Comparison of computer programs for simple linear L 1 regression

A number of efficient computer codes are available for the simple linear L ₁ regression problem. However, a number of these codes can be made more efficient by utilizing the least squares solution. In fact, a couple of available computer programs already do so.

We report the results of a computational study comparing several openly available computer programs for solving the simple linear L ₁ regression problem with and without computing and utilizing a least squares solution.     

The Frisch–Waugh–Lovell theorem for the lasso and the ridge regression

The Frisch–Waugh–Lovell (FWL) (partitioned regression) theorem is essential in regression analysis. This is partly because it is quite useful to derive theoretical results. The lasso regression and the ridge regression, both of which are penalized least-squares regressions, have become popular statistical techniques. This article describes that the FWL theorem remains valid for these penalized least-squares regressions. More precisely, we demonstrate that the covariates corresponding to unpenalized regression parameters in these penalized least-squares regression can be projected out. Some other results related to the FWL theorem in such penalized least-squares regressions are also presented.     

On sequential closed testing dose groups with a control

Methods for a sequential test of a dose-response effect in pre-clinical studies are investigated. The objective of the test procedure is to compare several dose groups with a zero-dose control. The sequential testing is conducted within a closed family of one-sided tests. The procedures investigated are based on a monotonicity assumption. These closed procedures strongly control the familywise error rate while providing information about the shape of the dose-responce relationship. Performance of sequential testing procedures are compared via a Monte Carlo simulation study. We illustrae the procedures by application to a real data set.     

青海省入境旅游市场的态势分析及预测研究

随着中国入境旅游的迅速发展,青海省的入境旅游呈现出不同的态势。本文从海外游客客源地、客源国等方面对其进行了深入的分析,在此基础上进行了预测,并提出了可行性建议。     

Risk aggregation with dependence and overdispersion based on the compound Poisson INAR(1) process

Abstract

This paper considers an extension of the classical discrete time risk model for which the claim numbers are assumed to be temporal dependence and overdispersion. The risk model proposed is based on the first-order integer-valued autoregressive (INAR(1)) process with discrete compound Poisson distributed innovations. The explicit expression for the moment generating function of the discounted aggregate claim amount is derived. Some numerical examples are provided to illustrate the impacts of dependence and overdispersion on related quantities such as the stop-loss premium, the value at risk and the tail value at risk.     

Parameter estimation of Lindley step stress model with independent competing risk under type 1 censoring

Abstract

In literature, Lindley distribution is considered as an alternative to exponential distribution to fit lifetime data. In the present work, a Lindley step-stress model with independent causes of failure is proposed. An algorithm to generate random samples from the proposed model under type 1 censoring scheme is developed. Point and interval estimation of the model parameters is carried out using maximum likelihood method and percentile bootstrap approach. To understand the effectiveness of the resulting estimates, numerical illustration is provided based on simulated and real-life data sets.     

基于一种半开式滑槽球副的3-PSP并联平台设计

提出在并联机构中应用一种1移动3转动半开式滑槽球副结构,该运动副将1个移动副和1个球副集成为一个复合的运动副,可以缩短并联机构中支链的尺寸链,有助于提高并联机构精度。基于半开式滑槽球副设计了一种3自由度(3-DOF)PSP三轴并联平台,通过对此机构进行的运动分析和支链的精度分析,导出各个支链的逆解方程,同时根据影响支链运动精度的各个因素给出支链系统误差的线性补偿方程,证明此并联机构具有易于控制、运动精度高的优势。     

3D打印中CAD文件的定性与复制问题研究

3D打印技术的发展使著作权法上的复制变得更为高效便捷,由此产生了一系列亟待梳理和解决的问题。基于3D打印技术原理,可将其分为输入和输出两个环节。在输入环节,对CAD文件的作品类型进行规制,采用视觉标准界定立体作品,并以“美术作品+模型作品”的思路进行综合保护;在输出环节,3D打印属于复制,且可以实现从平面到立体和从立体到立体的复制形态,复制权的控制范围应不限于现行法律所列举的方式。针对3D打印技术在网络传播中的侵权风险,应对合理使用中的私人复制予以限制,灵活运用“三步检验标准”对合理性进行审查。3D打印在著作权法方面并未引发新的法律问题,现行制度已存在包容空间,不必为其特设著作权新规,通过对现有规则的解释和借助已有案例的适用经验便能解决可预见的著作权法争端。     

A new look at Markov processes of G/M/1-type

We present a new method for deriving the stationary distribution of an ergodic Markov process of G/M/1-type in continuous-time, by deriving and making use of a new representation for each element of the rate matrices contained in these distributions. This method can also be modified to derive the Laplace transform of each transition function associated with Markov processes of G/M/1-type.     

“海丝”战略背景下闽台海洋经济融合发展研究

党中央在新时期作出的共建21世纪海上丝绸之路的战略决策,对深化区域合作、推动全球经济发展具有重大的影响,更为闽台海洋经济融合发展提供了难得机遇。系统梳理和回顾改革开放以来闽台海洋经济合作的历程及成效,分析21世纪海上丝绸之路战略背景下闽台海洋经济融合发展的新机遇,提出闽台两地应充分发挥优势互补,坚持互利共赢原则,全面加强海洋渔业、航港造船产业、海洋科技产业和海洋观光游憩业的融合发展,共同推动闽台海洋开发合作向纵深发展。