A Bayesian Analysis of Abundance,Trend, and Population Viability for Harbor Seals in Iliamna Lake,Alaska

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.     

工业企业经济效益综合评价与分析

利用SPSS软件,对我国31个省、直辖市的大中型工业企业的总资产贡献率、成本费用利润率、资本保值增值率、流动资产周转次数、全员劳动生产率、产品销售率、资产负债率、总资产周转率、净资产收益率、销售利润率等十个经济效益指标进行了因子分析,并将这十个指标归结为盈利、销售、运营、发展等多个因子。最后,根据每个因子得分情况将所有地区归为六类,进而做出综合评价。     

虢国车马坑葬初探

三门峡上村岭虢国墓地车马坑是迄今为止发现的西周春秋时期规模较大、等级齐全、排列有序的贵族墓祔葬车马坑。虢国车马坑葬继承和沿用商周车马殉葬制，又适应和迎合社会进步及变革需要，对车马坑的殉葬内容和形式进行变通与革新，摒弃车葬坑和同穴葬，整车葬成为主流形式，并盛行车马葬和异穴葬，车马排列有序，殉葬性质更加明确，是象征性、明器化殉葬的滥觞，殉人制消失，显示出传统车马坑葬制开始出现瓦解的苗头。大量车马坑葬在虢国墓地出现，反映了虢国生产力发展水平和崇勇尚武世风，更反映了车马坑主人的身份等级，它与列鼎制紧密配合，形成了一个不可分割的整体。     

On Block Updating in Markov Random Field Models for Disease Mapping

Gaussian Markov random field (GMRF) models are commonly used to model spatial correlation in disease mapping applications. For Bayesian inference by MCMC, so far mainly single-site updating algorithms have been considered. However, convergence and mixing properties of such algorithms can be extremely poor due to strong dependencies of parameters in the posterior distribution. In this paper, we propose various block sampling algorithms in order to improve the MCMC performance. The methodology is rather general, allows for non-standard full conditionals, and can be applied in a modular fashion in a large number of different scenarios. For illustration we consider three different applications: two formulations for spatial modelling of a single disease (with and without additional unstructured parameters respectively), and one formulation for the joint analysis of two diseases. The results indicate that the largest benefits are obtained if parameters and the corresponding hyperparameter are updated jointly in one large block. Implementation of such block algorithms is relatively easy using methods for fast sampling of Gaussian Markov random fields ( Rue, 2001 ). By comparison, Monte Carlo estimates based on single-site updating can be rather misleading, even for very long runs. Our results may have wider relevance for efficient MCMC simulation in hierarchical models with Markov random field components.     

基于递阶生产系统投入产出模型的企业生产经营决策优化应用的研究

本文基于递阶生产系统投入产出模型,以某锦纶厂为应用背景,在建立销售结构优化模型的基础上,对企业销售结构优化、企业内部潜力挖掘和产品定价等几个方面的经营决策优化问题进行了探讨,并进行了成功的实践。     

税务信息管理权与保护权的冲突与平衡

实践中税务机关与纳税人在信息采集、保有及使用方面存在激烈冲突。究其原因在于公权力与私权利冲突具有必然性、税务信息的权利（力）边界不明且经济性日益凸显及税务机关信息管理的责任机制不健全。借鉴域外经验,中国税务机关信息管理权与纳税人信息保护权的平衡之道在于限制公权力并进一步保障私权利,坚持税收法定、个人权利保护及狭义比例等原则。具体而言,需明确税务机关信息管理权与纳税人信息保护权的范围,构建税务信息分层管理机制,严格化税务机关信息管理的程序,完善纳税人信息的争端解决机制与违法取用纳税人信息的责任机制并加强对税务机关信息管理权的监督,促进税务信息领域的公权力与私权利从冲突中走向平衡。     

内外部网络口碑与在线销售的动态交互过程——基于分层贝叶斯模型的解析

与以往单纯以内部网络口碑、相互独立的内部和外部网络口碑为研究对象,分析网络口碑与在线销售的关系不同。基于评论环境理论,采用分层贝叶斯模型,以当当网、京东、亚马逊和豆瓣网为数据搜集对象,在充分考虑网络口碑异质性及其来源多元化的条件下,结合外部网络口碑平台信息提供的特点,在进一步引入免费试样因素的基础上,对内外部网络口碑与在线销售的动态交互作用进行研究。结果发现:在异质性网络平台并存且效价差异较小的情境下,效价不再是影响在线销售的关键,而内部网络口碑数量、数量信息熵才是影响在线销售的关键,反过来在线销售也刺激了网络口碑数量的提升。虽然外部网络口碑的存在削弱了这一环形机制的积极影响,但免费试样可有效削弱该负向调节机制。     

分层教学中分层基础的确立——基于皮亚杰的认知发展阶段理论

分层教学是指将学生按照一定的分层基础分成不同的层次进行差别化教学的教学形式,通过分层教学可以更好的满足学生的个性化发展,让每个学生以自己最佳的学习状态完成学校要求的学习内容,但是以往的分层教学中的分层基础有很多的弊端,无论是班内分层还是混班分层虽然解决了部分问题,但是却带来了很多其他由于分层基础带来的学习问题。所以,通过借鉴皮亚杰的认知发展阶段理论,将其作为分层教学的分层基础依据,能够更好地适应学生身心发展条件,科学合理的将分层教学有效地运用与发展。     

基于分层模型的高校创业教育探析

创业教育作为21世纪现代人的第三本教育护照,已被国人认可和接受.但国内创业教育由于起步较晚,尚处于摸索阶段,因此,通过建立分层模型,进一步阐述创业教育的系统性.     

Confidence distributions applied to propagating uncertainty to inference based on estimating the local false discovery rate: A fiducial continuum from confidence sets to empirical Bayes set estimates as the number of comparisons increases

Empirical Bayes estimates of the local false discovery rate can reflect uncertainty about the estimated prior by supplementing their Bayesian posterior probabilities with confidence levels as posterior probabilities. This use of coherent fiducial inference with hierarchical models generates set estimators that propagate uncertainty to varying degrees. Some of the set estimates approach estimates from plug-in empirical Bayes methods for high numbers of comparisons and can come close to the usual confidence sets given a sufficiently low number of comparisons.