纸上静态签名笔迹动态特征的提取和分析

目的建立一种新型的定量化签名笔迹鉴别技术。方法建立签名笔迹样本库，导入计算机后，提取签名笔迹的宽度，灰度和弧度等动态特征数据，进行时间归整后，比较签名动态特征之间的相关系数及其规律。结果同一人签名的动态特征之间相关系数高，而与代签签名、临摹签名和套摹签名均有显著差异。结论本研究开发和建立了一整套检测、提取和分析纸上签名笔迹动态特征的工具和方法，该方法能有效鉴别本人签名和非本人签名。     

浅析摹仿签名笔迹鉴定

摹仿签名笔迹检验是笔迹检验的难点,认定签名摹仿人更是难中之难;笔者通过正确确定签名笔迹的真伪,从签名笔迹的概貌特征和细节特征之中运用辩证的观点正确认定摹仿人。     

浅谈对签名笔迹的检验

1 签名笔迹的特点 签名笔迹与其它笔迹相比较,有其独自的特点:1.签名笔迹的案由都是涉及到经济问题;2.签名笔迹字数少(两、三个字);3.签名笔迹的相同字、同名部首及同名笔画少;4.签名笔迹重复出现的笔迹特征少;5.签名笔迹可比性强的特征少。 2 对签名笔迹检验的方法 对签名笔迹检验的方法,是遵循同一认定的基本原理,对送检文字材料的笔迹特征同嫌疑人     

签名笔迹动态特征的理论研究

本文以签名笔迹为研究对象,提取书写过程中的动态特征,在此基础上,对签名笔迹动态特征的概念和属性进行了深入的探讨,构建了一套较为完整的签名笔迹动态特征的理论系统。     

浅谈签名笔迹的独特特征

签名,是指享有某些权利或应尽有关义务的个人在有关文件上签署自己的姓名所形成的文字。签名和印文一起构成了文件及其所载内容的真实性和有效性的凭证。本文拟就签名笔迹独特特征的形成、表现形式以及对签名笔迹独特特征的寻找与运用做一些初步探讨。一、签名笔迹独特特征的形成本文所说的签名笔迹独特特征,是指非摹仿性的本质性的自然形成的独特的书写习惯的反映。签名笔迹的独特特征形成的因素很多,概括起来有以下几点:(一)心理因素;(二)生理因素;(三)审美观念和书写艺术素质不同的影响;(四)执笔方法不同的影响;(五)书写工具不同的影响。…     

再看摹仿签名笔迹鉴定

由于签名笔迹字数少、可摹仿性强的特点,长期以来,摹仿签名笔迹鉴定始终是笔迹鉴定的难点。笔者从不同类型的摹仿方法出发,讨论不同方法下摹仿签名笔迹的特点,总结其特征规律。同时要重视笔迹鉴定过程中了解相关案情,为识别是否存在摹仿现象提供线索。在此基础之上,对比摹仿签名笔迹特征的变化规律,并从摹仿签名笔迹特征反映构成方面系统性地进行鉴定,鉴别是否存在摹仿签名的情况。通过撰写此文,以期对摹仿签名笔迹鉴定实务具有借鉴意义。     

签名笔迹及其检验研究

签名笔迹检验一直是文件检验中的难点,案件涉及比例居高,并呈上升之势。此类字迹,字符特征少,书写习惯反应不充分,检验难度大。因此,通过对签名笔迹主要类型、特点、检验方法等相关问题的探究,来增强对签名笔迹的认识以及提高签名笔迹检验的实践能力,意义重大。     

从摹彷签名笔迹造特征探究检验及鉴定

对摹仿签名笔迹的检验是文检鉴定工作中常见的工作之一,不少文检工作者对此均有各自的见解.本文结合十余年文检工作经验和体会,从摹仿签名笔迹的主、客观特征、识别要点、检验原则等几个方面对摹仿签名笔迹进行识别和检验,提出了从摹仿签名笔迹受主、客观因素影响而形成的主、客观特征出发,运用综合评断原则对其进行检验及鉴定的观点.     

中文签名笔迹动态特征研究

从物理学角度看,笔迹是书写工具在力的作用下在载体上形成的运动轨迹。作用力和速度的大小和变化构成了书写运动的动态特征。本文以签名笔迹为对象,研究签名笔迹的动态特征及其属性。实验结果表明：动态特征能够作为认定书写人,鉴别摹仿签名的重要依据。     

中文签名笔迹动态特征研究

从物理学角度看,笔迹是书写工具在力的作用下在载体上形成的运动轨迹.作用力和速度的大小和变化构成了书写运动的动态特征.本文以签名笔迹为对象,研究签名笔迹的动态特征及其属性.实验结果表明动态特征能够作为认定书写人,鉴别摹仿签名的重要依据.     

The potential of collaborative learning as a tool for forensic students: Application to signature examination

Transferring theoretical knowledge to practical skills remains a big challenge in forensic science, especially in questioned documents. The examination of handwriting and signatures requires years of practice to develop the necessary skills. While students (and to some extent the general population) often have the impression that it is easy to differentiate handwriting from different persons, in practice, particularly when dealing with simulated signatures, there is a high risk of reaching a wrong conclusion when questioned document experts do not use a systematic approach and/or are not sufficiently experienced (see for example the famous French Dreyfus case). Thus, a novel teaching approach, based on collaborative learning, has been introduced in a theoretical handwriting class to improve the students’ theoretical knowledge, and additionally make them aware of the limitations of their practical skills and give them tools to improve them in their future practice. Through five activities, the students took the roles of victims, forgers, teachers and experts and created their own learning materials (i.e. signatures and mock casework). During those interactive activities, they learned to describe their signature’s characteristics, intra-variability and complexity, and thus evaluate their own signature’s vulnerability (as potential victims). They learned techniques to simulate signatures and detect the resulting forgeries’ characteristics (in the role of forgers). In the role of teachers, they prepared mock casework scenarios and gave feedback to their colleague’s examination of the produced material. As experts, they carried out signature examination as they would in a proficiency test and were exposed to the difficulties an actual expert may encounter in practice. The evaluation of this novel teaching scenario was very positive, as students learned more extensively the possibilities and limitations of signature comparison. They were more active and motivated in their learning experiences. The teaching team also had an improved experience. Some students complained of an increased workload and imprecise instructions. Improvements were tested and are discussed in this paper.     

Dynamic Characteristics of Signatures: Effects of Writer Style on Genuine and Simulated Signatures

The aims of this study were to determine if computer‐measured dynamic features (duration, size, velocity, jerk, and pen pressure) differ between genuine and simulated signatures. Sixty subjects (3 equal groups of 3 signature styles) each provided 10 naturally written (genuine) signatures. Each of these subjects then provided 15 simulations of each of three model signatures. The genuine (N = 600) and simulated (N = 2700) signatures were collected using a digitizing tablet. MovAlyzeR^® software was used to estimate kinematic parameters for each pen stroke. Stroke duration, velocity, and pen pressure were found to discriminate between genuine and simulated signatures regardless of the simulator's own style of signature or the style of signature being simulated. However, there was a significant interaction between style and condition for size and jerk (a measure of smoothness). The results of this study, based on quantitative analysis and dynamic handwriting features, indicate that the style of the simulator's own signature and the style of signature being simulated can impact the characteristics of handwriting movements for simulations. Writer style characteristics might therefore need to be taken into consideration as potentially significant when evaluating signature features with a view to forming opinions regarding authenticity.     

Investigating forensic document examiners’ skill relating to opinions on photocopied signatures

Many forensic document examiners are hesitant to express authorship opinions on photocopied handwriting as the photocopying process results in less feature information than original writing. This study aimed to test the accuracy of 15 examiners' opinions regarding whether photocopied questioned signatures were genuine or simulated. Each examiner received the same set of original signature exemplars, from one individual, and a set of eighty questioned photocopied signatures comprising of genuine and simulated signatures. The overall misleading (error) rate for the grouped examiners' opinions was 0.9% providing strong evidence that examiners can make accurate observations regarding the authorship of non-original handwriting.     

Distinguishing Characteristics of Robotic Writing

Advances in robotic handwriting technology create new challenges for forensic document examiners. In the past, devices such as the autopen were used to replicate signatures of government officials and corporate companies. In today's technology, companies such as Bond utilize robots to create written documents, which mimic natural patterns of handwriting. They generate customizable written samples by simulating pen movements and letter formations. Four forensic document examiners were given various reproduced questioned documents and utilized a modified ACE‐V (analysis, comparison, evaluation, verification) methodology to determine their genuineness. Examiners were able to make a distinction between the human writing samples and the skilled robotic equivalents. Several distinct features that are not seen in natural handwriting, such as even pen pressure and the superimposition of letterforms were observed in the robotic samples. Careful examination of identifying features of the Bond produced documents resulted in an opinion of nongenuineness.     

老年人笔迹变化的形成原因和特点

世界人口老龄化发展的历史表明,人口老龄化对人类社会生活的各个方面都会产生重大的影响。因此,研究老年人笔迹特点及其变化规律对于老年人笔迹鉴定具有理论指导意义和实用价值。根据老年人笔迹变化的形成原因和对老年人笔迹的实验统计分析,包括横向分析、纵向分析、病理性变化的分析,得出了老年人笔迹的特点。     

一起練习记忆摹仿签名笔迹的鉴定与启示

本文通过对一起检验鉴定案例的分析,提出练习记忆摹仿的概念,并对该类案件的检验鉴定,总结出十点启示。     

从哲学、书法鉴赏角度把握笔迹鉴定中的“神韵”

笔迹鉴定实践中往往过分关注笔迹的微观细节特征而忽略从整体角度把握笔迹。“神韵”是笔迹整体所具有的特征，它要求我们鉴定笔迹时不但从微观入手而且更要从宏观上把握。     

Dating a signature

With the use of actual case material it will be illustrated that signatures can be placed in an approximate time frame as to the date they were executed. By both historical means as well as by the individual changes in handwriting characteristics, the arrangement of signatures in order of occurrence will be demonstrated.     

Are expert penmen better than lay people at producing simulations of a model signature?

Although forensic signature examination is considered to be an identification science, it is a theoretical possibility that an individual may learn to forge another person's signature that is free from indications of simulation behaviours. This proposition was tested in a signature blind trial that was administered to 42 forensic handwriting examiners (FHEs). Participants expressed opinions on the authorship of 100 questioned signatures. The questioned signatures comprised a mixture of genuine, disguised and simulated signatures. Calligraphers formed part of the population of individuals who provided simulated signatures for the trial. A total of 3100 opinions were expressed of which 1254 were correct, 224 misleading and 1622 were inconclusive. Of the opinions expressed regarding the simulated signatures, the misleading score for the calligraphers' forgeries were approximately four times that of the lay persons' forgeries. These results provide strong evidence in support of the proposition that calligraphers are more skilled at simulating signatures than are lay people and can produce forgeries that some FHEs have difficulty detecting.     

浅谈笔迹线条主动触觉在笔迹鉴定中的运用

笔迹是书写运动的轨迹,在观察静态特征的同时运用其动态特征,无疑可以提高笔迹鉴定的水平。但如何获取字迹的书写压力、书写速度和加速度等动态特征,目前还是个难题。笔迹心理学中笔迹线条主动触觉的分析是将笔迹书写时的压力与速度贯穿于字迹观察分析的始终,将其运用于笔迹鉴定,可在传统的笔迹鉴定二维平面字迹特征的视觉观察分析模式基础上,将视觉观察与触觉体验相结合,形成字迹形态二维平面特征与书写时笔向下的力度,和沿笔画书写的速度相结合的四维特征观察分析模式。