A new two-parameter lifetime distribution with decreasing,increasing or upside-down bathtub-shaped failure rate

In this paper, we introduce a generalization of the Bilal distribution, where a new two-parameter distribution is presented. We show that its failure rate function can be upside-down bathtub shaped. The failure rate can also be decreasing or increasing. A comprehensive mathematical treatment of the new distribution is provided. The estimation by maximum likelihood is discussed, and a closed-form expression for Fisher’s information matrix is obtained. Asymptotic interval estimators for both of the two unknown parameters are also given. A simulation study is conducted and applications to real data sets are presented.     

Zen and the art of aut-ethnography: a tribute to Robert M. Pirsig

With the passing of Robert M. Pirsig, I felt that it was an appropriate time to write a tribute to his work and the influence it has had on my own theorising in regard to autistic ways of being. This reflection utilises the concept of an ‘aut-ethnography’ to examine passages that I had highlighted word by word when I first read Pirsig’s book: Zen and the Art of Motorcycle Maintenance. These fragments contain links to a number of theoretical ‘lines of flight’ within my own work and that of others, from his concepts of dynamic ‘quality’ to his discussion on the tension between scientific method and lived experience.     

From Codes to Contextual Collaborations: Shifting the Thinking About Ethics in Social Work

In this article, the authors argue that the current emphases in social work on codes, standards, and decision-making models are insufficient to the task of ensuring ethical relationships between workers and clients. Three fundamental assumptions that underpin codes and standards are analyzed. The authors then explore the nature of ethical relationships and demonstrate how codes and standards, in their current form, do not address the complexity and contextuality of the social work relationship. After considering why the profession relies so heavily on codes and standards, they call for a re-thinking of ethical relationships, offering ideas and recommendations for those relationships.     

Confidence distributions applied to propagating uncertainty to inference based on estimating the local false discovery rate: A fiducial continuum from confidence sets to empirical Bayes set estimates as the number of comparisons increases

Empirical Bayes estimates of the local false discovery rate can reflect uncertainty about the estimated prior by supplementing their Bayesian posterior probabilities with confidence levels as posterior probabilities. This use of coherent fiducial inference with hierarchical models generates set estimators that propagate uncertainty to varying degrees. Some of the set estimates approach estimates from plug-in empirical Bayes methods for high numbers of comparisons and can come close to the usual confidence sets given a sufficiently low number of comparisons.     

The almost sure convergence rate of the estimator of optimized certainty equivalent risk measure under α-mixing sequences

Conditional value-at-risk (CVaR) model is a kind of financial risk measure that is extensively supported and accepted by international financial community. Its optimized form can be regarded as an optimized certainty equivalent (OCE) risk measurement. In this paper, we mainly discuss and analyze the strong laws of large numbers and the convergence rate of OCE's estimator under α-mixing sequences. The result shows that the almost sure convergence rate of CVaR estimator is given by the results of OCE estimator. Its convergence rate is inversely proportional to the square root of the sample size under certain conditions. Its effectiveness is verified by simulation experiments for two classical α-mixing sequences.     

An improved two-stage procedure to compare hazard curves

Qiu and Sheng has proposed a powerful and robust two-stage procedure to compare two hazard rate functions. In this paper we improve their method by using the Fisher test to combine the asymptotically independent p-values obtained from the two stages of their procedure. In addition, we extend the procedure to situations with multiple hazard rate functions. Our comprehensive simulation study shows that the proposed method has a good performance in terms of controlling the type I error rate and of detecting power. Three real data applications are considered for illustrating the use of the new method.     

Limit Theorems for Semi-Markov Queues and Their Applications

We begin by definition of semi-Markov flow and discussion of its properties. Asymptotic behavior of multi-server and single-server queueing systems is studied under assumption of time-compression or service time growth. The results obtained are used for calculation of large systems reliability. Statistical estimates of parameters involved are also provided.     

Daily Inhalation Rate and Time‐Activity/Location Pattern in Japanese Preschool Children

Lack of data on daily inhalation rate and activity of children has been an issue in health risk assessment of air pollutants. This study aimed to obtain the daily inhalation rate and intensity and frequency of physical activity in relation to the environment in Japanese preschool children. Children aged four–six years (n= 138) in the suburbs of Tokyo participated in this study, which involved three days' continuous monitoring of physical activity using a tri‐axial accelerometer and parent's completion of a time/location diary during daily life. The estimated three‐day mean daily inhalation rate (body temperature, pressure, saturated with water vapor) was 9.9 ± 1.6 m³/day (0.52 ± 0.09 m³/kg/day). The current daily inhalation rate value of 0.580 m³/kg/day proposed for use in health risk assessment in Japan is confirmed to be valid to calculate central value of inhaled dose of air pollutants in five‐ to six‐year‐old children. However, the 95th percentile daily inhalation rate of 0.83 m³/kg/day based on measurement for five‐year‐old children is recommended to be used to provide an upper bound estimate of exposure that ensure the protection of all five‐ to six‐year‐old children from the health risk of air pollutants. Children spent the majority of their time in sedentary and light level of physical activity (LPA) when indoors, while 85% of their time when outdoors was spent in LPA and moderate‐to‐vigorous physical activity. The results suggest the need to consider variability of minute respiratory ventilation rate according to the environment for more refined short‐term health risk assessment.     

哈贝马斯批判理论的修辞性研究

哈贝马斯(Habermas)是当代西方具有影响力的批判理论家,其对修辞学的贡献在于将归属于批判理论的交往重要性进行理论化。他对各种形式的公共性的历史叙述,尤其是18世纪的公共领域的叙述,以及他对交往行为理论的阐述,构成了他对20世纪修辞学理论所作的贡献。本文拟从修辞学的角度探讨哈贝马斯的批判理论,以便从一个全新的视角对他的理论进行解读。     

低压及欠平衡钻井中注气量对井内压力的影响

以多相瞬变流理论为基础,建立了井筒内气液两相流动模型,并对低压欠平衡钻井中注气量对井内压力的影响关系和规律进行计算和分析。计算分析结果表明,注气量对井内压力的影响除与注气量本身大小有关外,还与井深、井眼与钻柱结构尺寸、井内液相流量和性质等因素密切相关。单纯增大注气量并不一定就必然会导致井内压力的降低,这取决于所给条件下构成井筒内气液两相流体的静液压力和流阻间的平衡关系。介绍的模型及方法对确定低压欠平衡钻井过程中各相关参数、地面压缩机组的配置、以及设计方案等有一定指导意义。