14 resultados para Key feature
em Aston University Research Archive
Resumo:
The concept of communities of practice (CoPs) has rapidly gained ground in fields such as knowledge management and organisational learning since it was first identified by Lave and Wenger (1991) and Brown and Duguid (1991). In this article, we consider a related concept that we have entitled “communities of implementation.” Communities of implementation (CoIs) are similar to communities of practice in that they offer an opportunity for a collection of individuals to support each other and share knowledge in a dynamic environment and on a topic in which they share interest. In addition, and to differentiate them from CoPs, a community of implementation extends the responsibilities of a CoP by having as its focus the implementation of a programme of change. This may well extend to designing the change programme. Thus, whereas a main purpose of a CoP is to satisfy “a real need to know what each other knows” (Skyrme, 1999) in an informal way, we argue that a main purpose of a community of implementation is to “pool individual knowledge (including contacts and ways of getting things done) to stimulate collective enthusiasm in order to take more informed purposeful action for which the members are responsible.” Individual and collective responsibility and accountability for successfully implementing the actions/change programme is a key feature of a community of implementation. Without these pressures the members might lower the priority of implementation, allowing competing priorities to dominate their attention and resources. Without responsibility and accountability, the result is likely to be (at best) an organisation which has not begun a change programme, or (at worst) an organisation which is stuck halfway through another failing initiative. To achieve these additional objectives beyond those of a CoP, the CoI needs to provide heightened support to its members. In fact often the members will collectively strategise the development and implementation of the change programme they are leading in the organisation. Other concepts similar to CoPs have appeared in the literature, for example “communities of knowing” (Boland & Tenkasi, 1995), but none have a specific focus on implementation. Perhaps the closest example of a CoI, as suggested by our definition, is reported by Karsten, Lyytinen, Hurskainen, and Koskelainen (2001) who describe a CoP in a paper machinery manufacturer which seems to have the necessary focus on implementation. The theoretical aspects of this article will explore the relationship between CoPs and CoIs, and the needs for different arrangements for a CoI. The practical aspect of this article will consist of a report on a case study of a CoI that was successful in its implementation of a programme of change that aimed to improve its organisation’s knowledge management activities. Over two years the CoI implemented a suite of complementary actions across the organisation. These actions transformed the organisation and moved it towards achieving its ‘core values’ and overall objectives. The article will explore: the activities that formed and gelled the community, the role of the community in the implementation of actions, and experiences from key members of this community on its success and potential improvements.
Resumo:
Purpose: The purpose of this paper is to investigate the use of 802.11e MAC to resolve the transmission control protocol (TCP) unfairness. Design/methodology/approach: The paper shows how a TCP sender may adapt its transmission rate using the number of hops and the standard deviation of recently measured round-trip times to address the TCP unfairness. Findings: Simulation results show that the proposed techniques provide even throughput by providing TCP fairness as the number of hops increases over a wireless mesh network (WMN). Research limitations/implications: Future work will examine the performance of TCP over routing protocols, which use different routing metrics. Other future work is scalability over WMNs. Since scalability is a problem with communication in multi-hop, carrier sense multiple access (CSMA) will be compared with time division multiple access (TDMA) and a hybrid of TDMA and code division multiple access (CDMA) will be designed that works with TCP and other traffic. Finally, to further improve network performance and also increase network capacity of TCP for WMNs, the usage of multiple channels instead of only a single fixed channel will be exploited. Practical implications: By allowing the tuning of the 802.11e MAC parameters that have previously been constant in 802.11 MAC, the paper proposes the usage of 802.11e MAC on a per class basis by collecting the TCP ACK into a single class and a novel congestion control method for TCP over a WMN. The key feature of the proposed TCP algorithm is the detection of congestion by measuring the fluctuation of RTT of the TCP ACK samples via the standard deviation, plus the combined the 802.11e AIFS and CWmin allowing the TCP ACK to be prioritised which allows the TCP ACKs will match the volume of the TCP data packets. While 802.11e MAC provides flexibility and flow/congestion control mechanism, the challenge is to take advantage of these features in 802.11e MAC. Originality/value: With 802.11 MAC not having flexibility and flow/congestion control mechanisms implemented with TCP, these contribute to TCP unfairness with competing flows. © Emerald Group Publishing Limited.
Resumo:
The attention of linguists has increasingly shifted from grammar to lexis. Collocation has emerged as a key feature of lexis. Research using large language corpora has not only helped to identify the significant collocates of individual words but also to confirm the importance of collocation in the language system. John Sinclair has suggested that language operates on two principles: open choice and idiom. If so, then collocation would appear to be the minimal level of idiomaticity. One problem with collocation is that words that habitually co-occur form less distinct, often discontinuous, idiomatic units, whereas grammar generally works with more precisely delineated and contiguous structural units. This paper uses examples from corpus evidence to look at various aspects of collocation.
Resumo:
The aim of this thesis is to examine the experience of time of four professional occupational groups working in public sector organisations and the factors affecting this experience. The literature on time and work is examined to delineate the key parameters of research in this area. A broad organisation behaviour approach to the experience of time and work is developed in which individual, occupational, organisational and socio-political factors are inter-related. The experience of secondary school teachers, further education lecturers, general medical practitioners and hosoital consultants is then examined. Multiple methods of data collection are used: open-ended interviews, a questionnaire survey and the analysis of key documents relating to the institutional settings in which the four groups work. The research aims to develop our knowledge of working time by considering the dimensions of the experience of time at work, the contexts in wlhich this experience is generated and the constraints these contexts give rIse to. By developing our understanding of time as a key feature of work experience we also extend our knowledge of organisation behaviour in general. In conclusion a model of the factors relating the experience of time to the negotiation of time at work is presented.
Resumo:
Background Pharmacy has experienced both incomplete professionalization and deprofessionalization. Since the late 1970s, a concerted attempt has been made to re-professionalize pharmacy in the United Kingdom (UK) through role extension—a key feature of which has been a drive for greater pharmacy involvement in public health. However, the continual corporatization of the UK community pharmacy sector may reduce the professional autonomy of pharmacists and may threaten to constrain attempts at reprofessionalization. Objectives The objectives of the research: to examine the public health activities of community pharmacists in the UK; to explore the attitudes of community pharmacists toward recent relevant UK policy and barriers to the development of their public health function; and, to investigate associations between activity, attitudes, and the type of community pharmacy worked in (eg, supermarket, chain, independent). Methods A self-completion postal questionnaire was sent to a random sample of practicing community pharmacists, stratified for country and sex, within Great Britain (n = 1998), with a follow-up to nonresponders 4 weeks later. Data were analyzed using SPSS (SPSS Inc., Chicago, IL, USA) (v12.0). A final response rate of 51% (n = 1023/1998) was achieved. Results The level of provision of emergency hormonal contraception on a patient group direction, supervised administration of medicines, and needle-exchange schemes was lower in supermarket pharmacies than in the other types of pharmacy. Respondents believed that supermarkets and the major multiple pharmacy chains held an advantageous position in terms of attracting financing for service development despite suggesting that the premises of such pharmacies may not be the most suitable for the provision of such services. Conclusions A mixed market in community pharmacy may be required to maintain a comprehensive range of pharmacy-based public health services and provide maximum benefit to all patients. Longitudinal monitoring is recommended to ensure that service provision is adequate across the pharmacy network.
Resumo:
Working within the framework of the branch of Linguistics known as discourse analysis, and more specifically within the current approach of genre analysis, this thesis presents an analysis of the English of economic forecasting. The language of economic forecasting is highly specialised and follows certain conventions of structure and style. This research project identifies these characteristics and explains them in terms of their communicative function. The work is based on a corpus of texts published in economic reports and surveys by major corporate bodies. These documents are targeted at an international expert readership familiar with this genre. The data is analysed at two broad levels: firstly, the macro-level of text structure which is described in terms of schema-theory, a currently influential model of analysis, and, secondly, the micro-level of authors' strategies for modulating the predictions which form the key move in the forecasting schema. The thesis aims to contribute to the newly developing field of genre analysis in a number of ways: firstly, by a coverage of a hitherto neglected but intrinsically interesting and important genre (Economic Forecasting); secondly, by testing the applicability of existing models of analysis at the level of schematic structure and proposing a genre-specific model; thirdly by offering insights into the nature of modulation of propositions which is often broadly classified as `hedging' or `modality', and which has been recently described as lq`an area for prolonged fieldwork'. This phenomenon is shown to be a key feature of this particular genre. It is suggested that this thesis, in addition to its contribution to the theory of genre analysis, provides a useful basis for work by teachers of English for Economics, an important area of English for Specific Purposes.
Resumo:
A key feature of ‘TESOL Quarterly’, a leading journal in the world of TESOL/applied linguistics, is its ‘Forum’ section which invites ‘responses and rebuttals’ from readers to any of its articles. These ‘responses or rebuttals’ form the focus of this research. In the interchanges between readers reacting to earlier research articles in TESOL Quarterly and authors responding to the said reaction I – examine the texts for evidence of genre-driven structure, whether shared between both ‘reaction’ and ‘response’ sections, or peculiar to each section, and attempt to determine the precise nature of the intended communicative purpose in particular and the implications for academic debate in general. The intended contribution of this thesis is to provide an analysis of how authors of research articles and their critics pursue their efforts beyond the research article which precipitated these exchanges in order to be recognized by their discourse community as, in the terminology of Swales (1981:51), ‘Primary Knowers’. Awareness of any principled generic process identified in this thesis may be of significance to practitioners in the applied linguistics community in their quest to establish academic reputation and in their pursuit of professional development. These findings may also be of use in triggering productive community discussion as a result of the questions they raise concerning the present nature of academic debate. Looking beyond the construction and status of the texts themselves, I inquire into the kind of ideational and social organization such exchanges keep in place and examine an alternative view of interaction. This study breaks new ground in two major ways. To the best of my knowledge, it is the first exploration of a bipartite, intertextual structure laying claim to genre status. Secondly, in its recourse to the comments of the writers’ themselves rather than relying exclusively on the evidence of their texts, as is the case with most studies of genre, this thesis offers an expanded opportunity to discuss perhaps the most interesting aspects of genre analysis – the light it throws on social ends and the role of genre in determining the nature of current academic debate as it here emerges.
Resumo:
Over the last three decades foreign direct investment (FDI) has become the most visible driver of globalisation. It has grown faster than world output and international trade and now reports world annual flows exceeding 1,000 billion US dollars. In this period, Germany has undergone significant changes in order to play an important role in the globalisation process. Apart from being a member state of the European Union (EU) whose key feature is the free flow of trade, investment and labour, the re-unification of East and West Germany in 1990 has been a significant development. This in effect has meant that East Germany as well as other Eastern European nations opened up to foreign investment for the first time. In this period, Germany has attracted in excess of 10 per cent of inward FDI into the EU and invested around 15 per cent of all FDI in the EU. This thesis explores empirically the potential impact of FDI on firms operating in and investing from Germany over a ten year period. Using panel data at the firm-level it concentrates on three areas relating to FDI. Firstly, it considers whether foreign-owned firms are more productive than German multinational firms and German non-multinational firms. Secondly, the thesis considers the impact of German investments abroad on domestic productivity. Finally, employment effects emanating from outward high-tech FDI are estimated for the leading OECD (Organisation of Economic Co-operation and Development) countries, namely Germany, Belgium, France, the Netherlands, Sweden, the United Kingdom and Japan. The findings of the first analysis indicate that while foreign-owned firms are generally more productive than German non-multinationals, there is no clear cut difference between foreign-owned firms and German multinationals. These differences would not have been uncovered, had the analysis compared foreign firms with all domestic firms. Equally, location within Germany is also important, as this productivity gap is more pronounced for firms which are located in the Eastern states. The findings of the second analysis suggest that engaging in outward FDI has an overall positive effect on the parent firm's productivity at home. Finally, results of the third analysis show that an expansion of high-tech offshoring activities by OECD multinationals (MNEs) is not associated with any reduction in employment at home.
Resumo:
Wireless Mesh Networks (WMNs) have emerged as a key technology for the next generation of wireless networking. Instead of being another type of ad-hoc networking, WMNs diversify the capabilities of ad-hoc networks. Several protocols that work over WMNs include IEEE 802.11a/b/g, 802.15, 802.16 and LTE-Advanced. To bring about a high throughput under varying conditions, these protocols have to adapt their transmission rate. In this paper, we have proposed a scheme to improve channel conditions by performing rate adaptation along with multiple packet transmission using packet loss and physical layer condition. Dynamic monitoring, multiple packet transmission and adaptation to changes in channel quality by adjusting the packet transmission rates according to certain optimization criteria provided greater throughput. The key feature of the proposed method is the combination of the following two factors: 1) detection of intrinsic channel conditions by measuring the fluctuation of noise to signal ratio via the standard deviation, and 2) the detection of packet loss induced through congestion. We have shown that the use of such techniques in a WMN can significantly improve performance in terms of the packet sending rate. The effectiveness of the proposed method was demonstrated in a simulated wireless network testbed via packet-level simulation.
Resumo:
Using the integrable nonlinear Schrodinger equation (NLSE) as a channel model, we describe the application of nonlinear spectral management for effective mitigation of all nonlinear distortions induced by the fiber Kerr effect. Our approach is a modification and substantial development of the so-called eigenvalue communication idea first presented in A. Hasegawa, T. Nyu, J. Lightwave Technol. 11, 395 (1993). The key feature of the nonlinear Fourier transform (inverse scattering transform) method is that for the NLSE, any input signal can be decomposed into the so-called scattering data (nonlinear spectrum), which evolve in a trivial manner, similar to the evolution of Fourier components in linear equations. We consider here a practically important weakly nonlinear transmission regime and propose a general method of the effective encoding/modulation of the nonlinear spectrum: The machinery of our approach is based on the recursive Fourier-type integration of the input profile and, thus, can be considered for electronic or all-optical implementations. We also present a novel concept of nonlinear spectral pre-compensation, or in other terms, an effective nonlinear spectral pre-equalization. The proposed general technique is then illustrated through particular analytical results available for the transmission of a segment of the orthogonal frequency division multiplexing (OFDM) formatted pattern, and through WDM input based on Gaussian pulses. Finally, the robustness of the method against the amplifier spontaneous emission is demonstrated, and the general numerical complexity of the nonlinear spectrum usage is discussed. © 2013 Optical Society of America.
Resumo:
Wireless Mesh Networks (WMNs) have emerged as a key technology for the next generation of wireless networking. Instead of being another type of ad-hoc networking, WMNs diversify the capabilities of ad-hoc networks. Several protocols that work over WMNs include IEEE 802.11a/b/g, 802.15, 802.16 and LTE-Advanced. To bring about a high throughput under varying conditions, these protocols have to adapt their transmission rate. This paper proposes a scheme to improve channel conditions by performing rate adaptation along with multiple packet transmission using packet loss and physical layer condition. Dynamic monitoring, multiple packet transmission and adaptation to changes in channel quality by adjusting the packet transmission rates according to certain optimization criteria provided greater throughput. The key feature of the proposed method is the combination of the following two factors: 1) detection of intrinsic channel conditions by measuring the fluctuation of noise to signal ratio via the standard deviation, and 2) the detection of packet loss induced through congestion. The authors show that the use of such techniques in a WMN can significantly improve performance in terms of the packet sending rate. The effectiveness of the proposed method was demonstrated in a simulated wireless network testbed via packet-level simulation.
Resumo:
This paper addresses the security of a specific class of common watermarking methods based on Dither modulation-quantisation index modulation (DM-QIM) and focusing on watermark-only attacks (WOA). The vulnerabilities of and probable attacks on lattice structure based watermark embedding methods have been presented in the literature. DM-QIM is one of the best known lattice structure based watermarking techniques. In this paper, the authors discuss a watermark-only attack scenario (the attacker has access to a single watermarked content only). In the literature it is an assumption that DM-QIM methods are secure to WOA. However, the authors show that the DM-QIM based embedding method is vulnerable against a guided key guessing attack by exploiting subtle statistical regularities in the feature space embeddings for time series and images. Using a distribution-free algorithm, this paper presents an analysis of the attack and numerical results for multiple examples of image and time series data.
Resumo:
This paper addresses the security of a specific class of common watermarking methods based on Dither modulation-quantisation index modulation (DM-QIM) and focusing on watermark-only attacks (WOA). The vulnerabilities of and probable attacks on lattice structure based watermark embedding methods have been presented in the literature. DM-QIM is one of the best known lattice structure based watermarking techniques. In this paper, the authors discuss a watermark-only attack scenario (the attacker has access to a single watermarked content only). In the literature it is an assumption that DM-QIM methods are secure to WOA. However, the authors show that the DM-QIM based embedding method is vulnerable against a guided key guessing attack by exploiting subtle statistical regularities in the feature space embeddings for time series and images. Using a distribution-free algorithm, this paper presents an analysis of the attack and numerical results for multiple examples of image and time series data.
Resumo:
Hypoxia is a prominent feature of chronically inflamed tissues. Oxygen-sensing hydroxylases control transcriptional adaptation to hypoxia through the regulation of hypoxia-inducible factor (HIF) and nuclear factor ?B (NF-?B), both of which can regulate the inflammatory response. Furthermore, pharmacologic hydroxylase inhibitors reduce inflammation in multiple animal models. However, the underlying mechanism(s) linking hydroxylase activity to inflammatory signaling remains unclear. IL-1ß, a major proinflammatory cytokine that regulates NF-?B, is associated with multiple inflammatory pathologies. We demonstrate that a combination of prolyl hydroxylase 1 and factor inhibiting HIF hydroxylase isoforms regulates IL-1ß-induced NF-?B at the level of (or downstream of) the tumor necrosis factor receptor-associated factor 6 complex. Multiple proteins of the distal IL-1ß-signaling pathway are subject to hydroxylation and form complexes with either prolyl hydroxylase 1 or factor inhibiting HIF. Thus, we hypothesize that hydroxylases regulate IL-1ß signaling and subsequent inflammatory gene expression. Furthermore, hydroxylase inhibition represents a unique approach to the inhibition of IL-1ß-dependent inflammatory signaling.