Using real options to select stable Middleware-induced software architectures

The requirements that force decisions towards building distributed system architectures are usually of a non-functional nature. Scalability, openness, heterogeneity, and fault-tolerance are examples of such non-functional requirements. The current trend is to build distributed systems with middleware, which provide the application developer with primitives for managing the complexity of distribution, system resources, and for realising many of the non-functional requirements. As non-functional requirements evolve, the `coupling' between the middleware and architecture becomes the focal point for understanding the stability of the distributed software system architecture in the face of change. It is hypothesised that the choice of a stable distributed software architecture depends on the choice of the underlying middleware and its flexibility in responding to future changes in non-functional requirements. Drawing on a case study that adequately represents a medium-size component-based distributed architecture, it is reported how a likely future change in scalability could impact the architectural structure of two versions, each induced with a distinct middleware: one with CORBA and the other with J2EE. An option-based model is derived to value the flexibility of the induced-architectures and to guide the selection. The hypothesis is verified to be true for the given change. The paper concludes with some observations that could stimulate future research in the area of relating requirements to software architectures

Requirements to Testing of Power System Services Provided by DER Units

The present report forms the Project Deliverable ‘D 2.2’ of the DERlab NoE project, supported by the EC under Contract No. SES6-CT-518299 NoE DERlab. The present document discuss the power system services that may be provided from DER units and the related methods to test the services actually provided, both at component level and at system level

Smart Grid Technologies in Europe: An Overview

The old electricity network infrastructure has proven to be inadequate, with respect to modern challenges such as alternative energy sources, electricity demand and energy saving policies. Moreover, Information and Communication Technologies (ICT) seem to have reached an adequate level of reliability and flexibility in order to support a new concept of electricity network—the smart grid. In this work, we will analyse the state-of-the-art of smart grids, in their technical, management, security, and optimization aspects. We will also provide a brief overview of the regulatory aspects involved in the development of a smart grid, mainly from the viewpoint of the European Unio

Living City, A Collaborative Browser-Based Massively Multiplayer Online Game

This work presents the design and implementation of our Browser-based Massively Multiplayer Online Game, Living City, a simulation game fully developed at the University of Messina. Living City is a persistent and real-time digital world, running in the Web browser environment and accessible from users without any client-side installation. Today Massively Multiplayer Online Games attract the attention of Computer Scientists both for their architectural peculiarity and the close interconnection with the social network phenomenon. We will cover these two aspects paying particular attention to some aspects of the project: game balancing (e.g. algorithms behind time and money balancing); business logic (e.g., handling concurrency, cheating avoidance and availability) and, finally, social and psychological aspects involved in the collaboration of players, analyzing their activities and interconnections

Is it time to rethink project success?

The notion of success and failure in software projects are confusing. Failure is often considered in the context of the iron triangle as the inability to meet time, cost and performance constraints. Yet, while there is a consensus around the prevalence of project failure, new projects seem destined to repeat past mistakes. This paper tries to advance the discussion by offering a new perspective for reasoning about the meaning of success and the different types of software project failures. The paper advocates rising beyond the fixation with internal parameters of efficiency. It begins by discussing the limited insights from existing project failure surveys, before offering a four level model addressing the essence of successful delivery and operation in software projects and considering the different measures required in order to utilise richer measurements of success

Observing the observers – uncovering the role of values in research assessments of organic food systems

Assessing the overall effects of organic food systems is important, but also a challenge because organic food systems cannot be fully assessed from one single research perspective. The aim of the article is to uncover the role of values in assessments of organic food systems as a basis for discussing the implications of combining multiple perspectives in overall sustainability assessments of the food system. We explore how values are embedded in five research perspectives assessing organic food systems, 1) Food Science, 2) Discourse Analysis, 3) Phenomenology, 4) Neoclassical Welfare Economics and 5) Actor-Network Theory. The article shows that value has various meanings in different scientific perspectives, and that a strategy for including and balancing different forms of knowledge in overall assessments of the effects of food systems is needed. Based on the analysis, we propose five ecommendations: 1) Elucidate values as a necessary foundation for research assessment across perspectives. 2 The choice of perspective is decisive and should be openly discussed 3) Formulate common goals which can be translated into the different perspectives and 4) Consider assessment of food system sustainability a learning process and design it as such

An ESPC algorithm based approach to solve inventory deployment problem

Global competitiveness has enforced the hefty industries to become more customized. To compete in the market they are targeting the customers who want exotic products, and faster and reliable deliveries. Industries are exploring the option of satisfying a portion of their demand by converting strategically placed products, this helps in increasing the variability of product produced by them in short lead time. In this paper, authors have proposed a new hybrid evolutionary algorithm named Endosymbiotic-Psychoclonal (ESPC) algorithm to determine the amount and type of product to stock as a semi product in inventory. In the proposed work the ability of previously proposed Psychoclonal algorithm to exploit the search space has been increased by making antibodies and antigen more cooperative interacting species. The efficacy of the proposed algorithm has been tested on randomly generated datasets and the results obtained, are compared with other evolutionary algorithms such as Genetic Algorithm (GA) and Simulated Annealing (SA). The comparison of ESPC with GA and SA proves the superiority of the proposed algorithm both in terms of quality of the solution obtained, and convergence time required to reach the optimal /near optimal value of the solution

Configurations Driving NPD Performance Fit with Market Demands and Time Constraints

The research reported in this paper is aimed at developing knowledge on organizing NPD systems to optimize their contribution to performance. To this end, a systems approach to fit is used to explain the context-structure-performance relationships for NPD performance, specifically in terms of fit with market demands of the product concept and fit with time constraints of the development process. From a sample of 164 US firms, the top 15 % performers in terms of both fit with market demands and fit with time constraints have been identified. An optimized ‘Ideal Profile’ for the organization of NPD systems, formed by a consistent pattern of: NPD Process, NPD Project Structure and Management, Innovation Climate, and NPD Goal Setting and Portfolio Management, followed from the analysis of the NPD configuration of these top performers. For the calibration sample (the other 85%) significant deviation from the ideal profile on all elements of the configuration was found, the correlations between NPD Performance Fit with Market Demands and Fit with Time Constraints and total Euclidean distance are also significant. Overall, these results provide evidence for the proposition that (1) new product success is a function of a set of NPD development system decisions and (2) to truly understand the impact of those decisions, they must be considered as a holistic system.\ud The contribution of this research is in the empirical validation of the internal consistency of an ideal organizational profile for NPD systems achieving both a high NPD performance in terms of market acceptance of their new products as well in terms of the satisfactory level of the development times of those products. By also examining ideal profiles for each of these NPD performance dimensions separately, the conflicting demands created by multiple performance metrics are highlighted as well as the organizational trade-offs necessary for optimal performance. In terms of managerial implications, this also gives direction for organizational redesign to firms either wanting to maximize their product concept (Fit with Market Demands) or development process (Fit with Time Constraints) performance

Smart grid architecture for rural distribution networks: application to a Spanish pilot network

This paper presents a novel architecture for rural distribution grids. This architecture is designed to modernize traditional rural networks into new Smart Grid ones. The architecture tackles innovation actions on both the power plane and the management plane of the system. In the power plane, the architecture focuses on exploiting the synergies between telecommunications and innovative technologies based on power electronics managing low scale electrical storage. In the management plane, a decentralized management system is proposed based on the addition of two new agents assisting the typical Supervisory Control And Data Acquisition (SCADA) system of distribution system operators. Altogether, the proposed architecture enables operators to use more effectively—in an automated and decentralized way—weak rural distribution systems, increasing the capability to integrate new distributed energy resources. This architecture is being implemented in a real Pilot Network located in Spain, in the frame of the European Smart Rural Grid project. The paper also includes a study case showing one of the potentialities of one of the principal technologies developed in the project and underpinning the realization of the new architecture: the so-called Intelligent Distribution Power Router.Postprint (published version

Wind generator behaviour in a pay-as-bid curtailment market

A pay-as-bid curtailment market, where Wind Power Plants (WPPs) may offer prices to have their output reduced in the event of network balancing or stability constraints, is one approach towards the market integration of a high proportion of wind energy onto a power system. Such a market aims to procure curtailment at a cost close to the marginal value of the electricity plus renewable subsidies and incentives, reducing risks for WPPs while minimising costs to the Independent System Operator (ISO). Through the use of game theory and market modelling, a key set of bidding strategies are identified that may evolve within such a market, which may act in opposition to the goals of the ISO. These are applied to a variety of network conditions in order to determine their likely impact and the resulting bidding signals provided to market participants. Bidding behaviours and market fluidity may also be affected by factors particular to wind power plants. Through analysis of both ex ante and ex post case studies, the existence of these behaviours is demonstrated, illustrating that a pay-as-bid curtailment market may not be efficient at price discovery in practice