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921.
命题逻辑的一般弱框架择类语义是相干邻域语义的变形,其特点是:采用择类运算来刻画逻辑常项;语义运算与逻辑联结词之间有清晰的对应关系,可以从整体上处理一类逻辑,具有普适性。本文将这种语义用于一类B、C、K、W命题逻辑,包括相干逻辑R及其线性片段、直觉主义逻辑及其BCK片段等,并借助典范框架和典范赋值,证明了这些逻辑系统的可靠性和完全性。  相似文献   
922.
Prediction of complex behavioural tasks via relatively simple modelling techniques, such as logistic regression and discriminant analysis, often has limited success. We hypothesized that to more accurately model complex behaviour, more complex models, such as kernel-based methods, would be needed. To test this hypothesis, we assessed the value of six modelling approaches for predicting driving ability based on performance on computerized sensory-motor and cognitive tests (SMCTests?) in 501 people with brain disorders. The models included three models previously used to predict driving ability (discriminant analysis, DA; binary logistic regression, BLR; and nonlinear causal resource analysis, NCRA) and three kernel methods (support vector machine, SVM; product kernel density, PK; and kernel product density, KP). At the classification level, two kernel methods were substantially more accurate at classifying on-road pass or fail (SVM 99.6%, PK 99.8%) than the other models (DA 76%, BLR 78%, NCRA 74%, KP 81%). However, accuracy decreased substantially for all of the kernel models when cross-validation techniques were used to estimate prediction of on-road pass or fail in an independent referral group (SVM 73-76%, PK 72-73%, KP 71-72%) but decreased only slightly for DA (74-75%) and BLR (75-76%). Cross-validation of NCRA was not possible. In conclusion, while kernel-based models are successful at modelling complex data at a classification level, this is likely to be due to overfitting of the data, which does not lead to an improvement in accuracy in independent data over and above the accuracy of other less complex modelling techniques.  相似文献   
923.
目的采用学业自我效能感问卷、社会比较量表和成就目标定向量表,选取湘潭地区中学生,共计403名有效被试为对象进行研究,探讨中学生自我效能感、社会比较与成就目标的关系。结果发现,不同性别、年级中学生在成就目标、自我效能感和社会比较上的存在显著性差异;中学生自我效能感、成就目标和社会比较有显著相关;自我效能感与社会比较对成就目标有显著预测作用。  相似文献   
924.
目的:检验同伴教育干预实验是否能改变初中生的吸烟态度。方法:通过KAP问卷对实验组和对照组吸烟初中生收集量化数据,评价干预效果。结果:⑴同质同伴教育者在吸烟知识、态度和行为上有明显变化(后测结果显示三组被试在知识、态度和行为上的Z值分别为:9.036、8.278、7.206,P<0.05);⑵实验组比对照组在吸烟知识、态度和行为上有显著提高(同质组与比照组在知识、态度和行为上的Z值分别为:-2.400、-2.206、-2.123,P<0.05;异质组与比照组在知识、态度和行为上的Z值分别为:-2.400、-2.300、-2.430,P<0.05);⑶同质与异质实验组在吸烟知识、态度和行为上有显著提高(同质组前后测在知识、态度和行为上的Z值分别为:-2.919、-2.371、-2.437,P<0.05;异质组前后测在知识、态度和行为上的Z值分别为:2.890、-2.091、-2.419,P<0.05);[4]同质与异质同伴组的比较没有差异。结论:同伴教育干预方法可以在一定程度上改变初中生的吸烟态度,同质团体与异质团体在同伴教育干预中不存在差异。  相似文献   
925.
目的:探究贵州少数民族地区隔代教养对儿童人际和谐的关系。方法:采用祖父母隔代教养问卷和自编的少数民族地区儿童人际和谐问卷对贵州省都匀市6~14岁的儿童进行调查,并使用Spss15.0和Amos7.0对调查数据进行统计分析。结果:发现女生在家人和谐与传统型教养方式上得分显著高于男生,在族际和谐上与父母同住的儿童要显著高于与祖父母同住以及与父母、祖父母同住的儿童;各种隔代教养类型与儿童人际和谐均有显著的相关关系。结论:贵州少数民族地区隔代教养对儿童人际和谐具有显著的正向影响作用。  相似文献   
926.
本研究采用SCL-90、EPQ等量表,对苏中地区小学教师的人格特征与心理健康问题的关系进行了研究。研究结果表明:(1)苏中地区小学教师的人格特征与其心理健康状况显著相关。(2)苏中地区小学教师人格特征的N分、P分和E分因子进入心理健康因子的回归方程,是心理健康水平的关键性影响因素。(3)N分、P分和E分因子对心理健康的解释率为28.6%。  相似文献   
927.
Previous research has established that holding a stimulus in working memory (WM) facilitates the deployment of visual attention to that stimulus relative to other stimuli. The present study examined whether maintaining a specific task in WM would also bias the allocation of attention to the stimuli associated with that task. Participants performed a speeded letter search task while simultaneously keeping in WM one of two task cues shown at the beginning of each trial. The results showed that task-based WM guidance of attention was modulated by response latencies. Whereas the participants with fast reaction times showed little influence of WM contents, the participants with slow reaction times took longer to respond when the letter target appeared in a distractor stimulus consistent with the task cue held in mind. A subsequent Stroop experiment found a larger Stroop interference effect from the participants in the slow group compared with those in the fast group, suggesting that the differential WM effect between the two groups may be associated with an individual's ability to inhibit task-irrelevant information. Taken together, these results expanded the realm of previous research and provided further evidence for a close link between attention and WM.  相似文献   
928.
What is the best account to explain the object-based attentional benefit—that is, the spread of attention within an attended object or prioritization of search across possible target locations within an attended object? Using a task in which the location of the target was known with certainty, in the present study we systematically manipulated the type (letters or bites) and the presentation time (long or short) of the target and flankers in order to test the effects of target–object integration and target presentation time on object-based attention. The results showed that an object-based effect could appear when the target was a bite, no matter whether the target presentation time was long or short; but when the target was a letter, an object-based effect was only observed when the target presentation time was short enough. These findings provide additional evidence supporting the argument of attentional spreading in object-based attention. However, this spreading is moderated jointly by target–object integration and the target presentation time.  相似文献   
929.
The attentional processes for tracking moving objects may be largely hemisphere-specific. Indeed, in our first two experiments the maximum object speed (speed limit) for tracking targets in one visual hemifield (left or right) was not significantly affected by a requirement to track additional targets in the other hemifield. When the additional targets instead occupied the same hemifield as the original targets, the speed limit was reduced. At slow target speeds, however, adding a second target to the same hemifield had little effect. At high target speeds, the cost of adding a same-hemifield second target was approximately as large as would occur if observers could only track one of the targets. This shows that performance with a fast-moving target is very sensitive to the amount of resource allocated. In a third experiment, we investigated whether the resources for tracking can be distributed unequally between two targets. The speed limit for a given target was higher if the second target was slow rather than fast, suggesting that more resource was allocated to the faster of the two targets. This finding was statistically significant only for targets presented in the same hemifield, consistent with the theory of independent resources in the two hemifields. Some limited evidence was also found for resource sharing across hemifields, suggesting that attentional tracking resources may not be entirely hemifield-specific. Together, these experiments indicate that the largely hemisphere-specific tracking resource can be differentially allocated to faster targets.  相似文献   
930.
Spatial ventriloquism refers to the phenomenon that a visual stimulus such as a flash can attract the perceived location of a spatially discordant but temporally synchronous sound. An analogous example of mutual attraction between audition and vision has been found in the temporal domain, where temporal aspects of a visual event, such as its onset, frequency, or duration, can be biased by a slightly asynchronous sound. In this review, we examine various manifestations of spatial and temporal attraction between the senses (both direct effects and aftereffects), and we discuss important constraints on the occurrence of these effects. Factors that potentially modulate ventriloquism—such as attention, synesthetic correspondence, and other cognitive factors—are described. We trace theories and models of spatial and temporal ventriloquism, from the traditional unity assumption and modality appropriateness hypothesis to more recent Bayesian and neural network approaches. Finally, we summarize recent evidence probing the underlying neural mechanisms of spatial and temporal ventriloquism.  相似文献   
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