基于任务-网络模型的装甲车辆乘员脑力负荷评价方法研究

以多资源理论(MRT)为基础,充分考虑装甲车辆乘员作业特点,从人的信息处理方式入手建立了基于信息执行通道的乘员任务-网络模型,提出了基于任务-网络模型的装甲车辆乘员脑力负荷评价方法。以装甲车辆炮长发现目标并射击任务操作为实例进行分析评价,结果表明,该方法能够清楚地描述乘员全任务过程中脑力负荷的变化情况,有效地找出脑力负荷异常的时间节点和产生原因,量化评估乘员的脑力负荷。     

Adaptive Multimodal In‐Vehicle Information System for Safe Driving

This paper proposes an adaptive multimodal in‐vehicle information system for safe driving. The proposed system filters input information based on both the priority assigned to the information and the given driving situation, to effectively manage input information and intelligently provide information to the driver. It then interacts with the driver using an adaptive multimodal interface by considering both the driving workload and the driver's cognitive reaction to the information it provides. It is shown experimentally that the proposed system can promote driver safety and enhance a driver's understanding of the information it provides by filtering the input information. In addition, the system can reduce a driver's workload by selecting an appropriate modality and corresponding level with which to communicate. An analysis of subjective questionnaires regarding the proposed system reveals that more than 85% of the respondents are satisfied with it. The proposed system is expected to provide prioritized information through an easily understood modality.     

驾驶员对北京市道路交通标志的感知和理解

通过模拟在交通标志引导下到达指定地点的过程,研究了北京市道路交通标志信息量以及驾驶员脑力负荷对感知和理解道路交通标志的影响.在已有研究的基础上,改进了交通标志信息量的计算方法.相关分析结果表明,该方法很好地拟合了驾驶员对交通标志信息量的主观评价.方差分析结果表明:1)信息最的大小对驾驶员感知和理解交通标志没有显著影响;2)脑力负荷对交通标志识别率、决策时间、决策正确率以及决策确信程度有显著影响;3)脑力负荷对主观任务负荷和识别交通标志的时间没有显著影响.     

Performance of B+ tree concurrency control algorithms

A number of algorithms have been proposed to access B⁺-trees concurrently, but they are not well understood. In this article, we study the performance of various B⁺-tree concurrency control algorithms using a detailed simulation model of B⁺-tree operations in a centralized DBMS. Our study covers a wide range of data contention situations and resource conditions. In addition, based on the performance of the set of B⁺-tree concurrency control algorithms, which includes one new algorithm, we make projections regarding the performance of other algorithms in the literature. Our results indicate that algorithms with updaters that lock-couple using exclusive locks perform poorly as compared to those that permit more optimistic index descents. In particular, the B-link algorithms are seen to provide the most concurrency and the best overall performance. Finally, we demonstrate the need for a highly concurrent long-term lock holding strategy to obtain the full benefits of a highly concurrent algorithm for index operations.     

心理负荷多维主观评定的实验研究

本研究在总结前人成果的基础上将心理负荷主观反应归纳为“任务难度”等８个方面，并结合追踪作业负荷实际加以实验检验。通过敏感性分析和因素分析，作者最终提出“任务复杂性”、“任务压力”、“心理努力与疲劳”和“紧张水平”是主观心理负荷最重要的维度，建议设计多维主观评定量表时考虑这４个方面。     

Coping With Downsizing: A Comparison of Executive-Level and Middle Managers.

A longitudinal study compared the reactions of executive-level and middle managers prior to a large-scale downsizing, during initial and final phases, and following the downsizing. Compared with executives, middle managers perceived greater job insecurity, were more likely to use escape coping, and reported lower job performance and higher levels of health symptoms. Over time, both executives and middle managers reported a decline in perceived threat of job loss but an increase in sense of powerlessness, a decrease in the use of control-oriented coping strategies, and reduced job performance in the initial phase of downsizing. Although less so, executive-level managers were also adversely affected by the downsizing, suggesting that this group should be included in stress management interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional processes in time perception: Effects of mental workload and event structure.

The role of attention in timing was evaluated in 2 experiments. In Experiment 1, participants reproduced the durations of melodies with either a coherent or an incoherent structure. Participants were tested under control (timing only) and detection (timing plus target detection) workload conditions. Reproductions were shorter and more inaccurate under detection conditions, and incoherent event structure extended the effect to a wider range of durations. In Experiment 2, participants reproduced the durations of auditory prose passages that represented 3 levels of mental workload and 3 levels of event structure. Both increases in workload and the degradation of structure led to inaccurate reproductions. The results point to the central role of attention in temporal experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

提高物探工程投资效益的措施

通过研究单位长度和面积的“点数”、覆盖次数、“点次”及一次面积与满次面积比值的大小与工程投资的关系,认为减少资料采集工作中的工程量——点次,是提高地震勘探效益的根本措施;减少地震工程中的测量工程量、钻井进尺是提高地震勘探效益的其他途径。随着地震仪器的发展,覆盖次数越来越高,当覆盖次数达到一定次数后,把一定的附加面积当作勘探面积,从而减少点次,也不失为提高地震勘探效益的又一条措施。     

Design and Implementation of a Multimodal Input Device Using a Web Camera

We propose a novel input pointing device called the multimodal mouse (MM) which uses two modalities: face recognition and speech recognition. From an analysis of Microsoft Office workloads, we find that 80% of Microsoft Office Specialist test tasks are compound tasks using both the keyboard and the mouse together. When we use the optical mouse (OM), operation is quick, but it requires a hand exchange delay between the keyboard and the mouse. This takes up a significant amount of the total execution time. The MM operates more slowly than the OM, but it does not consume any hand exchange time. As a result, the MM shows better performance than the OM in many cases.