声纹鉴定中的音强特征研究

目的 确定声纹鉴定中的音强特征的应用价值.方法 将10名条件相近、普通话较标准的男性发音人的语音样本输入VS-99型语音工作站,分别对每个人所发的相同音节韵母的宽带声纹图谱进行分析比对.结果 不同人发出的相同音节,其音强分布一般不同,有时还会出现明显的差异,主要表现在韵母总体音强按频率分布状态、韵母总体音强按时间分布状...     

言语习惯特征在声纹鉴定中的作用

言语习惯特征是人们在学习言语过程中,受环境因素和个体因素影响,逐渐形成的一类语音声学特征,它包括:方言、口音、惯用语、俚语、赘语,有的人说普通话时夹杂的地方方言特征;以及言语的速率、清晰度、流畅度、语音喉化、气嗓音、言语缺欠等[1]。大量实验和研究表明,对个人语音特征的形成起决定作用的,是发声系统的解剖学形状和发音方法的动态个人特点。从生理、心理学机制来看,言语的形成包括言语神经机制、言语的脑机制、言语的感知、思维和反映模式,是一个复杂的心理生理过程。每个人从“咿呀学话”开始,经过千百次“听想说”的学习、校练…     

汉语普通话音高模式在话者鉴别中的应用

汉语普通话是声调语言,不同话者在基频水平和声调变化规律方面存在差异。本文利用常规软件分析不同话者的基频数据变化规律,经过归一化和多次曲线拟合后,形成具有明显形态特征的音高模式曲线。通过比对分析音高模式曲线的形态和模式参数差异,可以帮助实现话者鉴别的目的 。     

An unusual case of identification by DNA analysis of siblings

A badly decomposed body required identification by means of DNA analysis. A brother and sister of the deceased were available as reference subjects. Although investigation of Y-chromosomal markers established an exclusion condition, autosomal markers suggested a positive identification. In order to increase the reliability of the tests, X-chromosomal markers were also investigated. This analysis showed the body to have an XXY genotype (Klinefelter's syndrome). A number of hypotheses were assessed using biostatistical methods, ultimately resulting in a definite identification. The special aspect of Klinefelter's syndrome proved highly useful for biostatistical analysis.     

Three-dimensional surface topography acquisition and analysis for firearm identification

In the last decade, computer-based systems for the comparison of microscopic firearms evidence have been the subject of considerable research work because of their expected capability of supporting the firearms examiner through the automated analysis of large amounts of evidence. The Integrated Ballistics Identification System, which is based on a two-dimensional representation of the specimen surface, has been widely adopted in forensic laboratories worldwide. More recently, some attempts to develop systems based on three-dimensional (3D) representations of the specimen surface have been made, both in the literature and as industrial products, such as BulletTRAX-3D, but fundamental limitations in achieving fully automated identification remain. This work analyzes the advantages and disadvantages of a 3D-based approach by proposing an approach and a prototype system for firearms evidence comparison that is based on the acquisition and analysis of the 3D surface topography of specimens, with particular reference to cartridge cases. The concept of 3D virtual comparison microscope is introduced, whose purpose is not to provide fully automated identification, but to show how the availability of 3D shape information can provide a whole new set of verification means, some of them being described and discussed in this work, specifically, visual enhancement tools and quantitative measurement of shape properties, for supporting, not replacing, the firearm examiner in reaching the final decision.     

Long-term working memory in voice identification

Abstract

The present study investigated the role of long-term working memory in voice identification. For this purpose, a mock theft design was used and three groups: voice identification experts, totally blind people and a control group of sighted listeners without any special training or experience in voice identification, were compared for their voice identification efficiency.

Results revealed that the professional voice identification experts were more accurate than the other groups. Blind listeners were as effective as the sighted in voice identification. The results confirmed predictions which were based on the long-term working memory model. Implications of these results for the practice of voice identification are discussed.     

判别函数在同胞鉴定中的应用

目的探讨判别函数法在全同胞与半同胞鉴定中的应用价值。方法根据360对全同胞、90对半同胞及360对无关个体的15个STR基因座分型结果,计算全不同(X0)、半相同(X1)和完全相同(X2)的基因座数目,分别根据DFS1=3.898X0+3.973X1-19.481,DHS1=5.687X0+5.300X1-35.112及DR1=7.309X0+5.533X1-44.941的全同胞/半同胞/无关个体判别函数、DFS2=3.872X0+3.931X1-18.895及DR2=7.303X0+5.473X1-44.298全同胞/无关个体判别函数和DHS3=10.227X0+10.436X1-66.102及DR3=11.863X0+11.089X1-79.494半同胞/无关个体判别函数进行判别。结果判别准确率:①用全同胞/半同胞/无关个体判别函数,全同胞组为83.61%,半同胞组为81.11%,无关个体组为83.06%;②用全同胞/无关个体判别函数,全同胞组为96.39%,无关个体组为98.61%;③用半同胞/无关个体判别函数,半同胞组为88.89%,无关个体组为85.00%。结论本文3种判别函数可应用于同胞鉴定,尤其运用全同胞/无关个体判别函数判断同胞关系准确率高,有较高的应用价值。     

中国黄种人与白种人脑颅骨特征差异初探

目的建立利用脑颅骨特征推断黄种人和白种人种族的判别方程,并评价其法医学意义。方法收集141例成年人脑颅骨样本,其中黄种人60例,白种人81例。选取脑颅骨lO项特征指标,对125例样本进行测量,运用SPSS16．0软件对指标数据进行t检验和Fisher判别分析,建立判别方程。并使用16例样本对方程的判别正确率进行盲测。结果本文选择的10项脑颅骨特征指标变量均具有显著性种族差异（P〈0．05）;建立了5组单项指标和4组多项指标进行种族推断的判别方程,综合判别率为74．4％～94．4％;随机选取16例样本的盲测结果,正确率为81．3％-100％。结论脑颅骨具有种族差异性,本文建立的判别方程可在黄种人和白种人的种族推断中选用。     

51个常染色体STR基因座在ITO法判断全同胞中的应用

目的探讨ITO法和判别函数法在全同胞鉴定中的应用价值。方法根据342对全同胞和3 900对无关个体的19、21、39、51个常染色STR基因座的分型结果,采用ITO法计算全同胞关系指数(FSI)。用SPSS软件Fisher判别分析法,分别建立lg FSI全同胞-无关个体的判别函数。结果每组全同胞对和无关个体对的lg FSI符合正态分布,具有显著性差异。在19、21、39、51个STR基因座,全同胞组判别函数分别为L同胞=1.666 6×lg FSI-5.208 0,L同胞=1.643 9×lg FSI-5.512 0,L同胞=1.569 4×lg FSI-8.076 4,L同胞=1.480 7×lg FSI-9.860 9;无关个体组分别为L无关=-1.346 1×lg FSI-3.638 5,L无关=-1.330 9×lg FSI-3.851 7,L无关=-1.319 2×lg FSI-5.910 2,L无关=-1.273 8×lg FSI-7.477 6。平均错判率分别为:1.361 9%、1.228 5%、0.438 6%和0.146 2%。结论 ITO判别函数法在全同胞-无关个体鉴定中具有很高的应用价值,且检测基因座越多,系统效能越高,并能降低错判风险。     

废水样中总硝基化合物的定量分析

利用气相色谱/质谱联用法对废水样中的2、4-二硝基甲苯和TNT进行了定性和定量分析,测定了废水中总硝基化合物的浓度.     

吸毒案件中的尿吗啡检测

目的　研究吸毒人员停止使用毒品海洛因后 ,尿吗啡含量自然递减的一般规律。方法　对确证的 1 82名吸毒 (海洛因 )人员在停止使用毒品后连续 9天采集尿样 ,用放射免疫分析法检测尿吗啡含量。结果　 1 82名吸毒 (海洛因 )人员在停止吸毒后第 8天 ,尿吗啡平均含量降至 30ng/ml。 结论　在办案中 ,吸毒 (海洛因 )人员的尿样检测 ,建议最好在末次使用海洛因 8天之内     

正畸治疗前后腭皱的法医同一认定研究

目的利用腭皱模型分析法评价腭皱形态的个体独特性及正畸治疗前后腭皱形态的稳定性,探索腭皱形态在法医齿科学个体识别应用中的可靠性。方法分别收集70例正畸治疗前、后的上颌模型。通过模型测量分析对腭皱形态及个体识别进行检测,包括数量、方向、形状及长度的变化和近、远中侧端点分别在近远中向及前后方向上的位移。同时对正畸治疗前、后及正畸治疗后与其复制后腭皱模型进行配对检测,计算其平均正确配对率(%)。结果 (1)正畸治疗后腭皱数量、方向、形状及长度均有变化,表现为长度变化(28.6%);分裂(4.3%);联合(2.9%);方向变化(1.4%);形状变化(1.4%)。并且治疗后腭皱远中端点的前后向位移变化占45.7%,近远中向位移占40%;而腭皱近中端在在前后向和在近远中向上位移变化分别为32.9%和17.1%。(2)正畸治疗前组及正畸治疗后组不同个体均未发现相同的腭皱模式。(3)正畸治疗前、后模型的腭皱平均正确配对率为92.19%。而治疗后模型与复制后模型的腭皱平均正确配对率是99.05%。结论腭皱形态具有高度的个体特异性,尽管正畸治疗后腭皱的形态有一定变化,但仍可作为一种新的方法应用于法医齿科的同一认定。