895 resultados para Practical Advice for Entrepreneurs
Resumo:
We investigate a collision-sensitive secondary network that intends to opportunistically aggregate and utilize spectrum of a primary network to achieve higher data rates. In opportunistic spectrum access with imperfect sensing of idle primary spectrum, secondary transmission can collide with primary transmission. When the secondary network aggregates more channels in the presence of the imperfect sensing, collisions could occur more often, limiting the performance obtained by spectrum aggregation. In this context, we aim to address a fundamental query, that is, how much spectrum aggregation is worthy with imperfect sensing. For collision occurrence, we focus on two different types of collision: one is imposed by asynchronous transmission; and the other by imperfect spectrum sensing. The collision probability expression has been derived in closed-form with various secondary network parameters: primary traffic load, secondary user transmission parameters, spectrum sensing errors, and the number of aggregated sub-channels. In addition, the impact of spectrum aggregation on data rate is analysed under the constraint of collision probability. Then, we solve an optimal spectrum aggregation problem and propose the dynamic spectrum aggregation approach to increase the data rate subject to practical collision constraints. Our simulation results show clearly that the proposed approach outperforms the benchmark that passively aggregates sub-channels with lack of collision awareness.
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THE UPDATED second edition of this text begins with an overview of theories underpinning loss and grief, followed by a comprehensive outline of the author’s ‘range of response to loss’ (RRL) model, which emerged from her own research and experience. The RRL model provides a framework to explore variability in how people respond to grief, and case studies are used to demonstrate its application in practice. This is followed by an outline of the author’s ‘adult attitude to grief’ scale, which can be used to map a person’s grief and generate a grief profile.
Resumo:
In an attempt to elucidate people’s own imaginings and hopes for the future, I consider the relationship between the following concepts and activities: imagining; the future; hope; the existential human condition; and practical activity. I ask: ‘How do people experience and act on a desire for a different future?’
Resumo:
Perfect information is seldom available to man or machines due to uncertainties inherent in real world problems. Uncertainties in geographic information systems (GIS) stem from either vague/ambiguous or imprecise/inaccurate/incomplete information and it is necessary for GIS to develop tools and techniques to manage these uncertainties. There is a widespread agreement in the GIS community that although GIS has the potential to support a wide range of spatial data analysis problems, this potential is often hindered by the lack of consistency and uniformity. Uncertainties come in many shapes and forms, and processing uncertain spatial data requires a practical taxonomy to aid decision makers in choosing the most suitable data modeling and analysis method. In this paper, we: (1) review important developments in handling uncertainties when working with spatial data and GIS applications; (2) propose a taxonomy of models for dealing with uncertainties in GIS; and (3) identify current challenges and future research directions in spatial data analysis and GIS for managing uncertainties.
Resumo:
The emergence of open innovation theory and practice, alongside the evolution to a quadruple helix system of innovation, has led to a need for universities to rethink their models of engagement with industry and wider society. One important element in this system is the entrepreneurial academics; however there is a lack of research considering the motivations of entrepreneurial academics, who differ from academic entrepreneurs, to engage in knowledge transfer in line with open innovation policy. This research offers practical insights on whether new models of engagement, increasingly offered by universities, really address the policy drivers for open innovation. Furthermore, this research explores whether these activities might motivate entrepreneurial academics to participate. Preliminary findings identify that many supposedly new collaboration activities do not really motivate entrepreneurial academics. This may have important implications on the ability of universities to become truly open and to encourage their academics to become engaged in collaboration and impact.
Resumo:
Realising memory intensive applications such as image and video processing on FPGA requires creation of complex, multi-level memory hierarchies to achieve real-time performance; however commerical High Level Synthesis tools are unable to automatically derive such structures and hence are unable to meet the demanding bandwidth and capacity constraints of these applications. Current approaches to solving this problem can only derive either single-level memory structures or very deep, highly inefficient hierarchies, leading in either case to one or more of high implementation cost and low performance. This paper presents an enhancement to an existing MC-HLS synthesis approach which solves this problem; it exploits and eliminates data duplication at multiple levels levels of the generated hierarchy, leading to a reduction in the number of levels and ultimately higher performance, lower cost implementations. When applied to synthesis of C-based Motion Estimation, Matrix Multiplication and Sobel Edge Detection applications, this enables reductions in Block RAM and Look Up Table (LUT) cost of up to 25%, whilst simultaneously increasing throughput.
Development of a new welfare assessment protocol for practical application in long-term dog shelters
Resumo:
In many European shelters, dogs may spend many years confined. A poor environment and inappropriate management may lead to a low quality of life. The absence of harmonised European regulatory frameworks defining the minimum requirements for shelter facilities makes the definition of welfare standards for kennelled dogs challenging. Here, a new protocol was developed and tested to help identify the main welfare issues for shelter dogs. Twenty-six indicators were identified including management, resource and animal based measures. Accuracy and interobserver reliability were checked between four assessors. The protocol was applied in 29 shelters (n=1308 dogs) in six European countries. Overall prevalence of poor health conditions was below 10%. Test-retest reliability and validity of the protocol were investigated with encouraging results. A logistic regression was carried out to assess the potential of the protocol as a tool to identify welfare hazards in shelter environments. Inappropriate space allowance, for example, was found to be a risk factor potentially affecting the animal's cleanliness, skin condition and body condition. The protocol was designed to be concise and easy to implement. Systematic data collection could help identify welfare problems that are likely to arise in certain shelter designs and thus determine improvement in animal care standards.
Resumo:
Diagnosis of glaucoma and delivery of effective treatment is difficult everywhere, but additional challenges are evident in less affluent parts of the world, where the largest numbers of patients with this disease are living. The problems of providing good glaucoma care are examined with especial reference to south-east Asia including China and India and countries in sub-Saharan Africa. The relatively low priority given to glaucoma by vision-related and other nongovernmental organizations (NGOs) due to difficulties faced in delivering effective glaucoma screening and therapeutic interventions are discussed, together with possible future directions for increasing resources and priority for glaucoma care in poor areas.
Resumo:
Researchers have proposed 1-factor, 2-factor, and bifactor solutions to the 12-item Consideration of Future Consequences Scale (CFCS-12). In order to overcome some measurement problems and to create a robust and conceptually useful two-factor scale the CFCS-12 was recently modified to include two new items and to become the CFCS-14. Using a University sample, we tested four competing models for the CFCS-14: (a) a 12-item unidimensional model, (b) a model fitted for two uncorrelated factors (CFC-Immediate and CFC-Future), (c) a model fitted for two correlated factors (CFC-I and CFC-F), and (d) a bifactor model. Results suggested that the addition of the two new items has strengthened the viability of a two factor solution of the CFCS-14. Results of linear regression models suggest that the CFC-F factor is redundant. Further studies using alcohol and mental health indicators are required to test this redundancy.
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The Portuguese National Statistical Institute intends to produce estimations for the mean price of the habitation transation.
Resumo:
A previous paper showed that young children performed better when working as individuals rather than in pairs on a drill and practice program. This paper reports an analysis of behaviour and talk for individuals and single sex pairs using a computer-based drill and practice activity to explain differences in performance. Results indicated that individuals were more likely to be task-focused and to complete tasks successfully than children working in pairs. Differences were found in off-task activity, behaviours and type of talk. Grouping and verbal interaction are discussed in relation to the type of task/program that children are asked to undertake, and how both task and peer presence may constrain the child's task focus and performance when reinforcing pre-existing knowledge.