Measuring Characteristics of the Fastest Commercially-Available Digitizers

Measurements of the dynamic performance of eight different digitizers are presented and analysed to show the types and magnitudes of error to which each digitizer is prone. The impact of these errors on the measurements of fast single-shot transients, such as front chopped impulses with times-to-chopping in the range of 500 ns (the fastest covered by the standards) to a few ns, is examined. The suitable range of application of each digitizer is deduced.     

The Warsaw district heating system

In Warsaw, Poland, the capacity of the heat-generating power plants in 1982 was 4352 MW and the length of the network was 1187 km. This paper describes the development of this district heating system over the last 30 years. Figures show cross-sections of main ducts and tunnels.     

A formal semantics for concurrent systems with a priority relation

Summary A formal semantics for the COSY path expressions with a priority relation is proposed. It turns out that in the general case the full aspects of behaviours of systems specified by such expressions cannot be modeled by vector firing sequences (a standard semantics for the case without priorities), although vector firing sequences (but without interpretation as causality relations) can correctly be extended for expressions with priorities, and some (but not all) aspects of behaviours, like deadlockfreeness and adaquacy properties, can be defined in terms of vector firing sequences. To describe the behaviours of the COSY priority path expressions entirely, a new semantics, called the multiple firing sequence semantics, is introduced and some its properties are proved.Main part of this work was done during the author's visit at the Institute of Electronic Systems, Aalborg University Centre, Aalborg, DenmarkOn leave from the Warsaw Technical University, Poland     

Studies of heterogeneous isotope exchange of Cd (II) between the solution and the surface layer formed on aluminium oxide and activated carbon

The dependence of the isotope exchange kinetic curves on $\text{I∞}\text{I}{}_{\mathrm{o}}$ is studied, where I_∞ denotes the equilibrium activity and I_o is the initial activity of the solution. Experimental kinetic curves of isotope exchange of Cd (II) ions between the bulk solution and the surface layer formed on aluminium oxide and activated carbon (charcoal) are compared with theoretical calculations.     

Intelligent evolutionary design: A new approach to optimizing complex engineering systems and its application to designing heat exchangers

A new method for optimizing complex engineering designs is presented that is based on the Learnable Evolution Model (LEM), a recently developed form of non‐Darwinian evolutionary computation. Unlike conventional Darwinian‐type methods that execute an unguided evolutionary process, the proposed method, called LEMd, guides the evolutionary design process using a combination of two methods, one involving computational intelligence and the other involving encoded expert knowledge. Specifically, LEMd integrates two modes of operation, Learning Mode and Probing Mode. Learning Mode applies a machine learning program to create new designs through hypothesis generation and instantiation, whereas Probing Mode creates them by applying expert‐suggested design modification operators tailored to the specific design problem. The LEMd method has been used to implement two initial systems, ISHED1 and ISCOD1, specialized for the optimization of evaporators and condensers in cooling systems, respectively. The designs produced by these systems matched or exceeded in performance the best designs developed by human experts. These promising results and the generality of the presented method suggest that LEMd offers a powerful new tool for optimizing complex engineering systems. © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 1217–1248, 2006.