遗址展示中的三维数据采集需求与技术分析

本文旨在探讨如何从遗址价值研究和公众信息需求的角度分析遗址数据采集需求:同时结合实践经验对遗址数据采集工作中数据的标准化、精度要求以及适宜技术等几方面提出建议。     

基于主曲线的书法字动态重现算法

如何高效逼真地动态重现书法作品的创作过程日益成为亟需解决的问题,因此文中提出基于主曲线的书法字动态重现方法,解决当前细化算法在提取骨架时存在的无效分支较多、不能保证笔画的连续性和准确性的问题.结合书法字自身结构对主曲线算法进行改进和优化.对书法图像进行骨架提取、骨架追踪、笔顺获取等处理,结合骨架信息和二值图像实现笔画宽度复原,针对笔画宽度存在的“肿瘤”问题,提出“角点剔除法”进行修正,结合HTML5的Canvas绘图技术进行书法字动态书写过程.在模拟数据集上的实验表明,文中算法的书法动态重现取得较好效果.     

A quantitative analysis of pattern production and its relationship to expert performance

Abstract. The modelling and measurement of expertise is a relatively new research area in artificial intelligence and cognitive science. Many domains do not have a formal method for evaluating expertise. When formal methods exist, they are frequently inefficient. Using an extension to the IAM program, a pattern recognition and acquisition method for evaluating the level of expertise for the domain of chess is developed. Chess players, as well as experts in other domains, use cognitive chunks of perceptual patterns to gain a cognitive economy that enables them to evaluate complex domain situations faster and more accurately than novices. The IAM program acquires a representative collection of the perceptual patterns demonstrated by a domain expert and uses those patterns to analyse skill level. A longitudinal study of a developing player and a comparison of the developing player to an established expert demonstrates the utility of the developed method for evaluating expertise.     

Knowledge-based temporal interpolation

Temporal interpolation is the task of bridging gaps between time-oriented concepts in a context-sensitive manner. It is a subtask important for solving the temporal-abstraction task-abstraction of interval-based, higher-level concepts from time-stamped data. We present a knowledge-based approach to the temporal-interpolation task and discuss in detail the precise knowledge required by that approach, its theoretical foundations, and the implications of the approach. The temporal-interpolation computational mechanism we discuss relies, among other knowledge types, on a temporal-persistence model. The temporal-persistence model employs local temporal-persistence functions that are temporally bidirectional (i.e. extend a belief measure in a predicate both into the future and into the past) and global, maximal-gap temporal-persistence functions that bridge gaps between interval-based predicates. We investigate the quantitative and qualitative properties implied by both types of persistence functions. We have implemented our approach in the RÉSUMÉ program and evaluated it in several different medical and engineering domains. We discuss the implications of our conceptual and computational methodology for acquisition, maintenance, reuse, and sharing of temporal-abstraction knowledge.     

Analyzing existing customers’ websites to improve the customer acquisition process as well as the profitability prediction in B-to-B marketing

We investigate the issue of predicting new customers as profitable based on information about existing customers in a business-to-business environment. In particular, we show how latent semantic concepts from textual information of existing customers’ websites can be used to uncover characteristics of websites of companies that will turn into profitable customers. Hence, the use of predictive analytics will help to identify new potential acquisition targets. Additionally, we show that a regression model based on these concepts is successful in the profitability prediction of new customers. In a case study, the acquisition process of a mail-order company is supported by creating a prioritized list of new customers generated by this approach. It is shown that the density of profitable customers in this list outperforms the density of profitable customers in traditional generated address lists (e.g. from list brokers). From a managerial point of view, this approach supports the identification of new business customers and helps to estimate the future profitability of these customers in a company. Consequently, the customer acquisition process can be targeted more effectively and efficiently. This leads to a competitive advantage for B2B companies and improves the acquisition process that is time- and cost-consuming with traditionally low conversion rates.     

基于PMF-FFT的伪码捕获算法分析

建立了PMF-FFT算法的数学模型,分析了相关器个数、相关积累长度和FFT点数对积累损失、扇贝损失和频率分辨率的影响。在此基础上,结合算法的效率和运算量,给出了PMF-FFT算法参数选择的原则和依据。     

基于虚拟仪器的微震实时监测系统

煤矿中发生的岩爆、煤和瓦斯突出等地质灾害与岩体中的微震现象有着必然的联系,通过监测地下微震信号可以确定地下岩石破裂的范围和程度,为矿山的地下安全监测提供有力的证据。以往基于DSP或其他单片机的微震系统,其资源的有限性很难达到理想的采集效果,并且难以完成先进算法的实现;而本系统实现了对多路微震信号采集及先进的小波变换处理算法,充分发挥了虚拟仪器的优势。该系统的监测结果与实际矿震十分吻合,得到的定位结果小于规定的误差上限,很好地完成了对微震的实时监测及分析。     

GPS软件接收机中微弱信号捕获算法研究

信号捕获的目的是确定接收机当前所在位置的可见卫星号,进而计算可见卫星的载波频率和伪随机码相位信息.目前随着GPS接收机应用的日益广泛,如何在弱信号环境下实现定位的问题日益突出.普通的GPS接收机不能捕获和跟踪到导航卫星信号,只能设法提高GPS接收机的灵敏度来实现导航和定位.为了解决微弱信号情况下的GPS信号捕获问题,在...     

一种PN码快速捕获的方法

该文研究低信噪比情况下DS/SS系统中的序列捕获问题,提出来一种快速捕获的方法。该方法是在普通的非相干带通相关检测器基础上,增加了一个重复累加装置,相关峰值周期后,若未捕获信号,重新相关捕获,且相关值与上次相关值累加。研究表明,此方法可以提高信噪比,因此减少了捕获时间.在给定的仿真条件下,运行了仿真程序,得到了预期的结果。     

SEAP的电流信号采集系统的设计及验证

短电弧加工(SEAP)是解决特硬、超强、高韧性等难加工材料的表层去除加工难题的有效手段。介绍了短电弧机床电流信号采集系统的结构组成和工作原理,对该系统进行了SEAP电流信号的采集以及电流波形变化规律的初步分析。另外,还介绍了该系统对采集的信号进行滤波处理的两种方法:数字滤波器滤波及小波变换滤波。