4,413 research outputs found

    One-dimensional simulation of temperature and moisture in atmospheric and soil boundary layers

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    Meteorologists are interested in modeling the vertical flow of heat and moisture through the soil in order to better simulate the vertical and temporal variations of the atmospheric boundary layer. The one dimensional planetary boundary layer model of is modified by the addition of transport equations to be solved by a finite difference technique to predict soil moisture

    Theoretical studies of the transport and removal processes of Sahara dust

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    The processes controlling the evolution of aerosol particles may be divided into dynamic processes concerned with the motions of air currents and microphysical processes concerned with the growth of the individual particles. The Ames planetary boundary layer model was modified to construct a subsynoptic scale aerosol model to study the long term fate of the Saharan dust. The transport model consists of a mixed layer, a convection layer, and free atmosphere. Conditions used for a preliminary test run and results obtained are described

    Reflections on the Scientific Legacy of Sergej S. Zilitinkevich on PBL and Urban Parameterizations in NWP Models

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    The paper summarizes many of the scientific achievements of Professor Sergej S. Zilitinkevich (1936–2021). It first focuses on his basic and applied atmospheric boundary layer research contributions. It then reviews their applications within research and operational numerical weather prediction and air quality modeling, showing their contribution to solving modeling problems related to extremely-stable and -unstable boundary layers

    The Complexity of Helly-B1B_{1} EPG Graph Recognition

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    Golumbic, Lipshteyn, and Stern defined in 2009 the class of EPG graphs, the intersection graph class of edge paths on a grid. An EPG graph GG is a graph that admits a representation where its vertices correspond to paths in a grid QQ, such that two vertices of GG are adjacent if and only if their corresponding paths in QQ have a common edge. If the paths in the representation have at most kk bends, we say that it is a BkB_k-EPG representation. A collection CC of sets satisfies the Helly property when every sub-collection of CC that is pairwise intersecting has at least one common element. In this paper, we show that given a graph GG and an integer kk, the problem of determining whether GG admits a BkB_k-EPG representation whose edge-intersections of paths satisfy the Helly property, so-called Helly-BkB_k-EPG representation, is in NP, for every kk bounded by a polynomial function of ∣V(G)∣|V(G)|. Moreover, we show that the problem of recognizing Helly-B1B_1-EPG graphs is NP-complete, and it remains NP-complete even when restricted to 2-apex and 3-degenerate graphs

    Could parental rules play a role in the association between short sleep and obesity in young children?

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    Short sleep duration is associated with obesity in young children. This study develops the hypothesis that parental rules play a role in this association. Participants were 3-year-old children and their parents, recruited at nursery schools in socioeconomically deprived and non-deprived areas of a North-East England town. Parents were interviewed to assess their use of sleep, television-viewing and dietary rules, and given diaries to document their child's sleep for 4 days/5 nights. Children were measured for height, weight, waist circumference and triceps and subscapular skinfold thicknesses. One-hundred and eight families participated (84 with complete sleep data and 96 with complete body composition data). Parental rules were significantly associated together, were associated with longer night-time sleep and were more prevalent in the non-deprived-area compared with the deprived-area group. Television-viewing and dietary rules were associated with leaner body composition. Parental rules may in part confound the association between night-time sleep duration and obesity in young children, as rules cluster together across behavioural domains and are associated with both sleep duration and body composition. This hypothesis should be tested rigorously in large representative samples

    Beliefs and expectancies in legal decision making: an introduction to the Special Issue

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    This introduction describes what the co-editors believe readers can expect in this Special Issue. After beliefs and expectancies are defined, examples of how these constructs influence human thought, feeling, and behavior in legal settings are considered. Brief synopses are provided for the Special Issue papers on beliefs and expectancies regarding alibis, children’s testimony behavior, eyewitness testimony, confessions, sexual assault victims, judges’ decisions in child protection cases, and attorneys’ beliefs about jurors’ perceptions of juvenile offender culpability. Areas for future research are identified, and readers are encouraged to discover new ways that beliefs and expectancies operate in the legal system

    The Use of Reaction Kinetics in Classifying Alkali Silica Reactivity Potential of Aggregates

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    The Australian Standard accelerated mortar bar test (AMBT) method, AS 1141.60.1, adopts the expansion limits at two exposure periods to classify the alkali silica reactivity (ASR) of aggregate. This was a first step toward the use of ‘reaction kinetics’ or ‘rate of reaction’ to detect and classify alkali silica reactivity. The AS 1141.60.2 concrete prism test (CPT), on the other hand, uses a single expansion limit at one year to classify ASR. This paper examines the validity of the use of reaction kinetics, evaluated from the AMBT expansion data, to gauge and classify the reactivity. This may enable a better quantification of the degrees of reactivity and a more fundamental approach to ASR mitigatio

    Mugshot Exposure Effects: Retroactive Interference, Mugshot Commitment, Source Confusion, and Unconscious Transference

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    More than 25 years of research has accumulated concerning the possible biasing effects of mugshot exposure to eyewitnesses. Two separate metaanalyses were conducted on 32 independent tests of the hypothesis that prior mugshot exposure decreases witness accuracy at a subsequent lineup. Mugshot exposure both significantly decreased proportion correct and increased the false alarm rate, the effect being greater on false alarms. A mugshot commitment effect, arising from the identification of someone in a mugshot, was a substantial moderator of both these effects. Simple retroactive interference, where the target person is not included among mugshots and no one in a mugshot is present in the subsequent lineup, did not significantly impair target identification. A third metaanalysis was conducted on 19 independent tests of the hypothesis that failure of memory for facial source or context results in transference errors. The effect size was more than twice as large for “transference” studies involving mugshot exposure in proximate temporal context with the target than for “bystander” studies with no subsequent mugshot exposure

    Evaluating megaprojects: from the “iron triangle” to network mapping

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    Evaluation literature has paid relatively little attention to the specific needs of evaluating large, complex industrial and infrastructure projects, often called ‘megaprojects’. The abundant megaproject governance literature, in turn, has largely focused on the so-called ‘megaproject pathologies’, i.e. the chronic budget overruns, and failure of such projects to keep to timetables and deliver the expected social and economic benefits. This article draws on these two strands of literature, identifies shortcomings, and suggests potential pathways towards an improved evaluation of megaprojects. To counterbalance the current overemphasis on relatively narrowly defined accountability as the main function of megaproject evaluation, and the narrow definition of project success in megaproject evaluation, the article argues that conceptualizing megaprojects as dynamic and evolving networks would provide a useful basis for the design of an evaluation approach better able to promote learning and to address the socio economic aspects of megaprojects. A modified version of ‘network mapping’ is suggested as a possible framework for megaproject evaluation, with the exploration of the multiple accountability relationships as a central evaluation task, designed to reconcile learning and accountability as the central evaluation functions. The article highlights the role of evaluation as an ‘emergent’ property of spontaneous megaproject ‘governing’, and explores the challenges that this poses to the role of the evaluator

    Take Me Out In A Velie Car

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    https://digitalcommons.library.umaine.edu/mmb-vp/6353/thumbnail.jp
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