942 resultados para Transformations.
Resumo:
This thesis is devoted to the study of linear relationships in symmetric block ciphers. A block cipher is designed so that the ciphertext is produced as a nonlinear function of the plaintext and secret master key. However, linear relationships within the cipher can still exist if the texts and components of the cipher are manipulated in a number of ways, as shown in this thesis. There are four main contributions of this thesis. The first contribution is the extension of the applicability of integral attacks from word-based to bitbased block ciphers. Integral attacks exploit the linear relationship between texts at intermediate stages of encryption. This relationship can be used to recover subkey bits in a key recovery attack. In principle, integral attacks can be applied to bit-based block ciphers. However, specific tools to define the attack on these ciphers are not available. This problem is addressed in this thesis by introducing a refined set of notations to describe the attack. The bit patternbased integral attack is successfully demonstrated on reduced-round variants of the block ciphers Noekeon, Present and Serpent. The second contribution is the discovery of a very small system of equations that describe the LEX-AES stream cipher. LEX-AES is based heavily on the 128-bit-key (16-byte) Advanced Encryption Standard (AES) block cipher. In one instance, the system contains 21 equations and 17 unknown bytes. This is very close to the upper limit for an exhaustive key search, which is 16 bytes. One only needs to acquire 36 bytes of keystream to generate the equations. Therefore, the security of this cipher depends on the difficulty of solving this small system of equations. The third contribution is the proposal of an alternative method to measure diffusion in the linear transformation of Substitution-Permutation-Network (SPN) block ciphers. Currently, the branch number is widely used for this purpose. It is useful for estimating the possible success of differential and linear attacks on a particular SPN cipher. However, the measure does not give information on the number of input bits that are left unchanged by the transformation when producing the output bits. The new measure introduced in this thesis is intended to complement the current branch number technique. The measure is based on fixed points and simple linear relationships between the input and output words of the linear transformation. The measure represents the average fraction of input words to a linear diffusion transformation that are not effectively changed by the transformation. This measure is applied to the block ciphers AES, ARIA, Serpent and Present. It is shown that except for Serpent, the linear transformations used in the block ciphers examined do not behave as expected for a random linear transformation. The fourth contribution is the identification of linear paths in the nonlinear round function of the SMS4 block cipher. The SMS4 block cipher is used as a standard in the Chinese Wireless LAN Wired Authentication and Privacy Infrastructure (WAPI) and hence, the round function should exhibit a high level of nonlinearity. However, the findings in this thesis on the existence of linear relationships show that this is not the case. It is shown that in some exceptional cases, the first four rounds of SMS4 are effectively linear. In these cases, the effective number of rounds for SMS4 is reduced by four, from 32 to 28. The findings raise questions about the security provided by SMS4, and might provide clues on the existence of a flaw in the design of the cipher.
Resumo:
Nitrous oxide (N2O) is primarily produced by the microbially-mediated nitrification and denitrification processes in soils. It is influenced by a suite of climate (i.e. temperature and rainfall) and soil (physical and chemical) variables, interacting soil and plant nitrogen (N) transformations (either competing or supplying substrates) as well as land management practices. It is not surprising that N2O emissions are highly variable both spatially and temporally. Computer simulation models, which can integrate all of these variables, are required for the complex task of providing quantitative determinations of N2O emissions. Numerous simulation models have been developed to predict N2O production. Each model has its own philosophy in constructing simulation components as well as performance strengths. The models range from those that attempt to comprehensively simulate all soil processes to more empirical approaches requiring minimal input data. These N2O simulation models can be classified into three categories: laboratory, field and regional/global levels. Process-based field-scale N2O simulation models, which simulate whole agroecosystems and can be used to develop N2O mitigation measures, are the most widely used. The current challenge is how to scale up the relatively more robust field-scale model to catchment, regional and national scales. This paper reviews the development history, main construction components, strengths, limitations and applications of N2O emissions models, which have been published in the literature. The three scale levels are considered and the current knowledge gaps and challenges in modelling N2O emissions from soils are discussed.
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Many South East Asian cities have experienced substantial physical, economic and social transformations during the past several decades. The rapid pace of globalisation and economic restructuring has resulted in these cities receiving the full impact of urbanisation pressures. In an attempt to ease these pressures, cities such as Singapore, Hong Kong and Kuala Lumpur have advocated growth management approaches focussing especially on urban infrastructure sustainability. These approaches aim to achieve triple bottom line sustainability by balancing economic and social development, and environmental protection. This chapter evaluates three Asia-Pacific city cases, Singapore, Hong Kong and Kuala Lumpur, and assesses their experiences in managing their urban forms and infrastructure whilst promoting sustainable patterns of urban development.
Resumo:
Through international agreement to the United Nations Framework Convention on Climate Change and the Kyoto Protocol the global community has acknowledged that climate change is a global problem and sought to achieve reductions in global emissions, within a sufficient timeframe, to avoid dangerous anthropogenic interference with the climate system. The sheer magnitude of emissions reductions required within such an urgent timeframe presents a challenge to conventional regulatory approaches both internationally and within Australia. The phenomenon of climate change is temporally and geographically challenging and it is scientifically complex and uncertain. The purpose of this paper is to analyse the current Australian legal response to climate change and to examine the legal measures which have been proposed to promote carbon trading, energy efficiency, renewable energy, and carbon sequestration initiatives across Australia. As this paper illustrates, the current Australian approach is clearly ineffective and the law as it stands overwhelmingly inadequate to address Australia’s emissions and meet the enormity of the challenges posed by climate change. Consequently, the government should look towards a more effective legal framework to achieve rapid and urgent transformations in the selection of energy sources, energy use and sequestration initiatives across the Australian community.
Resumo:
Purpose - The purpose of this paper is to introduce a knowledge-based urban development assessment framework, which has been constructed in order to evaluate and assist in the (re)formulation of local and regional policy frameworks and applications necessary in knowledge city transformations. Design/methodology/approach - The research reported in this paper follows a methodological approach that includes a thorough review of the literature, development of an assessment framework in order to inform policy-making by accurately evaluating knowledge-based development levels of cities, and application of this framework in a comparative study - Boston, Vancouver, Melbourne and Manchester. Originality/value - The paper, with its assessment framework, demonstrates an innovative way of examining the knowledge-based development capacity of cities by scrutinising their economic, socio-cultural, enviro-urban and institutional development mechanisms and capabilities. Practical implications - The paper introduces a framework developed to assess the knowledge-based development levels of cities; presents some of the generic indicators used to evaluate knowledge-based development performance of cities; demonstrates how a city can benchmark its development level against that of other cities, and; provides insights for achieving a more sustainable and knowledge-based development.
Resumo:
The rise to prominence of citizen journalism is usually described as a paradigm shift in the relationship between news organizations and their audiences – ‘citizen’ or ‘amateur’ journalists are positioned as inherently different from, and possibly in competition with, ‘professional’ journalists. Some journalists in the industry have taken up this theme, and are at pains to distinguish their professional, supposedly objective and accountable practices from what they describe as the opinionated and partisan ‘armchair journalism’ of amateurs, while some citizen journalists, in turn, give as good at they get and describe the professionals as lackeys of their corporate masters who (willingly or unwittingly) fall prey to political and commercial spin. In fact, the very terminology we use to describe both sides creates the impression that professionals are not also citizens, and that citizen journalists are incapable of having professional skills and knowledges; in reality, of course, the lines between them are much less clear.
Resumo:
David Held is the Graham Wallace Chair in Political Science, and co-director of LSE Global Governance, at the London School of Economics. He is the author of many works, such as Cosmopolitanism: Ideals and Realities (2010); The Cosmopolitanism Reader (2010), with Garrett Brown; Globalisation/AntiGlobalisation (2007), Models of Democracy (2006), Global Covenant (2004) and Global Transformations: Politics, Economics and Culture (1999). Professor Held is also the co-founder, alongside Lord Professor Anthony Giddens, of Polity Press. Professor Held is widely known for his work concerning cosmopolitan theory, democracy, and social, political and economic global improvement. His Global Policy Journal endeavours to marry academic developments with practitioner realities, and contributes to the understanding and improvement of our governing systems.
Resumo:
Malaysian urban river corridors are facing major physical transformations in the 21st century. The effects of rapid development exacerbated by the competition between two key industry sectors, commercial base and tourism development in conjunction with urbanisation and industrialisation, have posted a high demand for the uses of these spaces. The political scenario and lack on consideration of ecological principles in its design solution have sparked stiff environmental and cultural constraint towards its landscape character as well as the ecological system. Therefore, a holistic approach towards improving the landscape design processes is extremely necessary to protect values of these places. Limited research has been carried out and further has created an urgent need to explore better ways to improve the landscape design processes of Malaysian urban river corridor developments that encompass the needs and aspirations of its multi-ethnic society without making any drastic changes to the landscape character of the rivers. This paper provides a brief introduction to address this significant gap and hence serves to contribute to the literature review.
Resumo:
Inspired by the initial World Social Forum in Porto Alegre Brazil, over the past decade over 200 local and regional social forums have been held, on five continents. This study has examined the nature of this broader social forum process, in particular as an aspect of the movement for 'another globalisation'. I discuss both the discourses for 'another world', as well as the development of an Alternative Globalisation Movement. As an action research study, the research took place within a variety of groups and networks. The thesis provides six accounts of groups and people striving and struggling for 'another world'. I provide a macro account of the invention and innovation of the World Social Forum. A grassroots film-makers collective provides a window into media. A local social forum opens up the radical diversity of actors. An activist exchange circle sheds light on strategic aspects of alternative globalisation. An educational initiative provides a window into transformations in pedagogy. And a situational account (of the G20 meeting in Melbourne in 2006) provides an overview of the variety of metanetworks that converge to voice demands for global justice and sustainability. In particular, this study has sought to shed light on how, within this process, groups and communities develop 'agency', a capacity to respond to the global challenges they / we face. And as part of this question, I have also explored how alternatives futures are developed and conceived, with a re-cognition of the importance of histories and geo-political (or 'eco-political') structures as contexts. I argue the World Social Forum Process is prefigurative, as an interactional process where many social alternatives are conceived, supported, developed and innovated into the world. And I argue this innovation process is meta-formative, where convergences of diverse actors comprise ‘social ecologies of alternatives’ which lead to opportunities for dynamic collaboration and partnership.
Resumo:
Business transformations are large-scale organizational change programs that, evidence suggests, are often unsuccessful. Our interest is in identifying the management capabilities required for the successful execution of these projects. We advance a service-oriented view of the enterprise, which suggests that different management services need to be identified and integrated in order to execute business transformation. In order to identify those management services that require integration, we conducted an exploratory empirical study of the demand for management services in US and Asia, and we show that two archetypes of management services exist in business transformation initiatives: transactional and transformational management services. We identify the relevant set of transactional and transformational services and discuss what the demand for these services implies for the execution of business transformations.
Resumo:
In recent years, with the impact of the global knowledge economy, a more comprehensive urban development approach, so called 'knowledge-based urban development', has gained significant popularity. This paper discusses the critical connections among knowledge-based urban development strategies, knowledge-intensive industries and information and communication technology infrastructures. In particular, the research focuses on investigating the application of the knowledge-based urban development concept by discussing one of the South East Asia's large scale knowledge-based urban development manifestations of Malaysia's Multimedia Super Corridor. The paper scrutinises Malaysia's experience in the development and evolution of the Multimedia Super Corridor from the angle of knowledge-based urban development policy implementation, infrastructural implications, and actors involved in its development and management. This paper provides a number of lessons learned from the Multimedia Super Corridor on the orchestration of knowledge-based development that is a necessity for cities seeking successful knowledge city and knowledge economy transformations.
Resumo:
Optimum Wellness involves the development, refinement and practice of lifestyle choices which resonate with personally meaningful frames of reference. Personal transformations are the means by which our frames of reference are refined across the lifespan. It is through critical reflection, supportive relationships and meaning making of our experiences that we construct and reconstruct our life paths. When individuals are able to be what they are destined to be or reach their higher purpose, then they are able to contribute to the world in positive and meaningful ways. Transformative education facilitates the changes in perspective that enable one to contemplate and travel a path in life that leads to self-actualisation. This thesis argues for an integrated theoretical framework for optimum Wellness Education. It establishes a learner centred approach to Wellness education in the form of an integrated instructional design framework derived from both Wellness and Transformative education constructs. Students’ approaches to learning and their study strategies in a Wellness education context serve to highlight convergences in the manner in which students can experience perspective transformation. As they learn to critically reflect, pursue relationships and adapt their frames of reference to sustain their pursuit of both learning and Wellness goals, strengthening the nexus between instrumental and transformative learning is a strategically important goal for educators. The aim of this exploratory research study was to examine those facets that serve to optimise the learning experiences of students in a Wellness course. This was accomplished through three research issues: 1) What are the relationships between Wellness, approaches to learning and academic success? 2) How are students approaching learning in an undergraduate Wellness subject? Why are students approaching their learning in the ways they do? 3) What sorts of transformations are students experiencing in their Wellness? How can transformative education be formulated in the context of an undergraduate Wellness subject? Subsequent to a thorough review of the literature pertaining to Wellness education, a mixed method embedded case study design was formulated to explore the research issues. This thesis examines the interrelationships between student, content and context in a one semester university undergraduate unit (a coherent set of learning activities which is assigned a unit code and a credit point value). The experiences of a cohort of 285 undergraduate students in a Wellness course formed the unit of study and seven individual students from a total of sixteen volunteers whose profiles could be constructed from complete data sets were selected for analysis as embedded cases. The introductory level course required participants to engage in a personal project involving a behaviour modification plan for a self-selected, single dimension of Wellness. Students were given access to the Standard Edition Testwell Survey to assess and report their Wellness as a part of their personal projects. To identify relationships among the constructs of Self-Regulated Learning (SRL), Wellness and Student Approaches to Learning (SAL) a blend of quantitative and qualitative methods to collect and analyse data was formulated. Surveys were the primary instruments for acquiring quantitative data. Sources included the Wellness data from Testwell surveys, SAL data from R-SPQ surveys, SRL data from MSLQ surveys and student self-evaluation data from an end of semester survey. Students’ final grades and GPA scores were used as indicators of academic performance. The sources of qualitative data included subject documentation, structured interview transcripts and open-ended responses to survey items. Subsequent to a pilot study in which survey reliability and validity were tested in context, amendments to processes for and instruments of data collection were made. Students who adopted meaning oriented (deep/achieving) approaches tended to assess their Wellness at a higher level, seek effective learning strategies and perform better in formal study. Posttest data in the main study revealed that there were significant positive statistical relationships between academic performance and total wellness scores (rs=.297, n=205, p<.01). Deep (rs=.343, n=137, p<.01) and achieving (rs=.286, n=123, p<.01) approaches to learning also significantly correlated with Wellness whilst surface approaches had negative correlations that were not significant. SRL strategies including metacognitive selfregulation, effort, help-seeking and critical thinking were increasingly correlated with Wellness. Qualitative findings suggest that while all students adopt similar patterns of day to day activities for example attending classes, taking notes, working on assignments the level of care with which these activities is undertaken varies considerably. The dominant motivational trigger for students in this cohort was the personal relevance and associated benefits of the material being learned and practiced. Students were inclined to set goals that had a positive impact on affect and used “sense of happiness” to evaluate their achievement status. Students who had a higher drive to succeed and/or understand tended to have or seek a wider range of strategies. Their goal orientations were generally learning rather than performance based and barriers presented a challenge which could be overcome as opposed to a blockage which prevented progress. Findings from an empirical analysis of the Testwell data suggest that a single third order Wellness construct exists. A revision of the instrument is necessary in order to juxtapose it with the chosen six dimensional Wellness model that forms the foundation construct in the course. Further, redevelopment should be sensitive to the Australian context and culture including choice of language, examples and scenarios used in item construction. This study concludes with an heuristic for use in Wellness education. Guided by principles of Transformative education theory and behaviour change theory, and informed by this representative case study the “CARING” heuristic is proposed as an instructional design tool for Wellness educators seeking to foster transformative learning. Based upon this study, recommendations were made for university educators to provide authentic and personal experiences in Wellness curricula. Emphasis must focus on involving students and teachers in a partnership for implementing Wellness programs both in the curriculum and co-curricularly. The implications of this research for practice are predicated on the willingness of academics to embrace transformative learning at a personal level and a professional one. To explore students’ profiles in detail is not practical however teaching students how to guide us in supporting them through the “pain” of learning is a skill which would benefit them and optimise the learning and teaching process. At a theoretical level, this research contributes to an ecological theory of Wellness education as transformational change. By signposting the wider contexts in which learning takes place, it seeks to encourage changing paradigms to ones which harness the energy of each successive contextual layer in which students live. Future research which amplifies the qualities of individuals and groups who are “Well” and seeks the refinement and development of instruments to measure Wellness constructs would be desirable for both theoretical and applied knowledge bases. Mixed method Wellness research derived and conducted by teams that incorporate expertise from multiple disciplines such as psychology, anthropology, education, and medicine would enable creative and multi-perspective programs of investigation to be designed and implemented. Congruences and inconsistencies in health promotion and education would provide valuable material for strengthening the nexus between transformational learning and behaviour change theories. Future development of and research on the effectiveness of the CARING heuristic would be valuable in advancing the understanding of pedagogies which advance rather than impede learning as a transformative process. Exploring pedagogical models that marry with transformative education may render solutions to the vexing challenge of teaching and learning in diverse contexts.
A simplified invariant line analysis for face-centred cubic/body-centred cubic precipitation systems
Resumo:
Newspapers and, if to a lesser extent as yet, linear broadcast news providers on TV and radio are in the process of being replaced as the dominant carrier media of journalism by an emerging network of online outlets.