Regions of alternatives with high and low power for goodness-of-fit tests

In the present paper we find finite dimensional spaces W of alternatives with high power for a given class of tests and non-parametric alternatives. On the orthogonal complement of W the power function is flat. These methods can be used to reduce the dimension of interesting alternatives. We sketch a device how to calculate (approximately) an alternative with maximum power of a fixed test on a given ball of certain non-parametric alternatives.

The calculations are done within different asymptotic models specified by signal detection tests. Specific tests are Kolmogorov–Smirnov type tests, integral tests (like the Anderson and Darling test) and Rényi tests for hazard based models. The statistical meaning and interpretation of the spaces of alternatives with high power is discussed. These alternatives belong to least favorable directions of a class of statistical functionals which are linear combinations of quantile functions. For various cases their meaning is explained for parametric submodels, in particular for location alternatives.     

论方豪对台湾史的研究

上个世纪五六十年代的台湾史研究 ,受“史料学派”的影响 ,大多学者埋首于整理史料 ,以辨别史料真伪、发掘原始史料为主 ,方豪即是其中较为杰出的代表。他在台湾史料的介绍与校订 ,尤其是整理研究方志方面做出了极大的贡献 ,这为后来的台湾史研究奠定了坚实的基础。直到今天 ,台湾史学界仍然对史料有着足够的重视。当然 ,在整理史料的基础上 ,方豪也做一些研究 ,其解释性观点也未能脱离当时的史学主流     

Signal crimes and signal disorders: notes on deviance as communicative action

In this paper a 'signal crimes' perspective is outlined in an effort to unpack the relationships between experiences of crime and disorder, and perceptions of criminogenic risk. Grounded in symbolic interactionist sociology, and developing a social semiotic understanding of risk perception, it is a perspective that focuses upon processes of social reaction and the ways in which people interpret and define threats to their security. It is proposed that people interpret the occurrence of certain incidents as 'warning signals' about the levels of risk to which they are either actually or potentially exposed. These signals tend to take the form of signal crimes and/or signal disorders and are important in terms of how social space is symbolically constructed.     

Phase-I monitoring of general linear profiles in multistage processes

In this article, the general linear profile-monitoring problem in multistage processes is addressed. An approach based on the U statistic is first proposed to remove the effect of the cascade property in multistage processes. Then, the T² chart and a likelihood ratio test (LRT)-based scheme on the adjusted parameters are constructed for Phase-I monitoring of the parameters of general linear profiles in each stage. Using simulation experiments, the performance of the proposed methods is evaluated and compared in terms of the signal probability for both weak and strong autocorrelations, for processes with two and three stages, as well as for two sample sizes. According to the results, the effect of the cascade property is effectively removed and hence each stage can be monitored independently. In addition, the result shows that the LRT approach provides significantly better results than the T² method and outperforms it under different shift and autocorrelation scenarios. Moreover, the proposed methods perform better when larger sample sizes are used in the process. Two illustrative examples, including a real case and a simulated example, are used to show the applicability of the proposed methods.     

Reproduction, juvenile survival and retention in an urban fox squirrel population

Fox squirrels in an urban environment had an average litter size of 2.83 (95% CI 2.5, 3.16) which was similar to rural populations. Nonetheless, the proportion of squirrels reproductively active during the summer/fall breeding season (0.73) and annually (spring + summer/fall) was higher (1.23) than previously recorded for non-manipulated rural populations. The average monthly survival rate () of urban juvenile fox squirrels during the first 14 weeks of life was higher than reported for adult populations in the area. High rates of reproduction and juvenile survival yielded high juvenile to adult ratios (juveniles/adults) averaging 0.44. Retention of juveniles after 6 months (15%) was significantly less (χ ² = 7.24, p = 0.0071) than adults/subadults (40%). Results suggest that the urban environment provides quality habitat for fox squirrels and fox squirrels in urban environments have the potential to be a source population for surrounding suburban and rural environments.     

On Simultaneous Estimation of the Number of Signals and Frequencies of Multiple Sinusoids When Some Observations Are Missing

In an earlier article (Bai et al., 1999 Bai , Z. D. , Rao , C. R. , Wu , Y. H. , Zen , M. M. , Zhao , L. C. ( 1999 ). The simultaneous estimation of the number of signals and frequencies of multiple sinusods when some observations are missing: I. Asymptotics . Proc. Natl. Acad. Sci. 96 : 11,106 – 11,110 . [CSA] [Crossref], [Web of Science ®] , [Google Scholar]), the problem of simultaneous estimation of the number of signals and frequencies of multiple sinusoids is considered in the case that some observations are missing. The number of signals is estimated with an information theoretic criterion and the frequencies are estimated with eigenvariation linear prediction. Asymptotic properties of the procedure are investigated but the Monte Carlo simulation is not performed. In this article, a slightly different but scale invariant criterion for detection is proposed and the estimation of frequencies remains the same. Asymptotic properties of this new procedure are provided. Monte Carlo Simulation for both procedures is carried out. Furthermore, comparison on the real signals is also given.     

A Benchmarking Approach to Temporal Disaggregation of Economic Time Series by Related Series

Several methods have been devised to deal with the problem of temporal disaggregation of economic time series (a) either when related series are available or (b) when only aggregate figures exist. In this article, we propose a statistical model-based approach to temporal disaggregation of economic time series by related series. The proposed approach is performed in two stages. In the first stage, we evaluate a preliminary estimate of the disaggregated series using a regression model for the disaggregated series and related series observed in the same frequency. The preliminary estimate of disaggregated series obtained in the first step is not consistent with aggregate figures. To ensure consistency we propose in the second stage, the use of a modified benchmarking approach based on signal extraction (Hillmer and Trabelsi, 1987 Hillmer , S. C. , Trabelsi , A. ( 1987 ). Benchmarking of economic time series . J. Amer. Statist. Assoc. 82 ( 400 ): 1064 – 1071 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]; Trabelsi and Hillmer, 1990 Trabelsi , A. , Hillmer , S. C. ( 1990 ). Benchmarking time series with reliable benchmarks . Appl. Statist. 39 ( 3 ): 367 – 379 .[Crossref], [Web of Science ®] , [Google Scholar]) to adjust the preliminary estimate of disaggregate series. The approach developed here is used for Seasonally Adjusted (SA) and Not Seasonally Adjusted (NSA) data. A comparison with previous temporal disaggregation methods has been done.     

An Evaluation of the Double Exponentially Weighted Moving Average Control Chart

In this article we perform a careful investigation of the double exponentially weighted moving average (DEWMA) chart performance for monitoring the process mean. We compare the performance of this chart to the usual EWMA control chart based on zero-state and worst-case average run length (ARL) measures. We also evaluate the signal resistance measure of the DEWMA chart and compare its maximum value to that of the EWMA chart. We show that the superiority of the DEWMA chart over the simpler standard EWMA chart based on zero-state ARL performance disappears when the smoothing constant of the EWMA chart is chosen to give weights to past observations closer to those given by the DEWMA chart. Moreover, our results show that the standard EWMA chart has much better performance than the DEWMA chart in terms of worst-case ARL values, especially when small smoothing constants are used. We also demonstrate using an illustrative example that the DEWMA chart can build up an exceedingly large amount of inertia when used to monitor the process mean.     

A Bayesian restoration of an ion channel signal

We present a Bayesian method of ion channel analysis and apply it to a simulated data set. An alternating renewal process prior is assigned to the signal, and an autoregressive process is fitted to the noise. After choosing model hyperconstants to yield 'uninformative' priors on the parameters, the joint posterior distribution is computed by using the reversible jump Markov chain Monte Carlo method. A novel form of simulated tempering is used to improve the mixing of the original sampler.     

Reframing child protection: A response to a constant crisis of confidence in child protection

Child protection systems appear to be in a continual crisis of confidence. They get criticised for not doing enough to protect some children, whilst at the same time being criticised for being too intrusive or not managing demand. This constant balancing act drives almost continual reforms, none of which appear to reduce further crises of confidence. The central issue facing tertiary child protection systems stems from their function as makers of sometimes highly uncertain risk screening decisions. Uncertainty leads to errors; false positives and false negatives. Two recurring issues challenging child protection agencies are concerns about these errors. Fears about doing too much are concerns about false positives and fears of doing too little are concerns about false negatives. The need to address both issues within the context of uncertain high stakes decision making, in a highly risk intolerant environment leads to poorly formed sentinel event driven policy that in turn leads to organisational fragility. A decision outcome-based performance model based on Signal Detection Theory provides indicators that explicitly outline the link between these two strategic issues facing child protection systems. This has improved dialogue, understanding and support from sponsors. It has led an informed focus on improving decision making and stabilisation of decision thresholds. It demonstrates that Child protection systems are in fact very responsive and do perform well in their decision making (risk screening) function. Social work decision makers provide value in their decision making in spite of highly uncertain decisions to make. Child protection systems do not need reform, they need to be “reframed” to better understand true performance and so avoid poorly informed reactive policy responses to the genuine challenges that they face.