The MurMur project: Modeling and querying multi-representation spatio-temporal databases

Successful information management implies the ability to design accurate representations of the real world of interest, in spite of the diversity of perceptions from the applications sharing the same database. Current database management systems do not provide representation schemes that preserve each perception while fully supporting their diversity and maintaining their consistency. This is a major hindrance for building an all-embracing view of the world while serving multiple applications, whether it is by developing a single database or by providing transparent access (e.g., via the Web) to several heterogeneous data sources (that would typically hold a great diversity of stored representations). This paper reports on results from the multiple representations and multiple resolutions in geographical databases project,¹ funded by the European Commission under the 5th Framework Programme. The objective of the project has been to enhance GIS (or DBMS) by adding functionality that supports multiple coexisting representations of the same real-word phenomena (semantic flexibility), including representations of geographic data at multiple resolutions (cartographic flexibility). The new functionality enables a semantically meaningful management of multi-scale, integrated, and temporal geo-databases.     

Debugging with dynamic slicing and backtracking

Programmers spend considerable time debugging code. Symbolic debuggers provide some help but the task remains complex and difficult. Other than breakpoints and tracing, these tools provide little high-level help. Programmers must perform many tasks manually that the tools could perform automatically, such as finding which statements in the program affect the value of an output variable for a given test case, and what was the value of a given variable when the control last reached a given program location. If debugging tools provided explicit support for these tasks, the debugging process could be automated to a significant extent. In this paper we present a debugging model, based on dynamic program slicing and execution backtracking techniques, that easily lends itself to automation. This model is based on experience with using these techniques to debug software. We also present a prototype debugging tool, SPYDER, that explicitly supports the proposed model, and with which we are performing further debugging research.     

Algorithmic Debugging and Hypothetical Reasoning

This paper presents a generalization of Shapiro style algorithmic debugging for generalized Horn clause intuitionistic logic. This logic offers hypothetical reasoning and negation is defined not by failure but by inconsistency. We extend Shapiro's notion of intended interpretation, symptoms and errors and give formal results paralleling those known for definite clauses. We also show how a corresponding diagnosis module for RISC- a logic programming system for generalized Horn clause intuitionistic logic-can be defined by meta interpretation. In contrast to Shapiro's PROLOG modules ours work independently of the specific computation rule that in RISC may be specified by the user.     

Learning to Think and Communicate with Diagrams: 14 Questions to Consider

This paper looks at the particular role which diagrammatic representations, and external representations more generally, play within an educational context. In particular, it considers the way in which the demands on diagrammatic representational systems in educational settings differ with respect to other settings (e.g. professional): in some instances, these demands are increased, while in others, the demands are markedly different.The paper considers three key issues: the question of whether diagrams make certain tasks easier (and whether this is desirable from an educational point of view), the generalisation and transfer of diagrammatic skills once learnt, and the possible problems associated with simultaneously learning domain knowledge and a novel representational system.The paper then considers a number of sub-issues, and concludes by highlighting areas of particular interest for future AI research.     

Analytics of learning tactics and strategies in an online learnersourcing environment

Background

The use of crowdsourcing in a pedagogically supported form to partner with learners in developing novel content is emerging as a viable approach for engaging students in higher-order learning at scale. However, how students behave in this form of crowdsourcing, referred to as learnersourcing, is still insufficiently explored.

Objectives

To contribute to filling this gap, this study explores how students engage with learnersourcing tasks across a range of course and assessment designs.

Methods

We conducted an exploratory study on trace data of 1279 students across three courses, originating from the use of a learnersourcing environment under different assessment designs. We employed a new methodology from the learning analytics (LA) field that aims to represent students' behaviour through two theoretically-derived latent constructs: learning tactics and the learning strategies built upon them.

Results

The study's results demonstrate students use different tactics and strategies, highlight the association of learnersourcing contexts with the identified learning tactics and strategies, indicate a significant association between the strategies and performance and contribute to the employed method's generalisability by applying it to a new context.

Implications

This study provides an example of how learning analytics methods can be employed towards the development of effective learnersourcing systems and, more broadly, technological educational solutions that support learner-centred and data-driven learning at scale. Findings should inform best practices for integrating learnersourcing activities into course design and shed light on the relevance of tactics and strategies to support teachers in making informed pedagogical decisions.     

某系统阵地通话器调试与维修设备研制

介绍了配套某系统阵地语音通话器的调试与维修设备研制,重点探讨了其主要技术与功能,及设备构成的主机和分机的技术设计,阐述了具有独立调试与维修设备系统的组成及应用,尤其具备语音通信的树叉应用结构模型,既是调试设备,也是独立的语音通信设备。该设备具有稳定、可靠、高效运行的特点,保障了某系统关联应用的效能。     

How do argumentation diagrams compare when student pairs use them as a means for debate or as a tool for representing debate?

The objective of the research presented here was to study the influence of two types of instruction for using an argumentation diagram during pedagogical debates over the Internet. In particular, we studied how using an argumentation diagram as a medium of debate compared to using an argumentation diagram as a way of representing a debate. Two groups of students produced an individual argument diagram, then debated in pairs in one of the two conditions, and finally revised their individual diagrams in light of their debate. We developed an original analysis method (ADAM) to evaluate the differences between the argumentation diagrams constructed collaboratively during the interactions that constituted the experimental conditions, as well as those constructed individually before and after debate. The results suggest a complementary relationship between the usage of argumentation diagrams in the framework of conceptual learning. First, students who were instructed to use the argumentation diagram to represent their debate were less inclined to take a position in relation to the same graphical element while collaborating. On the other hand, students who were instructed to use the argumentation diagram alongside a chat expressed more personal opinions while collaborating. Second, the instructions given to the participants regarding the use of the argumentation diagram during the collaborative phase (either for debate or for representing a chat debate) have a significant impact on the post-individual graphs. In the individual graphs revised after the collaborative phase, participants who used the graph to represent their debate added more examples, consequences and causes. It follows that a specific usage for an argumentation diagram can be chosen and instructions given based on pedagogical objectives for a given learning situation.     

The Localization and Correction of Errors in Models: A Constraint-Based Approach

Model-based diagnosis, and constraint-based reasoning are well known generic paradigms for which the most difficult task lies in the construction of the models used. We consider the problem of localizing and correcting the errors in a model. We present a method to debug a model. To help the debugging task, we propose to use the model-base diagnosis solver. This method has been used in a real application of the development a model of a railway signalling system.     

GDB远程调试及其在嵌入式Linux系统中的应用

嵌入式Linux系统的研究和应用越来越热。针对如何完成系统调试工作的问题,本文首先介绍了GDB远程调试技术在该领域的应用概况,然后从剖析GDB远程调试的工作机制入手,具体描述了实现该调试手段的一般方法,重点介绍了使用GDB远程调试功能在嵌入式Linux系统中调试各类程序代码的应用实例。     

Learning from abstract and contextualized representations: The effect of verbal guidance

An experiment examined the effects of providing explicit verbal guidance to learners in integrating information with abstract or contextualized representations during computer-based learning of engineering. Verbal guidance supported learners in identifying correspondences and making mental connections among multiple textual and diagrammatic representations. Results from a 2 (abstract (A) or contextualized (C) representation) × 2 (no guidance or guidance) design showed that without guidance, abstract representations led to better transfer than contextualized representations. Moreover, learners in the contextualized representation group benefitted from the guidance, while the abstract representation group did not benefit from guidance. These findings suggest that abstract representations promote the development of deep, transferrable knowledge and that verbal guidance denoting correspondences among representations can facilitate learning when less effective representational formats are utilized.     

Recent Progress in Software Testing, Debugging and Analysis: A Survey

This article is a survey on the recent progress of some hot topics of software engineering. The survey is based on the review on the papers of three premier conferences on software engineering from 2012 to 2013. Through the quantitative analysis on these papers, there are three hot topics identified, software testing, debugging, and analysis. Focusing on these three topics, this article summarizes some new achievements in these fields, analyzes the characteristics of these works, and points out some directions for future research.     

A software system for evaluation and training of spatial reasoning and neuroanatomical knowledge in a virtual environment

This paper describes the design and development of a software tool for the evaluation and training of surgical residents using an interactive, immersive, virtual environment. Our objective was to develop a tool to evaluate user spatial reasoning skills and knowledge in a neuroanatomical context, as well as to augment their performance through interactivity. In the visualization, manually segmented anatomical surface images of MRI scans of the brain were rendered using a stereo display to improve depth cues. A magnetically tracked wand was used as a 3D input device for localization tasks within the brain. The movement of the wand was made to correspond to movement of a spherical cursor within the rendered scene, providing a reference for localization. Users can be tested on their ability to localize structures within the 3D scene, and their ability to place anatomical features at the appropriate locations within the rendering.     

大型泵站机组调试系统

本文描述了大型泵站机组调试系统的功能以及机组故障诊断方法等,介绍了机组调度系统开发要点和实现方案。     

Development of a real-time visual and force environment for a haptic medical training simulator

In this article, a real-time, visual and force environment for a 5-dof haptic urological training simulator is presented that deals with a low-force, high-deformation environment. A real-time graphical representation of the male urethra during the insertion of an endoscope is developed. Smooth urethra deformations are produced by a mesh of piece-wise Bézier interpolations, while its inner wall is simulated by realistic tissue textures. Efficient real-time techniques are developed that introduce endoscope camera depth-of-field effects. A novel particle-based model computes in real-time the forces fed to the haptic device. A 13 fps refresh rate is achieved on a 2-GHz computer with the depth-of-field effect activated, while the rate is doubled to 26 fps with this feature disabled. It is expected that the simulator will contribute to ethical, efficient, and modern surgical training.     

系统仿真及OPC技术在系统调试中的应用

在自动化系统制造或改造过程中,为了能够实现对控制系统软件的充分离线调试,从而能够在软件上线运行前尽可能多地排除控制系统软件中的缺陷,采用系统仿真和过程控制中的对象连接与嵌入(OPC)技术是一个好的选择。通过系统仿真技术,在软PLC中开发必要的控制对象仿真模型,并通过OPC实现与控制系统之间的连接,从而使得控制系统软件能够在虚拟的自动化生产线上进行在线调试和运行,以排除软件缺陷,测试软件性能。