共查询到20条相似文献,搜索用时 0 毫秒
1.
Ji-Shen Zheng Jun Liang Wei-Wei Shi Ying Li Hong-Gang Hu Chang-Lin Tian Lei Liu 《科学通报(英文版)》2021,(15):1542-1549
A mirror-image protein-based information barcoding and storage technology wherein D-amino acids are used to encode information into mirror-image proteins that a... 相似文献
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Calford MB Chino YM Das A Eysel UT Gilbert CD Heinen SJ Kaas JH Ullman S 《Nature》2005,438(7065):E3; discussion E3-E3; discussion E4
Any analysis of plastic reorganization at a neuronal locus needs a veridical measure of changes in the functional output--that is, spiking responses of the neurons in question. In a study of the effect of retinal lesions on adult primary visual cortex (V1), Smirnakis et al. propose that there is no cortical reorganization. Their results are based, however, on BOLD (blood-oxygen-level-dependent) fMRI (functional magnetic resonance imaging), which provides an unreliable gauge of spiking activity. We therefore question their criterion for lack of plasticity, particularly in the light of the large body of earlier work that demonstrates cortical plasticity. 相似文献
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传统的任务分配一般是基于环境确定和所有Agent均他利的假设,而实际环境往往是复杂的,复杂环境下的Agent更趋理性和自利,所有这些问题给传统的任务分配带来了障碍.基于Agent理性自利的假设,提出了一种重连策略FriendFind并进行了相关实验,实验表明该算法有效的解决了上述问题. 相似文献
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武云飞 《湖南文理学院学报(自然科学版)》2021,33(1):15-19
为了有效解决传统方法存在测试延时较长、测试误差以及测试成本较高等问题,提出一种多模态智慧网络信息云存储安全等级测试方法.首先组建多模态智慧网络信息云存储安全等级测试体系,选择测试体系中的测试指标作为多模态智慧网络信息安全存储的影响因子.然后利用权重归一化处理方法和指标隶属函数模型,获取各项定性指标的等级赋边界值.最后结合单因素模型评价,组建云存储安全等级测试模型完成测试.仿真实验结果表明,所提方法能够有效降低测试延时以及测试成本,减少测试误差. 相似文献
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为了提高附网存储安全体系的效率,系统分析了附网存储平台上入侵检测技术学习瓶颈的形成机制,发现学习成本随着"知识"的增加呈指数增长,学习瓶颈的存在严重制约了附网存储入侵检测系统的功效。对此提出了一种基于信息融合技术的附网存储安全体系,利用D-S证据理论融合了两种不同的入侵检测技术,包括基于主机系统调用的入侵检测和基于存储... 相似文献
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刘华成 《渝州大学学报(自然科学版)》2008,25(1):38-41
在开发C/S和B/S模式的数据库管理程序时,涉及的图像处理一直是设计人员所面临的难点问题;结合数据窗口对象内嵌的OLE Database Blob,文件操作函数FileRead( )、File-Write( ),SQL语句,以及Windows API函数,提出了一种动态存储与动态载入图像信息的方法;通过将图像信息以大二进制数的形式存储在数据库中.客户端可调用动态SQL语句SelectBlob、UpdateBlob实现从数据库服务器上动态提取和更新图像信息;同时,利用从数据库中提取出的大二进制数图像信息动态创建图像文件,分析并解决了图像在数据窗口对象中的动态载入问题,使得系统具有良好的可移植性。 相似文献
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面向对象的特点之一是抽象,通过提升抽象级别能够构造更强大、更复杂的系统。而采用UML建模能够把复杂的系统用可视化的语言直观地描述出来,使得用户更易理解,后期更易维护。以储值卡收银管理信息系统的开发为背景,探讨了UML在系统中的建模过程。实践表明统一建模语言能极大地提高系统的开发效率和成功率。 相似文献
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应用扫描电镜和蛋白银染色对冠突伪尾柱虫有性周期中第一和第二次皮膜改组时新纤毛器原基的发生、定向和定位进行了观察,并对其发生机制作了初步探讨 相似文献
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Observation of coherent optical information storage in an atomic medium using halted light pulses 总被引:36,自引:0,他引:36
Electromagnetically induced transparency is a quantum interference effect that permits the propagation of light through an otherwise opaque atomic medium; a 'coupling' laser is used to create the interference necessary to allow the transmission of resonant pulses from a 'probe' laser. This technique has been used to slow and spatially compress light pulses by seven orders of magnitude, resulting in their complete localization and containment within an atomic cloud. Here we use electromagnetically induced transparency to bring laser pulses to a complete stop in a magnetically trapped, cold cloud of sodium atoms. Within the spatially localized pulse region, the atoms are in a superposition state determined by the amplitudes and phases of the coupling and probe laser fields. Upon sudden turn-off of the coupling laser, the compressed probe pulse is effectively stopped; coherent information initially contained in the laser fields is 'frozen' in the atomic medium for up to 1 ms. The coupling laser is turned back on at a later time and the probe pulse is regenerated: the stored coherence is read out and transferred back into the radiation field. We present a theoretical model that reveals that the system is self-adjusting to minimize dissipative loss during the 'read' and 'write' operations. We anticipate applications of this phenomenon for quantum information processing. 相似文献
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健康组织和肿瘤组织具有不同的代谢,结构和热力学特性.脑瘤的代谢和结构无序性导致其有较高的熵产生.两种组织不同的熵产生决定了熵由癌流向健康组织.脑瘤和正常细胞在熵和能量方面的差异诱发皮层不同的脑电信号.研究了28个脑瘤患者的脑电图并和健康人进行比较,观察到脑瘤患者脑电图频率的降低.多数情况中慢alpha和theta波出现在肿瘤投影区,此可能与其高熵产生和向外的熵流有关.研究认为,脑瘤的持续高熵产生和热耗散及其它物理效应使得皮层电产生慢化,从而使肿瘤及其邻近的脑组织显示出频率较低的电活性. 相似文献
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三束储存与电子同步运动的动力学稳定性 总被引:1,自引:0,他引:1
近年来,多束存储的动力学稳定性问题一直是人们关注的一个重要问题.本文考虑了频率扰动和运动阻尼的影响,引入高阶相移因子把粒子同步运动方程化为广义Duffing方程.用摄动法导出了系统的近似解,并分析了系统在?/??1/2,1/3共振线附近的运动行为.揭示了系统跳跃现象和临界特征,讨论了系统的数学稳定性和物理稳定性.结果表明,系统稳定性与它的参数有关,只需适当调节这些参数就可以保证系统是稳定的. 相似文献
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Decision making in an uncertain environment poses a conflict between the opposing demands of gathering and exploiting information. In a classic illustration of this 'exploration-exploitation' dilemma, a gambler choosing between multiple slot machines balances the desire to select what seems, on the basis of accumulated experience, the richest option, against the desire to choose a less familiar option that might turn out more advantageous (and thereby provide information for improving future decisions). Far from representing idle curiosity, such exploration is often critical for organisms to discover how best to harvest resources such as food and water. In appetitive choice, substantial experimental evidence, underpinned by computational reinforcement learning (RL) theory, indicates that a dopaminergic, striatal and medial prefrontal network mediates learning to exploit. In contrast, although exploration has been well studied from both theoretical and ethological perspectives, its neural substrates are much less clear. Here we show, in a gambling task, that human subjects' choices can be characterized by a computationally well-regarded strategy for addressing the explore/exploit dilemma. Furthermore, using this characterization to classify decisions as exploratory or exploitative, we employ functional magnetic resonance imaging to show that the frontopolar cortex and intraparietal sulcus are preferentially active during exploratory decisions. In contrast, regions of striatum and ventromedial prefrontal cortex exhibit activity characteristic of an involvement in value-based exploitative decision making. The results suggest a model of action selection under uncertainty that involves switching between exploratory and exploitative behavioural modes, and provide a computationally precise characterization of the contribution of key decision-related brain systems to each of these functions. 相似文献
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COUPLAND RE 《Nature》1955,175(4448):211-212
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双均衡的集群存储资源映射方法 总被引:1,自引:0,他引:1
为了解决集群存储环境下的存储资源管理问题,提出一种双均衡的集群存储资源映射方法。该方法包含两个阶段:第一阶段基于LPT(longest processing time)算法求解集合划分问题,实现将虚拟存储资源请求均匀地分配到节点上;第二阶段基于Toyoda算法求解多维背包问题,用于进行节点内部设备级别的资源映射。这种两阶段的求解过程可以极大地简化集群存储资源映射问题的求解难度,并达到节点间负载均衡和节点内部多维度资源使用均衡的双均衡目标。模拟实验表明该方法不仅达到双均衡的资源映射目标,而且对不同维度、不同粒度的资源请求情况具有良好的适应性。 相似文献
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本文简单论述了信息在传播过程时的增益、受众对信息的选择以及信息价值在传播过程中的变化情况.指出在现代社会,信息在传播过程中会出现信息的增益效应;随着信息流量的大量增加,一方面增加了受众对信息的选择机会,但同时也增加了受众对信息的选择难度;信息价值在传播过程中,因传播速度、时间和空间的改变而发生改变. 相似文献
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本文简单论述了信息在传播过程时的增益、受众对信息的选择以及信息价值在传播过程中的变化情况。指出在现代社会,信息在传播过程中会出现信息的增益效应;随着信息流量的大量增加,一方面增加了受众对信息的选择机会,但同时也增加了受众对信息的选择难度;信息价值在传播过程中,因传播速度、时间和空间的改变而发生改变。 相似文献
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信息传播的增益、信息选择的价值判断和信息价值的传递 总被引:4,自引:2,他引:4
本文简单论述了信息在传播过程时的增益、受众对信息的选择以及信息价值在传播过程中的变化情况.指出在现代社会,信息在传播过程中会出现信息的增益效应;随着信息流量的大量增加,一方面增加了受众对信息的选择机会,但同时也增加了受众对信息的选择难度;信息价值在传播过程中,因传播速度、时间和空间的改变而发生改变. 相似文献
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Miyamichi K Amat F Moussavi F Wang C Wickersham I Wall NR Taniguchi H Tasic B Huang ZJ He Z Callaway EM Horowitz MA Luo L 《Nature》2011,472(7342):191-196
In the mouse, each class of olfactory receptor neurons expressing a given odorant receptor has convergent axonal projections to two specific glomeruli in the olfactory bulb, thereby creating an odour map. However, it is unclear how this map is represented in the olfactory cortex. Here we combine rabies-virus-dependent retrograde mono-trans-synaptic labelling with genetics to control the location, number and type of 'starter' cortical neurons, from which we trace their presynaptic neurons. We find that individual cortical neurons receive input from multiple mitral cells representing broadly distributed glomeruli. Different cortical areas represent the olfactory bulb input differently. For example, the cortical amygdala preferentially receives dorsal olfactory bulb input, whereas the piriform cortex samples the whole olfactory bulb without obvious bias. These differences probably reflect different functions of these cortical areas in mediating innate odour preference or associative memory. The trans-synaptic labelling method described here should be widely applicable to mapping connections throughout the mouse nervous system. 相似文献