Includes bibliographical references (p. 250-262).

Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xi, 124 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 118-124).

This work studies the consequences of a human-initiated targeted attack on the electric power system by simulating the detonation of a bomb at one or more substations in and around Washington DC. An AC power flow based transient analysis on a realistic power grid model of Eastern Interconnection is considered to study the cascading events. A detailed model of control and protection system in the power grid is considered to ensure the accurate representation of cascading outages. Particularly, the problem of identifying a set of k critical nodes, whose failure/attack leads to the maximum adverse impact on the power system has been analyzed in detail. It is observed that a greedy approach yields node sets with higher criticality than a degree-based approach, which has been suggested in many prior works. Furthermore, it is seen that the impact of a targeted attack exhibits a nonmonotonic behavior as a function of the target set size k. The consideration of hidden failures in the protective relays has revealed that the outage of certain lines/buses in the course of cascading events can save the power grid from a system collapse. Finally, a comparison with the DC steady state analysis of cascading events shows that a transient stability assessment is necessary to obtain the complete picture of cascading events in the aftermath of a targeted attack on the power grid. / M.S. / The modern day power system has been identified as a critical infrastructure providing crucial support to the economy of a country. Prior experience has shown that a small failure of a component in the power grid can lead to widespread cascading events and eventually result in a blackout. Such failures can be triggered by devastating damage due to a natural calamity or because of a targeted adversarial attack on certain points in the power system. Given limited budget to avoid widespread cascading failures in the network, an important problem would be to identify critical components in the power system. In this research an attempt has been made to replicate the actual power system conditions as accurately as possible to study the impact of a targeted adversarial attack on different points in the network. Three heuristics have been proposed to identify critical nodes in the network and their performance has been discussed. The case studies of cascading events have been performed on a synthetic power system network of Washington DC to achieve the actual system conditions of an operating power grid.

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University of Macau / Faculty of Science and Technology. / Department of Electromechanical Engineering

Thesis (Ph. D.)--University of Texas at Austin, 2003. / Supervisor: Eric B. Williamson. Vita. Includes bibliographical references. Also available from UMI.

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This thesis is an attempt to trace the aspects of civil protection of company property from the conduct of directors in insolvent liquidation in Scotland. It emphasises the origin of the problem and the essential need to protect company property, particularly in public limited companies. This protection is required for two reasons. First, directors may abuse their powers and take advantage of the privilege of limited liability they enjoy. Second, the separation between ownership and control. There are several aspects of civil protection which are provided by the Insolvency Act 1986, the Company Directors Disqualification Act 1986 and the common law. Regarding civil protection after the commencement of an insolvent liquidation, the Insolvency Act protects company property: (1) by terminating all of the directors' powers in a creditors voluntary liquidation (s.103); (2) by avoiding dispositions of company property after the commencement of liquidation in a compulsory liquidation (s.127); (3) by making public and private examinations to investigate directors' conduct in their dealings with the company (ss. 133, 236 and 112); (4) by prohibiting directors from re-using the company's name (ss. 216-217) and (5) by disqualifying directors who are ordered by the court to contribute to the company's assets as a result of fraudulent and wrongful trading (s. 10 of the C.D.D.A. 1986) and those directors whose conduct makes them unfit to be concerned in the management of the company (s. 6 of the C.D.D.A. 1986). But to maximise this protection a provision should be added to provide that directors' powers should cease in a compulsory liquidation not only after the liquidation order but also after the appointment of a provisional liquidator except with the leave of the court. Section 127 should also extend to cover any disposition made after the making of a resolution to wind up the company voluntarily and before the appointment of the liquidator and after his appointment.