The problems and challenges of managing crowd sourced audio-visual evidence

A number of recent incidents, such as the Stanley Cup Riots, the uprisings in the Middle East and the London riots have demonstrated the value of crowd sourced audio-visual evidence wherein citizens submit audio-visual footage captured on mobile phones and other devices to aid governmental institutions, responder agencies and law enforcement authorities to confirm the authenticity of incidents and, in the case of criminal activity, to identify perpetrators. The use of such evidence can present a significant logistical challenge to investigators, particularly because of the potential size of data gathered through such mechanisms and the added problems of time-lining disparate sources of evidence and, subsequently, investigating the incident(s). In this paper we explore this problem and, in particular, outline the pressure points for an investigator. We identify and explore a number of particular problems related to the secure receipt of the evidence, imaging, tagging and then time-lining the evidence, and the problem of identifying duplicate and near duplicate items of audio-visual evidence

Auditor attributes and their association with audit fees in Australia: an empirical study

This study investigates the existence of cartel pricing and anticompetitive behavior by the Big4 international providers of auditing services (resulting from the halving in the number of such providers from the Big8 to Big4). Increased audit market concentration, both globally and in Australia, together with the focus by the Big4 in servicing primarily large clients, raises concern about a lessening of competition in the audit marketplace. Using both a composite and dis-aggregated measure for auditor attributes (namely, auditor reputation, industry specialization, provision of non-audit services and auditor tenure), this study provides a comprehensive analysis of the association between four pivotal auditor attributes and the quantum of audit fees and changes in audit fees paid by Australian publicly listed firms during a five-year time frame.The final usable sample includes 600 firm-year observations as data points for the 2001, 2003 and 2005 calendar years (200 firm-years for each year in the aforementioned observation window) and is obtained entirely from publicly available sources, specifically annual reports. Main results from both cross-sectional and longitudinal multivariate analysis indicate that there is no significant association between the four auditor attributes utilized in this study with both audit fees and variation in audit fees. Robustness and sensitivity testing completed also largely support the non-significance of the association between both constructs. This study, therefore, finds no evidence of cartel pricing and anti-competitive behavior by Big4 auditors resulting from increased audit market concentration. Results from this study have clear implications for regulators, investors, scholars, corporate management/firms and auditors

High speed digital protection of EHV transmission lines using traveling waves

Extra High Voltage (EHV) transmission lines are designed to transfer large amount of power from one location to another. The length exposed to the environment is a major reason for occurrence of faults on the lines. A fault on a high voltage transmission line affects the stability of the overall power system, which sometimes leads to permanent damage of the equipment. Relays are developed and installed to protect the lines. The transmission line protection relays, in the industry, are based on the fundamental frequency components of the voltages and currents. These relays need at least one fundamental frequency cycle for performing the protection operation. Voltage and current traveling waves are generated when a fault occurs on the transmission line. The velocity of propagation of traveling waves is finite and the level of the waves decreases with increase in the distance traveled. Information about the fault can be obtained by analyzing the traveling waves. A few traveling wave techniques, which are based on analog signal processing, to protect transmission lines have been proposed in the past. Two digital techniques, which use traveling waves for protecting EHV transmission lines, are proposed in this thesis. The traveling waves are extracted from the modal voltages and currents at the terminals of the transmission line. The techniques identify and locate the fault by using the information contained in the waves. A power system was modeled in the Electromagnetic Transient Direct Current Analysis (EMTDC) and several cases were created by varying different parameters related to the fault, fault type, fault location, fault resistance and fault inception angle. The techniques were implemented in hardware and their performance was tested on data, generated from the EMTDC simulations. Some cases are discussed in the thesis. The performance of the digital techniques for protecting EHV transmission lines using traveling waves was confirmed to be satisfactory. The proposed techniques provide protection at speed and discriminate well between internal and external faults

CONDOR: A Hybrid IDS to Offer Improved Intrusion Detection

Intrusion Detection Systems are an accepted and very useful option to monitor, and detect malicious activities. However, Intrusion Detection Systems have inherent limitations which lead to false positives and false negatives; we propose that combining signature and anomaly based IDSs should be examined. This paper contrasts signature and anomaly-based IDSs, and critiques some proposals about hybrid IDSs with signature and heuristic capabilities, before considering some of their contributions in order to include them as main features of a new hybrid IDS named CONDOR (COmbined Network intrusion Detection ORientate), which is designed to offer superior pattern analysis and anomaly detection by reducing false positive rates and administrator intervention

Non-Forster distance and orientation dependence of energy transfer and applications of fluorescence resonance energy transfer to polymers and nanoparticles: how accurate is the spectroscopic ruler with 1/r6 rule?

Fluorescence resonance energy transfer (FRET) is a popular tool to study equilibrium and dynamical properties of polymers and biopolymers in condensed phases and is now being widely used in conjunction with single molecule spectroscopy. The rate of FRET is usually assumed to be given by the Forster expression: kF = krad(RF/R)6 where krad is the radiative rate (typically less than 109 s-1) and RF is the well-known Forster radius which is given by the spectral overlap between the fluorescence spectrum of the donor and the absorption spectrum of the acceptor. We first present a critical analysis of the derivation of the above expression and argue why this expression can be of limited validity in many cases. We demonstrate this by explicitly considering a donor-acceptor system, polyfluorene (PF6)-tetraphenylporphyrin (TPP), where their sizes are comparable to the distance separating them. In such cases, one may expect much weaker distance (as 1/R2 or even weaker) dependence. Another limitation is that optically dark states can make significant contribution to the energy transfer rate - these contributions are neglected in the Forster expression. Yet another limitation is that Forster, being based on Fermi Golden Rule, neglects vibrational energy relaxation which can be a serious limitation when the rate is in the few picoseconds regime. We have also considered the case of energy transfer from a dye to a nanoparticle. Here we show that the distance dependence can be completely different from Forster and can give rise to 1/R4 distance dependence at large separations. We also discuss recent applications of FRET to study biopolymer conformational dynamics and an interesting breakdown of the famous Wilemski-Fixman theory