Inverse Combinatorial Optimization: A Survey on Problems, Methods, and Results

Given a (combinatorial) optimization problem and a feasible solution to it, the corresponding inverse optimization problem is to find a minimal adjustment of the cost function such that the given solution becomes optimum.Several such problems have been studied in the last twelve years. After formalizing the notion of an inverse problem and its variants, we present various methods for solving them. Then we discuss the problems considered in the literature and the results that have been obtained. Finally, we formulate some open problems.     

针对学前教育专业男生发音问题的研究与分析

目前,学前教育专业男生朗读技能训练的课程中,在发音上存在着声母和韵母发音混淆的问题。男生的舌尖敏感度明显不如女生。男生在练习时要分清发音部位,了解发音方法,学会控制气息。教师要训练男生依靠发音部位和发音方法之间的准确配合,利用对气息的控制,真正掌握正确读出声母的诀窍。男生要学会灵活运用口腔和舌头,掌握每个元音发音时口腔的开合度,舌面的高低升降,唇形的圆展变化,克服弱点,多练多学,纠正发音问题。要提高朗读水平,男生自己的内因,即主动学习的态度十分关键。     

Maternal Discipline and Children's Adjustment: The Role of the Cultural and Situational Context

This study examined how the cultural and situational contexts can jointly shape the consequences of discipline strategies. Israeli mothers who grew up in Israel or in the Former Soviet Union (FSU) (overall N = 110) reported regarding their use of psychologically controlling and punitive discipline with their seven‐years‐old to 10‐years‐old children, and teachers reported regarding children's behavior problems. We assessed both mothers' overall general use of the discipline strategies, and their use of the same strategies following transgressions in the academic domain, an area which the two groups emphasize to differing degrees. Consistent with hypothesis, controlling discipline in academic situations had more positive consequences in the FSU group compared with the Israeli‐origin group. In contrast, and as predicted, cultural group was not a moderator of mothers' overall, general use of the same discipline strategies. The findings illustrate how taking the situation into account can inform examination of the moderating role of cultural group.     

Approach and Positive Affect in Toddlerhood Predict Early Childhood Behavior Problems

The aim of the study was to examine the moderating role of positive affect on the relation between approach behaviors and adjustment outcomes. One hundred eleven toddlers participated in a laboratory assessment of approach and positive affect at 24 months. Behavior problems were reported by a parent in the fall of the child's kindergarten year. Results supported our hypotheses that children who displayed high approach and high positive affect in both non‐threat and low‐threat contexts were rated as higher in externalizing behavior problems. On the other hand, for children showing low positive affect, increases in approach in a moderate‐threat context lowered the risk of developing internalizing behavior problems. Implications for these findings are discussed, including methodological considerations of differences among eliciting contexts and advantages of separating positive affect and approach.     

‘Youth is Present Only When Its Presence is a Problem’: Voices of Young People on Discipline in School

Discipline in schools is a topic of enduring public interest and concern. This article reviews findings from three recent research studies, which gathered views of young people on this issue in mainstream, alternative and special school settings. It reveals the confusion and frustration of students seeking to contribute to the debate, often on aspects that affect them directly and significantly. Their reflections are contextualised within a discussion of different conceptualisations of discipline, and from there, it is argued that, by strengthening the voice, power and presence of young people in dialogue on this key issue, the debate itself will be more relevant and well‐focused.     

当前我国社会组织培育和发展中的问题与对策

努力培育和发展社会组织,尽快形成党委领导、政府负责、社会协同、公众参与的公共服务和公共管理新格局,以便提供更多更好的公共服务和公共物品,使人民群众能够在更高水平上实现安居乐业,是我们面临的新历史使命.归纳当前我国社会组织培育和发展工作中形成的新认识,揭示我国社会组织培育和发展中现存的主要问题并探讨解决问题的对策,可为我国社会组织培育和发展工作的有效展开提供借鉴.     

Record-breaking data: a parametric comparison of the inverse-sampling and the random-sampling schemes

In many industrial quality control experiments and destructive stress testing, the only available data are successive minima (or maxima)i.e., record-breaking data. There are two sampling schemes used to collect record-breaking data: random sampling and inverse sampling. For random sampling, the total sample size is predetermined and the number of records is a random variable while in inverse-sampling the number of records to be observed is predetermined; thus the sample size is a random variable. The purpose of this papper is to determinevia simulations, which of the two schemes, if any, is more efficient. Since the two schemes are equivalent asymptotically, the simulations were carried out for small to moderate sized record-breaking samples. Simulated biases and mean square errors of the maximum likelihood estimators of the parameters using the two sampling schemes were compared. In general, it was found that if the estimators were well behaved, then there was no significant difference between the mean square errors of the estimates for the two schemes. However, for certain distributions described by both a shape and a scale parameter, random sampling led to estimators that were inconsistent. On the other hand, the estimated obtained from inverse sampling were always consistent. Moreover, for moderated sized record-breaking samples, the total sample size that needs to be observed is smaller for inverse sampling than for random sampling.     

Model Checks in Inverse Regression Models with Convolution‐Type Operators

Abstract. We consider the problem of testing parametric assumptions in an inverse regression model with a convolution‐type operator. An L ₂ ‐type goodness‐of‐fit test is proposed which compares the distance between a parametric and a non‐parametric estimate of the regression function. Asymptotic normality of the corresponding test statistic is shown under the null hypothesis and under a general non‐parametric alternative with different rates of convergence in both cases. The feasibility of the proposed test is demonstrated by means of a small simulation study. In particular, the power of the test against certain types of alternative is investigated. Finally, an empirical example is provided, in which the proposed methods are applied to the determination of the shape of the luminosity profile of the elliptical galaxy NGC 5017.     

Public relations critical intersections special section introduction

The theme of this special section arose from the idea that interdisciplinary interactions, or the cross-fertilization of methods, philosophies, theories, and modes of practice across disciplines, can open out productive ways of addressing complex issues and wicked problems. Our call for papers reached out to public relations scholars and to researchers in other fields to submit articles at these generative intersections at different time. They were invited to reflect on traditional concerns, or current issues, or projected trends in public relations and elsewhere. As editors making a call to open boundaries, we invited participation along a spectrum of possible intersections whether of content, methods, pedagogy or technology. Taking different positions on that spectrum, the articles in the section examine the nature, engagement and evaluation of intersections. In writing this introduction, the editors took an overview of the articles in the light of three fundamental questions: “How and where does interdisciplinarity occur in public relations?”; “Are there indications of how public relations intersects with other fields to engage existing and potential future challenges?”; and “What principles might serve to evaluate answers to questions one and two?” In addition, we explore how each of the selected intersections in the articles might add value to public relations as a discipline and a practice.     

Treatment Evaluation in the Presence of Sample Selection

Sample selection and attrition are inherent in a range of treatment evaluation problems such as the estimation of the returns to schooling or training. Conventional estimators tackling selection bias typically rely on restrictive functional form assumptions that are unlikely to hold in reality. This paper shows identification of average and quantile treatment effects in the presence of the double selection problem into (i) a selective subpopulation (e.g., working—selection on unobservables) and (ii) a binary treatment (e.g., training—selection on observables) based on weighting observations by the inverse of a nested propensity score that characterizes either selection probability. Weighting estimators based on parametric propensity score models are applied to female labor market data to estimate the returns to education.