305 research outputs found
Patterns of Retirement as Reflected in Income Tax Records for Older Workers
No full textIf retirement means a substantial and sustained reduction in the time spent working for pay or profit, measurement requires a definition of substantial and sufficient observations of the same individuals to determine whether a transition from “working” to “retired” status has occurred. Using the Statistics Canada Longitudinal Administrative Databank, a 20 percent sample of the individual income tax returns of all tax filers since 1980, we identify those with significant labour force attachment at ages 50-52, and follow them year by year. If retired means having no income from employment, the median age of retirement is about 63 for men, 62 for women. That is true for all cohorts. If earning up to half of one’s previous employment income is deemed consistent with being retired, the median age is about 60 for both men and women. Results obtained in this way are consistent with calculations based on Labour Force Survey data.retirement, older workers
About the Ash Lad
No full textAbout the Ash Lad is inspired by a Dano-Norwegian folktale collection by Peter Christen Asbjørnsen and Jørgen Moe that was published in 1859. It is said that Henrik Ibsen, author of the original Peer Gynt drama, was inspired by this collection of folk tales of which the story “About Ash Lad , Who Stole the Troll’s Silver Ducks, Coverlet, and Golden Harp” (some other titles it is known by include “Boots and the Troll”), is a part of. In this piece, the unfolding of the story in the form of a suite is also inspired by the famous Grieg setting of Peer Gynt, as we follow the hero along his journey, through perils and triumphs.
There are a total of nine small movements, all connected by a dance-like ‘Passage’ theme, that parallel the Ash Lad’s story as he ‘borrows’ three items from a Troll in order to win the local princesses hand in marriage and a decent half of the kingdom on top of that.
It was an absolute joy to compose this work for the thoroughly amazing Inventi Ensemble, and I thank them for the opportunity to transport myself creatively into a world of fantasy and imagine my own sounds within this old Dano-Norwegian realm.
Work Details
Duration: 10 minutes
Composed: 2020
Commissioned by: Inventi Ensemble (Melissa Doecke and Ben Opie)</p
Empirical likelihood for LAD estimators in infinite variance ARMA models
No full textIn this paper, we use an empirical likelihood method to construct confidence regions for the stationary ARMA(p, q) models with infinite variance. An empirical log-likelihood ratio is derived by the estimating equation of the self-weighted LAD estimator. It is proved that the proposed statistic has an asymptotic standard chi-squared distribution. Simulation studies show that in a small sample case, the performance of empirical likelihood method is better than that of normal approximation of the LAD estimator in terms of the coverage accuracy. (C) 2010 Elsevier B.V. All rights reserved.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000287109500007&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Statistics & ProbabilitySCI(E)1ARTICLE2212-2198
Reflective Healthcare Systems: Micro-Cycle of Self-Reflection to empower users
No full textData collection and reflection are considered an integrated process in Personal Informatics to help users take action towards changing behaviour. Facilitating the collection and visualization of large data sets has been a major technical challenge to guarantee meaningful and effortless information to users. However this focus results in a passive involvement of users in these stages, creating distance between the user and their data, thus hindering proper understanding of people’s current behaviours. Designing for active participation may aid users in forming a closer bond to data. Going beyond the support of visualization of performance data, this paper introduces ESTHER 1.3 as an approach to facilitate active mini cycles of self-reflection (mCR) by means of in-situ self-reporting mechanisms. ESTHER 1.3 is presented as an implementation of this mini cycles in the context of physical activity and knowledge workers. A field study evaluation of 23 days with 5 users shows the opportunities of the mini cycles to engage people in deeper reflection and to support them to perform better-informed actions, as well as the challenges in the implementation of mCR elements for a specific context.Industrial DesignIndustrial Design Engineerin
Estimation and tests for power-transformed and threshold GARCH models
No full textConsider a class of power transformed and threshold GARCH(p,q) (PTTGRACH(p,q)) model, which is a natural generalization of power-transformed and threshold GARCH(1,1) model in Hwang and Basawa (2004) and includes the standard GARCH model and many other models as special cases. We ¯rst establish the asymptotic normality for quasi-maximum likelihood estimators (QMLE) of the parameters under the condition that the error distribution has ¯nite fourth moment. For the case of heavy-tailed errors, we propose a least absolute deviations estimation (LADE) for PTTGARCH(p,q) model, and prove that the LADE is asymptotically normally distributed under very weak moment conditions. This paves the way for a statistical inference based on asymptotic normality for heavy-tailed PTTGARCH(p,q) models. As a consequence, we can construct the Wald test for GARCH structure and discuss the order selection problem in heavy-tailed cases. Numerical results show that LADE is more accurate than QMLE for heavy tailed errors. Furthermore the theory is applied to the daily returns of the Hong Kong Hang Seng Index, which suggests that asymmetry and nonlinearity could be present in the ¯nancial time series and the PTTGARCH model is capable of capturing these characteristics. As for the probabilistic structure of PTTGARCH(p,q), we give in the appendix a necessary and su±cient condition for the existence of a strictly stationary solution of the model, the existence of the moments and the tail behavior of the strictly stationary solution
FOURIER TRANSFORM INFRARED EMISSION SPECTROSCOPY OF LaH AND LaD
No full textAuthor Institution: University of Arizona, Tucson, AZ 85721.; University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.The electronic emission spectra of LaH and LaD were investigated in the 750 nm to spectral region using a Fourier transform spectrometer. The bands were excited in a lanthanum hollow cathode lamp in the presence of a mixture of neon and or . The observed bands have been classified into two electronic transitions. and (following the notation for YH in J. Chem. Phys. 101, 9283-9288 (1994). The laH bands observed in the region with Q-heads at and have been assigned as the 0-0 and 1-1 bands of the transition. To higher wavenumbers a group of bands observed in the region have been assigned into and sub-bands of a new electronic transition . The rotational analysis of the 0-0 and 1-1 bands of each transition has been carried out and the equilibrium constants for the ground and excited states have been obtained
Why liberalization alone has not improved agricultural productivity in Zambia : the role of asset ownership and working capital constraints
No full textThe authors use a large panel data set from Zambia to examine factors that could explain the relatively lackluster performance of the country's agricultural sector after liberalization. Zambia's liberalization significantly opened the economy but failed to alter the structure of productionor help realize efficiency gains. They reach two main conclusions. First, not owning productive assets (in Zambia, draft animals and implements) limits improvements in agricultural productivity and household welfare. Owning oxen increases income directly, allows farmers to till their fields efficiently when rain is delayed, increases the area cultivated, and improves access to credit and fertilizer markets. Second, the authors reject the hypothesis that the application of fertilizer is unprofitable because of high input prices. Rather, fertilizer use appears to have declined because of constraints on supplies, which government intervention exacerbated instead of alleviating. (Extending the use of fertilizer to the many producers not currently using it would be profitable, but increasing the amount applied by the few producers who now have access to it would not be.) Policies to foster accumulation of the assets needed for agricultural production (including draft animals and implements) and to provide complementary public goods (education, credit, and good agricultural extension services) could greatly help reduce poverty and improve productivity.Economic Theory&Research,Environmental Economics&Policies,Labor Policies,Banks&Banking Reform,Agricultural Knowledge&Information Systems,Environmental Economics&Policies,Economic Theory&Research,Banks&Banking Reform,Agricultural Knowledge&Information Systems,Agricultural Research
Optimization in logical analysis of data
No full textLogical Analysis of Data (LAD) is a machine learning/data mining methodology that combines ideas from areas such as Boolean functions, optimization and logic. In this thesis, we focus on the description and the application of novel optimization models to the construction of improved and/or simplified LAD models of data. We address the construction of LAD classification models, proposing two alternative ways of generating patterns, or rules. First, we show how to construct LAD models based on patterns of maximum coverage. We show, through a series of computational experiments, that such models are as good as, if not better than those obtained with the standard LAD implementation and other machine learning methods, while requiring a much simpler calibration for optimal performance. We formulate the problem of finding the most suitable LAD model as a large linear program, and show how to solve it using column generation. For the subproblem phase, we describe a branch-and-bound algorithm, whose performance is significantly superior to that of a commercial integer programming solver. The
LAD models produced by this algorithm are virtually parameter-free and practically as accurate as the calibrated models obtained with other machine learning methods. Finally, we propose a novel regression algorithm that extends the LAD methodology for the case of a numerical outcome and show that it constitutes an attractive alternative to other regression methods in terms of performance and flexibility of use.Ph.D.Includes bibliographical references (p. 95-103)
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