The role of working memory in visual selective attention

The hypothesis that working memory is crucial for reducing distraction by maintaining the prioritization of relevant information was tested in neuroimaging and psychological experiments with humans. Participants performed a selective attention task that required them to ignore distractor faces while holding in working memory a sequence of digits that were in the same order (low memory load) or a different order (high memory load) on every trial. Higher memory load, associated with increased prefrontal activity, resulted in greater interference effects on behavioral performance from the distractor faces, plus increased face-related activity in the visual cortex. These findings confirm a major role for working memory in the control of visual selective attention.     

Modulation of oscillatory neuronal synchronization by selective visual attention

In crowded visual scenes, attention is needed to select relevant stimuli. To study the underlying mechanisms, we recorded neurons in cortical area V4 while macaque monkeys attended to behaviorally relevant stimuli and ignored distracters. Neurons activated by the attended stimulus showed increased gamma-frequency (35 to 90 hertz) synchronization but reduced low-frequency (<17 hertz) synchronization compared with neurons at nearby V4 sites activated by distracters. Because postsynaptic integration times are short, these localized changes in synchronization may serve to amplify behaviorally relevant signals in the cortex.     

Modulation of human visual cortex by crossmodal spatial attention

A sudden touch on one hand can improve vision near that hand, revealing crossmodal links in spatial attention. It is often assumed that such links involve only multimodal neural structures, but unimodal brain areas may also be affected. We tested the effect of simultaneous visuo-tactile stimulation on the activity of the human visual cortex. Tactile stimulation enhanced activity in the visual cortex, but only when it was on the same side as a visual target. Analysis of effective connectivity between brain areas suggests that touch influences unimodal visual cortex via back-projections from multimodal parietal areas. This provides a neural explanation for crossmodal links in spatial attention.     

能见度FD12自动观测与人工观测对比分析

通过对2011年青岛能见度FD12观测仪与人工观测资料进行统计,对比分析两类数据,发现自动观测记录与人工观测记录在能见度2.0km以下时,一致性较好,5.0km以上时,两者观测存在较大的差异。     

Selective attention gates visual processing in the extrastriate cortex

Single cells were recorded in the visual cortex of monkeys trained to attend to stimuli at one location in the visual field and ignore stimuli at another. When both locations were within the receptive field of a cell in prestriate area V4 or the inferior temporal cortex, the response to the unattended stimulus was dramatically reduced. Cells in the striate cortex were unaffected by attention. The filtering of irrelevant information from the receptive fields of extrastriate neurons may underlie the ability to identify and remember the properties of a particular object out of the many that may be represented on the retina.     

Neural mechanisms of visual attention: how top-down feedback highlights relevant locations

Attention helps us process potentially important objects by selectively increasing the activity of sensory neurons that represent the relevant locations and features of our environment. This selection process requires top-down feedback about what is important in our environment. We investigated how parietal cortical output influences neural activity in early sensory areas. Neural recordings were made simultaneously from the posterior parietal cortex and an earlier area in the visual pathway, the medial temporal area, of macaques performing a visual matching task. When the monkey selectively attended to a location, the timing of activities in the two regions became synchronized, with the parietal cortex leading the medial temporal area. Parietal neurons may thus selectively increase activity in earlier sensory areas to enable focused spatial attention.     

Visual attention in the tree shrew: an ablation study of the striate and extrastriate visual cortex

Removal of the striate area in tree shrews results in increased distractibility, which prevents the animals from learning to discriminate form when hue is an irrelevant and distracting cue. Removal of the extrastriate visual cortex results in the reciprocal deficit: an increase in perseveration manifested by an inability to shift attention when irrelevant dimensions are made relevant.     

基于模糊技术的电控自动变速箱故障诊断专家系统研究

针对目前电控自动变速箱在诊断维修过程中存在的问题,把模糊技术和多媒体技术相结合,在Windows环境下研制出电控自动变速箱故障诊断系统.该系统经多种变速箱的使用,结果表明具有推理过程简单、快捷和准确等优点.     

Fusion of the YOLOv4 network model and visual attention mechanism to detect low-quality young apples in a complex environment

Precision Agriculture - The accurate detection of young fruits in complex scenes is of great significance for automatic fruit growth monitoring systems. The images obtained in the open orchard...     

水稻自动调节与产量

在密、稀、超稀和极端稀植群体中 ,初步研究了水稻群体条件下的个体自动调节与分蘖生长、干物质生产和产量形成的关系。研究结果表明 ,水稻在一定的密度范围内具有很强的调节能力 ,生育初期的调节能力较小 ,随着群体系统的不断发展调节能力逐步增强。提高光合势和净同化率有利于增加产量。施肥量、密度与产量分别呈显著水平 ,二者互作效应不显著。群体的产量因素可相互调节 ,稀植条件下单位面积穗数减少 ,千粒重和成熟度增高 ,克服了密植条件下千粒重和成熟度低的不利影响     

粉碎机筛网破损线阵扫描自动识别系统的设计与实现

根据粉碎物料颗粒特征,构建一种基于线阵光学图像采集技术与皮带同步传送技术相结合的动态扫描检测装置和基于虚拟仪器开发平台LabVIEW的粉碎机筛网破损识别系统。以玉米和小麦2种谷物原料为试验样本,在筛网孔径分别为2、4、6mm条件下,以颗粒平均面积为判别指标,粉碎玉米和小麦的筛网破损平均识别率分别为91.25%、82.50%、96.25%和93.75%、86.25%、78.75%;以颗粒面积变异系数为判别指标,粉碎玉米和小麦的筛网破损平均识别率分别为93.75%、98.75%、97.50%和93.75%、87.50%、96.25%。结果表明,以面积变异系数作为判定筛网破损的判别指标的识别效果优于平均面积的识别效果,所构建的自动识别系统可以实现对粉碎机破损筛网的实时自动识别。     

图书馆自动化系统与校园网建设

概述了图书馆自动化系统与校园网建设的关系，并结合本院图书馆的实际情况，介绍了图书馆自动化接入校园网后所能提供的服务内容以及管理方式。     

山楂自动去核机设计及仿真

针对山楂去核作业劳动强度大、不卫生等问题,设计了流水线式山楂自动去核机。分析了山楂特性,山楂内、外径与果核大小的对应关系,为去核刀具设计提供了依据。同时,介绍了山楂自动去核机工作原理,对其关键技术进行研究。运用MATLAB对气压系统进行了仿真,仿真结果表明:去核刀具运动快速,定位精确。     

自动化茶叶炒干机的设计与性能试验

针对目前茶机炒茶不均匀、炒干后茶叶碎茶率较高、品质不佳等问题,设计了一种自动化茶叶炒干机。在阐述机器工作原理的基础上,根据理论计算确定炒干装置关键部件的结构参数,在此基础上对样机进行制作。为进一步探究自动化茶叶炒干机工作时的最佳工作参数,以茶叶在炒干装置内运动速度、分离比、茶叶温升速率为指标,通过离散元仿真软件EDEM分析翻草筋数量、各工作参数对于炒干机炒干效果的影响。利用Design-Expert软件进行回归分析和响应曲面分析,并进行验证实验,确立炒干性能的最佳参数组合为：滚筒转速为19 r·min^-1,炒干温度为184 ℃,炒干时间为80 min,此时平均含水率为5.47%,碎茶率为1.82%。该设计满足茶叶加工工艺要求,并为茶叶炒干机推广应用提供技术参考。     

Discriminative control of "attention"

Three pigeons were trained to discriminate between two tones differing in frequency in the presence of light of one color (A), and not to discriminate between the tones in the presence of light of another color (B). Generalization functions that were determined in the presence of light A showed control of behavior by the frequency of the tone; those determined in the presence of light B did not.     

Increased attention enhances both behavioral and neuronal performance

Single cells were recorded from cortical area V4 of two rhesus monkeys (Macaca mulatta) trained on a visual discrimination task with two levels of difficulty. Behavioral evidence indicated that the monkeys' discriminative abilities improved when the task was made more difficult. Correspondingly, neuronal responses to stimuli became larger and more selective in the difficult task. A control experiment demonstrated that changes in general arousal could not account for the effects of task difficulty on neuronal responses. It is concluded that increasing the amount of attention directed toward a stimulus can enhance the responsiveness and selectivity of the neurons that process it.     

管道自动焊装备发展现状及前景展望

随着高钢级、大口径、大壁厚管道的建设,以及对油气管道运行安全和环境保护要求的日益提高,传统的手工焊和半自动焊已不能满足施工质量和效率的要求,自动焊技术开始大面积推广应用。自动焊技术是基于坡口、组对、焊接于一体的管道施工技术,采用液压传动技术、机械制造技术、自动控制技术结合焊接工艺,完成现场管口的焊接任务,其焊接质量和焊接效率的稳定性在流水施工作业过程中优势明显。系统介绍了自动焊技术特点,阐述了国内外管道坡口机、内焊机、外焊机以及自动焊技术的发展现状,并对未来自动焊装备的发展趋势进行了展望。