2 results for Ahmad, Adnan, Doctoral

  • A model of distributed rights allocation in online social interaction : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Information Technology at Massey University, Albany, Auckland, New Zealand

    Ahmad, Adnan (2013)

    Doctoral thesis
    Massey University

    In computing, the management of information resources is done through access control, a process by which authorized users are granted permission over resources. The last decade has witnessed the emergence of socio-technical systems (STS) like Facebook, Twitter, and YouTube, where millions of users interact with each other and share billions of resources on daily basis. Access control for a STS is different from traditional systems in having to satisfy the social requirements of the community as well as the technical requirements of the system. The problems traditional access control models face today are firstly the complexity of mapping millions of users to billions of resources, and secondly the social requirements of users who want to own the resources they post. Current access control models for STS manage access through rule semantics, roles, trust, history management or contents. However, there is no general logical scheme that allows users to allocate rights, covering not just transfer and delegation but also joint and several ownership. The trend from centralized to distributed access control demands a general model to manage rights allocation for users having heterogeneous privacy policies. The model's validity derives from socio-technical design, where social requirements like ownership, freedom and privacy give technical access axioms. The aim is to satisfy not only technical but also social requirements, over which the success of today?s software depends. This research first proposes the social access control model for supporting local administration, dynamic asymmetric relationships and object privacy classification. This core model is then used as a basis of various rights allocation models. The research further illustrates a rights allocation framework based on various properties of STS and presents a reduction approach to design the model. This framework reduces all the possible rights allocations into four basic models: Replace, Revoke, Share and Merge, which can manage every tweet, every post, and every single communication on any STS. The proposed rights allocation models are demonstrated on various current and hypothetical use-cases of current STS to show that it can be used in any system that has social interactions, and where users want to control their resources. This research extends the online social interactions in STS to new horizons which are currently restricted due to the limitations posed by current technology.

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  • Investor protection, firm fundamentals information, and stock price synchronicity : a thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Accounting at Massey University, Albany, New Zealand

    Ahmad, Adnan (2013)

    Doctoral thesis
    Massey University

    This thesis entails a cross-country study on the use of firm fundamentals information (FFI) in capital market pricing decisions and the role investor protection (IP) institutional arrangements play in enhancing the use of FFI in capital markets. I first examine the association between IP and SPS across the 40 countries of Morck Yeung and Yu (MYY) (2000) from 1995 to 2010. This is followed by a study of the association between FFI and SPS and the complementing effects of IP on this association. MYY study the use of FFI by the capital market in making investment decisions. They use stock price synchronicity (SPS) measures as indicators of the use of FFI by the market. SPS is the tendency of share prices to move in the same direction in a given period of time. They posit that when the information environment in a capital market is more developed, investors would use FFI of firms in making investment decisions and this would lower SPS. Conversely, when the information environment in a capital market is less developed, investors would rely on market information in making investment decisions and this would increase SPS. To test the use of FFI they examine the association between SPS and country development (CD), IP, and FFI variables. They do not find any conclusive evidence of the direct association between FFI and SPS, but find that CD and IP are negatively associated with SPS. They also find that CD and IP are both proxies of the general quality of the information environment, with IP being the more effective of the two. Therefore, they conclude that better IP improves the information environment and hence lowers SPS.

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