Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: Lizy K. John. Vita. Includes bibliographical references. Also available from UMI.

Approved for public release, distribution is unlimited / The subversion technique of attacking an operating system is often overlooked in information security. Operating Systems are vulnerable throughout their lifecycle in that small artifices can be inserted into an operating system's code that, on command, can completely disable its security mechanisms. To illustrate that this threat is viable, it is shown that it is not difficult for an attacker to implement the framework for the "two-card loader" type of subversion, a trap door which enables the insertion of arbitrary code into the operating system while the system is deployed and running. This framework provides several services such as memory allocation in the attacked system, and mechanisms for relocating, linking and loading the inserted attack code. Additionally, this thesis shows how Windows XP embedded designers can use Intel's x86 hardware more effectively to build a higher assurance operating system. Principles of hardware support are discussed and recommendations are presented. Subversion is overlooked because critics believe the attack is too difficult to carry out. It is illustrated in this thesis that this is simply not the case. Anyone with access to the operating system code at some point in its lifecycle can design a fairly elaborate subversion artifice with modest effort. / Ensign, United States Navy Reserve

This thesis proposes a new dynamic resource management architecture, Magnet, to meet the requirements of users in flexible and adaptive systems. Computer systems no longer operate in centralized isolated static environments. Technological advances, such as smaller and faster hardware, and higher reliability of networks have resulted in the growth of mobility of computing and the need for run-time reconfigurability. The dynamic management of this diversity of resources is the central issue addressed in this thesis. Applications in environments with frequently changing characteristics are required to participate in dynamic resource management, to adapt to ever-changing conditions, and to express their requirements in terms of quality of service. Magnet enables dynamic trading of resources which can be requested indirectly by the type of service they offer, rather than directly by their name. A dedicated component, the Trader, matches requests for services against demands and establishes a component binding - resource allocation. In addition, the architecture is extensible - it does not constrain the information on services and allows user-customization of the matching process. Consequently, this allows resource definitions to be parametrized (to include QoS-based characteristics), and the matching process to be user-customized (to preform QoS-based negotiation). In order to fulfill the requirements of users relying on ever-changing conditions, Magnet enables runtime adaptation (dynamic rebinding) to changes in the environment, constant monitoring of resources, and scalability of the architecture. The generality of the Magnet architecture is illustrated with several examples of resource allocation in dynamic environments.

by Ma Hon-chung. / Bibliography: leaves [199]-[204] / Thesis (M.Ph.)--Chinese University of Hong Kong, 1984

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Disk space fragmentation is the proliferation of small and unusable gaps. This problem is considered within the context of IBM's VM operating system. Facing this problem, researchers resorted to using algorithms based on memory management techniques, such as placement strategies (first-fit, best-fit, and worst-fit). Solutions based on these algorithms do not yield optimum results. Furthermore, in many cases, their efficiency and cost effectiveness are questionable. This work proposes a new method to address the disk fragmentation problem using improved I/0 techniques. Optimum results and efficiency are some of the qualities that contribute to the superiority of this approach. The algorithm was implemented and test figures were compared with calculated figures. The results clearly favor this new algorithm. / Graduation date: 1991

Thesis (M.S. in Computer Science)--Naval Postgraduate School, June 2003. / Thesis advisor(s): Cynthia E. Irvine, Roger R. Schell. Includes bibliographical references (p. 83-92). Also available online.

Thesis (M.S. in Computer Science)--Naval Postgraduate School, June 2003. / Thesis advisor(s): Cynthia E. Irvine, Roger R. Schell. Includes bibliographical references (p. 105-107). Also available online.

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