雷诺校正法在煤发热量测定中的应用

介绍雷诺校正法计算煤发热量的原理、算法及应用.方法应用于燃煤发热量计算,结果表明,用雷诺校正法处理煤发热量测定时,其结果优于瑞方公式法和奔特公式法,与国标法相比,分析误差在规定范围内.在文中列出了雷诺校正法处理煤发热量的实用Matlab源程序.     

Guiding Data Analysts with Visual Statistical Strategies

Abstract

The concept of statistical strategy is introduced and used to develop a structured graphical user interface for guiding data analysis. The interface visually represents statistical strategies that are designed by expert data analysts to guide novices. The representation is an abstraction of the expert's concepts of the essence of a data analysis. We argue that an environment that visually guides and structures data analysis will improve data analysis productivity, accuracy, accessibility, and satisfaction in comparison to an environment without such aids, especially for novice data analysts. Our concepts are based on notions from cognitive science, and can be empirically evaluated. The interface consists of two interacting windows—the guidemap and the workmap. Each window contains a graph that has nodes and edges. The guidemap graph represents the statistical strategy for a specific statistical task (such as describing data). Nodes represent potential data analysis actions that can be taken by the system. Edges represent potential actions that can be taken by the analyst. The guidemap graph exists prior to the data analysis session, having been created by an expert. The workmap graph represents the complete history of all steps taken by the data analyst. It is constructed during the data analysis session as a result of the analyst's actions. Workmap nodes represent data sets, data models, or data analysis procedures that have been created or used by the analyst. Workmap edges represent the chronological sequence of the analyst's actions. One workmap node is highlighted to indicate which statistical object is the focus of the strategy. We illustrate our concepts with ViSta, the Visual Statistics system that we have developed.     

注重基础促进交叉尊重选择培育英才 ——北京大学化学学科"拔尖计划"十年

北京大学化学与分子工程学院在实施基础学科拔尖学生培养计划过程中,实行动态管理制度,低年级统一培养,高年级通过制定个性化教学方案和参加科研训练的办法遴选拔尖学生,探索"扎根课堂打好基础,依托科研提高能力,着眼交流开阔眼界"的培养模式,实现"以高水平科研带动创新人才培养"的目标。在基础核心课程中设置平行的英文班和阅读讨论班以适应不同学生的需求。2016年,随着北京大学综合改革计划的推进,进一步明确了"一体化、多层次、开放式、重基础、求创新"的教学指导思想,在注重化学基础理论知识和基本实验方法培养、注重数学和物理基础知识学习的基础上,构建多样化和多模式的立体课程体系,为学生提供适合的课程学习和个性化学术发展途径。     

A study of repetitive news display and news consumption in Korea

The shift to online news consumption has weakened the direct relationship between readers and news publishers. News publishers now depend on the number of clicks and comments on their news to increase their revenues. Repetitive news display or news abusing is used extensively by Korean news publishers to draw consumers’ attention to their content. This study examines the factors causing news abusing in Korea. We analyze the factors that affect both news abusing frequency and intensity, and examine how they vary in both intra-media and inter-media contexts. We empirically test the relationship between the number of clicks (comments on the news posted) and the abusing frequency of the news article (abusing intensity of the news article). Finally, we try to identify the differences in the relationships between the effects of news abusing and the number of clicks and comments based on news abusing patterns and news article types.     

Are female users equally active? An empirical study of the gender imbalance in Korean online news commenting

Because online news is pervasive and online comments provide space for people to express their opinions and participate in open discussions, they affect public opinion. However, at least in Korea, male users seem not only to be more active in consuming online news but also in commenting online. Many previous studies have investigated the gender imbalance in news consumption of not only traditional media but also online media. Although a few studies explored gender differences in online comments on news, no study has investigated such gender differences using actual data on the basic profiles of commenters. To fill the gap between previous studies and reality and address the gender imbalance in online news comments and public opinion, this study examined the differences between male and female online news commenters. Furthermore, using actual data provided by Naver, the dominant Internet portal in Korea, this study analyzed the characteristics of female news commenters and those of news content where female users most actively commented. This study found that—at least in Korea—fewer women comment on news, they are less active than men, and that there is a difference between younger and older women. This study also found that people write more comments in a day as their age increases and the gender differences decrease with age.     

The Social News Gap: How News Reading and News Sharing Diverge

This article seeks to explain variation in news sharing patterns on social media. It finds that news editors have considerable power to shape the social media agenda through the use of “story importance cues” but also shows that there are some areas of news reporting (such as those related to crime and disasters) where this power does not apply. This highlights the existence of a social “news gap” where social media filters out certain types of news, producing a social media news agenda which has important differences from its traditional counterpart. The discussion suggests that this may be consequential for perceptions of crime and engagement with politics; it might even stimulate a partial reversal of the tabloidization of news outlets.     

相位交替组合脉冲NMR

用Wigner旋转矩阵和修改的Levenberg-Marquardt算法来描述优选相位交替组合π脉冲,编写了子程序DBCLSF和QRDCMP代表"IMSL"子程序库,解决非线性最小二乘法的问题.计算是在COMPAQ 586PC机上进行.可以发现,其优化结果同参考文献中用IBM/3600大型计算机的结果相同,优于其它现有的组合π脉冲.     

The Z specification dependence graph

The lack of existing solutions makes it really hard to understand formal specification languages since the application domain for representations is useful for the purpose of carrying out certain software engineering operations such as slicing and the computation of program metrics.A Z specification dependence graph is presented in this letter. It draws on the strengths of a range of earlier works and adapts them, if necessary, to the Z language.     

数字电视EMC测试用码流信号的配制

目前数字电视系统技术,测试标准以及测试设备还不够完善.本文对数字电视测试码流信号的进行研究,配制了一组适合EMC测试的码流信号,解决了数字电视EMC测试用码流信号难题.     

用可编程器件实现ISD4004级联工作设计

分析了ISD（Information Storage Device）4004芯片的录放音控制方法,用ISP（In-System Programmable digital Circuits）在系统编程器件M4-32／32实现了对4片ISD4004语音芯片的录放音控制设计,使录放时间达64min。与其它控制方法相比是一种新方法。