1,872 research outputs found
Integrated risk/cost planning models for the US Air Traffic system
A prototype network planning model for the U.S. Air Traffic control system is described. The model encompasses the dual objectives of managing collision risks and transportation costs where traffic flows can be related to these objectives. The underlying structure is a network graph with nonseparable convex costs; the model is solved efficiently by capitalizing on its intrinsic characteristics. Two specialized algorithms for solving the resulting problems are described: (1) truncated Newton, and (2) simplicial decomposition. The feasibility of the approach is demonstrated using data collected from a control center in the Midwest. Computational results with different computer systems are presented, including a vector supercomputer (CRAY-XMP). The risk/cost model has two primary uses: (1) as a strategic planning tool using aggregate flight information, and (2) as an integrated operational system for forecasting congestion and monitoring (controlling) flow throughout the U.S. In the latter case, access to a supercomputer is required due to the model's enormous size
Possible Implications of Mandating Choice in Corporate Defined Benefit Plans
Defined benefit (DB) plans have been applauded as the mainstay of the US pension system for many years, but increasingly such plans have been replaced with defined contribution (DC) pensions. One exception to the downward DB spiral has been the development of âhybridâ plans. Technically, these are pensions where the benefit accrual is communicated as a lump sum and not in the form of an annuity as is done with traditional pensions. In the transition to this new plan structure, some employees at some firms have contended that they would have accumulated retirement benefits more quickly under the old DB plan â assuming they remained employed â than under the new hybrid design. In response, some legislators have attempted to force companies transitioning from a traditional DB to a hybrid plan to offer all workers the open-ended choice of remaining in the old DB plan, versus switching to the new hybrid plan. In this paper we explore some of the possible consequences of mandating plan choice in this fashion. We conclude that regulators seeking to mandate pension choice should take into account the potential undesirable outcomes of such a law
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Profiling the Emotional Peaks and Valleys in Stories of Cross-border Shopping
The stories that travellers tell provide valuable insight to tourism managers responsible for shaping travel experiences. Access to consumer stories has never been greater due to the rise of online forums, reviews, and blogs (Gretzel, Fesenmaier, Lee, & Tussyadiah, 2010). Yet, researchersâ ability to make sense of these stories is limited by current theoretical and methodological approaches. We contend that there is an opportunity to develop new approaches to measure customer experience using advanced text analysis and sentiment indices. Specifically, we use narrative theory to explain the importance of emotional peaks and valleys in stories and propose a natural language processing (NLP) approach to identify and profile the issues that greatly impact on travellersâ experiences. Our narrative text-analytic approach is demonstrated using interview data describing 428 cross-border shopping experiences
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Keep Exploring, Sharing, and Tweeting: Connecting Millennials, Social Media and Destination Canadaâs Brand
Social media has become a powerful influencer in its ability to sway customer intentions and behaviors in an online setting. Given the importance of social media and its users in acting as information spreaders and disseminators, particularly in the context of global tourism, the goal of this research is to profile and/or understand youth travellers within the context of their social media behaviour. Using latent class analysis which helps to identify unobserved subgroups within a population, this study utilizes the rich dataset offered by Destination Canada which gives valuable traveler-focused information across the globe, including Brazil, China, Australia, Germany, South Korea, United Kingdom, and more. The results of this quantitative analysis reveal important differences based on age, explorer types and lifestyles, and geographic location as it relates to Canadian travel behaviors. By understanding what motivates these millennial-aged travelers particularly, destinations can create an environment where their actions are better anticipated and encouraged. The contribution of this original research is an empirically-informed view of how travelers share their experiences via social media
A preliminary investigation into psychophysiological effects of threatening a perceptually embodied rubber hand in healthy human participants
Background and aims: Threatening a perceptually embodied rubber hand with noxious stimuli has been shown to generate levels of anxiety similar to that experienced when a real hand is threatened. The aim of this study was to investigate skin conductance response, self-reported anxiety and the incidence, type and location of sensations when a perceptually embodied rubber was exposed to threatening and non-threatening stimuli.
Methods: A repeated measures cross-over design was used whereby 20 participants (>18 years, 14 females) received a threatening (syringe needle) and non-threatening (soft brush) stimulus to a perceptually embodied rubber hand. Perceptual embodiment was achieved using a soft brush to synchronously stroke the participantâs real hand (out of view) and a rubber hand (in view). Then the investigator approached the rubber hand with a syringe needle (threat) or soft brush (non-threat).
Results: Repeated measures ANOVA found that approaching the perceptually embodied rubber hand with either stimulus produced statistically significant reductions in the rated intensity of response to the following questions (p<0.01): âHow strongly does it feel like the rubber hand is yours?â; âHow strongly does it feel like the rubber hand is part of your body?â; and âHow strongly does it feel you can move the rubber hand?â. However, there were no statistically significant differences in scores between needle and brush stimuli. Repeated measures ANOVA on skin conductance response found statistically significant effects for experimental Events (baseline; stroking; perceptual embodiment; stimuli approaching rubber hand; stimuli touching rubber hand; p<0.001) but not for Condition (needle versus brush p=0.964) or experimental Event x Condition interaction (p=0.160). Ten of the 20 participants (50%) reported that they experienced a sensation arising from the rubber hand when the rubber hand was approached and touched by either the needle and/or brush but these sensations lacked precision in location, timing, and nature.
Conclusion and Implications: Our preliminary findings suggest that the increase in arousal in response to stimuli entering the peripersonal space may not be selective for threat. There was tentative evidence that more intense sensations were experienced when a perceptually embodied rubber hand was approached by a threatening stimulus. Our findings provide initial insights and should serve as a catalyst for further research
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From Hashtags to Shopping Bags: Measuring the Rise of eWOM through Social Media and its Impact on Travelersâ Shopping Patterns
The rise of the Internet and the proliferation of social media has amplified the importance of understanding the consumer decision-making process. Not surprisingly, travel industry marketers are devoting greater portions of their marketing budgets towards harnessing the power of social media and electronic word-of-mouth (eWOM) as a tool to influence consumer preferences. Yet, to accomplish this goal, marketers need to understand that people differ in their motivation to spread eWOM through social media, and there exists a crucial distinction between organic (consumer-initiated) versus incentivized (company-promoted) eWOM. Therefore, the objective of this study is to draw insights from the nascent eWOM literature and interviews with cross-border travelers to investigate heterogeneity in social media use and the differential impact on travel-related intentions and behaviours. Using a conceptual mapping methodology, our preliminary findings demonstrate patterns of social, opinion forming, and trip planning aspects. Implications for marketers are discussed
Justice Policy Reform for High-Risk Juveniles: Using Science to Achieve Large-Scale Crime Reduction
After a distinctly punitive era, a period of remarkable reform in juvenile crime regulation has begun. Practical urgency has fueled interest in both crime reduction and research on the prediction and malleability of criminal behavior. In this rapidly changing context, high-risk youth â the small proportion of the population where crime is concentrated â present a conundrum. Research indicates that these are precisely the individuals to intensively treat to maximize crime reduction, but there are both real and imagined barriers to doing so. Institutional placement or criminal court processing can exclude these youths from interventions that would better protect public safety. In this article, we synthesize relevant research to help resolve this challenge in a manner that is consistent with the lawâs core principles. In our view, adolescence offers unique opportunities for risk reduction that could (with modifications) be realized in the juvenile justice system in cooperation with other social institutions
Properties of the Scalar Universal Equations
The variational properties of the scalar so--called ``Universal'' equations
are reviewed and generalised. In particular, we note that contrary to earlier
claims, each member of the Euler hierarchy may have an explicit field
dependence. The Euler hierarchy itself is given a new interpretation in terms
of the formal complex of variational calculus, and is shown to be related to
the algebra of distinguished symmetries of the first source form.Comment: 15 pages, LaTeX articl
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A Bioconductor workflow for processing and analysing spatial proteomics data
Spatial proteomics is the systematic study of protein sub-cellular localisation. In this workflow, we describe the analysis of a typical quantitative mass spectrometry-based spatial proteomics experiment using the MSnbase and pRoloc Bioconductor package suite. To walk the user through the computational pipeline, we use a recently published experiment predicting protein sub-cellular localisation in pluripotent embryonic mouse stem cells. We describe the software infrastructure at hand, importing and processing data, quality control, sub-cellular marker definition, visualisation and interactive exploration. We then demonstrate the application and interpretation of statistical learning methods, including novelty detection using semi-supervised learning, classification, clustering and transfer learning and conclude the pipeline with data export. The workflow is aimed at beginners who are familiar with proteomics in general and spatial proteomics in particular.LMB and CMM are supported by a Wellcome Trust Technology Development Grant (grant number 108441/Z/15/Z). KSL is a Wellcome Trust Joint Investigator (110170/Z/15/Z). LG is supported by the BBSRC Strategic Longer and Larger grant (Award BB/L002817/1)
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