Search results for "Variable"
showing 10 items of 1674 documents
Estimation of linear errors-in-variable models with error free covariates: a backfitting approach
2008
We present a backfitting algorithm to estimate linear regression mod- els having both error-prone and error-free covariates as predictors. The algorithm assumes that the variance-ratios are known, and it is particulary efficient when several explanatory variables are included. The resulting estimators are shown to be unbiased and to perform well as compared to method-of-moments estimators which are usually employed when the variance ratio is known.
Implicit regulation for automotive variators
2001
A well-known practice uses mechanical variators to realize the so-called continuously variable transmissions (CVTs) for automotive application. A remarkable problem for one of the most used CVTs is given by the hydraulic control of the axial thrust on the half-pulleys that is necessary for torque transmission. It involves a heavy decrease in transmission efficiency. In the present paper, the possible production of the required axial thrust by a simple spring to eliminate hydraulic losses is analysed. It is shown that the power capacity of such a regulated variator is near to the maximum possible, and the belt torque loss is always considerably lower than the sum of the belt and pump losses…
Best Friends Forever? Modeling the Mechanisms of Friendship Network Formation
2020
The formation of friendships and alliances is a ubiquitous feature of human life, and likely a crucial component of the cooperative hunting and child-rearing practices that helped our early hominin ancestors survive. Research on contemporary human beings typically finds that strong-tie social networks are fairly small, and reveals a high degree of physical (e.g., age) and social-structural (e.g., educational attainment) homophily. Yet, existing work all too often underestimates, or even ignores, the importance of abstract, symbolic homophily (such as shared identities or worldviews) as a driver of friendship formation. Here we employ agent-based modeling to identify the optimal variable wei…
Best friends in adolescence show similar educational careers in early adulthood
2012
The present study investigated the role of best friends in educational career development from adolescence to adulthood. Participants' (N = 476) reciprocal best friendships were identified at age 15, while their educational attainment was investigated in early adulthood (age 26), their intelligence (IQ) at age 13, and parental education, educational expectations and academic achievement at age 16. The results revealed that adolescent best friends ended up pursuing similar educational careers in adulthood. Furthermore, three kinds of partner-effects were found when adolescents' prior career behaviors were controlled for: (1) best friends' intelligence predicted adolescents' later academic pe…
Parenting Dimensions and Internalizing Difficulties in Italian and U.S. Emerging Adults: The Intervening Role of Autonomy and Relatedness
2015
The present study examined the associations between emerging adults’ perceived parental psychological control and autonomy support, and their autonomy, relatedness and internalizing difficulties in Italy and the U.S. The participants included 494 Italian and 414 U.S. college students, between 18 and 28 years of age (Mean = 21.58, SD = 2.18). Our findings showed that dependency-oriented psychological control had no significant direct associations with autonomy, relatedness or internalizing difficulties. Moreover, the association between parental autonomy support and internalizing problems was fully intervened by autonomy and relatedness, whereas the association between achievement-oriented p…
Unawareness, Priors and Posteriors
2008
Abstract. This note contains first thoughts on awareness of unawareness in a simple dynamic context where a decision situation is repeated over time. The main consequence of increasing awareness is that the model the decision maker uses, and the prior which it contains, becomes richer over time. The decision maker is prepared to this change, and we show that if a projection-consistency axiom is satisfied unawareness does not affect the value of her estimate of a payoff-relevant conditional probability (although it may weaken confidence in such estimate). Probability-zero events however pose a challenge to this axiom, and if that fails, even estimate values will be different if the decision …
Mood, Burnout, and Dispositional Optimism in Kayak Polo Players During Their Competitive Stage.
2021
© 2021. This manuscript version is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by/4.0/ This document is the Accepted Manuscript version of a Published Work that appeared in final form in Frontiers in Psychology. To access the final edited and published work see 10.3389/fpsyg.2021.667603 The main objective of performance sport is to obtain achievements at the highest level through the adequate development of the athlete. The scientific literature demonstrates the fundamental role played by the inclusion of certain psychological variables in the training plan. This study examined the psychological profile of kayak polo players through the variables of burnou…
Using Factor Analysis in Relationship Marketing
2013
Abstract The purpose of the paper is to present a detailed application of the factor analysis technique within the domain of relationship marketing. A comprehensive literature review is undertaken regarding the concept of customer loyalty – an important variable of relationship marketing. Loyalty is defined by its two dimensions – behavioral and attitudinal; the second dimension is understood through the three components of the human psyche: affective, cognitive and conative. Conative Loyalty is measured through four items which are statistically and semantically reduced to two items without a heavy loss of information.
Principled animation design improves comprehension of complex dynamics
2016
International audience; Learners can have difficulty in decomposing conventionally designed animations to obtain raw material suitable for building high quality mental models. A composition approach to designing animations based on the Animation Processing Model was developed as a principled alternative to prevailing approaches. Outcomes from studying novel and conventional animation designs (independent variable) were compared with respect to mental model quality, knowledge of local kinematics, and capacity to transfer (dependent variables). Study of a compositional animation that presented material in a contiguous fashion resulted in higher quality mental models of a piano mechanism than …
Islands of vulnerability and resilience: Manufactured stereotypes?
2018
This paper interrogates the aspects of islandness labelled ‘vulnerability’ and ‘resilience’ through analysing the concepts’ definitions from a development perspective. The investigation is conducted through the lens of four assumed islandness aspects: boundedness, smallness, isolation, and littorality. Discussion examines how and why core concepts of vulnerability and resilience have emerged from island studies, demonstrating how these two aspects of islandness are socially and culturally constructed, can influence development approaches taken, and are enhanced by island geographies. Drawing on insights from island geographies around the world, while comparing island and non-island perspect…