Approximation of the Bivariate Renewal Function

Recently, Kambo and his co-researchers (2012) proposed a method of approximation for evaluating the one-dimensional renewal function based on the first three moments. Their method is simple and elegant, which gives exact values for well-known distributions. In this article, we propose an analogous method for the evaluation of bivariate renewal function based on the first two moments of the variables and their joint moment. The proposed method yields exact results for certain widely used bivariate distributions like bivariate exponential distribution, bivariate Weibull distributions, and bivariate Pareto distributions. An illustrative example in the form of a two-dimensional warranty problem is considered and comparisons of our method are made with the results of other models.     

Optimal scheduling replacement policies for a system with multiple random works

From the economical viewpoint in reliability theory, this paper addresses a scheduling replacement problem for a single operating system which works at random times for multiple jobs. The system is subject to stochastic failure which results the imperfect maintenance activity based on some random failure mechanism: minimal repair due to type-I (repairable) failure, or corrective replacement due to type-II (non-repairable) failure. Three scheduling models for the system with multiple jobs are considered: a single work, N tandem works, and N parallel works. To control the deterioration process, the preventive replacement is planned to undergo at a scheduling time T or the job's completion time of for each model. The objective is to determine the optimal scheduling parameters (T^* or N^*) that minimizes the mean cost rate function in a finite time horizon for each model. A numerical example is provided to illustrate the proposed analytical model. Because the framework and analysis are general, the proposed models extend several existing results.     

破除中西文化交流的三大思想障碍

在当今全球化的大趋势下倡导和推动中西文化交流有三大思想障碍 ,即认定不可能有平等的文化交流 ,认定未来世界文化的大趋势是一种文化取代另一种文化或认定文化融合的最终境界是无差别的、统一的世界文化 ,夸大不同语言、文化系统的不可译性。在对平等交流有无可能 ,无差别的、统一的世界文化有无可能 ,准确的文化翻译有无可能等三个理论问题作了辨析以后 ,作者表达了一个愿望 :中西双方回到平等交流的元点上来 ,加深了解与认识 ,促进中西文化的进一步交流与融合。     

高T_c超导材料微波特性的自动化测量

采用单腔多模谐振腔,通过部分置换样品的方法,在程控标量网络分析系统上,实现了高 T_c 超导材料微波特性的自动化测量。该方法简单、准确,能同时测出超导样品的工作频率、微波表面阻抗、工作温度等多个参数,并能以图或表的形式给出测试结果。给出了3 cm 频段上YBCO 块材样品在77K 及附近温度下的测量结果,指出 YBCO 块材的微波特性还有待提高。     

国家赔偿责任归责原则之回归

归责原则作为侵权行为类型化的根据,具有统领侵权行为法其他规范的作用。国家公权力侵权行为,虽为一种特殊的侵权行为,但仍属侵权行为法总的归责原则之统辖范围。因此,“违法责任归责原则”的提法在理论上是不成立的,有必要回归到“无过错责任原则”的正确表述上来。这种回归不仅仅是法律术语规范的需要,更为重要的是,它可以引导我们把国家赔偿法的研究重心放在公权行为的违法特性方面。     

Schematic saturated orthogonal arrays obtained by using the contractive replacement method

This paper presents a general method of constructing schematic saturated orthogonal arrays of strength two. We consider a class of mixed saturated orthogonal arrays produced from saturated symmetric orthogonal arrays by using the contractive replacement method, study the Hamming distances of the rows, construct their association schemes, and prove that they are schematic. Some examples are given to illustrate this construction method.     

Effects of testosterone replacement therapy withdrawal and re-treatment in hypogonadal elderly men upon obesity,voiding function and prostate safety parameters

Whether testosterone replacement therapy (TRT) is a lifelong treatment for men with hypogonadism remains unknown. We investigated long-term TRT and TRT withdrawal on obesity and prostate-related parameters. Two hundred and sixty-two hypogonadal patients (mean age 59.5) received testosterone undecanoate in 12-week intervals for a maximum of 11 years. One hundred and forty-seven men had TRT interrupted for a mean of 16.9 months and resumed thereafter (Group A). The remaining 115 patients were treated continuously (Group B). Prostate volume, prostate-specific antigen (PSA), residual voiding volume, bladder wall thickness, C-reactive protein (CRP), aging male symptoms (AMS), International Index of erectile function – erectile function (IIEF-EF) and International Prostate Symptoms Scores (IPSS) were measured over the study period with anthropometric parameters of obesity, including weight, body mass index (BMI) and waist circumference. Prior to interruption, TRT resulted in improvements in residual voiding volume, bladder wall thickness, CRP, AMS, IIEF-EF, IPSS and obesity parameters while PSA and prostate volume increased. TRT interruption reduced total testosterone to hypogonadal levels in Group A and resulted in worsening of obesity parameters, AMS, IPSS, residual voiding volume and bladder wall thickness, IIEF-EF and PSA while CRP and prostate volume were unchanged until treatment resumed whereby these effects were reversed. TRT interruption results in worsening of symptoms. Hypogonadism may require lifelong TRT.     

A fresh approach for intercession of nonresponse in multivariate longitudinal designs

The occurrence of nonresponse is very much plebeian in surveys, which troubles the analysis, and hence, an inappropriate inference is left out. To counterbalance the sour effects of the incompleteness, fresh imputation techniques have been proposed with the aid of multi-auxiliary variates for the estimation of population mean on successive waves. Properties of the proposed estimators have been elaborated, and they have been compared with the work of Priyanka et al. (2015). Detailed simulation study is carried out to substantiate the empirical and theoretical results. Several possible cases have been addressed in which nonresponse can occur.     

The impact of testosterone replacement therapy on glycemic control,vascular function,and components of the metabolic syndrome in obese hypogonadal men with type 2 diabetes

Objective: This study set out to assess effects of testosterone replacement therapy (TRT) on parameters of metabolic syndrome and vascular function in obese hypogonadal males with type 2 diabetes mellitus (DM2).

Study design: Fifty-five obese hypogonadal diabetic males on oral hypoglycemic treatment were enrolled into this one-year, double-blind, randomized, placebo-controlled clinical study. Group T (n?=?28) was treated with testosterone undecanoate (1000?mg i.m. every 10?weeks) while group P (n?=?27) received placebo.

Methods: Anthropometrical and vascular measurements – flow-mediated dilatation (FMD) and intima media thickness (IMT) – biochemical and hormonal blood sample analyses were performed at the start of the study and after one year. Derived parameters (BMI, HOMA-IR, calculated free testosterone (cFT) and bioavailable testosterone (BT)) were calculated.

Results: TRT resulted in reduction of HOMA-IR by 4.64?±?4.25 (p?p?p?=?.005).

Conclusion: TRT normalized serum testosterone levels, improved glycemic control and endothelial function while exerting no ill effects on the study population.     

Placement characteristics and stability: a longitudinal analysis of Norwegian children in foster homes

This paper investigates how enhanced support for foster parents, such as covering fees and providing consultants and relief, may reduce the number of replacements experienced by children in foster care. It also investigates the extent to which replacements are associated with family (kin) vs. non‐family foster parents, or with legal characteristics of the placement (i.e. forced administrative decisions vs. relief measures agreed upon by the parents). Statistical analyses of administrative data from Norway investigated the longitudinal relationships between these characteristics and the number of replacements at two levels – children (N = 16 109) and municipalities (N = 418) – over 5 years (2007–2011). The results reveal modest associations between enhanced support and fewer replacements; for example, replacement rates are lower for children placed in homes of kin than in non‐family homes. Replacements also tend to be fewer when the placement is forced rather than consensual.