Development of a pit filling algorithm for LiDAR canopy height models

LiDAR canopy height models (CHMs) can exhibit unnatural looking holes or pits, i.e., pixels with a much lower digital number than their immediate neighbors. These artifacts may be caused by a combination of factors, from data acquisition to post-processing, that not only result in a noisy appearance to the CHM but may also limit semi-automated tree-crown delineation and lead to errors in biomass estimates. We present a highly effective semi-automated pit filling algorithm that interactively detects data pits based on a simple user-defined threshold, and then fills them with a value derived from their neighborhood. We briefly describe this algorithm and its graphical user interface, and show its result in a LiDAR CHM populated with data pits. This method can be rapidly applied to any CHM with minimal user interaction. Visualization confirms that our method effectively and quickly removes data pits.     

基于Patran二次开发的飞机尾翼有限元建模方法

分析几种有限元建模的方法和平台的优缺点,用Patran的PCL通过增设特定的命令和窗体等开发飞机尾翼建模模块,并集成材料特性模块,形成一套由总体布局的几何信息直接生成,可进行应力分析的有限元建模系统.     

A compact hybrid feature vector for an accurate secondary structure prediction

Amino acid propensity score is one of the earliest successful methods used in protein secondary structure prediction. However, the score performs poorly on small-sized datasets and low-identity protein sequences. Based on current in silico method, secondary structure can be predicted from local folds or local protein structure. In biology, the evolution of secondary structure produces local protein structure with different lengths. To precisely predict secondary structures, we propose a derivative feature vector, DPS that utilizes the optimal length of the local protein structure. DPS is the unification of amino acid propensity score and dihedral angle score. This new feature vector is further normalized to level the edges. Prediction is performed by support vector machines (SVM) over the DPS feature vectors with class labels generated by secondary structure assignment method (SSAM) and secondary structure prediction method (SSPM). All experiments are carried out on RS126 sequences. The results from this proposed method also highlight the overall accuracy of our method compared to other state-of-the-art methods. The performance of our method was acceptable specifically in dealing with low number and low identity sequences.     

The effect of Twitter on college student engagement and grades

Despite the widespread use of social media by students and its increased use by instructors, very little empirical evidence is available concerning the impact of social media use on student learning and engagement. This paper describes our semester‐long experimental study to determine if using Twitter – the microblogging and social networking platform most amenable to ongoing, public dialogue – for educationally relevant purposes can impact college student engagement and grades. A total of 125 students taking a first year seminar course for pre‐health professional majors participated in this study (70 in the experimental group and 55 in the control group). With the experimental group, Twitter was used for various types of academic and co‐curricular discussions. Engagement was quantified by using a 19‐item scale based on the National Survey of Student Engagement. To assess differences in engagement and grades, we used mixed effects analysis of variance (ANOVA) models, with class sections nested within treatment groups. We also conducted content analyses of samples of Twitter exchanges. The ANOVA results showed that the experimental group had a significantly greater increase in engagement than the control group, as well as higher semester grade point averages. Analyses of Twitter communications showed that students and faculty were both highly engaged in the learning process in ways that transcended traditional classroom activities. This study provides experimental evidence that Twitter can be used as an educational tool to help engage students and to mobilize faculty into a more active and participatory role.     

高层二次供水泵站远程监控系统的设计与实现

近几年,各级政府开始要求城市供水企业将高层建筑二次供水纳入日常管理范围,为了达到科学高效的管理目标,提出采用计算机、网络和自控技术对二次供水泵站进行远程监控,并详细介绍了系统的建设目标、建设原则、网络结构、中心端硬软件配置、现场端数据采集和地址分配。该系统实现了不同型号设备跨平台的集成,在实践中具有推广价值。     

用VBA及ActiveX技术实现AutoCAD的二次开发

论述了利用 Auto CAD内嵌的 VBA语言开发工具和 Active X技术 ,阐明了 Auto CAD进行二次开发的基本理论和方法。     

A cross‐institutional approach to staff development in Internet communication

Abstract Recent upsurge in emphasis on larger class sizes and work‐based learning requires lecturers to be equipped to switch from traditional face‐to‐face teaching techniques to communicating with students using new technologies. Dialogue is the vital ingredient which underpins the successful learning experience, and staff in HE are facing a challenge in developing the necessary skills to make effective use of the emerging communication tools. These skills can only be acquired through practice, understanding of the pedagogy and awareness of the various options available. The aim of this paper is to explore, through presenting a case study, the potential benefits of cross‐institutional collaboration in information and communication technology staff development. Since both the University of Strathclyde and Glasgow Caledonian University were investigating ways of promoting good practice in the development and use of new learning technologies, it seemed prudent to combine forces and share ideas. The paper will examine how attempts were made to bridge the skills gap by enabling academic staff to experience Internet communication from the perspective of both student and teacher.     

Exploring novice users' training needs in searching information on the WWW

Abstract Searching for information on the WWW involves locating a website and locating information on that site. A recent study implied that novice users' training needs exclusively relate to locating websites. The present case study tried to reveal the knowledge and skills that constitute these training needs. Fourteen pre‐university students, classified as novice (n = 7) or experienced WWW‐user (n = 7) performed three web search tasks. Their actions and verbalisations were recorded. Between‐group comparisons showed minimal performance differences. However, qualitative analyses of novice users' search performance suggest that their ability to locate websites could be enhanced by instructing monitoring skills and advanced system knowledge.     

二次发射体MgO薄膜的俄歇电子能谱的研究

本文叙述了用PHI—550型给定的俄歇电子能谱(AES)研究了一种新的、性能优异的二次电子发射材料——MgO薄膜。薄膜由Ag—Mg合金经特殊高温激活工艺处理而成。以前人们对这种薄膜内部的各种元素的化学状态以及纵向原子浓度的分布状态一直不太清楚,本实验的成功证明了俄歇(Auger)电子能谱是研究这种薄膜的一种非常合适的实验方法。从实验结果中,我们发现如下几点 1.激活后,Mg和O原子的化学状态发生了显著的变化。 2.激活后,Mg、O和Ag原子的纵深分布也发生了显著的变化。 3.Mg原子氧化不充分,为了改进这一缺点,我们发明了一种新工艺。 4.使用新工艺激活,Mg原子可获充分氧化。     

气泡混合轻质土置换高速公路路堤工后沉降研究

以申嘉湖杭高速公路（练杭段）堆载预压处理段路基沉降速率较大断面采用气泡混合轻质土置换高速公路路堤为例,采用土体弹塑性本构模型及Sjerrum等时e—lgp曲线理论,对置换后地基土体的应力路径变化进行理论分析,地基土处于超固结状态;通过现场实测沉降资料,置换前处理段沉降观测点月沉降量在14mm～18mm,置换后沉降观测点月沉降量在2nm～4mm,沉降速率收敛较快,处理后效果明显,能够有效减少工后沉降。结果表明,采用气泡混合轻质土置换高速公路路堤不仅施工方便,质量容易控制,而且处理效果显著,是一种有效的减少软土地基工后沉降的控制方法。