古代汉字展示的视觉序列在日常生活中的发展

中国古代汉字的视觉序列是单行的从上到下、横列的从右到左。战国以后,文字的视觉序列便由此随着文字一起为更多的人所的认识及使用。围绕人们生活周围的视觉序列更是丰富多彩,如:招幌、商业印刷品、对联及园林匾额和楹联等等。     

A functional equations approach to nonlinear discrete-time feedback stabilization through pole-placement

The present work proposes a new approach to the nonlinear discrete-time feedback stabilization problem with pole-placement. The problem's formulation is realized through a system of nonlinear functional equations and a rather general set of necessary and sufficient conditions for solvability is derived. Using tools from functional equations theory, one can prove that the solution to the above system of nonlinear functional equations is locally analytic, and an easily programmable series solution method can be developed. Under a simultaneous implementation of a nonlinear coordinate transformation and a nonlinear discrete-time state feedback control law that are both computed through the solution of the system of nonlinear functional equations, the feedback stabilization with pole-placement design objective can be attained under rather general conditions. The key idea of the proposed single-step design approach is to bypass the intermediate step of transforming the original system into a linear controllable one with an external reference input associated with the classical exact feedback linearization approach. However, since the proposed method does not involve an external reference input, it cannot meet other control objectives such as trajectory tracking and model matching.     

Functional linear regression after spline transformation

Functional linear regression has been widely used to model the relationship between a scalar response and functional predictors. If the original data do not satisfy the linear assumption, an intuitive solution is to perform some transformation such that transformed data will be linearly related. The problem of finding such transformations has been rather neglected in the development of functional data analysis tools. In this paper, we consider transformation on the response variable in functional linear regression and propose a nonparametric transformation model in which we use spline functions to construct the transformation function. The functional regression coefficients are then estimated by an innovative procedure called mixed data canonical correlation analysis (MDCCA). MDCCA is analogous to the canonical correlation analysis between two multivariate samples, but is between a multivariate sample and a set of functional data. Here, we apply the MDCCA to the projection of the transformation function on the B-spline space and the functional predictors. We then show that our estimates agree with the regularized functional least squares estimate for the transformation model subject to a scale multiplication. The dimension of the space of spline transformations can be determined by a model selection principle. Typically, a very small number of B-spline knots is needed. Real and simulation data examples are further presented to demonstrate the value of this approach.     

An investigation of stability limits while holding a load

The objective of this study was to investigate the effects of load height and foot placement on the functional base of support (FBOS) limits and the postures that participants used when they reached their FBOS limits. Twelve young male participants were tested while holding a 12-kg load at reach (above their heads), at shoulder and knuckle height, and unladen under both wide and narrow foot placements. The FBOS limits and the centre of pressure (COP) excursion length were calculated based on data from a force platform. Postural angles when participants reached their FBOS limits were calculated from records of a 2-D motion analysis system. The results showed that the load height had greater effect on the posterior FBOS limit. As the load height decreased, the COP excursion length decreased. Participants were prone to using a hip strategy to maintain postural balance when reaching their FBOS limits. Quantitative data of FBOS limits and postural control while participants hold a load at various heights when reaching their FBOS limits is of value for designing a safe materials handling workplace.     

The effects of age,viewing distance,display type,font type,colour contrast and number of syllables on the legibility of Korean characters

This study evaluated the effects of age (20s and 60s), viewing distance (50 cm, 200 cm), display type (paper, monitor), font type (Gothic, Ming), colour contrast (black letters on white background, white letters on black background) and number of syllables (one, two) on the legibility of Korean characters by using the four legibility measures (minimum letter size for 100% correctness, maximum letter size for 0% correctness, minimum letter size for the least discomfort and maximum letter size for the most discomfort). Ten subjects in each age group read the four letters presented on a slide (letter size varied from 80 pt to 2 pt). Subjects also subjectively rated the reading discomfort of the letters on a 4-point scale (1 = no discomfort, 4 = most discomfort). According to the ANOVA procedure, age, viewing distance and font type significantly affected the four dependent variables (p < 0.05), while the main effect of colour contrast was not statistically significant for any measures. Two-syllable letters had smaller letters than one-syllable letters in the two correctness measures. The younger group could see letter sizes two times smaller than the old group could and the viewing distance of 50 cm showed letters about three times smaller than those at a 200 cm viewing distance. The Gothic fonts were smaller than the Ming fonts. Monitors were smaller than paper for correctness and maximum letter size for the most discomfort. From a comparison of the results for correctness and discomfort, people generally preferred larger letter sizes to those that they could read. The findings of this study may provide basic information for setting a global standard of letter size or font type to improve the legibility of characters written in Korean.

Statement of Relevance: Results obtained in this study will provide basic information and guidelines for setting standards of letter size and font type to improve the legibility of characters written in Korean. Also, the results might offer useful information for people who are working on design of visual displays.     

Display text segmentation after learning best-fitted OCR binarization parameters

In this paper text segmentation in generic displays is proposed through learning the best binarization values for a commercial optical character recognition (OCR) system. The commercial OCR is briefly introduced as well as the parameters that affect the binarization for improving the classification scores. The purpose of this work is to provide the capability to automatically evaluate standard textual display information, so that tasks that involve visual user verification can be performed without human intervention. The problem to be solved is to recognize text characters that appear on the display, as well as the color of the characters’ foreground and background. The paper introduces how the thresholds are learnt through: (a) selecting lightness or hue component of a color input cell, (b) enhancing the bitmaps’ quality, and (c) calculating the segmentation threshold range for this cell. Then, starting from the threshold ranges learnt at each display cell, the best threshold for each cell is gotten. The input and output data sets for testing the algorithms proposed are described, as well as the analysis of the results obtained.     

CAPTCHA技术研究综述

全自动开放式人机区分图灵测试(completely automated public Turing test to tell computers and humans apart,CAPTCHA)又称为人机交互验证(human interactive proof,HIP),它能自动产生并评估一个测试,这个测试能被几乎所有人类用户通过,而现有的计算机程序不能通过.CAPTCHA提供了一种自动驱分人和机器的手段,已成为一种标准的网络安全技术成功应用于包括Google,Yahoo!以及微软在内的各大网站.CAPTCHA设计基于人工智能领域的开放性问题,按表现载体和内容不同分为文本、图像、声音3种类型,其中,基于字符识别的文本CAPTCHA已得到广泛使用;图像CAPTCHA利用计算机视觉中的难解问题,目前尚处于研究阶段;声音CAPTCHA针对视觉残障者,是对前两种视觉CAPTCHA的补充.介绍了CAPTCHA的发展和设计准则,详细阐述CAPTCHA设计和破解的研究工作及最新进展,给出典型实例,讨论其可用性和安全性,最后指出未来CAPTCHA技术的发展方向和亟待解决的问题.     

高师美术教育改革与师资人才培养

高师美术教育的培养目标是适应九年义务教育发展的需要，培养具有现代教育观念的高素质的中学美术教师。要在高师美术教育改革中进一步强调培养学生的综合素质,调整完善课程体系和教学内容，突出“师范性”特点。下大力气抓中青年教师的培养．提高高师美术专业整体水平。     

超高压并联电抗器的结构特点和运行情况综述

综述了国内外超高压并联电抗器的设计制造和运行情况；重点介绍了国内外不同厂家生产的电抗器的结构特点,以及针对并联电抗器的漏磁发热、振动噪音、损耗等问题所采取的特殊结构措施；分析了我国超高压电网中运行的并联电抗器存在的主要问题,提出了高压并联电抗器的运行监督维护建议。     

具有连续参数齐次随机场的线性预测(Ⅱ)

本文提出和研究具有连续参数齐次随机场在带状区域上的线性预测问题,求出了它的预测值与预测误差,同时也得到了具有一个连续参数的平稳随机过程的线性内插的对应结果。