Analytic evaluation of the expectation and variance of different performance measures of a schedule on a single machine under processing time variability

In this paper, we present closed-form expressions, wherever possible, or devise algorithms otherwise, to determine the expectation and variance of a given schedule on a single machine. We consider a variety of completion time and due date-based objectives. The randomness in the scheduling process is due to variable processing times with known means and variances of jobs and, in some cases, a known underlying processing time distribution. The results that we present in this paper can enable evaluation of a schedule in terms of both the expectation and variance of a performance measure considered, and thereby, aid in obtaining a stable schedule. Additionally, the expressions and algorithms that are presented, can be incorporated in existing scheduling algorithms in order to determine expectation-variance efficient schedules.     

国内60年机器翻译研究探索——基于外语类核心期刊的分析

机器翻译近年来受到国内译学界的普遍关注。以CNKI收录的12种外语类核心期刊为数据来源,以量化统计结合质性分析的方法,对60年来国内译学界探索机器翻译研究的历程进行了梳理与分析。研究发现：（1）机器翻译研究总体态势呈四个阶段：1950s的萌芽期,1960s-1970s的停滞期,1980s-1990s的缓慢发展期和2000年以后的快速发展期;（2）研究主题主要含语义研究,人机翻译质量对比分析和翻译人才培养等;（3）研究学者之间、学科之间合作亟待加强。该研究为梳理我国译学界探索机器翻译研究的历程提供了参考。     

心理模块性与句法加工

模块性理论为心理学和语言学的研究提供了新的思路和研究方法,促进了认知科学的发展。从乔姆斯基提出模块性理论到福多的心理模块性,模块性理论逐渐走向成熟。模块论者把心理和图灵机进行类比,认为心理本质上是符号操纵装置,认知运算是依据句法结构进行的。通过与图灵机原理进行类比,对句法加工的特点进行分析,得出句法加工是模块性的。     

基于SVM的核电装备制造业供应风险预测模型研究

基于对核电装备制造业供应风险的因素识别,确立风险预测指标体系;对国内某家重点核电装备制造企业及其60家供应商进行问卷调研及深度访谈,运用支持向量机及libsvm技术建立供应风险的预测模型;最后的案例研究表明了该预测体系的可行性与可靠性。     

中国现代科技史上的一起重要事件--记20世纪60年代关于"积木式机床"的讨论

20世纪60年代初,哈尔滨工业大学部分教师所写的一篇文章,引起了当时的中共中央主席毛泽东的注意,他破例以<红旗>杂志编辑部的名义给作者写了一封亲笔信索稿.哈尔滨工业大学部分教师又写了一篇长文在<红旗>上刊出.由此,在中国机械工程界引发了一场热烈的讨论,产生了巨大的影响.这一事件说明国家领导人的态度,决定了国家的政策,也关系到许多重要问题.     

液压设备的固体污染分析及防治措施

液压系统中的固态杂质,是污染油液的主要原因,也是液压泵和液压马达效率降低,液压阀卡死,噪声和振动等现象发生的主要原因。因此,固体污染物分析与控制的研究具有积极而重要的意义。     

决策支持系统中的建模知识表示研究

提出一种基于知识的建模支持系统 ,该系统的知识由三部分组成 :构模规则知识、变量类型知识以及数据映射知识 .构模规则知识描述了决策者的构模过程 ;变量类型知识定义了构模规则知识中所有变量的数据类型 ;数据映射知识描述求解过程所需数据的来源 .对于决策者输入的一个实际决策问题 ,系统能够根据问题描述按照构模知识自动进行求解 ,同时对经验进行学习 ,生成经验规则     

机器翻译中多义词的消歧

鉴于自然语言语序的灵活性,使得自然语言知识的自动消歧很困难。提出一种机器翻译中多义词词义消歧的新方法,从语境相关素的角度着手,把人类消歧时进行的逻辑推理归结为一种便于机器操作的机械的集合运算,提高了消歧的准确率。     

Predicting online gambling self-exclusion: an analysis of the performance of supervised machine learning models

As gambling operators become increasingly sophisticated in their analysis of individual gambling behaviour, this study evaluates the potential for using machine learning techniques to identify individuals who used self-exclusion tools out of a sample of 845 online gamblers, based on analysing trends in their gambling behaviour. Being able to identify other gamblers whose behaviour is similar to those who decided to use self-exclusion tools could, for instance, be used to share responsible gaming messages or other information that aids self-aware gambling and reduces the risk of adverse outcomes. However, operators need to understand how accurate models can be and which techniques work well. The purpose of the article is to identify the most accurate technique out of four highly diverse techniques and to discuss how to deal analytically and practically with a rare event like self-exclusion, which was used by fewer than 1% of gamblers in our data-set. We conclude that balanced training data-sets are necessary for creating effective models and that, on our data-set, the most effective method is the random forest technique which achieves an accuracy improvement of 35 percentage points versus baseline estimates.