No description available.

Univ., Diss.--Karlsruhe, 1999.

Darmstadt, Techn. Universiẗat, Diss., 2000. / Dateiformat: tar.gz, Dateien im PDF-Format.

No description available.

Cam mechanisms are widely utilized for automatic devices in production lines, and the important influences for accuracy of out motions are the kinematic characteristics of follower motions. In order to realize and analyze the influence of the error in manufacturing processes, this research is going to analyze the planar cam-follower motion curve by using the reverse function in a measuring system. The goal of this research is to improve the measuring accuracy and efficiency in a cam measuring system. Results obtained by applying the developed measuring system also compared to those obtained by using a coordinate measuring machine.

published_or_final_version / Industrial and Manufacturing Systems Engineering / Doctoral / Doctor of Philosophy

No description available.

No description available.

The aim of this study was to illustrate an unexplored illegal exploitation of legal businesses, with the purpose of limiting this market and especially the related transactions. The issue of transactions regarding illegal material executed with credit cards was solved through involving the companies who issues the credit cards, making the market more transparent and thus preventing this kind of transactions. The thesis will illustrate how cryptocurrencies, such as Bitcoin, are being exploited regarding illegal transactions and more specifically, transactions regarding selling and purchasing Child Abusive Material within file hosting services (cyberlockers). The analyzed data was gathered using a webcrawler and different methods for analyzing correlation were implemented on the data to find relationships between different data points. The data points were then clustered, using an algorithm to create a relationship network. The developed model analyzed the data to identify trends and patterns regarding the illegal transactions and the results can be used to find the most prominent users who are potential perpetrators that actively distributes illegal material. A deeper analysis is then performed on the, according to the model, most interesting users in an attempt to identify their underlying identity. When cryptocurrencies are used by perpetrators to pay and get paid for illegal material, the transaction flows cannot immediately be connected to specific identities and therefore it is required to first identify potential perpetrators and track their transactions, to later compare them with the transactions that has already been identified as payments for illegal material. Apart from this model, a framework has been created to identify certain patterns and trends regarding the cyberlockers’ transaction flows. This was performed through analysis of the transaction flows connected to cyberlockers that were suspected to contain Child Abusive Material or other illegal material. With the results from the first and second model, the most interesting cyberlockers for future investigations were discovered, according to the trends and patterns in their surrounding transaction flows. When that analysis was performed and the first model was implemented, potential perpetrators was identified through collaborations between the investigating unit, the Police, the cyberlockers in question and the relevant exchange services. Through this collaboration the identities of the perpetrators are revealed and the transaction flows can then be analyzed to limit further distribution of Child Abusive Material within cyberlockers and consequently limit the illegal transactions with cryptocurrencies. Keywords: Bitcoin, Child Abusive Material, Cyberlockers, Illegal payments, Cryptocurrency, Webcrawler, Correlation, Relationship network.

New CAD/CAM materials are becoming more accepted in veneer restoration. The objective is to investigate the margin integrity of CAD/CAM veneer, their color masking over dark backgrounds and shear bond strength (SBS) to resin cements. Materials and Methods: Four types of CAD/CAM materials shaded A2: Lava Ultimate (LU); IPS Empress CAD (IPS); Vita Enamic (VE); and Vitablocs Mark II (VMII) were sectioned into tiles of different thicknesses: 0.3mm, 0.5mm and 0.7mm (n=7). The color (CIE - L*a*b*) of each specimen was measured against grey background, then against each tooth-shaded background: A3, A4, B3 and C2 acrylic (Coldpac, Motloid). Color differences (ΔE) were calculated. Specimens were measured against black then white background to calculate translucency. Two-way ANOVA was used to compare the differences in ΔE among the groups (a=0.05). SBS values of 2mm thick tile specimens of the same CAD/CAM materials to resin cements, RelyX Ultimate and Varilonik Veneer, were measured using Instron Universal Testing Machine. (n=10). Statistical analysis was performed by ANOVA with Tukey-Kramer HSD multiple comparison test (a=0.05). Qualitative evaluation of margin integrity of the veneers milled from the same CAD/CAM materials in three thicknesses 0.3, 0.5 and 0.7mm were observed under the optical microscope. Results: Significant differences in masking capabilities were found among the tested material for all three thicknesses. In comparison of ΔE values of the tested materials over tooth-shaded backgrounds, specimens over shade A3 background showed the highest color masking ability. LU and VE exhibited better color masking than IPS and VMII. IPS showed significantly higher in translucency than the other groups. IPS showed the highest SBS to resin cements and LU showed lowest SBS. Materials cemented with RelyX showed significantly higher SBS values than those with Variolink. CAD/CAM milled LU and VE veneers show smoother margins when compared to IPS and VMII. Conclusion: LU and VE exhibited higher color masking, lower translucency, lower SBS values, and better margin integrity than IPS and VMI. / 2019-09-26T00:00:00Z