Open Access

Forming complex parts out of high and ultra-high strength aluminium alloys has proved to be more challenging in comparison to the currently used deep drawing steels. Nevertheless, aluminium alloys show a limited formability in contrast with, for example, deep drawing steels. Novel processes like Warm-forming, W-Temper or Hotforming, offer the potential to produce light and highly integrated one-piece components from such aluminium alloys at elevated temperatures. When considering aluminium alloys of the 7000 group, which can reach strength values (UTS) of about 600 MPa, crash components such as side impact bars would offer a suitable field of application. Forming at elevated temperatures, in particular with the Hotforming process, offers high potential in the production of complex structural components on the one hand and in the use of existing press hardening equipment on the other. To date, the material behaviour of aluminium alloys in the 7000 group, applied in such processes and in the later final state after forming, is not sufficiently known. Therefore, in this study, systematic investigations on the formability and the final strength during and after forming at elevated temperature of the EN AW-7075 aluminium wrought alloy from different suppliers are conducted. In general, material- and damage/ failure models were created and implemented into simulation in order to make predictions. Characterisation of the plastic material properties on the basis of various tensile specimens as shear-, notched-, tensile- and Erichsen tests are carried out to adapt the complex material- and failure models such as Barlat YLD2000 and GISSMO to the experimental values using a parameter optimisation. These were made for the material conditions during forming, i.e. after solution heat treatment, the final condition after artificial ageing at 180°C for 20 minutes, which corresponds to the cathodic dip coating, and the T6 condition, which is the highest strength condition. To evaluate a suitable friction coefficient for high temperature forming processes, anti-friction agents are screened, and the potential applicability evaluated by strip-drawing tests. Thereby, using an analytical relationship, friction coefficients are determined at room temperature and 180°C, which are used as corresponding friction model for the finite element forming simulation. Crash simulations using the nonlinear finite element method (FEM) of side impact protection beams are used to demonstrate the weight saving potential of high and ultra-high strength aluminium alloys compared to a beam made of press hardened steel. A weight saving of about 20 % could be achieved with the same crash performance. This can be significantly increased to around 30 % - 40 % by using local reinforcements such as CFRP or GFRP (carbon/ glass fibre reinforced plastic) patch. For this reason, a novel process was developed which is based on the conventional Hotforming process with an integrated thermal direct joining step called “Extended Hotforming”. Subsequently, a heatable forming tool for the production of a serial like sheet metal side impact beam was developed to validate the finite element simulation and to demonstrate the potential of the forming processes at elevated temperatures for aluminium sheet metal components.

As the amount of software source code increases, manual approaches for documentation or detection of software design patterns in source code become inefficient relative to the value. Furthermore, typical automatic pattern detection tools are limited to a single programming language. To address this, our Design Pattern Detection using Machine Learning (DPDML) offers a generalized and programming language agnostic approach for automated design pattern detection based on machine learning (ML). The focus of our evaluation was on ensuring DPDML can reasonably detect one design pattern in the structural, creational, and behavioral category for two popular programming languages (Java and C#). 60 unique Java and C# code projects were used to train the artificial neural network (ANN) and 15 projects were then used to test pattern detection. The results show the feasibility and potential for pursuing an ANN approach for automated design pattern detection.

Novel myopia control spectacle lenses induce peripheral contrast reduction via optical diffusion. It is suggested, that the contrast reduction alters retinal processes in the low-level neural circuity, leading to an inhibition of eye growth. The purpose of this thesis is to evaluate the influence of full-field contrast reduction on low-level neural processing of the retina, described by the edge contrast sensitivity.

Databases are becoming an ubiquitous and integral part of most software as the data era and the Internet of Everything unfolds. Alternative database types such as NoSQL grow in popularity and allow data to be stored and accessed more simply or in new ways. Thus, software developers, not just database specialists, are more likely to encounter and need to deal with databases. Virtual Reality (VR) technology has grown in popularity, yet its integration in the software development tool chain has been limited. One potential application area for VR technology that has not been sufficiently explored is database-model visualization. This paper describes Virtual Reality Immersion in Data Models (VRiDaM), a generic database-model approach for visualizing, navigating, and conveying database-model information interactively. It describes and explores both native VR and WebVR solution concepts, with prototypes showing the viability of the approach.

This research project is of particular importance since there is a lack of adequate data on pediatric eye and vision disorders in Russia, particularly in the Volga region. In the present study, we estimate the prevalence of vision disorders among school-aged children who participated in a vision screening program in Samara, Russia. The relationship between learning-related visual dysfunctions is explored in depth, such to illustrate the connection between vision and learning. Hence, a key feature in this study is the inclusion of binocular vision disorders among the conditions tested.

The increasing prevalence of myopia throughout the industrialized world in recent decades has caused costs and problems for the eye health. Changed lifestyle and behavior are the main causes. For the pathogenesis of myopia, the amount of time spent outdoor and near activities play an important role. Various options for the treatment of myopia have been described as effective in the literature. Normal single vision glasses and contact lenses can only provide clear vision, but do not reduce myopia progression. Orthokeratology shows a slowing of axial growth, but has an increased risk of infectious keratitis. Low-dose atropine (0.01%) is currently the best pharmacological option. It proved safe, effective and showed the least rebound effect with negligible side effects. Other options for the treatment of myopia include special glasses, behavioral changes and prolonged outdoor exposure (to prevent the onset of myopia), as well as other methods. An increasingly important myopia management option is multifocal contact lenses, that provide a peripheral treatment zone producing myopic defocus. Such myopia control lenses are available as customized or as daily or monthly lenses. Children benefit from wearing contact lenses more than just having refractive error correction and myopia control, they have a better self-esteem and improved quality of life. The numerous findings on the safety and efficacy of soft multifocal distance center contact lenses in children to reduce the progression of myopia suggest that this modality should be considered as a main treatment option. Less, but similar to orthokeratology, when wearing soft lenses there is a risk of developing potentially serious complications such as microbial keratitis. The introduction of child-appropriate risk minimization strategies, and patient and parent education with regular monitoring is essential and leads to successful contact lens wear. This literature review summarized the actual knowledge about myopia management, prevalence, etiology and the visual and healthy consequences of myopia. The three currently most important strategies for slowing the progression of myopia are soft multifocal distance center contact lenses, Orthokeratology and low-dose atropine ophthalmic drops.

This research looks into the question of where and how Artificial Intelligence and Big Data can be usefully implemented into Affiliate Marketing. By consulting relevant literature and qualified experts, this work identifies 6 areas, where Artificial Intelligence can be beneficial. These areas were found to be Affiliate Recruitment, Affiliate Management, Product Data Feed Optimization, Tracking, Attribution and Forecasting. The implementation of Artificial Intelligence in these areas revealed 3 advantages to the Affiliate Marketing channel: Saving of time, support of decision-making, and incentivizing of publishers. While a more detailed study of this research topic would be necessary for validating the results, the findings show that the implementation of Artificial Intelligence technology can help a business gain competitive advantage.

This paper describes an application analysis of one important topic of diversity marketing – gender marketing. With the help of two surveys and content analyses in two different media sectors – television and print media – the general trend of gender representation in advertising could be located. While most survey respondents are still using characteristics for males and females which were shaped by traditional gender roles, most of them believe that the roles from the 1950s are outdated and that the media should adapt to the changes in societies in regard to gender roles. However, the content analyses have shown that the marketers have already adapted and are primarily presenting the viewers contemporary images of men and women instead of the stereotyped ones from the 1950s. The only issue that has not changed yet is the color coding which starts to differentiate between males and females since childhood. The findings of this paper suggest that the perception and the reality do not always correspond with each other and that, although the adoption of the change of gender roles is advancing, it is still not completed yet.

Purpose: The purpose of this thesis is to provide a comprehensive literature review about albinism as an inherited metabolic disorder of melanin synthesis along with those related conditions impacting the visual system. As such, it addresses eye care emphasizing the visual consequences of albinism along with diagnostic and treatment options. Methods: Background knowledge about ocular development is given as well as information about etiological biochemical and genetic processes. The current classification, clinical findings and their assessment and management options are presented based on recent results of research. In conclusion, two case reports are described as examples of visual care options. Results: Melanin plays a big role in the retinal and chiasmal development. Melanin biosynthesis can be disrupted by different genes in various ways which leads to the current classification of albinism. Clinical findings include fundus hypopigmenta-tion, nystagmus, iris transillumination, photophobia, foveal hypoplasia, excessive chiasmal decussation, reduced visual acuity, high astigmatism (with-the-rule), strabismus and decreased stereopsis. Treatment options to improve visual acuity, fixation and binocularity are (tinted) prescription lenses and contact lenses, low vision aids, surgical procedures and vision therapy. Medication and supplementa-tion for increased pigmentation are currently being tested on mice. Conclusions: Albinism is caused by genetic mutations resulting in ocular and cutaneous hypopigmentation. It establishes various phenotypes that require different therapy approaches in order to improve vision and therefore quality of life.

A good stereopsis (depth perception) is needed in everyday life, regardless whether a person is a professional driver or chef. Good estimation of distance, and of what is further and what closer, could mean the difference between a crushed and a whole car or between a bloody and a healthy finger. The main theme of this Master thesis is detect and quantify major factors in depth perception. Do the younger estimate the depth better than the older; do they have better depth perception with greater or smaller pupil distance; does depth perception depend on gender; what happens with stereopsis when vision is fogged by +0,5 and +1,0 D? These are the questions dealt with in this Master thesis. To answer these questions measurements were made on 51 subjects (mean age 45,0 +/- 13,32 years) of whom 25 were women, mean age 45,5 +/-13,55 years (12 with PD<62 mm, mean and 13 with PD>66 mm) and 26 men, mean age 44,4 +/- 13,34 years (13 with PD<62 mm and, 13 with PD >66 mm). Each of these four groups was further divided by age (one in range 20 to 35 years and second in range 50 to 65 years). The measurements were made with a few assumptions. The first assumption was that stereopsis is in direct correlation with visual acuity, the second assumption was that persons with bigger interpupillar distance have better stereopsis, and the third assumption was that with age the stereopsis ability decreases. The measurements were done with modified Frisby–Davis test expanded from four geometrical shapes to twenty-five circles. The stereopsis was measured with full refractive correction at 4,5 and 3,0 meters. Later, stereopsis was measured with fogging with +0,5 and +1,0 D at the 4,5 and 3,0 meter distances. Statistically there is no correlation (or very weak) between stereopsis and the visual acuity for whole group of 51 test persons, but if only young test persons are taken in consideration, the correlation becomes significant, r(20)=0,566, p=0,009 at 4,5 m and r(20)=0,456, p=0,043 at 3,0 m and that matches the assumption. Stereopsis is in no or weak positive correlation with pupil distance r(51)=0,059, p=0,679, which is in total contrast to the assumption. Stereopsis is in positive correlation with age at 4,5 meters measuring distance, r(51)=0,371, p=0,007, which corresponds to assumption. In addition, stereopsis is better in females than in males by 32,5%. Based on the results it can be concluded that the stereopsis is in negative correlation with age, in positive correlation with visual acuity, females have better stereopsis than males and statistically, the correlation between stereopsis and pupil distance (PD) has not been proved. The most important conclusion is that the decreased visual acuity brings significant fall of stereopsis. A deficit in refraction of -0,50 D decreases stereo acuity by about 90% (nearly 2x) and a deficit of -1,0 D decreases stereo acuity by about 220% (about 3x). Keywords: Stereopsis, stereo acuity, depth perception, pupil distance (PD), visual acuity (VA).

Purpose: Although the frequency in which practitioners are fitting scleral contact lenses is increasing, the recommendation for proper tear layer depth (thickness) varies amongst experts. The main goal of this paper is to clinically verify the effect of varying tear layer depths on induced corneal edema during lens wear. Methods: Ten subjects with healthy eyes were fitted with scleral lenses on their right eye. Each of them was fit with two different lenses: one with an apical clearance of 200 μm and another with an apical clearance of 600 μm. They wore the lenses for 8 hours on two different days, with at least a one week wash-out period. Lenses were applied at 8 a.m. on each of the testing days. Pachymetry measurements were taken one day prior to lens wear at 4 p.m., on the day of wear prior to lens application, and after removal of the lenses at 4 p.m. Measurements were collected using both the Pentacam® HR Corneal Tomographer, as well as the Visante Anterior Segment Optical Coherence Tomographer (OCT). The apical clearance was measured using the Visante OCT at two intervals during the test day: immediately after application of the lens and immediately prior to the removal of the lens. Results: In this study, there was found to be no significant difference in corneal edematous response during lens wear between the two test groups. The study shows that the eyes with the lenses have a statistically significantly thicker cornea compared to the non-lens-wearing eye after wearing either lens for 8 hours, lying within clinically and physiologically acceptable limits. Conclusion: Our clinical results do not correlate with current theoretical calculations, which predict a greater amount of corneal swelling with increasing tear layer thickness. It has to be evaluated if the effect on corneal edema changes with longer wearing periods, larger samples or other influences. Key words: scleral (contact) lens, corneal edema, pachymetry, tear layer thickness, vaulting, apical clearance

Purpose The purpose of this study was to investigate the correlation of measured visual acuity (VA) both static and dynamic obtained with static and dynamic measuring tests, as well as, response time to visual stimulus and analysis of its influence on dynamic visual acuity. The aim was to compare the results gathered for the three age groups and analyze the possible differences. Methods The test groups consisted of 75 subjects between 10 and 60 years old, categorized in three age groups. The measurements of static and dynamic visual acuity and reaction time were conducted. The set of nine tests (five with radial magnification speed and four simulating driving condition at 72 km/h and 130 km/h) was designed in order to measure dynamic visual acuity and the set of two tests for reaction time measurement. Results Compared to static visual acuity in both tests, the results obtained with measurements of dynamic visual acuity resulted in lower values depending on Landolt ring size and magnification speed of animation. In average, the dynamic visual acuities in tests with different magnification speeds were lower than static by 0.4 visual acuity units, or 31% and the average of dynamic visual acuity after subtracting motoric component (reaction time) was for 0.2 visual acuity worse than static or 15%. In the second test simulating driving conditions at 72 km/h the average drop in dynamic visual acuity was 33% while at 130 km/h average drop for younger and middle age groups was 37% and for older group was 44% and after subtracting motor component values for 72 km/h speed simulation average drop in visual acuity values was 23% for all three groups; for 130 km/h speed simulation younger and middle aged group average drop of visual acuity was 20% and with older group it was 24%. Conclusion The tests used in this study were simple and fast and revealed significant difference between static and dynamic visual acuity and influence of reaction time on dynamic Nataša Vujko Muždalo Abstract 2 visual acuity values. It is hoped that this thesis will be a positive contribution in testing and training of dynamic visual and sensory response skill with drivers, sportsmen and people with visual-motor dysfunction. Keywords: Dynamic visual acuity (DVA), static visual acuity (SVA), reaction time (RT), motoric component, dynamic visual acuity test, reaction time test, radial increase in size

The present thesis deals with alternative powertrains, focusing on electric vehicles and hybrid vehicles and which of those alternative powertrains is considered as sustainable for the future. It explores the question, which alternative powertrain is worthwhile investing in for German automotive suppliers. The aim is to clarify which of the two powertrains is already established on the market and what the future prospects of those powertrains are. The question here is evaluated based on the analysis of current literature as well as through the use of a SWOT analysis and the use of the scoring model. As a result it is clear that there is a need for alternative powertrains and the entire automotive industry invests a lot in the development and research of alternative powertrains. According to the German Federal Government, one million electric vehicles should be on German roads by 2020. With pure electric vehicles, however, the goal will be difficult to reach. Therefore, there is a lot of vested interest in the development of hybrid vehicles on the market. It shows that the hybrid vehicle has considerable advantages over the electric vehicle and the hybrid vehicle is already seen as a transitional solution for pure electric vehicles. The hybrid vehicle is also already established in the market and has better chances on the market in the future. Therefore, it makes sense for German automotive suppliers to invest in hybrid vehicles and to focus on this market, since there the chances of success are greater and the future potential of this market is higher.

This paper aims to provide essential information about the formal aspects of the adjustment process companies in Southern Germany utilize to adjust their employees to new surroundings. In particular, it shall be investigated and defined what formal aspects are and when firms apply them. Literature shows that companies do implement language courses, intercultural trainings or provide further information about the host country before a stay abroad. Nevertheless, the phases during and after the assignment are not taken into account with the required importance. Additionally, since national culture can be broken down into different layers, the organizational culture as one layer was analyzed, too.By conducting a quantitative research among companies in Baden-Württemberg, this paper shows the different approaches for dealing with a stay abroad. Scientific literature about the topic of adjustment of globally assigned workers shall help emphasizing the need of a deeper cultural insight. Furthermore, by attempting to explain the organizations’ culture, a better understanding of the chosen training methods shall be created. Definitions in the beginning helped to understand the concept of culture, the notion and the phases of adjustment. Almost all collected data has been accessed either through JSTOR (a digital library founded to help academic libraries or publishers) or similar databases, through the companies’ websites or through the survey results it selves.The results of this research show that the phase before the stay abroad is organized well. Companies offer pre-departure training, but during and after the expatriate time a lack of support is being observed. The firms obviously underestimate the necessary help needed during the assignment and in the return phase, which is why the thesis attempts to fill this gap. Through the organizational culture, described on the companies’ webpages the author was able to draw a conclusion to the applied training methods, which results in a consistent overall picture of the described firms. Companies from the automotive sector had the highest return rate in the survey, which is why particular attention was paid to it.