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The descriptions of the new products listed in this section are based on information supplied to us by the manufacturers.PHYSICS TODAY can assume no responsibility for their accuracy. For more information about a particular produc...
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The descriptions of the new products listed in this section are based on information supplied to us by the manufacturers.PHYSICS TODAY can assume no responsibility for their accuracy. For more information about a particular product, visit the website at the end of the product description.
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We show a way to take measurements of an additive quantity on several objects that gives the possibility to get considerably better accuracy of results than that one can get when the measurements are performed on particular object...
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We show a way to take measurements of an additive quantity on several objects that gives the possibility to get considerably better accuracy of results than that one can get when the measurements are performed on particular objects one by one, when the same instrument is used in both cases. The theory of such measurements is described and the possible gain in accuracy derived. When n velence 4-6 objects are to be measured, the uncertainty of combined measurement can be lowered by better than 2-4 times, respectively. Theoretical predictions were found to agree with both real and computer simulated measurements.
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Information quantity is an important moderator of personality judgment accuracy. Some evidence suggests that the amount of available information is positively related to accuracy. The current study utilized the social accuracy mod...
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Information quantity is an important moderator of personality judgment accuracy. Some evidence suggests that the amount of available information is positively related to accuracy. The current study utilized the social accuracy model to investigate the effects of differences in thin slices of information quantity on the distinctive accuracy and normativity of personality trait judgments. It was hypothesized that distinctive accuracy and normativity would increase as information quantity increased. Participants were 431 individuals who participated in an online study that varied the length of stimulus target observations (30 seconds, 1 minute, 3 minutes, and 5 minutes), after which judges rated targets using other-report measures of the Big Five personality traits. For all traits combined, significant levels of accuracy were found for all observation lengths, but distinctive accuracy and normativity did not increase as video length increased. Findings varied for individual traits. For distinctive accuracy, there was a linear increase with information quantity for Extraversion and a non-linear relationship for Conscientiousness, while there was a linear decrease for Openness. For normativity, there was a linear increase with information quantity for Agreeableness and a non-linear relationship for Conscientiousness. There are important differences in how observation length affects distinctive accuracy and normativity for different personality traits. (c) 2019 European Association of Personality Psychology
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Are some people truly better able to accurately perceive the personality of others? Previous research suggests that the good judge may be of little practical importance and individual differences minimal. In four large samples we ...
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Are some people truly better able to accurately perceive the personality of others? Previous research suggests that the good judge may be of little practical importance and individual differences minimal. In four large samples we assessed whether expressive accuracy (the good target) is a necessary condition for perceptive accuracy (the good judge) to emerge. As predicted from Funder's (1995) realistic accuracy model, assessments of the good judge predicted increased impression accuracy in the context of judgments of the good target. In contrast, evaluative tendencies for judges did not evidence a similar interaction; the positivity of impressions did not reliably increase as a function of how positively targets tend to be viewed. The present results suggest the good judge does indeed exist-some individuals are much better able to detect and utilize valid cues from targets-but this is only strongly evident when perceiving a good target.
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The accuracy of measurement instruments, as well as that of their components, gradually declines as time goes on. Due to different loss mechanisms and the allowable accuracy loss values, the accuracy lifetimes of a whole system an...
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The accuracy of measurement instruments, as well as that of their components, gradually declines as time goes on. Due to different loss mechanisms and the allowable accuracy loss values, the accuracy lifetimes of a whole system and its components are generally nonuniform, which lead to the waste of resources and costs. In this paper, a novel design method based on the uniform accuracy lifetime principle is presented to avoid the waste of resources. After giving and determining the uniformity and accuracy loss weights, optimal design models are established, and the sequential quadratic programming (SQP) method is employed to solve the models. A design example is presented to verify the effectiveness of the design model and the solution method. Using this method, the minimum accuracy lifetime of the whole system extends from 73.07 weeks to 200 weeks, and the uniformity improves from 0.75 to 0.96. The proposed method can be used in practice to achieve the target of uniform accuracy lifetimes for measurement systems because it is easy for manufacturers to obtain the average loss velocities of different components. The implementation of the optimization method will greatly help to save resources and improve the utilization efficiency of instruments or equipment.
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In this paper an investigation is made of the properties and use of two aggregate measures of forecast bias and accuracy. These are metrics used in business to calculate aggregate forecasting performance for a family (group) of pr...
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In this paper an investigation is made of the properties and use of two aggregate measures of forecast bias and accuracy. These are metrics used in business to calculate aggregate forecasting performance for a family (group) of products. We find that the aggregate measures are not particularly informative if some of the one-step-ahead forecasts are biased. This is likely to be the case in practice if frequently employed forecasting methods are used to generate a large number of individual forecasts. In the paper, examples are constructed to illustrate some potential problems in the use of the metrics. We propose a simple graphical display of forecast bias and accuracy to supplement the information yielded by the accuracy measures. This support includes relevant box-plots of measures of individual forecasting success. This tool is simple but helpful as the graphic display has the potential to indicate forecast deterioration that can be masked by one or both of the aggregate metrics. The procedures are illustrated with data representing sales of food items. Copyright 0 (c) 2005 John Wiley & Sons, Ltd.
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Classification of terrestrial materials using remotely sensed imagery is becoming an increasingly popular method to assess natural systems. This study uses predictions derived from remotely sensed hyperspectral images to determine...
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Classification of terrestrial materials using remotely sensed imagery is becoming an increasingly popular method to assess natural systems. This study uses predictions derived from remotely sensed hyperspectral images to determine minimum target detection thresholds and to statistically constrain classification accuracies. Minimum detection thresholds are determined using an iterative regression breakpoint technique, and accuracy is delineated by quantifying the variance above the correlation breakpoint. Assessing confidence and determining detection limits generates a greater understanding of the classification process and adds significant utility to the classified product. (c) 2006 Elsevier Inc. All rights reserved.
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Metacognitive monitoring is a complex psychological construct materialized in the metacognitive judgments that a subject may perform before or after covering a cognitive task.The accuracy,biases and variability of the judgments on...
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Metacognitive monitoring is a complex psychological construct materialized in the metacognitive judgments that a subject may perform before or after covering a cognitive task.The accuracy,biases and variability of the judgments on the correctness of answers reflects the quality of the metacognitive monitoring.This study highlights the relation between the accuracy of metacognitive monitoring at the local and global level,as well as the academic performance of students who attend the pedagogical study programme.The results highlight the relevance of an explicit and sustained metacognitive training of students.
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Mapping and tracking invasive alien plant species (IAPS) and their invasiveness can be achieved using remote sensing (RS) and geographic information systems (GIS). Continuous monitoring using RS, GIS and modelling are fundamental ...
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Mapping and tracking invasive alien plant species (IAPS) and their invasiveness can be achieved using remote sensing (RS) and geographic information systems (GIS). Continuous monitoring using RS, GIS and modelling are fundamental tools for informing invasion and management strategies. Using systematic comparisons, we look at three remote sensing imagery platforms and how accurately they can be classified within the Vhembe biosphere reserve, Limpopo Province, South Africa. Supervised classification of National Geospatial Information Colour Digital Aerial Imagery, DigitalGlobe Worldview 2 and CNES SPOT 6 was performed. The Spectral Angle Mapper (SAM) algorithm was used to identify the best satellite for species-level classification. The accuracy of the classifications produced an overall accuracy (OA) of 71% with a Kappa coefficient (KC) of 0.76 for CDA photographs, an OA of 81% and a KC of 0.80 for Worldview 2, and an OA of 89% with a KC of 0.86 for SPOT 6 imagery. Therefore, SPOT 6 imagery came out as the most suitable for species-level classification. The classification results from the SPOT 6 imagery were used as input data for further species distribution modelling of Mauritius Thorn and River Red Gum in the VBR.
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In this paper, we extend the use of automatic rezoning to viscous flow in two dimensions. In a previous paper, we tested th is technique on inviscid flow, with very good results. To simulate viscosity, we follow Fishelov's idea of...
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In this paper, we extend the use of automatic rezoning to viscous flow in two dimensions. In a previous paper, we tested th is technique on inviscid flow, with very good results. To simulate viscosity, we follow Fishelov's idea of explicitly taking the Laplacian of the cutoff function, but unlike Fishelov we use a moving grid. This eliminates the need to approximate the gradient of the vorticity, but rezoning needs to be used to keep the discretization error low. We first test the method on a radial ly symmetric problem where the exact vorticity is known for all time. Using both an eighth order cutoff function and an infinite order cutoff function, we obtain low errors and high rates of convergence. Then, we calculate the evolution of two circular vortex patches and of a square vorticity patch. The exact solution for the last two problems is not known, In all test problems we use a viscosity coefficient of 0.0005. (C) 1996 Academic Press, Inc. [References: 15]
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