再生骨料混凝土的工程应用现状和基本性能分析

本文分析国内外再生混凝土在工程中的应用现状,通过对再生混凝土研究的进展和成果进行分析,总结了再生骨料混凝土基本力学性能、耐久性、工作性的特点,并提出了改善这些性能的方法。     

Using crowdsourcing for TREC relevance assessment

Crowdsourcing has recently gained a lot of attention as a tool for conducting different kinds of relevance evaluations. At a very high level, crowdsourcing describes outsourcing of tasks to a large group of people instead of assigning such tasks to an in-house employee. This crowdsourcing approach makes possible to conduct information retrieval experiments extremely fast, with good results at a low cost.     

Do you see what I see? A social capital perspective on microtask gig worker opportunity recognition within electronic networks of practice

Microtask gig workers (MGWs) rely on digital platforms to arrange work agreements with requesters to complete well-defined microtasks. Many MGWs use an electronic network of practice (ENP) to facilitate information sharing about desirable and undesirable microtasks. This study uses social capital theory to theorize how social capital’s dimensions – structural, cognitive, and relational – shape the development of uncertainty-reducing and individualized-skill benefits. Based on survey data from 436 Amazon Mechanical Turk (MTurk) workers, the findings demonstrate that unique social capital dimensions affect specific ENP benefits. Understanding the communication style of an ENP (i.e., cognitive social capital) positively influences the uncertainty-reducing benefits of microtask information quality (MIQ) related to MTurk work. Combined with expectations of reciprocity and trust in ENP members (i.e., relational social capital), MIQ shapes microtask opportunity recognition (MOR), whereby individual MGWs identify opportunities to complete financially beneficial microtasks. The present study demonstrates that contextual factors, based on the coopetive nature of microtask ENPs, affect the interrelated structure of social capital theory and its underlying dimensions. Lastly, post hoc findings demonstrate the influence of MOR on MGWs’ financial performance, challenging previously held assumptions about the role of MIQ within the microtask literature.     

论数控技术与机制专业的教改关系

本文简要分析了我国机械制造业当今面临的主要问题.对数控技术在高校机制专业教学改革中所起的作用和必然性进行了探讨.论述了机械制造业的发展方向、建立先进制造系统以及机制专业培养人才必须与之适应的关系,数控技术作为先进制造系统的基础而应在教改中加强教育的模式、途径和方法.     

地形测量普及型直角坐标展点尺的设计与应用

设计了一种地形测量直角坐标展点尺,介绍了它的使用方法．该尺具有灵活方便、快速、准确等优点,便于普及应用．     

数据压缩技术及其在计算机图像和计算机图形方面的应用

本文简要介绍了数据压缩的标准、种类、原理和算法,在各种文件格式的计算机图形和计算机图像中的应用。     

从抛体运动的研究看力学的发展

抛体运动是力学研究的一部分,历史上不少学者都贡献过自己不同的观点和看法,其中伽利略做了最为系统和认真的研究,从此力学科学发生了质的飞跃。文章通过对历史上抛体运动研究这一具体事例的梳理,归纳了不同时期的研究现状,分析出新旧理论之间的相关性、继承性和突破性,从而提出抛体运动的历史研究从一个侧面反映出自然科学的发展是积累与充实、继承与革命的辩证统一。     

Tears for girls and teeth for boys: the influence of gender on children’s depiction of sadness and anger in their drawings

Up to now, very few studies investigated the influence of gender on the depiction of emotions in children’s drawings. However, the literature on emotions reveals differences between boys and girls in various kinds of tasks (e.g. recognising emotional facial expressions, understanding an emotional situation, etc.). Therefore, we examined the impact of gender on the depiction of sadness and anger. We took into account children’s gender but also the gender of the character expressing the target emotion. Forty-four boys and forty-seven girls aged 7–8 and thirty-six boys and fifty-three girls aged 9–10 were asked to listen to stories where the main character (either a male or a female) was feeling sad or angry and then to draw the facial cues corresponding to the target emotion. Two methods were used to rate the drawings: judges assessed the correct vs. incorrect depiction of the two target emotions and a content analysis was then conducted on the correct drawings so as to reveal the type of facial cues used by children. By showing the major influence of children’s gender on their depiction of sadness and anger, our findings offer promising lines of research in educational and clinical settings.     

浅谈中职学生建筑制图与识图课程学习兴趣的培养

建筑制图与识图课程是中职学校建筑专业最重要的一门专业知识课,它的教学目标是培养学生学习绘制和阅读工程图样,训练学生的制图技能和空间想象力,为学生学习其他相关专业课程打下基础。由于,该课程的学习难度较大,许多学生缺乏学习兴趣,使得该课程的教学有一定的难度。本文拟从日常教学中培养学生的学习兴趣入手,提出了一些切实可行的教学方法,与教育同行一起探讨中职学生的建筑制图与识图学习问题。     

Networked predictive control for linear systems with quantizers by an event-driven strategy

In this paper, networked predictive control is investigated for a networked control system with quantizers by an event-driven strategy. An event generator is designed according to a deviation of state estimation between the current time and last trigger time. A predictive strategy is proposed to compensate effect of network-induced delays and packet dropouts. The quantizers are used to deal with signals by converting real-valued signals into effective ones in both feedback and forward channels. Based on a “zoom” strategy, sufficient conditions are given to ensure stabilization of the networked control system by solving linear matrix inequalities. A simulation example is proposed to exhibit advantages and availability of the developed techniques.