语义网本体构建工具现状及发展趋势研究

本体构建是语义Web的一个研究热点,目前不同组织开发了多种本体构建工具.本文在详细全面调研现有本体构建工具的基础上,对七种本体构建工具进行了比较分析,指出了它们某些关键特性的差异.最后,对现状中存在的瓶颈问题进行了总结,并对未来的研究方向提出了具体建议.     

USE of Railway Analysis Tools from an Australian Perspective

The functions of Australia’s railways are divided between the delivery of suburban passenger railway services, long distance general and intermodal freight services and regional bulk commodity haulage. There is a national interest in the efficient carriage of export freight flows because Australia is a major trading nation. Australia’s railways are expected play their part in hauling export commodities. Unsurprisingly, there are conflicting demands on these railways. Hence, universities, and the industry itself, are directing research and investigation effort into policy, planning, engineering, operational and human factors matters. A question which then arises is what means could be used to analyse the problems identified during this research and investigation. This paper is thus concerned with the inter-relationships between the planning, engineering and operations of railways in Australia. It identifies four areas of analysis associated with the planning and development of railway infrastructure and operations. It then discusses a range of analytical tools which could be applied to different components of these analytical areas and critiques their appropriateness from an Australian perspective. Having made this assessment, the paper uses a recent Australian case study to show how analytical tools could be used and what lessons might be learnt from the process. Figure Use of Railway Analysis Tools from an Australian Perspective

Certification of software for real-time safety-critical systems: state of the art

This paper presents an overview and discusses the role of certification in safety-critical computer systems focusing on software, and partially hardware, used in the civil aviation domain. It discusses certification activities according to RTCA DO-178B “Software Considerations in Airborne Systems and Equipment Certification” and touches on tool qualification according to RTCA DO-254 “Design Assurance Guidance for Airborne Electronic Hardware.” Specifically, certification issues as related to real-time operating systems and programming languages are reviewed, as well as software development tools and complex electronic hardware tool qualification processes are discussed. Results of an independent industry survey done by the authors are also presented.     

面向移动Agent的软件度量工具的设计

利用软件度量工具对软件的各类质量属性度量,对于提高程序的质量有重要意义。在分析面向移动Agent的度量指标的基础上,设计并实现一种基于移动Agent的软件度量工具,该工具通过度量Agent与系统中其它Agent进行交互来获取度量所需信息并对其进行加工处理,用户可以通过度量Agent提供的接口查询度量的结果。最后给出度量指标与度量特征之间关系的实验结果。     

Web系统性能测试研究

Web系统的性能测试是Web应用开发过程中的一个关键环节,然而Web站点的复杂性及其用户行为的不可预见性使得对其性能测试极其困难,而且测试环境和用户使用环境的差异性使得Web系统性能测试数据不精确或不可靠。分析了Web系统结构和Web系统的性能特点,深入讨论了Web系统性能测试的内容和性能测试的原理,并比较了目前常用的性能测试工具,通过一个测试项目介绍了自动化测试的实施过程,总结出一套切实可行的Web系统性能测试流程。     

Error compensation in machine tools: a neural network approach

For a non-idealized machine tool, each point in the workspace is associated with a tool point positioning error vector. If this error map can be determined, then it is possible to substantially improve the positioning performance of the machine by introducing suitable compensation into the control loop. This paper explores the possibility of using an artifical neural network (ANN) to compute this mapping. The training set for the ANN is obtained by mounting a physical artifact whose dimensions are precisely known in the machine's workspace. The machine, equipped with a touch trigger probe, measures the positions of features on the artifact. The difference between the machine reading and the known dimension is the machine error at that point in the workspace. Using standard modeling techniques, the kinematic error model for a CNC turning center was developed. This model was parameterized by measurement of the parametric error functions using a laser interferometer, electronic levels and a precision square. The kinematic model was then used to simulate the artifact-measuring process and develop the ANN training set. The effect of changing artifact geometry was explored and a machining operation was simulated using the ANN output to provide compensation. The results show that the ANN is capable of learning the error map of a real machine, and that ANN-based compensation can significantly reduce part-dimensional errors.     

Effects of the handle diameter and tip angle of chopsticks on the food-serving performance of male subjects

The effects of chopsticks handle diameter and tip angle on the food-serving performance of pinching food, pulling food, shearing food and thrusting food, were investigated in this study. A total of 24 male subjects was tested using 12 pairs of experimental chopsticks, consisting of three types of different handle diameters and four types of different tip angles. These results indicated that chopstick handle diameter and tip angle have a significant influence on eating efficiency, and that these two variables have a significant interaction. In addition, chopstick tip diameter also had significant effects on performance at the four tasks and subjective ratings. Generally, according to the results, when the chopsticks design is presented in terms of handle diameter, tip angle and tip diameter, a pair of chopsticks with 6 mm handle diameter × 2 ° tip angle × 4 mm tip diameter would be optimum.     

VA + Embeddings STAR: A State-of-the-Art Report on the Use of Embeddings in Visual Analytics

Over the past years, an increasing number of publications in information visualization, especially within the field of visual analytics, have mentioned the term “embedding” when describing the computational approach. Within this context, embeddings are usually (relatively) low-dimensional, distributed representations of various data types (such as texts or graphs), and since they have proven to be extremely useful for a variety of data analysis tasks across various disciplines and fields, they have become widely used. Existing visualization approaches aim to either support exploration and interpretation of the embedding space through visual representation and interaction, or aim to use embeddings as part of the computational pipeline for addressing downstream analytical tasks. To the best of our knowledge, this is the first survey that takes a detailed look at embedding methods through the lens of visual analytics, and the purpose of our survey article is to provide a systematic overview of the state of the art within the emerging field of embedding visualization. We design a categorization scheme for our approach, analyze the current research frontier based on peer-reviewed publications, and discuss existing trends, challenges, and potential research directions for using embeddings in the context of visual analytics. Furthermore, we provide an interactive survey browser for the collected and categorized survey data, which currently includes 122 entries that appeared between 2007 and 2023.     

X‐ray diffraction (XRD)‐studies on the temperature dependent interface reactions on hafnium,zirconium, and nickel coated monocrystalline diamonds used in grinding segments for stone and concrete machining

Diamond impregnated metal matrix composites are the state of the art solution for the machining of mineral materials. The type of interface reactions between the metal matrix and diamond surface has an essential influence on the tool performance and durability. To improve the diamond retention, the diamonds can be coated by physical vapour deposition with metallic materials, which enforce interface reactions. Hence, this paper focuses on the investigation of the interfacial area on metal‐coated monocrystalline diamonds. Hafnium and zirconium, both known as carbide forming elements, are used as coating materials. The third coating, which is used to determine its catalytic influences when applied as a physical vapour deposition (PVD)‐layer, is nickel. Additionally, the coated diamond samples were heat‐treated to investigate the starting point of the formation of new phases. X‐ray diffraction‐analyses revealed the assumed carbide formation on hafnium and zirconium coated samples. The formation temperature was identified between 800 °C and 1000 °C for hafnium and zirconium coatings.     

不同配比Ni-Cr系涂层非线性动力学系统的抗腐蚀性能研究

采用非线性动力学系统的BP数据网络进行管材涂层腐蚀性能预测。首先采用增重法获取9种腐蚀工况下的增重数据,将获取的数据用于构建BP神经网络模型,通过传输和反演操作设置拓扑结构为6×15×1的BP神经网络,然后基于90组实验数据用于验证和评价BP神经网络预测模型,最后通过对优选出的涂层进行Ni-Cr系涂层的机理分析,从而解决生物质电站锅炉"四管"的腐蚀问题,研发的抗腐蚀涂层具有较好的经济性和实用性。