Modeling task completion time of in-vehicle information systems while driving with keystroke level modeling

The use of touchscreen-based in-vehicle information systems (IVIS) is increasing. To ensure safe driving, it is important to evaluate IVIS task performance during driving situations. Therefore, we proposed a model to assess the task completion time (TCT) of IVIS tasks while driving using a keystroke-level modeling (KLM) technique. The basic assumptions and heuristic rules of driver behaviors were considered. In addition, based on the characteristics of visual and manual IVIS interactions, we determined the basic unit operators (i.e., visual, manual, and mental operators). User experiments were conducted to determine the individual execution times of unit tasks and to measure the TCT of IVIS tasks while driving. Based on the heuristic rules for model development and individual task execution times, we derive a predictive model for the TCT of IVIS tasks. We used a regression analysis to validate the modeling procedure, showing that the observed TCT was found to have a strong positive correlation with the predicted time from the modeling process. The findings showed that the task completion time needed to perform a secondary task in a driving context can be predicted by KLM. This study provides meaningful insights into the design of touchscreen-based IVIS to enhance driving safety.     

Analysis of the Cognition Involved in Spreadsheet Software Interaction

This article analyzes details of the cognition involved when people use spreadsheet software, a task that is both a major microcomputer application and a cognitively intense task. This task is analyzed in terms of the GOMS model (Card, Moran, & Newell, 1983), to test the generality of the model and to extend its set of parameters. We found that people using two seemingly similar spreadsheet applications, Lotus 1-2-3 and Multiplan, require very different amounts of time to accomplish the same tasks. Experienced users of Lotus 1-2-3 took far longer to complete the same four tasks than experienced Multiplan users did. It was found that some of additional time was due to the fact that Lotus 1-2-3 offers users a choice of two general methods to enter formulas. Lotus requires that the user decide which to use; this decision takes time. And, when the users type the address of the cell in which values reside instead of using the cursor to point to it, they pause a long time before typing each entry. Presumably they are scanning the screen and calculating the coordinates to type in during the pause. Again, these cognitive processes take time. In an analysis of a second task-adjusting the column width-there was substantial evidence that the performance changes when a method is repeated in close succession. This repetition affects the parameters that reflect the time it takes to retrieve command parts from memory. When the parameters for scanning, decision, and repetition were added to the keystroke analysis of our task, we found remarkable correspondence with the basic parameters from the Card et al. (1983) original work: The keystroke times and mental preparation times from their original experiments were very close to the estimates of those same parameters in our tasks. However, in our analysis of the spreadsheet task, we expanded the parameter set in the keystroke model to account for performance in tasks that require substantial planning, scanning, and repetition.     

AutoCAD实用技巧

AutoCAD在工程界得到了广泛的应用，学习和掌握AutoCAD也逐渐地成为工程设计人员必备的技能之一。本文主要介绍AutoCAD软件的一些辅助命令及绘图技巧，提高工程制图的效率，促进工程界的甩图板进程。     

AutoCAD实用技巧

AutoCAD在工程界得到了广泛的应用,学习和掌握AutoCAD也逐渐地成为工程设计人员必备的技能之一。本文主要介绍AutoCAD软件的一些辅助命令及绘图技巧,提高工程制图的效率,促进工程界的甩图板进程。     

基于特征命令交换的在线协同设计方法

在线协同设计中特征命令的并发执行将导致文档状态的不确定,其直接后果是造成拓扑对象编码/命名冲突。为此,将状态向量作为特征命令执行文档状态的简化描述形式以方便参与者间的通信,结合各个参与者本地的特征命令队列以及几何模型对特征命令的执行文档状态进行精确描述。基于该精确描述方法对特征命令的本地和远端执行文档状态进行分析,提出特征命令执行文档状态确定化算法以保证拓扑对象编码/命名的正确有效性。     

3D空间复杂楼梯面可视化快速参数建模

空间复杂楼梯面的智能化建模问题是建筑、装饰等行业的难点、热点问题.本文以AutoCAD VBA作为开发工具,给出3D空间复杂楼梯面可视化参数快速建模方法,并对复杂楼梯面的生成算法与技巧进行了研究,使空间复杂楼梯面模型的设计更具敏捷化、智能化和可交互性.开发的设计程序可作为AutoCAD命令嵌入到AutoCAD绘图软件中,以提高用户的设计效率.     

Fault management in process control: eye movements and action

Operators controlled a simulated thermal hydraulic system based on Crossman's waterbath task. They were required to keep the system at set points for temperature, level and flow rates. The system was subjected to disturbances and to failures, which the operators were required to manage. Behavioural data were collected in the form of keystroke commands, and in addition eye movements were measured. Evidence for 'cognitive lockup' and for a preference for serial fault management were found. Fixation durations do not change, but faulty subsystems are examined more frequently. During lockup other subsystems may be examined but action on them is delayed. Eye movements give considerable additional insight into the nature of process control information processing compared with traditional measures of operator performance.     

A Statistical Method for Software Quality Control

This paper proposes a statistical method that can be used to monitor, control, and predict the quality (measured in terms of the failure intensity) of a software system being tested. The method consists of three steps: estimation of the failure intensity (failures per unit of execution time) based on groups of failures, fitting the logarithmic Poisson model to the estimated failure intensity data, and constructing confidence limits for the failure intensity process. The proposed estimation method is validated through a simulation study. A method for predicting the additional execution time required to achieve a failure intensity objective is also discussed. A set of failure data collected from a real-time command and control system is used to demonstrate the proposed method.     

Fault management in process control: eye movements and action

Operators controlled a simulated thermal hydraulic system based on Crossman's waterbath task. They were required to keep the system at set points for temperature, level and flow rates. The system was subjected to disturbances and to failures, which the operators were required to manage. Behavioural data were collected in the form of keystroke commands, and in addition eye movements were measured. Evidence for ‘cognitive lockup’ and for a preference for serial fault management were found. Fixation durations do not change, but faulty subsystems are examined more frequently. During lockup other subsystems may be examined but action on them is delayed. Eye movements give considerable additional insight into the nature of process control information processing compared with traditional measures of operator performance.     

A comparison of several neural networks to predict the execution times in injection molding production for automotive industry

In the industrial environment, specifically in the automotive industry, an accurate prediction of execution times for each production task is very useful in order to plan the work and to optimize the human, technical and material resources. In this paper, we applied several regression neural networks to predict the execution times of the tasks in the production of parts for plastic injection molds. These molds are used to make a variety of car components in automotive industry. The prediction is based on the geometric features of the mold parts to be made. The accuracy of the predicted times is high enough to be used as a tool for the design stage of the mold parts, e.g. guiding the design process in order to get the lowest production time.     

A discrete event approach to the command sequence replanning and control in a teleprogramming system

A command sequence replanning and control method, which enables the slave system to autonomously recover from error conditions, is proposed in a telerobot system. A task model described as a form of the controlled Petri net (CPN) is used as a prior knowledge for the slave system to carry out the given task successfully without the operator's aid even in unexpected error conditions. The CPN model incorporates the contact states and transitional motions between them that possibly exist in the task execution process. The motion command is automatically generated from the master system and transmitted to the slave whenever the contact state changes in the master model. Referring to the CPN model and the given motion commands, the slave system detects if the actual contact state is unexpected and then plans the recovery path from the unexpected state. The feasibility of the command sequence replanning and control algorithm is verified through an example to perform a simple part‐mating task. © 2001 John Wiley & Sons, Inc.     

SharpMap二次开发中的框架设计与实现

商用地理信息系统软件庞大,且小规模系统的二次开发成本较高。为此,提出一种在开源SharpMap类库基础上进行框架设计与开发的方法,将命令和工具作为最小单元,各功能被细化成几个命令或工具,根据开发需要将命令与工具按照类别集成在一起构成系统。实验结果表明,该方法在二次开发中应用灵活,已开发的命令和工具单元可在多个项目中重复使用。     

An Effective and Practical Performance Prediction Model for Parallel Computing on Nondedicated Heterogeneous NOW

Networks of workstations (NOW) are receiving increased attention as a viable platform for high performance parallel computations. Heterogeneity and time-sharing are two characteristics that distinguish the NOW systems from conventional multiprocessor/multicomputer systems which are homogeneous and dedicated. It is important to have a practical model for users to predict the execution times of large-scale parallel applications on nondedicated heterogeneous NOW. Another objective of this study is to provide insight into the dynamic performance of parallel computing and into the effects of program structures and system factors on such a platform. In this paper, we study performance predictions for parallel computing on nondedicated heterogeneous networks of workstations. Our approach is based on a two-level model. On the top level, a semideterministic task graph is used to capture the parallel execution behavior including the variances of communication and synchronization. On the bottom level, a discrete time model is used to quantify effects from NOW systems. An iterative process is used to determine the interactive effects between network contention and task execution. We validate the prediction model using experiments on a nondedicated heterogeneous NOW. The maximum differences between predicted results and measured results were less than 10% in most cases and 15% in the worst cases.     

单步交互软件中支持用户意图预测的命令设计

针对单步交互的系统,基于MVC(Model View Contoller)和command模式设计系统结构,对交互命令及其参数进行封装;按照最后输入参数优先的原则实现用户选择和捕捉后,根据用户输入的参数预测候选命令集的交互方式;按照任务一致性原则根据用户以前的操作模式预测其当前行为;通过命令信息的保存和恢复,实现Undo,Redo及操作回放等功能.通过该方法实现的交互设计在虚拟施工软件中取得良好的效果.     

ATE中的远距离操作指令传输系统研究

为解决大型测试设备工作过程中多操作人员协同的问题,设计了一种基于串行总线的操作指令远距离传输系统;以AT89C52单片机为核心,利用RS-422总线实现显示末端与测试控制计算机的通讯;扩展存储芯片进行汉字符存储,指令信息通过点阵液晶显示;可显示所有测试过程及测试指令,实现下位机操作人员对主控计算机的响应及二者的通讯;应用实践表明系统可靠性高、抗干扰性强、人机交互友好,简捷地实现了.测试过程中的多操作人员协同,对于提高测试效率有显著效果.     

监控软件批处理命令设计

在通过计算机对设备、仪器进行远程控制的过程中,为提高操作的效率和准确性,减少误操作,提出了通过计算机软件集成控制的方式,将常用到的一组操作存储为一条批处理命令（脚本命令）,直接调用脚本命令即可实现对一组命令的处理,而不必一步步的进行操作,也不必关心每一步的执行顺序。介绍了脚本命令的组成,存储方式及界面组成、在工程实践中验证了该方案的可靠性和实用性。     

Predicting operational software availability and its applications to telecommunication systems

It is essential to predict customer-perceived software availability during software development and determine when to release the software to maintain a balance among time-to-market, development cost and software quality. This paper presents methods and procedures to predict software failure rates from a user perspective in system test phases and to reverse-engineer in order to estimate software release time for given availability targets. Software reliability analysis is conducted based on non-homogenous Poisson process models. Software system test data of current release are used to estimate the number of residual faults by the end of system tests and data of previous releases or similar products (including system test data, post-system test data and field failure data) provide a means to predict a user-perceived average failure rate of a fault. Software system availability can be predicted from these estimates. Both execution and calendar times are considered. A software resource utilization model is developed to transfer one testing time to another. A telecommunications application illustrates how to calculate the failure rate and testing time to meet the software availability requirements.     

A scheduling algorithm for applications in a cloud computing system with communication changes

This paper proposes a scheduling algorithm to solve the problem of task scheduling in a cloud computing system with time‐varying communication conditions. This algorithm converts the scheduling problem with communication changes into a directed acyclic graph (DAG) scheduling problem for existing fuzzy communication task nodes, that is, the scheduling problem for a communication‐change DAG (CC‐DAG). The CC‐DAG contains both computation task nodes and communication task nodes. First, this paper proposes a weighted time‐series network bandwidth model to solve the indefinite processing time (cost) problem for a fuzzy communication task node. This model can accurately predict the processing time of a fuzzy communication task node. Second, to address the scheduling order problem for the computation task nodes, a dynamic pre‐scheduling search strategy (DPSS) is proposed. This strategy computes the essential paths for the pre‐scheduling of the computation task nodes based on the actual computation costs (times) of the computation task nodes and the predicted processing costs (times) of the fuzzy communication task nodes during the scheduling process. The computation task node with the longest essential path is scheduled first because its completion time directly influences the completion time of the task graph. Finally, we demonstrate the proposed algorithm via simulation experiments. The experimental results show that the proposed DPSS produced remarkable performance improvement rate on the total execution time that ranges between 11.5% and 21.2%. In view of the experimental results, the proposed algorithm provides better quality scheduling solution that is suitable for scientific application task execution in the cloud computing environment than HEFT, PEFT, and CEFT algorithms.     

人机对话中自然语言任务命令的识别和计划

随着智能手机和智能系统的飞速发展, 使用自然语言对话的人机交互方式也成为了流行趋势. 但是如果该对话系统需要处理多功能任务类型, 那么将产生复杂的任务命令, 问题的维度也会增加. 尽管目前的NLP技术能提供一些解决方案, 但在动态范围内实现动态任务命令识别与处理的能力仍然有限, 解决复杂问题的效果还有待提高. 因此, 在本项工作中, 提供了一种结合NLP引擎和任务计划单元的方法, 根据自然语言的指令来设定任务计划, 以便对话系统能较准确地识别命令任务和相关参数, 并为任务生成相应的合理计划. 同时, 为解决自然语言对话中信息的歧义或遗漏, 还研究了一种对话策略, 在必要时能以最少的问答迭代收集对话信息.