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1.
Modeling spatial overdispersion requires point process models with finite‐dimensional distributions that are overdisperse relative to the Poisson distribution. Fitting such models usually heavily relies on the properties of stationarity, ergodicity, and orderliness. In addition, although processes based on negative binomial finite‐dimensional distributions have been widely considered, they typically fail to simultaneously satisfy the three required properties for fitting. Indeed, it has been conjectured by Diggle and Milne that no negative binomial model can satisfy all three properties. In light of this, we change perspective and construct a new process based on a different overdisperse count model, namely, the generalized Waring (GW) distribution. While comparably tractable and flexible to negative binomial processes, the GW process is shown to possess all required properties and additionally span the negative binomial and Poisson processes as limiting cases. In this sense, the GW process provides an approximate resolution to the conundrum highlighted by Diggle and Milne. 相似文献
2.
《Risk analysis》2018,38(9):1988-2009
Harbor seals in Iliamna Lake, Alaska, are a small, isolated population, and one of only two freshwater populations of harbor seals in the world, yet little is known about their abundance or risk for extinction. Bayesian hierarchical models were used to estimate abundance and trend of this population. Observational models were developed from aerial survey and harvest data, and they included effects for time of year and time of day on survey counts. Underlying models of abundance and trend were based on a Leslie matrix model that used prior information on vital rates from the literature. We developed three scenarios for variability in the priors and used them as part of a sensitivity analysis. The models were fitted using Markov chain Monte Carlo methods. The population production rate implied by the vital rate estimates was about 5% per year, very similar to the average annual harvest rate. After a period of growth in the 1980s, the population appears to be relatively stable at around 400 individuals. A population viability analysis assessing the risk of quasi‐extinction, defined as any reduction to 50 animals or below in the next 100 years, ranged from 1% to 3%, depending on the prior scenario. Although this is moderately low risk, it does not include genetic or catastrophic environmental events, which may have occurred to the population in the past, so our results should be applied cautiously. 相似文献
3.
Aggressive behavior in pet dogs is a serious problem for dog owners across the globe, with bite injuries representing a serious risk to both people and other dogs. The effective management of aggressive behavior in dogs represents a challenging and controversial issue. Although positive reinforcement training methods are now considered to be the most effective and humane technique to manage the risk of aggression, punishment‐based methods continue to be used. Unfortunately, there has been little scientific study into the various factors influencing whether dog owners choose to use positive reinforcement techniques to manage aggression in their dogs. As such, current understanding of how best to encourage and support dog owners to use these methods remains extremely limited. This article uses a survey methodology based on protection motivation theory (PMT) to investigate the factors that influence owner use of positive reinforcement methods to manage aggressive behavior, in an attempt to understand potential barriers and drivers of use. In addition, the article provides an initial exploration of the potential role of wider psychological factors, including owner emotional state, social influence, and cognitive bias. Findings show that the perceived efficacy of positive reinforcement methods and the perceived ability of owners to effectively implement the technique are both key factors predicting future intentions and current reported use. Future interventions should focus on enhancing owner confidence in the effective use of positive reinforcement techniques across multiple scenarios, as well as helping owners manage their own emotional responses when they encounter challenging situations and setbacks. 相似文献
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Hadi Emami 《统计学通讯:理论与方法》2020,49(8):1793-1800
AbstractIn this article we develop the minimax estimation approach of general linear models to the semiparametric linear models when the parameters are simultaneously constrained by an ellipsoid and linear restrictions. Combining sample information and prior constraints the minimax estimator is obtained and compared with partially least square estimator by theoretical and simulation methods. 相似文献
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汪洪斌 《湖南文理学院学报(社会科学版)》2002,27(2):27-29
早期共产主义者学习和利用马列主义政党学说的基本原理来解决在中国建立政党的过程中遇到的具体问题,提出为什么要建立政党、如何建立和建设政党等党建根本问题。 相似文献
8.
袁晖坪 《上海理工大学学报(社会科学版)》2002,24(3):214-217,221
给出了复亚半正定矩阵的概念,研究了它的基本性质及行列式理论,将Hermite阵的Schur定理,华罗庚定理,Minkowski不等式,凸性不等式,Ostrowski-Taussky不等式推广到了较广泛的复矩阵类,扩大了Minkowski不等式的指数范围,削弱了华罗庚不等式的条件。 相似文献
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利用全微分方程的条件,给出一类微分方程的积分因子及通解公式,得出一类全微分方程中未知函数所满足的二阶线性微分方程,获得未知函数及全微分方程的通解。 相似文献
10.
天波 《广西师范学院学报(哲学社会科学版)》2002,23(2):62-65
乾隆三十三年 ,纪昀因为“漏言”被谪贬至西域乌鲁木齐。与古代其他谪贬文人所不同的是 ,他并未完全沉浸于穷愁怨艾的情绪中 ,而是以积极乐观的人生态度面对现实。他的《乌鲁木齐杂诗》及《阅微草堂笔记》多方面地展示了西域的风土人情。但两者在内容及视角上有所不同 ,《乌鲁木齐杂诗》以丰富见长 ,但多粉饰之意 ;《阅微草堂笔记》以深刻取胜 ,真实而颇见其洞察力 相似文献