53 resultados para cognition
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分布式认知理论通过协调人机对话,结合人和计算机各自的优势解决问题,在人机交互研究中扮演了指导者的角色.尽管分布式认知理论支持的资源模型在分析人机交互时取得了成功,但模型存在不能提供复杂用户任务支持、缺乏对模型中元素的准确定义等问题,在一定程度上导致了表现形式上的混乱.使用分布式认知理论构造了扩展资源模型,建立人机交互活动中的动作和表征之间的联系,从而指导界面的设计和实现.扩展资源模型从静态结构和交互策略两个方面对界面交互动作提供支持,在交互中减少人的认知负担.该研究对设计符合人的认知特点的界面具有一定的指导作用.
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人是生命演化的产物。然而由于具有一个超级大的大脑和高级的认知能力, 人类在自然界中又显得十分与众不同。在灵长类进化过程中,脑容量大小和认知 能力高低可以明显的分成几个等级,由高到低依次为人类、大猿和其它灵长类。 现在一般认为,人类超级大的大脑的形成是适应性选择(达尔文正选择)的结果。 但人类高级认知的起源一直还是个未解之谜。随着分子进化理论和比较基因组学 的发展,人们有可能从分子进化的角度去探讨高级认知的起源问题,并揭示其遗 传学机制。 本文从两个不同的角度入手,通过对认知相关的候选基因的分子进化研究来 探索高级认知起源的遗传学机制。1. 从表型出发,发现microcephalin 基因跟小 脑症相关。我们推测,该基因可能在人类起源过程中发生一些突变,导致脑容量 增大。2. 比较基因组学方法发现垂体腺苷酸环化酶激活肽(PACAP)前体基因在人 类支系中存在正选择。这类受正选择的神经相关基因可能在进化过程中对认知能 力的提高发挥重要作用。 Microcephalin 基因在人脑的发育过程中起重要作用。导致该基因蛋白质翻译 提前终止的突变,会引起人类小脑症,患者脑容量回复到早期原始人的大小。我 们对人群和12 个非人灵长类物种的microcephalin 基因编码区进行测序。所测的 非人灵长类物种包括大猿、小猿、旧大陆猴和新大陆猴。结果显示,microcephalin 基因在人群中具有较高的多态性。在人群中编码区有22 个多态位点,其中有15 个是错义突变位点。中性检验结果显示,microcephalin 基因的高多态性是人类群 体扩张和达尔文正选择共同作用的结果。灵长类各支系的进化分析表明, microcephalin 基因在大猿的起源过程中受到较强的正选择信号。这正好和小猿向 大猿进化过程中大脑容量急剧增大,认知能力大幅度提高的事实相符。单个氨基 酸编码位点检验显示,microcephalin 基因有五个氨基酸位点在灵长类的进化过程中存在正选择信号。这几个位点可能在灵长类进化和人类起源过程中,对脑容量 的增大和认知能力的提高起到了重要的作用。 PACAP 是一个神经系统中高表达的神经肽,与神经发生和神经信号传导有 关。该基因的氨基酸序列在脊椎动物的进化过程中非常保守,表明PACAP 前体 基因在这一进化历程中受到强烈的功能限制。然而比较序列分析显示,自从人与 黑猩猩分歧以后,人类支系中PACAP 前体基因有明显的加速进化。由于存在强 烈的正选择作用,人类支系的氨基酸替换速率是其它哺乳动物支系的至少7 倍。 PACAP 前体基因中有7 个人类特异的氨基酸改变,而这些氨基酸在从鼠类到大 猿的所有物种中都是保守的。蛋白质结构分析结果显示,人类起源过程中,PACAP 前体基因可能编码一个新的神经肽,并在人脑中具有功能。因此,在人类起源过 程中,PACAP 前体基因发生了适应性的改变,可能对人类认知能力的产生起到 了重要作用。这个新神经肽是否存在及其功能还有待于进一步功能实验的验证。 总之,本文通过分子进化分析,发现了两个在灵长类进化过程中对认知能力 的提高起关键作用的基因(Microcephalin 基因、PACAP 前体基因)。Microcephalin 基因,在1400-1800 万年前,从小猿向大猿的进化过程中,可能对脑容量的增大 和认知能力的提高发挥了重要的作用。PACAP 前体基因则在最近的几百万年内, 现代人的起源过程中,对人脑的形成以及人类高级认知能力的产生可能发挥了重 要的作用。
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A new theoretical model of Pattern Recognition principles was proposed, which is based on "matter cognition" instead of "matter classification" in traditional statistical Pattern Recognition. This new model is closer to the function of human being, rather than traditional statistical Pattern Recognition using "optimal separating" as its main principle. So the new model of Pattern Recognition is called the Biomimetic Pattern Recognition (BPR)(1). Its mathematical basis is placed on topological analysis of the sample set in the high dimensional feature space. Therefore, it is also called the Topological Pattern Recognition (TPR). The fundamental idea of this model is based on the fact of the continuity in the feature space of any one of the certain kinds of samples. We experimented with the Biomimetic Pattern Recognition (BPR) by using artificial neural networks, which act through covering the high dimensional geometrical distribution of the sample set in the feature space. Onmidirectionally cognitive tests were done on various kinds of animal and vehicle models of rather similar shapes. For the total 8800 tests, the correct recognition rate is 99.87%. The rejection rate is 0.13% and on the condition of zero error rates, the correct rate of BPR was much better than that of RBF-SVM.
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A new model of pattern recognition principles-Biomimetic Pattern Recognition, which is based on "matter cognition" instead of "matter classification", has been proposed. As a important means realizing Biomimetic Pattern Recognition, the mathematical model and analyzing method of ANN get breakthrough: a novel all-purpose mathematical model has been advanced, which can simulate all kinds of neuron architecture, including RBF and BP models. As the same time this model has been realized using hardware; the high-dimension space geometry method, a new means to analyzing ANN, has been researched.
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BACKGROUND: Hypoxia and ischemia induce neuronal damage, decreased neuronal numbers and synaptophysin levels, and deficits in learning and memory functions. Previous studies have shown that lycium barbarum polysaccharide, the most effective component of barbary wolfberry fruit, has protective effects on neural cells in hypoxia-ischemia. OBJECTIVE: To investigate the effects of Naotan Pill on glutamate-treated neural cells and on cognitive function in juvenile rats following hypoxia-ischemia. DESIGN, TIME AND SETTING: The randomized, controlled, in vivo study was performed at the Cell Laboratory of Lanzhou University, Lanzhou Institute of Modern Physics of Chinese Academy of Sciences, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from December 2005 to August 2006. The cellular neurobiology, in vitro experiment was conducted at the Institute of Human Anatomy, Histology, Embryology and Neuroscience, School of Basic Medical Sciences, Lanzhou University, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from March 2007 to January 2008. MATERIALS: Naotan Pill, composed of barbary wolfberry fruit, danshen root, grassleaf sweetflag rhizome, and glossy privet fruit, was prepared by Gansu Provincial Rehabilitation Center, China. Rabbit anti-synaptophysin, choline acetyl transferase polyclonal antibody, streptavidin-biotin complex kit and diaminobenzidine kit (Boster, Wuhan, China), as well as glutamate (Hualian, Shanghai, China) were used in this study. METHODS: Cortical neural cells were isolated from neonatal Wistar rats. Neural cell damage models were induced using glutamate, and administered Naotan Pill prior to and following damage. A total of 54 juvenile Wistar rats were equally and randomly assigned into model, Naotan Pill, and sham operation groups. The left common carotid artery was ligated, and then rat models of hypoxic-ischemic injury were assigned to the model and Naotan Pill groups. At 2 days following model induction, rats in the Naotan Pill group were administered Naotan Pill suspension for 21 days. In the model and sham operation groups, rats received an equal volume of saline. MAIN OUTCOME MEASURES: Neural cell morphology was observed using an inverted phase contrast microscope. Survival rate of neural cells was measured by MTT assay. Synaptophysin and choline acetyl transferase expression was observed in the hippocampal CA1 region of juvenile rats using immunohistochemistry. Cognitive function was tested by the Morris water maze. RESULTS: Pathological changes were detected in glutamate-treated neural cells. Neural cell morphology remained normal after Naotan Pill intervention. Absorbance and survival rate of neural cells were significantly greater following Naotan Pill intervention, compared to glutamate-treated neural cells (P < 0.05). Synaptophysin and choline acetyl transferase expression was lowest in the hippocampal CA1 region in the model group and highest in the sham operation group. Significant differences among groups were observed (P < 0.05). Escape latency and swimming distance were significantly longer in the model group compared to the Naotan Pill group (P < 0.05). CONCLUSION: Naotan Pill exhibited protective and repair effects on glutamate-treated neural cells. Naotan Pill upregulated synaptophysin and choline acetyl transferase expression in the hippocampus and improved cognitive function in rats following hypoxia-ischemia.
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药物滥用是一种慢性、复发性脑疾病,有着极其复杂的机理。其核心特征是强制性觅药和用药行为,即成瘾者失去了对药物寻求和使用行为的控制。大量的实验证据表明,药物滥用会导致认知功能的损伤和认知偏差,并会造成情绪的异常,这可能是药物滥用和复吸的原因。 本论文的目的在于进一步研究药物滥用对认知和情绪的影响及其相关的脑机制,为此我们首先利用一系列神经心理学的测试,包括简单反应时、选择反应时、快速序列视觉呈现和左右分辨测试,研究了阿片类物质滥用对认知功能(如信息处理能力、注意的时间特性、左右分辨能力等)和情绪反应的影响,并探讨了性别、戒断时间、成瘾历史和开始成瘾的年龄的相关作用。研究结果发现:1)海洛因依赖的病人在上述测试中均表现出明显的功能损伤。2)海洛因依赖的病人对成瘾相关的刺激存在认知偏差,如,在快速序列视觉呈现测试中,他们只在中性词语和负性词语上表现出扩大了的注意瞬脱,但是在成瘾相关词语上的表现与正常被试没有显著差异。3)海洛因依赖病人的情绪反应发生了改变:他们对负性词语的唤起度评分低于中性词语和成瘾相关词语,并小于正常被试对负性词语的唤起度评分;另一方面在快速序列视觉呈现测试中,情绪刺激对海洛因依赖病人的注意瞬脱的影响程度小于正常被试的情况。4)在海洛因依赖病人中发现的认知功能的损伤和认知偏差存在性别差异,女性病人认知功能的损伤程度较男性病人更为严重,并且认知偏差也较男性病人更为明显。5)对于不同的测试,戒断时间、成瘾历史和开始成瘾的年龄有不同的影响。本部分研究较为系统的揭示了药物滥用对于认知和情绪的影响及其特点。 为了进一步研究阿片类物质滥用对认知功能和情绪反应的影响机制,我们利用脑电和功能核磁共振成像,分别研究了吗啡成瘾过程中前额叶的两个主要部分(腹侧前额叶和背外侧前额叶)的变化情况以及海洛因依赖病人的杏仁核对成瘾无关的情绪刺激的反应。结果发现吗啡对腹侧前额叶和背外侧前额叶的脑电活动都造成了一定的影响,并且对脑电γ段的影响在给药后12小时仍然存在,这可能是药物滥用造成认知功能损伤的原因。另外,海洛因依赖病人的左侧杏仁核对情绪刺激的反应小于正常被试,尤其是对正性刺激的反应。这解释了药物滥用者存在情绪异常问题的原因。本部分研究在一定程度上解释了药物滥用对认知和情绪的影响机制,并为前额叶和杏仁核在药物滥用中所起的作用提供了进一步的证据。
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Inspired by human visual cognition mechanism, this paper first presents a scene classification method based on an improved standard model feature. Compared with state-of-the-art efforts in scene classification, the newly proposed method is more robust, more selective, and of lower complexity. These advantages are demonstrated by two sets of experiments on both our own database and standard public ones. Furthermore, occlusion and disorder problems in scene classification in video surveillance are also first studied in this paper.
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Watermarking aims to hide particular information into some carrier but does not change the visual cognition of the carrier itself. Local features are good candidates to address the watermark synchronization error caused by geometric distortions and have attracted great attention for content-based image watermarking. This paper presents a novel feature point-based image watermarking scheme against geometric distortions. Scale invariant feature transform (SIFT) is first adopted to extract feature points and to generate a disk for each feature point that is invariant to translation and scaling. For each disk, orientation alignment is then performed to achieve rotation invariance. Finally, watermark is embedded in middle-frequency discrete Fourier transform (DFT) coefficients of each disk to improve the robustness against common image processing operations. Extensive experimental results and comparisons with some representative image watermarking methods confirm the excellent performance of the proposed method in robustness against various geometric distortions as well as common image processing operations.
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本文以具有典型特征的苏北淤泥质潮滩海岸作为研究区,利用1975-2003年间14景覆盖该地区的Landsat和SPOT卫星影像作为主要数据源,结合地面调查和验证工作,在遥感影像处理和地理信息系统分析技术的支持下,对区内潮滩、岸线、水边线和盐沼植被等进行遥感解译,分析苏北辐射沙脊群和沿岸地貌的空间分布特征和动态演变趋势。研究结果表明:苏北辐射沙脊群海域的潮汐水位过程的不同步现象普遍存在,限制了常规遥感数据在苏北潮滩地貌研究中的适用范围和解译精度;在人工判别的辅助下,多光谱遥感的非监督分类方法可以有效解译淤泥质潮滩的水边线;利用修改型土壤调整植被指数(MSAVI)可以较好地提取潮滩上的盐沼植被信息;苏北沿岸潮滩的快速淤长促进了盐沼植被带向海侧快速扩展,近年来持续的潮滩围垦工程则不断从陆侧侵占盐沼植被带,使盐沼植被带宽度减小乃至消失;在大规模人类活动和自然条件的共同影响下,苏北辐射沙脊群海岸的岸线发育趋于平直化,无序的潮滩围垦项目使得可垦滩地资源被过度消耗;1975~2002年间,研究区北部和南部沿岸的高潮滩整体上处于淤长状态,中部沿岸潮滩和离岸沙洲高潮滩则被大面积侵蚀;1999年以来,研究区内低潮滩部位开始形成有序排列的滩面地物,并表现出逐年大面积蔓延的趋势,可能是滩涂紫菜养殖区扩展的结果。
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根据心理物理学、神经生理学、认知神经学等学科在视觉认知领域的部分研究成果,结合机器视觉、图像处理领域在图像增强方面已经提出的一些方法,提出了结合先验知识的多窗口结构下的分块中值滤波方法,在每一个窗口内单独进行处理与分析,突出了视觉处理目的,减少了运算量, 节省数据存储空间,达到了令人满意的滤波效果,能够在原始图像比较复杂的情况下,较好地对其进行预处理,可以改善、提高后期图像处理过程,如图像分割、图像分析的正确性和有效性。
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:本文从信息时代对人们认识上的影响,讨论了信息时代对生产、对统一的世界市场、对社会的影响。列举了世界经济进入新的繁荣期的特征。讨论了世界生产的形成和发展,市场竞争的三准则,市场竞争的各个历史阶段及全球化敏捷制造体系迅速发展的原因。分析了二十一世纪制造业面临的形势。详细地讨论了我国国有大中型企业的主要问题:1.产品问题;2.企业结构不合理;3.管理问题;4.质量问题;5.工艺手段和装备落后;6.历史包袱沉重等。提出了利用世界全球化生产体系发展的大好形势的三条对策:1.利用敏捷制造原理对企业进行重组;2.加速产品设计队伍的重建,增强新产品的设计能力;3.利用现代化手段实现现代化管理。
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本文初步探讨了遥控机器人监控的基本概念,得出这样一种认识:监控方式是机器人向智能化发展的一个恰当模式,监控系统是由人的高级智能与机器人的低级智能构成的系统.监控是系统中这两种智能相互作用的过程,人的智能应当能够在机器智能的不同级别上输入,我们研制了一个遥控机器人监控操作器的实验系统,通过实例和实验作了说明.
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Groundwater basin is important for water supply in northern China. The paper took the Jingsheng Basin in Lingshi County, Shanxi Province as a case to study the basin groundwater system by numerical modeling. The hydrogeological characteristics were analysed basing on the field investigation, and a three-dimensional groundwater flow model was established to describe the groundwater flow system in the Jingsheng groundwater basin. The boundary of the model was determined by using geophysics and GIS data, and the lumped parameter model of runoff was used to depict the transform between the surface water and groundwater, and the groundwater dating data was used to calibrate the model. All these methods were used to improve the model. The Software Visual MODFLOW 2000 was applied to set up the numerical groundwater flow model. The groundwater flow pattern in the average year, the high-water year and the low-water year were simulated respectively by the model. Some new cognition to the groundwater movement in Jingsheng Basin was obtained in the paper. The difficult problems were resolved when using the conventional and theoretical analysis to forecast and appraise the exploitation of the groundwater, and supplies the instructional technology base for the reasonable exploitation and optimization collocation. The numerical model will improve evaluation of the basin groundwater resources.
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Luo Ning ( Mineralogy, Petrology, Deposit Mineralogy) Directed by Fu Liyun With the increase of the level of exploration and development, North China field, as one of the maturing fields in the east, has gradually turned their prospecting targets to frontiers such as deep zones, lithologic hydrocarbon reservoirs, low permeable layers, special lithostromes, etc, which propose new challenges to mating technique of exploration engineering. In it, the special lithostrome of clay carbonate in Shu-Lu cave in Middle Flank exploration area locates in Es_3 generating rock. The area distribution is large, formation thickness is over 100 meters, the oil accumulation condition is excellent, prognostic reserves is over 80,000,000 tons, but how to effectively stimulate the special low permeable and fractured reservoir has become the bottle neck problem of stimulation and stable yields. In this thesis, through comprehensive evaluation and analysis of lithology, lithomechanics, hydrocarbon reservoir characteristics, the characteristics of fluid flow through porous medium and the stimulation measures in the past, we acquire new cognition of clay carbonate reservoirs, in addition, the research and application of first hydraulic fracturing has gained positive effect and formed commensurable comprehensive reservoir evaluation technique and mating engineering technique of hydraulic fracturing. The main cognitions and achievements are as follows: 1.Study of geological information such as lithololy analysis and nuclear magnetic logging, etc, indicates that clay carbonate formation of Shu-Lu cave is anisotropic, low permeable with high shale content, whose accumulation space gives priority to microcracks. 2.The analysis of lithomechanics of clay carbonate indicates that the hardness is moderate, Young’s modulus is between that of sandstone and limestone, clay carbonate presents plastic property and its breakdown pressure is high because of the deep buried depth. 3.The analysis of the drillstem test curves indicates that the flow and build-up pressure curve of clay carbonate of Shu-Lu cave mainly has three types: formation contamination block-up type, low permeable type, formation energy accumulation slowness type; the reservoir characteristics presents double porosity media, radial compounding, uniform flow vertical fracture, isotropy, moniliform reservoir type. The target well Jingu 3 belongs to moniliform reservoir type. 4.Through recognition and re-evaluation of the treatment effect and technologic limitations of acidizing, acid fracturing and gelled acidizing in the past, based on the sufficient survey and study of hydraulic fracturing home and abroad, combined with comprehensive formation study of target well, we launched the study of the optimization of hydraulic fracturing technique, forming the principal clue and commensurable mating technology aimed at clay carbonate formation, whose targets are preventing leak off, preventing sand bridge, preventing embedment, controlling fracture height, forming long fracture. 5. Recognition of stimulation effect evaluation.