A Hybrid Model Approach for Achieving the Highest Level of Matching Between the “Print and Original” in the Sheet-Fed Offset Pr

This study was designed to explore an optimized hybrid system through dual measurement approach of contrast measurement method and CIE L*a*b* measurement method to arrive a logical interface for achieving the highest matching between the print and original in sheet fed offset printing process. The work was started with the detailed study of contrast measurement, CIE L*a*b* measurement method, visual and computational intelligence based assessment and control. The master was designed in such a way that value of density and other values can be measured easily in effective way. X-Rite eXact instrument is used for capturing the readings, the 10 standard observers were selected initially by manual method and finally by using on line Fransworth-Munsell 100 Hue Colour Vision Test and visual assessments and judgement were done on X-Rite’s Macbeth Lighting Booth and their visual assessments are recorded, analyzed and represented. All the parameters like Paper, Ink, Measuring Conditions and Measuring Instruments etc. were maintained in compliance with ISO specifications. After the analysis of data, the study reached to the following main conclusion i.e. It is observed that almost in all the cases, preference of the Standard Observers are for Delta E Value leading to the higher contrast value instead of Minimum Delta E with less contrast value. Therefore the dual approach of “Hybrid System” will help us to arrive at the most convincing, measurable and perceptually acceptable print result which will be the highest (closest) match to the original by clubbing the best of “CIE Lab, Contrast Method and Standard Observers Visual Perception” as there are positives and negatives in all these three when one approaches individually. The objective of this paper was to develop a dual measurement approach of CIE Lab & Contrast to arrive at a logical inference for the highest level of matching between the original and print in the sheet fed offset printing

Currency security and forensics: a survey

By its definition, the word currency refers to an agreed medium for exchange, a nation’s currency is the formal medium enforced by the elected governing entity. Throughout history, issuers have faced one common threat: counterfeiting. Despite technological advancements, overcoming counterfeit production remains a distant future. Scientific determination of authenticity requires a deep understanding of the raw materials and manufacturing processes involved. This survey serves as a synthesis of the current literature to understand the technology and the mechanics involved in currency manufacture and security, whilst identifying gaps in the current literature. Ultimately, a robust currency is desire

Study of usability of MacAdams ellipsoids in defining quality of printing dark colours

Raznovrsne tehnologije tiskarskih procesa uzrokuju različita odstupanja u kvaliteti otisnutog grafičkog proizvoda. Etikete kao grafički proizvodi osjetljive su na takve promjene, budući najčešće predstavljaju prvi kontakt između kupca i proizvoda na koji je etiketa aplicirana. Ovo istraživanje usmjereno je na otiske kojima dominiraju tamnije boje, otisnute tehnikom ofsetnog tiska. Cilj ovih istraživanja je na osnovu spektrofotometrijskih mjerenja i vizualne ocjene kvalitete tiska, konstruirati MacAdamsove elipsoide i ustanoviti je li moguće MacAdamsovim elipsodima ustanoviti kvalitetu tiska u području tamnih boja. Nakon provedenih istraživanja, ustanovljeno je da elipsoidi pokrivaju različita područja unutar CIE L*a*b* sustava. Osim navedenog ustanovljeno je da je vizualnom procjenom moguće percipirati male promjene u tamnim bojama, ali ne u svim vrijednostima linearno. Korelacijom navedenih rezultata, zaključeno je da je prilikom ustanovljavanja kvalitete tiska tamnih boja moguće koristiti MacAdamsove elipsoide.Various technologies of printing processes induce various deviations in the quality of the printed graphic product. Labels as graphic products are sensitive to such changes, since they represent the first contact between the consumer and the product the label is applied on. This research is oriented towards imprints dominated by dark colours, printed using the offset printing technique. Goal of this research is to, based on the spectrophotometric measuring and visual evaluation of the printing quality, construct the MacAdams ellipsoids and establish whether it is possible to establish the printing quality in the area of dark colours using MacAdams ellipsoids. After conducted research it was established that the ellipsoids cover various areas within CIE L*a*b* system. By correlating the stated results, it was concluded that while establishing the printing quality of the dark colour it is possible to use MacAdams ellipsoids

REAL TIME QUALITY CONTROL OF THE HEATSET OFFSET PRINTING PROCESS

Offset lithography is one of the most common ways of creating printed materials. Compared to other printing methods, offset printing is best suited for economically producing large volumes of high quality prints in a manner that requires little maintenance. Because of the high speed and the high volume of the printing press, we have to rely on automation for press control and not just to the printer’s eye. When printing an image that has more than one color, it is necessary to print each color separately and ensure each color overlaps the others precisely. If this is not done, the finished image will look fuzzy, blurred or "out of register". To help line the colors up correctly, a system of registration is necessary. Therefore, the use of an automated real time quality control system will result in a more consistent color for the customer and less waste for the printer

Development of an image analysis system to produce a standardised assessment of print quality

A method has been developed using an image analysis system that simulates human print quality perception. Previous work in the area of print quality assessment has only produced methods that measure individual print quality variables, or assess small parts of an image. The image analysis system developed in this investigation is different from the previous work because it analyses the combined effects of different variables using neural network technology. In addition, measurements from an entire image can be obtained and the system can assess images irrespective of their shape. The image analysis system hardware consists of a monochrome CCD camera, a Matrox image acquisition board and a 200 MHz Pentium computer. A data pre-processing program was developed using Visual Basic version 5 to process the image data from the camera. The processed data was fed into a neural network so that empirical models of print quality could be formulated. The neural network code originated from the Matlab neural network toolbox. Backpropagation and radial basis neural network functions were used in the investigation. The hardware and software of the image analysis system were tested for non-impact printing techniques. Images of a square, a circle and text characters with dimensions of 1 cm or less were used as test images for the image analysis system. It was established that it was possible to identify the different printing processes that produced the simple shapes and text characters using the image analysis system. This was achieved by training the neural network using pre-processed image data. This produced multi-dimensional mathematical models that were used to classify the different printing processes. The classification of the different printing processes involved the objective measurement of print quality variables. Different printing processes can produce print that differs in print quality when assessed by observers. Therefore the successful classification of the printing processes demonstrated that the image analysis system could, in some cases, simulate human print quality perception. To consolidate on the preceding printing process identification result, a simulation of print quality perception was made. A neural network was trained using observer assessments of a simple pictorial image of a face. These face images were produced using a variety of different non-impact printing techniques. The neural network model was used to predict the outcomes of a further set of assessments of face images by the same observer. The accuracy of the predictions was 23 out of 24 for both the backpropagation and radial basis function neural network functions used in the test. The investigation also produced two possible practical applications for the system. Firstly, it was shown that the system has the potential to be used as a machine that can objectively assess the print quality from photocopiers. Secondly, it was demonstrated that the system might be used for forensic work, since it can identify different printing processes

A comparison of processing techniques for producing prototype injection moulding inserts.

This project involves the investigation of processing techniques for producing low-cost moulding inserts used in the particulate injection moulding (PIM) process. Prototype moulds were made from both additive and subtractive processes as well as a combination of the two. The general motivation for this was to reduce the entry cost of users when considering PIM. PIM cavity inserts were first made by conventional machining from a polymer block using the pocket NC desktop mill. PIM cavity inserts were also made by fused filament deposition modelling using the Tiertime UP plus 3D printer. The injection moulding trials manifested in surface finish and part removal defects. The feedstock was a titanium metal blend which is brittle in comparison to commodity polymers. That in combination with the mesoscale features, small cross-sections and complex geometries were considered the main problems. For both processing methods, fixes were identified and made to test the theory. These consisted of a blended approach that saw a combination of both the additive and subtractive processes being used. The parts produced from the three processing methods are investigated and their respective merits and issues are discussed

Reducing risk in pre-production investigations through undergraduate engineering projects.

This poster is the culmination of final year Bachelor of Engineering Technology (B.Eng.Tech) student projects in 2017 and 2018. The B.Eng.Tech is a level seven qualification that aligns with the Sydney accord for a three-year engineering degree and hence is internationally benchmarked. The enabling mechanism of these projects is the industry connectivity that creates real-world projects and highlights the benefits of the investigation of process at the technologist level. The methodologies we use are basic and transparent, with enough depth of technical knowledge to ensure the industry partners gain from the collaboration process. The process we use minimizes the disconnect between the student and the industry supervisor while maintaining the academic freedom of the student and the commercial sensitivities of the supervisor. The general motivation for this approach is the reduction of the entry cost of the industry to enable consideration of new technologies and thereby reducing risk to core business and shareholder profits. The poster presents several images and interpretive dialogue to explain the positive and negative aspects of the student process

Fabricate 2020

Fabricate 2020 is the fourth title in the FABRICATE series on the theme of digital fabrication and published in conjunction with a triennial conference (London, April 2020). The book features cutting-edge built projects and work-in-progress from both academia and practice. It brings together pioneers in design and making from across the fields of architecture, construction, engineering, manufacturing, materials technology and computation. Fabricate 2020 includes 32 illustrated articles punctuated by four conversations between world-leading experts from design to engineering, discussing themes such as drawing-to-production, behavioural composites, robotic assembly, and digital craft

Fabricate

Bringing together pioneers in design and making within architecture, construction, engineering, manufacturing, materials technology and computation, Fabricate is a triennial international conference, now in its third year (ICD, University of Stuttgart, April 2017). Each year it produces a supporting publication, to date the only one of its kind specialising in Digital Fabrication. The 2017 edition features 32 illustrated articles on built projects and works in progress from academia and practice, including contributions from leading practices such as Foster + Partners, Zaha Hadid Architects, Arup, and Ron Arad, and from world-renowned institutions including ICD Stuttgart, Harvard, Yale, MIT, Princeton University, The Bartlett School of Architecture (UCL) and the Architectural Association