480 research outputs found

    Athenian Taxation from the Pisistratids to Lycurgus 550 325 ВС

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    In this thesis I respond to calls by historians for a study of ancient Athenian taxation. The thesis is in four parts. In Part One I identify sixteen or so taxes. The most important are an import/export tax and a wealth tax, but I argue that recent evidence suggests that there may have been a sales tax. I believe that I may have identified four new fragments of inscriptions relating to one of the sixteen or so taxes. I discuss in some detail two of the most important inscriptions discovered in recent years, the Grain-Tax Law and the Law on the Little Panathenaea. In Part Two I look at the administration of Athenian taxes and at the extent of the black economy (I believe that some coin hoards could be evidence of tax evasion). In Part Three, I identify, for comparative purposes, taxes in some other states and also examine tax agreements Athens and other states made with each other. Part Four looks at a number of central themes. First, the nature of Athenian taxes, where I argue that there is no real evidence that at least direct taxes were regarded by the Greeks as a form of tyranny or that this was the reason that there was no income tax. Second, Athenian taxation in a wider context, where I argue that it is not impossible that there were some taxes in the earlier part of the fifth century, and track the development of taxes during the fifth and fourth centuries. Third, coinage and the payment of taxes, where I argue that recent research on fractional coinage suggests that the payment of taxes was one of the reasons for the development of coinage in Athens. Fourth, the relationship of taxes with income from Empire/Confederacy where I argue that the two varied inversely with each other. Fifth, the contribution of taxes to the Athenian economy, where I argue that this could have amounted to between a quarter and a third of Athenian state income by the time of Lycurgus

    Leveraging Health: The Urban Planner’s Dilemma

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    In recent decades, a trend has emerged advancing the view that urban planning is a critical instrument for public health action. A popular concept now used to articulate this position is “healthy urban planning” (HUP). The concept of HUP adopts a human-centric philosophical perspective towards urban planning, one which emphasises human health and wellbeing. By positioning HUP and the urban planning-health interface as the point of departure, this thesis investigated the conceptual, epistemic and technical factors affecting the construction and mobilisation of the HUP concept, and the wider integration of health into urban planning. The study employed a qualitative, case study methodology with a social constructivist, postmodernist philosophy, acknowledging the multidimensional nature of knowledge and practice of urban planning within real socio-political contexts. The findings of the study reveal a funnel of contestation as one moves from the normative and policy spheres of HUP, within which its merits are not disputed, through to its theoretical and practical spheres, where conflict in meaning and understanding is both observable and arguably a natural response to the complex nature of the concept and its definition. The aim of HUP may appear straightforward and determined: to promote and not harm human health. However, such abstraction creates a binary that veils a complex relational web in which multiple structural, institutional and agential factors interact to construct novel interpretations of HUP and shape the relationship between health and urban planning. This research proposes that the concept of HUP does not have a discrete, universally accepted meaning. Instead, this same basic concept attracts multiple meanings. These meanings, moreover, do not simply vanish when contradicted by fact, authority, or competing theory, but often become more entrenched and their dismissal more vehemently resisted. There is, therefore, a need to view HUP as a “contested concept”, which far from lacking theoretical or policy-making purchase is valuable in promoting healthier forms of urban planning. In light of this, this thesis recommends that to secure the benefits of HUP in the long term there is a need to further clarify the concept’s definition, its use in urban planning practice, and to address the implications of both these aspects for research and theory development

    Stress-Energy Tensor for the Massless Spin 1/2 Field in Static Black Hole Spacetimes

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    The stress-energy tensor for the massless spin 1/2 field is numerically computed outside and on the event horizons of both charged and uncharged static non-rotating black holes, corresponding to the Schwarzschild, Reissner-Nordstrom and extreme Reissner-Nordstr\"om solutions of Einstein's equations. The field is assumed to be in a thermal state at the black hole temperature. Comparison is made between the numerical results and previous analytic approximations for the stress-energy tensor in these spacetimes. For the Schwarzschild (charge zero) solution, it is shown that the stress-energy differs even in sign from the analytic approximation. For the Reissner-Nordstrom and extreme Reissner-Nordstrom solutions, divergences predicted by the analytic approximations are shown not to exist.Comment: 5 pages, 4 figures, additional discussio

    Esterase Activity in Developing Pods of Soyheans

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    Four stages of soybean pod development of four varieties of Glycine max were surveyed for esterase enzymes by starch-gel electrophoresis. Differences in esterase banding patterns occur among the four varieties investigated. Enzyme changes accompanying pod development were observed. Pod collection procedure affected the number of esterase bands visible, with collection in dry ice giving more visible bands than did collection in regular ice

    ROC curves in cost space

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s10994-013-5328-9ROC curves and cost curves are two popular ways of visualising classifier performance, finding appropriate thresholds according to the operating condition, and deriving useful aggregated measures such as the area under the ROC curve (AUC) or the area under the optimal cost curve. In this paper we present new findings and connections between ROC space and cost space. In particular, we show that ROC curves can be transferred to cost space by means of a very natural threshold choice method, which sets the decision threshold such that the proportion of positive predictions equals the operating condition. We call these new curves rate-driven curves, and we demonstrate that the expected loss as measured by the area under these curves is linearly related to AUC. We show that the rate-driven curves are the genuine equivalent of ROC curves in cost space, establishing a point-point rather than a point-line correspondence. Furthermore, a decomposition of the rate-driven curves is introduced which separates the loss due to the threshold choice method from the ranking loss (Kendall τ distance). We also derive the corresponding curve to the ROC convex hull in cost space; this curve is different from the lower envelope of the cost lines, as the latter assumes only optimal thresholds are chosen.We would like to thank the anonymous referees for their helpful comments. This work was supported by the MEC/MINECO projects CONSOLIDER-INGENIO CSD2007-00022 and TIN 2010-21062-C02-02, GVA project PROMETEO/2008/051, the COST-European Cooperation in the field of Scientific and Technical Research IC0801 AT, and the REFRAME project granted by the European Coordinated Research on Long-term Challenges in Information and Communication Sciences & Technologies ERA-Net (CHIST-ERA), and funded by the Engineering and Physical Sciences Research Council in the UK and the Ministerio de Economia y Competitividad in Spain.Hernández Orallo, J.; Flach ., P.; Ferri Ramírez, C. (2013). ROC curves in cost space. Machine Learning. 93(1):71-91. https://doi.org/10.1007/s10994-013-5328-9S7191931Adams, N., & Hand, D. (1999). Comparing classifiers when the misallocation costs are uncertain. Pattern Recognition, 32(7), 1139–1147.Chang, J., & Yap, C. (1986). A polynomial solution for the potato-peeling problem. Discrete & Computational Geometry, 1(1), 155–182.Drummond, C., & Holte, R. (2000). Explicitly representing expected cost: an alternative to ROC representation. In Knowl. discovery & data mining (pp. 198–207).Drummond, C., & Holte, R. (2006). Cost curves: an improved method for visualizing classifier performance. Machine Learning, 65, 95–130.Elkan, C. (2001). The foundations of cost-sensitive learning. In B. Nebel (Ed.), Proc. of the 17th intl. conf. on artificial intelligence (IJCAI-01) (pp. 973–978).Fawcett, T. (2006). An introduction to ROC analysis. Pattern Recognition Letters, 27(8), 861–874.Fawcett, T., & Niculescu-Mizil, A. (2007). PAV and the ROC convex hull. Machine Learning, 68(1), 97–106.Flach, P. (2003). The geometry of ROC space: understanding machine learning metrics through ROC isometrics. In Machine learning, proceedings of the twentieth international conference (ICML 2003) (pp. 194–201).Flach, P., Hernández-Orallo, J., & Ferri, C. (2011). A coherent interpretation of AUC as a measure of aggregated classification performance. In Proc. of the 28th intl. conference on machine learning, ICML2011.Frank, A., & Asuncion, A. (2010). UCI machine learning repository. http://archive.ics.uci.edu/ml .Hand, D. (2009). Measuring classifier performance: a coherent alternative to the area under the ROC curve. Machine Learning, 77(1), 103–123.Hernández-Orallo, J., Flach, P., & Ferri, C. (2011). Brier curves: a new cost-based visualisation of classifier performance. In Proceedings of the 28th international conference on machine learning, ICML2011.Hernández-Orallo, J., Flach, P., & Ferri, C. (2012). A unified view of performance metrics: translating threshold choice into expected classification loss. Journal of Machine Learning Research, 13, 2813–2869.Kendall, M. G. (1938). A new measure of rank correlation. Biometrika, 30(1/2), 81–93. doi: 10.2307/2332226 .Swets, J., Dawes, R., & Monahan, J. (2000). Better decisions through science. Scientific American, 283(4), 82–87

    Baguette:towards end-to-end service orchestration in heterogeneous networks

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    Network services are the key mechanism for operators to introduce intelligence and generate profit from their infrastructures. The growth of the number of network users and the stricter application network requirements have highlighted a number of challenges in orchestrating services using existing production management and configuration protocols and mechanisms. Recent networking paradigms like Software Defined Networking (SDN) and Network Function Virtualization (NFV), provide a set of novel control and management interfaces that enable unprecedented automation, flexibility and openness capabilities in operator infrastructure management. This paper presents Baguette, a novel and open service orchestration framework for operators. Baguette supports a wide range of network technologies, namely optical and wired Ethernet technologies, and allows service providers to automate the deployment and dynamic re-optimization of network services. We present the design of the orchestrator and elaborate on the integration of Baguette with existing low-level network and cloud management frameworks

    Possible climate-related signals in high-resolution topography of lobate debris aprons in Tempe Terra, Mars

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    Lobate debris aprons are common features in the midlatitudes of Mars that are assumed to be the result of the flow of ice-rich material. We produce high-resolution digital elevation models of two of these features in the Tempe Terra region of Mars using HiRISE stereo images. We identify two main topographic features of different wavelength using a power spectrum analysis approach. Short wavelength features, between approximately 10 and 20 m in length, correspond to a polygonal surface texture present throughout our study area. Long wavelength features, between approximately 700 and 1800 m in length, correspond to broad ridges that are up to 20 m in amplitude. We interpret both topographic signals to be the likely result of climate change affecting the debris contribution and/or the flow regime of the lobate debris aprons. The apparent surface age of about 300 Ma could be evidence of an astronomical forcing mechanism recorded in these lobate debris aprons at this time in Mars' history. Citation: Grindrod, P. M., and S. A. Fawcett (2011), Possible climate-related signals in high-resolution topography of lobate debris aprons in Tempe Terra, Mars, Geophys. Res. Lett., 38, L19201, doi: 10.1029/2011GL049295

    Mental Toughness in South African Youth: Relationships With Forgivingness and Attitudes Towards Risk

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    Young people are particularly vulnerable to health risk behaviors and interpersonal violence, stimulating scholars’ attention towards identifying factors that may reduce the likelihood that these actions will occur. Associated with positive outcomes in a variety of domains, mental toughness in young people might protect them from engaging in potentially deleterious interpersonal or health-risk behaviors, while potentially promoting positive psychological behaviors. Within this framework, the present study investigated the relationships between mental toughness, attitudes towards physical and psychological risk-taking, and trait forgiveness in a sample of 123 (males = 54, females = 69) South African youth (M age = 23.97 years, SD = 4.46). Univariate and multivariate analyses indicated higher levels of mental toughness were associated with being more forgiving, (η2pηp2 = .036), perceiving physical risk-taking more positively (η2pηp2 = .062), but having more negative attitudes towards psychological risk-taking (η2pηp2 = .036). These findings give credence to mental toughness as a psychological characteristic involved in youth risk-taking perceptions and interpersonal functioning. Future research might explore the integration of mental toughness into the development of future youth risk behavior interventions

    Method to compute the stress-energy tensor for the massless spin 1/2 field in a general static spherically symmetric spacetime

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    A method for computing the stress-energy tensor for the quantized, massless, spin 1/2 field in a general static spherically symmetric spacetime is presented. The field can be in a zero temperature state or a non-zero temperature thermal state. An expression for the full renormalized stress-energy tensor is derived. It consists of a sum of two tensors both of which are conserved. One tensor is written in terms of the modes of the quantized field and has zero trace. In most cases it must be computed numerically. The other tensor does not explicitly depend on the modes and has a trace equal to the trace anomaly. It can be used as an analytic approximation for the stress-energy tensor and is equivalent to other approximations that have been made for the stress-energy tensor of the massless spin 1/2 field in static spherically symmetric spacetimes.Comment: 34 pages, no figure
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