A modification of the Whittaker–Henderson method of graduation

This paper presents a modified Whittaker–Henderson (WH) Method of Graduation. After giving a closed-form solution, we show that it is of practical use because it provides not only a smoothed series identical to that of the WH graduation, but also an extrapolation beyond the sample limit of current data. In addition, we introduce two other penalized least squares problems and show that they provide the same results as those of the modified WH graduation.     

How to Build an Intentional Android: Infants' Imitation of a Robot's Goal‐Directed Actions

This study examined whether young children are able to imitate a robot's goal‐directed actions. Children (24–35 months old) viewed videos showing a robot attempting to manipulate an object (e.g., putting beads inside a cup) but failing to achieve its goal (e.g., beads fell outside the cup). In 1 video, the robot made eye contact with a human before and after it failed the action. In another video, the robot did not make eye contact with the human adult. Only in the former condition did children “imitate” the robot's “intended” but unconsummated actions (e.g., putting beads inside a cup). When the robot did not make eye contact, children performed poorly, at the baseline level. These results suggest that human‐like gaze behaviors, not human‐like morphology, may play an important role in young children's imitation of a nonhuman agent's goal‐directed behaviors.     

Deterministic Õ(nm) Time Edge-Splitting in Undirected Graphs

This paper presents a deterministic O (nm log n + n2log2n) = Õ (nm) time algorithm for splitting off all edges incident to a vertex s of even degree in a multigraph G, where n and m are the numbers of vertices and links (= vertex pairs between which G has an edge) in G, respectively. Based on this, many graph algorithms using edge-splitting can run faster. For example, the edge-connectivity augmentation problem in an undirected multigraph can be solved in Õ (nm) time, which is an improvement over the previously known randomized Õ (n3) bound and deterministic Õ (n2m) bound.     

人虎山月间--中岛敦及其《山月记》解读

中岛敦生平与创作有三个特点 ,其代表作《山月记》与中国唐代传奇小说《人虎传》比较 ,两者有六大不同点 ,主人公李征的形象有一定的含义     

Interannual fluctuations in recruitment and growth of the sardine,Sardinops melanostictus, in the sea of Japan and adjacent waters

Recruitment and growth of the sardineSardinops melanostictus fluctuated markedly in the Sea of Japan and adjacent waters between 1978 and 1993. Stock size was calculated using Virtual Population Analysis and average body length in each age class was determined by the number of annual rings on the scales. There is an inverse correlation between average water temperature at a depth of 50 m in the coastal area of the mainland of Japan in winter (January to March) and recruitmentR defined as the number of individuals at 1 year old. There is also an inverse correlation between spawning stock sizeE and reproductive success in (R/E). A multiple regression model using spawning stock size and water temperature in winter as independent variables can explain 73% of variance in reproductive success. It suggests that both density-dependent and density-independent factors perform important roles determining reproductive success. There is an inverse correlation between body length and stock size and this suggests that there is a density-dependent effect on the growth of the sardine.     

An Assessment of Alternative Measures of Time Use

Although time use has received much attention by social scientists as an index of resource allocation and social relations across groups, only a few studies have carefully assessed the relative strengths and weaknesses of the existing methods of measuring time use: time diary (TD), stylized (S) respondent report, and experiential sampling method (ESM). We note the varying degree of biases that arise in part from the extent of detail in the information collected by the three methods. Using findings from our analysis of the structure of these methods, we hypothesize that there are empirical exceptions to previously reported common findings that TD provides less biased information on time use than does S—namely (a) when labor market workers report their time spent on labor market work, and (b) when the historical trend in time, rather than the absolute level, is studied. Empirical results confirm our prediction and show that, among individuals who work regularly, TD and S estimates of labor market work hours reported by the same persons correspond closely to one another. In addition, when assessing historical trends, TD and S values correspond closely to one another, although TDs yield some inexplicable deviations from the trend even when the sample and the codes are carefully standardized. We also provide notes on a strategy of standardization for diary codes that are distinct across historical or national contexts.     

Gender and the Internet

Objective. This article examines whether there are differences in men's and women's use of the Internet and whether any such gender gaps have changed in recent years. Methods. We use data from several surveys during the period 1997–2001 to show trends in Internet usage and to estimate regression models of Internet usage that control for individuals' socioeconomic characteristics. Results. Women were significantly less likely than men to use the Internet at all in the mid–1990s, but this gender gap in being online disappeared by 2000. However, once online, women remain less frequent and less intense users of the Internet. Conclusions. There is little reason for concern about sex inequalities in Internet access and usage now, but gender differences in frequency and intensity of Internet usage remain.     

Principal points for an allometric extension model

A set of \(n\) -principal points of a \(p\) -dimensional distribution is an optimal \(n\) -point-approximation of the distribution in terms of a squared error loss. It is in general difficult to derive an explicit expression of principal points. Hence, we may have to search the whole space \(R^p\) for \(n\) -principal points. Many efforts have been devoted to establish results that specify a linear subspace in which principal points lie. However, the previous studies focused on elliptically symmetric distributions and location mixtures of spherically symmetric distributions, which may not be suitable to many practical situations. In this paper, we deal with a mixture of elliptically symmetric distributions that form an allometric extension model, which has been widely used in the context of principal component analysis. We give conditions under which principal points lie in the linear subspace spanned by the first several principal components.     

A theorem on the covariance matrix of a generalized least squares estimator under an elliptically symmetric error

In a general linear regression model, a generalized least squares estimator (GLSE) is widely employed as an estimator of regression coefficient. The efficiency of the GLSE is usually measured by its covariance (or risk) matrix. In this paper, it is shown that the covariance matrix remains the same as long as the distribution of the error term is elliptically symmetric. This implies that every efficiency result obtained under normal distribution assumption is still valid under elliptical symmetry. An application to a heteroscedastic linear model is also illustrated.