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971.
Constrained canonical correlation 总被引:1,自引:0,他引:1
This paper explores some of the problems associated with traditional canonical correlation. A response surface methodology is developed to examine the stability of the derived linear functions, where one wishes to investigate how much the coefficients can change and still be in an -neighborhood of the globally optimum canonical correlation value. In addition, a discrete (or constrained) canonical correlation method is formulated where the derived coefficients of these linear functions are constrained to be in some small set, e.g., {1, 0, –1}, to aid in the interpretation of the results. An example concerning the psychographic responses of Wharton MBA students of the University of Pennsylvania regarding driving preferences and life-style considerations is provided.Wayne S. DeSarbo, Robert Jausman, Shen Lin, and Wesley Thompson are all Members of Technical Staff at Bell Laboratories. We wish to express our gratitude to the editor and reviewers of this paper for their insightful remarks. 相似文献
972.
本实验探讨了3—6岁学前儿童的视、触大小知觉的发展规律及视、触不同感觉道在大小知觉中的相互作用。结果表明:无论哪一个年龄组的儿童均以“视—视”条件的大小知觉结果最优,其次是“触—触”条件的结果,而“视—触”及“触—视”的结果均较差。本文结果否定了认为交叉感觉道(“视—触”、“触—视”)对大小知觉的辨别与单一感觉道(“视—视”,“触—触”)没有差异的看法。实验结果还表明了,学前儿童的视、触大小知觉有其发展变化的特点。单一感觉道(视—视”,“触—触”)的大小知觉的准确性随着年龄的增长而提高;交叉(不同)感觉道(“视—触”,“触—视”)的大小知觉的准确性在5岁阶段为高峰期,6岁后便开始有所下降。 相似文献
973.
974.
975.
使群体隔离大白鼠接受急性和慢性铃声刺激,以观察隔离对大白鼠听源性癫痫的发生和适应过程的影响,同时观察其与脑内单胺类神经介质含量变化的关系。 结果表明急性声音应激时群体隔离动物癫痫发生率高。在铃声应激后隔离鼠端脑内NE含量显著减少。在连续6天的慢性声音应激时隔离大白鼠的适应过程稍慢。在6天中发生癫痫和狂跑的总次数隔离鼠也明显高于群居鼠。在第六天测定时发现隔离鼠脑干内NE含量明显低于群居鼠。群居鼠端脑和脑干内5-HT含量及隔离鼠端脑内5-HT含量明显增高。第七天测定时群居鼠端脑内NE含量明显增高,隔离鼠端脑与脑干内5-HIAA含量明显增高。上述结果表明隔离动物对铃声刺激的应付能力减弱,适应过程减慢。这种现象可能与隔离动物脑内NE和5-HT的生物合成受限有关。 相似文献
976.
Huang W 《Memory & cognition》1999,27(6):1080-1086
This study investigated how reasoning about conventional time information varied as a function of conventional time systems by using the Chinese month and Jieqi systems. Twenty Chinese students were asked to answer month-related questions and another 20 were asked to answer Jieqi-related questions. Reaction time and accuracy were the dependent measures. A cross-boundary effect was observed in processing months, and distance and direction effects were obtained when participants judged the interval of Jieqi. These results suggested that arithmetic operations were used in Chinese reasoning about months and verbal-articulatory processes were used for the Jieqi. The effects of mode of language representation on cognition and the strategies for cross-linguistic study are discussed. 相似文献
977.
Ialongo NS Werthamer L Kellam SG Brown CH Wang S Lin Y 《American journal of community psychology》1999,27(5):599-641
We assessed the immediate effects of two universal, first-grade preventive interventions on the proximal targets of poor achievement, concentration problems, aggression, and shy behaviors, known early risk behaviors for later substance use/abuse, affective disorder, and conduct disorder. The classroom-centered (CC) intervention was designed to reduce these early risk behaviors by enhancing teachers' behavior management and instructional skills, whereas the family-school partnership (FSP) intervention was aimed at improving parent-teacher communication and parental teaching and child behavior management strategies. Over the course of first and second grades, the CC intervention yielded the greatest degree of impact on its proximal targets, whereas the FSP's impact was somewhat less. The effects were influenced by gender and by preintervention levels of risk. Analyses of implementation measures demonstrated that greater fidelity to the intervention protocols was associated with greater impact on behavior ratings and on achievement scores, thus providing some evidence of specificity in the effect of the interventions. 相似文献
978.
Development of Sustained Attention Assessed Using the Continuous Performance Test among Children 6–15 Years of Age 总被引:4,自引:0,他引:4
The Continuous Performance Test (CPT) is a widely used measure of sustained attention, which may rely on the efficiency of cognitive inhibition. We examined the relationships of age and sex with CPT performance among 341 randomly selected school children 6–15 years of age. Multiple regression analyses revealed that the hit rate, false alarm rate, and sensitivity of both the undegraded and the degraded CPT were associated with age by a quadratic relationship. The age–development curves for the hit rate and sensitivity were convex, whereas that for the false alarm rate was concave. Sex was associated with the hit rate and sensitivity on the degraded CPT only. Our findings are consistent with the hypothesis that sustained attention develops during the primary school ages. The data reported are essential for identifying children with conditions associated with sustained attention deficit, such as attention-deficit hyperactivity disorder, as well as those at an increased risk for developing schizophrenia. 相似文献
979.
对适应性细胞保护的辩证思考 总被引:1,自引:0,他引:1
林国华 《医学与哲学(人文社会医学版)》1999,20(6):27-28
细胞遭受非致命的损伤刺激后能对随后更大的损伤产生防御和保护作用,这种现象被称为适应性细胞保护。损伤和抗损伤是疾病发展过程中一对基本矛盾,机体细胞具有内源性抗损伤机制。采用非致命性损伤刺激作为预处理的手段,从而调动细胞的适应性保护能力,将给有关疾病的防治提供新的应用前景。预适应手段和细胞内源性抗损伤机制两者是外因和内因的辩证统一,存在因果关系的多样性。同时,适应性细胞保护也有其相对的一面,表现为种属相对性和保护能力的相对性。 相似文献
980.
内隐知识表征的性质与研究 总被引:2,自引:0,他引:2
内隐学习是当分认知和学习领域经内隐记忆之后又一重要的研究课题。其中,关于内隐学习所获知识的性质问题是最具争议的问题之一,本文介绍了在这个问题上的三种主要观点:抽象观、分布的例子基础观、片断观,并对各种观点的实验性证据进行了总结和分析。 相似文献