Automating argument construction

Over the past five years the Artificial Intelligence Center at SRI has been developing a new technology to address the problem of automated information management within real- world contexts. The result of this work is a body of techniques for automated reasoning from evidence that we call evidential reasoning. The techniques are based upon the mathematics of belief functions developed by Dempster and Shafer and have been successfully applied to a variety of problems including computer vision, multisensor integration, and intelligence analysis.

We have developed both a formal basis and a framework for implementating automated reasoning systems based upon these techniques. Both the formal and practical approach can be divided into four parts: (1) specifying a set of distinct propositional spaces, (2) specifying the interrelationships among these spaces, (3) representing bodies of evidence as belief distributions, and (4) establishing paths of the bodies for evidence to move through these spaces by means of evidential operations, eventually converging on spaces where the target questions can be answered. These steps specify a means for arguing from multiple bodies of evidence toward a particular (probabilistic) conclusion. Argument construction is the process by which such evidential analyses are constructed and is the analogue of constructing proof trees in a logical context.

This technology features the ability to reason from uncertain, incomplete, and occasionally inaccurate information based upon seven evidential operations: fusion, discounting, translation, projection, summarization, interpretation, and gisting. These operation are theoretically sound but have intuitive appeal as well.

In implementing this formal approach, we have found that evidential arguments can be represented as graphs. To support the construction, modification, and interrogation of evidential arguments, we have developed Gister. Gister provides an interactive, menu-driven, graphical interface that allows these graphical structures to be easily manipulated.

Our goal is to provide effective automated aids to domain experts for argument construction. Gister represents our first attempt at such an aid.     

成都将军的设置及其在治理川西藏区中的作用

清乾隆年间对大小金川土司的用兵结束后,为了加强对康藏及川西藏族的统治,乾隆帝特设成都将军,统辖八旗和绿营,治理川边。成都将军在维护川西藏族地区的稳定、保持川藏大道的畅通、巩固西南边疆的安全等方面均起到了积极的作用。     

被动语态在外贸函电中的应用及其语用功能

本文贸函电为例,从语用学的角度分析,被动语态有很多独特的语用功能。     

信息内容可信度对消费者转基因食品接受程度的影响——以江苏省为例

深入研究外部信息传入特别是信息内容可信度对消费者转基因食品接受程度的影响对中国政府转基因科普宣传具有重要意义。利用江苏省消费者调查数据,定量研究信息内容可信度等因素对消费者转基因食品接受程度的影响,具体来说,定量研究积极属性信息内容和消极属性信息内容对不同风险人群(所有样本、低风险人群、高风险人群)转基因食品接受程度的影响。研究结果表明,外部信息传入更容易影响低风险人群对转基因食品的接受程度。积极属性和消极属性信息内容可信度分别显著正向和负向影响低风险人群对转基因食品的接受程度,且前者的作用较大。积极属性信息内容可信度对高风险人群转基因食品接受程度的影响较弱,而消极属性信息内容可信度对高风险人群几乎没有影响。     

A Bayesian sequential design with binary outcome

Several researchers have proposed solutions to control type I error rate in sequential designs. The use of Bayesian sequential design becomes more common; however, these designs are subject to inflation of the type I error rate. We propose a Bayesian sequential design for binary outcome using an alpha‐spending function to control the overall type I error rate. Algorithms are presented for calculating critical values and power for the proposed designs. We also propose a new stopping rule for futility. Sensitivity analysis is implemented for assessing the effects of varying the parameters of the prior distribution and maximum total sample size on critical values. Alpha‐spending functions are compared using power and actual sample size through simulations. Further simulations show that, when total sample size is fixed, the proposed design has greater power than the traditional Bayesian sequential design, which sets equal stopping bounds at all interim analyses. We also find that the proposed design with the new stopping for futility rule results in greater power and can stop earlier with a smaller actual sample size, compared with the traditional stopping rule for futility when all other conditions are held constant. Finally, we apply the proposed method to a real data set and compare the results with traditional designs.     

非言语交际与外语教学

非言语交际作为言语交际的重要组成部分,在外语教学中,起着不可忽视的作用。恰当地使用非言语交际行为,能够创建良好的师生关系,提高学生学习兴趣。本文分析了非言语交际行为的重要性及其在外语课堂教学中的表现形式和作用。     

我国新型农民合作社的形态、功能及其发展

按照性质不同,我国的农民合作社可划分为新型农民合作社和传统农民合作社两大类型.新型农民合作社的基本功能是农户间的团结协作和互利互惠,它有利于促进农业产业化经营;抵御农业经营风险;实现农民共同富裕;推进农村民主政治建设.从我国的情况看,在发达国家农业产业化经营的三种模式--综合型模式、合同型模式和合作社型模式中,合作社型模式更适合我国的农业产业化经营.由于当前在发展新型农民合作社中存在的,诸如合作的认识不够明确、合作的环境不够优良、合作的机制不够完善的问题,这需要通过教育普及国际公认的合作经济理论和实务知识;尽快出台<农村资金合作社法>,明确各类农民合作社的主管部门;建立、健全合作社"三会"制度及议事规则.     

Use of log−log survival function in modeling time-covariate interactions in Cox regression

Plotting of log−log survival functions against time for different categories or combinations of categories of covariates is perhaps the easiest and most commonly used graphical tool for checking proportional hazards (PH) assumption. One problem in the utilization of the technique is that the covariates need to be categorical or made categorical through appropriate grouping of the continuous covariates. Subjectivity in the decision making on the basis of eye-judgment of the plots and frequent inconclusiveness arising in situations where the number of categories and/or covariates gets larger are among other limitations of this technique. This paper proposes a non-graphical (numerical) test of the PH assumption that makes use of log−log survival function. The test enables checking proportionality for categorical as well as continuous covariates and overcomes the other limitations of the graphical method. Observed power and size of the test are compared to some other tests of its kind through simulation experiments. Simulations demonstrate that the proposed test is more powerful than some of the most sensitive tests in the literature in a wide range of survival situations. An example of the test is given using the widely used gastric cancer data.     

Substance‐dependent women becoming mothers: breaking the cycle of adverse childhood experiences

Parenting may be particularly challenging for substance‐dependent mothers who have grown up with parents who themselves had substance use disorders (SUDs). The aim of this study was to explore how substance‐dependent mothers describe their childhood experiences with substance‐abusing parents and the association between these earlier experiences and their own role as caregivers. Using purposeful sampling, mothers admitted for 1 year to a family ward at a substance abuse clinic were approached. Through in‐depth, qualitative interviews, nine substance‐dependent mothers described their lives in the form of present, past and future tense. The findings indicate that substance‐dependent women, who have experienced SUDs in their families of origin, face several major challenges when they become mothers. Some describe having lived their whole lives ‘on the edge of society'. This makes their rehabilitation process more complex. All mothers work to abstain from substances, process traumatic experiences and integrate their family into society. They need help to build supportive social networks and to establish a safe and predictable family environment for themselves and their children. The therapeutic implications of these findings will be discussed.     

Applying a Positive Youth Development Perspective to Observation of Bereavement Camps for Children and Adolescents

A positive youth development perspective focuses on recognizing psychosocial strengths and providing social environments that contribute to the development of these in children and adolescents. Bereavement camps can provide such an environment as they help children cope with the death of someone close. The purpose of this study was to observe bereavement camps through the lens of positive youth development to determine the applicability of the eight features of positive developmental settings for describing bereavement camps (safety, appropriate structure, supportive relationships, opportunities to belong, positive norms, support for efficacy, skill building opportunities, integration of family and community). Observational notes were recorded by researchers during on-site visits to three different weekend bereavement camps. Results identified how each element of positive developmental settings was exemplified in either typical camp activities or bereavement-focused activities. For example, assigning campers to cabin groups based on age and gender provided opportunities to belong, and giving campers a comfort object and a big buddy provided supportive relationships. Findings were used to create a positive developmental settings observation checklist for use by bereavement camp practitioners to assess the extent to which each camp provides the requisite elements for promoting positive youth development.