基于FPGA的多声路超声波定位系统

设计一种以FPGA为控制器的多声路超声波障碍物定位系统。多个超声波传感器分时工作,利用FPGA高速处理的能力采用动态扫描的方式提取信息进行处理,通过VGA显示监视范围内障碍物空间分布情况及物体的移动情况。实验证明,系统具有较高的测量精度及较强的灵活性。适当改进后可用于车辆行进路线监测,机器人避障等。     

基于CC1101射频技术的室内超声定位系统

待定位物的三维坐标监测是室内定位的一个重要指标.文中采用射频技术作为测距时的内部同步设置,考虑到室内布局的复杂性,待定位点到各个已知参考节点的测距值的集中定位计算采用无线数据传输.通过应用射频芯片CC1101和ATmega48控制芯片组成的射频信号收发模块,实现了超声测距时的内部同步和无线数据传输,提高了定位的精度、增加系统灵活性,并适于特殊的场合.利用LabVIEW软件实现最终数据处理,使得设计直观、适应性更强.     

基于GPS定位与超声波导盲拐杖的设计

针对市场上供盲人使用的导盲拐杖结构简单,功能单一,无法实现较好导盲效果的弱点,设计了一款以单片机AT89C52为主控件,具有GPS坐标定位、超声波测障、语音提示等功能的智能拐杖;介绍了智能拐杖的组成结构和工作原理;在分析GPS信号语句格式和处理流程的基础上,设计了硬件电路和实现软件编程;利用超声波发射和接受电路实现了测障报警功能;基于SYN6288语音合成芯片实现定位、时间信息的语音输出功能;有效地实现了导盲拐杖智能化操作和多功能扩展。     

智能穿戴超声波测距可定位导盲腰带研究与设计

采用超声波原理,以STC89C52单片机作为主控核心,设计一款智能穿戴超声波测距可定位导盲腰带。该装置可以给处于行走状态的盲人进行道路障碍的实时探测,障碍物的实时距离信息以语音播报方式实现传送,使盲人获取其周围环境情况,并通过附带GPS定位、GSM通信功能保障盲人出行安全。此腰带设计采用的设备成本较低并易于批量生产,测距误差小,作为盲人出行的辅助工具有较高的实用价值。     

Indoor Hovering Control of Small Ducted-fan Type OAV Using Ultrasonic Positioning System

This study focused on a development of attitude stabilization and a position (hovering) control scheme of the SFR (Small Flying Robot). The platform type of the SFR is a ducted-fan type OAV having a diameter of 30 cm. The attitude of the SFR was successfully stabilized by a PD control method. In the attitude control loop, the feedback states were angle and angular rates, which were outputs from an AHRS (Attitude Heading Reference System). The position of the SFR was controlled precisely by the LQI (Linear Quadratic Integration) method with a Kalman filter. In the position control loop, an ultrasonic positioning system was used for the 3D position reference, which was developed in a previous research. The proposed simple mathematical model could analyze dynamics and stability of the SFR. Also, the stabilities of the attitude control and the precision of the position control were verified by comparing and analyzing data of experiments and simulations.     

基于超声测距的三维精确定位系统与设计

讨论了一种新型的基于超声测距的高精度三维定位系统的原理与设计。该定位系统采用波头计数与零交叉点检测的方法来提高超声测距精度,并通过三角形方法来实现三维定位。这种三维定位系统具有精度高、成本低、易于安装、体积小、抗电磁干扰能力强、对光线不敏感、无电磁辐射等优点。     

Accessible network of performance index tables

In each of the information processing apparatuses connected to each other via a network, there is arranged a quality of service (QOS) table to which functions and performance thereof are registered. When an information processing apparatus is additionally linked with the network, a QOS table thereof is automatically registered to a local directory of the network such that an agent converts the contents of the QOS table into service information to be supplied via a user interface to the user. Thanks to the operation, information of functions and performance of each information processing apparatus connected to the network is converted into service information for the user. Consequently, the user can much more directly receive necessary services.     

基于红外超声光电编码器的室内移动小车定位系统

介绍一个二轮驱动移动小车的,定位系统,采用红外超声三边测距的绝对定位方法和光电编码器航迹推算的相对定位方法,比较准确的测量了小车的运行轨迹和方向,并解决了传统单纯依靠红外超声定位存在的盲区问题,实验说明此方法具有可行性。     

Guidelines for Creating Accessible Library Web Pages

ABSTRACT

Library Web developers can improve their Web pages and work towards accessibility by all user groups. This article describes some general accessibility guidelines to follow when creating Web pages. It discusses the recommendations of the World Wide Web Consortium (W3C), called the Web Accessibility Initiatives (WAI). This article focuses attention on the accessibility of Web pages to users with visual impairments, auditory impairments, and mobility impairments. Accessibility guidelines for these user groups are suggested. Another important aspect of creating accessible Web pages is to test the pages during and after development. Online products that test accessibility are discussed as well as additional test methods, such as user input.     

用Registerdatabase创建可访问ODBC的数据源

ＯＤＢＣ提供了ＯＤＢＣ管理器来对数据源做手动改变。但是用户要安装一个新的数据源 ,应用程序是不能让用户做这些事 ,那么如何用代码来完成这一工作呢 ?ＶＢ提供的ＲＥＧ ＩＳＴＥＲＤＡＴＡＢＡＳＥ方法是用ＯＤＢＣ注册一个新的数据源的快速简单的方式。它的语法是ＤＢＥｎｇｉｎｅ .ｒｅｇｉｓｔｅｒＤａｔａＢａｓｅｄｂ ｎａｍｅ ,ｄｒｉｖｅｒ,ｓｉｌｅｎｔ,ａｔｔｒｉｂｕｔｅｓ。其中 :Ｄｂｎａｍｅ:是在ｏｐｅｎｄａｔａｂａｓｅ中使用的名字的字符串表达式 ,它是指关于数据源的一块描述信息。Ｄｒｉｖｅｒ:是用来访问数据库的Ｏ…     

Random Accessible Mesh Compression Using Mesh Chartification

Previous mesh compression techniques provide decent properties such as high compression ratio, progressive decoding, and out-of-core processing. However, only a few of them supports the random accessibility in decoding, which enables the details of any specific part to be available without decoding other parts. This paper proposes an effective framework for the random accessibility of mesh compression. The key component of the framework is a wire-net mesh constructed from a chartification of the given mesh. Charts are compressed separately for random access to mesh parts and a wire-net mesh provides an indexing and stitching structure for the compressed charts. Experimental results show that random accessibility can be achieved with competent compression ratio, which is only a little worse than single-rate and comparable to progressive encoding. To demonstrate the merits of the framework, we apply it to process huge meshes in an out-of-core manner, such as out-of-core rendering and out-of-core editing.     

An Accessible Platform for People With Disabilities

This article discusses a modular, accessible platform that provides a computing environment for people with disabilities accessible through adapted control devices and the television set at users’ homes. Relying on a standard television set as the presentation device allows dependent individuals, especially people with disabilities, to introduce new technological advances in communication and information management in their everyday lives. As a proof-of-concept, the solution presented offers a collection of educational and training services related to teleworking and the search of employment targeted to people with disabilities. A smart job advisor included among these services, which was designed to help our target users to locate job offers that best suit the abilities and disabilities of a particular individual, is also discussed to illustrate how semantic technologies can be applied to increase the perceived accessibility and inclusion by reducing the dependence from other persons. The platform developed, the introduction of semantic technologies, and the way adapted interfacing and presentation devices were integrated may also serve as inspiration to provide services to people with disabilities.     

Random Accessible Hierarchical Mesh Compression for Interactive Visualization

This paper presents a novel algorithm for hierarchical random accessible mesh decompression. Our approach progressively decompresses the requested parts of a mesh without decoding less interesting parts. Previous approaches divided a mesh into independently compressed charts and a base coarse mesh. We propose a novel hierarchical representation of the mesh. We build this representation by using a boundary-based approach to recursively split the mesh in two parts, under the constraint that any of the two resulting submeshes should be reconstructible independently.
In addition to this decomposition technique, we introduce the concepts of opposite vertex and context dependant numbering . This enables us to achieve seemingly better compression ratios than previous work on quad and higher degree polygonal meshes. Our coder uses about 3 bits per polygon for connectivity and 14 bits per vertex for geometry using 12 bits quantification.     

Engineering Accessible Web Applications. An Aspect-Oriented Approach

The development of accessible Web software is complicated for several reasons. Though some of them are technological, the majority are related with the need to compose different and, many times, unrelated design concerns which may be functional as in the case of most of the specific application’s requirements, or non-functional such as Accessibility itself. In this paper, we present a novel approach to conceive, design and develop Accessible Web applications in an aspect-oriented manner. In order to reach our goal, we provide some modeling techniques that we specifically developed for handling the non-functional, generic and crosscutting characteristics of the Accessibility concerns. Specifically, we have enriched User Interaction Diagrams with integration points, which are used to reason and document Accessibility for activity modeling during user interface design. Then by instantiating a Softgoal Interdependency Graph template with association tables, we work on an abstract interface model (composed by ontology widgets) to obtain a concrete and accessible interface model for the Web application being developed. We use a real application example to illustrate our ideas and point out the advantages of a clear separation of concerns throughout the development life-cycle.     

Accessible interactive television using the MPEG-21 standard

In this paper, the accessibility of interactive television (iTV) is discussed as a primary factor for its satisfactory adoption and commercial success. The work presented here is undertaken in the context of a research project that focuses on delivering iTV services to disabled children. This objective is accomplished through the utilization of the arising MPEG-21 standard. Based on that standard, iTV accessibility is investigated in terms of metadata and content adaptation. The novelty of the contribution lies on a systematic methodology that deals with a wide range of accessibility problems, as opposed to previous studies that focus mostly on users with only one specific disability.     

Accessible software development: a conceptual model proposal

Universal Access in the Information Society - Equal access to all software and digital content should be a reality in the Digital Era. This argument is something defended both by existing...     

Accessible wayfinding and navigation: a systematic mapping study

Urban environments, university campuses, and public and private buildings often present architectural barriers that prevent people with disabilities and special needs to move freely and independently. This paper presents a systematic mapping study of the scientific literature proposing devices, and software applications aimed at fostering accessible wayfinding and navigation in indoor and outdoor environments. We selected 111 out of 806 papers published in the period 2009–2020, and we analyzed them according to different dimensions: at first, we surveyed which solutions have been proposed to address the considered problem; then, we analyzed the selected papers according to five dimensions: context of use, target users, hardware/software technologies, type of data sources, and user role in system design and evaluation. Our findings highlight trends and gaps related to these dimensions. The paper finally presents a reflection on challenges and open issues that must be taken into consideration for the design of future accessible places and of related technologies and applications aimed at facilitating wayfinding and navigation.