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101.
The present study aims to investigate the neural correlates underlying humans’ sensitivity to valence differences in negative stimuli. Event-related potentials (ERPs) for highly negative (HN), moderately negative (MN), and Neutral pictures were recorded while subjects perform a standard/deviant categorization task, irrespective of the emotional valence of the deviants. The results show more negative ERP deflections during HN condition than during MN condition at each 50 ms interval from 350 to 650 ms after stimulus onset (at P3 and slow negative wave (SNW) components). Moreover, emotional effect was also observed for MN stimuli at P3 component (350—450 ms interval). Dipole analyses on the HN-MN difference wave during 350—450 ms interval (P3 component) and that during 450—650 ms interval (SNW component) were both localized to the right medial temporal lobe. Thus, the present study confirmed the human sensitivity to valence variations in emotionally negative stimuli, and further showed that the right medial temporal lobe, in particular, the right hippocampus/amygdala complex, may be the critical neural substrates underlying humans’ differential sensitivity to emotionally negative stimuli of varying valences. 相似文献
102.
大肠杆菌是常用的基因工程蛋白表达系统宿主菌,而密码子偏倚性常常成为某些异种蛋白质在大肠杆菌中成功表达的障碍.利用含有编码多种稀有tRNA的重组质粒RIG,一个含有大量稀有密码子的人类线粒体转录终止因子样蛋白成功地在大肠杆菌中得到表达.证明使用RIG质粒是克服大肠杆菌密码子偏倚性的有效手段. 相似文献
103.
Regional,individual and political determinants of FOMC members' key macroeconomic forecasts 下载免费PDF全文
We study Federal Open Market Committee members' individual forecasts of inflation and unemployment in the period 1992–2004. Our results imply that Governors and Bank presidents forecast differently, with Governors submitting lower inflation and higher unemployment rate forecasts than bank presidents. For Bank presidents we find a regional bias, with higher district unemployment rates being associated with lower inflation and higher unemployment rate forecasts. Bank presidents' regional bias is more pronounced during the year prior to their elections or for nonvoting bank presidents. Career backgrounds or political affiliations also affect individual forecast behavior. 相似文献
104.
加权半方差风险度量模型 总被引:1,自引:0,他引:1
文章考虑到资产离散程度和投资者的风险爱好,引入风险偏好系数,建立加权半方差风险度量模型;虽然证券价格具有局部突变性,但从长期整体看证券价格的变化具有整体连续变化的基本属性;用“局部积分均值”方法估计证券期望收益率,可以平滑证券价格的突变因素而加强整体变化连续性因素的作用,更能客观反映实际变化的规律。 相似文献
105.
飞轮电池磁悬浮控制系统的仿真和实验研究 总被引:8,自引:0,他引:8
提出了一种用于飞轮电池的电磁和永磁混合磁悬浮轴承设计方案,其轴向位移由电磁铁主动控制,其余自由度由永磁铁以吸力方式给以约束,同时由永磁铁提供电磁控制的偏置磁场。对电磁力和永磁力进行了有限元计算和线性化,建立了磁悬浮控制系统的模型。对系统在不同的PID控制器参数下。受到阶跃扰动力的位移响应进行了仿真。采用上述磁悬浮方案和PID控制器,完成了一个单自由度磁悬浮实验,洲试了飞轮转子轴向脉冲力位移响应.实验结果证实上述磁悬浮方案和控制器能够实现飞轮转子的稳定悬浮。 相似文献
106.
针对一类具有系统建模误差,以及含传感器模型不确定项的非线性控制系统,提出了一种用于执行器故障诊断的观测器方法。观测器中引入自适应补偿项,当出现偏差后将对故障及建模不确定项进行补偿。自适应算法中采用了死区算子,增强了算法的鲁棒性。同时利用自适应律进行偏差估计。理论分析证明观测器的观测误差收敛到零。仿真结果表明了方法的有效性。 相似文献
107.
Lennart Sjberg 《Journal of forecasting》1982,1(4):349-363
Intuitive judgement forms the basis of decision making both by experts, in professional settings, and by people in everyday life. Psychologists have studied the rationality of intuitive judgements. In this paper three approaches to decision making will be discussed: unqualified rationalism, qualified rationalism and irrationalism. The first approach holds that man is essentially rational, the second that serious cognitive biases exist, and the third that thinking is strongly influenced by non-cognitive sources of distortion, i.e. emotions and motives. Evidence on judgement is reviewed and found to support the last two approaches. Various ways of improving judgements, as suggested by the three basic viewpoints, are then presented. 相似文献
108.
状态输入估计两段解耦Wiener滤波器 总被引:3,自引:3,他引:0
运用现代时间序列分析方法,基于ARMA模型和白噪声估值器,对一类控制输入存在不确知性的随机系统,提出了状态输入估计两段解耦Wiener滤波新算法,仿真例子说明了其有效性。 相似文献
109.
Xiufan Shi Jingfei Huang Chongrong Liang Shuqun Liu Jun Xie Ciquan Liu 《科学通报(英文版)》2001,46(12):1015-1019
Synonymous codon bias has been examined in 78 human genes (19967 codons) and measured by relative synonymous codon usage (RSCU). Relative frequencies of all kinds of dinucleotides in 2,3 or 3,4 codon positions have been calculated, and codon-anticodon binding strength has been estimated by the stacking energies of codon-anticodon bases in Watson-Crick pairs. The data show common features in synonymous codon bias for all codon families in human genes: all C-ending codons, which possess the strongest codon-anticodon binding energies, are the most favored codons in almost all codon families, and those codons with medium codon-anticodon binding energies are avoided. Data analysis suggests that besides isochore and genome signature , codon-anticodon binding strength may be closely related to synonymous codon choice in human genes. The join-effect of these factors on human genes results in the common features in codon bias. 相似文献
110.
1. Introduction Robust design (RD) techniques based on the concept of building quality into a design are increasingly popular in industry primarily because of their practicality. There have been many attempts to integrate Taguchi’s RD principles with well-established statistical techniques, such as response surface methodology (RSM), in order to model the response directly as a function of control factors (Vining and Myers 1990). RSM is a collection of mathematical and statistical techni… 相似文献