Insectivore life histories: further evidence against an optimum body size for mammals

1. This study tests a model of the relationship of body mass to reproductive power (the rate of conversion of energy from the environment to an organism’s offspring). Specifically tested is the prediction that the regression of life-history variables on body size will change slope and sign about an ‘optimum’ body mass of 100 g.
2. Life-history data from the mammalian order Insectivora have been collated and analysed using a phylogenetic comparative method to test this prediction.
3. The analyses showed little evidence for significant changes in slope or sign around 100 g body mass, or other possible optimal body masses, contradicting the predictions of the model. These findings agree with those of similar analyses on life-history variables of bats.

The relationship between emergence of the shortest path and information value using ant-like agents

Ant-like agents forage between two points. These agents' probabilistic movements are based on the use of two pheromones; one marking trails towards the goal and another marking trails back to the starting point. Path selection decisions are influenced by the relative levels of attractive and repulsive pheromone in each agent's local environment. Our work in [5] evaluates three pheromone perception strategies, investigating path formation speed, quality, directionality, robustness and adaptability under different parameter settings(degree of randomness, pheromone evaporation rate and pheromone diffusion rate). We re-evaluate two of these strategies in terms of the amount of information they provide using Shannon's formulation [3, 4, 8, 9, 12, 14, 15, 16, 17]. We determine information as the difference between uncertainty before and after path selection decisions. Our focus in this paper is on investigating relationships between the emergence of the shortest path and the amount of stigmergic information that exists in the form of pheromone. Agents are deployed centrally and emergence measures are determined using the worst, reference and best cases observed in [5]. Additionally, the amount of local and global information that is available to agents in each movement step is evaluated. Furthermore, Pearson's correlation coefficients between measures of emergence and the amount of information are calculated. The significance of these correlation coefficients is tested using a 2 tailed test at 1% level of significance. Consequently the relationship between the amount of information and emergent behaviour is established. Significant relationships between information and the emergence of the shortest path exist when strong emergent behaviour is present.

A probabilistic movement model for shortest path formation in virtual ant-like agents

We propose a probabilistic movement model for controlling ant-like agents foraging between two points. Such agents are all identical, simple, autonomous and can only communicate indirectly through the environment. These agents secrete two types of pheromone, one to mark trails towards the goal and another to mark trails back to the starting point. Three pheromone perception strategies are proposed (Strategy A, B and C). Agents that use strategy A perceive the desirability of a neighbouring location as the difference between levels of attractive and repulsive pheromone in that location. With strategy B, agents perceive the desirability of a location as the quotient of levels of attractive and repulsive pheromone. Agents using strategy C determine the product of the levels of attractive pheromone with the complement of levels of repulsive pheromone. We conduct experiments to confirm directionality as emergent property of trails formed by agents that use each strategy. In addition, we compare path formation speed and the quality of the formed path under changes in the environment. We also investigate each strategy's robustness in environments that contain obstacles. Finally, we investigate how adaptive each strategy is when obstacles are eventually removed from the scene and find that the best strategy of these three is strategy A. Such a strategy provides useful guidelines to researchers in further applications of swarm intelligence metaphors for complex problem solving.

Spatial ecology of sooty owls in south-eastern Australian coastal forests : implications for forest management and reserve design

We investigated the home-range size and habitat use of eight Sooty Owls (Tyto tenebricosa tenebricosa) in coastal forests in East Gippsland, Victoria, Australia, between November 2006 and January 2008. The size of home-ranges varied widely; based on 95% adaptive kernel estimates, the average size of home-ranges of males was 3025ha (±1194s.d., n=3), whereas that of females was 994ha (±654s.d., n=5). Sooty Owls utilised a broad range of ecological vegetation classes and topographical features for roosting and foraging at a greater scale than previously assumed. There was minimal selection for habitat types based on floristic composition, primarily only avoiding heathlands (for foraging and roosting) and selecting particular dense foliage (rainforest and riparian scrub) for foliage roosting. Two Owls maintained home-ranges close to logged areas, with logging regrowth (<45 years old) being strongly avoided by both individuals. We recommend that the size of individual reserves for Sooty Owls in commercial forests should be increased to more closely resemble the core spatial resource requirements needed by a pair. Reserves should be largest where they feed predominantly on hollow-dependent prey. Most importantly, rather than conservation measures just focussing on the spatial requirements of Sooty Owls, efforts should be directed towards retaining high densities of crucial resources, such as hollow-bearing trees and mammalian prey species throughout the landscape.

Policy trajectories : treading the discursive path of policy analysis

This paper is concerned with theorising the nature of policy and its production. It takes as its starting point the work of Stephen Ball,1 particularly his writings within the pages of this journal (13(2), 1993)—later reprinted as Chapter 2 in Education Reform (1994a)—as well as his earlier writings in Politics and Policy Making in Education (1990) and Reforming Education and Changing Schools (Bowe, Ball & Gold, 1992). More broadly, the paper is located within a 'new' sociological interest in education policy often referred to as 'policy sociology'2 (Payne, Dingwall, Payne & Carter, 1981; Ozga, 1987, Ball, 1990; Bowe, Ball & Gold, 1992); a concern that is 'rooted in the social science tradition, historically informed and drawing on qualitative and illuminative techniques' (Ozga, 1987, p. 144) and 'united by the conviction that "things", especially policy discourse, must be pulled apart' (Troyna, 1994, p. 71) to determine whose interests they serve.

An adjustable force field for multiple robot mission and path planning

Mission and path planning for multiple robots in dynamic environments is required when multiple mobile robots or unmanned vehicles are used for geographically distributed tasks. Assigning tasks and paths for robots for cooperatively accomplishing a mission of reaching to number of target points are addressed in this paper. The methodology that is proposed is based on using an adjustable force field which is suitable for dynamic environment. From the force field analysis, the decisions to assign tasks for each robot are then made. The force field is also used to plan a collision free path for each robot. Adjustable weights for the force field model are proposed to satisfy the constraints of the motion. In this research, the constraints are the cooperation of the robots, the precedence between the targets and between robots, and the discrimination between different obstacles. Two simulations for mission and path planning in 2D and 3D dynamic spaces with multiple robots are presented based on the proposed adjustable force filed. The result of the mission and path planning for three robots cooperatively doing eight target points are shown.

AdaBoost.MRF: boosted Markov random forests and application to multilevel activity recognition

Activity recognition is an important issue in building intelligent monitoring systems. We address the recognition of multilevel activities in this paper via a conditional Markov random field (MRF), known as the dynamic conditional random field (DCRF). Parameter estimation in general MRFs using maximum likelihood is known to be computationally challenging (except for extreme cases), and thus we propose an efficient boosting-based algorithm AdaBoost.MRF for this task. Distinct from most existing work, our algorithm can handle hidden variables (missing labels) and is particularly attractive for smarthouse domains where reliable labels are often sparsely observed. Furthermore, our method works exclusively on trees and thus is guaranteed to converge. We apply the AdaBoost.MRF algorithm to a home video surveillance application and demonstrate its efficacy.

Exploiting monge structures in optimum subwindow search

Optimum subwindow search for object detection aims to find a subwindow so that the contained subimage is most similar to the query object. This problem can be formulated as a four dimensional (4D) maximum entry search problem wherein each entry corresponds to the quality score of the subimage contained in a subwindow. For n x n images, a naive exhaustive search requires O(n⁴) sequential computations of the quality scores for all subwindows. To reduce the time complexity, we prove that, for some typical similarity functions like Euclidian metric, χ² metric on image histograms, the associated 4D array carries some Monge structures and we utilise these properties to speed up the optimum subwindow search and the time complexity is reduced to O(n³). Furthermore, we propose a locally optimal alternating column and row search method with typical quadratic time complexity O(n²). Experiments on PASCAL VOC 2006 demonstrate that the alternating method is significantly faster than the well known efficient subwindow search (ESS) method whilst the performance loss due to local maxima problem is negligible.

The path to Project Darwin : the evolution of the AMP's organisational structure

Demutualisation became a global trend amongst financial sector firms in the last two decades of the twentieth century. Changes to the organisational foundations of mutual firms represented a shift in operational cultures and have often been viewed as an end point or demise of the co-operative business model. It is the intention of this article to investigate the extent to which this was the case within a major mutual institution, the Australian Mutual Provident, Australia's oldest and largest mutual insurer. The article's key argument is that the concept of mutuality is organic, and that within this organisation it evolved as the structure of the firm became more sophisticated as it developed from a supplier of life insurance products into a sophisticated financial services provider, which ultimately generated internal pressures to demutualise.

Two steps forward, one step back : Indonesia’s arduous path to reform

Australians have long worried about whether Indonesia is ‘special’ or ‘normal’. Instead, we need to deal with Indonesia as it really is—a country experiencing simultaneously the challenges of political reform, economic development and a shifting regional security environment. The country’s political future is less certain than we would hope: after SBY’s term of government ends, the choice of a successor will be critical in determining the future of reform. We can’t rule out that Indonesia might slide back to old ways of doing business—democratisation is a fraught process.
As the Indonesian economy grows, so too do the prospects for Indonesia to establish its natural position as the leader of Southeast Asia. As the world is re-examining Indonesia, so too Indonesia is looking afresh at the world—more interested in external issues than it was a decade ago. The Southeast Asian subregion increasingly finds itself at the centre of a more strongly interconnected Indo-Pacific region—so Indonesia’s strategic importance is going up.
It’s important for Australia to build a better strategic relationship with Indonesia. The two are complementary partners. Australia should be proactive in exploring new opportunities for cooperation with a reform minded Indonesia—it’s in our interests to draw Indonesia into a more important strategic role in regional security.
Professor Damien Kingsbury, the author of this Strategy, is the Director, Centre for Citizenship, Development and Human Rights, Faculty of Arts and Education, Deakin University, Melbourne.