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.     

A simulation study of methods for selecting subgroup‐specific doses in phase 1 trials

Patient heterogeneity may complicate dose‐finding in phase 1 clinical trials if the dose‐toxicity curves differ between subgroups. Conducting separate trials within subgroups may lead to infeasibly small sample sizes in subgroups having low prevalence. Alternatively,it is not obvious how to conduct a single trial while accounting for heterogeneity. To address this problem,we consider a generalization of the continual reassessment method on the basis of a hierarchical Bayesian dose‐toxicity model that borrows strength between subgroups under the assumption that the subgroups are exchangeable. We evaluate a design using this model that includes subgroup‐specific dose selection and safety rules. A simulation study is presented that includes comparison of this method to 3 alternative approaches,on the basis of nonhierarchical models,that make different types of assumptions about within‐subgroup dose‐toxicity curves. The simulations show that the hierarchical model‐based method is recommended in settings where the dose‐toxicity curves are exchangeable between subgroups. We present practical guidelines for application and provide computer programs for trial simulation and conduct.     

Minimum variance unbiased estimation of stress–strength reliability under bivariate normal and its comparisons

In many industrial and natural phenomena, we need the probability that a component is smaller than the other component. Under a stress–strength model, this is reliability of an item. Under independent setup, there are different approaches for the estimation of such reliability. Here, estimation is considered under the dependent case. Under bi-variate setup uniformly minimum variance unbiased estimator is obtained. Also comparison with available estimator based on Maximum Likelihood Estimate (MLE) is done through Mean Square Error (MSE) and bias. Also these are compared by computing L₁ distance between their distribution functions. From this idea and numerical computations, UMVUE appears to be good.     

Attitude strength moderates adverse effects to questionnaire design

ABSTRACT

The presentation and visual design of the “don’t know” category in rating scales on respondents’ behavior may have ambivalent effects. The hypothesis is that attitude strength toward the topic influences the respondents’ sensitivity to the graphical design of the scale. A paper-and-pencil questionnaire conducted among 307 German university students contained an experimental variation of the presentation of a “don’t know” category and its visual design. A multinomial logistic regression shows that presenting a “don’t know” category drives respondents toward extreme categories. The visual design of the “don’t know” category influences the distribution of responses, all the more that the respondents’ attitudes toward the item topic are weak.     

Lurking Behavior in Online Psychosocial Discussion Forums: Theoretical Perspectives and Implications for Practice

Improving outcomes of telebehavioral psychoeducation requires rethinking program design when delivered wholly or partially for self-directed participation. Discussion forum participation often follows the “90-9-1 Rule” where 90% of participants lurk, rather than contribute content. A theoretical perspective on the behavior can help explain its adaptive functions, as well as the threats that this behavior poses to the lurker. Implications for practice require program redesign that actively links individual skills training and group-based discussion. The proposed linking design can synergize individual and group participation to support the development of mutual aid, as well as greater interaction with psychoeducation content and materials.     

From salons to the native reserve: reformulating the “native question” through pictorial photography in 1950s South Africa

The article provides a critical reflection on the practice of photographic salon exhibitions in the 1950s. In South Africa and abroad, there was a resurgence of photographic societies from the early 1950s that encouraged amateur photographers to create images based on a distinct visual grammar, thereby offering them not only an opportunity to display their work but to compete amongst each other. Subsequently, salon exhibitions produced work that would be judged on its pictorial rather than strict representational value thereby depoliticising the exhibition space. On the other hand, this article seeks to place this practice in the realm of racial segregation under apartheid by considering the deployment of the “black subject” in the native rural reserve in Joseph Denfield’s (1911–1967) work. Through a study of his ethnographic photographs which were exhibited internationally in this period as pictorial work, as well as his intellectualisation of his practice as native photography, it argues that the space of the salon allowed him to pose the “native question” pictorially, that is, provided a discourse through which the “native” could be “known” and ordered.     

《儿女英雄传》中的副词“都”及其语法化

《儿女英雄传》是《红楼梦》通向现代北京话的中途站,通过它可以了解汉语在19世纪中期的基本面貌。当时,副词“都”已具备表示范围和表示语气等用法,其语气副词用法中有一类兼表已然义。根据《儿女英雄传》中反映的语言事实和语法化的一般规律,副词“都”的语法化路径应该为“范围副词→语气副词→兼表已然义的语气副词”。     

“无厘头”的影片观看及审美效果的形成

对于“无厘头”影片作为一种文化现象的研究很多,但却少有涉及穿插“无厘头”桥段如何对影片造成影响以及如何形成最终审美效果等观影过程的探讨。自电影符号学之后开始出现影片细读和精神分析取向,而德勒兹哲学则试图对传统的精神分析模式进行改造,将电影的观看视为强度流的物质实践活动。基于此,“无厘头”电影的观看可以看作镜头流与观看的观众身体流的汇合。把镜头流视为叙述文本,通过内在于文本的叙述逻辑（符号意指链的断裂／重组）之间张力的解读,在大量的镜头分析中总结出影片穿插“无厘头”桥段、形成审美效果的规律,并在三阶段的区分中分析张力强度与剧情认同程度关系所造成的影片整体审美效果变动。     

“双积分”政策下汽车制造商竞争定价与减排策略研究

"双积分"政策的实施对汽车制造商的定价决策产生了重要影响。考虑卖方由同时生产燃油车和新能源汽车的制造商1和仅生产新能源汽车的制造商2组成,在消费者低碳偏好和价格竞争影响下分别针对制造商1对燃油车采取和不采取节能减排措施的情况,研究"双积分"政策下汽车制造商的定价策略和减排决策,探讨新能源汽车积分值和积分比例要求对政府和企业决策的作用效果。进一步,通过对不同情形的结果进行分析,得到"双积分"政策的出台、消费者低碳偏好及制造商采取节能减排措施对制造商定价和减排决策带来的变化,并通过算例分析验证了结论。研究结果表明:(1)"双积分"政策可以降低新能源汽车的价格,提高新能源汽车制造商的利润,促进燃油车主动减排。(2)当新能源汽车的需求价格弹性系数和需求交叉价格弹性系数处于较高水平时,政府要制定较高的每台新能源汽车积分值。(3)燃油车的油耗水平存在一个环境属性标准,当油耗水平低于一定值时,随着新能源汽车积分比例要求的不断增大,制造商1选择提高燃油车价格。(4)消费者低碳偏好是提高燃油车减排水平的重要因素,政府可以对减排技术先进的燃油车制造商进行低油耗认证,提高消费者低油耗燃油车需求,激励燃油车制...     

汉英新闻翻译中的词汇迁移及分析

新闻翻译是对外宣传的主要途径之一，准确而有效地翻译不仅涉及信息的有效传达，而且事关我们的国际形象。本文结合新闻英译中的一些实例，从语言迁移的角度分析新闻英译过程中一些词汇翻译的不当之处进行剖析，以探讨如何实现准确、有效的翻译。