Creating catalogues of two-level nonregular fractional factorial designs based on the criteria of generalized aberration

We consider the problem of constructing good two-level nonregular fractional factorial designs. The criteria of minimum G and G₂ aberration are used to rank designs. A general design structure is utilized to provide a solution to this practical, yet challenging, problem. With the help of this design structure, we develop an efficient algorithm for obtaining a collection of good designs based on the aforementioned two criteria. Finally, we present some results for designs of 32 and 40 runs obtained from applying this algorithmic approach.     

Uniformity pattern and related criteria for q-level factorials

The objective of this paper is to study the issue of the projection discrepancy along the line of Liu (2002) and Fang and Qin (2005) based on discrete discrepancy measure proposed in Qin and Fang (2004), which has wide application to the field of fractional factorials. Here we also study the projection properties for q-level factorials and provide connection between minimum projection uniformity and other optimality criteria. A lower bound to projection discrepancy for q-level factorials is presented here.     

Adaptive Isotonic Estimation of the Minimum Effective and Peak Doses in the Presence of Covariates

We consider a problem of estimating the minimum effective and peak doses in the presence of covariates. We propose a sequential strategy for subject assignment that includes an adaptive randomization component to balance the allocation to placebo and active doses with respect to covariates. We conclude that either adjusting for covariates in the model or balancing allocation with respect to covariates is required to avoid bias in the target dose estimation. We also compute optimal allocation to estimate the minimum effective and peak doses in discrete dose space using isotonic regression.     

Lower bounds and a tabu search algorithm for the minimum deficiency problem

An edge coloring of a graph G=(V,E) is a function c:E→ℕ that assigns a color c(e) to each edge e∈E such that c(e)≠c(e′) whenever e and e′ have a common endpoint. Denoting S _v (G,c) the set of colors assigned to the edges incident to a vertex v∈V, and D _v (G,c) the minimum number of integers which must be added to S _v (G,c) to form an interval, the deficiency D(G,c) of an edge coloring c is defined as the sum ∑ _v∈V D _v (G,c), and the span of c is the number of colors used in c. The problem of finding, for a given graph, an edge coloring with a minimum deficiency is NP-hard. We give new lower bounds on the minimum deficiency of an edge coloring and on the span of edge colorings with minimum deficiency. We also propose a tabu search algorithm to solve the minimum deficiency problem and report experiments on various graph instances, some of them having a known optimal deficiency.     

How Living Wage Legislation Affects U.S. Poverty Rates

I investigate how living wage legislation affects poverty. I find evidence that living wage ordinances modestly reduce poverty rates where such ordinances are enacted. However, there is no evidence that state minimum wage laws do so. The difference in the impacts of the two types of legislation conceivably stems from a difference in the party responsible for bearing the burden of the cost.

基于粘贴和删除系统求解最小权生成树的DNA算法

最小权生成树是一类典型的NP完全问题.粘贴和删除模型是DNA计算的两个基本计算模型.利用粘贴和删除模型给出求解最小权生成树问题的DNA算法.     

一种估计连续策略博弈的两阶段方法

 最近实证博弈研究的迅速发展为分析市场中的策略互动、进行政策分析与反事实实验提供了有效的工具。本文提出一种估计不完全信息连续策略博弈的两阶段方法,它可以处理私有信息的影响。第一阶段通过非参数分位数回归估计局中人的策略与期望支付函数;第二阶段利用贝叶斯——纳什均衡不等式构造模拟最小距离估计量,最终获得结构参数的估计。数值模拟显示本方法有良好的小样本表现。与现有文献的嵌套固定点方法相比,本方法不需计算均衡,极大地降低了计算量,并减轻了多重均衡的干扰。本方法既可以用于估计离散状态博弈,也适用于连续状态博弈。     

On some pre-test and Stein-rule phi-divergence test estimators in the independence model of categorical data

For the model of independence in a two way contingency table, shrinkage estimators based on minimum φ$\phi$-divergence estimators and φ$\phi$-divergence statistics are considered. These estimators are based on the James–Stein-type rule and incorporate the idea of preliminary test estimator. The asymptotic bias and risk are obtained under contiguous alternative hypotheses, and on the basis of them a comparison study is carried out.     

Moderate wage increases and flexible labour contracts to protect employment in Colombian manufacturing

Based on conditional and unconditional demands for labour, we exploit the variations of real minimum wage across manufacturing subsectors to present evidence that this variable affects formal employment. The long-term elasticity of labour demand to the minimum wage is around –0.7. Accordingly, increases in the minimum wage lead to job losses for unskilled labour, mainly in plants with fewer than 100; thus, small increases in the minimum wage are desirable to protect employment. Labour demand is highly cyclical: the output elasticity is about 1.7. Thus, some flexibility in labour contracts is desirable to reduce the link between employment and variation of plants’ sales. Open-ended labour contracts might allow reductions of the nominal wage rather than inducing job losses during periods of severe slumps, as has happened during the COVID-19 pandemic.