A Measurement and Structural Model for Usability Evaluation of Shared Workspace Groupware

This study presents the development process of a set of questionnaire items to establish a measurement model for the usability of shared workspace groupware systems, which is suggested as a usability scale called SWUS, the Shared Workspace Usability Scale. Manifest variables and latent variables are based on the various dimensions of teamwork collated through the literature. A structural model was built on the measurement model. Models were evaluated through PLS-SEM methods. Data acquired on candidate questionnaire items from 398 international respondents who are users of five different online collaborative word processors was used for the model analysis. Of 37 candidate manifest variables, 22 were retained, which were measuring seven latent constructs: “3C Mechanisms,” “Grounding,” “Team Integration,” “Communication,” “Shared Access,” “Awareness,” and “Usability.” The data provided empirical evidence for the structural model based on these latent variables. The responses of the participants were not sensitive to differences between users in terms of gender and native language but showed sensitivity to age, experience with the evaluated software, and different shared workspace groupware evaluated in the study. Our structural model attempts to integrate several frameworks and models of usability for CSCW environments and provides empirical evidence for its reliability and validity based on subjective responses from users of shared workspace groupware.     

Groupware Environments as Action Constitutive Resources: A Social Action Framework for Analyzing Groupware Technologies

Computer Supported Cooperative Work (CSCW) is a relatively new and dynamic field dealing with the development and use of groupware technologies in organizations. Several frameworks and models have been proposed for studying CSCW, each conveying a different perspective and theoretical basis. Although these frameworks have contributed much to our understanding of the field, they can be criticized for a lack of holistic understanding of the complex social activity that is constitutive of groupwork. This often leads to the failure of otherwise well designed CSCW applications. In this paper we take up this challenge and propose a social action framework for analyzing groupware technologies. The framework is based on Habermas's theory of social action and four action categories, and the idea that groupware applications serve as sets of rules and resources which mediate group interactions. We demonstrate the value of the framework by analyzing a wide range of existing groupware technologies for their appropriateness to specific groupwork situations in terms of their espoused or implicit assumptions of groupwork, and the action constitutive resources they provide. Our analysis points out that a host of current groupware applications can be fairly easily classified and examined by the way they are configured to support different types of social action. It also suggests that, when implementing groupware applications, developers should critically evaluate: (a) the need for supporting a rich variety of action types, (b) the possible role of computer support in the specific groupwork situations, and (c) the underlying assumptions of groupwork embedded in the groupware platform. Finally, we will discuss how the framework can inform future research and development in the field.     

A Framework for Composing Real-Time Schedulers

In this paper, we present a framework for integrating real-time components in the same system, where each component has its own scheduling algorithm. There are two main reasons for this research: to allow maximum flexibility in the design of systems with different real-time activities and to reuse already existing applications without changing their scheduling policy. After defining the concept of component in our context, we present our methodology that is based on a two-level hierarchical scheduling paradigm. At the global level, a scheduler selects which component must be executed at each instant; the selected component then chooses which task has to be scheduled depending on its own scheduling strategy.     

The MAUI Toolkit: Groupware Widgets for Group Awareness

Group awareness is an important part of synchronous collaboration, and support for group awareness can greatly improve groupware usability. However, it is still difficult to build groupware that supports group awareness. To address this problem, we have developed the Multi-User Awareness UI toolkit (MAUI) toolkit, a Java toolkit with a broad suite of awareness-enhanced UI components. The toolkit contains both extensions of standard Swing widgets, and groupware-specific components such as telepointers. All components have added functionality for collecting, distributing, and visualizing group awareness information. The toolkit packages components as JavaBeans, allowing wide code reuse, easy integration with IDEs, and drag-and-drop creation of working group-aware interfaces. The toolkit provides the first ever set of UI widgets that are truly collaboration-aware, and provides them in a way that greatly simplifies the construction and testing of rich groupware interfaces.     

嵌入式实时系统的快速开发框架研究

嵌入式实时开发是当今计算机应用研究的热点,该文结合模型驱动架构的系统无关模型和系统相关模型思想,提出了一种基于平台设计的快速开发嵌入式实时系统的方法:首先采用实时应用接口RTAI将嵌入式Linux改造成具有硬实时性能的实时操作系统平台;然后利用Matlab/Simulink/RTW和RTAI-Lab工具对实际系统进行快速化建模、仿真和驱动开发,并自动生成实时的可执行代码;最后将代码加载到嵌入式实时系统.通过倒立摆嵌入式实时控制器系统设计实例说明了这种方法可以有效降低系统设计复杂度,提高嵌入式软件的开发效率.     

A Framework for Software Fault Tolerance in Real-Time Systems

Real-time systems often have very high reliability requirements and are therefore prime candidates for the inclusion of fault tolerance techniques. In order to provide tolerance to software faults, some form of state restoration is usually advocated as a means of recovery. State restoration can be expensive and the cost is exacerbated for systems which utilize concurrent processes. The concurrency present in most real-time systems and the further difficulties introduced by timing constraints suggest that providing tolerance for software faults may be inordinately expensive or complex. We believe that this need not be the case, and propose a straightforward pragmatic approach to software fault tolerance'which is believed to be applicable to many real-time systems. The approach takes advantage of the structure of real-time systems to simplify error recovery, and a classification scheme for errors is introduced. Responses to each type of error are proposed which allow service to be maintained.     

A New Operational Transformation Framework for Real-Time Group Editors

Group editors allow a group of distributed human users to edit a shared multimedia document at the same time over a computer network. Consistency control in this environment must not only guarantee convergence of replicated data, but also attempt to preserve intentions of operations. Operational transformation (OT) is a well-established method for optimistic consistency control in this context and has drawn continuing research attention since 1989. However, counterexamples to previous works have often been identified despite the significant progress made on this topic over the past 15 years. This paper analyzes the root of correctness problems in OT and establishes a novel operational transformation framework for developing OT algorithms and proving their correctness     

A Real-Time Framework for Model-Predictive Control of Continuous-Time Nonlinear Systems

A new formulation of model-predictive control (MPC) for continuous-time nonlinear systems is developed, which allows for the use of ldquoreal-timerdquo (RT) optimization techniques in which the solution to the finite-horizon optimal control problem (OPC) evolves within the same timescale as the process dynamics. The computational savings of the RT solver are enhanced by the unique framework within which the OPC is posed, enabling significant reduction in the dimensionality of the search for situations where computational speed takes priority over optimality of the solutions. This framework, and its associated proof of stability, encompasses results on sampled-data (SD) nonlinear model-predictive control (NMPC) implementation as a special case.     

A Cascade Framework for a Real-Time Statistical Plate Recognition System

This paper describes a plate recognition system that can process images rapidly at high accuracy rates. This system is designed to meet the requirements of performance, computational speed, and adaptation for vehicle surveillance applications, such as stolen car detection systems. These requirements are satisfied by adopting a cascade framework, utilizing plate characteristics, and developing fast one-pass algorithms. Our system is composed of three main cascading modules for plate detection, character segmentation, and postprocessing. Each module is further decomposed into several cascading procedures, which are composed of successively more complex rejecters. The first module rapidly rejects a majority of nonplate regions by using low computational gradient features and a one-pass scanning algorithm followed by heavy computational statistical rejecters. The second module rejects a majority of noncharacter regions in a similar manner. A peak-valley analysis algorithm is proposed to rapidly detect all promising candidates of character regions. The third module eliminates the plate characters that do not satisfy the plate specifications. In our experiments, the system can recognize plates over 38 frames per second with a resolution of 640 times 480 pixels on a 3-GHz Intel Pentium 4 personal computer     

开放式实时环境中的集成调度框架

开放式实时环境中的多类型实时任务并存的情况给实时调度机制带来了新的需求和挑战．提出了一种适用于开放式实时环境的3层集成调度框架,它基于服务器方式的实时调度理论,把5种既有相关性又有功能互补特征的服务器有机的集成到统一的调度机制中．可支持多种类型的实时任务及非实时任务共存于同一系统的混合调度,并且根据它们的属性自动选择最合适的服务器与之搭配．相对于现有方法,该调度框架可支持的调度对象类型更广泛,易于进行服务质量控制,并且有良好的可扩展性．因此,更适合于开放式实时环境．     

Real-Time Transaction Scheduling: A Framework for Synthesizing Static and Dynamic Factors

Real-time databases are poised to be an important component of complex embedded real-time systems. In real-time databases (as opposed to real-time systems), transactions must satisfy the ACID properties in addition to satisfying the timing constraints specified for each transaction (or task). Although several approaches have been proposed to combine real-time scheduling and database concurrency control methods, to the best of our knowledge, none of them provide a framework for taking into account the dynamic cost associated with aborts, rollbacks, and restarts of transactions. In this paper, we propose a framework in which both static and dynamic costs of transactions can be taken into account. Specifically, we present: i) a method for pre-analyzing transactions based on the notion of branch-points for data accessed up to a branch point and predicting expected data access to be incurred for completing the transaction, ii) a formulation of cost that includes static and dynamic factors for prioritizing transactions, iii) a scheduling algorithm which uses the above two, and iv) simulation of the algorithm for several operating conditions and workload. Our dynamic priority assignment policy (termed the cost conscious approach or CCA) adapts well to fluctuations in the system load without causing excessive numbers of transaction restarts. Our simulations indicate that i) CCA performs better than the EDF-HP algorithm for both soft and firm deadlines, ii) CCA is more fair than EDF-HP, iii) CCA is better than EDF-CR for soft deadline, even though CCA requires and uses less information, and iv) CCA is especially good for disk-resident data.     

基于事件发布/订阅模式的协同感知框架

针对协同系统中感知问题.设计并实现了一个基于事件发布,订阅感知模式的协同感知框架.框架进一步规范了协同感知行为,增强了时感知行为的定义和控制,可为研制协同应用系统和扩展已有协同系统的感知功能提供帮助.框架设计的思想在对一个协同编辑系统的进行感知功能扩展应用中得到了验证.     

火电厂实时专家系统的框架设计

针对国内电站锅炉煤种不稳定、负荷变动频繁、操作运行人员工作强度大等特点,本论提出了用实时专家系统的方法实现锅炉运行管理的安全保护的思想,并且了一专家监控系统的框困。在本论中,详细阐述了该系统的结构设计思想,讨论了专家经验性和机理性领域的知识相结合使用的方法,然后还介绍了系统数据结构的定义和数据库的生成机制、推理机的工作方式等,在章的最后介绍了系统软件的组成各部分的功能。     

A Real-Time Data Mining Approach for Interaction Analytics Assessment: IoT Based Student Interaction Framework

Students’ interaction and collaboration with the fellows and teachers using the Internet of Things (IoT) based interoperable infrastructure is a convenient way. Measuring student attention is an essential part of the educational assessment for students’ interaction. As new learning styles develop, new tools and assessment methods are also needed. The focus in this paper is to develop IoT based interaction framework and analysis of the student experience in electronic learning (eLearning) so that the students can take full advantage of the modern interaction technology and their learning can increase to a high level. This setup has a data collection module, which is implemented using Visual C# programming language and computer vision library. The number of faces, number of eyes, and status of eyes are extracted from the video stream, which is taken from a video camera. The extracted information is saved in a dataset for further analysis. The analysis of the dataset produces interesting results for student learning assessments. Modern learning management systems can integrate the developed tool to consider student-learning behaviors when assessing electronic learning strategies. The tools are also developed for the data collection on both student and teacher ends. Correlation of data and hidden meaning are extracted to make the learning experience and teaching performance better and adaptable. IoT based infrastructure provides the facilities to fellow students about location awareness, fellows’ accessibility, social behavior and helping hand.     

二维协同工作空间的并发操作加锁协议

提出一种用于在二维工作空间中协同作业的并发操作加锁协议和相应的锁调度算法,协议采用悲观锁,以抽象的二维空间为并发操作的对象,支持任意锁粒度,具有无死锁性质．加锁协议和算法存一个实时分布式协同绘图系统中实现．协议的实现采用多Agent系统模型。将面向Agent的程序设计中Agent的情绪值的概念用于控制锁的释放和调度,支持并发操作者之间的主动协同和细粒度感知．     

Workspace for disabled people

The paper aims at determining the workspace for disabled young people. The investigation embraced a group of young people with motor dysfunction of lower extremities. Seventeen measurements were taken of 32 boys and 45 girls aged 15-18. There are significant differences in functional, dimensions of the arm between the healthy and the disabled populations. The differences clearly indicate that there is a need for different shaping of space in which people of limited motor efficiency must function. A method based on Das and Grady's concept was used in determining workspace. This method was modified by the author. The method allows determination of workspace by means of several simple anthropometric measurements. Workspace for young people investigated was determined for the sitting position in transverse and sagittal planes. The results of the investigation constitute data for design and estimation of workplaces for disabled young people with motor dysfunction of lower extremities. The results can also be used to determine functional space in classrooms, school workshops, educational and rehabilitation centres.     

Workspace for disabled people

The paper aims at determining the workspace for disabled young people. The investigation embraced a group of young people with motor dysfunction of lower extremities. Seventeen measurements were taken of 32 boys and 45 girls aged 15-18. There are significant differences in functional dimensions of the arm between the healthy and the disabled populations. The differences clearly indicate that there is a need for different shaping of space in which people of limited motor efficiency must function. A method based on Das and Grady's concept was used in determining workspace. This method was modified by the author. The method allows determination of workspace by means of several simple anthropometric measurements. Workspace for young people investigated was determined for the sitting position in transverse and sagittal planes. The results of the investigation constitute data for design and estimation of workplaces for disabled young people with motor dysfunction of lower extremities. The results can also be used to determine functional space in classrooms, school workshops, educational and rehabilitation centres.     

机器人操作臂工作空间的混合计算方法

机器人操作臂工作空间的形状和体积的精确计算对于其优化问题是非常重要的。为此首先根据从关节空间到工作空间的运动映射关系,使用蒙特卡洛方法产生由点组成的三维机器人工作空间。然后,通过把这些点分解成一系列的切片,获得机器人工作空间每层的二维边界曲线;基于切片曲线,由三维重构的方法产生边界曲面。最后,用数值积分的方法计算了机器人工作空间的体积。