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Temporal Dimension (temporal + dimension)
Selected AbstractsSpace-Time Hierarchical Radiosity with Clustering and Higher-Order WaveletsCOMPUTER GRAPHICS FORUM, Issue 2 2004Cyrille Damez Abstract We address in this paper the issue of computing diffuse global illumination solutions for animation sequences. The principal difficulties lie in the computational complexity of global illumination, emphasized by the movement of objects and the large number of frames to compute, as well as the potential for creating temporal discontinuities in the illumination, a particularly noticeable artifact. We demonstrate how space-time hierarchical radiosity, i.e. the application to the time dimension of a hierarchical decomposition algorithm, can be effectively used to obtain smooth animations: first by proposing the integration of spatial clustering in a space-time hierarchy; second, by using a higher-order wavelet basis adapted for the temporal dimension. The resulting algorithm is capable of creating time-dependent radiosity solutions efficiently. [source] European Union Constitution-Making, Political Identity and Central European ReflectionsEUROPEAN LAW JOURNAL, Issue 2 2005It analyses both the temporal and spatial dimensions of constitution-making and addresses the problems of political identity related to ethnic divisions and civic demos. It starts by summarising the major arguments supporting the Union's constitution-making project and emphasises the Union's symbolic power as a polity built on the principles of civil society and parliamentary democracy. The EU's official rejection of ethnically based political identity played an important symbolic role in post-Communist constitutional and legal transformations in Central Europe in the 1990s. In the following part, the text analyses the temporal dimension of the EU's identity-building and constitution-making and emphasises its profoundly future-oriented structure. The concept of identity as the ,future in process' is the only option of how to deal with the absence of the European demos. Furthermore, it initiates the politically much-needed constitution-making process. The following spatial analysis of this process emphasises positive aspects of the horizontal model of constitution-making, its elements in the Convention's deliberation and their positive effect on the Central European accession states. The article concludes by understanding the emerging European identity as a multi-level identity of civil political virtues surrounded by old loyalties and traditions, which supports the conversational model of liberal democratic politics, reflects the continent's heterogeneity and leads to the beneficial combination of universal principles and political realism. [source] Time and Work,Life Balance: The Roles of ,Temporal Customization' and ,Life Temporality'GENDER, WORK & ORGANISATION, Issue 5 2008Emma Roberts This article poses a challenge to the orthodox binary, conceptualization of work,life balance only made possible by relying on the widespread ,clock time' worldview, which understands employment practices in terms of the basic time = money equation. In particular, it is the balance metaphor which relies on a quantification of both work and life in order to make sense and can therefore be seen to be based on an understanding of time as a measurable and value-able unit. This article seeks to begin the exercise of examining the concept of work,life balance through a broader concept of the temporal dimension than simply limited quantitative notions. Two temporal themes are reported from a study which identified employees who had customized their working pattern to suit the various and multi-dimensional facets of their lifestyles and thereby successfully improved their work,life balance. Participants in this study demonstrated that an improved work,life balance is more about a mind-set that refuses to be dominated by a work temporality and is determined to create ,me time' rather than e.g. simply choosing a four day week or a part-time job. It is argued that the notion of work,life balance is more usefully conceptualized within a broader notion of ,livingscapes' which contain both elements of work and life and that as researchers, our challenge must be to reflect the complexity of this weave within our analyses of individuals' work,life balance. [source] A comparison of Granger causality and coherency in fMRI-based analysis of the motor systemHUMAN BRAIN MAPPING, Issue 11 2009Andrew S. Kayser Abstract The ability of functional MRI to acquire data from multiple brain areas has spurred developments not only in voxel-by-voxel analyses, but also in multivariate techniques critical to quantifying the interactions between brain areas. As the number of multivariate techniques multiplies, however, few studies in any modality have directly compared different connectivity measures, and fewer still have done so in the context of well-characterized neural systems. To focus specifically on the temporal dimension of interactions between brain regions, we compared Granger causality and coherency (Sun et al., 2004, 2005: Neuroimage 21:647,658, Neuroimage 28:227,237) in a well-studied motor system (1) to gain further insight into the convergent and divergent results expected from each technique, and (2) to investigate the leading and lagging influences between motor areas as subjects performed a motor task in which they produced different learned series of eight button presses. We found that these analyses gave convergent but not identical results: both techniques, for example, suggested an anterior-to-posterior temporal gradient of activity from supplemental motor area through premotor and motor cortices to the posterior parietal cortex, but the techniques were differentially sensitive to the coupling strength between areas. We also found practical reasons that might argue for the use of one technique over another in different experimental situations. Ultimately, the ideal approach to fMRI data analysis is likely to involve a complementary combination of methods, possibly including both Granger causality and coherency. Hum Brain Mapp, 2009. © 2009 Wiley-Liss, Inc. [source] Between the Rock and a Hard Place: In Support of (something like) a Reformed View of the EucharistINTERNATIONAL JOURNAL OF SYSTEMATIC THEOLOGY, Issue 2 2001Douglas Farrow In this article, Calvin's eucharistic theology is re-read in the light of Aquinas, Augustine, Irenaeus, Luther, Jean-Luc Marion, Graham Ward and Catherine Pickstock. It is found to have great strengths, sucessfully avoiding both static ideas of Christ's presence and individual nominalism, while allowing a prominent place for the Holy Spirit and room for the believer's faith. Calvin took account of the doctrine of the Ascension quite differently from Luther by stressing Christ's bodily absence from this world. The article argues that this dialectic of presence and absence would gain from giving it a temporal dimension, giving more weight to eschatology. [source] Radiation sensitivity increases with proliferation-associated telomere dysfunction in nontransformed human epithelial cellsAGING CELL, Issue 4 2009David Soler Summary Epidemiological studies have demonstrated age differences among human adults in susceptibility to radiation, with cancer cases attributable to radiation being more frequent for older individuals at time of exposure. In addition to the notion that susceptibility increases because of progressive decline in DNA monitoring and immunosurveillance, telomere function is now emerging as a new and important factor in modulating cellular and organism sensitivity to ionizing radiation. The link between telomeres and radiosensitivity is well-documented in humans, but the causal events remain elusive. In this paper, it is shown that irradiated human epithelial cells with short dysfunctional telomeres derived from normal mammary gland display elevated DNA damage. An approach identifying the specific chromosomes with critically shortened telomeres in each donor has allowed us to conclude that short dysfunctional telomeres in human epithelial cells join radiation-induced DNA broken ends, thus interfering with their efficient repair. These findings argue against telomeres participating as sensors or transducers of DNA damage, as previously suggested. Rather, our current findings give support to the idea that dysfunctional telomeres, by acting as an additional joining option, reduce the repair fidelity of DNA broken-ends induced by radiation throughout the genome. In the mammary gland, age-dependent telomere attrition due to epithelial turnover, together with the accretion of checkpoint deficiencies, might render the accumulation of short dysfunctional telomeres. This implies that the risks associated with mammography screening could be higher than previously assumed. Our results have the possibility of imprinting a temporal dimension onto radiation sensitivity, namely, that shortened telomeres in aged cells may more easily compromise normal tissue function in the elderly. [source] Real-time accelerated interactive MRI with adaptive TSENSE and UNFOLD,MAGNETIC RESONANCE IN MEDICINE, Issue 2 2003Michael A. Guttman Abstract Reduced field-of-view (FOV) acceleration using time-adaptive sensitivity encoding (TSENSE) or unaliasing by Fourier encoding the overlaps using the temporal dimension (UNFOLD) can improve the depiction of motion in real-time MRI. However, increased computational resources are required to maintain a high frame rate and low latency in image reconstruction and display. A high-performance software system has been implemented to perform TSENSE and UNFOLD reconstructions for real-time MRI with interactive, on-line display. Images were displayed in the scanner room to investigate image-guided procedures. Examples are shown for normal volunteers and cardiac interventional experiments in animals using a steady-state free precession (SSFP) sequence. In order to maintain adequate image quality for interventional procedures, the imaging rate was limited to seven frames per second after an acceleration factor of 2 with a voxel size of 1.8 × 3.5 × 8 mm. Initial experiences suggest that TSENSE and UNFOLD can each improve the compromise between spatial and temporal resolution in real-time imaging, and can function well in interactive imaging. UNFOLD places no additional constraints on receiver coils, and is therefore more flexible than SENSE methods; however, the temporal image filtering can blur motion and reduce the effective acceleration. Methods are proposed to overcome the challenges presented by the use of TSENSE in interactive imaging. TSENSE may be temporarily disabled after changing the imaging plane to avoid transient artifacts as the sensitivity coefficients adapt. For imaging with a combination of surface and interventional coils, a hybrid reconstruction approach is proposed whereby UNFOLD is used for the interventional coils, and TSENSE with or without UNFOLD is used for the surface coils. Magn Reson Med 50:315,321, 2003. Published 2003 Wiley-Liss, Inc. [source] An AFLP clock for absolute dating of shallow-time evolutionary history , too good to be true?MOLECULAR ECOLOGY, Issue 22 2009D. EHRICH A major drawback of Amplified Fragment Length Polymorphisms (AFLP) as genetic makers for phylogeographic studies is their lack of a temporal dimension. In a recent publication in Molecular Ecology, Kropf et al. (2009) proposed a molecular clock for AFLP. In this comment we evaluate the proposed approach both theoretically and empirically. A linear increase with time is a prerequisite to use a genetic distance as molecular clock. Testing the relationship between genetic distance and time in the data of Kropf et al. (2009) for linearity revealed that the relationship was in fact not linear for their pooled data, as well as for one of the three species analyzed. Also, the relationship was not linear in two new species, where divergence times could be inferred from macrofossils. When applying the proposed molecular clock to data from eight species, dates obtained were plausible in some cases, but very improbable in others. The suggested genetic distance was also influenced by intrapopulation genetic diversity, leading to a potential bias. In the future, investigations of AFLP mutation rates combined with phylogeographic modelling may contribute to adding a time scale to the understanding of AFLP data. [source] Reinterpretable Imager: Towards Variable Post-Capture Space, Angle and Time Resolution in PhotographyCOMPUTER GRAPHICS FORUM, Issue 2 2010Amit Agrawal Abstract We describe a novel multiplexing approach to achieve tradeoffs in space, angle and time resolution in photography. We explore the problem of mapping useful subsets of time-varying 4D lightfields in a single snapshot. Our design is based on using a dynamic mask in the aperture and a static mask close to the sensor. The key idea is to exploit scene-specific redundancy along spatial, angular and temporal dimensions and to provide a programmable or variable resolution tradeoff among these dimensions. This allows a user to reinterpret the single captured photo as either a high spatial resolution image, a refocusable image stack or a video for different parts of the scene in post-processing. A lightfield camera or a video camera forces a-priori choice in space-angle-time resolution. We demonstrate a single prototype which provides flexible post-capture abilities not possible using either a single-shot lightfield camera or a multi-frame video camera. We show several novel results including digital refocusing on objects moving in depth and capturing multiple facial expressions in a single photo. [source] The Politics of Vigilance in Southeastern NigeriaDEVELOPMENT AND CHANGE, Issue 4 2006David Pratten ABSTRACT This article argues that governance can be best analysed within modes of vigilance. Where recent work on the post-colonial state has emphasized the symbolic and practical constitution of the state through surveillance and spatialization, so in counterpoint, this analysis illustrates that social engagement with the state is based on conceptions of vigilance and practices of counter-surveillance with both spatial and temporal dimensions. Drawing on an ethnography of Annang youth associations in southeastern Nigeria, this analysis outlines how the micro-politics of vigilance are based on knowledge of the states' patrimonial ,ways of operating' and processes which define internal, localized rights, registers and styles of action. This argument is based on an analysis of popular responses to disorder which contribute to an ,insurgent' construction of the public realm in which groups marginalized and excluded challenge the logic, locations, patterns of discourse and constructions of the public good. [source] The Other Atlantic WorldHISTORY COMPASS (ELECTRONIC), Issue 1 2003Jason Ward Despite the common imagination of the early modern Atlantic World as centered in the British-dominated North Atlantic, a broader perspective reveals that there is in fact another Atlantic World which is both larger and older than the English version, and whose general history responds to global but not necessarily European currents of history.1 Locating that "other" Atlantic World requires that we rethink its spatial and temporal dimensions. [source] Spatial economics of biological control: investing in new releases of insects for earlier limitation of Paterson's curse in AustraliaAGRICULTURAL ECONOMICS, Issue 3 2002T.L. Nordblom Abstract Paterson's curse and related weeds (Echium spp.) were introduced as garden flowers before 1850 and have spread to over 30 million ha in southern Australia. Four hundred successful releases of crown weevil (M. lawatus) populations specifically targeting Echium spp. were made in the 1993,2000 period. Based on the timing, location and performance of these past releases of beneficial insects, spatially and temporally specific trajectories of biocontrol have been simulated. Insect populations established by the past releases are expected to cover expanding areas at densities sufficient to limit host Echium infestations only over the next 25-50 years. The present analysis tackles the questions of where and how many additional releases are economically justified to speed up this process. We identify 31 districts in which diminishing niches for further insect releases are projected over time, according to the locations of damaging weed infestations and the timing, location and numbers of past insect releases. Benefits of biocontrol are expressed in terms of the value of recovered pasture productivity, keyed to estimates of loss and to historical district livestock inventories converted to dry sheep equivalent (DSE) feed availability levels to which prices are applied. Expected marginal contributions of increments of new releases were simulated for each of the 31 districts, subject to the spacehime limitations of each niche. Our explicit accounting for the spatial and temporal dimensions has made possible the economically optimd targeting of new biocontrol releases. For example, at $12/DSE and a marginal cost of $2000 per release, with a discount rate of l0%, we find there is a case for a program of over 400 new releases targeted to 17 districts, with as few as five releases to each of several and as many as 70 releases in one district. [source] An efficient high-order algorithm for solving systems of reaction-diffusion equationsNUMERICAL METHODS FOR PARTIAL DIFFERENTIAL EQUATIONS, Issue 3 2002Wenyuan Liao Abstract An efficient higher-order finite difference algorithm is presented in this article for solving systems of two-dimensional reaction-diffusion equations with nonlinear reaction terms. The method is fourth-order accurate in both the temporal and spatial dimensions. It requires only a regular five-point difference stencil similar to that used in the standard second-order algorithm, such as the Crank-Nicolson algorithm. The Padé approximation and Richardson extrapolation are used to achieve high-order accuracy in the spatial and temporal dimensions, respectively. Numerical examples are presented to demonstrate the efficiency and accuracy of the new algorithm. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 340,354, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/num.10012 [source] "Do You Have Anything to Add?"ANTHROPOLOGY & HUMANISM, Issue 1 2000Commentary on the Social Experience of Mental Illness, Narrative as Reflection This article argues that a phenomenological study of mental illness constructed from first-person subjective narratives can make a substantial contribution to our understanding of illness in terms of ordinary human experience. I suggest that the social experience of mental illness is primarily one of alienation and that this is both an internal and externally imposed experience. I conclude by proposing that the anthropological perspective,seeing the person within his or her wider cultural context, including both spatial and temporal dimensions,has the potential to generate new insights into how we might mitigate the alienating and depersonalizing effects of the mental illness experience. On another level, this article represents my attempt, as a mother, to come to terms with a mental health crisis within my own family. [source] | |||||||||||||