792 resultados para 1504
Resumo:
The pseudo-spectral solution method offers a flexible and fast alternative to the more usual finite element and volume methods, particularly when the long-time transient behaviour of a system is of interest. The exact solution is obtained at grid collocation points leading to superior accuracy on modest grids. Furthermore, the grid can be freely adapted in time and space to particular flow conditions or geometric variations, especially useful where strongly coupled, time-dependent, multi-physics solutions are investigated. Examples include metallurgical applications involving the interaction of electromagnetic fields and conducting liquids with a free surface. The electromagnetic field determines the instantaneous liquid volume shape, which then affects the electromagnetic field. A general methodology of the pseudo-spectral approach is presented, with several instructive example applications: the aluminium electrolysis MHD problem, induction melting in a cold crucible and the dynamics of AC/DC magnetically levitated droplets. Finally, comparisons with available analytical solutions and to experimental measurements are discussed.
Resumo:
Generally speaking, the term temporal logic refers to any system of rules and symbolism for representing and reasoning about propositions qualified in terms of time. In computer science, particularly in the domain of Artificial Intelligence, there are mainly two known approaches to the representation of temporal information: modal logic approaches including tense logic and hybrid temporal logic, and predicate logic approaches including temporal arguement method and reified temporal logic. On one hand, while tense logic, hybrid temporal logic and temporal argument method enjoy formal theoretical foundations, their expressiveness has been criticised as not power enough for representing general temporal knowledge; on the other hand, although reified temporal logic provides greater expressive power, most of the current systems following the temporal reification lack of complete and sound axiomatic theories. With there observations in mind, a new reified temporal logic with clear syntax and semantics in terms of a sound and complete axiomatic formalism is introduced in this paper, which retains all the expressive power of temporal reification.
Resumo:
Deliberating on Enterprise Resource Planning (ERP) software sourcing and provision, this paper contrasts the corporate environment with the small business environment. The paper is about Enterprise Resource Planning client (ERPc) expectations and Enterprise Resource Planning vendor (ERPv) value propositions as a mutually compatible process for achieving acceptable standards of ERP software performance. It is suggested that a less-than-equitable vendor–client relationship would not contribute to the implementation of the optimum solution. Adapting selected theoretical concepts and models, the researchers analyse ERPv to ERPc relationship. This analysis is designed to discover if the provision of the very large ERP vendors who market systems such as SAP, and the provision of the smaller ERP vendors (in this instance Eshbel Technologies Ltd who market an ERP software solution called Priority) when framed as a value proposition (Walters, D. (2002) Operations Strategy. Hampshire, UK: Palgrave), is at all comparable or distinctive.
Resumo:
This paper addresses the difficult problem of how to improve the process of evaluating organisational change. Given that the data emergent from an evaluative exercise will strongly influence the subsequent strategic and operational decisions taken by organisational managers, it is critical that the evaluation approach itself is capable of delivering high quality, accurate and timely data. The aim of this paper is to examine the role of the IT-based Optionfinder Technology used in conjunction with focus groups, in generating management decision-making data, and reflecting the changes in key performance indicators in a utility organisation. The case study research evaluates the innovative integrative approach adopted by the utility organisation and concludes that the proposed approach contributes to improvements in the decision-making capability of managers.
Resumo:
In the USA today, the precipitous rise of new financial mechanisms for capitalisation of firms as well as the merger and acquisition of others, especially risk equity capital through venture capitalist and investment banking, has sparked growth and helped to bring the economy out of the 1990s recession into a robust continuous growth pattern well positioned for the next century. The scenario is not new. For the venture capitalists of ''Silicon Valley'' in California, the experience is not new. They have seen the new industries arise before, like a phoenix from ashes of ruin, despair and even failure. Venture capital poured into high tech start-up companies has been an enormous source of financial support for the entrepreneurs who head new and growing companies. The mid-1990s marked the most dramatic increase yet recorded. Indicators, such as the NASDAQ document, outlined the solid and continuous growth in high tech industries. The paper discusses investment in US corporations within the context of governance and management of the company. Discussion about the various forms of finance are related to the organisation and management of the US corporation. Critical to any firm today are its ability to find innovative, new products or services. A growing literature on resource-base framework for analysis will be discussed as part of the firm's development of research for commercialisation. The results of a recent survey further shed light on the relationship between corporate financial management and allocated resources for research and development as the ''engine'' for new product development and therefore corporate market share and growth. The conclusion is that more financial mechanisms will be created and changed within US corporate systems to adjust, grow, and expand companies in the global economic arena, as the inevitable economic pattern leads to mergers, consolidations, and increasing cooperation and alliances among firms.
Resumo:
Transparency in nonprofit sector and foundations, as an element to enhance the confidence of stakeholders in the organization, is a fact shown by several studies in recent decades. Transparency can be considered in various fields and through different channels. In our study we focused on the analysis of the organizational and economic transparency of foundations, shown through the voluntary information on their Website. We review the theoretical previous studies published to put to the foundations within the framework of the social economy. This theoretical framework has focused on accountability that make foundations in relation to its social function and its management, especially since the most recent focus of information transparency across the Website.In this theoretical framework was made an index to quantify the voluntary information which is shown on its website. This index has been developed ad hoc for this study and applied to a group of large corporate foundations.With the application of these data are obtained two kind of results, to a descriptive level and to a inferential level.We analyzed the statistical correlation between economic transparency and organizational transparency offered in the Website through quantified variables by a multiple linear regression. This empirical analysis allows us to draw conclusions about the level of transparency offered by these organizations in relation to their organizational and financial information, as well as explain the relation between them.
Resumo:
Cooperatives have a long historical experience in the Spanish economy and have demonstrated their ability to compete against traditional firms in the market. To maintain this capability, while taking advantage of the competitive advantages associated with their idiosyncrasies as social economy enterprises, they should take into consideration that the economy is increasingly globalized and increasingly knowledge-based, especially with regards to technological content. As a consequence, the innovative capacity appears to be a key aspect in order to be able to challenge competitors. This article characterizes the innovative behavior of cooperatives in the region of Castile and Leon and analyses the internal and external factors affecting their innovative performance, based on data from a survey of 581 cooperatives. The results of the empirical analysis, which is performed by multivariate binary logistic regression on various types of innovation, lead us to identify the size of the organizations, the existence of planning, the R & D activities and the human capital as the main determining factors.
Resumo:
Software product development is recognised as difficult due to the intangible nature of the product, requirements elicitation, effective progress measurement, and so forth. In this paper, we describe some of the challenges of software product development and how the challenges are being met by lean management principles and techniques. Specifically, we examine lean principles and techniques that were devised by Toyota and other manufacturers over the last 50 years. Applying lean principles to software development projects has been advocated for over ten years and it will be shown that the extensive lean literature is a valuable source of ideas for software development. A case study with a software development organisation, Timberline Inc., will demonstrate that lean principles and techniques can be successfully applied to software product development.
Resumo:
The method described here cannot fully replace the analysis of large columns by small test columns (microcolumns). The procedure, however, is suitable for speeding up the determination of adsorption parameters of dye onto the adsorbent and for speeding up the initial screening of a large adsorbent collection that can be tedious if a several adsorbents and adsorption conditions must be tested. The performance of methylene blue (MB), a basic dye, Cibacron reactive black (RB) and Cibacron reactive yellow (RY) was predicted in this way and the influence of initial dye concentration and other adsorption conditions on the adsorption behaviour were demonstrated.