvability condition of the delay-type Nehari problem is formulated in terms of the nonsingularity of three matrices. The optimal value γ_opt is the maximal γ∈(0,∞) such that one of the three matrices becomes singular. All sub-optimal compensators are parameterized in a transparent structure incorporating a modified Smith predictor.     

EM procedures using mean field-like approximations for Markov model-based image segmentation

Image segmentation using Markov random fields involves parameter estimation in hidden Markov models for which the EM algorithm is widely used. In practice, difficulties arise due to the dependence structure in the models and approximations are required. Using ideas from the mean field approximation principle, we propose a class of EM-like algorithms in which the computation reduces to dealing with systems of independent variables. Within this class, the simulated field algorithm is a new stochastic algorithm which appears to be the most promising for its good performance and speed, on synthetic and real image experiments.     

Determination of vitality from a non-invasive biomedical measurement for use in fingerprint scanners

Fingerprints are the oldest and most widely used biometrics for personal identification. Unfortunately, it is usually possible to deceive automatic fingerprint identification systems by presenting a well-duplicated synthetic or dismembered finger. This paper introduces one method to provide fingerprint vitality authentication in order to solve this problem. Detection of a perspiration pattern over the fingertip skin identifies the vitality of a fingerprint. Mapping the two-dimensional fingerprint images into one-dimensional signals, two ensembles of measures, namely static and dynamic measures, are derived for classification. Static patterns as well as temporal changes in dielectric mosaic structure of the skin, caused by perspiration, demonstrate themselves in these signals. Using these measures, this algorithm quantifies the sweating pattern and makes a final decision about vitality of the fingerprint by a neural network trained by examples.     

Wave propagation by the passage of two high-speed trains in a tunnel

A numerical simulation of unsteady compressible flow induced by two high-speed trains in oncoming traffic within a tunnel is presented. The computations were carried out by means of a second-order accurate Harten-Yee type upwind TVD scheme. In order to take the effect of friction into account, a source term is included in the governing flow equations. In the computation, moving boundary configurations were used to simulate the two trains passing through the tunnel. As geometrical configuration, the Einmalberg tunnel, where experimental data are available, was selected. The computational results agree reasonably well with their experimental counter-part. The waves interaction and the waves propagation process at the tunnel entrance and exit as well as within the tunnel are addressed. Finally, the influence on the transmitted waves at the tunnel exit portal and the variation of the negative pressure drop during the passage of the two trains are discussed.     

Systemised serendipity for producing computer art

Serendipity applied to Newton's method, and its derivative the Secant Method, produces unusual and beautiful fractal patterns. Serendipity may be systemised, for example, by the introduction of a perturbation parameter P1, [1] to facilitate searches for interesting pattern variations.     

Role of early supervisory experience in supervisor performance.

Explores the role of early supervisory experience and cognitive ability in 1st-line supervisor performance. Similar to the F. L. Schmidt et al (see record 1986-31441-001) study of nonsupervisors, this research tested structural models hypothesizing relationships among supervisory experience, cognitive ability, supervisory knowledge and proficiency, and performance ratings, using a sample of 570 2nd-tour soldiers. The Schmidt et al model with an additional ability?→?experience path provided the best fit. The significant ability?→?experience path was interpreted as indicating that demonstrated ability contributes to soldiers being given the opportunity to obtain supervisory experience. Experience had a greater impact on supervisor proficiency than on supervisor knowledge. Ability had a greater impact on supervisor knowledge than on proficiency. Discussion focuses on the personal characteristics that might be involved in being assigned supervisory responsibilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Object-extending class transformations

Reorganisation and evolution of class hierarchies is important for object-oriented system development and has received considerable attention in the literature. The contributions of this paper are: (1) a formal study of a set of extension relations and transformations on class hierarchies; (2) a presentation of a small set of primitive transformations which form a minimal and complete basis for the extension relations; and (3) an analysis of the impact of these transformations at the object level.The study leads to a better understanding of evolution and reuse of object-oriented software and class hierarchies. It also provides a terminology and a means of classification for design reuse. The theory presented in this paper is based on the Demeter data model, which gives a concise mathematical foundation for classes and their inheritance and part-of relationships. Parts of the theory have been implemented in the Demeter System ^TM C++, a CASE tool for object-oriented design and programming.