378 research outputs found
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The modifier effect and property mutability
The modifier effect is the reduction in perceived likelihood of a generic property sentence, when the head noun is modified. We investigated the prediction that the modifier effect would be stronger for mutable than for central properties, without finding evidence for this predicted interaction over the course of five experiments. However Experiment 6, which provided a brief context for the modified concepts to lend them greater credibility, did reveal the predicted interaction. It is argued that the modifier effect arises primarily from a general lack of confidence in generic statements about the typical properties of unfamiliar concepts. Neither prototype nor classical models of concept combination receive support from the phenomenon
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On prototypes as defaults (Comment on Connolly, Fodor, Gleitman and Gleitman, 2007)
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The inverse conjunction fallacy
If people believe that some property is true of all members of a class such as sofas, then they should also believe that the same property is true of all members of a conjunctively defined subset of that class such as uncomfortable handmade sofas. A series of experiments demonstrated a failure to observe this constraint, leading to what is termed the inverse conjunction fallacy. Not only did people often express a belief in the more general statement but not in the more specific, but also when they accepted both beliefs, they were inclined to give greater confidence to the more general. It is argued that this effect underlies a number of other demonstrations of fallacious reasoning, particularly in category-based induction. Alternative accounts of the phenomenon are evaluated, and it is concluded that the effect is best interpreted in terms of intensional reasoning [Tversky, A., & Kahneman, D. (1983). Extensional versus intuitive reasoning: the conjunction fallacy in probability judgment. Psychological Review, 90, 293–315.]
Pipeline break detection using pressure transient monitoring
Sudden pipe breaks occur in water transmission pipelines and distribution mains. The consequences of these breaks can be very expensive because of the service interruption, the cost of repair, and damage to surrounding property and infrastructure. The costs associated with the pipeline breaks can be reduced by minimizing the break detection and location time. This paper presents a new continuous monitoring approach for detecting and locating breaks in pipelines. A sudden pipe break creates a negative pressure wave that travels in both directions away from the break point and is reflected at the pipeline boundaries. Using the pressure data measured at one location along the pipeline, the timing of the initial and reflected transient waves induced by the break determines the location of the break. The magnitude of the transient wave provides an estimate of the break size. The continuous monitoring technique uses a modified two-sided cumulative sum (CUSUM) algorithm to detect abrupt break-induced changes in the pressure data. The adaptive tuning of CUSUM parameters is implemented to detect breaks of differing sizes and opening times. The continuous monitoring technique is verified by using results from both laboratory and field experiments and shows potential for detecting and locating sudden breaks in real pipelines.Dalius Misiunas, John Vítkovský, Gustaf Olsson, Angus Simpson, M.ASCE, and Martin Lambert
The worldwide costs of dementia in 2019
Introduction: Dementia is a leading cause of death and disability globally. Estimating total societal costs demonstrates the wide impact of dementia and its main direct and indirect economic components. Methods: We constructed a global cost model for dementia, presenting costs as cumulated global and regional costs. Results: In 2019, the annual global societal costs of dementia were estimated at US 23,796 per person with dementia. Of the total, US 448.7 billion (34%) direct social sector costs (including long-term care), and US 1313.4 in 2019. Sixty-one percent of people with dementia live in low-and middle-income countries, whereas 74% of the costs occur in high-income countries. The impact of informal care accounts for about 50% of the global costs. The development of a long-term care infrastructure is a great challenge for low-and middle-income countries. There is a great need for more cost studies, particularly in low- and middle-income countries. Discussions of a framework for global cost comparisons are needed
Frequency domain analysis for detecting pipeline leaks
The original publication can be found at http://scitation.aip.org/hyoThis paper introduces leak detection methods that involve the injection of a fluid transient into the pipeline, with the resultant transient trace analyzed in the frequency domain. Two methods of leak detection using the frequency response of the pipeline are proposed. The inverse resonance method involves matching the modeled frequency responses to those observed to determine the leak parameters. The peak-sequencing method determines the region in which the leak is located by comparing the relative sizes between peaks in the frequency response diagram. It was found that a unique pattern was induced on the peaks of the frequency response for each specific location of the leak within the pipeline. The leak location can be determined by matching the observed pattern to patterns generated numerically within a lookup table. The procedure for extracting the linear frequency response diagram, including the optimum measurement position, the effect of unsteady friction, and the way in which the technique can be extended into pipeline networks, are also discussed within the paper.Pedro J. Lee, John P. Vítkovský, Martin F. Lambert, Angus R. Simpson and James A. Ligget
Dopant-dependent impact of Mn-site doping on the critical-state manganites: R0.6Sr0.4MnO3 (R=La, Nd, Sm, and Gd)
Versatile features of impurity doping effects on perovskite manganites,
SrMnO, have been investigated with varying the doing
species as well as the -dependent one-electron bandwidth. In
ferromagnetic-metallic manganites (=La, Nd, and Sm), a few percent of Fe
substitution dramatically decreases the ferromagnetic transition temperature,
leading to a spin glass insulating state with short-range charge-orbital
correlation. For each species, the phase diagram as a function of Fe
concentration is closely similar to that for SrMnO
obtained by decreasing the ionic radius of site, indicating that Fe doping
in the phase-competing region weakens the ferromagnetic double-exchange
interaction, relatively to the charge-orbital ordering instability. We have
also found a contrastive impact of Cr (or Ru) doping on a spin-glass insulating
manganite (=Gd). There, the impurity-induced ferromagnetic magnetization is
observed at low temperatures as a consequence of the collapse of the inherent
short-range charge-orbital ordering, while Fe doping plays only a minor role.
The observed opposite nature of impurity doping may be attributed to the
difference in magnitude of the antiferromagnetic interaction between the doped
ions.Comment: 7 pages, 6 figure
Independent Ion Migration in Suspensions of Strongly Interacting Charged Colloidal Spheres
We report on sytematic measurements of the low frequency conductivity in
aequous supensions of highly charged colloidal spheres. System preparation in a
closed tubing system results in precisely controlled number densities between
1E16/m3 and 1E19/m^3 (packing fractions between 1E-7 and 1E-2) and electrolyte
concentrations between 1E-7 and 1E-3 mol/l. Due to long ranged Coulomb
repulsion some of the systems show a pronounced fluid or crystalline order.
Under deionized conditions we find s to depend linearily on the packing
fraction with no detectable influence of the phase transitions. Further at
constant packing fraction s increases sublinearily with increasing number of
dissociable surface groups N. As a function of c the conductivity shows
pronounced differences depending on the kind of electrolyte used. We propose a
simple yet powerful model based on independent migration of all species present
and additivity of the respective conductivity contributions. It takes account
of small ion macro-ion interactions in terms of an effectivly transported
charge. The model successfully describes our qualitatively complex experimental
observations. It further facilitates quantitative estimates of conductivity
over a wide range of particle and experimental parameters.Comment: 32 pages, 17 figures, 2 tables, Accepted by Physical Review
Gate-tunable black phosphorus spin valve with nanosecond spin lifetimes
Two-dimensional materials offer new opportunities for both fundamental
science and technological applications, by exploiting the electron spin. While
graphene is very promising for spin communication due to its extraordinary
electron mobility, the lack of a band gap restricts its prospects for
semiconducting spin devices such as spin diodes and bipolar spin transistors.
The recent emergence of 2D semiconductors could help overcome this basic
challenge. In this letter we report the first important step towards making 2D
semiconductor spin devices. We have fabricated a spin valve based on ultra-thin
(5 nm) semiconducting black phosphorus (bP), and established fundamental spin
properties of this spin channel material which supports all electrical spin
injection, transport, precession and detection up to room temperature (RT).
Inserting a few layers of boron nitride between the ferromagnetic electrodes
and bP alleviates the notorious conductivity mismatch problem and allows
efficient electrical spin injection into an n-type bP. In the non-local spin
valve geometry we measure Hanle spin precession and observe spin relaxation
times as high as 4 ns, with spin relaxation lengths exceeding 6 um. Our
experimental results are in a very good agreement with first-principles
calculations and demonstrate that Elliott-Yafet spin relaxation mechanism is
dominant. We also demonstrate that spin transport in ultra-thin bP depends
strongly on the charge carrier concentration, and can be manipulated by the
electric field effect
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