Combinatorics in Pattern-Based Graphical Passwords

Because of increased computing power it is necessary for modern passwords to be very long and complex, this makes them hard to remember. Research show that it might be easier for people to remember visual passwords instead of textual ones. The goal of this project was to find a safe graphical password scheme which does not require any modification on the server side. A proposed solution is called the Abagram which is a system that transforms patterns on a grid into textual passwords. The main idea behind the scheme is to assign each cell in the grid a letter or a symbol. The users select some cells by passing their finger over them. The password becomes the letters of the cells in the order in which they are passed. The thesis consists of a study of the combinatorics of user-selected patterns, a theoretical security analysis of the Abagram, an analysis of a user study constructed for Android smartphones and methods for evaluating the strenght of a given pattern. The Abagram does show promise, an average pattern from the study suggest a password space with entropy of about 68 bits which is comparable with a random 10 digit password. The Abagram might be especially useful when used with a smartphone but there are still some usability and implementation aspects which must be analysed furthe

Total knee replacements: component design, pain prevention and research techniques

Bibliography: p. 142-157Some pages are in colour.Includes copy of ethics approval and copyright permission. Original copies with original Partial Copyright Licence.Total knee arthroplasty is a surgical procedure m which the knee is resurfaced with implants to relieve pam. This thesis presents computed tomography and radiography methods to determine the relative position (kinematics) for the patellofemoral and tibiofemoral joints zn vivo for a full range of motion, as well as parameters related to surgical technique. These methods were used to compare: (1) subjects with gender-specific (GS) versus traditional implant designs, (2) symptomatic versus asymptomatic subjects, and (3) static versus dynamic kinematics. Quality of life (QOL) was also measured. GS implants only had a small but significant difference in patellofemoral translation in early flexion; no other differences were found for the kinematics or QOL. For all symptomatic subjects, differences in kinematics or surgical parameters were found, suggesting the cause for the subject's postoperative pain. Static and dynamic kinematics were comparable in all but one case, where internal/external tibial rotation differed

Total Knee Replacements: Component Design, Pain Prevention and Research Techniques

Total knee arthroplasty is a surgical procedure in which the knee is resurfaced with implants to relieve pain. This thesis presents computed tomography and radiography methods to determine the relative position (kinematics) for the patellofemoral and tibiofemoral joints in vivo for a full range of motion, as well as parameters related to surgical technique. These methods were used to compare: (1) subjects with gender-specific (GS) versus traditional implant designs, (2) symptomatic versus asymptomatic subjects, and (3) static versus dynamic kinematics. Quality of life (QOL) was also measured. GS implants only had a small but significant difference in patellofemoral translation in early flexion; no other differences were found for the kinematics or QOL. For all symptomatic subjects, differences in kinematics or surgical parameters were found, suggesting the cause for the subject’s postoperative pain. Static and dynamic kinematics were comparable in all but one case, where internal/external tibial rotation differed

Brand placement and consumer choice: an in-store experiment

An in-store experiment was performed to investigate the effects of shelf placement (high, middle, low) on consumers' purchases of potato chips. Placement of potato chips on the middle shelf was associated with the highest percentage of purchases. The results confirm the importance of item placement as a factor in consumers' buying behavior

In-store experimental approach to pricing and consumer behavior

This study assessed how, and to what extent, it is possible to use behavioral experimentation and relative sales analysis to study the effects of price on consumers' brand choices in the store environment. An in-store experiment was performed in four stores to investigate the effects of different prices of a target brand on consumers' relative buying behavior using an alternating treatment design with baseline. The intervention consisted of periodically reducing the target brand's price by 17–26%. Price reductions generally had none or minor effects. However, data for one store showed lower relative sales for the price reduction condition. These are surprising results and they underline the need to examine all of the marketing mix factors, not only price