Resampling and Distribution of the Product Methods for Testing Indirect Effects in Complex Models     

Jason Williams  David P. MacKinnon 《Structural equation modeling》2013,20(1):23-51

Recent advances in testing mediation have found that certain resampling methods and tests based on the mathematical distribution of 2 normal random variables substantially outperform the traditional z test. However, these studies have primarily focused only on models with a single mediator and 2 component paths. To address this limitation, a simulation was conducted to evaluate these alternative methods in a more complex path model with multiple mediators and indirect paths with 2 and 3 paths. Methods for testing contrasts of 2 effects were evaluated also. The simulation included 1 exogenous independent variable, 3 mediators and 2 outcomes and varied sample size, number of paths in the mediated effects, test used to evaluate effects, effect sizes for each path, and the value of the contrast. Confidence intervals were used to evaluate the power and Type I error rate of each method, and were examined for coverage and bias. The bias-corrected bootstrap had the least biased confidence intervals, greatest power to detect nonzero effects and contrasts, and the most accurate overall Type I error. All tests had less power to detect 3-path effects and more inaccurate Type I error compared to 2-path effects. Confidence intervals were biased for mediated effects, as found in previous studies. Results for contrasts did not vary greatly by test, although resampling approaches had somewhat greater power and might be preferable because of ease of use and flexibility.  相似文献   

Robots Teaching Other Little Robots: Neoliberalism,CCSS, and Teacher Professionalism     

Jason L. Endacott  Ginney P. Wright  Christian Z. Goering  Vicki S. Collet  George S. Denny  Jennifer Jennings Davis 《Review of Education, Pedagogy & Cultural Studies》2013,35(5):414-437

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Relationships Among Cortical Thickness,Reading Skill,and Print Exposure in Adults     

Jason G. Goldman  Frank R. Manis 《Scientific Studies of Reading》2013,17(3):163-176

This study investigated relationships among cortical thickness in the left-hemisphere reading network, and reading skill and experience in adult nonimpaired readers. Given the relationship between print exposure and reading, it is possible that print exposure is related to cortical structure. The pattern of correlations indicated that individuals with higher print exposure had better reading skills and thicker cortices. Furthermore, print exposure accounted for unique variance in cortical thickness in part of the left-hemisphere reading network after accounting for reading skill. This suggests that some of the variation in cortical thickness in adults might be attributable to reading experience, independently of reading skill.  相似文献   

Using the I² Intervention Matrix to Select the Best Course of Action     

Jason Paul Siko 《Performance Improvement》2013,52(10):23-26

The I² intervention selection matrix is a useful tool that will help in the selection of appropriate interventions based on the level of impact and invasiveness of the intervention. It is a two‐axis grid that places interventions in one of four quadrants. Based on which quadrant the intervention falls in, a practitioner can decide which interventions to use, not use, or use with caution. It is a simple yet elegant way to determine appropriateness.  相似文献   

Islands of Detroit: Affect,Nostalgia and Whiteness     

Jason Sperb 《Culture, Theory & Critique》2013,54(2):183-201

Abstract

‘Islands of Detroit’ explores the possibilities for an ‘everyday, oppositional whiteness’, a thoughtful randomness, as a corrective to ‘reactionary’ and ‘evasive’ forms of whiteness which often embed themselves in populist media sites for nostalgia. Drawing on the theoretical work of Svetlana Boym, Uday Singh Mehta and Roland Barthes, this essay looks in particular at a coffee table book, The Way it Was (2004 Bulanda, G., ed. 2004. The Way It Was: Glimpses of Detroit’s History from the Pages of Hour Detroit Magazine, Royal Oak, MI: Momentum.  [Google Scholar]), and its generic sentimentalism, to understand how certain white visual representations of Detroit affectively generate nostalgia, which can in turn conceal pasts and racial tensions. Looking at the history of Detroit (with particular attention on how the two infamous race riots are and are not negotiated), Islands examines visual images of the city – as opposed to the city itself – through the discursive lenses of nostalgia, modernity and affect, while positing that the histories and identities of Detroit remain irreducible to the images which attempt to capture them.  相似文献   

Extended-state-observer-based output feedback adaptive control of hydraulic system with continuous friction compensation     

Chengyang Luo  Jianyong Yao  Jason Gu 《Journal of The Franklin Institute》2019,356(15):8414-8437

This paper presents an extended state observer-based output feedback adaptive controller with a continuous LuGre friction compensation for a hydraulic servo control system. A continuous approximation of the LuGre friction model is employed, which preserves the main physical characteristics of the original model without increasing the complexity of the system stability analysis. By this way, continuous friction compensation is used to eliminate the majority of nonlinear dynamics in hydraulic servo system. Besides, with the development of a new parameter adaption law, the problems of parametric uncertainties are overcome so that more accurate friction compensation is realized. For another, the developed adaption law is driven by tracking errors and observation errors simultaneously. Thus, the burden of extended state observer to solve the remaining uncertainties is alleviated greatly and high gain feedback is avoided, which means better tracking performance and robustness are achieved. The designed controller handles not only matched uncertainties but also unmatched dynamics with requiring little system information, more importantly, it is based on output feedback method, in other words, the synthesized controller only relies on input signal and position output signal of the system, which greatly reduces the effects caused by signal pollution, measurement noise and other unexpected dynamics. Lyapunov-based analysis has proved this strategy presents a prescribed tracking transient performance and final tracking accuracy while obtaining asymptotic tracking performance in the presence of parametric uncertainties only. Finally, comparative experiments are conducted on a hydraulic servo platform to verify the high tracking performance of the proposed control strategy.  相似文献   

Development and reliability of the KIM cycling scale – a measurement tool for the development process to cycling independently     

Jennifer Kavanagh  Kieran Moran  Johann Issartel 《Physical Education & Sport Pedagogy》2020,25(2):174-187

ABSTRACT

Background: Cycling has gained more attention as an important lifelong physical activity. Learning to cycle independently without assistance is a milestone for most children that requires time and practice to master. Cycling was recently added to the motor development model and so a valid and reliable measure of cycling ability is required to allow accurate assessment of the skill. Cycling has many health benefits along with being a commonly reported physical activity globally and therefore is an important skill to promote in early childhood and throughout life. To date, there are no measurement tools examining the developmental process to independent cycling in the early childhood years. The current study aimed to develop and assess the inter-rater and test-retest reliability of the ‘KIM Cycling Scale’.

Methods: Development of the scale occurred in four phases: (1) development of criteria and stages, which used observation of children when learning to cycle and expert panels to develop the initial developmental stages, (2) review of instructions and criteria and pilot inter-rater and test-retest reliability, to ensure that the scale could be used as a standalone scale without requiring further instructions (3) cycling intervention, which allowed assessment of the developmental nature of children along the scale as they learn to cycle independently and to assess typical and alternate routes to independent cycling and (4) inter-rater and test-retest reliability.

Results: Ninety children took part in phase 1, thirty-six children took part in phase 2, seventy-four children took part in phase 3 and one hundred and forty-nine children took part in phase 4. All three hundred and forty-nine children were between 2 and 6 years. The developed scale included eight stages in total. The scale was found to have excellent inter-rater reliability (ICC?=?0.97, 95% CI?=?0.96–0.98) and good to excellent test-retest reliability [(ICC?=?0.91, 95% CI?=?0.87–0.94) & (ICC?=?0.90, 95% CI?=?0.85–0.93)]. Typical routes to independent cycling along the scale were examined and reported as being step-wise on all occasions except one where a two stage jump was as common as the step-wise route. Alternate routes were also reported.

Conclusion: The current study developed a reliable measurement tool for assessing children between 2 and 6 years of age on the developmental process to independent cycling. Having a cycling scale will allow teachers and practitioners to assess competence in cycling and moreover, track changes in skill development. Furthermore, parents could also use the scale to better understand and better asses their child’s progression when learning to cycle.  相似文献   

Contextual factors on physical demands in professional women’s soccer: Female Athletes in Motion study     

Jason D. Vescovi  Olesya Falenchuk 《European Journal of Sport Science》2019,19(2):141-146

The aim of this study was to examine the impact of contextual factors on relative locomotor and metabolic power distances during professional female soccer matches. Twenty-eight players (forwards, n?=?4; midfielders, n?=?12; defenders, n?=?12) that competed in a 90-min home and away match (regular season only). The generalised estimating equations (GEE) was used to evaluate relative locomotor and metabolic power distances for three contextual factors: location (home vs. away), type of turf (natural vs. artificial), and match outcome (win, loss and draw). No differences were observed for home vs. away matches. Moderate-intensity running (20.0?±?1.0?m?min^?1 and 16.4?±?0.9?m?min^?1), high-intensity running (8.6?±?0.4?m?min^?1 and 7.3?±?0.4?m?min^?1) and high-metabolic power (16.3?±?0.5?m?min^?1 and 14.4?±?0.5?m?min^?1) distances were elevated on artificial turf compared to natural grass, respectively. Relative sprint distance was greater during losses compared with draws (4.3?±?0.4?m?min^?1 and 3.4?±?0.3?m?min^?1). Overall physical demands of professional women’s soccer were not impacted by match location. However, the elevation of moderate and high-intensity demands while playing on artificial turf may have implications on match preparations as well as recovery strategies.  相似文献   

Mediating a compromised solidarity     

Jason Vincent A. Cabañes 《Popular Communication》2019,17(2):109-124

ABSTRACT

This article explores popular media as resources for judgment in how settled migrants in Europe imagine solidarities toward newer arrivals seeking entry into the region. It discusses the news and entertainment consumption of Filipino nurses in London and how this figures in their imaginary of social and political bonds with refugees. Drawing on ethnographic interviews, I argue that these Filipino migrants can only articulate a compromised solidarity: one fractured between empathy with refugees and concern about what these newer arrivals might mean for settled migrants in the city. I then explain how the media contribute to this fracturing. One way is that the xenophobia in popular media content on social media leads the Filipinos to assert their difference with other migrants, including refugees. A second is that the Filipinos deploy popular media content, especially on British television, to assert that they belong to UK society more than other migrants, again including refugees.  相似文献   

The history of the unspeakable: Shimokawa Masaharu’s The forgotten history of evacuation     

Jason Morgan 《Inter-Asia Cultural Studies》2018,19(4):644-654

ABSTRACT

Histories of wartime Japan often focus on the Japanese home islands after Japan’s surrender to Allied forces on 15 August 1945. Japanese citizens living in Korea, Manchuria, and elsewhere in the far-flung Japanese Empire are usually left out of the historiographical record. In a new book about the evacuees—hikiagesha—from the defunct Empire, Shimokawa Masaharu presents a vivid, harrowing portrait of the suffering of those who had to make their way back to Japan after the end of the Greater East Asia War. In particular, Shimokawa focuses on Izumi Sei’ichi, who established a sanatorium and abortuary in Fukuoka for women who had been raped by enemy soldiers.  相似文献