基于分支定界法的相控阵雷达事件调度算法

为解决相控阵雷达事件调度问题中调度成功率、时间偏移率与算法时效性三者之间的矛盾，本文提出一种基于分支定界法的调度算法；该算法首先在现有调度结果上调取所有可执行事件，即获得若干"节点"，多步递推后由多"层"节点形成若干条备选"分支"，扩大解空间范围，提高算法性能；然后通过"删减"操作删减掉收益较低分支，将解空间控制在一适当范围内，减小搜索盲目性，降低算法计算量.仿真实验表明，与基于综合优先级算法的调度结果相比，利用本文算法调度时调度成功率提升了52%；与基于时间指针算法的调度结果相比，本身算法时间偏移率降低了61%；与基于遗传算法的调度结果相比，本文算法调度耗时仅为前者1~2%.     

How personal task management differs across individuals

There has been a wealth of research on how individuals manage their tasks in general. However little to none has investigated whether, how, and why personal task management (PTM) behaviors differ across individuals. To fill this gap, we conducted two empirical studies: a focus group + contextual interviews with 19 participants, and an online survey with 178 respondents. Initially, based on the results of the first study, we were able to summarize the differences and similarities across the individuals by categorizing the participants into three categories: DIYers, make-doers, and adopters.Then, we conducted a survey with a broader population to assess to what extent our previous results would generalize to a broader population. We found that many of the survey respondents did not fit neatly into one of the previous categories; rather, they demonstrated tendencies of varying strength toward adopting, make-doing, and DIYing for their PTM. This was reflected in how they recorded and remembered their tasks, and if/how they maintained task lists. Based on this, we recommend that PTM tools have the capacity to accommodate the varying strengths of those tendencies: they should be personalizable so that people with DIY desire can personalize their tool when they need to and should be relatively effortless to use and integrate well with other systems in use to satisfy make-do tendencies.     

Development of task analysis method for operator tasks in main control room of an advanced nuclear power plant

Task analysis methods provide an insight for quantitative and qualitative predictions of how people will use a proposed system, though the different versions have different emphases. Most of the methods can attest to the coverage of the functionality of a system and all provide estimates of task performance time. However, most of the tasks that operators deal with in a digital work environment in the main control room of an advanced nuclear power plant require high mental activity. Such mental tasks overlap and must be dealt with at the same time; most of them can be assumed to be highly parallel in nature. Therefore, the primary aim to be addressed in this paper was to develop a method that adopts CPM-GOMS (cognitive perceptual motor-goals operators methods selection rules) as the basic pattern of mental task analysis for the advanced main control room. A within-subjects experiment design was used to examine the validity of the modified CPM-GOMS. Thirty participants participated in two task types, which included high- and low-compatibility types. The results indicated that the performance was significantly higher on the high-compatibility task type than on the low-compatibility task type; that is, the modified CPM-GOMS could distinguish the difference between high- and low-compatibility mental tasks.     

Local interactions over global broadcasts for improved task allocation in self-organized multi-robot systems

We present a study of self-organized multi-robot task-allocation, examining performance under local and centralized communication strategies. The results extend our current understanding of the effects of communication by providing evidence that local strategies can improve system performance over centralized strategies, in terms of total task throughput as well as reduced communication overheads. The framework employed is the attractive field model, a generic model of self-organized division of labour derived from observations of ant, human and robot social systems. The framework provides sufficient abstraction to accommodate both communication strategies. Each of the studies used 16 e-puck robots in a simplified manufacturing environment where sensing and communication was realized using camera-based overhead tracking and centralized communication. In terms of task throughput, communication overhead and energy efficiency, the experimental results show that systems with restricted access to information perform better than systems with free flow of information. This suggests a potential paradigm shift where, for self-organizing systems, diminishing access to information renders a system more efficient.     

Verification of additional merits of a bimanual-coordinated rehabilitation robot using near-infrared spectroscopic technology

Using our designed robot, previous work has confirmed that bimanual training induced greater oxygenated-hemoglobin concentration than unilateral-limb training. However, the inter-hemispheric asymmetry of oxygenated-hemoglobin concentration was not compared between the bimanual and unilateral-limb patterns. To confirm the merits of our designed robot based on cerebral hemoglobin activation, 18 healthy subjects performed bimanual and unilateral-limb tasks in active-resisted mode and active-assisted mode for the right and left control sides (determines from that which limb provides a larger force). Analyses of variance were performed to compare the laterality index (LI) of two hemispheres between the two control sides, and to compare oxygenated-hemoglobin concentration between the different training patterns. The difference of LI between the two control sides was distinct in unilateral-limb patterns (p?=?0.029) but not obvious in bimanual patterns. As for the oxygenated-hemoglobin, active-resisted tasks induced a higher concentration than active-assisted tasks in the left control side (p?=?0.048). Results demonstrated that the proposed bimanual training induced the functional integrity of two hemispheres, and the robot is favorable for improving bimanual movement-coordination function. Additionally, active-resisted tasks had a higher difficulty level than active-assisted task. Therefore, the robot has a potential for delivering strength enhancement training in bimanual patterns.     

A case for information theory-based modelling of human multitasking performance

Technological advances have led to increased prevalence of human multitasking. Traditionally, multitasking performance is measured for each individual task, utilising multiple performance metrics. Recently, the human operator informatic model (HOIM) has been developed as a quantitative model of human–machine interaction capable of measuring multitasking performance with a single metric. In this study, we investigated the performance effects of both a different number of tasks and five different task combinations while maintaining a constant level of overall difficulty. Results indicate that, at a constant difficulty level, neither number of tasks nor task combination significantly affects multitasking performance, indicating the reliability of input baud rate as a measure of system complexity. No task interaction effects were found among the different tasks. This study demonstrates the application of information theory for modelling of human multitasking performance and makes a case for the use of the HOIM in future studies of human information processing.     

The effect of individual and task characteristics on decision aid reliance

This research explores reliance behaviours of decision-makers using a decision aid. Objective and subjective task characteristics in the form of task complexity and task difficulty, respectively, are examined, along with the effect of the individual characteristic of expertise. A total of 130 subjects (65 novices and 65 experienced practitioners) completed a lab experiment using a decision aid (Insolve-DG) to help them make decisions for two insolvency tasks with differing levels of complexity. The research finds that the objective task characteristic (task complexity) and individual characteristic (expertise) both affect reliance behaviours; however, their effects are fully mediated by the subjective task characteristic (task difficulty). Expertise and task complexity are both associated with the degree of task difficulty experienced by an individual user: increasing task complexity increases task difficulty, and increasing expertise reduces task difficulty. Task difficulty and task complexity are established as different constructs; and importantly it is task difficulty, not task complexity, that ultimately affects reliance.     

最晚截止期优先带宽转让算法

基于最早截止期优先调度的实时系统，针对有新任务插入(与/或)现行任务加速但系统带宽不足的问题，提出一种最晚截止期优先(LDF)算法，用于系统在运行时选择现行任务转让带宽。采用从最晚作业截止期任务开始判断的方法，经过尽可能少的比较次数，找到合适的受压任务，平滑地完成带宽转让。算法需要的最多比较次数为2n。仿真结果表明，该算法在大多情况下只需要比较1~2次即可完成压缩任务。     

The effects of achromatic and chromatic color schemes on participants' task performance in and appraisals of an office environment

This study explores the effects of chroma on participants' performance and environmental appraisal of an office. The research was conducted in a full‐scale experimental room designed as a private office where achromatic and chromatic color schemes with coequal values were applied. Sixty participants were assigned tasks and given a questionnaire to appraise the spatial color schemes. The findings show that chroma significantly affects performance and space appraisal. In terms of accuracy and time spent performance scores measured significantly better in the room with the chromatic scheme than those in the room with the achromatic scheme. The office with the chromatic scheme was found to be more pleasant, attractive, satisfying and dynamic than the one with the achromatic scheme, whereas the achromatic scheme was thought to be more formal and harmonious. Categorization of pleasantness, harmony, dynamism and spaciousness by factor analysis also showed differences between the achromatic and chromatic schemes. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2012     

Learning while multitasking: short and long-term benefits of brain stimulation

Abstract

We employed a simulated production task that mimics the real-world skill acquisition required of operators working in control rooms of power plants to assess short and long-term effects of transcranial random noise stimulation (tRNS). tRNS has shown potential for enhancing learning and performance of cognitive skills. Forty subjects (24 female) learned how to execute the simulated production task during the training phase and were required to perform a secondary task during the skill acquisition phase while they received active (12?min) or sham tRNS on DLPFC. After 2 weeks they had to recall the task again without any stimulation. The results demonstrate that tRNS promoted better multitasking as reflected by better performance in a secondary task during and immediately after tRNS. However, 2 weeks later, beneficial effect of tRNS on retention was moderated by general mental ability. Particularly, tRNS benefited those with lower general mental ability.

Practitioner summary: By using a simulated production task, we assessed the effects of tRNS on learning and skill retention. The study indicates that neurostimulation can enhance the learning of multiple complex tasks. Moreover, it shows that retention of those tasks can be supported by neurostimulation, especially for those with lower general mental ability.