二元(二阶)线性递归关系解的周期性的简便判别法

本文给出了判别二元(二阶)线性递归关系解的周期的简便方法。     

概念、测量与机制：服务型领导研究述评

21世纪,企业的内部环境和外部环境发生着前所未有的变化,给企业领导与管理带来巨大挑战。其中,企业员工的工作需求逐渐从传统的解决温饱发展为渴望得到领导关注、尊重,传统的领导方式已经难以满足现代组织及员工的需求,服务型领导应运而生。服务型领导可以定义为：领导者秉持服务精神,通过体贴入微的服务行为,构建信任关系,促进团队成员成长、实现愿景的过程。但我国学者的相关研究还处于起步阶段。对服务型领导的早期文献进行梳理和归纳,评价现状并辨析缺失,以促进服务型领导的中国研究和本土应用。建议服务型领导的相关理论研究,包括测量工具、前因变量、结果变量、作用机制的探索和检验基于上述概念展开。     

Early Intervention into Addictive and Mental Health Disorders

No abstract available for this article.     

Predicting the Probability that a Chemical Causes Steatosis Using Adverse Outcome Pathway Bayesian Networks (AOPBNs)

Adverse outcome pathway Bayesian networks (AOPBNs) are a promising avenue for developing predictive toxicology and risk assessment tools based on adverse outcome pathways (AOPs). Here, we describe a process for developing AOPBNs. AOPBNs use causal networks and Bayesian statistics to integrate evidence across key events. In this article, we use our AOPBN to predict the occurrence of steatosis under different chemical exposures. Since it is an expert-driven model, we use external data (i.e., data not used for modeling) from the literature to validate predictions of the AOPBN model. The AOPBN accurately predicts steatosis for the chemicals from our external data. In addition, we demonstrate how end users can utilize the model to simulate the confidence (based on posterior probability) associated with predicting steatosis. We demonstrate how the network topology impacts predictions across the AOPBN, and how the AOPBN helps us identify the most informative key events that should be monitored for predicting steatosis. We close with a discussion of how the model can be used to predict potential effects of mixtures and how to model susceptible populations (e.g., where a mutation or stressor may change the conditional probability tables in the AOPBN). Using this approach for developing expert AOPBNs will facilitate the prediction of chemical toxicity, facilitate the identification of assay batteries, and greatly improve chemical hazard screening strategies.     

Expectations of Career Counseling and Their Effect on Client Satisfaction

Although there has been growing attention to clients' expectations of career counseling, more research is necessary to clarify the role of these expectations in shaping client satisfaction at the end of the intervention. On the basis of expectation confirmation theory, this study examined the indirect effect of clients' initial expectations on overall satisfaction through the perceived performance and final confirmation of expectations. We also explored whether this indirect effect is dependent on counselors' initial expectations. Longitudinal data were collected on 83 counselor-client dyads involved in a career counseling intervention in northeast Italy. Results confirmed that clients' initial expectations predicted overall satisfaction with the intervention through the subsequent mediation of perceived performance and confirmation of clients' expectations. The moderating role of the counselors' initial expectations was not confirmed. These findings imply that career counselors should invest their efforts in managing clients' expectations.     

A Note on Sample Size Determination for Akaike Information Criterion (AIC) Approach to Clinical Data Analysis

ABSTRACT

Because of its flexibility and usefulness, Akaike Information Criterion (AIC) has been widely used for clinical data analysis. In general, however, AIC is used without paying much attention to sample size. If sample sizes are not large enough, it is possible that the AIC approach does not lead us to the conclusions which we seek. This article focuses on the sample size determination for AIC approach to clinical data analysis. We consider a situation in which outcome variables are dichotomous and propose a method for sample size determination under this situation. The basic idea is also applicable to the situations in which outcome variables have more than two categories or outcome variables are continuous. We present simulation studies and an application to an actual clinical trial.     

Peer and Selection Effects on Youth Smoking in California

Previous research has found that youth smoking choices are strongly influenced by peer smoking. However, these studies often fail to account for simultaneity and nonrandom peer selection. This article describes an equilibrium model of peer effects that incorporates both of these features, and estimates its parameters using data on California teenagers. Identification is aided by using the influence of observable variables on group selection as a proxy for the influence of unobservables. I find that the effect of peer smoking on the decision to smoke is much weaker than found in previous studies.     

Participatory research meets validated outcome measures: Tensions in the co‐production of social care evaluation

Funding for care service research is increasingly subject to the satisfaction of two requirements: public involvement and adoption of validated outcome tools. This study identifies competing paradigms within these requirements and reveals significant challenges faced by researchers who seek to satisfy them. The focus here is on a study co‐produced between academic researchers and people with experience of adult social care services. It examines to what extent research studies can conduct high‐quality public involvement and genuine co‐production of knowledge, whilst attempting to produce quantifiable outcome scores. Findings add to debate around how to incorporate diverse perspectives in research, which may draw on incommensurate accounts of validity and reliability. Findings also highlight constructive attempts by academic and co‐researchers to make the combination of approaches work in the field. These small scale acts of researcher agency indicate some scope to combine the two approaches in future research studies. However, conclusions foreground the importance of broader awareness of how tensions and power imbalances related to this combination of approaches play out in social policy research practice.     

Approximating the equilibrium quantity traded and welfare in large markets

We consider the efficient outcome of a canonical economic market model involving buyers and sellers with independent and identically distributed random valuations and costs, respectively. When the number of buyers and sellers is large, we show that the joint distribution of the equilibrium quantity traded and welfare is asymptotically normal. Moreover, we bound the approximation rate. The proof proceeds by constructing, on a common probability space, a representation consisting of two independent empirical quantile processes, which in large markets can be approximated by independent Brownian bridges. The distribution of interest can then be approximated by that of a functional of a Gaussian process. This methodology applies to a variety of mechanism design problems.