Monotone-path Dutta-Ray solutions on convex games

It is well known that on the domain of convex games, the Dutta-Ray solution satisfies many desirable properties such as population-monotonicity, max consistency, converse max consistency, and conditional self-consistency. In this paper, we define a family of possibly non-symmetric and non-homogeneous generalizations of the Dutta-Ray solution, which we refer to as “monotone-path Dutta-Ray solutions.” We show that above four properties are preserved by our generalizations. Received: 25 August 2000/Accepted: 11 September 2001     

A Test for Instrument Validity

This paper develops a specification test for instrument validity in the heterogeneous treatment effect model with a binary treatment and a discrete instrument. The strongest testable implication for instrument validity is given by the condition for nonnegativity of point‐identifiable compliers' outcome densities. Our specification test infers this testable implication using a variance‐weighted Kolmogorov–Smirnov test statistic. The test can be applied to both discrete and continuous outcome cases, and an extension of the test to settings with conditioning covariates is provided.     

Model selection for Lévy measures in diffusion processes with jumps from discrete observations

We deal with parametric inference and selection problems for jump components in discretely observed diffusion processes with jumps. We prepare several competing parametric models for the Lévy measure that might be misspecified, and select the best model from the aspect of information criteria. We construct quasi-information criteria (QIC), which are approximations of the information criteria based on continuous observations.     

The Influence of Maternal Socialization on Infants’ Social Evaluation in Two Cultures

Although a growing body of research has explored the early development of social evaluation, no research has directly compared social evaluations of infants between different cultures. In addition, there has been little understanding regarding socialization's effects on this ability. The goal of this study was to expand on earlier findings on social evaluation in infants by investigating a broader sample from two cultures, and to explore the influence of maternal socialization on infants’ social evaluation. Using the violation of expectations and the preferential reaching paradigm, four groups aged 6‐, 9‐, 12‐, and 15–18 months and their mothers from Japan and the United States (159 dyads) were compared in terms of spontaneous social evaluations. Japanese and European American infants showed similar performance in dishabituation to the inconsistent behavior and in their reaching preference for prosocial over antisocial agents, indicating that the emergence of spontaneous social evaluation is not culture‐specific. Furthermore, our study provides a novel finding regarding the relationship between mothers’ socially evaluative speech and infants’ preference for prosocial over antisocial agents. These results suggest that the development of sociomoral understanding results from complicated interactions among evolutionary, cognitive, and social factors.     

Threshold Estimation for Stochastic Processes with Small Noise

Consider a process satisfying a stochastic differential equation with unknown drift parameter, and suppose that discrete observations are given. It is known that a simple least squares estimator (LSE) can be consistent but numerically unstable in the sense of large standard deviations under finite samples when the noise process has jumps. We propose a filter to cut large shocks from data and construct the same LSE from data selected by the filter. The proposed estimator can be asymptotically equivalent to the usual LSE, whose asymptotic distribution strongly depends on the noise process. However, in numerical study, it looked asymptotically normal in an example where filter was chosen suitably, and the noise was a Lévy process. We will try to justify this phenomenon mathematically, under certain restricted assumptions.     

Development of the workflow kine systems for support on KAIZEN

In this paper, we introduce the new workflow line system consisted of the location and image recording, which led to the acquisition of workflow information and the analysis display. From the results of workflow line investigation, we considered the anticipated effects and the problems on KAIZEN. Workflow line information included the location information and action contents information. These technologies suggest the viewpoints to help improvement, for example, exclusion of useless movement, the redesign of layout and the review of work procedure. Manufacturing factory, it was clear that there was much movement from the standard operation place and accumulation residence time. The following was shown as a result of this investigation, to be concrete, the efficient layout was suggested by this system. In the case of the hospital, similarly, it is pointed out that the workflow has the problem of layout and setup operations based on the effective movement pattern of the experts. This system could adapt to routine work, including as well as non-routine work. By the development of this system which can fit and adapt to industrial diversification, more effective "visual management" (visualization of work) is expected in the future.     

Study on workloads of human care worker with the introduction of IT system - the characteristics of work loads by observational research and the suggestions for KAIZEN

The purpose of this study was to clarify the characteristic of workloads on human care worker with the introduction of IT system, and suggested the support measures for KAIZEN in Japan. The investigation method is workflow line and hearing with a focus on work observation. The objects were 8 human care workers of the acute hospital that introduced an electronic system. By the introduction of the electronic chart, the nurse station sojourn time decreased, sickroom sojourn time increased, and time about direct nursing care to a patient increased. In addition, access to patient information became easy, and the offer of the health care service based on correct information came to be possible in real time. By The point of workflow line, it was effect that moving lengths decreased in order to install the electronic chart in patients' rooms. Though, it was a problem that it hasn't formed where to place the instruments such as sphygmomanometer, clinical thermometer and others.     

Uniformly minimum variance unbiased estimation in lognormal and related distributions

The uniformly mimimum variance unbiased estimators and their variances from independent samples of lognormal distributions are concisely expressed using the hypergeometric functions     

Development of a Dose‐Response Model for SARS Coronavirus

In order to develop a dose‐response model for SARS coronavirus (SARS‐CoV), the pooled data sets for infection of transgenic mice susceptible to SARS‐CoV and infection of mice with murine hepatitis virus strain 1, which may be a clinically relevant model of SARS, were fit to beta‐Poisson and exponential models with the maximum likelihood method. The exponential model (k= 4.1 × l0²) could describe the dose‐response relationship of the pooled data sets. The beta‐Poisson model did not provide a statistically significant improvement in fit. With the exponential model, the infectivity of SARS‐CoV was calculated and compared with those of other coronaviruses. The does of SARS‐CoV corresponding to 10% and 50% responses (illness) were estimated at 43 and 280 PFU, respectively. Its estimated infectivity was comparable to that of HCoV‐229E, known as an agent of human common cold, and also similar to those of some animal coronaviruses belonging to the same genetic group. Moreover, the exponential model was applied to the analysis of the epidemiological data of SARS outbreak that occurred at an apartment complex in Hong Kong in 2003. The estimated dose of SARS‐CoV for apartment residents during the outbreak, which was back‐calculated from the reported number of cases, ranged from 16 to 160 PFU/person, depending on the floor. The exponential model developed here is the sole dose‐response model for SARS‐CoV at the present and would enable us to understand the possibility for reemergence of SARS.     

On umvu estimators for the multivariate lognormal distribution and their variances

Uniformly minimum variance unbiased estimators of several parameters of the multivariate lognormal distribution are expressed by using the hypergeometric functions of matrix argument. And the variances are given in special cases.