Banknote characterization using the FTIR spectroscopy

Counterfeit methods are more sophisticated than ever before, so it is necessary to implement as many different methods as possible to get reliable information on the origin of the banknotes. The FTIR spectroscopy provides exactly this, a different approach to the identification of different banknote components, from the paper itself to the characterization of the inks, holograms and watermarks. This paper examines the similarities and differences in the composition of the paper used for making banknotes in six different currencies, and at the same time deals with the characterization of the unique features of a particular currency. Moreover, the consistency within the particular currency is examined by comparing multiple banknotes of the same denomination

The Possibility of Increasing the Achromatic Tone Values of FOGRA 51 Standards Achieved by the Modification of in Line Pre-Treatment of the Printing Substrate

For high-quality black & white printing realized with an electrophotography printing machine, it is necessary to prepare the printing substrate. For optimal adhesion of the black liquid electrophotography ink to the printing substrate, it is necessary to apply additional treatment to meet ideal substrate surface tension by means of corona treatment and/or coating with fluid for regulating the surface tension (primer). This paper examines the influence of the corona power and the thickness of used fluid for the regulation of surface tension on the achromatic digital reproduction quality. Within the electrophotography printing process, this implies determining the differences in the colour gamut volume, the structure of characteristic screening elements, the amplitude-modulated screening, and the increase in the number of colour separations. The results show that the optimal colour tone values, colour gamut, and dot gain, high quality of digital prints will be realized without the use of the fluid for the regulation of surface tension and without activation of the corona power. That confirms that the FOGRA values for industrial standards can be used for quality electrophotography printing

Computer Generated Holograms of 3D Points Cloud

Computer generated holography is a method of using numerical methods to simulate the physical processes underlying a real hologram’s optical recording and reconstruction i.e. the method of digitally generating holographic interference patterns. As such, it represents substantial progress compared to classical holography. A major disadvantage of this approach is the absence of specialized software tools for computer generated holograms and extremely high computer resource consumption, resulting in an excessive computing time. The goal of this paper is to create a physically plausible computer model for generating holograms, with a large potential for calculation optimization and acceleration, as well as the integration of this model into simple hologram creation software. We made software that simulates wave optics using previously known physical model to generate a hologram with the possibility of connection with commercial 3D tools via .obj documents. Considering that there is a problem of high computing resources consumption and time we have incorporated in our software the possibility of a parallel calculation for the purpose of testing, further software development and customization to optimize the computer generation of holograms

Press - world milestone and Croatia

The machine printing and rapid cultural development in Europe begins with the discovery of metal lettering at the end of the 15th century. This printing technique has been named the letterpress printing and is one of the greatest inventions of mankind. The development of printing was one of the main indicators of the development of individual countries. We believe that today in the world and in Europe the Croatian development of that age is significantly neglected. This paper presents European development and development in Croatia. This paper will contribute to a more accurate evaluation of Croatian printing and cultural level of that time by displaying Croatian achievements of that era, the printing staff, printed works and printing houses, throughout European and Croatian development of printing

Magenta and alternative red colour spectroscopy on nautical charts in the visible and near-infrared electromagnetic spectrum

The International Hydrographic Organization (IHO) publishes Regulations and Technical specifications for the official nautical charts in order to standardize the use of colours to all hydrographic offices of IHO Member States. The use of magenta is reserved for highlighting, drawing attention and to distinguish information to elements of a chart of maritime importance and it is necessary to ensure its visibility.So far, there is no information on the spectrographic composition of colours intended to highlight specific content. For the first time, spectroscopy of magenta and alternative red colour is performed on the charts of hydrographic offices that have officially published colour compositions. Spectroscopy extends beyond the visible area to the near-infrared part of the electromagnetic spectrum. The article presents the absorption curves of magenta and red colour that contain information on the spectrographic composition of these colours in the visible and near-infrared spectrum. The purpose of the study is to show what proportion of black colour added to magenta or red can give positive response or positive absorption properties in the near-infrared part of the spectrum. The results are also part of preparatory research aimed at introducing colour twins, a system of hidden graphical elements designed to protect nautical charts from forgery and to expand their information content

Modeling light dispersion in the printing substrate within the Monte Carlo method

Proizvodni značaj optičkih svojstava papira motivirao nas je na izgradnju teorijskog pristupa koji se može koristiti za određivanje refleksije i disperzije svjetla od površine papira. U radu smo prezentirali metodu temeljenu na Monte Carlo modelu raspršenja svjetlosti za bolje razumijevanje nastanka optičkog prirasta rastertonskih vrijednosti, te kako bi osigurali realističniji opis medija u kojem se raspršenje svjetlosti događa. Monte Carlo metoda je služila kao okvir unutar kojeg smo bili u mogućnosti opisati difuzno raspršenje svjetlosti koja doživljava višestruke podpovršinske refleksije i apsorpcije na komponentama od kojih je papir sačinjen. Naše simulacije pružaju fleksibilan i u isto vrijeme, strog pristup transportu svjetlosti u mediju kao što je papir. Numerički smo istražili učinke modelirane površine na optička svojstva papira zbog podpovršinskog raspršenja svjetlosti.Manufacturing significance of optical properties of paper motivated us to construct a theoretical approach which could be used to determine the reflection and dispersion of light from paper surface. We introduced a method based on the Monte Carlo model of light scattering in paper for better understanding the origin of optical screen values gain and to provide a more realistic description of the medium in which light scattering occurs. The Monte Carlo method was used as a frame within which we were able to describe the diffuse scattering of light which suffers multiple subsurface reflections. Our simulation provides a flexible and at the same time rigorous approach to the transport of light in a medium such as paper. We numerically investigated the effects of the modeled surface on the optical properties of paper throughout subsurface light scattering

Anisotropic Mechanical Properties of Materials in Stereolithographic Additive Manufacturing

Rapid development and expanding deployment of additive manufacturing mark this technology as an acceptable alternative to traditional methods of production in terms of speed and quality. All types of additive manufacturing technologies build objects layer by layer, therefore anisotropy of mechanical properties is often encountered, making it difficult to accurately predict the mechanical behavior of additively manufactured parts. This paper examines the mechanical properties of additively manufactured parts and the creation of an anisotropic digital material model that can be used to accurately simulate the behavior of additively manufactured parts using FEA (Finite Element Analysis). A three-point bending test was performed on samples created using SLA (Stereolithography) technology. The identical bending scenario was computer modeled using FEA, while the modified manufacturer\u27s data was used for digital material creation. Comparison and analysis of the experimentally obtained results and the results of the FEA were performed

UTJECAJ SLUŠNE KONTROLE NA TRAJANJE IZGOVORA GLASNIKA

U istraživanju se ispitivalo kako izostajanje slušne kontrole utječe na trajanje izgovora glasnika. Dvanaest je ispitanika uvježbalo 5 stupnjeva trajanja samoglasnika /a/ i suglasnika /t/t a zatim izgovaralo ta trajanja s potpunom, djelomičnom slušnom kontrolom i bez nje. U pokusu nije bilo modela koji bi ispitanici oponašali, nego su oni sami uspostavili sustav od 5 trajanja svakoga glasnika, od najkraćeg (što mogu izgovoriti) do najdužeg, s minimalnim, ali čujnim razlikama. Pretpostavljeno je da će se s ukinućem slušne kontrole, što se postiglo zaglušivanjem bijelim šumom, trajanje glasnika skratiti. Rezultati istraživanja pokazali su da se s izostajanjem slušne kontrole izgovor samoglasnika dulji, a suglasnika krati. Potpun izostanak slušne kontrole manje je utjecao na suglasnik, nego na samoglasnik. Pokazalo se također da se s većom točnošću izgovaraju pojedina trajanja samoglasnika

Image noise and tone transfer function of imaging systems

Prilikom reprodukcije i stvaranja slike dolazi do očekivane pogreške prilikom prenošenja informacije s jednog reprodukcijskog sustava na drugi. Ta pogreška naziva se šum u reprodukciji, a posljedica je samih reprodukcijskih sustava. U ovom je radu obrađena pojava šuma u reprodukciji na otisnutim materijalima te korelacija između tonskih vrijednosti piksela originala i gustoće zacrnjenja reprodukcije za više osobnih pisača. U radu je korišten uzorak tonske skale (KODAK Gray Scale) te je reproduciran na tri različita pisača. Ono što je u originalnoj datoteci bila tonska vrijednost pojedinog piksela, u reprodukciji se pojavljuje kao gustoća zacrnjenja, odnosno refleksija. Skeniranjem uzorci su prevedeni u digitalni oblik, te uz pomoć mnogih softverskih alata analizirani. Uočeno je da postoji razlika između ulaznih vrijednosti originala i izlaznih vrijednosti na reprodukciji te obzirom na te vrijednosti zaključeno je da je moguće rekonstruirati TTF (Tone Transfer Function, prijenosna funkcija tonova) svakog pojedinog korištenog uređaja. Upravo je TTF nužna za razumijevanje načina reprodukcije, šuma koji se u njoj javlja kao očekivana greška, te optimalizacije reprodukcijskih sustava.During reproduction and creation of an image comes to the expected error when transferring information from one reproduction system to another. This error is called reproduction noise, resulting in a very reproductive system. This paper examines the phenomenon of noise in the reproduction of the printed materials and the correlation between the tonal values of the original pixel density and opacity playing for several personal printers. In this paper is used a sample tone scale (Kodak Gray Scale) and is reproduced on three different printers. Tonal value of each pixel in the original file in the reproduction appears as density opacity or reflection. Scanning patterns are translated into digital form, and analyze them with a variety of software tools. It was noted that there is a difference between the input original values and the output reproduction values. It was noted that there is a difference between the input and output values of the original values in the reproduction, which indicates that it is possible to reconstruct the TTF (Tone Transfer Function, transfer function tones) of each used device. It is TTF that is necessary to understand the noise modes, that appears as expected error and to optimize reproductive system