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1.
In this study, a Surface Computer Supported Cooperative Work paradigm is proposed. Recently, multitouch technology has become widely available for human–computer interaction. We found it has great potential to facilitate more awareness of human-to-human interaction than personal computers (PCs) in colocated collaborative work. However, other studies and modern operating systems have rarely been concerned with colocated interactions in their user interface (UI) design. Therefore, one UI framework, which we have named Surface Application Framework (SAF), is proposed to support multitouch and multiuser applications on tabletop computers. To explore the effects of wide area SAFs on colocated collaboration, one application, capable of making English sentences, was developed based on an SAF. This application was used to conduct a user-centric study to investigate differences between surface computers and PCs. The results show that a surface computer performs better than a PC in creating awareness during collaborative work, but it requires more time due to its poor performance with drag-and-drop operations. Finally, this study summarizes a three-dimensional design approach to consider various trade-offs between awareness and manipulative performances. Additionally, some mechanisms are suggested to be employed to overcome the weakness of drag-and-drop operations with multitouch interfaces in a future study. 相似文献
2.
This study was designed to explore the effects on learning of: (1) structural modifications to the periodic table, (2) the location of a periodic table within instructional materials, and (3) the presence of a two-page schema showing relationships between the topics explained in the written materials and the periodic table. One hundred and sixty high school students were randomly assigned to one of eight treatments. A 28-item posttest (KR –; 21 = 0.72), consisting of multiple choice and constructed answer items, was designed to measure subjects' ability to use their periodic tables to obtain factual information and to solve qualitative chemistry problems. Regression analyses using the multiple choice portion of the posttest as a dependent variable and table type as an independent variable revealed that for subjects with minimal experience with the periodic table, those who received the table with added visual data performed significantly better than subjects who received either of the other two tables (df 3,93; F = 2.72; p < 0.05). For subjects familiar with the periodic table, significant vocabulary X table (df 3,49; F = 3.22; p < 0.05) and vocabulary X location (df 1,49; F = 4.46; p < 0.05) interactions were detected. Subjects high in verbal comprehension tended to take advantage of the modified tables, while those low in verbal comprehension processed the traditional table with less information most effectively. These latter students also benefited more from having the periodic table alongside their written materials. 相似文献
3.
In order to compensate for the limitation of conventional XY table used in semiconductor integrated circuits(IC) packaging and improve its speed and accuracy, a voice coil actuator (VCA) direct-drive high-speed and precision positioning XY table used in wire bonder was proposed. Also, a novel flexible decoupling mechanism was used in the positioning table, and the small moving mass enabled the positioning table to move at high speed and precision. XY table deformation interference caused by assembly error and instant interference generated by dynamic load moving with high speed and acceleration can be eliminated through the flexible decoupling mechanism. Considering the positioning table as lumped mass spring system,the dynamic equations of the mechanical system and the VCA were built according to the Newton mechanics principle and electromagnetic theory. Then the electromechanical coupling control model of the system was created through Laplace transform. Based on displacement PID controller, the loop-locked controlling algorithm of the positioning system was investigated. The dynamic control algorithm effectively improved the system dynamic performance. The precision test of the prototype machine was carried out, and the results validated the correctness of the model and the theory. Compared with traditional XY table, the table has higher speed, acceleration and positioning accuracy. 相似文献
4.
Background: A substantial review study of concept cartoons reports that few studies have indicated their functions. For this reason, the present study illuminates the extent to which concept cartoon-embedded worksheets (through constructivist context) accomplish these functions in conceptual learning. Purpose: The purpose of the study is to determine the effect of the concept cartoon-embedded worksheets on grade 9 students’ conceptual understanding of Newton’s Laws of Motion. Sample: Within a quasi-experimental research design with control group, the sample consisted of 102 grade 9 students (aged 15–16 years) enrolled in an Anatolian High School. They were randomly assigned to control (52 students) and experimental groups (50 students). Design and methods: While the control group followed the existing physics instruction, the experimental one was exposed to the concept cartoon-embedded worksheets. To collect data, two scales (Newton’s Laws of Motion Test –NLMT– and Interview about Instances –IAI) were employed. Results: The results indicated that the experimental group performed better than did the control group. Conclusions: It can be deduced that the concept cartoon-embedded worksheets are effective in improving grade 9 students’ conceptual understanding and in replacing their alternative conceptions with scientific ones. 相似文献
5.
为了消除压电陶瓷的迟滞、蠕变等非线性对定位精度的影响 ,采用了非线性PID控制算法来实现微定位工作台的实时控制。利用跟踪微分器对信号进行跟踪并得到其微分信号 ,提高了控制系统的鲁棒性。通过计算机仿真 ,验证了所设计的微定位工作台的特性和闭环控制算法的有效性 相似文献
6.
针对工业机器人中厚板多层多道焊接参数选择的难题,采用基于查表的模糊控制方式,选取送丝速度和焊接速度为控制量,熔丝面积为被控制量,利用Matlab得出了各个变量之间的模糊控制表,用C#编写软件,实现了焊接参数的模糊控制。以25 mm厚对接平焊为例进行试验,结果表明该系统能将焊接后熔丝面积与实际焊接需要填充量的误差保持在5%以内。 相似文献
7.
鉴于当前工业网络控制实验装置普遍缺乏的现状,提出了一种基于总线的工业网络控制实验台的设计方案.通过对与之相关的功能结构、硬件、和软件等详细的讨论,设计出了功能齐全、性能可靠、简单易用、价格合理的工业网络控制实验台. 相似文献
8.
以美国卡莱轮胎公司为例,针对传统生产计划安排中存在的问题,提出了以含有生产时间、产量和主生产计划等为约束条件并对其进行最优化求解,进而实现了用MCR（Mixing Completion Rate,混合完成率）控制表对生产计划进行控制。实践证明,将此控制工具应用到卡莱轮胎公司中,成功地降低了企业库存,加速了企业资金流动,表明该控制工具在企业中具有良好的应用性。 相似文献
9.
In this study, patterns of variation in severities of a group of raters over time or so-called "rater drift" was examined when raters scored an essay written under examination conditions. At the same time feedback was given to rater leaders (called "table leaders") who then interpreted the feedback and reported to the raters. Rater severities in five successive periods were estimated using a modified linear logistic test model (LLTM, Fischer, 1973) approach. It was found that the raters did indeed drift towards the mean, but a planned comparision of the feedback with a control condition was not successful; it was believed that this was due to contamination at the table leader level. A series of models was also estimated designed to detect other types of rater effects beyond severity: a tendency to use extreme scores, and tendency to prefer certain categories. The models for these effects were found to be showing significant improvement in fit, implying that these effects were indeed present, although they were difficult to detect in relatively short time periods. 相似文献
10.
The objectives of this study are: (a) elaboration of a history and philosophy of science (HPS) framework based on a reconstruction of the development of the periodic table; (b) formulation of seven criteria based on the framework; and (c) evaluation of 57 freshman college‐level general chemistry textbooks with respect to the presentation of the periodic table. The historical reconstruction of the periodic table showed that the periodicity of the elements could be construed as an inductive generalization or as a function of the atomic theory. There is considerable controversy with respect to the nature of Mendeleev's contribution, and various alternatives are discussed: ordered domain; empirical law; and a theory with limited explanatory power. Accommodation of the elements according to their physicochemical properties is considered to be the major contribution of the periodic table by all textbooks, followed by contrapredictions of previously unknown elements (30 textbooks), and novel predictions (corrections of atomic mass) of known elements (10 textbooks). The relative importance of accommodation and prediction within an HPS framework is generally ignored. Few textbooks have attempted to explore the possible cause of periodicity in the table and very few textbooks have explored the nature of Mendeleev's contribution. The development of the periodic table as a sequence of heuristic principles in the form of a convincing argument has been ignored. The textbook approach of emphasizing that the development of the periodic table was an inductive generalization, and that Mendeleev had no model or theory, does not facilitate the spirit of critical inquiry that led the scientists to grapple with alternative interpretations, conflicts, and controversies. It is concluded that the development of the periodic table went through a continual critical appraisal (conflict and controversy), in which scientists presented various tentative theoretical ideas to understand the observed phenomena. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 42: 84–111, 2005 相似文献
11.
通过文献资料法,研究如何将快乐体育思想应用在高校乒乓球选修课中,对提高高校乒乓球选修课质量,培养选修课学生对乒乓球运动的兴趣具有积极意义.为此,分析了快乐体育、乒乓球选修课的特点,重点探讨了在高校乒乓球选修课教学中实施快乐体育的必要性,在此基础上提出在高校乒乓球选修课中实施快乐体育的具体措施. 相似文献
12.
由于数据库里的表多是相关表，它们之间很可能存在一对多的关系。本通过对Grid等控件属性、事件的设置，使一个表的记录与另一表的多个相关记录链接起来，用户可以在表中选定某个记录，而在另一个表所对应的表格中显示与这条记录相关的所有记录。本给出了销售系统中的一个例子。 相似文献
13.
设计并实现了一种基于多处理器的深海采矿实时调度控制系统，结合实时操作系统uC／OS—Ⅱ对深海机器人的轨迹规划、避障、故障监测等基本任务进行划分，将划分好的任务在多处理器系统中采用基于优先级表HVF调度算法实现全局动态调度。并在深海采矿多处理器控制系统中验证了算法设计，阐述了嵌入式系统用于深海采矿研究的有效性。 相似文献
14.
目的:探讨多点触控虚拟解剖系统在耳鼻咽喉科教学中的应用。方法:选取苏州大学医学院临床医学专业本科生的两个班级学生(A和B班),A为对照组,B为观察组,对两组学生分别进行传统教学以及多点触控虚拟解剖系统教学并评估学习效果。结果:观察组学生中同意新教学模式可提高学习热情、提升实践水平、拉近师生关系、强化知识点记忆以及树立团队合作意识的人员数量显著大于对照组(P<0.05);且在理论知识、考试成绩方面优于对照组(P<0.05)。结论:多点触控虚拟解剖系统在耳鼻咽喉教学中的应用存在重要的意义与价值。 相似文献
15.
A Direct Instruction approach to remedial reading (Corrective Reading Programme) was evaluated in an urban Comprehensive school over two school years. First year remedial readers were randomly allocated to one experimental and two control groups. Groups were matched for sex. A similar procedure was followed in the second study carried out with the following group of first year remedial readers. In the first three months of the first study all groups were monitored while receiving the school's usual remedial reading programme. They made comparable gains during this baseline period. Covariance analysis indicated that in the first study the experimental group and control group I (a ‘novelty’ programme) made significantly greater gains, in accuracy and comprehension, than control group 2 (the usual remedial reading programme). Findings from the second study confirmed the suggestion that gains for the experimental group in the first study were partly due to ‘novelty’ effects. Both experimental groups developed better strategies for tackling oral reading tasks (as assessed by miscue analysis) than control groups, however. 相似文献
16.
运用最小二乘法原理将模糊控制经验表转化为多参数解析式描述的模糊控制规则，并利用遗传算法对多参数解析式描述的模糊控制规则中所含参数进行优化，该方法对于具有缓慢变化过程即多级多档的模糊控制系统效果比较理想，具有一定的推广应用价值。 相似文献
17.
This study investigated transfer effects of gaze‐interactive attention training to more complex social and cognitive skills in infancy. Seventy 9‐month‐olds were assigned to a training group ( n = 35) or an active control group ( n = 35). Before, after, and at 6‐week follow‐up both groups completed an assessment battery assessing transfer to nontrained aspects of attention control, including table top tasks assessing social attention in seminaturalistic contexts. Transfer effects were found on nontrained screen‐based tasks but importantly also on a structured observation task assessing the infants’ likelihood to respond to an adult's social‐communication cues. The results causally link basic attention skills and more complex social‐communicative skills and provide a principle for studying causal mechanisms of early development. 相似文献
18.
Background: This study uses problem-based learning (PBL) to ensure that students comprehend the significance of green chemistry better by experiencing the stages of identifying the problem, developing hypotheses, and providing solutions within the problem-solving process. Purpose: The aim of this study is to research the effect of PBL implemented in cation analysis experiments in an analytical chemistry laboratory course on students’ level of understanding of the subject of ‘Green Chemistry and Sustainability’. The study group: The study group consists of second-grade students who participated in an Analytical Chemistry Laboratory within the General Chemistry III course in the Department of Science Education of the Faculty of Education of a state university in Turkey (N = 63). Design and methods: Quasi-experimental design was used in this research. Students were randomly divided into two groups, an experimental group (N = 31) and a control group (N = 32). Laboratory experiments in which qualitative and quantitative cation group analyses were conducted were carried out in the experimental group with PBL that involved five different scenarios inspired by daily life. In the control group, experiments were performed as closed-ended experiments. The ‘Green Chemistry and Sustainability Test’ (GCST) and semi-structured interviews were used as data collection tools. The independent sample t-test was used in determining whether there was a significant difference between groups by GCST, reviewing pre-test–post-test scores for the control and experimental groups, and semi-structured interviews were analyzed by content analysis. Results: The results showed that there was a significant difference in favor of the experimental group in GCST post-test scores (t = 10.554, p < 0.05). Considering students’ opinions, there were positive statements, such as that they had taken an active role and had their interest aroused interest since problems in the experiments were related to daily life. Conclusion: PBL enhanced students’ level of understanding of green chemistry and sustainability subjects and helped them obtain a different perspective in terms of environmental awareness. 相似文献
20.
文章介绍了在VB中用ADO控件、DataGrid控件对SQL Server数据库调用的方法以及ADO控件中两个关键属性连接字符串和记录源的设定方法。通过用VB设计C/S模式单表管理系统的实例,说明了如何用ADO控件实现对数据库记录的添加、修改、删除和查询。 相似文献
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