公务员面试计算机评分系统中数据加密技术的研究与实现

随着我国公务员录用面试信息化建设工作的深入推进,各地陆续在公务员面试过程中采用了公务员面试计算机评分系统。该系统对考官基本信息库、考官的原始计分表、监督员（复核员）的统计表等数据的加密存贮和传输非常重要。为避免泄密,基于PKI技术的“混合签密”方案应用于面试计算机评分系统,能很好地提供机密性、完整性、可认证和不可否认性保证数据的安全性。     

关于多媒体时代公安院校加强书法教育的思考

素质教育是德育、智育、体育、美育诸育的有机组合。书法教育身兼德育、美育两大重任,其目标与素质教育“面向全体、全面发展、培养个性”的特征具有一致性,在素质教育中占有特殊的重要地位。公安院校应加强书法教育,在其课程定位、教学内容、教学方法与手段、物质保障等方面进行科学研讨、决策与实施,从而切实发挥书法教育的功能,促进公安院校学员素质的提升。     

通过笔画特征的变化判断印章印文与签名字迹先后顺序

印章印文与签名字迹先后顺序,受印泥、纸张和笔具性质等多种因素的影响,这种影响可通过签名字迹的笔画特征反映出来。对此,可以用普通40倍数光学显微镜进行检验判断。但由于原子印章所使用的盖印材质既不溶于水、草酸溶液,也不溶于有机溶剂,当签名字迹与原子印章印文相交时,其先后顺序并无明显的普遍性特征(如斑驳、变细等现象)可寻,所以,此种方法不适用于判断该类印章与签名字迹的先后顺序。     

Handwriting of the alcoholic

Alcohol intoxication produces abnormal handwriting with manifestations that are thoroughly described in the literature of forensic science. A less known phenomenon is the peculiar handwriting changes found in alcoholics, especially individuals in the later stages of the disease. In addition to the two handwriting states of non-alcoholic drinkers (normal/sober and intoxicated) the alcoholic writer has a third state, handwriting done in withdrawal. Withdrawal is a state of tension resulting in handwriting characterized by irregularity, ataxia and tremor. This type of abnormal handwriting creates special problems of authentication requiring detailed background history and appropriate comparison specimens, but it can also be used to judge the writer's state of sobriety.     

Kinship assignment with the ForenSeq™ DNA Signature Prep Kit: Sources of error in simulated and real cases

Kinship recognition between anonymous DNA samples is becoming a relevant issue in forensics, more so with the increasing number of DNA profiles in databanks. Also, NGS-based genotyping is being increasingly used in routine personal identification, to simultaneously type large numbers of markers of different kind. In the present work, we explored computationally and experimentally the performance of the ForenSeq™ DNA Signature Prep Kit in identifying the true relationship between two anonymous samples, distinguishing it from other possible relationships. We analyzed with Familias R series of 10,000 pairs with 9 different simulated relationships, corresponding to different degrees of autosomal sharing. For each pair we obtained likelihood ratios for five kinship hypotheses vs. unrelatedness, and used their ranking to identify the preferred relationship. We also typed 21 subjects from two pedigrees, representing from parent-child to 4th cousins relationships. As expected, the power for identifying the true relationship decays in the order of autosomal sharing. Parent-child and full siblings can be robustly identified against other relationships. For half-siblings the chance of reaching a significant conclusion is already small. For more distant relationships the proportion of cases correctly and significantly identified is 10% or less. Bidirectional errors in kinship attribution include the suggestion of relatedness when this does not exist (10–50%), and the suggestion of independence in pairs of individuals more than 4 generations apart (25–60%). The real cases revealed a relevant effect of genotype miscalling at some loci, which could only be partly avoided by modulating the analysis parameters. In conclusion, with the exception of first degree relatives, the kit can be useful to inform additional investigations, but does not usually provide probatory results.     

对笔迹检验中差异点的几点认识

本文通过案例分析了笔迹检验中差异点形成的原因,并提出了笔迹检验工作中必须注意的三个关系,这对于笔迹检验实践具有一定的借鉴作用。     

签名笔迹量化检验研究用实验样本的设计与收集

本文在全面说明签名笔迹特点的基础上,阐述了签名笔迹特征层次结构模型的核心内容,重点探讨开展签名笔迹量化检验研究用实验样本的方案设计,收集方法与范围。同时,提出实验样本的设计与搜集应本着“贴近实战,服务办案”的原则,并具体设计了签名笔迹量化检验研究用实验样本的设计方案与具体内容,提出广泛收集具有代表性实验样本的具体要求。另外,提出了研究用实验样本筛选方法和扫描输入计算机具体要求。科学合理的设计与收集签名笔迹量化检验研究用实验样本,才能确保签名笔迹量化检验研究具体分析与统计结果的科学性和实用性。     

Characteristics of erasable ball point pens

In 1979 shortly after the introduction of the erasable ball point pen two papers were published describing its basic characteristics (W.J. Flynn, J. Police Sci. Adm., 7 (1979) 346–349; P. Pfefferli and J. Mathyer, Rev. Int. Criminol. Police Tech., (1979) 407–419). Since that time two additional makes of pens and other colors of ink have been introduced, and the quality of writing has been significantly improved.The ink of the erasable pen differs significantly from that of the standard ball point pen, and for that matter from ink of all other modern day pens. In what way might this newer pen produce a written line different from other ball point pens? This is one question that the paper addresses with limited success.When erased, what techniques can be used to attempt to determine the text of the original writing? The writer considers all standard methods for deciphering erased writing and discusses modification by use of infrared film with oblique light photography — the method most successful in determining the original contents of the erasure.     

Detection and analysis of DNA mixtures with the MiSeq FGx®

Recognizing and interpreting mixtures are challenges that occur frequently in forensic casework. Therefore, any new analysis methods that are implemented must handle the challenges of mixed forensic samples. Next generation sequencing offers advantages over capillary electrophoresis in amplicon multiplexing and degraded sample analysis; however, advantages with mixed samples rely heavily on the advancement of user-friendly analysis software. This research analyzed samples with the ForenSeq™ DNA Signature Prep Kit on the MiSeq FGx® and compared them with the GlobalFiler™ STR Kit for capillary electrophoresis. Metrics tested for both chemistries included concordance, limits of detection, and mixture analysis. Data analysis for mixture samples was completed with the MixtureAce™ plug-in and ArmedXpert™ software. Next generation sequencing offered distinct advantages in limits of detection and isoallele heterozygosity but suffered from increased variability in stutter and allele count ratios compared to capillary electrophoresis.     

The probative character of Forensic Handwriting Examiners’ identification and elimination opinions on questioned signatures

This 5-year study investigated the character of Forensic Handwriting Examiners’ (FHEs) authorship opinions on questioned signatures through the medium of blind validation trials. Twenty-nine thousand eight hundred and eleven authorship opinions were expressed by FHEs on trial kits comprising randomized questioned genuine signatures (written by the specimen writer), disguised signatures (written by the specimen writer) and simulated signatures (not written by the specimen writer). Results showed that, as a group, FHEs were significantly more confident at identifying writers’ genuine signatures than identifying writers’ disguised signatures or eliminating specimen writers from having authored simulated signatures. It is proposed that the difference in FHE confidence arises from the difficulty they have in deciding which alternative authorship explanation accounts for perceived combinations of similar and dissimilar features between specimen and questioned signatures.