增长曲线模型中回归系数的线性估计的可容许性

对增长曲线模型,当协差阵是降秩的,在矩阵损失函数下,本文分别给出了回归系数的线性估计在非齐次线性估计类和全体估计类中是可容许估计的条件.     

Modeling the influences of upper-elementary school students’ digital reading literacy,socioeconomic factors,and self-regulated learning strategies

Background: Reading is an interactive and constructive process of making meaning by engaging a variety of materials and sources and by participating in reading communities at school or in daily life.

Aim: The purpose of this study was to explore the factors affecting digital reading literacy among upper-elementary school students.

Method: A 3-stage stratified cluster sampling was implemented that resulted in a sample of 592 upper-elementary students from 29 classes in 7 schools. Self-Regulated Learning Strategies Assessment (S-RLSA), Digital Reading Literacy Assessment (DRLA), and student reports of their parents’ education backgrounds were used to collect data on the outcome and predictor variables. Interpretation of these data involved two highly regarded statistical techniques. First, structural equation modeling was used to explore relationships amongst the constructs. Second, multi-group invariance (MI) analyses were used to assess the influence of parental education and self-regulated learning strategies on students’ digital reading literacy.

Results: Enriching students’ family learning resources and strengthening their self-regulated learning abilities could have very important influences on promoting upper-elementary school students' digital reading literacy -webpage information retrieval, reading and communication abilities.

Conclusions: This study also provides information on how teachers can address student resources to improve digital reading literacy and self-regulated strategies.     

Boundary control of a linear distributed parameter bioprocess

This paper is concerned with boundary control of a linear distributed parameter bioprocess. Huang's result (Ann. Differential Equations 1(1) (1985) 43) on the spectrum determined growth assumption is applied to prove that the closed-loop system becomes exponentially stable under a certain condition with respect to the feedback gain. Moreover, it is shown that the decay rate of the open-loop system is given by letting the feedback gain tend to zero.     

BIM在建设工程项目中的创新价值初探

对BIM国际前沿文献进行跟踪研究,梳理BIM在建设工程项目中的主要应用模式。在分析建设工程创新特性的基础上,指出BIM为建设工程项目各参与组织构建了合作创新的工作环境。依据建设工程创新类别,分析BIM应用模式的创新定位,探索BIM在建设工程创新中的价值。     

Undesirable economic growth via agents’ self-protection against environmental degradation

Our model analyzes the effects of the interplay between environmental degradation and consumption choices on economic growth dynamics and on economic agents’ welfare. We show that if private goods can be consumed as substitutes for environmental goods, then economic growth may be fueled by environmental deterioration. In this context, undesirable economic growth may occur, characterized by an inverse correlation between aggregate capital accumulation and economic agents’ welfare.     

唐山城乡居民消费对经济增长影响差异化的实证分析

作为多年来经济总量位居河北省第一位的唐山市,这几年国民经济得到了飞速发展,消费需求总量的逐步扩大在一定程度上对经济增长的拉动起到了举足轻重的作用。本文建立了城乡居民消费水平与唐山经济增长关系的误差修正模型,研究表明唐山城乡居民消费对其经济增长有正向拉动作用,城镇居民消费的拉动作用比农村居民的要大。因而,采取措施缩小城乡居民消费的差距,统筹二者的发展,是唐山完成两个"率先"的目标、建成全面小康社会不得不面对的问题。     

WTO与农民收入增长研究

本文通过定性分析和定量计算，找到影响农民收入增长的最重要因素；结合WTO《农业协议》及我国农业资源变化趋势和中国人口实际，提出逐步加大财政支农力度及区别对待；加强农业和农村经济发展的宏观调控，结合各地实际，分类指导；采取灵活的土地承包政策，实现土地规模经营，提高土地的产出率等一系列增加农民收入措施。     

Externalities, technological complementarities and sustained economic growth

Externalities as conventionally defined miss many of the spillovers that are both causes and consequences of the technological changes that underlie economic growth. We introduce a much wider concept called technological complementarities. New general purpose technologies (GPTs) rejuvenate the growth process by creating technological complementarities, which are adequately measured neither by total factor productivity (TFP) nor by externalities. There would be major gains from technological change even if the returns on capital invested in innovation never exceeded the returns on investing in existing technologies so that there were neither externalities nor positive changes in TFP.     

沉积微相约束条件下的随机地质建模方法及应用研究

以地质建模为主要研究对象,根据油田开发地质研究需要完善的方法技术,以建模方法研究为基础,进行了沉积微相约束地质建模综合研究.在分析目前国内外研究现状的基础上,针对我国开发地质研究工作的特点,提出根据测井解释成果,应用随机模拟的方法定量地开展沉积微相研究.应用沉积微相研究成果约束测井储层参数的分布,形成油藏数值模拟研究所需要的准确的储层三维地质模型,解决了常规油田开发地质研究过程中沉积相研究成果与储层参数分布无法有效结合的缺陷.应用与该方法相适应的IRMS软件成功实现了山东胜利油区孤东油田第七开发区西部上第三系馆陶组油藏精确的沉积微相模型,由此微相约束形成的油藏储层三维地质模型数据体直接应用于油藏数值模拟研究,应用效果及现场实施的效果良好.     

Application of machine learning techniques to assess the trends and alignment of the funded research output

Research and development activities are regarded as one of the most influencing factors of the future of a country. Large investments in research can yield a tremendous outcome in terms of a country’s overall wealth and strength. However, public financial resources of countries are often limited which calls for a wise and targeted investment. Scientific publications are considered as one of the main outputs of research investment. Although the general trend of scientific publications is increasing, a detailed analysis is required to monitor the research trends and assess whether they are in line with the top research priorities of the country. Such focused monitoring can shed light on scientific activities evolution as well as the formation of new research areas, thus helping governments to adjust priorities, if required. But monitoring the output of the funded research manually is not only very expensive and difficult, it is also subjective. Using structural topic models, in this paper we evaluated the trends in academic research performed by federally funded Canadian researchers during the time-frame of 2000–2018, covering more than 140,000 research publications. The proposed approach makes it possible to objectively and systematically monitor research projects, or any other set of documents related to research activities such as funding proposals, at large-scale. Our results confirm the accordance between the performed federally funded research projects and the top research priorities of Canada.