Additive outliers in INAR(1) models

In this paper the integer-valued autoregressive model of order one, contaminated with additive outliers is studied in some detail. Moreover, parameter estimation is also addressed. Supposing that the timepoints of the outliers are known but their sizes are unknown, we prove that the conditional least squares (CLS) estimators of the offspring and innovation means are strongly consistent. In contrast, however, the CLS estimators of the outliers’ sizes are not strongly consistent, although they converge to a random limit with probability 1. We also prove that the joint CLS estimator of the offspring and innovation means is asymptotically normal. Conditionally on the values of the process at the timepoints neighboring to the outliers’ occurrences, the joint CLS estimator of the sizes of the outliers is also asymptotically normal.     

False Alarms and Missed Events: The Impact and Origins of Perceived Inaccuracy in Tornado Warning Systems

Theory and conventional wisdom suggest that errors undermine the credibility of tornado warning systems and thus decrease the probability that individuals will comply (i.e., engage in protective action) when future warnings are issued. Unfortunately, empirical research on the influence of warning system accuracy on public responses to tornado warnings is incomplete and inconclusive. This study adds to existing research by analyzing two sets of relationships. First, we assess the relationship between perceptions of accuracy, credibility, and warning response. Using data collected via a large regional survey, we find that trust in the National Weather Service (NWS; the agency responsible for issuing tornado warnings) increases the likelihood that an individual will opt for protective action when responding to a hypothetical warning. More importantly, we find that subjective perceptions of warning system accuracy are, as theory suggests, systematically related to trust in the NWS and (by extension) stated responses to future warnings. The second half of the study matches survey data against NWS warning and event archives to investigate a critical follow‐up question—Why do some people perceive that their warning system is accurate, whereas others perceive that their system is error prone? We find that subjective perceptions are—in part—a function of objective experience, knowledge, and demographic characteristics. When considered in tandem, these findings support the proposition that errors influence perceptions about the accuracy of warning systems, which in turn impact the credibility that people assign to information provided by systems and, ultimately, public decisions about how to respond when warnings are issued.     

The Influence of Value Orientations,Personal Beliefs,and Knowledge about Resource Extraction on Local Leaders' Positions on Shale Development

Unconventional shale oil and gas production plays a prominent role in boosting economic growth and stimulating wealth creation in many communities. However, because of potential social and environmental drawbacks, including a lack of affordable housing and groundwater contamination from drilling, unconventional shale development is highly contentious in many areas and has resulted in many community conflicts. Hydraulic fracturing, which is a specific technology utilized in unconventional shale development, has proved especially contentious because of concerns about its long‐term environmental consequences. Given the fast pace of shale development, coupled with the controversy that surrounds it, we seek to understand what factors affect a local government official's stance on shale development and hydraulic fracturing. To do this we draw from value‐belief‐norms theory while additionally examining knowledge and community‐level factors that can influence an official's position. In this study, we survey 308 local government officials across six shale plays in the United States to examine local officials' positions on shale development and hydraulic fracturing. We find that the more positively officials perceive the consequences of shale development, the less likely they are to support banning hydraulic fracturing. Additionally, we find that networks to other shale communities are positively associated with favoring a ban. Further, leaders with a bachelor's degree or higher are more likely to favor a ban than those with lower than a bachelor's degree.     

An alternative procedure for performing a power analysis of Mantel's test

This study proposes a simple way to perform a power analysis of Mantel's test applied to squared Euclidean distance matrices. The general statistical aspects of the simple Mantel's test are reviewed. The Monte Carlo method is used to generate bivariate Gaussian variables in order to create squared Euclidean distance matrices. The power of the parametric correlation t-test applied to raw data is also evaluated and compared with that of Mantel's test. The standard procedure for calculating punctual power levels is used for validation. The proposed procedure allows one to draw the power curve by running the test only once, dispensing with the time demanding standard procedure of Monte Carlo simulations. Unlike the standard procedure, it does not depend on a knowledge of the distribution of the raw data. The simulated power function has all the properties of the power analysis theory and is in agreement with the results of the standard procedure.     

The Rate of Convergence of some Asymptotic Expansions for Distribution Approximations via an Esseen Type Estimate

Some asymptotic expansions not necessarily related to the central limit theorem are studied. We first observe that the smoothing inequality of Esseen implies the proximity, in the Kolmogorov distance sense, of the distributions of the random variables of two random sequences satisfying a sort of general asymptotic relation. We then present several instances of this observation. A first example, partially motivated by the the statistical theory of high precision measurements, is given by a uniform asymptotic approximation to (g(X + μ _n )) _n∈?, where g is some smooth function, X is a random variable and (μ _n ) _n∈? is a sequence going to infinity; a multivariate version is also stated and proved. We finally present a second class of examples given by a randomization of the interesting parameter in some classical asymptotic formulas; namely, a generic Laplace's type integral, randomized by the sequence (μ _n X) _n∈?, X being a Gamma distributed random variable.     

A demand classification scheme for spare part inventory model subject to stochastic demand and lead time

In this study, we aim to develop a demand classification methodology for classifying and controlling inventory spare parts subject to stochastic demand and lead time. Using real data, the developed models were tested and their performances were evaluated and compared. The results show that the Laplace model provided superior performance in terms of service level, fill rate (FR) and inventory cost. Compared with the current system based on normal distribution, the proposed Laplace model yielded significant savings and good results in terms of the service level and the FR. The Laplace and Gamma optimisation models resulted in savings of 82 and 81%, respectively.     

Quality of life and sustainability issues as seen by the population of low-income housing in the region of Campinas, Brazil

This paper presents a study on quality of life and sustainability indicators relating to site-planning parameters for low-income public housing projects in the region of Campinas, Brazil. The study is based on a post-occupancy-evaluation (POE), conducted in five housing developments. Most of these housing projects are based on a repetitive model and are devoid of urban infrastructure. Users act on their own in providing for some elements considered necessary to create an identity and community spirit. Results show that the population relates quality of life to economic factors and sustainability is associated to reduce utility bills. Houses are preferred to apartments and satisfaction with the present housing conditions is high, despite low feelings of security in the neighbourhood. This work is part of a broader study, which aims to develop design evaluation tools. Most sensitive quality of life and sustainability indicators related to site-planning should permeate these tools and establish design guidelines. The inclusion of a large number of qualitative design issues into the decision-making process and the questioning of existing standardized solutions are seen as essential means to increase local housing quality.     

入世后的中国工业设计教育

文章针对我国入世后工业设计将面临的挑战, 就教学观念上如何规范工业设计教学, 教学内容上如何进一步与国际接轨以及对产品设计课程的教学目的与方法提出了自己的看法。     

论我国蚕丝业的多中心起源

中国是世界蚕丝业的发源地,蚕丝业起源的时间下限在新石器时代晚期,距今至少在5500年以上.中国蚕丝业起源是多中心的,黄河中下游流域、长江中下游流域和四川盆地的三江流域都是蚕丝业的起源地之一.