人机交互中基于时间约束的人体工效模型

针对人机交互领域速度-准确度折中关系的预测中任务完成精确度的预测模型较为欠缺的问题,提出了一种基于时间约束的精确度模型预测方法。该方法采用了人机交互研究中常用的受控实验测试分析法,研究了在计算机用户界面中要求用户在给定的时间内完成任务时,任务完成的精确度与给定的时间约束之间的折中关系,用以衡量完成时间约束任务的人体工效。实验中设计了一系列受时间约束的轨道滑动任务,实验环境中自变量包括轨道长度、轨道宽度以及规定的在轨道中滑动的时间,因变量为任务完成的精确度,采用在轨道中滑动时轨迹的纵向偏差表示。通过对30位被试者实验数据的分析发现,任务完成的精确度与轨道宽度以及滑动速度(表示为轨道长度/规定的滑动时间)之间构成线性的关系,在此基础上采用最小二乘方回归法建立了一个基于时间约束的任务完成精确度的量化模型;该模型与真实实验数据集的拟合优度达到了0.857。     

Balancing risk and cost in fuzzy economic dispatch including wind power penetration based on particle swarm optimization

Utilization of renewable energy resources such as wind energy for electric power generation has assumed great significance in recent years. Wind power is a source of clean energy and is able to spur the reductions of both consumption of depleting fuel reserves and emissions of pollutants. However, since the availability of wind power is highly dependent on the weather conditions, the penetration of wind power into traditional utility grids may incur certain security implications. Therefore, in economic power dispatch including wind power penetration, a reasonable tradeoff between system risk and operational cost is desired. In this paper, a bi-objective economic dispatch problem considering wind penetration is formulated, which treats operational costs and security impacts as conflicting objectives. Different fuzzy membership functions are used to reflect the dispatcher’s attitude toward the wind power penetration. A modified multi-objective particle swarm optimization (MOPSO) algorithm is adopted to develop a power dispatch scheme which is able to achieve compromise between economic and security requirements. Numerical simulations including sensitivity analysis are reported based on a typical IEEE test power system to show the validity and applicability of the proposed approach.     

随机Oblivious路由算法中随机性与时间代价的研究

本文研究了分布式随机Oblivious路由算法中随机性与时间代价的关系。证明了：对于n个结点，最大结点度为d的图G及其上的任意一个分布式随机路由算法，若该算法以概率Q(1/2相似文献   

电厂燃煤分类分仓控制系统研究

优化配煤是电厂降低成本、提高效益的关键一环,而燃煤的分类分仓储存是实现优化配煤的前提。为了实现优化配煤,电站燃煤分类分仓问题的基本任务就是将若干种燃煤,按照要求分成若干类,分别储存在不同的筒仓内,以满足下一步配煤燃烧的要求。针对电厂筒仓储煤的特点,以电厂实际案例为对象,提出了一种电厂燃煤分类分仓储存控制方案。采用两两比较法权衡热值、挥发分、硫分、灰分和单价等指标的权重;采用灰色综合聚类分析法依据上述指标对燃煤进行分类,有效地克服了以往的分类方法在聚类系数无显著性差异的情况下无法确定对象所属灰类的问题;采用专家系统实现燃煤的分仓储存。实际案例证明,该方法能够满足现场运行的要求,有一定的理论意义和工程实用价值。     

The discrete time/cost trade-off problem: extensions and heuristic procedures

Time/cost trade-offs in project networks have been the subject of extensive research since the development of the critical path method (CPM) in the late 50s. Time/cost behaviour in a project activity basically describes the trade-off between the duration of the activity and its amount of non-renewable resources (e.g., money) committed to it. In the discrete version of the problem (the discrete time/cost trade-off problem), it is generally accepted that the trade-off follows a discrete non-increasing pattern, i.e., expediting an activity is possible by allocating more resources (i.e., at a larger cost) to it. However, due to its complexity, the problem has been solved for relatively small instances. In this paper we elaborate on three extensions of the well-known discrete time/cost trade-off problem in order to cope with more realistic settings: time/switch constraints, work continuity constraints, and net present value maximization. We give an extensive literature overview of existing procedures for these problem types and discuss a new meta-heuristic approach in order to provide near-optimal heuristic solutions for the different problems. We present computational results for the problems under study by comparing the results for both exact and heuristic procedures. We demonstrate that the heuristic algorithms produce consistently good results for two versions of the discrete time/cost trade-off problem.     

"Inhibition of Return: Sensitivity and Criterion as a Function of Response Time": Correction to Ivanoff and Klein (2006).

Reports an error in the original article, "Inhibition of Return: Sensitivity and Criterion as a Function of Response Time" by Jason Ivanoff and Raymond M. Klein (Journal of Experimental Psychology: Human Perception and Performance, 2006 Aug, Vol 32[4], 908-919). On page 912, there are typographical errors in Table 1. On page 915, the last line of the left column incorrectly states that the mean response frequencies for Experiment 2 are presented within Table 2. The corrected information for both pages is presented here. (The following abstract of the original article appeared in record 2006-09006-009.) Inhibition of return (IOR) refers to a mechanism that results in a performance disadvantage typically observed when targets are presented at a location once occupied by a cue. Although the time course of the phenomenon--from the cue to the target--has been well studied, the time course of the effect--from target to response--is unknown. In 2 experiments, the effect of IOR upon sensitivity and response criterion under different levels of speed stress was examined. In go/no-go and choice reaction time tasks, IOR had at least 2 distinct effects on information processing. Early in target processing, before sufficient target information has accrued, there is a bias against responding to cued targets. Later, as target information is allowed to accrue, IOR reduces sensitivity to the target's nonspatial feature. Three accounts relating to the early bias effect of IOR and the late effect of IOR on sensitivity are offered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory operations that support language comprehension: Evidence from verb-phrase ellipsis.

Comprehension of verb-phrase ellipsis (VPE) requires reevaluation of recently processed constituents, which often necessitates retrieval of information about the elided constituent from memory. A. E. Martin and B. McElree (2008) argued that representations formed during comprehension are content addressable and that VPE antecedents are retrieved from memory via a cue-dependent direct-access pointer rather than via a search process. This hypothesis was further tested by manipulating the location of interfering material—either before the onset of the antecedent (proactive interference; PI) or intervening between antecedent and ellipsis site (retroactive interference; RI). The speed–accuracy tradeoff procedure was used to measure the time course of VPE processing. The location of the interfering material affected VPE comprehension accuracy: RI conditions engendered lower accuracy than PI conditions. Crucially, location did not affect the speed of processing VPE, which is inconsistent with both forward and backward search mechanisms. The observed time-course profiles are consistent with the hypothesis that VPE antecedents are retrieved via a cue-dependent direct-access operation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于小波的支持向量机预测模型及应用

基于统计学习的预测方法在一定程度上依赖于大量数据的基础假设,但在实际应用中时间序列样本往往是有限的,论文提出了一种基于小波的支持向量机预测模型(WSVMFM)。通过小波框架的平移所生成的平方可积空间中的一组完备的基可以构造为支持向量机(SVM)的核函数,而采用该核函数的 SVM(WSVM)可以逼近平方可积空间中的任意函数,从而提高学习和预测效率。将该预测模型应用于基于多智能代理的电子商务交易模型中可较好地解决交易状态表示及预测等问题。     

Architecture-level performance/power tradeoff in network processor design

With the ever-increasing performance and flexibil-ity requirements in networks,the development of pro-grammable network processors is fast.Network proces-sors are used both in the middle of the network,as wellas at the edges of the network in enterprise c…     

Extremely randomized trees

This paper proposes a new tree-based ensemble method for supervised classification and regression problems. It essentially consists of randomizing strongly both attribute and cut-point choice while splitting a tree node. In the extreme case, it builds totally randomized trees whose structures are independent of the output values of the learning sample. The strength of the randomization can be tuned to problem specifics by the appropriate choice of a parameter. We evaluate the robustness of the default choice of this parameter, and we also provide insight on how to adjust it in particular situations. Besides accuracy, the main strength of the resulting algorithm is computational efficiency. A bias/variance analysis of the Extra-Trees algorithm is also provided as well as a geometrical and a kernel characterization of the models induced. Editor: Johannes Fürnkranz