Self-adaptive systems: A survey of current approaches,research challenges and applications

Self-adaptive software is capable of evaluating and changing its own behavior, whenever the evaluation shows that the software is not accomplishing what it was intended to do, or when better functionality or performance may be possible. The topic of system adaptivity has been widely studied since the mid-60s and, over the past decade, several application areas and technologies relating to self-adaptivity have assumed greater importance. In all these initiatives, software has become the common element that introduces self-adaptability. Thus, the investigation of systematic software engineering approaches is necessary, in order to develop self-adaptive systems that may ideally be applied across multiple domains. The main goal of this study is to review recent progress on self-adaptivity from the standpoint of computer sciences and cybernetics, based on the analysis of state-of-the-art approaches reported in the literature. This review provides an over-arching, integrated view of computer science and software engineering foundations. Moreover, various methods and techniques currently applied in the design of self-adaptive systems are analyzed, as well as some European research initiatives and projects. Finally, the main bottlenecks for the effective application of self-adaptive technology, as well as a set of key research issues on this topic, are precisely identified, in order to overcome current constraints on the effective application of self-adaptivity in its emerging areas of application.     

Guest-host interactions in zeolites as studied by NMR spectroscopy: implications in synthesis,catalysis and separations

The intermolecular forces between occluded organic molecules and the atoms that bound the pores of zeolite structures determine the catalytic activity and diffusivity of the guest molecules. These organic-inorganic forces are also a crucial aspect of the process of structure-direction in zeolite synthesis. A molecular understanding of guest-host interactions can often be deduced by using NMR spectroscopy to study the rotational motion of the occluded molecules. This contribution is an overview of systems where NMR, particularly deuterium NMR, has been used to quantify the forces which exist between occluded organic molecules and the zeolite structure. Systems that are relevant to synthesis, separations, and catalysis are discussed. The works presented show that NMR is a powerful tool for studying guest-host interactions in zeolitic materials. A molecular level understanding of the nature and relative importance of the various forces discussed should lead to a more rational basis for the selection and development of zeolitic materials used in catalytic and adsorption applications. This revised version was published online in August 2006 with corrections to the Cover Date.     

The discovery of hidden facial images in the paintings of Vincent Van Gogh and Paul Gauguin by using computer graphics enhancement techniques

For nine short weeks in 1888, Vincent Van Gogh and Paul Gauguin lived and worked together in the city of Arles. Using computer graphics enhancement analyses, some of the paintings they did during this period revealed hidden facial images. One full hidden figure in a painting by Van Gogh and five camouflaged facial images in the works of Paul Gauguin were uncovered using computer graphics techniques. With the exception of one painting by Gauguin, these concealed images have not been previously reported.     

Simultaneous degradation of atrazine and simazine by a binary culture of Stenotrophomonas maltophilia and Arthrobacter sp. in a two‐stage biofilm reactor

BACKGROUND: The impact of mixtures of chloro‐triazinic herbicides, such as atrazine and simazine, on aquatic ecosystems is of environmental concern. To study their biodegradation under various operational conditions, a binary community comprising Stenotrophomonas maltophilia and Arthrobacter sp. attached to the porous support of a packed bed reactor, was evaluated. RESULTS: The genetic analysis of the two atrazine‐degrading strains revealed that genes atzA, atzB, atzC are present in both bacteria, but only S. maltophilia possess atzD. Thus, by cultivating Arthrobacter sp. on these herbicides, cyanuric acid accumulation was observed. When the binary community was cultivated in the biofilm reactor, at all the loading rates probed, both herbicides were entirely removed. However, complete biodegradation of cyanuric acid was not achieved. CONCLUSIONS: Even with a two‐stage reactor, cyanuric acid was only partially removed. This fact could be attributed to the absence, in the second stage, of an easily degradable energy source, required by S. maltophilia for the uptake and cometabolic degradation of the recalcitrant heterocyclic ring. Responding to differences in nutritional conditions prevailing at each reactor stage, local differences in species' predominance were clearly detected by microbiological and molecular biology methods. Copyright © 2010 Society of Chemical Industry     

A Bayesian alternative to parametric hypothesis testing

Summary A unified approach to parametric hypothesis testing from a decision-theoretical viewpoint is proposed. A measure of the discrepancy between two models is incorporated as part of the utility function. Specifically, the Kullback logarithmic divergence is considered as such a measure. Under certain conditions, when using this measure of discrepancy there is correspondence with the classical solutions.     

Holz als Rohstoff der Weltwirtschaft

Zusammenfassung Neue Verwendungsgebiete lassen den Holzbedarf in der ganzen Welt st?ndig wachsen. Die Holzertr?ge in den einzelnen Staaten werden gezeigt und Steigerungsm?glichkeiten angegeben. Abschlie?end werden der Ausgleich durch den zwischenstaatlichen Holzverkehr und Zukunftsaufgaben besprochen.     

Scalability of Optical Networks: Crosstalk Limitations

Optical networks represent a promising solution for the future high capacity and flexible transport network. This paper presents a model for the performance evaluation of optical networks with respect to linear crosstalk and accumulated spontaneous emission noise. The proposed model is intended for the evaluation of the crosstalk requirements on the devices needed to support an optical network with a certain number of nodes and with a given level of bit-error rate.     

Mild Stereoselective Intermolecular Acetoxylation and Azidation of α‐C−H Bonds in Tröger's Bases

Introduction of oxygen and nitrogen into organic molecules is one of the fundamental strategies for their functionalization. Traditional approaches rely on the formation of an activated intermediate, which is then modified in a subsequent step. Here we report a simple direct oxidative α‐acetoxylation and azidation of α‐C−H bonds in Tröger's base analogues promoted by N‐bromosuccinimide (NBS) and palladium(II)acetate [Pd(OAc)₂] under mild conditions. This approach is pivotal on NBS oxidizing the carbon atoms next to the nitrogen atoms in the presence of Pd(OAc)₂ followed by a reaction with oxygen‐ or nitrogen‐centred nucleophiles such as KOAc or NaN₃ to yield either the mono‐ and bisacetoxylated or azidated Tröger's base derivatives in a stereo‐ and chemoselective manner. The obtained products can be efficiently modified to access synthetically meaningful structures.

     

Potential of the renewable energy development in Jammu and Kashmir,India

The future economic growth for India is likely to result in rapid and accelerated surge in energy demand, with expected shortages in terms of supply. Many of its current policies and strategies are aimed at the improvement and possible maximization of energy production from the renewable sector. It is also clear that while energy conservation and energy efficiency can make an important contribution, renewable energies will be essential to the solution and are likely to play an increasingly important role for providing enhanced energy access, reducing consumption of fossil fuels, and helping India pursue its low-carbon progressive pathway. However, most of the states in India, like the northernmost state of Jammu and Kashmir, have experienced an energy crisis over a sustained period of time and the government both at center and state level has to embark upon with these pressing issues in a more sustainable manner and accordingly initiate various renewable energy projects within these states. This paper will provide a broad-spectrum view about the energy situation within Jammu and Kashmir and will highlight the current policies along with future strategies for the optimal utilization of renewable energy resources.     

On the distribution and performance implications of filteredinterferometric crosstalk in optical WDM networks

The distribution and performance implications of filtered interferometric crosstalk in optical networks is theoretically and experimentally studied. The probability density function is estimated by using a maximum entropy approach based on analytically derived statistical moments. The theoretical results are confirmed by relevant experimental data obtained from an amplitude shift keying direct detection (ASK/DD) system using directly, and externally modulated light sources. Power penalties are measured for both types of source modulation. The experimental results are in good agreement with theory