Convolution power kernels for density estimation

We propose a new type of non-parametric density estimators fitted to random variables with lower or upper-bounded support. To illustrate the method, we focus on nonnegative random variables. The estimators are constructed using kernels which are densities of empirical means of m i.i.d. nonnegative random variables with expectation 1. The exponent m   plays the role of the bandwidth. We study the pointwise mean square error and propose a pointwise adaptive estimator. The risk of the adaptive estimator satisfies an almost oracle inequality. A noteworthy result is that the adaptive rate is in correspondence with the smoothness properties of the unknown density as a function on (0,+∞)$(0,+\infty )$. The adaptive estimators are illustrated on simulated data. We compare our approach with the classical kernel estimators.     

Local asymptotic minimax theory for block-decreasing densities

In this paper, we study Lebesgue densities on (0,∞)^d$(0,\infty {)}^d$ that are non-increasing in each coordinate, while keeping all other coordinates fixed, from the perspective of local asymptotic minimax lower bound theory. In particular, we establish a local optimal rate of convergence of the order n^−1/(d+2)$n^{-1/(d+2)}$.     

Addition of runs to an s-level supersaturated design

The purpose of the present work is to extend the work of Gupta et al. (2010) to s  -level column balanced supersaturated designs. Addition of runs to an existing E(χ²)-optimal$E({\chi }^2)\mathrm{-}\mathrm{optimal}$ supersaturated design and to study the optimality of the resulting design is an important issue. This paper considers the study of the optimality of the resulting design. A lower bound to E(χ²)$E({\chi }^2)$ has been obtained for the extended supersaturated designs. Some examples and a small catalogue of E(χ²)-optimal$E({\chi }^2)\mathrm{-}\mathrm{optimal}$ supersaturated designs are also presented.     

优化营商环境与行政审批制度改革研究

优化营商环境的重要进展,与放管服改革的逐步深入推进紧密关联。简政放权、放管结合、优化服务,都包含着优化营商环境的重要举措和内容,世界银行对营商环境的评估指标中多数也与行政审批有关。我国优化营商环境在多维度取得了转折性进展,从行政审批制度改革着手优化营商环境积累了重要实践经验。按照中央“十四五”规划建议中提出的“有为政府”要求和高质量发展目标,行政审批和后续监管领域仍然存在的问题需要解决。为持续优化营商环境,今后行政审批制度改革要从注重数量变化向结构优化改革转变,同时在放管结合上着力并有所突破。     

第十届中国戏剧节新创剧目简论

第十届中国戏剧节上展演的新创剧目在题材上有向政治剧和底层生活剧集中的趋势。政治剧都以历史剧的形式出现,多表现凶险的政治强力和善良人性及人类基本正面价值之间的悲剧性冲突;底层生活剧则都在当前的时空中表现社会、经济、精神资源严重匮乏的下层人民的生活实况。剧作家对这两大题材的开掘和表现在思想上超越了以往的深度,在艺术上具有更强烈的情感冲击力。它们标志了新世纪以来戏剧创作基本的取材方向和艺术水平。     

高低分学生英语学习策略的对比研究

本研究结合问卷调查与个案访谈,比较非英语专业英语高分者和低分者的学习策略差异。研究结果表明：高分组学生对元认知策略和认知策略的使用频率显著高于低分组,而低分组学生对补偿策略的使用频率显著高于高分组;两组学生对记忆策略、情感策略和社交策略的使用频率无显著性差异,其中对社交策略两组学生均最少使用。以上结论启示我们：在英语学习中,应当注意学习策略的适当训练和合理使用,并更加重视元认知策略和社交策略的应用。     

Reliability analysis for stress-strength model from a general family of truncated distributions under censored data

Abstract

Under progressive Type-II censoring, inference of stress-strength reliability (SSR) is studied for a general family of lower truncated distributions. When the lifetime models of the strength and stress variables have arbitrary and common parameters, maximum likelihood and pivotal quantities based generalized estimators of SSR are established, respectively. Confidence intervals are constructed based on generalized pivotal quantities and bootstrap technique under different parameter cases as well. In addition, to compare the equivalence of the strength and stress parameters, likelihood ratio testing of interested parameters is provided as a complementary. Simulation studies and two real-life data examples are provided to investigate the performance of proposed methods.     

Simultaneous selection of extreme populations:a bayesian approach

The problem of simultaneously selecting two non-empty subsets, S_Land S_U, of k populations which contain the lower extreme population (LEP) and the upper extreme population (UEP), respectively, is considered. Unknown parameters θ₁,…,θ_kcharacterize the populations π₁,…,π_kand the populations associated with θ_[1]=min θ_i. and θ_[k]= max θ_i. are called the LEP and the UEP, respectively. It is assumed that the underlying distributions possess the monotone likelihood ratio property and that the prior distribution of θ= (θ₁,…,θ_k) is exchangeable. The Bayes rule with respect to a general loss function is obtained. Bayes rule with respect to a semi-additive and non-negative loss function is also determined and it is shown that it is minimax and admissible. When the selected subsets are required to be disjoint, it shown that the Bayes rule with respect to a specific loss function can be obtained by comparing certain computable integrals, Application to normal distributions with unknown means θ₁,…,θ_kand a common known variance is also considered.     

Efficacy of newer medications for lower urinary tract symptoms attributed to benign prostatic hyperplasia: a systematic review

We conducted a systematic review to evaluate the efficacy and adverse effects of newer drugs used to treat lower urinary tract symptoms (LUTS). The drugs were either Food and Drug Administration (FDA) approved for benign prostatic hyperplasia (BPH) or not FDA approved for BPH but have been evaluated for treatment of BPH since 2008. We searched bibliographic databases through September 2017. We included randomized controlled trials (RCTs) lasting one month or longer published in English. Outcomes of interest were LUTS assessed by validated measures. Efficacy was interpreted using established thresholds indicating clinical significance that identified the minimal detectable difference. Twenty-three unique, generally short-term, RCTs evaluating over 9000 participants were identified. Alpha-blocker silodosin and phosphodiesterase type 5 inhibitor tadalafil were more effective than placebo in improving LUTS (moderate strength evidence) but these drugs had more adverse effects, including abnormal ejaculation (silodosin). Anticholinergics were only effective versus placebo when combined with an alpha-blocker. Evidence was generally low strength or insufficient for other drugs. Evidence was insufficient to assess long-term efficacy, prevention of symptom progression, need for surgical intervention, or long-term adverse effects. Longer trials are needed to assess the effect of these therapies on response rates using established minimal detectable difference thresholds, disease progression, and harms.