Mixture models and atypical values

The resolution of a mixture of two or more populations into its component distributions may be markedly influenced by one or a few atypical values. The maximum likelihood solution effectively assigns (part of) each observation to one or another of the components via the posterior probabilities, even though the observation may be widely discrepant from all components. This paper presents a modification of the mixture problem, in which the typicality of each observation is considered, as well as the posterior probabilities, with the contribution of atypical observations being downweighted. The extension to the multivariate case is discussed.     

A Teacher's Introduction To Remote Sensing

Abstract

This article is an introduction to remote sensing. It provides the novice with a definition of remote sensing, information about some remote sensing products, data that can be obtained from remote sensing images, what can be done with images, ideas to integrate remote sensing with other subjects, a sample unit using images, and a list of associate areas related to remote sensing. The article also contains information for obtaining remote sensing materials and information and considers values concerns relating to remote sensing.     

Public opinions on biological diversity in Norway: Politics,science, or culture?

Loss of biological diversity is among the most pressing environmental problems facing modern societies. Whereas today much is known about peoples' opinions on climate change, there is still a lack of knowledge regarding how people asses the issue of biological diversity. The article represents a step towards a better understanding of public opinions on the issue of biodiversity, and hence also of the prerequisites and possibilities for a more or less vigorous or legitimate policy on this issue. The analyses show that social background matters for concern about biodiversity, but only to a certain extent: women are less negative towards biodiversity protection than men, the older segments of the population, at least in Norway, are less concerned with biodiversity, and education has only a marginal effect. Hence, to a large extent, political attitudes matter and indicate that concern for biodiversity seems to work by various types of available heuristics whereby a given case is linked to political understandings of other and similar and/or familiar issues. The inclusion of other political variables (local decision-making) and what the authors label ‘cultural variables’ (e.g. view of nature and trust in science) seem also to matter decisively for attitudes towards biodiversity.     

回归分析在确定多金属硫化物矿石密度中的应用

在研究多金属硫化物矿床的特点,分析以往矿床勘查中确定矿石密度值难点的基础上,通过建立矿石密度值与矿石各组分的多元线性回归数学模型,预测矿床的矿石密度值。     

Protecting Important Agricultural Heritage Systems (IAHS) by Industrial Integration Development (IID): Practices from China

With Globally Important Agricultural Heritage Systems (GIAHS) increasing in number around the world, their conservation has become a new international research theme. From the perspective of combining theoretical analyses and practical case applications, this study examines the Important Agricultural Heritage Systems (IAHS) conservation pathways and operation mechanisms through industrial integration development (IID). First, the theoretical framework of IID in IAHS sites was constructed according to the requirements of IAHS conservation, which include analyses of the connotation and basic principles of IID, the necessity of IID for IAHS sites, the resource conditions, and the IID pathways. And then based on the theoretical framework, the IID of Longji Terraces in Guangxi, Honghe Hani Rice Terraces System in Yunnan (HHRTS), Aohan Dryland Farming System in Inner Mongolia (ADFS), and Huzhou Mulberry-dyke & Fish-pond System (HMFS) in Zhejiang are analyzed systematically. The main finding is that IID is an effective pathway for IAHS conservation. However, the IID in IAHS sites must stress the ecological and cultural values of the resources; IID should be based on local resource advantages; and IID should attach importance to the combination of different policies and coordination between different stakeholders.     

滇东北山区坡耕地土壤侵蚀的地形因子

通过在滇东北山区坡耕地上设置１８个不同坡度和坡长的试验小区,并进行连续３年实测,得到本区域土壤侵蚀地形因子（ＬＳ）的定量关系式,据此求得滇东北山区坡耕地土壤侵蚀的坡面地形效应（ＬＳ值）表。     

The Most Geomagnetically Disturbed 24 Hours

Geomagnetically disturbed periods, characterized by the maximum average 24-hour global disturbances are considered. Gumbel's first asymptotic distribution of extreme values is used to predict the occurrence of major magnetic storm periods. A geomagnetic storm similar to the one recorded on March 13 - 14, 1998, would be expected to occur within the next 13 solar cycles. The present analysis corroborates the substantial increase of the level of magnetic disturbances from solar cycle to solar cycle.     

复合桩基水泥土非线性应力-应变关系模型

在不同区域采集相关样品,根据不同水泥掺合比及护龄期不同,采用几种不同围压分别进行水泥土三轴压缩试验,通过试验结果得到应力一应变曲线,提出一个具有峰值后下降并趋于某定值性质的分段连续函数,并以该分段连续函数表示水泥土的力学模型。     

Food and energy in the diet of brown and rainbow trout from Lake Benmore,New Zealand

The diet of brown trout (Salmo trutta) and rainbow trout (S. gairdnerii) was studied in specimens from Lake Benmore, a deep, oligo‐trophic lake in South Island, New Zealand. Between November and July, both species fed mainly on small molluscs (Potamopyrgus antipodarum, Physa sp., and Gyraulus corinna) gleaned from the littoral weed beds. Energy values for the three species of mollusc were determined: P. antipodarum, 6000 J g^‐1; G. corinna, 5500 J g^‐1; Physa sp., 9800 J g^‐1. Potamopyrgus antipodarum yielded little energy to the fish, unless its shell broke during passage through the gut. Physa sp. was the most profitable mollusc, irrespective of shell breakage and Potamopyrgus antipodanim the least profitable. The mean energy value per snail for G. corinna and Physa sp. eaten by rainbow trout was 25–30% less than for snails eaten by brown trout, possibly because rainbow trout ingested empty shells from the sediment surface. Rainbow trout extracted about 20% more energy than brown trout from unbroken shells. In July, 84% of the brown trout switched to predation of common bullies, Gobio‐morphus cotidianus, probably as a result of bully reproductive behaviour. Rainbow trout did not show the same change, apparently because they were feeding in deeper water where few bullies were available. The low‐energy diet and its possible connection with growth rate are discussed.     

亚纯函数微分多项式的一个正规定则

证明了下面两个定理：（1）设n,k≥2为正整数,a为有穷非零复数,F为区域D上的亚纯函数族,F中任一函数的零点重级至少为k．vf,g∈F,fLn（f）与gLn（g）IM分担a．则F在D上正规,其中L（f）为f（k）＋a1f^（k-1）＋…＋akf,这里a1,…,ak为常数．（2）设n,k为正整数,且n≥2,a为有穷非零复数,F为区域D上的亚纯函数族,F中任一函数的零点重级至少为k,且fLn（f（z））=a能够推出｜f^（k）（z）｜≤A,其中A为正数,则F在区域D上正规．