四川地区农民持续增收的制约因素分析

根据四川省统计局的历年数据,本文分析了四川省农民收入增长的规律：改革来,四川农民收入总量上呈现逐年增长、增幅减缓的特征;四川农民收入水平在全国的排位下降。宏观经济分析表明,影响农民收入持续增长的主要有外部因素如制度障碍、农业投入不足、农资价格上涨等,内部因素如生产结构不合理、基础设施脆弱和农民素质不高等方面。因此,要构建农民增收的长效机制必须突破制度障碍。     

Estimation of Hazard, Density and Survivor Functions for Randomly Censored Data

Maximum likelihood estimation and goodness-of-fit techniques are used within a competing risks framework to obtain maximum likelihood estimates of hazard, density, and survivor functions for randomly right-censored variables. Goodness-of- fit techniques are used to fit distributions to the crude lifetimes, which are used to obtain an estimate of the hazard function, which, in turn, is used to construct the survivor and density functions of the net lifetime of the variable of interest. If only one of the crude lifetimes can be adequately characterized by a parametric model, then semi-parametric estimates may be obtained using a maximum likelihood estimate of one crude lifetime and the empirical distribution function of the other. Simulation studies show that the survivor function estimates from crude lifetimes compare favourably with those given by the product-limit estimator when crude lifetimes are chosen correctly. Other advantages are discussed.     

Uncertainty Analysis for Computer Model Projections of Hurricane Losses

Projecting losses associated with hurricanes is a complex and difficult undertaking that is wrought with uncertainties. Hurricane Charley, which struck southwest Florida on August 13, 2004, illustrates the uncertainty of forecasting damages from these storms. Due to shifts in the track and the rapid intensification of the storm, real-time estimates grew from 2 to 3 billion dollars in losses late on August 12 to a peak of 50 billion dollars for a brief time as the storm appeared to be headed for the Tampa Bay area. The storm hit the resort areas of Charlotte Harbor near Punta Gorda and then went on to Orlando in the central part of the state, with early poststorm estimates converging on a damage estimate in the 28 to 31 billion dollars range. Comparable damage to central Florida had not been seen since Hurricane Donna in 1960. The Florida Commission on Hurricane Loss Projection Methodology (FCHLPM) has recognized the role of computer models in projecting losses from hurricanes. The FCHLPM established a professional team to perform onsite (confidential) audits of computer models developed by several different companies in the United States that seek to have their models approved for use in insurance rate filings in Florida. The team's members represent the fields of actuarial science, computer science, meteorology, statistics, and wind and structural engineering. An important part of the auditing process requires uncertainty and sensitivity analyses to be performed with the applicant's proprietary model. To influence future such analyses, an uncertainty and sensitivity analysis has been completed for loss projections arising from use of a Holland B parameter hurricane wind field model. Uncertainty analysis quantifies the expected percentage reduction in the uncertainty of wind speed and loss that is attributable to each of the input variables.     

Statistik für bivariate gemischte Poisson–Prozesse am Beispiel der Kraftfahrthaftpflichtversicherung

Zusammenfassung: In diesem Artikel wird der Weg von einem univariaten gemischten Poisson–Prozess, der in vielen Bereichen zum Z?hlen von Ereignissen benutzt wird, zu einem bivariaten gemischten Poisson–Prozess aufgezeigt. Dazu werden einige Eigenschaften des bivariaten Prozesses angegeben. Im zweiten Teil der Arbeit wird gezeigt, wie mit Hilfe dieses Prozesses der übergang von einem herk?mmlichen Bonus–Malus–System in der Kraftfahrthaftpflichtversicherung zu einem Bonus–Malus–System mit Berücksichtigung der Schadenart beschritten werden kann. Dazu wird zuerst eine Modellprüfung der gegebenen Daten vorgenommen und sodann werden für verschiedene mischende Verteilungen die Verteilungsparameter gesch?tzt und Nettopr?mien angegeben sowie die Prognosegenauigkeit getestet.

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Summary: In this paper we show that the model of the bivariate mixed Poisson process arises in a natural way from the univariate mixed Poisson process, which is used in several areas for counting certain events. Furthermore we state some properties of the bivariate process. In the second part of the paper we illustrate how by means of the bivariate mixed Poisson process a bonus–malus system handling different types of accidents can be derived from the classical bonus–malus system in third–party liability insurance. To this end we first check the model on the given data and then estimate distribution parameters and compute net premiums for different mixing distributions as well as test the prediction probabilities.

* Vortrag am Dresdner Forum zur Versicherungsmathematik: Tarifierung in Erst- und Rückversicherung am 25. Juni 2004. Für die Unterstützung zu dieser Arbeit m?chte der Autor Lothar Partzsch, Klaus D. Schmidt (beide Dresden) und Friedemann Spies (München) recht herzlich danken.     

从网络小说看网络文学基本特征

网络文学已登上二十一世纪中国文学的大雅之堂。从最能体现网络文学基本特征的网络小说进行探析 ,认为网络文学的基本特征为 :情感表达的宣泄性 ;著读交流的迅捷性 ;叙事结构的随意性 ;语言表达的能动性等。     

电子商务在煤炭贸易中的应用

电子商务是对整个贸易活动实现电子化 ,具有营运成本低、用户范围广、无时空限制以及能同用户直接互动交流等特点 ,代表着未来贸易发展的方向。电子商务在化工、家电、IT等商品流通领域已得到充分利用 ,而在我国的煤炭销售方面还没有专业性网站。建立专业的煤炭贸易电子商务网站对促进煤炭销售市场规范化、加速煤炭工业的可持续发展有重大意义。本文以中国煤炭贸易电子商务网站 (WWW .JCLC ,COM .CN)建设为例介绍了电子商务在煤炭贸易中的应用     

用Chat Anywhere工具架构局域网内的聊天室

以如何应用ChatAnywhere工具来实现建立一种架设内网聊天服务器的简单方法。     

基于串行通信的双Web服务器冗余系统设计与实现

设计实现了一个基于串行口通信的双Web服务器的冗余系统,详细介绍了基于串行通信口的实现方法,并对冗余系统的原理和实现过程进行了分析。     

基于校园网的三层结构网络教学平台构建

网络教学平台是实现网络教学的基础。传统的两层结构应用模式具有一定的局限性,采用Web数据库技术和动态网页设计技术构建基于校园网的三层结构网络教学平台,能有效的解决网络传输流量等方面的问题,能更好的在校园网上实现教学资源的共享,提高网络教学的质量。     

信息技术与中外语教学

本文从七个方面探讨了信息技术对中外语教学的变革,并从四个方面对政府和高校的教学管理部门提出适应变革的建议。