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.     

Restricted minimax estimation in semiparametric linear models

Abstract

In 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.     

Linguists and other animals

Book reviewed in this article:
Joan Dunayer, Animal Equality: Language and Liberation     

计算机与学术写作(英文)

深大外语系把若干计算机软件应用于英语专业本科学生的写作课教材系列。这不仅有助于学生自修写作技巧,且能为教师节省大量时间,使教师有可能对学生作更多的个别辅导。同时,学生在上写作课的过程中还能掌握一种使用计算机的实际技能。近十年来,中国的飞速发展是史无前例的。西方的技术发展史对中国虽然有启迪作用,但其实际要求与中国相去甚远。在这个意义上,深大的尝试对全中国均具有示范意义。     

复亚半正定矩阵

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。     

美国英语与美国人的时间观

语言作为文化的一部分，是文化的重要表达形式，透过一个民族的语言层面，可以窥见这个民族的文化形态。本文试图通过分析美国英语与时间有关的用语，来探讨美国人支配、利用时间的方式，以及时间这一无声的语言在美国文化中所蕴含的意义。     

外向/内向型性格对外语学习的影响

外向/内向型性格与外语学习有相关关系,通过实验证明外向型性格能对外语学习产生积极影响。     

清代蒙古族学堂教育及其语言教育

从 2 0世纪初开始 ,清朝教育制度发生了极大变化 ,出现了近代教育的萌芽。在这样一个大环境下 ,蒙古族近代学校教育的艰苦实践和探索也走上新的道路。蒙古族学堂教育是新教育思想的产物 ,虽然同旧的官学有一定的继承关系 ,但它打破封闭的传统教育 ,提倡开放的近代教育 ,由此教育种类和等级开始多样化、多层次化 ,出现普通教育、留学生教育和内地求学等形式。在学堂教育中 ,各种语言教育模式是同时并存的 ,这些模式经过分化和重组后 ,出现向汉语和蒙古语两个单语教育模式或蒙古语汉语双语教育模式集中的倾向。     

凉山彝语ABAB式形容词研究

凉山彝语中有一种特殊的ABAB式四音格形容词 ,以往的教科书和字词典都忽视不收 ,在日常生活中其使用频率较高。在语义表达上与现代汉语ABAB式形容词较为相似 ,但不完全相同。其产生有两种基本形式。在语音结构和语用上不同于描摹词 ,在句中充当状语和定语等句子成分。     

从量词看苗汉两种语言的关系

“名物量词”在各种语言中的产生、发展规律不尽一致。因此 ,透过“名物量词”探查两种语言的源流 ,不失为一条可行的途径。从苗汉两种语言量词的统计材料中 ,可以看到两种语言量词的兴起和发展过程。湘西苗语的量词与同时代汉语的量词相比 ,在数量上没有汉语的多 ,在范围上没有汉语的宽。各个历史时期 ,湘西苗语都从汉语借用一批词语 ,相应的汉语量词就跟着进入苗语了。从量词的起源和发展来看 ,苗语深受汉语的影响 ,但是很难说苗汉两种语言出于同一母语。