990 resultados para unsignalised intersection


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In this paper we present some formulae for topological invariants of projective complete intersection curves with isolated singularities in terms of the Milnor number, the Euler characteristic and the topological genus. We also present some conditions, involving the Milnor number and the degree of the curve, for the irreducibility of complete intersection curves.

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Journalism needs advertising and advertising needs journalism: advertising pays for good reporting just as good reporting attracts customers for advertising. Problems arise when the equation becomes unbalanced, such as during the recessions in the early part of the twenty-first century. This paper asks the key question of whether editorial managers and journalists are embracing convergence at this time for business reasons or to do better journalism. It begins from the perspective that media organisations around the world are adopting various forms of convergence, and along the way embracing a range of business models. Several factors are influencing and driving the adoption of convergence - also known as multiple-platform publishing. Principal among them are the media's desire to reach as wide an audience as possible, consumers who want access to news in a variety of forms and times (news 24/7), and editorial managers' drive to cut costs. The availability of relatively cheap digital technology facilitates the convergence process. Many journalists believe that because that technology makes it relatively easy to convert and distribute any form of content into another, it is possible to produce new forms of storytelling and consequently do better journalism. This paper begins by defining convergence (as much as it is possible to do so) and describing the key competing models. It then considers the environments that lead to easy introduction of convergence, followed by the factors that hinder it. Examples of converged media around the world are provided, and suggestions offered on how to introduce convergence. The paper concludes that successful convergence satisfies the twin aims of good journalism and good business practices.

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The direction and speed of motion of a one-dimensional (1-D) stimulus, such as a grating, presented within a circular aperture is ambiguous. This ambiguity, referred to as the Aperture Problem (Fennema & Thompson, 1979) results from (i) the inability to detect motion parallel to grating orientation, and (ii) the occlusion of border information, such as the ‘ends’ of the grating, by the surface forming the aperture, Adelson and Movshon's (1982) intcrsection-of-constraints (IOC) model of motion perception describes a two-stage method of disambiguating the motion of 1-D moving stimuli (e.g., gratings) to produce unambiguous motion of two-dimensional (2-D) objects (e.g., plaid patterns) made up of several 1-D components. Specifically, in the IOC model ambiguous 1-D motions extracted by Stage 1 component-selective mechanisms are integrated by Stage 2 pattern-selective mechanisms to produce unambiguous 2-D motion signals. ‘Integration’ in the context of the IOC model involves determining the single motion vector (i.e., combination of direction and speed) which is consistent with the I-D components of a 2-D object. Since the IOC model assumes that 2-D objects undergo pure translation (i.e., without distortion, rotation, etc.), the motion vector consistent with all 1-D components describes the motion of the 2-D object itself. Adelson and Movshon (1982) propose that neural implementation of the computation underlying the IOC model is reflected in the perception of coherent 2-D plaid motion reported when two separately-moving ‘component’ gratings are superimposed. Using these plaid patterns the present thesis assesses the IOC model in terms of its ability to account for the perception of 2-D motion in a variety of circumstances. In the first series of experiments it is argued that the unambiguous motion perceived for a single grating presented within a rectangular aperture (i.e., the Barberpole illusion; Wallach, 1976) reflects application of the IOC computation to the moving 1-D grating and the stationary boundary of the aperture. While contrary to the assumption which underlies the IOC model (viz., that integration occurs between moving 1-D stimuli), evidence consistent with the involvement of the IOC computation in mediating the Barberpole illusion (in which there is only one moving stimulus) is obtained by measuring plaid coherence as a function of aperture shape. It is found that rectangular apertures which bias perceived component motions in directions consistent with plaid direction facilitate plaid coherence, while rectangular apertures which bias perceived component motions in directions inconsistent with plaid direction disrupt plaid coherence. In the second series of experiments, perceived directions of motion of type I symmetrical, type I asymmetrical, and type II plaids are measured with the aim of investigating the deviations in plaid directions reported by Ferrera and Wilson (1990) and Yo and Wilson (1992). Perceived directions of both asymmetrical and type II plaids are shown to deviate away from lOC-predicted directions and towards mean component direction. Furthermore, the magnitude of these deviations is being proportional to the difference between lOC-predicted plaid direction and mean component direction. On the basis of these directional deviations, modification to the IOC model is proposed. In the modified IOC model it is argued that plaid perception involves (i) the activity of Stage 2 pattern-selective mechanisms (and the Stage 1 component-selective mechanisms which input into these pattern-selective mechanisms) involved in implementing the IOC computation, and (ii) component-selective mechanisms which influence plaid perception directly, and ‘extraneously’ to the IOC computation. In the third series of experiments the validity of this modified IOC model, as well as the validity of alternative one-stage models of plaid perception are assessed in relation to perceived directions of plaid-induced MAEs as a function of both plaid direction and mean component direction. It is found that plaid-induced MAEs are shifted away from directions opposite to lOC-predicted plaid direction towards the direction opposite to mean component direction. This pattern of results is taken to be consistent with the modified IOC model which predicts the activity, and adaptation both of mechanisms signalling plaid direction (via implementation of the IOC computation), and ‘extraneous-type’ component-selective mechanisms signalling component directions. Alternative one-stage models which predict the adaptation of only mechanisms signalling plaid direction (the feature-tracking model), or the adaptation only of mechanisms signalling component directions (the distribution-of-activity model), cannot account for the directions of plaid-induced MAEs reported. The ability of the modified IOC model to account for the perceived directions of (i) gratings in rectangular apertures, (ii) various types of plaid in circular apertures, and (iii) directions of plaid-induced MAEs, is interpreted as supporting the proposition that human motion perception is based on a parallel and distributed process involving Stage 2 pattern-selective mechanisms (and the Stage 1 component-selective mechanisms which input into these mechanisms) taken to implement the IOC computation, and component-selective mechanisms taken to provide an 'extraneous' direct contribution to motion perception.

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Contrary to popular belief, teenage mothers are a declining proportion of birthing women; however they receive much negative public attention. Of particular public concern is the high cost of supporting teenage mothers, in terms of financial, health and welfare resources. Historically, the typical founding mother of white Australia was single, but post-war changes in the family structure incorporated the expectation that children be born into two-parent households with the male as the breadwinner. Policy changes in the seventies saw the introduction of the Sole Parents Pension which meant that many birthing teenage women could choose to keep their infants rather than have a clandestine adoption or an enforced marriage. The parenting practices of teenage mothers have been criticised for being less than optimal, and mother and child are reported as being disadvantaged cognitively, psychosocially, and educationally. One widespread nursing service which provides support for new mothers in Victoria is the Maternal and Child Health Service; however, teenage mothers appear reluctant to use such services. Why this should be so became an important question for this research, since little is known about the parenting practices of teenage mothers. This study therefore sought to explore mothering from the perspective of five sole supporting teenage mothers each of whom had a child over six months of age. The research methodology took an interpretive ethnographic approach and was guided by feminist principles. The data were collected through repeated interviewing, participant observation, informal discussions with key informants, field notes and journalling. Data analysis was aided by the use of the software, program NUD-IST. It was found that the young women in this study each chose to give birth with full realisation that their existence was dependent on the Welfare State. Unanticipated, however, were the many structural barriers which made their lives cataclysmic, but these reinforced their determination to prove themselves worthy and capable mothers. The young women negotiated motherhood through a range of social supports and through maternal practice. Unquestionably, their social dependency on the welfare system forced them into marginal citizen status. Moreover, absolute and intrinsic poverty levels were experienced, brought about by inadequate welfare payments. Formal support agencies, such as the Maternal and Child Health nurses were rarely approached to provide childrearing support beyond the initial months following birthing, since the teenagers' basic needs such as shelter, food and clothing took precedence over their parenting needs. Additionally, some nurses were perceived to hold judgmental attitudes towards teenage mothers. It was far easier to forestall confrontation with nurses and the other 'older' women clientele by avoiding them. Thus XI they turned to charitable agencies who provided a safety net in the form of emergency supplies of money, food, or equipment. Informal networks of friends provided alternative modes of support when family help failed to materialise. The children, however, provided the young women with an opportunity to transform their lives by breaking free of the past, and by creating a new, mature existence for themselves. Despite being abandoned by family, friends, lovers and society, in the privacy and isolation of their own homes, they attempted to provide a more nurturing environment for their children than they themselves had received. Each bestowed unconditional maternal love on the child and were rewarded through the pleasures of watching their children grow and develop into worthwhile individuals. The children became the focus of their attention and their reason for living. In the course of their welfare dependency, the young women became public property, targets of surveillance, and were subjected to stigmatising and condescending public attitudes wherever they went. In this way, it was evident that they were an oppressed group, but each found ways of resisting. Rather than focussing on their oppressive or disabling lives, or dwelling on their disadvantaged status, the young women sought their identities as mature women through motherhood and by demonstrating that they could do this important job well. Through motherhood their lives had meaning and a sense of purpose. The thesis concludes that motherhood in the teenage years is difficult. However, if appropriate supports are made available, teenage mothers need be no different from non-teenage mothers. But with state resources shrinking, and their own resources limited, teenage mothers are disadvantaged. In some ways, this study showed that all levels of support were inadequate, although those provided through the charitable organizations were seen to be the most appropriate. This reflects the current policy of economic rationalism adopted by most Western liberal democracies in the 1980s and 1990s and no less by the former Keating Labor Government in Australia.

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This thesis reviews previous work done on both general partition graphs and existential partition graphs, which are a generalised form of general partition graphs, and extends some of the results.

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This article analyzes video testimonies recorded at the Jewish Holocaust Museum and Research Centre in Melbourne,Australia, which address the highly complex and sensitive issue of “privileged” Jews. The so-called privileged Jews include prisoners in the Nazi-operated camps and ghettos who held positions that gave them access to material and other benefits, while compelling them to act in ways that have been judged detrimental to fellow inmates. Although the issue of “privileged” Jews has been largely neglected, it relates to a crucial facet of the Holocaust and has vast implications for its aftermath. The ethical dilemmas facing these victims may be closely linked to what Lawrence Langer has termed choiceless choices, which challenge conventional notions of “judgment” and “responsibility.” This problem is also the primary subject of Auschwitz survivor Primo Levi’s essay titled “The Grey Zone,” which is arguably the most influential essay ever written on the Holocaust. Levi argues that one should abstain from judging individuals who confronted such extreme circumstances, positioning prisoners with “privileged” positions at the threshold of representation and understanding. However, moral evaluations of “privileged” Jews have a strong impact on Holocaust testimonies, whether these were constructed during the war or recorded long after the survivors’ experiences. The examples of video testimonies explored in this article reveal that this is particularly the case when interviewees are former “privileged” Jews and interviewers are themselves Holocaust survivors. The article argues that when confronted with such an emotionally and morally fraught issue, judgment may itself be seen as a “limit of representation.”

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In 21st-century public health, rapid urbanization and mental health disorders are a growing global concern. The relationship between diet, brain function and the risk of mental disorders has been the subject of intense research in recent years. In this review, we examine some of the potential socioeconomic and environmental challenges detracting from the traditional dietary patterns that might otherwise support positive mental health. In the context of urban expansion, climate change, cultural and technological changes and the global industrialization and ultraprocessing of food, findings related to nutrition and mental health are connected to some of the most pressing issues of our time. The research is also of relevance to matters of biophysiological anthropology. We explore some aspects of a potential evolutionary mismatch between our ancestral past (Paleolithic, Neolithic) and the contemporary nutritional environment. Changes related to dietary acid load, advanced glycation end products and microbiota (via dietary choices and cooking practices) may be of relevance to depression, anxiety and other mental disorders. In particular, the results of emerging studies demonstrate the importance of prenatal and early childhood dietary practices within the developmental origins of health and disease concept. There is still much work to be done before these population studies and their mirrored advances in bench research can provide translation to clinical medicine and public health policy. However, the clear message is that in the midst of a looming global epidemic, we ignore nutrition at our peril.

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Traffic signal controlling is one of the solutions to reduce the traffic congestion in cities. To set appropriate green times for traffic signal lights, we have applied Adaptive Neuro-Fuzzy Inference System (ANFIS) method in traffic signal controllers. ANFIS traffic signal controller is used for controlling traffic congestion of a single intersection with the purpose of minimizing travel delay time. The ANFIS traffic controller is an intelligent controller that learns to set an appropriate green time for each phase of traffic signal lights at the start of the phase and based on the traffic information. The controller uses genetic algorithm to tune ANFIS parameters during learning time. The results of the experiments show higher performance of the ANFIS traffic signal controller compared to three other traffic controllers that are developed as benchmarks. One of the benchmarks is GA-FLC (Araghi et al., 2014), next one is a fixed-FLC, and a fixed-time controller with three different values for green phase. Results show the higher performance of ANFIS controller.

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  This paper aims at optimally adjusting a set of green times for traffic lights in a single intersection with the purpose of minimizing travel delay time and traffic congestion. Fuzzy logic system (FLS) is the method applied to develop the intelligent traffic timing controller. For this purpose, an intersection is considered and simulated as an intelligent agent that learns how to set green times in each cycle based on the traffic information. The FLS controller (FLC) uses genetic algorithm to tune its parameters during learning phase. Finally, The performance of the intelligent FLC is compared with the performance of a FLC with predefined parameters and three simple fixed-time controller. Simulation results indicate that intelligent FLC significantly reduces the total delay in the network compared to the fixed-time method and FLC with manual parameter setting.

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Traffic congestion in urban roads is one of the biggest challenges of 21 century. Despite a myriad of research work in the last two decades, optimization of traffic signals in network level is still an open research problem. This paper for the first time employs advanced cuckoo search optimization algorithm for optimally tuning parameters of intelligent controllers. Neural Network (NN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) are two intelligent controllers implemented in this study. For the sake of comparison, we also implement Q-learning and fixed-time controllers as benchmarks. Comprehensive simulation scenarios are designed and executed for a traffic network composed of nine four-way intersections. Obtained results for a few scenarios demonstrate the optimality of trained intelligent controllers using the cuckoo search method. The average performance of NN, ANFIS, and Q-learning controllers against the fixed-time controller are 44%, 39%, and 35%, respectively.