625 resultados para positional advantage


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In estuaries and natural water channels, the estimate of velocity and dispersion coefficients is critical to the knowledge of scalar transport and mixing. This estimate is rarely available experimentally at sub-tidal time scale in shallow water channels where high frequency is required to capture its spatio-temporal variation. This study estimates Lagrangian integral scales and autocorrelation curves, which are key parameters for obtaining velocity fluctuations and dispersion coefficients, and their spatio-temporal variability from deployments of Lagrangian drifters sampled at 10 Hz for a 4-hour period. The power spectral densities of the velocities between 0.0001 and 0.8 Hz were well fitted with a slope of 5/3 predicted by Kolmogorov’s similarity hypothesis within the inertial subrange, and were similar to the Eulerian power spectral previously observed within the estuary. The result showed that large velocity fluctuations determine the magnitude of the integral time scale, TL. Overlapping of short segments improved the stability of the estimate of TL by taking advantage of the redundant data included in the autocorrelation function. The integral time scales were about 20 s and varied by up to a factor of 8. These results are essential inputs for spatial binning of velocities, Lagrangian stochastic modelling and single particle analysis of the tidal estuary.

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Background: Prediction of outcome after stroke is important for triage decisions, prognostic estimates for family and for appropriate resource utilization. Prognostication must be timely and simply applied. Several scales have shown good prognostic value. In Calgary, the Orpington Prognostic Score (OPS) has been used to predict outcome as an aid to rehabilitation triage. However, the OPS has not been assessed at one week for predictive capability. Methods: Among patients admitted to a sub-acute stroke unit, OPS from the first week were examined to determine if any correlation existed between final disposition after rehabilitation and first week score. The predictive validity of the OPS at one week was compared to National Institute of Health Stroke Scale (NIHSS) score at 24 hours using logistic regression and receiver operator characteristics analysis. The primary outcome was final disposition after discharge from the stroke unit if the patient went directly home, or died, or from the inpatient rehabilitation unit. Results: The first week OPS was highly predictive of final disposition. However, no major advantage in using the first week OPS was observed when compared to 24h NIHSS score. Both scales were equally predictive of final disposition of stroke patients, post rehabilitation. Conclusion: The first week OPS can be used to predict final outcome. The NIHSS at 24h provides the same prognostic information.

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This paper asks the question to what scale and speed does society need to reduce its ecological footprint and improve resource productivity to prevent further overshoot and return within the ecological limits of the earth’s ecological life support systems? How fast do these changes need to be achieved? The paper shows that now a large range of studies find that engineering sustainable solutions need to be roughly an order or magnitude resource productivity improvement (sometimes called a Factor of 10, or a 90% reduction) by 2050 to achieve real and lasting ecological sustainability. This marks a significant challenge for engineers – indeed all designers and architects, where best practice in engineering sustainable solutions will need to achieve large resource productivity targets. The paper brings together examples of best practice in achieving these large targets from around the world. The paper also highlights key resources and texts for engineers who wish to learn how to do it. But engineers need to be realistic and patient. Significant barriers exist to achieving Factor 4-10 such as the fact that infrastructure and technology rollover and replacement is often slow. This slow rollover of the built environment and technology is the context within which most engineers work, making the goal of achieving Factor 10 all the more challenging. However, the paper demonstrates that by using best practice in engineering sustainable solutions and by addressing the necessary market, information and institutional failures it is possible to achieve Factor 10 over the next 50 years. This paper draws on recent publications by The Natural Edge Project (TNEP) and partners, including Hargroves, K. Smith, M. (Eds) (2005) The Natural Advantage of Nations: Business Opportunities, Innovation and Governance for the 21st Century, and the TNEP Engineering Sustainable Solutions Program - Critical Literacies for Engineers Portfolio. Both projects have the significant support of Engineers Australia. its College of Environmental Engineers and the Society of Sustainability and Environmental Engineering.

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The last three decades have been difficult for companies and industry. In an increasingly competitive international business climate with shifting national environmental regulations, higher standards are being demanded by the consumer and community groups, not-to-mention the escalating cost of primary resources such as water, steel and minerals. The cause of these pressures is the traditional notion held by business executives and engineers that there is an inherent trade off between eco-efficiency and improving the economic bottom line. However there is significant evidence and examples of best practice to show that there is in fact no trade-off between the environment and the economy if sustainable development through continual improvement is adopted. It is highly possible therefore for companies to make a profitable transition towards sustainable business practice, where along the transition significant business opportunities can be taken advantage of. Companies are by their very nature dynamic, influential and highly capable of adapting to change. Making an organisational transformation to a sustainable business is not outside the capacity of the typical company, who know much of what is needed already to change their activities to satisfy current market demands while achieving competitiveness. However in order to make the transition towards sustainable business practice companies require some key mechanisms such as accurate information on methodologies and opportunities, understanding of the financial and non-financial incentives, permission from stakeholders and shareholders, understanding of the emerging market opportunities, a critical mass of leaders in their sector and demonstrated case studies, and awarding appropriate risk-taking activities undertaken by engineers and CEOs. Satisfying these requirements will adopt an innovative culture within the company that strives for continual improvement and successfully transforms itself to achieve competitiveness in the 21st Century. This paper will summarise the experiences of The Natural Edge Project (TNEP) and its partners in assisting organisations to make a profitable transition towards sustainable business practice through several initiatives. The Natural Advantage of Nations publication provides the critical information required by business leaders and engineers to set the context of sustainable business practice. The Profiting in a Carbon Constrained World report, developed with Natural Capitalism Inc led by Hunter Lovins, summarises the opportunities available to companies to take advantage of the carbon trading market mechanisms such as the Chicago Climate Exchange and European Climate Exchange. The Sustainability Helix then guides the company through the transition by identifying the key tools and methodologies required by companies to reduce environmental loading while dramatically improving resource productivity and achieving competitiveness. Finally, the Engineering Sustainable Solutions Program delivers the key engineering information required by companies and university departments to deliver sustainable engineering solutions. The initiatives are of varying complexity and level of application, however all are designed to provide key staff the critical information required to make a profitable transition towards sustainable business practice. It is then their responsibility to apply and teach their knowledge to the rest of the organisation.

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We used event-related fMRI to investigate the neural correlates of encoding strength and word frequency effects in recognition memory. At test, participants made Old/New decisions to intermixed low (LF) and high frequency (HF) words that had been presented once or twice at study and to new, unstudied words. The Old/New effect for all hits vs. correctly rejected unstudied words was associated with differential activity in multiple cortical regions, including the anterior medial temporal lobe (MTL), hippocampus, left lateral parietal cortex and anterior left inferior prefrontal cortex (LIPC). Items repeated at study had superior hit rates (HR) compared to items presented once and were associated with reduced activity in the right anterior MTL. By contrast, other regions that had shown conventional Old/New effects did not demonstrate modulation according to memory strength. A mirror effect for word frequency was demonstrated, with the LF word HR advantage associated with increased activity in the left lateral temporal cortex. However, none of the regions that had demonstrated Old/New item retrieval effects showed modulation according to word frequency. These findings are interpreted as supporting single-process memory models proposing a unitary strength-like memory signal and models attributing the LF word HR advantage to the greater lexico-semantic context-noise associated with HF words due to their being experienced in many pre-experimental contexts.

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We present a new algorithm to compute the voxel-wise genetic contribution to brain fiber microstructure using diffusion tensor imaging (DTI) in a dataset of 25 monozygotic (MZ) twins and 25 dizygotic (DZ) twin pairs (100 subjects total). First, the structural and DT scans were linearly co-registered. Structural MR scans were nonlinearly mapped via a 3D fluid transformation to a geometrically centered mean template, and the deformation fields were applied to the DTI volumes. After tensor re-orientation to realign them to the anatomy, we computed several scalar and multivariate DT-derived measures including the geodesic anisotropy (GA), the tensor eigenvalues and the full diffusion tensors. A covariance-weighted distance was measured between twins in the Log-Euclidean framework [2], and used as input to a maximum-likelihood based algorithm to compute the contributions from genetics (A), common environmental factors (C) and unique environmental ones (E) to fiber architecture. Quanititative genetic studies can take advantage of the full information in the diffusion tensor, using covariance weighted distances and statistics on the tensor manifold.

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We propose in this paper a new method for the mapping of hippocampal (HC) surfaces to establish correspondences between points on HC surfaces and enable localized HC shape analysis. A novel geometric feature, the intrinsic shape context, is defined to capture the global characteristics of the HC shapes. Based on this intrinsic feature, an automatic algorithm is developed to detect a set of landmark curves that are stable across population. The direct map between a source and target HC surface is then solved as the minimizer of a harmonic energy function defined on the source surface with landmark constraints. For numerical solutions, we compute the map with the approach of solving partial differential equations on implicit surfaces. The direct mapping method has the following properties: (1) it has the advantage of being automatic; (2) it is invariant to the pose of HC shapes. In our experiments, we apply the direct mapping method to study temporal changes of HC asymmetry in Alzheimer's disease (AD) using HC surfaces from 12 AD patients and 14 normal controls. Our results show that the AD group has a different trend in temporal changes of HC asymmetry than the group of normal controls. We also demonstrate the flexibility of the direct mapping method by applying it to construct spherical maps of HC surfaces. Spherical harmonics (SPHARM) analysis is then applied and it confirms our results on temporal changes of HC asymmetry in AD.

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Identifying genetic variants influencing human brain structures may reveal new biological mechanisms underlying cognition and neuropsychiatric illness. The volume of the hippocampus is a biomarker of incipient Alzheimer's disease and is reduced in schizophrenia, major depression and mesial temporal lobe epilepsy. Whereas many brain imaging phenotypes are highly heritable, identifying and replicating genetic influences has been difficult, as small effects and the high costs of magnetic resonance imaging (MRI) have led to underpowered studies. Here we report genome-wide association meta-analyses and replication for mean bilateral hippocampal, total brain and intracranial volumes from a large multinational consortium. The intergenic variant rs7294919 was associated with hippocampal volume (12q24.22; N = 21,151; P = 6.70 × 10 -16) and the expression levels of the positional candidate gene TESC in brain tissue. Additionally, rs10784502, located within HMGA2, was associated with intracranial volume (12q14.3; N = 15,782; P = 1.12 × 10 -12). We also identified a suggestive association with total brain volume at rs10494373 within DDR2 (1q23.3; N = 6,500; P = 5.81 × 10 -7).

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Although many immigrants enter the United States with a healthy body weight, this health advantage disappears the longer they reside in the United States. To better understand the complexities of obesity change within a cultural framework, a community-based participatory research (CBPR) approach, PhotoVoice, was used, focusing on physical activity among Muslim Somali women. The CBPR partnership was formed to identify barriers and resources to engaging in physical activity with goals of advocacy and program development. Muslim Somali women (n = 8) were recruited to participate, trained and provided cameras, and engaged in group discussions about the scenes they photographed. Participants identified several barriers, including safety concerns, minimal culturally appropriate resources, and financial constraints. Strengths included public resources and a community support system. The CBPR process identified opportunities and challenges to collaboration and dissemination processes. The findings laid the framework for subsequent program development and community engagement.

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Purpose This paper investigates the interrelationships between knowledge integration (KI), product innovation and capability development to enhance our understanding of how firms can develop capability at the firm level, which in turn enhances their performance. One of the critical underlying mechanisms for capability building identified in the literature is the role of knowledge integration, which operates within product innovation projects and contributes to dynamic capability development. Therefore, the main research question is “how does the integration of knowledge across product innovation projects lead to the development of capability?” Design/methodology/approach We adopted a case-based approach and investigated the case of a successful firm that was able to sustain its performance through a series of product innovation projects. In particular this research focused on the role of KI and firm-level capability development over the course of four projects, during which the firm successfully managed the transformation of its product base and renewal of its competitive advantage. For this purpose an in-depth case study of capability development was undertaken at the Iran Khodro Company (IKCO), the key player in the Iranian auto industry transformation. Originality/value This research revealed that along with changes at each level of product architecture “design knowledge” and “design capability” have been developed at the same level of product architecture, leading to capability development at that level. It can be argued that along the step by step maturation of radical innovation across the four case projects, architectural knowledge and capability have been developed at the case company, resulting in the gradual emergence of a modular product and capability architecture across different levels of product architecture. Such findings basically add to extensive emphasis in the literature on the interrelationship of the concept of modularity with knowledge management and capability development. Practical implications Findings of this study indicate that firms manage their knowledge in accordance with the level of specialization in knowledge and capability. Furthermore, firms design appropriate knowledge integration mechanisms within and among functions in order dynamically align knowledge processes at different levels of the product architecture. Accordingly, the outcomes of this study may guide practitioners in managing their knowledge processes, through dynamically employing knowledge integration modes step-by-step and from the part level to the architectural level of product architecture across a sequence of product innovation projects to encourage learning and radical innovation.

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Goodbye Brigadoon examines the shifting role media production plays in the economic and cultural strategies of global cities in small market nations, specifically Glasgow, Scotland. In particular, this project focuses on the formation of a digital media village along the banks of the River Clyde to argue the site constitutes a logical component to Glasgow’s ongoing transformation into a cosmopolitan center. Yet, as the regional government’s economic strategies and policy directives work to transform the abandoned waterfront into a center of cultural activity, this project also underscores the contradictory cultural dynamics to emerge from media production’s new role in the post-industrial city. At its core, the media hub reveals a regional government more interested in the technology used to deliver “national” stories than the manner of the stories themselves or the cultural practices responsible for creating them. Indeed, Goodbye Brigadoon is most interested in how media professionals based at the emergent cluster negotiate a sense of cultural identity and creative license against the institutional constraints, policy matters, and commercial logic they also must navigate in their workaday rituals. Ultimately, the conclusions offered in this project argue for a more complicated conception of the global-local location where these professionals work. Glasgow’s digital media village, in other words, is much more than an innocuous site of competitive advantage, urban regeneration, and job growth. It is best understood as a site of intense social struggle and unequal power relations where local mediamakers often find the site’s impetus for multiplatform media production an institutionally enforced false promise at odds with the realities of creative labor in the city.

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The system for high utilization of LNG cold energy is proposed by use of process simulator. The proposed design is a closed loop system, and composed by a Hampson type heat exchanger, turbines, pumps and advanced humid air turbine (AHAT) or Gas turbine combined cycle (GTCC). Its heat sources are Boil-off gas and cooling water for AHAT or GTCC. The higher cold exergy recovery to power can be about 38 to 56% as compared to the existing cold power generation of about 20% with a Rankine cycle of a single component. The advantage of the proposed system is to reduce the number of heat exchangers. Furthermore, the environmental impact is minimized because the proposed design is a closed loop system. A life cycle comparative cost is calculated to demonstrate feasibility of the proposed design. The development of the Hampson type exchangers is expected to meet the key functional requirements and will result in much higher LNG cold exergy recovery and the overall system performance i.e. re-gasification. Additionally, the proposed design is expected to provide flexibility to meet different gas pressure suited for the deregulation of energy system in Japan and higher reliability for an integrated boil-off gas system.

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Many firms initially face significant resource constraints during attempts to develop and grow (Shepherd et al., 2000). One promising theory that explicitly links to ways entrepreneurial firms respond to resource constraints is bricolage (Lévi-Strauss, 1966). Bricolage is defined as “making do by applying combinations of the resources at hand to new problems and opportunities” (Baker & Nelson, 2005, p. 333). Bricolage aligns with notions of resourcefulness: using what’s on hand, through making do, and recombining resources for new or novel purposes. Through a bias for action and a refusal to enact limitations on the resources that are available to create solutions, bricoleurs can tackle unexpected complex challenges, take advantage of opportunities, and go where most other firms won’t, in their attempts at firm development. Bricolage studies have previously not empirically examined the impact of bricolage on firm performance. Our work contributes to the emerging behavioral theory of bricolage by offering the first empirical test evaluating the impact of bricolage on early stage firm performance (i.e. venture emergence in nascent firms and sales in young firms). Using new product development (NPD) theories of speed of development, co-creation and innovativeness, we theorise that bricolage has a positive effect on early stage firm performance. We then introduce environmental dynamism as a moderator which influences this relationship.

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Current mobile devices and streaming video services support high definition (HD) video, increasing expectation for more contents. HD video streaming generally requires large bandwidth, exerting pressures on existing networks. New generation of video compression codecs, such as VP9 and H.265/HEVC, are expected to be more effective for reducing bandwidth. Existing studies to measure the impact of its compression on users’ perceived quality have not been focused on mobile devices. Here we propose new Quality of Experience (QoE) models that consider both subjective and objective assessments of mobile video quality. We introduce novel predictors, such as the correlations between video resolution and size of coding unit, and achieve a high goodness-of-fit to the collected subjective assessment data (adjusted R-square >83%). The performance analysis shows that H.265 can potentially achieve 44% to 59% bit rate saving compared to H.264/AVC, slightly better than VP9 at 33% to 53%, depending on video content and resolution.

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Diaphragm action of crest-fixed profiled steel claddings is present in low-rise buildings whether the designer acknowledges it or not. For the designers to take advantage of the diaphragm strength of the crest-fixed steel claddings in the design of low-rise buildings in a similar manner to valley-fixed claddings, and to design the buildings based on the true behaviour rather than the assumed behaviour, shear/racking behaviour of the three trapezoidal and corrugated steel claddings commonly used at present was investigated using large scale experiments. Crest-fixed claddings (up to a maximum size of 6 x 6.2m) with different aspect ratio and fastening systems were tested to failure, based on which suitable shear strength and stiffness values have been proposed for these claddings as they are used at present. A simple analytical model combined with basic connection data from small scale experiments was used to predict the shear strength of tested panels. Currently attempts are being made to develop general design formulae to determine shear strength and stiffness of crest-fixed steel claddings...