On the restricted almost unbiased Liu estimator in the logistic regression model

It is known that when the multicollinearity exists in the logistic regression model, variance of maximum likelihood estimator is unstable. As a remedy, in the context of biased shrinkage Liu estimation, Chang introduced an almost unbiased Liu estimator in the logistic regression model. Making use of his approach, when some prior knowledge in the form of linear restrictions are also available, we introduce a restricted almost unbiased Liu estimator in the logistic regression model. Statistical properties of this newly defined estimator are derived and some comparison results are also provided in the form of theorems. A Monte Carlo simulation study along with a real data example are given to investigate the performance of this estimator.     

An Integrated Methodology for Assessment and Selection of the Project Risk Response Actions

In a systematic process of project risk management, after risk assessment is implemented, the risk analysts encounter the phase of assessment and selection of the project risk response actions (RA). As indicated by many researchers, there are less systematic and well-developed solutions in the area of risk response assessment and selection. The present article introduces a methodology including a modeling approach with the objective of selecting a set of RA that minimizes the undesirable deviation from achieving the project scope. The developed objective function comprises the three key success criteria of a project, namely, time, quality, and cost. Our model integrates overall project management into the project risk response planning (P2RP). Furthermore, the proposed model stresses on an equivalent importance for both "risk" and "response." We believe that applying the proposed model helps the project risk analyst in most effective and efficient manner dealing with his or her complicated RA selection problems. The application of the proposed model was implemented in projects in the construction industry in which it showed tremendous time, cost, and quality improvements.     

«Il n'y a pas d’avenir dans ce métier.» Être chauffeur de VTC en Afrique par temps de pandémie

Si les plateformes ont donné du travail à beaucoup d’Africains, les emplois créés sont de mauvaise qualité, comme la pandémie l'a bien montré. Dans ce contexte, les auteurs examinent la situation particulière des chauffeurs VTC en Afrique en s'appuyant sur des entretiens approfondis, réalisés au Kenya, et sur les méthodes de l'ethnographie virtuelle. Ils montrent que ces travailleurs ont recours à un «régime de débrouille», associant résilience, réajustement et résistance. Pour améliorer les conditions de travail et lutter contre la précarité dans le secteur, il faut à la fois que les pouvoirs publics instaurent des cadres réglementaires et que les travailleurs se mobilisent collectivement.     

Building Financial Knowledge Is Not Enough: Financial Self-Efficacy as a Mediator in the Financial Capability of Low-Income Families

ABSTRACT

Policymakers in many countries have taken an interest in population-level financial capability. Limited empirical work has examined how constructs that makeup financial capability relate and how they function for individuals with low incomes. Using a national sample of low-income Canadians, we investigate relationships between financial knowledge, financial self-efficacy, and savings outcomes. Overall, we find that financial self-efficacy fully mediated the relationship between objective financial knowledge and postsecondary-education saving. The association between objective financial knowledge and retirement saving and emergency saving passed through financial self-efficacy. Efforts to promote financial capability need to focus on more than objective financial knowledge.     

Information content of partially rank-ordered set samples

Partially rank-ordered set (PROS) sampling is a generalization of ranked set sampling in which rankers are not required to fully rank the sampling units in each set, hence having more flexibility to perform the necessary judgemental ranking process. The PROS sampling has a wide range of applications in different fields ranging from environmental and ecological studies to medical research and it has been shown to be superior over ranked set sampling and simple random sampling for estimating the population mean. We study Fisher information content and uncertainty structure of the PROS samples and compare them with those of simple random sample (SRS) and ranked set sample (RSS) counterparts of the same size from the underlying population. We study uncertainty structure in terms of the Shannon entropy, Rényi entropy and Kullback–Leibler (KL) discrimination measures.     

Barriers to green innovation initiatives among manufacturers: the Malaysian case

This study investigated the internal and external barriers to green innovation initiatives among Malaysian manufacturers. Data was gathered through a survey of 153 manufacturing companies in Malaysia. Data was analyzed using the partial least squares technique. Results indicated that the barriers to green products, processes, and systems innovations are different. Issues of environmental resources, attitude and perception, business practices, government support, and customer demand were found to be the barriers to green product innovations, whereas attitude and perception, business practices, poor external partnerships, insufficient information, lack of customer demand, and environmental commercial benefits were determined to be the factors that negatively affect green process innovations. As regards green system innovation, environmental resources, attitude and perception, business practices, technical barriers, government support, and environmental and commercial benefits presented themselves as the internal and external barriers that need to be addressed. The results have important implications for managers of manufacturers that have plans of promoting green products, processes, and system innovations.     

Switching Order Statistics through Random Power Contractions

This paper investigates a new random contraction scheme which complements the length‐biasing and convolution contraction schemes considered in the literature. A random power contraction is used with order statistics, leading to new and elegant characterizations of the power distribution. In view of Rossberg's counter‐example of a non‐exponential law with exponentially distributed spacings of order statistics, possibly the most appealing consequence of the result is a characterization of the exponential distribution via an independent exponential shift of order statistics.     

Risk Assessment for Aflatoxin: III. Modeling the Relative Risk of Hepatocellular Carcinoma

Estimates have been made of the cancer potency of aflatoxin exposure among the U.S. population. Risk modeling is used to assess the dose-response relationship between aflatoxin exposure and primary liver cancer, controlling for hepatitis B virus (HBV), based on data provided by the Yeh et al. study in China. A relative risk model is proposed as a more appropriate alternative to the additive ("absolute" risk) model for transportation of risk coefficients between populations with different baseline rates. Several general relative risk models were examined; the exponential model provided the best fit. The Poisson regression method was used to fit the relative risk model to the grouped data. The effects of exposure to aflatoxin (AFB1) and hepatitis B infection were both found to be statistically significant. The risk of death from liver cancer for those exposed to AFB1 relative to the unexposed population, increases by 0.05% per ng/kg/day exposure of AFB1 (p less than 0.001). The results also indicated a 25-fold increase in the risk of death from liver cancer among those infected with hepatitis B virus, relative to noncarriers (p less than 0.0001). With a hepatitis prevalence rate of 1%, the aflatoxin intake level associated with liver cancer lifetime excess risk of 1 x 10(-5) for the U.S. population was estimated as 253 ng/day, based on a liver cancer baseline rate of 3.4/100,000/yr.     

知识经济与网络对新疆高校体育教育改革的影响

知识经济与网络时代对新疆高校体育教育的影响是巨大的,面对新疆高校体育教育存在的不足,只有进行体育教学改革,提高认识,树立以人为本的教育思想,加强体育教学管理、师资管理与开发,才能适应知识经济与网络的要求.     

Family Change and Continuity in Iran: Birth Control Use Before First Pregnancy

Using data from the 2002 Iran Fertility Transition Survey, we examined birth control use between marriage and first pregnancy. We focused on the post‐1990 increase in birth control use and develop two explanations. The first posits that birth control use reflects a new marriage form, the conjugal marriage, which places a heightened value on the spousal relationship while deemphasizing the centrality of parenthood. A second explanation stresses the use of a new resource, effective birth control, within an Iranian‐Islamist view of marriage. Key to this explanation is the role of the state—Iranian political/religious actors encourage early marriage and the use of birth control. Although the explanations could be complementary, evidence provides more support for the latter.