ABSTRACT:

Forgeries of coins can either be contemporary or modern. Already in the Middle Ages, it was well known that bracteates were considerably more difficult to counterfeit than two-faced coins. The main reason is that bracteates are struck with a more complicated technology originating from goldsmithing. Therefore, most bracteate forgeries have been produced since the eighteenth century. Compared to original bracteates, modern bracteate forgeries often have the following characteristics: 1) an incorrect weight; 2) a lower relief; 3) sharper contours on the reverse; 4) an artistically clumsy design; 5) evidence of being struck with the same die if there are several specimens; and/or 6) empty fields in the background.

In this article Author discusses the problem of false interpretations of the earliest history of the Slavic people undertaken by Polish 19th century historians. He also analyses the attitude of various historians towards their colleagues' forgeries.

The copy-move forgery detection (CMFD) begins with the preprocessing until the image is ready to process. Then, the image features are extracted using a feature-transform-based extraction called the scale-invariant feature transform (SIFT). The last step is features matching using Generalized 2 Nearest- Neighbor (G2NN) method with threshold values variation. The problem is what is the optimal threshold value and number of keypoints so that copy-move detection has the highest accuracy. The optimal threshold value and number of keypoints had determined so that the detection has the highest accuracy. The research was carried out on images without noise and with Gaussian noise.

This paper addresses the problem of tampering detection and discusses methods used for authenticity analysis of digital audio recordings. Presented approach is based on frame offset measurement in audio files compressed and decoded by using perceptual audio coding algorithms which employ modified discrete cosine transform. The minimum values of total number of active MDCT coefficients occur for frame shifts equal to multiplications of applied window length. Any modification of audio file, including cutting off or pasting a part of audio recording causes a disturbance within this regularity. In this study the algorithm based on checking frame offset previously described in the literature is expanded by using each of four types of analysis windows commonly applied in the majority of MDCT based encoders. To enhance the robustness of the method additional histogram analysis is performed by detecting the presence of small value spectral components. Moreover, computation of maximum values of nonzero spectral coefficients is employed, which creates a gating function for the results obtained based on previous algorithm. This solution radically minimizes a number of false detections of forgeries. The influence of compression algorithms' parameters on detection of forgeries is presented by applying AAC and Ogg Vorbis encoders as examples. The effectiveness of tampering detection algorithms proposed in this paper is tested on a predefined music database and compared graphically using ROC-like curves.

The paper is a case study investigating the nominal and adjectival morphology in the English text of bounds to S 179, a post-Conquest forgery. The aim of the study is to determine what linguistic means of authentication were applied by an eleventh- century forger who devised a text which was supposed to look 200 years old at the time of its production, as well as to search for modern features which give the forgery away, at the same time allowing an insight into early Middle English. The study represents research into “transitional”, post-Conquest English (Faulkner 2012) and the status of English under the Norman rule.