结合视觉显著性与眼跳概率模型的视频注视点序列预测

视觉注意力相关研究中,基于图像的视觉显著图预测研究较多,而针对视频的注视点序列预测研究相对较少.在充分考虑视频场景的动态特征与人眼视觉特性基础上,提出了一种同时利用视频底层与高层特征的注视点序列预测模型.使用隐马尔可夫模型(HMM)对注视点的转移序列进行建模,其中注视点的位置作为隐藏状态.首先,采用卷积神经网络(CNN)获得视频的视觉显著图,并将视频帧的显著值作为HMM的观测概率,表征注视点所在区域所能成功引起人视觉注意的程度;然后,使用视觉心理学中基于莱维飞行的眼跳概率模型对HMM状态的转移概率进行建模;最后,通过维特比算法推断整个视频最有可能产生的注视点序列.在HOLLYWOOD2数据集上进行视频的注视点序列预测实验,并和相关算法进行比较.实验结果表明:本文提出的模型的预测结果在Hausdorff距离与平均欧氏距离两项指标上都更优.     

区域管制中注视转移特征

为研究区域管制员在管制过程中的注视转移特征,利用雷达管制模拟机和眼动仪搭建试验平台,设计飞机架次数目(3架、7架)不同的两种模拟管制场景,并划分动态兴趣区,应用马尔可夫链模型分析被试在不同飞机数目下的注视转移特征。结果表明:飞机数量增加后,被试的注视转移范围缩小,且被试当前注视某架飞机时,其下一注视点的注视转移范围仅限某几架飞机之间;而当前注视非飞机区域时,其下一注视点的注视转移范围更广,注意力的分配较前者更为合理。对区域管制员在航班流量较大下注意力分配方面的培训具有重要的参考价值。     

区域管制中注视转移特征研究

为研究区域管制员在管制过程中的注视转移特征,利用雷达管制模拟机和眼动仪搭建试验平台,设计飞机架次数目(3架、7架)不同的两种模拟管制场景,并划分动态兴趣区,应用马尔科夫链模型分析被试在不同飞机数目下的注视转移特征。结果表明：飞机数量增加后,被试的注视转移范围缩小,且被试当前注视某架飞机时,其下一注视点的注视转移范围仅限某几架飞机之间;而当前注视非飞机区域时,其下一注视点的注视转移范围更广,注意力的分配较前者更为合理。本研究对区域管制员在航班流量较大时注意力分配方面的培训具有重要的参考价值。     

ASD儿童平滑追踪任务中注视点间距的筛查价值

为了探讨ASD儿童在平滑追踪任务中双眼注视点间距的鉴别诊断价值,选择ASD儿童和正常儿童各20名,让他们观看平滑追踪任务,收集双眼注视点位置指标,应用多维尺度分析的方法对双眼注视点间距进行三维拟合.结果发现:(1)ASD儿童双眼注视点间距显著大于正常儿童;(2)能够在三维空间中对ASD与TD的DBGP进行很好的区分;(3)在观看150像素的大振幅、4.5°/s快速运动的双眼注视点间距具有优良的鉴别力.ASD儿童追踪动态目标运动的双眼视觉缺陷可能是早期感知觉障碍的诊断指标.     

驾驶人注视点分布对预瞄时间求解精度的影响分析

预瞄是驾驶人模型中的重要环节,预瞄时间的准确性决定了驾驶人模型乃至整个模型的稳定性与精确性.为探究驾驶人注视点分布集中程度对预瞄时间求解精确度的影响.利用眼动仪采集驾驶人眼动数据,对驾驶人眼动数据进行处理得到注视点.利用注视点百分比表征驾驶人注视点分布集中程度,利用预瞄时间置信区间长度表征预瞄时间准确度.探究不同路段上的驾驶人注视点集中程度与预瞄时间求解精度之间的关系.研究表明：不同路段上,当注视矩阵中的元素大于一定值时,预瞄时间的置信区间长度在一定范围之内波动,同时在行驶过程中,驾驶人注视点集中程度越高,注视区域越固定,预瞄时间的求解精度越高.     

彩色路面环境下隧道视觉诱导性评价

为提高彩色路面环境下隧道行车安全性,构建视觉诱导仿真及眼动实验平台,获取注视和扫视行为的眼动参数,在此基础上,提出注视点分布的莫兰指数、扫视时间加权的扫视幅度和基于瞳孔面积变化率的不舒适时间比例等3个彩色路面环境下隧道视觉诱导性评价指标模型,进而给出基于K-means聚类的视觉诱导性评价方法. 最后利用黄、红、绿、蓝、灰、白和黑等7种路面颜色色系,进行实例隧道视觉诱导性评价,并用基于语义差别法的主观评价进行成果验证. 结果表明：在提升隧道视觉诱导性方面,黄、红色系路面较优,灰、黑色系路面较差,而绿、蓝、白色系路面根据色彩红绿蓝（RGB）数值呈现一定随机优劣性;该评价技术具有一定的有效性,有助于优选隧道路面颜色,提高驾驶舒适性.     

基于马尔可夫链的驾驶人视觉转移特征

为了不割裂视觉转移过程的连续性,运用动态聚类方法,对驾驶人注视点的视野平面解析坐标进行聚类,实现驾驶人注视区域划分。在考虑驾驶人注视行为在时间轴上关联性的基础上,分析驾驶人注视行为在各注视区域间转移模式的齐次性,运用马尔可夫链理论,探讨各注视区域间视觉转移概率的求解方法,并对5名不同驾驶经验驾驶人的眼动数据进行统计,求得其一步转移概率矩阵和平稳分布,分析驾驶人视觉转移特征。分析结果表明：驾驶人对任一注视目标都需要多次重复注视才能获取足够的信息,且注视点主要集中在前方车道远处、前方车道近处、右侧车道和左侧车道4个区域。     

融合注视点预测和流形学习的显著性目标分割

针对现有显著性分割算法在图像背景复杂时先验知识不够健壮的问题,提出一种融合注视点预测和流形学习的显著性目标分割算法,能有效地对复杂场景中的显著性目标进行分割.该算法通过引入注视点先验知识和提取超像素分割图,预测并粗分割场景中的显著性目标;为了进一步提高显著性分割的性能,利用色彩模型(CIE-Lab)空间的颜色对比度表示超像素的特征;通过基于流形学习的方法对粗分割区域进行显著性优化,提高了分割精度.实验结果表明:在处理复杂图像集过程中,相比其他分割算法,该算法性能提高了21.8%,并且在不同环境下的显著性目标分割的鲁棒性更好.     

基于超复数小波和图像空域的卷积网络融合注视点预测算法

针对已有注视点预测模型存在特征细节缺失、尺度单一和背景信息干扰严重导致的注视点预测精度偏低等问题,提出了一种基于超复数小波和图像空域的卷积网络融合注视点预测算法.首先,针对细节特征丢失问题,使用超复数小波变换在频域中提取图像的细节特征,与卷积网络提取的空域特征进行融合.然后,通过空洞空间金字塔池化模块,融合不同感受得到的特征图,有效解决了特征尺度单一的问题.最后,引入了残差卷积注意力模块,结合空间和通道的注意力机制,能够有效抑制背景信息的干扰,提高注视点预测精度.在SALICON数据集上,CC、sAUC和SIM评价指标下,该算法的性能达到0.884 7、0.769 3和0.778 0;在CAT2000数据集上,该算法在相应指标下的性能为0.735 5、0.870 1和0.664 5.主客观对比实验结果表明,该算法具有较好的注视点预测能力.     

扇区流量分配方式对管制员情景意识的影响探究

随着市场经济的不断发展和人民生活水平的显著提高,越来越多的人选择乘坐飞机出行,我国航空需求量大大增加,其航空安全问题也备受关注。据不完全统计,现阶段,航空不安全事件的发生与大部分空中交通管制员的情境意识下降有关,所以空中交通管制员的情境意识对预防航空不安全事件具有重要影响。该文主要选择了10名管制学员作为被试,在雷达管制模拟机上进行区域管制模拟实验,利用Tobii X2-60眼动仪记录他们的眼动行为数据。通过分析注视点百分比、注视时间百分比、注视点的平均注视时间、平均瞳孔尺寸和平均扫视幅度5个眼动指标,探究扇区流量分配方式对管制员的情景意识的影响。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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