The prevalence of melanoma skin cancer disease is rapidly increasing as recorded death cases of its patients continue to annually escalate. Reliable segmentation of skin lesion is one essential requirement of an efficient noninvasive computer aided diagnosis tool for accelerating the identification process of melanoma. This paper presents a new algorithm based on perceptual color difference saliency along with binary morphological analysis for segmentation of melanoma skin lesion in dermoscopic images. The new algorithm is compared with existing image segmentation algorithms on benchmark dermoscopic images acquired from public corpora. Results of both qualitative and quantitative evaluations of the new algorithm are encouraging as the algorithm performs excellently in comparison with the existing image segmentation algorithms.

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This paper proposes an alternative to the office metaphor for African users unfamiliar with the office environment. The objective of the research was to identify users for whom the African Village metaphor is better than the office metaphor. Five widely used African cultural objects were identified for the design of user interface icons for the African Village metaphor. Computer Science and Information Technology staff members from four universities in the KwaZulu-Natal province of South Africa completed a questionnaire. The questionnaire requested participants to identify icons from the current office metaphor, identify the five African objects, to indicate their traditional use, associate these objects with computer actions, and indicate their level of support for the African Village metaphor. Participants were grouped according to age and culture. The data were analysed using proportions, means and correlation analysis. Results indicate that in all age groups a larger proportion of African users support the African Village metaphor compared to users from other cultural groups, and that support is almost null among young users from other cultural groups. On the ability to associate African objects with computer actions, older African users performed better than younger Africans, but younger users from other cultural groups performed better than their peers. On the knowledge of African cultural objects, young African participants performed worse compared to young participants from other cultures. A significant correlation was found between knowledge of cultural objects and ability to associate computer actions with cultural objects. The research results show the African Village metaphor is more suitable for older African users than the office metaphor. The paper assesses the effectiveness of a possible alternative to the office metaphor, capable of improving usability especially for African users and contribute towards improving computer literacy for this group of users.

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This thesis reports on original exploratory study that is aimed at contributing towards understanding of factors that influence Africa users support for alternative object metaphors for user interface icons. One of the great impediments for efficient utilization of information systems is the existing gap between system designs that typically follow western cues for crafting user interfaces and actual users who use those systems within their diverse cultural frames. The problem remains important because of the wider penetration of information systems, which serve as modern technology tools to improve service provisioning worldwide. In order to overcome the problem of optimum utilization of information systems, previous studies have proposed culturally adaptive user interfaces. The basic principle behind culture adaptive interfaces is to develop intelligent user interfaces that can automatically adapt to user contexts. However, the challenges with the new proposals for adaptive user interfaces are how to best model information about users, how to access the cultural background of individual users and empirically examine the effects of culture on user interface preferences. In order to properly contribute to solving these problems, an exploratory study was conducted to empirically establish African rural users support for alternative village object metaphors, examine effects of culture on user support and investigate response characteristic among culturally diverse user groups. The synthesis of bodystorming and cultural probes methodology was applied to engage the participation of African rural users in the study. Technology support model was developed to measure user knowledge, comprehension, skills, performance and support for alternative African village metaphors as interface icons. The partial least square analytic modelling technique and finite mixture path segmentation model were used to test a set of research hypotheses and detect heterogeneity in 71 respondent data generated. Experimental results of this study show that human cognitive factors of technology knowledge, comprehension and performance influence African users support for alternative village object metaphors as interface icons. However, skill factor is not found to influence user support for alternative African village object metaphors. The factor of culture is found to moderate the effects of comprehension on user support and effects of user performance on user support. This study also identifies three segments of African users that result in heterogeneity within the inner path model.

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