声纹鉴定中普通话音素间过渡方式特征研究

不同人所讲的普通话语流中相邻音素间的过渡方式分为不同的类型。音节内辅音-元音之间、音节间元音-辅音之间的过渡方式分为清晰过渡(或停顿过渡)和模糊过渡(或缓冲过渡)两种类型;音节内元音-辅音之间的过渡方式分为间断过渡和连续过渡两种类型;音节内元音-元音之间的过渡方式分为平滑过渡、间断过渡、交错过渡和异变过渡四种类型。对同一人的发音而言,不论其相邻音素间的过渡方式属于上述哪种类型,都表现出较强的自身同一性。因此音素间的过渡方式可以作为声纹鉴定中的一类特征。     

线粒体DNA短片段复合扩增系统鉴别种属的研究

目的建立线粒体DNA短片段复合扩增体系用于种属鉴定的方法。方法提取人、牛、猪、羊、鸡的DNA,用所选的3对引物复合扩增细胞色素b基因（cyt b）片段、16srRNA基因片段和ND4基因片段,扩增产物经琼脂糖凝胶电泳检测。结果人DNA扩增产物在358bp、157bp和110bp处各出现一条带;动物DNA扩增产物均只有358bp一条带。结论线粒体DNA短片段复合扩增鉴别种属的方法可区分人源性生物检材和其它动物样本,可应用于法庭科学实践。     

犬17A STR 5色荧光检测试剂盒在警犬DNA鉴定中的应用研究

目的建立犬DNA检测方法。方法采用自主研发的多重PCR扩增体系和五色荧光（FAM、HEX、TAMRA、ROX和SIZ）自动化检测技术调查了犬DAmel和VWFX等16个STR基因座和1个性别决定基因座多态性,并计算该16个STR基因座的等位基因频率（P）、杂合度（H）、多态信息含量（PIC）和非父排除率（PE）。实验犬为11个品种231头犬。结果结果显示该16个STR位点的非父排除率（PE）和个体识别力（DP）分别为0.995026和0.999999992。结论显示研发的犬STR-DNA荧光检测试剂盒可作为犬DNA鉴定常规应用。     

某商贸大厦地基基础工程质量司法鉴定的案例介绍

通过对某大厦地基基础工程质量的司法鉴定,发现其中存在严重的质量安全隐患,为法院提供了具有高度公信力的证据,为诉讼多年的疑案划上句号做出了应有的贡献,揭露了被告偷工减料、野蛮施工的丑恶行为,保障了受害者的合法权益,有力地维护司法公正,促进社会和谐稳定。建筑工程质量司法鉴定涉及着控辩双方较大的利害关系,鉴定资料和鉴定文书的庭审质证过程必然充满着对抗情绪,司法鉴定人更加需要在本职工作中坚持科学、严谨、客观、公正的基本原则。     

外伤性癫痫法医学评定100例分析

目的探讨颅脑外伤后癫痫的法医学评定要点,提出外伤性癫痫的法医学评定依据。方法对100例颅脑损伤后癫痫患者门诊及住院病历,结合临床脑电图（EEG）结果、CT片、MRI片等影像学资料,进行了回顾性分析。结果依据GBl8667-2002《道路交通事故受伤人员伤残评定》标准有关颅脑损伤后癫痫发作类型、发作频率的相关条款规定,Ⅲ级伤残8人,Ⅴ级伤残10人,Ⅶ级伤残22人,Ⅸ级伤残40人,Ⅹ级伤残20人。误工期限、营养期限和护理期限评定结论时间长短差异较大,具有个体化特征。结论外伤后癫痫常继发于严重的颅脑损伤,其发作特点决定于颅脑外伤的部位和程度,外伤性癫痫法医学鉴定必须以外伤史及既往史为基础,结合电生理及影像学检查,综合癫痫发作类型、频率及药物控制情况作出正确的伤残等级及误工期限、护理期限、营养期限的鉴定结论。     

Author gender identification from text

Text is still the most prevalent Internet media type. Examples of this include popular social networking applications such as Twitter, Craigslist, Facebook, etc. Other web applications such as e-mail, blog, chat rooms, etc. are also mostly text based. A question we address in this paper that deals with text based Internet forensics is the following: given a short text document, can we identify if the author is a man or a woman? This question is motivated by recent events where people faked their gender on the Internet. Note that this is different from the authorship attribution problem.In this paper we investigate author gender identification for short length, multi-genre, content-free text, such as the ones found in many Internet applications. Fundamental questions we ask are: do men and women inherently use different classes of language styles? If this is true, what are good linguistic features that indicate gender? Based on research in human psychology, we propose 545 psycho-linguistic and gender-preferential cues along with stylometric features to build the feature space for this identification problem. Note that identifying the correct set of features that indicate gender is an open research problem. Three machine learning algorithms (support vector machine, Bayesian logistic regression and AdaBoost decision tree) are then designed for gender identification based on the proposed features. Extensive experiments on large text corpora (Reuters Corpus Volume 1 newsgroup data and Enron e-mail data) indicate an accuracy up to 85.1% in identifying the gender. Experiments also indicate that function words, word-based features and structural features are significant gender discriminators.     

Identification and separation of DNA mixtures using peak area information

We introduce a new methodology, based upon probabilistic expert systems, for analysing forensic identification problems involving DNA mixture traces using quantitative peak area information. Peak area is modelled with conditional Gaussian distributions. The expert system can be used for ascertaining whether individuals, whose profiles have been measured, have contributed to the mixture. It can also be used to predict DNA profiles of unknown contributors by separating the mixture into its individual components. The potential of our probabilistic methodology is illustrated on case data examples and compared with alternative approaches. The advantages are that identification and separation issues can be handled in a unified way within a single probabilistic model and the uncertainty associated with the analysis is quantified. Further work, required to bring the methodology to a point where it could be applied to the routine analysis of casework, is discussed.     

Catching the Bad Guy: Morphing Composite Faces Helps

Composite faces built by eyewitnesses commonly are poor likenesses of the target face. When there are multiple witnesses, however, an opportunity exists to morph the composites. Morphs were rated as more similar to the target face than were the mean ratings of the individual composites. However, as hypothesized, the morph also came to resemble non-target faces more than the individual composites did (a prototype effect). This prototype effect was so strong that the morphs resembled non-targets more than the individual composites resembled the targets. In addition, morphing composites produced an attractiveness bias, which made the morphing of composites less effective for less attractive targets. Even when the prototype effect and the attractiveness bias were controlled for, however, a true morph-superiority effect continued to exist. The author won the Psi Chi/APS Albert Bandura Graduate Research Award in 2005--2006 for this study.     

Y-STRs in forensic medicine: DNA analysis in semen samples of azoospermic individuals

ABSTRACT: The incidence of rape has increased, especially in metropolitan areas, such as the city of São Paulo. In Brazil, studies about it have shown that the majority of this type of crime is committed by the relatives and persons close to the victim. This has made the crime more difficult to be denounced, as only 10% of the cases are reported to competent police authorities. Usually, cytological exams are carried out in sex crime investigations. The difficulty in showing the presence of spermatozoa is frequent, but it does not exclude the presence of male DNA. The absence of spermatozoa in material collected from rape victims can be due to several factors, including the fact that the agressor suffers from azoospermia. This condition can be the result of a successful vasectomy. As the majority of DNA in the ejaculation sample is from spermatozoa, there is much less DNA to be analyzed. This study presents the application of Y‐STRs (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, and DYS393) in DNA analysis of sperm samples from 105 vasectomized men. The study demonstrated a great variation in DNA concentration. DNA extraction and amplification was possible in all sperm samples even in the absence of spermatozoa. The same profile was observed, for each individual, from DNA extracted from blood, pre‐ and postvasectomy semen samples. The use of markers specific for Y chromosome in sex crime cases, especially in the absence of spermatozoa, is very important, mainly because in most situations there is a small quantity of the agressor's DNA in the medium and a large quantity of the victim's DNA.     

Evaluation of the Suchey-Brooks method for aging skeletons in the Balkans

This study has been carried out to examine whether the Suchey-Brooks (S&B) methods could be successfully applied in age assessment of populations from the Balkans. The known-age sample consists of 33 females and 52 males pairs of pubic bones collected from the autopsy cases. Age estimation by S&B method showed an accuracy of 89.74% in males and 72.0% in females. Statistical analysis showed a positive correlation between the actual age of the investigated individuals and age phases obtained by the S&B method, although the mean values of the sixth age category differed significantly compared with the original model. The most reliable indicators in both sexes were the relief of the symphyseal surface, lipping, symphyseal rim, and dorsal margin. The discriminating power of these indicators was the least reliable in distinguishing S&B phases 2 and 3. Based on these results, the appropriate recommendations for aging Serbian populations are made. There was a good agreement between two observers (kappa=0.726).