Visual Models in Analogical Problem Solving

Visual analogy is believed to be important in human problem solving. Yet, there are few computational models of visual analogy. In this paper, we present a preliminary computational model of visual analogy in problem solving. The model is instantiated in a computer program, called Galatea, which uses a language for representing and transferring visual information called Privlan. We describe how the computational model can account for a small slice of a cognitive-historical analysis of Maxwell’s reasoning about electromagnetism.     

Distribution of sister chromatid exchanges in different types of chromatin in the X chromosome ofMicrotus cabrerae

We used the X chromosomes ofMicrotus cabrerae as a model to analyze the distribution of sister chromatid exchanges (SCEs) on different types of chromatin, because of the marked heterogeneity of the heterochromatin in the entire short arm and a portion of the long arm of this chromosome. Computer-simulated distributions, according to an algorithm that makes it possible to modify the distribution on the basis of any possible hypothesis, were compared with real distributions by log-linear models. We found that the frequency of SCEs in different types of heterochromatin was higher than that expected for a random distribution, and located an SCE hot-spot at the junction between euchromatin and heterochromatin. The possible relationship between the distribution of SCEs and base composition or chromatin accessibility are discussed.     

激光散斑验光仪的改进研究

本文介绍了激光散斑验光的原理,提出了散斑验光仪的改进方案,通过实验研究,解决了散斑验光仪的技术问题。