Migrating agile methods to standardized development practice

Situated process and quality frame-works offer a way to resolve the tensions that arise when introducing agile methods into standardized software development engineering. For these to be successful, however, organizations must grasp the opportunity to reintegrate software development management, theory, and practice

Reliability assessment of water distribution systems with statistical entropy and other surrogate measures

There is ever increasing commercial and regulatory pressure to minimise the cost of water distribution networks even as the demand for them keeps on growing. But cost minimizing is only one of the demands placed on network design. Satisfactory networks are required to operate above a minimum level even if they experience failure of components. Reliable hydraulic performance can be achieved if sufficient redundancy is built in the network. This has given rise to various water distribution system optimization methods including genetic algorithms and other evolutionary computing methods. Evolutionary computing approaches frequently assess the suitability of enormous numbers of potential solutions for which the calculation of accurate reliability measures could be computationally prohibitive. Therefore, surrogate reliability measures are frequently used to ease the computational burden. The aim of this paper is to assess the correlation of surrogate reliability measures in relation to more accurate measures. The surrogate measures studied are statistical entropy, network resilience, resilience index and modified resilience index. The networks were simulated with the prototype software PRAAWDS that produces more realistic results for pressure-deficient water distribution systems. Statistical entropy outperformed resilience index in this study. The results also demonstrate there is a strong correlation between entropy and failure tolerance

Performance of CSMA in Multi-Channel Wireless Networks

We analyze the performance of CSMA in multi-channel wireless networks, accounting for the random nature of traffic. Specifically, we assess the ability of CSMA to fully utilize the radio resources and in turn to stabilize the network in a dynamic setting with flow arrivals and departures. We prove that CSMA is optimal in ad-hoc mode but not in infrastructure mode, when all data flows originate from or are destined to some access points, due to the inherent bias of CSMA against downlink traffic. We propose a slight modification of CSMA, that we refer to as flow-aware CSMA, which corrects this bias and makes the algorithm optimal in all cases. The analysis is based on some time-scale separation assumption which is proved valid in the limit of large flow sizes

Instruction sequence processing operators

Instruction sequence is a key concept in practice, but it has as yet not come prominently into the picture in theoretical circles. This paper concerns instruction sequences, the behaviours produced by them under execution, the interaction between these behaviours and components of the execution environment, and two issues relating to computability theory. Positioning Turing's result regarding the undecidability of the halting problem as a result about programs rather than machines, and taking instruction sequences as programs, we analyse the autosolvability requirement that a program of a certain kind must solve the halting problem for all programs of that kind. We present novel results concerning this autosolvability requirement. The analysis is streamlined by using the notion of a functional unit, which is an abstract state-based model of a machine. In the case where the behaviours exhibited by a component of an execution environment can be viewed as the behaviours of a machine in its different states, the behaviours concerned are completely determined by a functional unit. The above-mentioned analysis involves functional units whose possible states represent the possible contents of the tapes of Turing machines with a particular tape alphabet. We also investigate functional units whose possible states are the natural numbers. This investigation yields a novel computability result, viz. the existence of a universal computable functional unit for natural numbers.Comment: 37 pages; missing equations in table 3 added; combined with arXiv:0911.1851 [cs.PL] and arXiv:0911.5018 [cs.LO]; introduction and concluding remarks rewritten; remarks and examples added; minor error in proof of theorem 4 correcte

The liberty of the post-moderns? Market and civic freedom within the EU

Taking its cue from Benjamin's Constant's famous essay, this article uses the case of EU citizenship to explore how far ancient, civic, freedom can be combined with modern, market, freedom. Many commentators have, in different ways, argued that the forces promoting European integration call for a new form of post-national citizenship that either builds civic freedom on the basis of the liberties of the moderns or does away with the need for it altogether. These arguments are disputed. Constant perceptively raised a number of problems with this analysis, while ignoring - or being ignorant of - a number of others. As he noted, ancient liberty corrects various pathologies and lacunas of modern liberty, but he overlooked the degree to which its survival rested on the continuing importance of certain pre-modern forms of social solidarity in modern times. Those seeking new forms of post-modern citizenship tend to ignore one or other or both these points. The piece concludes by arguing that the only practical way of combining ancient and modern liberty within the EU is to view it as a particularly intense form of international cooperation between democratic states rather than as a supranational organisation that transcends its component parts

Modern Concepts of Financial and Non-Financial Motivation of Service Industries Staff

In modern conditions the questions of personnel management, including motivation, acquire new meaning. Particularly given the problems relevant to the service sector, where at the beginning of the XXI century employing more than 60% of the workforce in developed countries. These circumstances determine the need for a modern concept of material and immaterial motivation of service industries. Such factors determine the need for the development modern concept of material and immaterial motivation of service industries staff. To obtain indicated objective during research analyzed the existing concepts and paradigm of staff motivation with highlighting their advantages and disadvantages. The results obtained allowed to establish that scientific and expert community does not have the unified approach to the classification and identification of the most effective ones. Special attention is given to modern developments and approaches to the motivation problem. This fact caused the structure of follow studies, including three interlinked vectors: analysis of the essential content of the fundamental concepts in the field of staff motivation; defining features of employee motivation at the enterprises sphere of services; introduction to the key successful international practices which apply by service companies. In general, the results obtained enabled the author’s model of the modern concept of material and non-material motivation at the enterprises the service sector and the corresponding mechanism for the implementation

The use of data-mining for the automatic formation of tactics

This paper discusses the usse of data-mining for the automatic formation of tactics. It was presented at the Workshop on Computer-Supported Mathematical Theory Development held at IJCAR in 2004. The aim of this project is to evaluate the applicability of data-mining techniques to the automatic formation of tactics from large corpuses of proofs. We data-mine information from large proof corpuses to find commonly occurring patterns. These patterns are then evolved into tactics using genetic programming techniques