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1.
Wynne CD 《Nature》2004,428(6979):140; discussion 140
Brosnan and de Waal report that capuchin monkeys show evidence of a sense of fairness or 'inequity aversion' because they rejected a less preferred reward when they saw a partner monkey receive a preferred reward for the same task. However, this does not show that monkeys are averse to inequity, only that they reject a lesser reward when better rewards are available. There are risks inherent in seeking anthropomorphic explanations for non-human behaviour.  相似文献   

2.
Matsumoto M  Hikosaka O 《Nature》2007,447(7148):1111-1115
Midbrain dopamine neurons are key components of the brain's reward system, which is thought to guide reward-seeking behaviours. Although recent studies have shown how dopamine neurons respond to rewards and sensory stimuli predicting reward, it is unclear which parts of the brain provide dopamine neurons with signals necessary for these actions. Here we show that the primate lateral habenula, part of the structure called the epithalamus, is a major candidate for a source of negative reward-related signals in dopamine neurons. We recorded the activity of habenula neurons and dopamine neurons while rhesus monkeys were performing a visually guided saccade task with positionally biased reward outcomes. Many habenula neurons were excited by a no-reward-predicting target and inhibited by a reward-predicting target. In contrast, dopamine neurons were excited and inhibited by reward-predicting and no-reward-predicting targets, respectively. Each time the rewarded and unrewarded positions were reversed, both habenula and dopamine neurons reversed their responses as the bias in saccade latency reversed. In unrewarded trials, the excitation of habenula neurons started earlier than the inhibition of dopamine neurons. Furthermore, weak electrical stimulation of the lateral habenula elicited strong inhibitions in dopamine neurons. These results suggest that the inhibitory input from the lateral habenula plays an important role in determining the reward-related activity of dopamine neurons.  相似文献   

3.
针对评价信息为概率语言术语集,专家权重和属性权重完全未知的多属性群决策问题,提出基于概率语言相关系数的多属性群决策模型.首先定义了概率语言的相关系数并且拓展到概率语言矩阵间的相关系数; 然后基于每个专家的决策矩阵,通过最小化加权相关系数总和求得每个专家的属性权重向量,并且通过决策矩阵的相关系数客观地确定专家权重; 最后将经典的ELECTRE方法加以改进用于方案排序,并且通过算例分析与比较分析证明了该决策方法的有效性与优越性.  相似文献   

4.
Relative reward preference in primate orbitofrontal cortex   总被引:33,自引:0,他引:33  
Tremblay L  Schultz W 《Nature》1999,398(6729):704-708
The orbital part of prefrontal cortex appears to be crucially involved in the motivational control of goal-directed behaviour. Patients with lesions of orbitofrontal cortex show impairments in making decisions about the expected outcome of actions. Monkeys with orbitofrontal lesions respond abnormally to changes in reward expectations and show altered reward preferences. As rewards constitute basic goals of behaviour, we investigated here how neurons in the orbitofrontal cortex of monkeys process information about liquid and food rewards in a typical frontal task, spatial delayed responding. The activity of orbitofrontal neurons increases in response to reward-predicting signals, during the expectation of rewards, and after the receipt of rewards. Neurons discriminate between different rewards, mainly irrespective of the spatial and visual features of reward-predicting stimuli and behavioural reactions. Most reward discriminations reflect the animals' relative preference among the available rewards, as expressed by their choice behaviour, rather than physical reward properties. Thus, neurons in the orbitofrontal cortex appear to process the motivational value of rewarding outcomes of voluntary action.  相似文献   

5.
为解决虚拟机部署过程中对虚拟机性能、资源利用率、负载均衡值等多个目标的优化问题,提出一种基于强化学习的改进部署算法.首先,用多个目标组成的多维奖励代替原来的单一奖励;然后将资源状态、优化目标及目标占比输入所提的预测器中来预测每个部署方案对应的多维奖励值,并通过反馈结果调节不同优化目标的占比以达到动态多目标优化的目的;最后,为了减少部署时间,用改进的均值聚类算法对服务器资源进行聚类加快部署.通过CloudsimPy平台对算法进行验证,结果表明本文算法可以在相同资源下完成更多的虚拟机请求且具有较高的部署成功率和较低的时延消耗.  相似文献   

6.
Representation of a perceptual decision in developing oculomotor commands   总被引:15,自引:0,他引:15  
Gold JI  Shadlen MN 《Nature》2000,404(6776):390-394
Behaviour often depends on the ability to make categorical judgements about sensory information acquired over time. Such judgements require a comparison of the evidence favouring the alternatives, but how the brain forms these comparisons is unknown. Here we show that in a visual discrimination task, the accumulating balance of sensory evidence favouring one interpretation over another is evident in the neural circuits that generate the behavioural response. We trained monkeys to make a direction judgement about dynamic random-dot motions and to indicate their judgement with an eye movement to a visual target. We interrupted motion viewing with electrical microstimulation of the frontal eye field and analysed the resulting, evoked eye movements for evidence of ongoing activity associated with the oculomotor response. Evoked eye movements deviated in the direction of the monkey's judgement. The magnitude of the deviation depended on motion strength and viewing time. The oculomotor signals responsible for these deviations reflected the accumulated motion information that informed the monkey's choices on the discrimination task. Thus, for this task, decision formation and motor preparation appear to share a common level of neural organization.  相似文献   

7.
研究了决策者偏好以三参数区间数型偏好序形式给出的有限方案群决策问题。首先给出了三参数区间数型偏好序的定义,在综合考虑决策者偏好信息的基础上,引入导出的偏好序向量,给出了三参数区间数型偏好序的概率描述。其次介绍了三参数区间数型偏好序一致性的两个定义,利用调整算法对一致性不可接受的偏好序进行修正。通过定义三参数区间数型偏好序之间的偏差函数,给出一种确定决策者权重向量的有效方法,从而建立了一种解决有限方案群决策问题的有效算法。最后通过一个实例说明该方法的可行性和有效性。  相似文献   

8.
提出了一种高分辨率遥感影像中的水运航标提取算法.首先应用单类支持向量机分类器实现水陆分割,确定水陆边界.然后将水域中的小目标作为候选目标,基于目标几何和灰度统计特性进行初步筛选,获得疑似航标目标.再利用影像中航标窗口间的相关性,提出一种基于相关系数编组的航标判定方法.最后提出一种基于在线学习原理的漏检航标检测算法,即首先依据已经检测得到的航标的空间分布对漏检航标的可能位置进行估计,再依据已检测到的航标的先验知识在估计位置进行精确检测.利用QuickBird影像进行的实验结果表明了该方法的有效性.  相似文献   

9.
结构非概率可靠性优化设计   总被引:7,自引:1,他引:7  
在结构质量限制条件下,提出了一个结构非概率可靠性设计的数学模型。数学模型由两个优化过程组成。第一个优化过程是在结构质量约束下极大化结构非概率可靠性。第二个优化过程是在载荷不确定性条件下,考虑结构应力,位移约束和极小化结构质量。其中第二个优化过程嵌套在第一个优化过程之中。作为一个数字算例。用所提出的优化模型进行了一个桁架结构的非概率可靠性优化设计。当关于所有不确定性载荷的信息严重缺乏时,设计者宜采用最小值最大化法则进行结构非概率可靠性优化设计,设计者如何仅对某个不确定性载荷的特性知之甚少而对其他不确定性载荷的波动变化有较好的了解,则可事先确定其他不确定性参数的值而最大化该不确定性参数。  相似文献   

10.
本文提供了机床夹具一面两销定位的概率设计法,给出了计算示例,并进行了计算机模拟。结果表明,当夹具按概率理论设计时,可以降低夹具的精度要求或提高加工精度。  相似文献   

11.
单向变异S-粗集的概率特征   总被引:1,自引:0,他引:1  
利用单向变异S-粗集的结构,给出元素迁移的概率特征:属性集α的下近似概率特征,属性集α的上近似概率特征,利用这些结果,给出单向变异S-粗集的概率特征,提出单向变异S-粗集的随机结构与随机定理.单向变异S-粗集的结构是单向变异S-粗集的随机结构的特例,单向变异S-粗集的随机结构是单向变异S-粗集结构的一般形式.  相似文献   

12.
基于灰色关联度的多目标决策模型与应用   总被引:9,自引:0,他引:9  
基于灰色关联度理论,运用因素的灰色关联度确定指标权重,以方案的加权灰色关联度作为评判准则建立了一种多目标决策模型,并通过实例说明了该模型的实用性和有效性。  相似文献   

13.
J E Smith  C Co  M E Freeman  M P Sands  J D Lane 《Nature》1980,287(5778):152-154
Drugs of abuse probably exert their reinforcing effects through 'reward' pathways in the central nervous system (CNS). Neuronal systems mediating opiate reinforcement have been investigated using pharmacological and electrolytic lesion procedures. Drugs that interfere with catecholaminergic and cholinergic neuronal activity decrease intravenous (i.v.) morphine self-administration in monkeys and rats. Electrolytic lesion procedures in rats have demonstrated that the medial forebrain bundle and caudate nucleus are important in maintaining i.v. morphine self-administration. We have now carried out a direct investigation of striatal (caudate nucleus, putamen and globus pallidus) neuronal systems. We show here that striatal catecholaminergic systems are important in mediating opiate reinforcement, and present direct evidence for the involvement of neurotransmitter systems in morphine reward.  相似文献   

14.
本文基于正切函数提出一种新的直觉模糊正切相似度量,并将其应用在工程方案的多属性决策中。在方案决策中,通过计算理想方案与各备选方案的相似度量值,并按计算的相似度量值作出排序,选出最佳方案。也就是说,计算出的相似度量值越大,方案就越好。应用实例表明了所提直觉模糊正切相似度量决策方法的有效性与合理性。这种决策方法为工程方案的决策提供了新的途径。  相似文献   

15.
基于特征域词频的邮件过滤方法的研究   总被引:1,自引:0,他引:1  
出了根据邮件特征域信息和特征词频进行垃圾邮件过滤的新方法,并介绍在该方法中的文本特征选取、特征词典构造以及基于TF的权值计算等相关技术,以及改进的文本相似度计算概率模型.实验表明该方法在邮件过滤的查全率、查准率等几个性能评价指标上,比传统的Rocchio方法有了明显改善.  相似文献   

16.
Wang  XiaoPing  Jin  Wei  Yu  Li  Zhang  YaPing 《科学通报(英文版)》2010,55(36):4132-4135
Chinese snub-nosed monkeys (genus Rhinopithecus, subfamily Colobinae), including R. bieti, R. brelichi and R. roxellana, are well-known as the non-human primates with the highest known altitudinal distribution. They represent an interesting model organism of adaptation to the extreme environmental stresses. However, no study at the molecular level has yet been reported for the high-altitude adaptation in Chinese snub-nosed monkeys. Leptin, as an adipocyte-derived hormone, is believed to play an important role in energy homeostasis in adaptation to high altitude environments. In the present study, we sequenced and compared leptin sequences of the Chinese snub-nosed monkeys (R. bieti and R. roxellana) with their lowland close relative R. avunculus and other Colobines. Unexpectedly, no amino acid changes were observed in the 7 Colobinae species examined, including the 2 Chinese snub-nosed monkeys, indicating no difference in the evolutionary pattern of the Leptin gene between high-altitude monkeys and their lowland counterparts. In contrast to a previous finding of adaptive evolution of Leptin gene in plateau pikas, our study suggests that this gene may not have an important role in high-altitude adaptation of Chinese snub-nosed monkeys. Other nuclear genes associated with energy metabolism, or mitochondrial genes, are most likely to be involved the molecular mechanism underlying adaptation of these monkeys to cold and hypoxia associated with the highland environment.  相似文献   

17.
Forde SE  Beardmore RE  Gudelj I  Arkin SS  Thompson JN  Hurst LD 《Nature》2008,455(7210):220-223
Given the difficulty of testing evolutionary and ecological theory in situ, in vitro model systems are attractive alternatives; however, can we appraise whether an experimental result is particular to the in vitro model, and, if so, characterize the systems likely to behave differently and understand why? Here we examine these issues using the relationship between phenotypic diversity and resource input in the T7-Escherichia coli co-evolving system as a case history. We establish a mathematical model of this interaction, framed as one instance of a super-class of host-parasite co-evolutionary models, and show that it captures experimental results. By tuning this model, we then ask how diversity as a function of resource input could behave for alternative co-evolving partners (for example, E. coli with lambda bacteriophages). In contrast to populations lacking bacteriophages, variation in diversity with differences in resources is always found for co-evolving populations, supporting the geographic mosaic theory of co-evolution. The form of this variation is not, however, universal. Details of infectivity are pivotal: in T7-E. coli with a modified gene-for-gene interaction, diversity is low at high resource input, whereas, for matching-allele interactions, maximal diversity is found at high resource input. A combination of in vitro systems and appropriately configured mathematical models is an effective means to isolate results particular to the in vitro system, to characterize systems likely to behave differently and to understand the biology underpinning those alternatives.  相似文献   

18.
针对目标批次过多导致计算上的组合爆炸问题,提出一种改进并行集中式多传感器不敏近似联合概率数据关联(joint probabilistic data association,JPDA)算法。该算法首先采用基于unscented变换的卡尔曼滤波(unscented Kalman filter,UKF)实现非线性系统中状态估计的递推,然后通过改进的并行集中式方法将数据传至中心,利用改进的JPDA方法进行量测点迹与目标航迹关联。仿真实验表明,该算法在非线性复杂环境中具有较好的数据关联正确率,且计算耗时较集中式串行不敏JPDA算法少。  相似文献   

19.
基于S-D分配的多传感器联合概率数据互联算法   总被引:1,自引:1,他引:0  
为解决集中式多传感器系统中多目标跟踪问题,提出了一种基于S-D分配的集中式多传感器联合概率数据互联算法。算法首先应用广义S-D分配的规则对每个传感器送来的观测数据进行排列组合,然后对每个组合中各量测点进行概率加权以获得一个等效量测点,最后根据每个等效量测点的联合似然函数计算其联合互联概率并获得融合中心的状态估计。该文最后给出了该算法与已有集中式多传感器联合概率数据互联算法的仿真比较,仿真结果表明该文算法的跟踪性能更优越。  相似文献   

20.
根据非营利组织的特征,本文提出非营利组织主管的报酬由现期报酬和预期报酬两部分组成,现期报酬主要是指货币报酬,同时还包括非营利组织有别于营利组织的工作环境带来的额外的满足感,而预期报酬主要源于主管与社会之间的心理契约;非营利组织理事会在设计主管的报酬时,应充分考虑主管对现期报酬和预期报酬的偏好、现期报酬的效用产出弹性和预期报酬的贴现系数等影响因素.  相似文献   

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