Intelligent line segment perception with cortex-like mechanisms

This paper proposes a novel general framework for line segment perception, which is motivated by a biological visual cortex, and requires no parameter tuning. In this framework, we design a model to approximate receptive fields of simple cells. More importantly, the structure of biological orientation columns is imitated by organizing artificial complex and hypercomplex cells with the same orientation into independent arrays. Besides, an interaction mechanism is implemented by a set of self-organization rules. Enlightened by the visual topological theory, the outputs of these artificial cells are integrated to generate line segments that can describe nonlocal structural information of images. Each line segment is evaluated quantitatively by its significance. The computation complexity is also analyzed. The proposed method is tested and compared to state-of-the-art algorithms on real images with complex scenes and strong noises. The experiments demonstrate that our method outperforms the existing methods in the balance between conciseness and completeness.

Segment reporting and corporate takeovers : user needs

The nature of a corporate takeover often leads to the contraction in the number of companies operating in a given industry classification, along with the contraction in the amount of formal financial statements produced by the companies in that industry. Since 1985 Australian diversified companies are required to break their operations down into industry and geographical segments, so it would be expected that companies which diversify their operations through a corporate takeover would be forerunners in the adoption of this relatively new accounting standard on segment reporting. While previous studies have both declared the benefits of segment reporting to report users, and exposed some preconceived problems of its application in practice, there has not been any work on the 'usefulness1 of segment reporting as a form of reporting that will compensate shareholder users for the information loss suffered during a corporate takeover. This study endeavours to determine this, by questioning shareholders of companies that have been involved in takeovers in a period subsequent to the application date of the segment reporting standard, and obtaining their views on the usefulness of the post-takeover segment reports produced by their companies. A link is discovered to exist between shareholder dissatisfaction with segment reporting and the non-practice of creating a new segment in the post-takeover annual report for the target acquired. The underlying assumption that the practice of new segment creation after a takeover is influenced by the type of takeover undertaken is supported by the study. Regardless of whether or not a company is diversified before the takeover, the findings show that a corporate acquirer in a takeover is less likely to create a new industry or geographical segment for the target acquired if they are involved in horizontal or vertical takeovers than if they are involved in diversified takeovers. In these situations, segment reporting is found to not compensate shareholders for the loss of information incurred by them in these types of takeovers.

Development and application of a microelectrode based scanning voltammetric detector

A large part of the work presented in this thesis describes the development and use of a novel electrochemical detector designed to allow the electrochemical characterisation of compounds in flowing solution by means of cyclic voltammetry. The detector was microprocessor controlled, which provides digital generation of the potential waveform and collection of data for subsequent analysis. Microdisk working electrodes are employed to permit both thermodynamic and kinetically controlled processes to be studied under steady-state conditions in flowing solutions without the distortion or hysteresis normally encountered with larger sized electrodes. The effect of electrode size, potential scan rate, and solution flow rate are studied extensively with the oxidation of ferrocene used as an example of a thermodynamically controlled process and a series of catecholamines as examples of a kinetically controlled process. The performance of the detector was best demonstrated when used as a HPLC post-column detector. The 3-dimensional chromatovoltammograms obtained allow on-line characterisation of each fraction as it elutes from the column. The rest of the work presented in this thesis involves the study of the oxidative degradation pathway of dithranol. The oxidative pathway was shown to involve a complex free radical mechanism, dependent on the presence of both oxygen and, in particular light. The pathway is further complicated by the fact that dithranol may exist in either a keto or enol form, the enol being most susceptible to oxidation. A likely mechanism is proposed from studies performed with cyclic voltammetry and controlled potential electrolysis, then defined by subsequent kinetic studies.