Inverse optimal transport

Discrete optimal transportation problems arise in various contexts in engineering, the sciences and the social sciences. Often the underlying cost criterion is unknown, or only partly known, and the observed optimal solutions are corrupted by noise. In this paper we propose a systematic approach to infer unknown costs from noisy observations of optimal transportation plans. The algorithm requires only the ability to solve the forward optimal transport problem, which is a linear program, and to generate random numbers. It has a Bayesian interpretation, and may also be viewed as a form of stochastic optimization. We illustrate the developed methodologies using the example of international migration flows. Reported migration flow data captures (noisily) the number of individuals moving from one country to another in a given period of time. It can be interpreted as a noisy observation of an optimal transportation map, with costs related to the geographical position of countries. We use a graph-based formulation of the problem, with countries at the nodes of graphs and non-zero weighted adjacencies only on edges between countries which share a border. We use the proposed algorithm to estimate the weights, which represent cost of transition, and to quantify uncertainty in these weights

Parameter estimation for macroscopic pedestrian dynamics models from microscopic data

In this paper we develop a framework for parameter estimation in macroscopic pedestrian models using individual trajectories -- microscopic data. We consider a unidirectional flow of pedestrians in a corridor and assume that the velocity decreases with the average density according to the fundamental diagram. Our model is formed from a coupling between a density dependent stochastic differential equation and a nonlinear partial differential equation for the density, and is hence of McKean--Vlasov type. We discuss identifiability of the parameters appearing in the fundamental diagram from trajectories of individuals, and we introduce optimization and Bayesian methods to perform the identification. We analyze the performance of the developed methodologies in various situations, such as for different in- and outflow conditions, for varying numbers of individual trajectories and for differing channel geometries

A Comparison of Two Self-Conception Disparity Methods as Operationalized within an Adolescent Population

It is posited that self-conception disparity is the amount of difference between an individual\u27s ideal self-conception and his or her real self-conception. Such a postulation arises directly from the literature wherein the self-concept is conceptualized as a multitude of self-conceptions an individual has. During the evaluative phase (i.E., the comparison of the ideal self-conception against the real self-conception), an image (self-image) of one\u27s self is evoked. This self-image is associated with an affective response referred to as self-Esteem. Two methods of computing self-conception disparity are compared and contrasted: (a) the often-used subtraction-Absolute Value Method and (b) a ratio method based on the work of James (1890) conceptualizing self esteem as the quotient of one\u27s successes to his or her pretensions. Results of the study indicate that the two methods share only a minimal amount of common variance, thus suggesting that they are either not measuring what they purport or that they may be accounting for different phenomena relative to self-esteem. In comparing the two methods for their ability to predict common external variables that have been correlated with self-esteem, the results indicate that the Ratio Method accounts for a greater proportion of the variance than does the Subraction-Absolute Value Formula. While more research is certainly needed to ferret out the question regarding which method of calculating self-conception disparity is of greatest utility, the results of this study suggest that the Ratio Method appears to lend itself more accurately to conceptualizing the nature of self-conception disparity

Inverse optimal transport

Discrete optimal transportation problems arise in various contexts in engineering, the sciences, and the social sciences. Often the underlying cost criterion is unknown, or only partly known, and the observed optimal solutions are corrupted by noise. In this paper we propose a systematic approach to infer unknown costs from noisy observations of optimal transportation plans. The algorithm requires only the ability to solve the forward optimal transport problem, which is a linear program, and to generate random numbers. It has a Bayesian interpretation and may also be viewed as a form of stochastic optimization. We illustrate the developed methodologies using the example of international migration flows. Reported migration flow data captures (noisily) the number of individuals moving from one country to another in a given period of time. It can be interpreted as a noisy observation of an optimal transportation map, with costs related to the geographical position of countries. We use a graph-based formulation of the problem, with countries at the nodes of graphs and nonzero weighted adjacencies only on edges between countries which share a border. We use the proposed algorithm to estimate the weights, which represent cost of transition, and to quantify uncertainty in these weights

Uncertainty, responsibility, and reassurance in paediatric palliative care: A conversation analytic study of telephone conversations between parents and clinicians

Background: Families play a vital role in the day-to-day medical care of children with life-limiting conditions. Navigating their child’s symptoms, treatments, and the possibility of sudden deteriorations, presents myriad challenges and can be distressing for the family. Paediatric palliative care can provide crucial support for families who are typically responsible for many aspects of their child’s care. Aim: To understand how paediatric palliative care clinicians use reassurance to support families through the uncertainties associated with caring for their children. Methods: One hundred routine telephone conversations between parents and clinicians of a paediatric palliative care service were recorded and analysed using Conversation Analytic methods. Findings: When parents report uncertainty about a specific care task, imply a causal link between this care task and an adverse outcome for their child, and a moral responsibility for the outcome, clinicians respond with reassurance. Clinicians produce reassurance through refuting parents’ accounts and providing an explanation to reframe the potential adverse outcome as independent of parent actions. Parents often agree with the clinicians’ reframings and demonstrate being reassured. Discussion: Specialist paediatric palliative care clinicians routinely foreground support for family members through reassurance. Conclusions: This study demonstrates how family-centred care can be accomplished in clinical practice

A new approach for characterization of steel weld metal hydrogen cracking susceptibility

Please click Additional Files below to see the full abstrac

Reducing patient delay with symptoms of acute coronary syndrome:a research protocol for a systematic review of previous interventions to investigate which behaviour change techniques are associated with effective interventions

Introduction: Delay to presentation with symptoms of acute coronary syndrome (ACS) is common meaning many fail to achieve optimal benefit from treatments. Interventions have had variable success in reducing delay. Evidence suggests inclusion of behaviour change techniques (BCTs) may improve effectiveness of interventions but this has not yet been systematically evaluated. Data from other time-critical conditions may be relevant.Methods and analysis: A systematic review will be undertaken to identify which BCTs are associated with effective interventions to reduce patient delay (or prompt rapid help-seeking) among people with time-critical conditions (eg, chest pain, ACS, lumps, stroke, cancer and meningitis). A systematic search of a wide range of databases (including Cochrane Library, MEDLINE, EMBASE, CINAHL, PsycInfo) and grey literature will be undertaken to identify all relevant intervention studies (randomised controlled trials, controlled clinical trials and cohort studies). Two independent reviewers will screen abstracts to identify relevant studies, apply inclusion criteria to full papers, assess methodological quality and extract data.Primary outcome measure: Change in patient decision time BCTs reported in each of the included studies will be categorised and presented according to the latest reliable taxonomy. Results of included studies will be synthesised, exploring relationships between inclusion of each BCT and effectiveness of the overall intervention. Where possible, means and SDs for differences in delay time will be calculated and combined within meta-analyses to derive a standardised mean difference and 95% CI. Analysis of (1) all time-critical and (2) ACS-only interventions will be undertaken

Give Sorrow Words: The Meaning of Parental Bereavement

A fundamental tenet of hermeneutic phenomenology is that people seek to create meaning of their experience from the response sited within human consciousness. The focus of this study is on the world of the lived experience as it is interpreted by participants through memory and language as accessed by interviews in order to produce an understanding of the participants’ experience. Three participants were interviewed whose adult children had died as a result of an AIDS-related illness. The interviews were recorded and transcribed, and interwoven analyses sought to illustrate the participants’ lived experience of the phenomenon. An attempt was made to understand how the various phenomena relating to parental bereavement were reflected by participants in the interviews. Common themes included reactions to the knowledge of the illness, the experience of being with their dying child, coping with the pain of the loss, and spiritual and existential concerns. There are references to how others judge their grieving behaviour. Issues of retribution and punishment are prominent and these appear to place a particular burden of sorrow on the grieving parent. The study provided insight into the lived experience of bereavement and the forging of new meaning structures that can accommodate the loss. Indo-Pacific Journal of Phenomenology, Volume 5, Edition 2 December 200