基于特征可分性的核函数自适应构造

核函数的选择与构造是支撑向量机研究中的关键问题和难点.该文针对该问题,首先讨论了特征空间的线性可分性,推导了其判别条件.然后,根据特征完全可分条件,基于函数逼近论和核函数的基本性质,提出了自适应多项式核函数和B-样条核函数模型,给出了模型参数的估计算法.实测数据仿真实验结果表明,与经典的核函数相比,该文提出的算法在分类性能上取得了明显改善.     

Access课程网络题库的构建

本文以Access课程为例,探讨如何构建网络题库,研究Access课程网络题库的构建方法。实际应用效果表明,所构建的题库难度系数合理,考试结果的信度和效度较高,能够全面、客观、公正地评价学生的学习情况。     

Roles of salience and strategy in conjunction search.

In some cases, the search for a conjunction target proceeds through the smaller group of elements in a display, whereas in others, search is limited to those elements that share a particular feature with the target. In 6 experiments, participants searched for a conjunction target among displays consisting of various proportions of 2 distractor types. Smaller-group search was more prevalent than target-feature search with denser displays and with features that were highly discriminable. Explicit instructions to limit search to a specific feature affected performance only when the discriminability of the guiding feature was much greater than the other target feature. Together, these experiments show that bottom-up factors have more influence in guiding conjunction searches than previously thought. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于Gabor滤波器组的实时疵点图像分割

使用Gabor滤波器组进行布匹在线疵点检测与疵点图像分割。通过定义一个分辨力函数和一些合成的疵点图像,对已有的Gabor滤波器组的参数选择方式做出评价,提出了在实时应用场合有效地确定Gabor滤波器组参数的方法。分析指出：Gabor滤波器的实部输出是主要因素;滤波器的方位角仅选取疵点出现得最多的水平和垂直方向,而径向中心频率的选取依赖于纹理本身的固有频率;滤波器的长度也应与纹理的固有周期一致。尽管Gabor滤波器的个数减少到4个以满足实时性要求,但结果表明,滤波器组仍能很好地检测和分割出大多数疵点。     

基于压缩感知的SAR图像目标识别

提出一种基于压缩感知的合成孔径雷达图像目标识别方法,将目标识别问题转化为稀疏表示的近似求解问题。该方法利用测试样本在全体训练样本基下的稀疏性,实现样本间的近似稀疏表示。通过考察稀疏系数主要集中于样本真实类别之上的分布特性,研究了稀疏系数本身对目标类别具有的可区分能力,最后基于稀疏系数的分布特性设计分类算法完成目标识别。基于MSTAR数据中三类目标的实验证明,与目前已有的几种典型方法相比,该方法可以取得更高的识别率,是一种有效的合成孔径雷达图像目标识别方法。     

Local Proactive Interference in Delayed Matching to Sample: The Role of Reinforcement.

Discriminability in delayed matching to sample was lower when the samples on consecutive trials differed compared with when samples on consecutive trials were the same. This local proactive interference occurred when correct choices on the previous trial were reinforced but not when correct choices on the previous trial were not reinforced. When the choice on the previous trial was incorrect, discriminability was higher on different consecutive trials than on same trials. These effects were amplified by varying the ratio of reinforcers for correct choices, as predicted by a model that attributes local proactive interference to an interaction between control by the sample on the current trial and the influence of reinforcers for correct choices on previous trials. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Rational Design of All Resistive Multifunctional Sensors with Stimulus Discriminability

A rational approach is proposed to design soft multifunctional sensors capable of detection and discrimination of different physical stimuli. Herein, a flexible multifunctional sensor concurrently detecting and distinguishing minute temperature and pressure stimuli in real time is developed using electrospun carbon nanofiber (CNF) films as the sole sensing material and electrical resistance as the only output signal. The stimuli sensitivity and discriminability are coordinated by tailoring the atomic- and device-level structures of CNF films to deliver outstanding pressure and temperature sensitivities of ? 0.96 kPa^?1 and ? 2.44%  ° C^?1, respectively, enabling mutually exclusive sensing performance without signal cross-interference. The CNF multifunctional sensor is considered the first of its kind to accomplish the stimulus discriminability using only the electrical resistance as the output signal, which is most convenient to monitor and process for device applications. As such, it has distinct advantages over other reported sensors in its simple, cost-effective fabrication and readout system. It also possesses other invaluable traits, including good bending stability, fast response time, and long-term durability. Importantly, the ability to simultaneously detect and decouple temperature and pressure stimuli is demonstrated through novel applications as a skin-mountable device and a flexible game controller.     

Sequential Lineups: Shift in Criterion or Decision Strategy?

R. C. L. Lindsay and G. L. Wells (1985) argued that a sequential lineup enhanced discriminability because it elicited use of an absolute decision strategy. E. B. Ebbesen and H. D. Flowe (2002) argued that a sequential lineup led witnesses to adopt a more conservative response criterion, thereby affecting bias, not discriminability. Height was encoded as absolute (e.g., 6 ft [1.83 m] tall) or relative (e.g., taller than). If a sequential lineup elicited an absolute decision strategy, the principle of transfer-appropriate processing predicted that performance should be best when height was encoded absolutely. Conversely, if a simultaneous lineup elicited a relative decision strategy, performance should be best when height was encoded relatively. The predicted interaction was observed, providing direct evidence for the decision strategies explanation of what happens when witnesses view a sequential lineup. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparative judgment of numerosity and numerical magnitude: Attention preempts automaticity.

It is commonly believed that humans are unable to ignore the meanings of numerical symbols, even when these meanings are irrelevant to the task at hand. In 5 experiments, the authors tested the notion of automatic activation of numerical magnitude by asking participants to compare, while timed, pairs of numerical arrays on either numerosity or numerical value. Garner and Stroop effects were used to gauge the degree of interactive processing. The results showed that both effects were sensitive to the discriminability of values along the constituent dimensions, to the number of stimulus values used, and to practice and motivation. Notably, Stroop and Garner effects were eliminated under several conditions. These findings are incompatible with claims of obligatory activation of meaning in numerical processing, and they cast doubt on theories positing automatic processing of semantic information for alphanumerical symbols. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

数字图像伪彩色增强方法在岩土CT图像分析中的应用

直观岩土CT图像分析是最基本的CT分析方法，而高分辨率的岩土CT图像是这一分析方法的关键。为了提高岩土CT图像的分辨率，根据人眼的视觉特点，结合计算机数字图像颜色模式和图像格式，采用灰度级．彩色变换方法，对灰度CT图像进行伪彩色增强，显著地提高了CT图像的分辨率。