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1.
This article presents an analysis of handwritten signature dynamics belonging to two authentication groups, namely genuine and forged signature samples. Genuine signatures are initially classified based on their relative size, graphical complexity, and legibility as perceived by human examiners. A pool of dynamic features is then extracted for each signature sample in the two groups. A two‐way analysis of variance (ANOVA) is carried out to investigate the effects and the relationship between the perceived classifications and the authentication groups. Homogeneity of variance was ensured through Bartlett's test prior to ANOVA testing. The results demonstrated that among all the investigated dynamic features, pen pressure is the most distinctive which is significantly different for the two authentication groups as well as for the different perceived classifications. In addition, all the relationships investigated, namely authenticity group versus size, graphical complexity, and legibility, were found to be positive for pen pressure.  相似文献   

2.
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.  相似文献   

3.
Forensic document examiners (FDE) called upon to distinguish a genuine from a forged signature of an elderly person are often required to consider the question of age‐related deterioration and whether the available exemplars reliably capture the natural effects of aging of the original writer. An understanding of the statistical relationship between advanced age and handwriting movements can reduce the uncertainty that may exist in an examiner's approach to questioned signatures formed by elderly writers. The primary purpose of this study was to systematically examine age‐related changes in signature kinematics in healthy writers. Forty‐two healthy subjects between the ages of 60–91 years participated in this study. Signatures were recorded using a digitizing tablet, and commercial software was used to examine the temporal and spatial stroke kinematics and pen pressure. Results indicated that vertical stroke duration and dysfluency increased with age, whereas vertical stroke amplitude and velocity decreased with age. Pen pressure decreased with age. We found that a linear model characterized the best‐fit relationship between advanced age and handwriting movement parameters for signature formation. Male writers exhibited stronger age effects than female writers, especially for pen pressure and stroke dysfluency. The present study contributes to an understanding of how advanced age alters signature formation in otherwise healthy adults.  相似文献   

4.
This study explored digital dynamic signatures containing quantifiable dynamic data. The change in data content and nature necessitates the development of new data treatment approaches. A SignPad Omega digitizing tablet was used to assess measurement reproducibility, as well as within‐writer variation and the occurrence of correctly simulated features. Measurement reproducibility was found to be high except for pressure information. Within‐writer variation was found to be higher between days than on a same day. Occurrence of correct simulation was low for features such as signature size, trajectory length, and total signature time. Feature discrimination factors combining within‐writer variability and the occurrence of correctly simulated features were computed and show that signature size, trajectory length, and signature time are the features that perform the best for discriminating genuine from simulated signatures. A final experiment indicates that dynamic information can be used to create connections between simulation cases.  相似文献   

5.
Eye tracking was used to measure visual attention of nine forensic document examiners (FDEs) and 12 control subjects on a blind signature comparison trial. Subjects evaluated 32 questioned signatures (16 genuine, eight disguised, and eight forged) which were compared, on screen, with four known signatures of the specimen provider while their eye movements, response times, and opinions were recorded. FDEs' opinions were significantly more accurate than controls, providing further evidence of FDE expertise. Both control and FDE subjects looked at signature features in a very similar way and the difference in the accuracy of their opinions can be accounted for by different cognitive processing of the visual information that they extract from the images. In a separate experiment the FDEs re-examined a reordered set of the same 32 questioned signatures. In this phase each signature was presented for only 100 msec to test if eye movements are relevant in forming opinions; performance significantly dropped, but not to chance levels indicating that the examination process comprises a combination of both global and local feature extraction strategies.  相似文献   

6.
The aims of this study were to determine if dynamic parameters (duration, size, velocity, jerk, and pen pressure) differed for signing style (text-based, stylized, and mixed) and if signing style influences handwriting dynamics equally across three signature conditions (genuine, disguised, and auto-simulation). Ninety writers provided 10 genuine signatures, five disguised signatures, and five auto-simulated signatures. All 1800 signatures were collected using a digitizing tablet resulting in a database of each signature's dynamic characteristics. With genuine signatures, there were significant differences between styles for size, velocity, and pen pressure, and there were significant differences between genuine signatures and at least one of the un-natural signature conditions for all parameters. For velocity and size, these changes with condition were dependent on style. Changes with condition for the other parameters were similar for the three styles. This study shows that there are differences among natural signature styles and disguise behaviors that may be relevant in forensic signature examinations.  相似文献   

7.
A prototype using simple mathematical treatment of the pen pressure data recorded by a digital pen movement recording device was derived. In this study, a total of 48 sets of signature and initial specimens were collected. Pearson's correlation coefficient was used to compare the data of the pen pressure patterns. From the 820 pair comparisons of the 48 sets of genuine signatures, a high degree of matching was found in which 95.4% (782 pairs) and 80% (656 pairs) had rPA > 0.7 and rPA > 0.8, respectively. In the comparison of the 23 forged signatures with their corresponding control signatures, 20 of them (89.2% of pairs) had rPA values < 0.6, showing a lower degree of matching when compared with the results of the genuine signatures. The prototype could be used as a complementary technique to improve the objectivity of signature examination and also has a good potential to be developed as a tool for automated signature identification.  相似文献   

8.
The current research explores six hypotheses derived from the well-known procedural justice-based model of legitimacy in two different religious groups in Israel, and adds to the model the effect of religiosity on the perceived legitimacy of rules and institutions of social control. Our results, based on data from a representative sample of 1,216 Israeli Jews and Arabs, provide general support for the hypotheses. We found that the social order is perceived as less legitimate by the Arab minority compared with the Jewish majority, and by highly religious members of the Jewish majority compared with those who are less religious.  相似文献   

9.
Development of digital image‐editing programs has enabled us to be widely exposed to forged digital images surrounding us. Such forged images have been dispersed through the Internet, newspaper articles, and magazines, and in particular, the information contained in these unverified images happened to be regarded as true. As a result, the forged images provided wrong information for individuals and society, thus sometimes creating social issues. In order to solve such problems, this study was aimed to suggest the methods of identifying the veracity of forged images. In this way, it suggested re‐interpolation algorithm. Namely, the study re‐interpolated in identical arbitrary values both the interpolated and un‐interpolated regions based on the interpolation used a lot in forged, confirmed discrete fourier transform (DFT) characteristics of these two regions, and embodied a detection map for the final forged images, using the subtraction value between two regions in DFT characteristics.  相似文献   

10.
Identification of individual by signature examination could be improved by the lateral palm print examination. By the use of new technique discussed by the author in this paper, the forensic expert can find out very useful information about the writer of writings even without going into the depth of questioned document/signature examination and without the formal or informal handwriting exemplars. The document expert with little more knowledge of the palm print can identify whether the signature is done by hand/leg/anything else, whether the author is right handed or left handed, the approximate age of the author, whether the signature is genuine or forged. Such information of author would be very much useful in elimination of the list of suspects of anonymous letters. In order to fix the authorship, standard and disputed lateral palm prints can be examined either with photographic superimposition technique or with the statistical study of the outline of the lateral palm print or with the standard method as implied in fingerprint examination. The evidential value of such lateral palm print can be placed at par with the finger prints in the court of law and could be placed right on the top of all other scientific evidences.  相似文献   

11.
It has previously been shown that forensic document examiners (FDEs) have expertise in providing opinions about whether questioned signatures are genuine or simulated. This study extends the exploration of FDE expertise by evaluating the performance of eight FDEs and 12 control subjects at identifying signatures as either forgeries or the disguised writing of a specimen provider. Subject eye movements and response times were recorded with a Tobii 1750 eye tracker during the signature evaluations. Using a penalty scoring system, FDEs performed significantly better than control subjects (t = 2.465, p = 0.024), with one FDE able to correctly call 13 of the 16 test stimuli (and three inconclusive calls). An analysis of eye movement search patterns by the subjects indicated that a very similar search strategy was employed by both groups, suggesting that visual inspection of signatures is mediated by a bottom up search strategy. However, FDEs spent greater than 50% longer to make a decision than the control group. The findings are suggestive that for some stimuli FDEs can discriminate between forgeries and disguises, and that this ability is due to a careful inspection and consideration of multiple features within a signature.  相似文献   

12.
当前,与印文鉴定相关的并在鉴定实践中经常遇到的新问题和难点问题有高仿真印文的鉴定、变造印章问题、利用真实印文变造文件、同版印章印文、朱墨时序等,本文就高仿真印文的鉴定进行了系统阐述,介绍了各种高仿真印文,包括各种高仿真印章的盖印印文、复制印文、转印印文的伪造手段及其特点,并提出了高仿真印文的鉴定思路和要点。  相似文献   

13.
14.
The author proposes a nondestructive and highly precise method of measuring the thickness of a film pasted on a passport using a confocal-type laser profile microscope. The effectiveness of this method in passport examination is demonstrated. A confocal-type laser profile microscope is used to create profiles of the film surface and film–paper interface; these profiles are used to calculate the film thickness by employing an algorithm developed by the author. The film thicknesses of the passport samples—35 genuine and 80 counterfeit Japanese passports—are measured nondestructively. The intra-sample standard deviation of the film thicknesses of the genuine and counterfeit Japanese passports was of the order of 1 μm The intersample standard deviations of the film thicknesses of passports forged using the same tools and techniques are expected to be of the order of 1 μm. The thickness values of the films on the machine-readable genuine passports ranged between 31.95 μm and 36.95 μm. The likelihood ratio of this method in the authentication of machine-readable Japanese genuine passports is 11.7. Therefore, this method is effective for the authentification of genuine passports. Since the distribution of the film thickness of all forged passports was considerably larger than the accuracy of this method, this method is considered effective also for revealing the relation among the forged passports and acquiring proof of the crime.  相似文献   

15.
This paper reports on the performance of forensic document examiners (FDEs) in a signature comparison task that was designed to address the issue of expertise. The opinions of FDEs regarding 150 genuine and simulated questioned signatures were compared with a control group of non-examiners' opinions. On the question of expertise, results showed that FDEs were statistically better than the control group at accurately determining the genuineness or non-genuineness of questioned signatures. The FDE group made errors (by calling a genuine signature simulated or by calling a simulated signature genuine) in 3.4% of their opinions while 19.3% of the control group's opinions were erroneous. The FDE group gave significantly more inconclusive opinions than the control group. Analysis of FDEs' responses showed that more correct opinions were expressed regarding simulated signatures and more inconclusive opinions were made on genuine signatures. Further, when the complexity of a signature was taken into account, FDEs made more correct opinions on high complexity signatures than on signatures of lower complexity. There was a wide range of skill amongst FDEs and no significant relationship was found between the number of years FDEs had been practicing and their correct, inconclusive and error rates.  相似文献   

16.
Since Hobbes (1957 [1651] and Beccaria (1963 [1764]), scholars have theorized that the emotion of fear is critical for deterrence. Nevertheless, contemporary deterrence researchers have mostly overlooked the distinction between perceived sanction risk and fear of apprehension. Whereas perceived risk is a cognitive judgment, fear involves visceral feelings of anxiety or dread. Equally important, a theory explicating the influence of deterrence on both criminal propensity and situational offending has remained elusive. We develop a theoretical model in which perceived risk and fear are distinguished at both the general and situational levels. We test this theoretical model with data from a set of survey‐based experiments conducted in 2016 with a nationwide sample of adults (N = 965). We find that perceived risk and fear are empirically distinct and that perceived risk is positively related to fear at both the general and situational levels. Certain background and situational factors have indirect effects through perceived risk on fear. In turn, perceived risk has indirect effects through fear on both criminal propensity and situational intentions to offend. Fear's inclusion increases explanatory power for both criminal propensity and situational offending intentions. Fear is a stronger predictor than either self‐control or prior offending of situational intentions to offend.  相似文献   

17.
A video can be manipulated using synthetic zooming without using the state-of-the-art video forgeries. Synthetic zooming is performed by upscaling individual frames of a video with varying scale factors followed by cropping them to the original frame size. These manipulated frames resemble genuine natural (optical) camera zoomed frames and hence may be misclassified as a pristine video by video forgery detection algorithms. Even if such a video is classified as forged, forensic investigators may ignore the results, believing it as part of an optical camera zooming activity. Hence, this can be used as an anti-forensic method which eliminates digital evidence. In this paper, we propose a method for differentiating optical camera zooming from synthetic zooming for video tampering detection. The features used for this method are pixel variance correlation and sensor pattern noise. Experimental results on a dataset containing 3200 videos show the effectiveness of the proposed method.  相似文献   

18.
B. Found  D.K. Rogers   《Science & justice》2005,45(4):199-206
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.  相似文献   

19.
This article represents an analysis of the literature on sex‐based selection processes in the criminal justice system. It is only since the feminist wave of the sixties that sexual discrimination has been considered as an issue of importance in the study of the criminal justice system and that female criminality has been looked at more thoroughly. The article deals with the different assumptions and hypotheses which have come forward in the debate on the possible discrimination of men and women in the criminal justice process. In the first part of the article the various theoretical models are outlined: the chivalry and evil women hypotheses, the legal or etiological model, the social control theory, the family‐based justice model, and a multifactoral model. In the second part of the article, the results of empirical research relevant to these hypotheses are presented. American, British, Belgian, Dutch and some German literature has been taken into account. The review of the literature shows that the chivalry hypothesis cannot offer an all‐embracing explanation for the possibly perceived preferential treatment of women. Similar conclusions can be drawn for the explanatory value of the legal model. Although a more lenient treatment of women can sometimes be explained by legal factors, these factors can offer no more than a partial explanation for observed sex differences in the criminal justice system. Especially in the case of pre‐trial release and sentencing, more particularly when deciding whether or not to send a defendant to prison, a noticeable sex‐effect can still be found. In the literature we find strong suggestions — although not always confirmed — that an (initially observed) more lenient treatment of women at these stages can be explained by stereotypes and expectations about the personality of women as less dangerous and the specific role which women fulfill in western society.  相似文献   

20.
In this paper, we propose an algorithm for detecting frame deletion in HEVC-coded video in the compressed domain. Specifically, we focus on the frame type changes occurring upon frame deletion, which cause slight differences between the coding patterns in original and forged video. Then, we identify discriminating coding patterns for use as features, which are classified by machine learning classifiers. Furthermore, we propose video sequence integrity detection on a group-of-picture basis, which is computationally efficient and robust even when applied to static videos and videos with genuine scene changes. The experimental results show that the proposed technique can classify HEVC-coded videos more accurately than previous methods. In addition, the results demonstrate that the selected features work harmoniously in discrimination and that the learning-based classifiers are more robust and reliable than model-based classifiers.  相似文献   

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