Prediction of mechanical property of steel strips using multivariate adaptive regression splines

In recent times, the problem of prediction of properties of a steel strip has attracted enormous attention from different communities such as statistics, data mining, soft computing, and engineering. This is due to the prospective benefits of reduction in testing and inventory cost, increase in yield, and improvement in delivery compliance. The complexity of the problem arises due to its dependency on the chemical composition of the steel, and a number of processing parameters. To predict the mechanical properties of the strip (yield strength, ultimate tensile strength, and Elongation), a model based on multivariate adaptive regression spline has been developed. It is found that the prediction agrees well with the actual measured data.     

M-estimators of some GARCH-type models; computation and application

In this paper, we consider robust M-estimation of time series models with both symmetric and asymmetric forms of heteroscedasticity related to the GARCH and GJR models. The class of estimators includes least absolute deviation (LAD), Huber’s, Cauchy and B-estimator as well as the well-known quasi maximum likelihood estimator (QMLE). Extensive simulations are used to check the relative performance of these estimators in both models and the weighted resampling methods are used to approximate the sampling distribution of M-estimators. Our study indicates that there are estimators that can perform better than QMLE and even outperform robust estimator such as LAD when the error distribution is heavy-tailed. These estimators are also applied to real data sets.     

Accountability and value for money: a theoretical framework for the relationship in public–private partnerships

There is an implicit assumption in the UK Treasury’s publications on public-private partnerships (PPP)—also more commonly known in the United Kingdom as private finance initiative (PFI)—that accountability and value for money (VFM) are related concepts. While recent academic studies on PPP/PFI (from now on as PFI) have focused on VFM, there is a notable absence of studies exploring the ‘presumed’ relationships between accountability and VFM. Drawing on Dubnick’s (Dubnick and Romzek in American public administration, politics and the management of expectations. Macmillan, New York, 1991, Research in public administration. JAI, Greenwich, 1993; Dubnick in Public service ethics and the cultures of blame, 1996, Public sector ethics: finding and implementing values. Routledge, London, 1998, Int J Org Theory Behav 6(3):405–441, 2003, Public Perform Manage Rev 28(3):376–417, 2005; Dubnick and Justice in But can you trust them to be ethical, 2002) framework for accountability and PFI literature, we develop a research framework for exploring potential relationships between accountability and VFM in PFI projects by proposing alternative accountability cultures, processes and mechanisms for PFI. The PFI accountability model is then exposed to four criteria—warrantability, tractability, measurability and feasibility. Our preliminary interviews provide us guidance in identifying some of the cultures, processes and mechanisms indicated in our model which should enable future researchers to test not only the UK Government’s claimed relationships between accountability and VFM using more specific PFI empirical data, but also a potential relationship between accountability and performance in general.     

A study of subjective visual disturbances in jewellery manufacturing

Subjective Visual Disturbances are silent adversaries that appear over a period of continued exposure and arise when the visual demands of the tasks exceed the visual abilities of the user. Jewellery manufacturing activity involves precision designs, setting the metal and stones, polishing and filing which requires higher visual demand. Therefore, it is expected that the jewellery manufacturing workers may experience subjective visual disturbances. This study was taken up with the following objectives 1) To study the presence of subjective visual disturbances among jewellery manufacturing workers and compare the same with VDT operators 2) To study the effect of work exposures on subjective visual disturbances and 3) to ascertain whether subjective visual disturbances have any permanent vision related problems. The study was carried out on jewellery manufacturing workers, VDT operators and on graduate students. The symptoms of subjective visual disturbances were identified using a questionnaire developed by Sheedy (2003). Viewing distances were measured and visual angles were calculated. The eye check--ups were also carried out. The subjective visual disturbances were higher in jewellery manufacturing workers. The findings suggest that work exposure has an impact on the causation of subjective visual disturbances. No pathological conditions of the eyes were observed.     

Description and Propagation of Uncertainty in Input Parameters in Environmental Fate Models

Today, chemical risk and safety assessments rely heavily on the estimation of environmental fate by models. The key compound‐related properties in such models describe partitioning and reactivity. Uncertainty in determining these properties can be separated into random and systematic (incompleteness) components, requiring different types of representation. Here, we evaluate two approaches that are suitable to treat also systematic errors, fuzzy arithmetic, and probability bounds analysis. When a best estimate (mode) and a range can be computed for an input parameter, then it is possible to characterize the uncertainty with a triangular fuzzy number (possibility distribution) or a corresponding probability box bound by two uniform distributions. We use a five‐compartment Level I fugacity model and reported empirical data from the literature for three well‐known environmental pollutants (benzene, pyrene, and DDT) as illustrative cases for this evaluation. Propagation of uncertainty by discrete probability calculus or interval arithmetic can be done at a low computational cost and gives maximum flexibility in applying different approaches. Our evaluation suggests that the difference between fuzzy arithmetic and probability bounds analysis is small, at least for this specific case. The fuzzy arithmetic approach can, however, be regarded as less conservative than probability bounds analysis if the assumption of independence is removed. Both approaches are sensitive to repeated parameters that may inflate the uncertainty estimate. Uncertainty described by probability boxes was therefore also propagated through the model by Monte Carlo simulation to show how this problem can be avoided.     

The Impact of in-Service Training and Motivation on Job Performance of Technical & Vocational Education Teachers: Role of Person-Job Fit

In-service education and training (INSET), motivation and person-job fit of workers are considered vital for the performance of employees. The focused purpose of the study is to examine the associations between in-service training and motivation impact on job performance of Technical Vocational Education and Training (TVET) teachers, while examining the moderating role of person-job fit. Using convenience sampling technique, data is collected from TVET teachers in South Asia. The finding of this study revealed a significant impact for in-service training and motivation on job performance. This research study is useful for the HR managers and practitioners to utilize their employee’s true potential to get the desired results.

     

Circular Strongly Balanced Repeated Measurements Designs

Magda (1980 Magda , C. G. ( 1980 ). Circular balanced repeated measurements designs . Commun. Statist. Theor. Meth. 9 : 1901 – 1918 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) and Hedayat (1981 Hedayat , A. S. ( 1981 ). Repeated measurements designs-IV: recent advances (with discussion) . Bull. Int. Statist. Inst. 1 : 591 – 610 . [Google Scholar]) first considered the construction of circular strongly balanced repeated measurements designs. Sen and Mukerjee (1987 Sen , M. , Mukerjee , R. ( 1987 ). Optimal repeated measurements designs under interaction . J. Statist. Plann. Infer. 17 : 81 – 91 .[Crossref], [Web of Science ®] , [Google Scholar]) and Roy (1988 Roy , B. K. ( 1988 ). Construction of strongly balanced uniform repeated measurements designs . J. Statist. Plann. Infer. 19 : 341 – 348 .[Crossref], [Web of Science ®] , [Google Scholar]) considered the optimality and existence of circular strongly balanced repeated measurements designs based on the method of differences and Hamiltonian decomposition of lexicographic product of two graphs. In this article, we consider the construction of circular strongly balanced repeated measurements designs using the newly proposed method called cyclic shifts, and propose some new designs for p < v.     

New Estimates and Projections of Population Growth in Pakistan

Pakistan's population growth rate rose steadily from about 2.6 percent per annum in the early 1960s to a high of about 3.5 percent during the late 1980s. Since then it has declined to an estimated 2.1 percent for 2003. Growth rates calculated from the population censuses, which show a very different picture, are distorted by differential accuracy of enumeration. During the period of rising growth rates, fertility was constant at just under 7 children per woman while life expectancy at birth rose by nearly 20 years. Fertility decline began in the late 1980s, bringing the population growth rate down with it. Remarkably, there appears to have been little change in life expectancy over the past 15 years.     

发展中加贸易的障碍--倾销与反倾销问题

倾销与反倾销摩擦已成为中国、加拿大贸易中的一个障碍。本文分析了摩擦产生的多方面原因 ,提出了解决问题的若干思路。