操作风险等级预测的朴素贝叶斯方法研究

操作风险数据积累比较困难,而且往往不完整,朴素贝叶斯分类器是目前进行小样本分类最优秀的分类器之一,适合于操作风险等级预测。在对具有完整数据朴素贝叶斯分类器学习和分类的基础上,提出了基于星形结构和Gibbs sampling的具有丢失数据朴素贝叶斯分类器学习方法,能够避免目前常用的处理丢失数据方法所带来的局部最优、信息丢失和冗余等方面的问题。     

The effect of roll-stabilisation controllers on warship operational performance

At present, most ships are stabilised for roll using active fins controlled by a PID controller developed using classical control theory and these appear perfectly adequate for most warships. However, what is not known is how the choice of controller for a fin-stabilisation system affects the operational performance of the ship. This paper illustrates the potential improvements in the ability of a warship to perform an anti-submarine warfare mission in the North Atlantic when using different control strategies for fin-roll stabilisation. Also included is an assessment of the potential benefits to operational performance of an integrated fin rudder roll stabilisation system.     

机翼伸展对低速飞行状态的影响

变翼飞行器在飞行过程中因机翼构型、面积等发生变化,引起质量分布、惯性及气动特性发生相应改变,飞行动力学因此受到影响.基于Lagrange方程,本文首先建立变形机翼飞行器的动力学模型,简化后得到伸展变翼的纵向运动方程,并通过气动仿真获得伸展机翼飞行器的低速气动特性.然后,借助线性插值确定气动参数随翼展的变化关系,研究了伸展变翼过程对于飞行器平飞、爬升、俯冲和盘旋的作用.结果表明,因变翼过程中升阻系数改变,飞行器将发生变速沉浮运动,此时为保持飞行状态的稳定,需对飞行器加以控制.     

The influence of colour on CRT reading performance and subjective comfort under operational conditions

Performance and reports of comfort when proof-reading text displayed on a CRT were investigated as a function of the text/background colour. Luminances were those typically produced by commercially available hardware and software, and task conditions were designed to simulate those experienced by typical users. Colours from the extremes of the spectrum (red, blue) were shown to produce poorer reading performance, higher ratings of discomfort and a higher incidence of reported symptoms of discomfort than those from mid-spectrum and white stimulus conditions.     

A cross-sectional study of self-reported back and neck pain among English schoolchildren and associated physical and psychological risk factors

This study set out to identify the associations between ergonomics and other factors with back and neck pain among schoolchildren. Self-reported questionnaires were used to record health outcomes and potential risk factors in state schools. Six hundred and seventy-nine schoolchildren from Surrey in the United Kingdom aged 11–14 years took part. Twenty-seven percent of children reported having neck pain, 18% reported having upper back pain, and 22% reported having low back pain. A forward stepwise logistic regression was performed with pain categories the dependent variables. Neck pain was significantly associated with school furniture features, emotional and conduct problems, family history of low back pain and previous treatment for musculoskeletal disorders. Upper back pain was associated with school bag weight (3.4–4.45 kg), school furniture features, emotional problems and previous treatment for musculoskeletal disorders. Low back pain was associated with school furniture features, emotional problems, family history and previous injury or accident. It is important to recognise the influence of physical, psychological and family factors in children's pain.     

基于神经网络的飞参数据特征选择方法

针对飞参数据中存在的大量冗余和不相关,提出了一种基于神经网络的飞参数据特征选择方法.为克服传统算法收敛速度慢、易陷入局部极小等缺陷,神经网络的训练采用粒子群优化算法和Levenberg-Marquardt优化算法相结合的方式.神经网络训练结束后,先利用网络权值信息对飞参数据特征的相对重要度进行排序,然后根据重要度次序对飞参数据特征进行选择.实验结果表明该方法能快速有效地删除冗余飞参数据特征,同时提高网络的泛化能力.     

基于广域信息管理的飞行数据服务设计与实现

为实现标准、灵活、综合的飞行数据服务,解决专有的数据模型、紧耦合的系统接口和特定的传输协议造成的飞行数据“信息孤岛”问题,基于广域信息管理技术架构,采用面向服务的分层思想,对飞行数据服务进行整体设计。对服务实现的关键技术,包括广域信息管理架构的物理实现、公共飞行数据模型的建立、飞行数据访问服务的构建以及飞行数据的综合等进行分析研究。给出基于广域信息管理的飞行数据服务的实现实例。     

数据驱动的综合能源系统运行优化方法研究综述

构建清洁、低碳、安全、高效和可持续的现代能源体系被列为我国国家能源发展战略.综合能源系统(integrated energy system,IES)包含多类能源的产生、传输、转换、存储以及分配等过程,其综合管控与协同优化是在系统工艺与装备相对完备的情况下提升能源效率、降低成本、保护环境的关键技术,可为我国构建低碳可持续...     

The effect of information availability in a user interface (UI) on in-vehicle task performance: A pilot study

When performing an in-vehicle operation, the information display is a crucial element that decides the operator's control behaviors. The interaction between information presentation and operator's in-vehicle task performance is critical for vehicle safety. The question arises: What is the optimum availability of information? The aim of this study is to investigate the relationships between different information availabilities and operation performances as operators interact with an in-vehicle user interface (UI) to complete a simulated train driving task. The results show that some types of information significantly affect the operator's task performance. Information that improved the task performances were closely associated with specific task requirements. The participants' task performance indicated that they had a better awareness of a task situation and were better at controlling their virtual vehicle when completing time and process-restricted tasks with limited, relevant information. These results support the conclusion that more information does not always promote accuracy and safety during the task completion.Relevance to industryThis study presents a unique insight into the information display of in-vehicle UI design for vehicle control. The information available within an in-vehicle interface should be optimized by performance assessments to provide more useful information; this has significant positive effect on operator performance from an accuracy and safety perspective. Thus, this study provides advice for designing an in-vehicle UI.     

The effect of passive smoking on vigilance performance

Abstract

The present experiment was designed to test for effects of passive smoking on vigilance performance as well as to determine whether smokers and non-smokers are differentially affected by exposure to passive smoking. Four groups of subjects were used-smokers and non-smokers working in either clean or smoky air-and measures of decision time, movement time, correct detections, d' and β, were obtained together with ratings of mood. The results show that sensitivity and accuracy of both smokers and non-smokers was detrimentally affected by passive smoking, and that the onset of the effect was earlier for the non-smoking subjects than for the smoking subjects. In addition, passive smoking significantly reduced decision time for the non-smoking subjects although movement time and β were not significantly affected by exposure to the smoky environment. The findings indicate that both smokers and non-smokers may be adversely affected by passive smoking although effects may not appear until some time has elapsed. Data obtained from the mood scale show that feelings of anger and annoyance are increased by exposure to smoke and it is suggested that these feelings may contribute to the observed performance deficits.     

The effect of the environment of human performance

The performance of man, for a given level of ability, will be affected by his hygro-thermal, electro-ionic, visual and psychological microclimates. This paper presents the results of studies which demonstrate the effect of the hygro-thermal micro-climate on worker performance. The effects of the other micro-climates on worker performance are also discussed. For tasks with mainly physical activity performance depends upon metabolic heat. For tasks with mainly psychological activities there have, until now, been no specified criteria for determining the effects of the environment on performance. Consideration of the results of studies conducted in working environments clearly shows that environmental conditions can effect the efficiency of workers and hence that there are sound economic arguments for optimising working conditions.     

The effect of temporal psychological distance on reliance on word-of-mouth for information about destination image attributes

This study examines the effect of temporal psychological distance on travellers’ reliance on three types of word-of-mouth (WOM): traditional WOM (tWOM), social media WOM (SNS-WOM), and online review WOM (OR-WOM) in the search for information related to the relaxation, excitement, cost level, and safety destination image attributes. High and low temporal distance was manipulated using distances of 12 months and 2 months, respectively. A series of t-tests of 283 valid responses (155 and 128 for the 12-month and 2-month scenarios, respectively) shows a significant difference in reliance on tWOM when respondents sought safety attribute information, for SNS-WOM when respondents sought relaxation and safety attribute information, and for OR-WOM when respondents sought relaxation attribute information. Thus, this study shows that in terms of temporal distance, WOM is not a homogeneous block. They have sufficiently different characteristics (e.g. level of tie strength and synchronous/asynchronous modes), which, when they interact with the nature of the destination attributes, results in differing reliance on the three types of WOM under various temporal distances. This study thus contributes to construal level theory research and provides a better understanding of the different characteristics of the three types of WOM.     

基于超图的汉越双语新闻话题要素提取

针对汉越双语新闻话题文本集合中多语言、多文本的特点,在超图模型的基础上,运用PageRank随机游走排序方法提取出汉越新闻话题要素。首先根据触发词激励的方法提取新闻中的事件要素,然后在此基础上构建话题超图模型,将汉越事件要素作为结点,将文本集合中的句子作为超边,根据概率评估函数计算结点和超边的初始权重,最后采用PageRank随机游走方法,对要汉越事件素进行评分,最终得到汉越话题要素。实验结果表明,该方法相比只考虑单文本事件要素提取方法的效果有显著提高。     

治安信息五要素智能搜索引擎研究及应用

如何把分散的信息有效组织起来,实现跨部门、跨地区的信息共享,是金盾工程建设必须解决的一个关键问题。主要介绍如何围绕"人、地、物、事件、组织"治安信息五要素的业务模型,利用Web Services、UDDI等技术创建智能搜索引擎,实现全省范围内治安信息五要素关联查询及异构系统间的全网漫游。     

The effect of management structure on the performance of interconnected packet-switched networks

A multi-layer model is used to study the effect of management structure on the performance of connection-oriented packet-switched networks managed via fixed threshold call admission policies. Call admission decisions are based on estimates of the number and characteristics of currently held calls, which may be inaccurate due to uncertainties in the measurement process or to the use of untimely information. Let the state estimate be represented as the true state value offset by a noise factor. The standard deviation of the estimation error serves as a key parameter in representing the complexity, coverage, extensiveness, and cost of the implemented network management and information collection procedure. For a single-domain network the effects of Gaussian noise on blocking, throughput, and the probability of excess calls are examined and used to define a measure of performance, the throughput capacity trajectory, which gives maximum throughput levels for fixed packet blocking, packet delay, and probability of excess call constraints. In a multi-domain network a particular network manager/controller may have complete information about its own domain, but limited, aggregated, or untimely information about other domains. Tradeoffs between centralized and distributed decision-making are discussed and a mechanism is provided for comparing various management structures as well as determining good values for admission control thresholds.     

The effect of fault size on testing

Software fault size (meaning the frequency of activation) is important when determining the merits of different testing methods. One of the purposes of testing is argued to be the identification of faults which, when removed, will contribute increases in reliability. The concept of size-effectiveness is defined here to distinguish those testing methods which are better at finding large faults. Methods of different size-effectiveness can be compared by measuring the distribution of sizes through a measure called the ‘operational testing efficiency ratio’ (OTER). This has significant implications for the way that one should view testing in particular and the software development process in general. © 1997 John Wiley & Sons, Ltd.     

Lateral Conflict Model of Training Flight Based on Subjective Factors

The flight lateral conflict model which is based on human subjective factors has always been a research hotspot for training flight. In order to effectively evaluate the safety interval and lateral collision risk in training airspace, in this paper, pilot subjective factors were modeled. It was studied in lateral conflict risk of low altitude complex flight by flight performance shaping factor. By analyzing flight data of a flight training institution in China, it is pointed that the lateral collision risk in specific training airspace meets the requirement of safety target level of international civil aviation organization. The collision risk of circle procedure and eight characters procedure is 2.9264 × 10⁻¹³ and 3.19232 × 10⁻¹³. The results indicate that the lateral conflict model of training flight based on subjective factors is an effective method to analyze collision risk of low altitude complex flight.     

Effects of modes of cockpit automation on pilot performance and workload in a next generation flight concept of operation

The objective of this study was to compare the effects of various forms of advanced cockpit automation for flight planning on pilot performance and workload under a futuristic concept of operation. A lab experiment was conducted in which airline pilots flew simulated tailored arrivals to an airport using three modes of automation (MOAs), including a control‐display unit (CDU) to the aircraft flight management system, an enhanced CDU (CDU+), and a continuous descent approach (CDA) tool. The arrival scenario required replanning to avoid convective activity and was constrained by a minimum fuel requirement at the initial approach fix. The CDU and CDU+ modes allowed for point‐by‐point path planning or selection among multiple standard arrivals, respectively. The CDA mode completely automated the route replanning for pilots. It was expected that the higher‐level automation would significantly reduce pilot workload and improve overall flight performance. In general, results indicated that the MOAs influenced pilot performance and workload responses according to hypotheses. This study provides new knowledge about the relationship of cockpit automation and interface features with pilot performance and workload in a novel next generation–style flight concept of operation. © 2012 Wiley Periodicals, Inc.     

动态数据校正技术用于GMVC控制器性能评估的改进

在实际工业生产过程中,控制器性能的好坏直接影响了系统的收益;事实上,由于工作环境的复杂性,控制器容易受到各种干扰信号的影响,这通常会导致控制效果不符合预期;因此,对控制器的性能进行评估显得尤为重要;针对反馈系统中测量噪声的干扰问题,分析了测量噪声对基于广义最小方差控制(GMVC)的控制器性能评估(CPA)结果的影响;为了提升CPA的精度,提出了一种动态数据校正(DDR)方法来降低测量噪声对系统性能的影响;首先,在SISO和MIMO系统中引入基于GMVC的CPA;接着讨论了测量噪声对CPA结果的影响;最后,采用DDR滤波器来提升CPA结果的准确性;仿真中系统在不同情况下输出的比较验证了DDR滤波器的良好性能.     

The effect of safety initiatives on safety performance: a longitudinal study

Construction industry is one of the most dangerous industries, not only in the USA, but worldwide. In this longitudinal study we examined the effects of safety initiatives on the safety performance of construction companies. One of the measures commonly used in the USA to track a company's safety performance is the experience modification rate (EMR). The EMR is based on the company's safety records (injury claims) from the past three full years and is used to calculate the workers' compensation insurance premiums. In a longitudinal study, we studied the effects of safety efforts and initiatives on the EMR. The results show that safety initiatives and money spent on safety do improve safety performance, but only over time.