984 resultados para Quintus, Smyrnaeus, 4th cent.


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Animal models of refractive error development have demonstrated that visual experience influences ocular growth. In a variety of species, axial anisometropia (i.e. a difference in the length of the two eyes) can be induced through unilateral occlusion, image degradation or optical manipulation. In humans, anisometropia may occur in isolation or in association with amblyopia, strabismus or unilateral pathology. Non-amblyopic myopic anisometropia represents an interesting anomaly of ocular growth, since the two eyes within one visual system have grown to different endpoints. These experiments have investigated a range of biometric, optical and mechanical properties of anisometropic eyes (with and without amblyopia) with the aim of improving our current understanding of asymmetric refractive error development. In the first experiment, the interocular symmetry in 34 non-amblyopic myopic anisometropes (31 Asian, 3 Caucasian) was examined during relaxed accommodation. A high degree of symmetry was observed between the fellow eyes for a range of optical, biometric and biomechanical measurements. When the magnitude of anisometropia exceeded 1.75 D, the more myopic eye was almost always the sighting dominant eye. Further analysis of the optical and biometric properties of the dominant and non-dominant eyes was conducted to determine any related factors but no significant interocular differences were observed with respect to best-corrected visual acuity, corneal or total ocular aberrations during relaxed accommodation. Given the high degree of symmetry observed between the fellow eyes during distance viewing in the first experiment and the strong association previously reported between near work and myopia development, the aim of the second experiment was to investigate the symmetry between the fellow eyes of the same 34 myopic anisometropes following a period of near work. Symmetrical changes in corneal and total ocular aberrations were observed following a short reading task (10 minutes, 2.5 D accommodation demand) which was attributed to the high degree of interocular symmetry for measures of anterior eye morphology, and corneal biomechanics. These changes were related to eyelid shape and position during downward gaze, but gave no clear indication of factors associated with near work that might cause asymmetric eye growth within an individual. Since the influence of near work on eye growth is likely to be most obvious during, rather than following near tasks, in the third experiment the interocular symmetry of the optical and biometric changes was examined during accommodation for 11 myopic anisometropes. The changes in anterior eye biometrics associated with accommodation were again similar between the eyes, resulting in symmetrical changes in the optical characteristics. However, the more myopic eyes exhibited slightly greater amounts of axial elongation during accommodation which may be related to the force exerted by the ciliary muscle. This small asymmetry in axial elongation we observed between the eyes may be due to interocular differences in posterior eye structure, given that the accommodative response was equal between eyes. Using ocular coherence tomography a reduced average choroidal thickness was observed in the more myopic eyes compared to the less myopic eyes of these subjects. The interocular difference in choroidal thickness was correlated with the magnitude of spherical equivalent and axial anisometropia. The symmetry in optics and biometrics between fellow eyes which have undergone significantly different visual development (i.e. anisometropic subjects with amblyopia) is also of interest with respect to refractive error development. In the final experiment the influence of altered visual experience upon corneal and ocular higher-order aberrations was investigated in 21 amblyopic subjects (8 refractive, 11 strabismic and 2 form deprivation). Significant differences in aberrations were observed between the fellow eyes, which varied according to the type of amblyopia. Refractive amblyopes displayed significantly higher levels of 4th order corneal aberrations (spherical aberration and secondary astigmatism) in the amblyopic eye compared to the fellow non-amblyopic eye. Strabismic amblyopes exhibited significantly higher levels of trefoil, a third order aberration, in the amblyopic eye for both corneal and total ocular aberrations. The results of this experiment suggest that asymmetric visual experience during development is associated with asymmetries in higher-order aberrations, proportional to the magnitude of anisometropia and dependent upon the amblyogenic factor. This suggests a direct link between the development of higher-order optical characteristics of the human eye and visual feedback. The results from these experiments have shown that a high degree of symmetry exists between the fellow eyes of non-amblyopic myopic anisometropes for a range of biomechanical, biometric and optical parameters for different levels of accommodation and following near work. While a single specific optical or biomechanical factor that is consistently associated with asymmetric refractive error development has not been identified, the findings from these studies suggest that further research into the association between ocular dominance, choroidal thickness and higher-order aberrations with anisometropia may improve our understanding of refractive error development.

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PPP is a general term covering all contracted relationships between the public and private sectors to produce a public asset or to deliver a public service. Its major advantage lies in utilising resources from the private sector to alleviate some of the financial burdens of the government. The Asian financial turmoil in the late 1990s has imposed enormous pressure on the budget of the Hong Kong Special Administrative Region (HKSAR) Government. With a continuous outcry for better public services due to the rapid development of Hong Kong, alternative financing models need to be sought to ensure sustainability. Hong Kong has the advantage of being the international gateway to Mainland China, and with this benefit has attracted overseas enterprises to base their offices in Hong Kong for the Asian market. Obviously the private sector has much to contribute. The HKSAR Government has realised the benefits of using PPP in Hong Kong as well as the success achieved overseas. But a more thorough research is needed to develop the most suitable practice of PPP in terms of project nature, project complexity, project type and project scale under which PPP is most appropriate for Hong Kong. This paper provides an initial report of a research project being funded by the Research Grants Council (RGC) of the HKSAR. The project aims to evaluate the benefits and risks of PPP adopted in Australia and the United Kingdom, and from these previous experiences to develop a best practice framework for implementing PPP in Hong Kong. It firstly reports on the status of PPP development trend and the hands-on experiences which have been drawn in these countries. Qualitative and quantitative research methods applied in conducting the research are discussed. The likely impacts of the study are highlighted. It is believed that the construction industry and the government would benefit a lot as a result of this study, and further procurement and project financing options would be opened up for delivering better future public service.

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This paper reports on a six month longitudinal study exploring people’s emotional experience with two categories of portable interactive devices (PIDs); media and health related PIDs. The focus is on emotions and how PIDs mediate these experiences in everyday contexts. Previous findings presented by the authors (Gomez 2009, 2010) revealed that people’s emotional experiences with PIDs over time are influenced by whether interactions were at a personal or social level. This paper presents four categories of activities identified and their relationship to emotional experiences with PIDs that have been developed through further analysis of the data. It concludes with a discussion of the findings and their implications to the field of Design on the design of future PIDs.

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The existing Collaborative Filtering (CF) technique that has been widely applied by e-commerce sites requires a large amount of ratings data to make meaningful recommendations. It is not directly applicable for recommending products that are not frequently purchased by users, such as cars and houses, as it is difficult to collect rating data for such products from the users. Many of the e-commerce sites for infrequently purchased products are still using basic search-based techniques whereby the products that match with the attributes given in the target user's query are retrieved and recommended to the user. However, search-based recommenders cannot provide personalized recommendations. For different users, the recommendations will be the same if they provide the same query regardless of any difference in their online navigation behaviour. This paper proposes to integrate collaborative filtering and search-based techniques to provide personalized recommendations for infrequently purchased products. Two different techniques are proposed, namely CFRRobin and CFAg Query. Instead of using the target user's query to search for products as normal search based systems do, the CFRRobin technique uses the products in which the target user's neighbours have shown interest as queries to retrieve relevant products, and then recommends to the target user a list of products by merging and ranking the returned products using the Round Robin method. The CFAg Query technique uses the products that the user's neighbours have shown interest in to derive an aggregated query, which is then used to retrieve products to recommend to the target user. Experiments conducted on a real e-commerce dataset show that both the proposed techniques CFRRobin and CFAg Query perform better than the standard Collaborative Filtering (CF) and the Basic Search (BS) approaches, which are widely applied by the current e-commerce applications. The CFRRobin and CFAg Query approaches also outperform the e- isting query expansion (QE) technique that was proposed for recommending infrequently purchased products.

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Retail employees are amongst the most vulnerable workers in the context of neoliberal market economies. In many countries, low paid retail employees comprise around 10 per cent of the workforce (ABS 2011). The retail labour market is typically highly feminised and youthful, with many employees in part time and various forms of precarious employment (Tailby & Pollert 2011). However, the industry and its trade unions have rarely been the focus of academic study (Tilly & Carré 2011). This paper thus aims to analyse and compare trade union strategies in the retail industry in Australia and New Zealand, by utilising findings from a larger comparative study. The respective unions studied are the Shop Distributive and Allied Workers Union (SDA) in Australia and the National Distribution Union (NDU) in New Zealand. Data from interviews with union officials at different levels and from different regional locations in Australia and NZ are analysed. Union policy documents are also utilised to support the empirical data. Key findings from the comparison of retail unions’ strategy in Australia and NZ include: 1) the importance of institutional factors and internal political differences in shaping and constraining union strategies; 2) different emphases on external relationships and variations in partnership approaches; 3) the need to recruit to ‘stand still’ by retail unions in both countries; and, 4) similarities and differences in the unions’ organising approaches. The paper concludes by examining the implications of these findings for retail unions’ strategic choices and their ability to deliver workplace justice for employees.

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Existing algebraic analyses of the ZUC cipher indicate that the cipher should be secure against algebraic attacks. In this paper, we present an alternative algebraic analysis method for the ZUC stream cipher, where a combiner is used to represent the nonlinear function and to derive equations representing the cipher. Using this approach, the initial states of ZUC can be recovered from 2^97 observed words of keystream, with a complexity of 2^282 operations. This method is more successful when applied to a modified version of ZUC, where the number of output words per clock is increased. If the cipher outputs 120 bits of keystream per clock, the attack can succeed with 219 observed keystream bits and 2^47 operations. Therefore, the security of ZUC against algebraic attack could be significantly reduced if its throughput was to be increased for efficiency.

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Both the SSS and SOBER-t32 stream cipher designs use a single word-based shift register and a nonlinear filter function to produce keystream. In this paper we show that the algebraic attack method previously applied to SOBER-t32 is prevented from succeeding on SSS by the use of the key dependent substitution box (SBox) in the nonlinear filter of SSS. Additional assumptions and modifications to the SSS cipher in an attempt to enable algebraic analysis result in other difficulties that also render the algebraic attack infeasible. Based on these results, we conclude that a well chosen key-dependent substitution box used in the nonlinear filter of the stream cipher provides resistance against such algebraic attacks.

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The formation of a venture relies, in part, upon the participants reaching a shared understanding of purpose and process. Yet in circumstances of great complexity and uncertainty how can such a shared understanding be created? If the response to complexity and uncertainty is to seek simplicity in order to find commonality then what is lost and what is at risk? Can shared understandings of purpose and process be arrived at by embracing complexity and uncertainty and if so how? These questions led us to explore the process of dialogue and communication of a team in its formative stages. Our interests were not centred upon the behavioural characteristics of the individuals in the 'forming' stage of group dynamics but rather the process of cognitive and linguistic turns, the wax and wan of ideas and, the formation of shared meaning. This process of cognitive and linguistic turns was focused thematically on the areas of foresight, innovation, entrepreneurship, and public policy. This cross disciplinary exploration sought to explore potential synergies between these domains, in particular in developing a conceptual basis for long term thinking that can inform wiser public policy.

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By 2020 Australia‟s National Digital Economy Strategy aims to increase household online participation and engage 12 per cent of all employees in teleworking arrangements. Achieving these goals is generally perceived as positive due to the reduced impact on the natural environment from less use of transport. However, this also will enable greater flexibility as to where people live and thus will impact upon the maintenance and formation of communities and on property use. This paper commences by clarifying what is Australia‟s internet economy before highlighting the impact of the internet on community formation and maintenance. The paper concludes by identifying what the achievement of these goals will mean for property use in the future.

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Right now, there are thousands of brand new PhD candidates entering universities around the country. Many of them will be highly anxious, knowing that they have a long, difficult journey ahead of them which, statistically speaking, they have less than a 75 per cent chance of completing successfully...

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Every February new mature age students attend an orientation to University workshop for non-school leavers. The results of an end of semester follow up questionnaire sent to attendees was collated and the main factors contributing to and detracting from first year success are presented in this paper.

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2010 marked the completion of data collection for year three (Wave 3) of the CAUSEE study. This report uses data from the first three years. Australia's population is noted for its mixed international background. The ABS 2006 census reports showed that almost a quarter of Australian population were born overseas, contributing to a high degree of cultural diversity. This report examines the international background and experience of Australian business founders as well as their aspired and actual participation in international markets. In this research briefing paper, we compare Nascent Firm (NF) and Young Firm (YF) groups and also 'Regular' start-ups in both categories with their High Potential counterparts. When we compare characteristics at one point in time and we compare developments over time. Unless otherwise stated the findings we comment on are 'statistically significant'. That is, there is less than 5 per cent risk that they would appear by chance if there is no true difference in the population form which the samples were drawn.

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Retrofit projects are different from newly-built projects in many respects. A retrofit project involves an existing building, which imposes constraints on the owners, designers, operators and constructors throughout the project process. Retrofit projects are risky, complex, less predictable and difficult to be well planned, which need greater coordination. For office building retrofit project, further restrictions will apply as these buildings often locate in CBD areas and most have to remain operational during the progression of project work. Issues such as site space, material storage and handling, noise and dust, need to be considered and well addressed. In this context, waste management is even more challenging with small spaces for waste handling, uncertainties in waste control, and impact of waste management activities on project delivery and building occupants. Current literatures on waste management in office building retrofit projects focus on increasing waste recovery rate based on project planning, monitoring and stakeholders’ collaboration. However, previous research has not produced knowledge of understanding the particular retrofit processes and their impact on waste generation and management. This paper discusses the interim results of a continuing research on new strategies for waste management in office building retrofit projects. Firstly based on the literature review, it summarizes the unique characteristics of office building retrofit projects and their influence on waste management. An assumption on waste management strategies is formed. Semi-structured interviews were conducted towards industry practitioners and findings are then presented in the paper. The assumption of the research was validated in the interviews from the opinions and experiences of the respondents. Finally the research develops a process model for waste management in office building retrofit projects. It introduces two different waste management strategies. For the dismantling phase, waste is generated fast along with the work progress, so integrated planning for project delivery and waste generation is needed in order to organize prompt handling and treatment. For the fit-out phase, the work is similar as new construction. Factors which are particularly linked to generating waste on site need to be controlled and monitored. Continuing research in this space will help improve the practice of waste management in office building retrofit projects. The new strategies will help promote the practicality of project waste planning and management and stakeholders’ capability of coordinating waste management and project delivery.

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Clinicians regularly face the confronting challenge of differentiating a choroidal naevus from a melanoma. Uveal naevi are a relatively common finding during routine eye examinations: a prevalence of 6.5 per cent has been reported.1 In contrast, malignant melanomata are uncommon, being found in six persons per million population, but they can have devastating implications and consequences.2 Differential diagnoses can be difficult to make with certainty; any additional information that can assist in this process is advantageous...