Online Activation and Deactivation of a Petri Net Supervisor

This paper highlights algebraic and mathematical properties in symmetry with Petri nets in order to control automated systems such as flexible workshops, which represent one of the most important examples in industry and for discrete event systems in general. This project deals with the problem of forbidden state transition by using a new application of the theory of regions for supervisory control. In the literature, most control synthesis methods suffer greatly from a cumbersome calculation burden of the Petri net supervisor given the complex exploration of the state graph. Our new methodology lightens the computational load of the Petri net supervisor by choosing specific regions on the reachability graph, on which the control is calculated offline using CPLEX. The determined controller is activated online if the process enters the chosen region, and deactivated otherwise. All our experiments were applied in a flexible workshop implemented in our research laboratory, which was used to engrave selected models on glass blocks of different colors.

New Computational Geometry Methods Applied to Solve Complex Problems of Radiative Transfer

Diverse problems of radiative transfer remain as yet unsolved due to the difficulties of the calculations involved, especially if the intervening shapes are geometrically complex. The main goal of our investigation in this domain is to convert the equations that were previously derived into a graphical interface based on the projected solid-angle principle. Such a procedure is now feasible by virtue of several widely diffused programs for Algorithms Aided Design (AAD). Accuracy and reliability of the process is controlled in the basic examples by means of subroutines from the analytical software DianaX, developed at an earlier stage by the authors, though mainly oriented to closed cuboidal or curved volumes. With this innovative approach, the often cumbersome calculation procedure of lighting, thermal or even acoustic energy exchange can be simplified and made available for the neophyte, with the undeniable advantage of reduced computer time.

PROCEDURE OF MULTICRITERION CHOICE IN PERSONNEL MANAGEMENT

The paper considers the methodology for multi-criteria selection in personnel management and, in particular, in the process of evaluating alternatives in the search and selection of high-quality staff. As well, the systems interaction of criteria in assessment of choosing alternatives noted by M. Sugeno is taken into account. Due to the fact that multiple criteria naturally come as a result of analysis of the operation purpose, in practice not all criteria of an optimization problem equally interact. The purpose of the operation is decomposed into a number of subgoals, where each subgoal induces its own system of criteria, evaluating the degree of its achievement for each alternative choice. Since the criteria serve to assess the degree of achievement of a common subgoal, than, on the one hand, it is natural to expect their interaction. On the other hand, the absence of interaction with the criteria of other subsets can be assumed. In this regard, an individual fuzzy measure of criteria values was introduced to display the interaction of criteria. A general fuzzy measure is constructed as an additive union of private measures. A scalarization indicator structure was chosen to use the constructed fuzzy measure for a reasonable assessment and ranking of alternatives, taking into account the system interaction of the criteria. M. Sugeno proposed a fuzzy integral as a scalarized construction, which allows us to obtain the desired scalar estimate. The disadvantage of this formula, in addition to the rather cumbersome calculation algorithm, is that it directly applies only to normalized criteria. An alternative structure of a scalarizing indicator is introduced to extend the applicability of the method and in cases where “natural” criteria are used. The considered methodology can be recommended as a means of decision support in personnel management.

Design and Realization of Management System for University Sports Scores

We adopt rapid prototyping method to develop the system, depend on the rapid prototyping creation tool to achieve the design and implementation of management system of university sports scores, aim at simplifying the calculation and statistics of sports scores, realize the informatization management, and deliver the cumbersome calculation and statistics work to computer to accomplish automatically.

A Numerical Methodology to Predict Exhaust Plumes of Propulsion Nozzles

A simple methodology to simulate the mixing layers that occur between nozzle exhaust jet and the external air is proposed. The method is based on a simplified model of the plume, that replaces the mixing layer with a contact discontinuity surface, thus avoiding the cumbersome calculation of the turbulent mixing of two flows with different chemical composition. The contact discontinuity is numerically treated by an advanced fitting technique, capable of tracking the discontinuity by points floating over the computational grid. The numerical method is discussed and its capability is demonstrated with validation tests, as well as with a discussion of some practical applications for underexpanded nozzle flows.