Evaluating camouflage design using eye movement data

This study investigates the characteristics of eye movements during a camouflaged target search task. Camouflaged targets were randomly presented on two natural landscapes. The performance of each camouflage design was assessed by target detection hit rate, detection time, number of fixations on display, first saccade amplitude to target, number of fixations on target, fixation duration on target, and subjective ratings of search task difficulty. The results showed that the camouflage patterns could significantly affect the eye-movement behavior, especially first saccade amplitude and fixation duration, and the findings could be used to increase the sensitivity of the camouflage assessment. We hypothesized that the assessment could be made with regard to the differences in detectability and discriminability of the camouflage patterns. These could explain less efficient search behavior in eye movements. Overall, data obtained from eye movements can be used to significantly enhance the interpretation of the effects of different camouflage design.     

Heart Rate and the Concept of Circulatory Load∗

The functional demands of different types of work-load (dynamic and static muscular work, exposure to extreme hot or cold climates and the mental load caused by emotional stress and by the processing of information) are discussed in this paper. The need for absolute and comparative or relative measurement or estimation of these functional physiological demands in different work situations are considered. The validity of oxygen consumption of the body and of heartrate as an integral ergonomics measure are critically discussed. It is pointed out that these measures have only a high validity when (heavy) dynamic muscular work is considered. However, in muscular work of a static type and in the other type3 of work-load mentioned (climatic and mental conditions) there are many restrictions on their validity

Moreover, from the point of view of occupational medicine and ergonomics there is a need for specific knowledge about the load of different organic (functional) systems. Therefore, the concept of circulatory load is put forward and its value as an ergonomics measure is advocated

The use of heart rate alone as a measure of circulatory load has a rather restricted value. It is shown that the intrinsic value of each heartbeat as a measure of circulatory load differs greatly in different types of work-load, since apart from heart rate stroke-volume and mean blood pressure show various patterns of reaction in those conditions

The possibilities of exact measurement of these data in the practical work situation, however, are still rather limited. Nevertheless, when using heartrate as an ergonomics measure, those additional quantitative data determining the circulatory load and their reactions on different types of work-load should be carefully estimated and taken into account as much as possible     

Zeitschrift für Arbeitswissenschaft Abstracts of papers,Vol 40 (12 NF), Part 2, 1986

Abstract

Vigilance is the ability of an observer to maintain attention for extended periods of time; however, performance tends to decline with time on watch, a pattern referred to as the vigilance decrement. Previous research has focused on factors that attenuate the decrement; however, one factor rarely studied is the effect of social facilitation. The purpose for the present investigation was to determine how different types of social presence affected the performance, workload and stress of vigilance. It was hypothesised that the presence of a supervisory figure would increase overall performance, but may occur at the cost of increased workload and stress. Results indicated that the per cent of false alarm and response times decreased in the presence of a supervisory figure. Using social facilitation in vigilance tasks may thus have positive, as well as, negative effects depending on the dependent measure of interest and the role of the observer.

Practitioner Summary: Social facilitation has rarely been examined in the context of vigilance, even though it may improve performance. Vigilance task performance was examined under social presence. The results of the present study indicated that false alarms and response times decreased in the social presence of a supervisory figure, thus improving performance.     

Effects of computer icons and figure/background area ratios and color combinations on visual search performance on an LCD monitor

This study investigated the effects of figure/background color combinations, the type of computer icon and the figure/background area ratio on visual search performance on a liquid crystal display (LCD) screen. Participants had to search for the target item in a circle stimulus array, which had a diameter of 20 cm and included one target and 19 distracters. Results showed that these three independent variables significantly affected the visual search performance. The search times for EMAIL and SAVE computer icons were significantly shorter than that for a PRINT computer icon. Visual search performance was better for computer icons with a 90% figure/background area ratio than for a 70% ratio. However, no difference in search time between 90% and 50% ratios or between 70% and 50% ratios was observed. Color combinations also significantly affected the visual search performance and white/yellow and white/blue color combinations for the figure/background resulted in better performance than black/blue and black/yellow combinations. However, no difference in search time was observed for participants with and without esthetic training. The implications of the results are applicable to design icons for the interfacing of computers and communication information.     

神经网络结构搜索方法综述

如今,深度学习广泛地应用于生活、工作中的各个方面,给我们带来了极大的便利.在此背景下,需要设计针对不同任务的神经网络结构,满足不同的需求.但是,人工设计神经网络结构需要专业的知识,进行大量的实验.因此,神经网络结构搜索算法的研究显得极为重要.神经网络结构搜索(NAS)是自动深度学习(AutoDL)过程中的一个基本步骤,对深度学习的发展与应用有着重要的影响.早期,一些神经网络结构搜索算法虽然搜索到了性能优越的神经网络结构,但是需要大量的计算资源且搜索效率低下.因此,研究人员探索了多种设计神经网络结构的算法,也提出了许多减少计算资源、提高搜索效率的方法.本文首先简要介绍了神经网络结构的搜索空间,其次对神经网络结构搜索算法进行了全面的分类汇总、分析,主要包括随机搜索算法、进化算法、强化学习、基于梯度下降的方法、基于顺序模型的优化算法,再其次探索并总结了提高神经网络结构搜索效率的方法,最后探讨了目前神经网络结构搜索工作中存在的问题以及未来的研究方向.     

Visual search strategies and eye movements when searching Chinese character screens

Most visual search studies have been restricted to alphanumeric stimulus materials. Research related to scanning patterns of Chinese characters is sparse. This study is an attempt to understand the differences and similarities in visual search of Chinese characters having a varying degree of complexity among Hong Kong Chinese, Mainland Chinese and Chinese reading non-Chinese people. Eighteen participants were tested on Chinese character screens with three layouts (row, column, and uniform separation) and two word complexities (high and low). The 18 participants comprised six Hong Kong Chinese, six Mainland Chinese and six non-native Chinese readers. Performance data and eye movement data were recorded. The percent correct and search time were the two performance measures. A new measure, called HV-ratio was developed to characterize eye movements. The results show that Hong Kong Chinese use predominantly horizontal search patterns while the Mainland Chinese change their search pattern depending on the layout presented. Non-native Chinese readers, on the other hand, do not seem to show any preference on scanning strategy for a given layout. Word complexity did not show any significant effect on search time. Potential reasons for these differences and design implications are discussed.     

Visual and memory search in complex environments: determinants of eye movements and search performance

Previous research on visual and memory search revealed various top down and bottom up factors influencing performance. However, utilising abstract stimuli (e.g. geometrical shapes or letters) and focussing on individual factors has often limited the applicability of research findings. Two experiments were designed to analyse which attributes of a product facilitate search in an applied environment. Participants scanned displays containing juice packages while their eye movements were recorded. The familiarity, saliency, and position of search targets were systematically varied. Experiment 1 involved a visual search task, whereas Experiment 2 focussed on memory search. The results showed that bottom up (target saliency) and top down (target familiarity) factors strongly interacted. Overt visual attention was influenced by cultural habits, purposes, and current task demands. The results provide a solid database for assessing the impact and interplay of fundamental top down and bottom up determinants of search processes in applied fields of psychology. Practitioner Summary: Our study demonstrates how a product (or a visual item in general) needs to be designed and placed to ensure that it can be found effectively and efficiently within complex environments. Corresponding product design should result in faster and more accurate visual and memory based search processes.     

颜色分组对图标视觉搜索效率的影响

为了提高人机界面的交互效率,通过一组图标搜索实验,采用被试内和被试间混合设计的方法,考察颜色、分组方式以及面板方向对视觉搜索效率的影响.实验主要包括反应时间和正确率,并对二者进行描述性统计分析和方差分析,实验结果表明,利用颜色进行分组面板的视觉搜索效率显著高于单色面板,较大分组方式之间的视觉搜索效率差异不大,但显著高于颜色交替分组方式下的视觉搜索效率;水平方向比垂直方向的视觉搜索效率更高,与水平方向相比,垂直方向下颜色交替出现分组方式的视觉搜索效率更低.     

颜色分组对图标视觉搜索效率的影响

为了提高人机界面的交互效率,通过一组图标搜索实验,采用被试内和被试间混合设计的方法,考察颜色、分组方式以及面板方向对视觉搜索效率的影响.实验主要包括反应时间和正确率,并对二者进行描述性统计分析和方差分析,实验结果表明,利用颜色进行分组面板的视觉搜索效率显著高于单色面板,较大分组方式之间的视觉搜索效率差异不大,但显著高于颜色交替分组方式下的视觉搜索效率;水平方向比垂直方向的视觉搜索效率更高,与水平方向相比,垂直方向下颜色交替出现分组方式的视觉搜索效率更低.     

新一代搜索引擎的研发战略

理想的搜索引擎不仅应该快捷地帮助找到所需要的信息,还应该像银行的窗口一样提供个性化的服务。更进一步,它还应该象专家一样辅助用户做出决策并快速完成各种任务。当前,互联网搜索领域酝酿着前所未有的新机遇。庞大的网民数量为搜索的发展提供了广阔的空间。 社会关系网络和移动互联网推动搜索引擎的技术将会发生重大的改变。自然语言处理对用户意图的理解和对文本的理解能力的提高,将使得搜索的准确性也将持续改善。然而搜索引擎的成功是多方面因素共同作用的结果,需要技术和战略的巧妙配合。该文将深入分析目前搜索引擎技术发展的趋势,指出应该关注的若干重要领域,并且探讨了搜索引擎的研发战略。     

眼动仪与视线跟踪技术综述

文章在回顾视线跟踪技术的研究历程基础上,定义了视线跟踪的基本概念和参数。分析了六种主要视线跟踪技术原理,比较了每种技术的优、缺点。介绍了眼动仪硬件设备的研制和发展状况,对比了几种主要的眼动仪性能。最后,探讨了视线跟踪数据的处理软件和方法,并对视线跟踪技术的应用前景进行总结和展望。     

基于眼动记录与分析技术的测谎研究

为进一步提高测谎的准确度,加快促成测谎结论成为刑事诉讼中的证据,提出一种低成本的将眼睛变化线索用于测谎的方案。首先设计了一种低成本的眼动记录系统记录眼动信号,提出分段加权Hough变换算法跟踪虹膜,利用梯度积分投影函数检测眨眼,采用差分图像估计眼睛张开程度。然后建立了眼动轨迹、眨眼频率及眼睛张开程度等眼动特征与说谎的关系模型。实验取得的眼动特征检测精度证明采用低成本眼动记录系统基本可以满足测谎需求,测谎实验结果证明了本文方法用于测谎或辅助测谎的可行性。     

基于眼动追踪的眼动位置识别

提出了一种基于眼动追踪的眼球运动位置识别方法。眼动线索解读理论指出,通过检测被试者在思考问题时的眼球位置,可以确定人的思考类型。实验数据为测试对象观看屏幕时采集的面部视频,在数据处理过程中将视频解析成一帧一帧的图像,首先基于眼动追踪算法进行人眼定位与跟踪,提取每一帧图像的眼动参数;然后采用粒子群优化的极限学习机来判别眼球运动方向。提出的方法在实际应用环境中有很好的鲁棒性,为眼动线索解读提供了客观的、可靠的位置参数。