Towards improving mission execution for autonomous gliders with an ocean model and Kalman filter

In this paper, we examine the use of a Kalman filter to aid in the mission planning process for autonomous gliders. Given a set of waypoints defining the planned mission and a prediction of the ocean currents from a regional ocean model, we present an approach to determine the best, constant, time interval at which the glider should surface to maintain a prescribed tracking error, and minimizing time on the ocean surface. We assume basic parameters for the execution of a given mission, and provide the results of the Kalman filter mission planning approach. These results are compared with previous executions of the given mission scenario.

The effect of emotional and attentional load on attentional startle modulation

The interactive effects of emotion and attention on attentional startle modulation were investigated in two experiments. Participants performed a discrimination and counting task with two visual stimuli during which acoustic eyeblink startle-eliciting probes were presented at long lead intervals. In Experiment 1, this task was combined with aversive Pavlovian conditioning. In Group Attend CS+, the attended stimulus was followed by an aversive unconditional stimulus (US) and the ignored stimulus was presented alone whereas the ignored stimulus was paired with the US in Group Attend CS−. In Experiment 2, a non-aversive reaction time task US replaced the aversive US. Regardless of the conditioning manipulation and consistent with a modality non-specific account of attentional startle modulation, startle magnitude was larger during attended than ignored stimuli in both experiments. Blink latency shortening was differentially affected by the conditioning manipulations suggesting additive effects of conditioning and discrimination and counting task on blink startle.

The relationship between self-reported animal fear and ERP modulation : Evidence for enhanced processing and fear of harmless invertebrates in snake- and spider-fearful individuals

The present study used ERPs to compare processing of fear-relevant (FR) animals (snakes and spiders) and non-fear-relevant (NFR) animals similar in appearance (worms and beetles). EEG was recorded from 18 undergraduate participants (10 females) as they completed two animal-viewing tasks that required simple categorization decisions. Participants were divided on a post hoc basis into low snake/spider fear and high snake/spider fear groups. Overall, FR animals were rated higher on fear and elicited a larger LPC. However, individual differences qualified these effects. Participants in the low fear group showed clear differentiation between FR and NFR animals on subjective ratings of fear and LPC modulation. In contrast, participants in the high fear group did not show such differentiation between FR and NFR animals. These findings suggest that the salience of feared-FR animals may generalize on both a behavioural and electro-cortical level to other animals of similar appearance but of a non-harmful nature.

The Galapagos Islands and Darwin's (en)tangled bank

The body of the article concerns itself with the vulnerability of islands and focuses on the Galapagos Archipelago where the author spent three years studying flamingoes and flightless cormorants.The article suggests practical, simple behavioural changes that individuals might adopt to help increase biodiversity and extend natural corridors and islands of vegetation throughout cities and suburbs. It will ask some questions about human motives for behaviour change and moral decisions.

Intensity dependent residual amplitude modulation in electro-optic phase modulators

Residual amplitude modulation (RAM) mechanisms in electro-optic phase modulators are detrimental in applications that require high purity phase modulation of the incident laser beam. While the origins of RAMare not fully understood, measurements have revealed that it depends on the beam properties of the laser as well as the properties of the medium. Here we present experimental and theoretical results that demonstrate, for the first time, the dependence of RAM production in electro-optic phase modulators on beam intensity. The results show an order of magnitude increase in the level of RAM, around 10 dB, with a fifteenfold enhancement in the input intensity from 12 to 190 mW/mm 2. We show that this intensity dependent RAM is photorefractive in origin. © 2012 Optical Society of America.

Polarization dependent photorefractive amplitude modulation production in MgO:LiNbO 3 phase modulators

We present experimental and theoretical results of the intensity dependence of residual amplitude modulation (RAM) production in electro-optic phase modulators. By utilizing the anisotropy of the medium, we show that RAM has a photorefractive origin.

Fast power line detection and localization using steerable filter for active UAV guidance

In this paper we present a fast power line detection and localisation algorithm as well as propose a high-level guidance architecture for active vision-based Unmanned Aerial Vehicle (UAV) guidance. The detection stage is based on steerable filters for edge ridge detection, followed by a line fitting algorithm to refine candidate power lines in images. The guidance architecture assumes an UAV with an onboard Gimbal camera. We first control the position of the Gimbal such that the power line is in the field of view of the camera. Then its pose is used to generate the appropriate control commands such that the aircraft moves and flies above the lines. We present initial experimental results for the detection stage which shows that the proposed algorithm outperforms two state-of-the-art line detection algorithms for power line detection from aerial imagery.

In the bank or on the ground : an examination of financial reserves in Australian international aid organisations

This study contributes to the understanding of the contribution of financial reserves to sustaining nonprofit organisations. Recognising the limited recent Australian research in the area of nonprofit financial vulnerability, it specifically examines financial reserves held by signatories to the Code of Conduct of the Australian Council for International Development (ACFID) for the years 2006 to 2010. As this period includes the Global Financial Crisis, it presents a unique opportunity to observe the role of savings in a period of heightened financial threats to sustainability. The need for nonprofit entities to maintain reserves, while appearing intuitively evident, is neither unanimously accepted nor supported by established theoretic constructs. Some early frameworks attempt to explain the savings behaviour of nonprofit organisations and its role in organisational sustainability. Where researchers have considered the issue, its treatment has usually been either purely descriptive or alternatively, peripheral to a broader attempt to predict financial vulnerability. Given the importance of nonprofit entities to civil society, the sustainability of these organisations during times of economic contraction, such as the recent Global Financial Crisis, is a significant issue. Widespread failure of nonprofits, or even the perception of failure, will directly affect, not only those individuals who access their public goods and services, but would also have impacts on public confidence in both government and the sectors’ ability to manage and achieve their purpose. This study attempts to ‘shine a light’ on the paradox inherent in considering nonprofit savings. On the one hand, a public prevailing view is that nonprofit organisations should not hoard and indeed, should spend all of their funds on the direct achievement of their purposes. Against this, is the commonsense need for a financial buffer if only to allow for the day to day contingencies of pay rises and cost increases. At the entity level, the extent of reserves accumulated (or not) is an important consideration for Management Boards. The general public are also interested in knowing the level of funds held by nonprofits as a measure of both their commitment to purpose and as an indicator of their effectiveness. There is a need to communicate the level and prevalence of reserve holdings, balancing the prudent hedging of uncertainty against a sense of resource hoarding in the mind of donors. Finally, funders (especially governments) are interested in knowing the appropriate level of reserves to facilitate the ongoing sustainability of the sector. This is particularly so where organisations are involved in the provision of essential public goods and services. At a scholarly level, the study seeks to provide a rationale for this behaviour within the context of appropriate theory. At a practical level, the study seeks to give an indication of the drivers for savings, the actual levels of reserves held within the sector studied, as well as an indication as to whether the presence of reserves did mitigate the effects of financial turmoil during the Global Financial Crisis. The argument is not whether there is a need to ensure sustainability of nonprofits, but rather how it is to be done and whether the holding of reserves (net assets) is an essential element is achieving this. While the study offers no simple answers, it does appear that the organisations studied present as two groups, the ‘savers’ who build reserves and keep ‘money in the bank’ and ‘spender-delivers’ who put their resources ‘on the ground’. To progress an understanding of this dichotomy, the study suggests a need to move from its current approach to one which needs to more closely explore accounts based empirical donor attitude and nonprofit Management Board strategy.

Mesopic rod and S-cone interactions revealed by modulation thresholds

We analyzed mesopic rod and S-cone interactions in terms of their contributions to the blue-yellow opponent pathway. Stimuli were generated using a 4-primary colorimeter. Mixed rod and S-cone modulation thresholds (constant L-, M-cone excitation) were measured as a function of their phase difference. Modulation amplitude was equated using threshold units and contrast ratios. This study identified three interaction types: (1) A linear and antagonistic rod:S-cone interaction, (2) probability summation (3) and a previously unidentified mutual nonlinear reinforcement. Linear rod:S-cone interactions occur within the blue-yellow opponent pathway. Probability summation involves signaling by different post-receptoral pathways. The origin of the nonlinear reinforcement is possibly at the photoreceptors.

A yellow filter improves response times to low-contrast targets and traffic hazards

Purpose Anecdotal evidence suggests that some sunglass users prefer yellow tints for outdoor activities, such as driving, and research has suggested that such tints improve the apparent contrast and brightness of real-world objects. The aim of this study was to establish whether yellow filters resulted in objective improvements in performance for visual tasks relevant to driving. Methods Response times of nine young (age [mean ± SD], 31.4 ± 6.7 years) and nine older (age, [mean ± SD], 74.6 ± 4.8) adults were measured using video presentations of traffic hazards (driving hazard perception task) and a simple low-contrast grating appeared at random peripheral locations on a computer screen. Response times were compared when participants wore a yellow filter (with and without a linear polarizer) versus a neutral density filter (with and without a linear polarizer). All lens combinations were matched to have similar luminance transmittances (˜27%). Results In the driving hazard perception task, the young but not the older participants responded significantly more rapidly to hazards when wearing a yellow filter than with a luminance-matched neutral density filter (mean difference, 450 milliseconds). In the low-contrast grating task, younger participants also responded more quickly for the yellow filter condition but only when combined with a polarizer. Although response times increased with increasing stimulus eccentricity for the low-contrast grating task, for the younger participants, this slowing of response times with increased eccentricity was reduced in the presence of a yellow filter, indicating that perception of more peripheral objects may be improved by this filter combination. Conclusions Yellow filters improve response times for younger adults for visual tasks relevant to driving.

Properties of hand-made clay balls used as a novel filter media

Filtration using granular media such as quarried sand, anthracite and granular activated carbon is a well-known technique used in both water and wastewater treatment. A relatively new prefiltration method called pebble matrix filtration (PMF) technology has been proved effective in treating high turbidity water during heavy rain periods that occur in many parts of the world. Sand and pebbles are the principal filter media used in PMF laboratory and pilot field trials conducted in the UK, Papua New Guinea and Serbia. However during first full-scale trials at a water treatment plant in Sri Lanka in 2008, problems were encountered in sourcing the required uniform size and shape of pebbles due to cost, scarcity and Government regulations on pebble dredging. As an alternative to pebbles, hand-made clay pebbles (balls) were fired in a kiln and their performance evaluated for the sustainability of the PMF system. These clay balls within a filter bed are subjected to stresses due to self-weight and overburden, therefore, it is important that clay balls should be able to withstand these stresses in water saturated conditions. In this paper, experimentally determined physical properties including compression failure load (Uniaxial Compressive Strength) and tensile strength at failure (theoretical) of hand-made clay balls are described. Hand-made clay balls fired between the kiln temperatures of 875oC to 960oC gave failure loads of between 3.0 kN and 7.1 kN. In another test when clay balls were fired to 1250oC the failure load was 35.0 kN compared to natural Scottish cobbles with an average failure load of 29.5 kN. The uniaxial compressive strength of clay balls obtained by experiment has been presented in terms of the tensile yield stress of clay balls. Based on the effective stress principle in soil mechanics, a method for the estimation of maximum theoretical load on clay balls used as filter media is proposed and compared with experimental failure loads.

"Food For Thought" Selected Design Installation DIA Homegrown 2011 Life In the Slow Lane Exhibition: Little Stanley Street, South Bank, Brisbane

'Homegrown is an initiative of the Design Institute of Australia–Queensland Branch to promote the collaboration and cultivation of local design talent in Queensland and strengthen the connection between design, plate, planet, people and culture.' Homegrown 2011 Exhibition Catalogue Excerpt

Fiber Bragg grating strain modulation based on nonlinear string transverse force amplifier

The only effective method of Fiber Bragg Grating (FBG) strain modulation has been by changing the distance between its two fixed ends. We demonstrate an alternative being more sensitive to force based on the nonlinear amplification relationship between a transverse force applied to a stretched string and its induced axial force. It may improve the sensitivity and size of an FBG force sensor, reduce the number of FBGs needed for multi-axial force monitoring, and control the resonant frequency of an FBG accelerometer.

Grameen Bank's social performance disclosure : responding to a negative assessment by Wall Street Journal in late 2001

Purpose – The aim of this paper is to establish a linkage between negative global media news towards Grameen Bank (GB), the largest microfinance organisation in the developing world, and the extent and type of annual report social performance disclosures by GB, over the nine-year period 1997-2005. Design/methodology/approach – Content analysis instruments are utilised to analyse GB annual report social disclosure. Findings – The study finds that GB's community poverty alleviation disclosures account for the highest proportion of total social disclosures in the period 1997-2005. The results of this study are particularly significant in relation to poverty alleviation – the issue attracting severe criticism from the Wall Street Journal (WSJ?) late in 2001. The community poverty alleviation disclosures by GB are significantly greater over the four years following the negative news in the WSJ than in the four years before. The results suggest that GB responds to a negative media story or legitimacy threatening news via annual report social disclosures in an attempt to re-establish its legitimacy. Originality/value – This paper contributes to the literature because in the past there has been no research published linking global media attention to the social disclosure practices of major organisations in developing countries