The principal aim of cognitive networking is to equip traditional networks with some sort of intelligence, in order to make them evolve and achieve higher levels of performance than those that can currently be achieved . Typical characteristics of cognitive networks are the ability to monitor the environment they are deployed in, to take reasoned actions based on current conditions towards an end-to-end objective, and to learn from past experience. Such enhanced networks will likely be characterized by a nonnegligible complexity, which can be tolerated if accompanied by relevant benefits, such as performance increase or mitigation of management burden. Different cognitive proposals have been proposed thus far in the literature, ranging from general framework definitions , to cognitive node architectures , to specific implementations . This contribution aims to illustrate the concepts we advanced in previous works , in which we described how the cognitive networking paradigm can fill the gap between service-oriented architectures and network, and extend them, by enabling reasoning with external information, i.e. information that is not locally available and is sensed elsewhere in the network. This enables the cognitive process to achieve a global vision of the network, which should facilitate the achievement of better end-to-end performance.

The interactions between the design of a computer's instruction set and the design of compilers that generate code for that computer have serious implications for overall computational cost and efficiency. This article, which investigates those interactions, should ideally be based on comprehensive data; unfortunately, there is a paucity of such information. And while there is data on the use of instruction sets, the relation of this data to compiler design is lacking. This is, therefore, a frankly personal statement, but one which is based on extensive experience. My colleagues and I are in the midst ofa research effort aimed at automating the construction of productionquality compilers. (To limit the scope of what is already an ambitious project, we have considered only algebraic languages and conventional computers.) In brief, unlike many compiler- compiler efforts of the past, ours involves automatically generating all of the phases of a compiler-including the optimization and code generation phases found in optimizing compilers. The only input to this generation process is a formal definition of the source language and target computer. The formulation of compilation algorithms that, with suitable parameters, are effective across a broad class of computer architectures has been fundamental to this research. In turn, finding these algorithms has led us to critically examine many architectures and the problems they pose. Much of the opinion that follows is based on our experiences in trying to do this, with notes on the difficulties we encountered.

In this study the geometrical optimization of monolithically integrated solar cells into serially connected solar modules is reported. Based on the experimental determination of electrodes0 sheet and intermittent contact resistances, the overall series resistance of individual solar cells andinterconnected solar modules is calculated. Taking a constant photocurrent generation density into account, the total Joule respectively resistive power losses are determined by a self-consistent simulation according to the 1-diode model. This method allows optimization of the solar module geometry depending on the material system applied. As an example, polymer solar modules based on ITO-electrodes and ITO-free electrodes were optimized with respect to structuring dimensions.