Seeing the soil through the trees: the utility of stem shape and taper in the butt swell for predicting soil depth in Australian Pinus plantations

"Precision forestry" is an emerging concept that is currently shaping the management of commercial forests worldwide. An increasing proportion of the world's wood is grown in plantation forests, so more site-specific or precise management of these forests is important for global wood supply, as well as for the profitability and sustainability of individual plantation estates. Managing plantations at such a fine scale requires a much more detailed understanding of spatial variation in soil resources than has been the case in the past. Current approaches to soil mapping are constrained by the logistic limitations and considerable expense of soil sampling. For this reason, finer-scale soil mapping across the large areas that characterise plantation estates is not feasible. Relationships between soil properties and attributes of tree growth are well established for major plantation species. The relationship between soil properties and stem shape and taper in the base or butt swell section of the tree stem has not previously been established or quantified, but physiological models of stem development suggest an association between this section of the stem and the quantity of soil resources. This thesis investigated the nature and utility of stem shape and taper in the butt swell section for predicting forest soil depth. Fieldwork to address this topic was conducted at a series of case study plantation sites in southern and eastern Australia. A regression model for predicting soil depth from tree shape measurements in the basal 2 m of the stem was developed and improved progressively as data was acquired from each case study site. Stem shape and taper in the butt-swell section of the stem was found to be strongly and predictably related to soil depth across all sample sites, which encompassed a broad range of soil types and depths. At its current stage of development, the model requires calibration for the location at which it is applied from a relatively small number of soil depth measurements. The quality of the map generated by the model was found to be equivalent to that produced using the conventional method of soil mapping; and better than the map generated by a model based on the well-established tree height. The results of this thesis are encouraging for fine-scale soil mapping in plantation forests. They suggest, firstly, that variation in the shape and taper of the butt swell section of the tree stem can be used to predict soil properties - certainly soil depth, and possibly, with further development, other soil properties relevant to tree growth; and secondly, that there is considerable promise for a simple tree-based approach to mapping fine-scale spatial variation in at least soil depth, and perhaps other soil properties. This, in turn, offers the prospect of a feasible and low-cost means of generating the information necessary to support finer-scale plantation management, such as that envisaged by precision forestry. -- provided by Candidate

Development of Roof Insulation Material from Low Density Polyethylene (LDPE), Kapok Fibre and Maerogel

The roof thermal performance exerts a strong influence in controlling the building’s interior temperature. In Malaysia, people are suffering of the hot weather throughout the year especially during daytime. This research aims to develop the most effective roof insulation materials. In order to achieve that, three types of composite roof insulation samples are created through compression molding. Besides, tensile test and thermal conductivity test are conducted. Also, simulation of the thermal performance of the composites are done by using Autodesk Ecotect. All of the composites are found to be effective as they capable to maintain the indoor temperature at lesser than 34°C which is the limit of acceptable thermal comfort temperature limit (Makaremi, Salleh, Jaafar, & GhaffarianHoseini, 2012; Wijewardane & Jayasinghe, 2008)

Two essays on corporate finance

textThis dissertation consists of two essays on corporate finance. Essay one examines whether corporate governance affects firm performance after capital investments. I find that among firms with weak corporate governance, those with high abnormal capital investments have significantly lower stock performance than those with low abnormal capital investments. In addition, a significant portion of the difference in abnormal stock performance between the two subgroups occurs around earnings announcements. In contrast, the level of abnormal capital investments is not related to subsequent stock performance or earnings announcement returns at firms with strong corporate governance. These findings indicate that corporate governance structure enhances firm value by mitigating the over-investment problem. Essay two examines how insider trading activity prior to seasoned equity offerings (SEOs) is related to subsequent investment, operating, and financing decisions of the issuer. I find that SEO firms with more abnormal insider sales issue more seasoned equity, hold more cash and increase dividend payouts more. They also perform more poorly. Following the SEO, these firms also issue less equity and the effects of the SEO on their capital structures gradually reverses. These findings suggest that SEO firms with more abnormal insider sales are more likely to have overpriced stock, while those with less abnormal insider sales are more likely to have good investment opportunities. Insider trading activity prior to the SEO provides valuable information about the firm’s incentives to issue seasoned equity and help to predict the real activities of the issuer following the SEO.Financ

Leading adaptation practices and support strategies for Australia: An international and Australian review of products and tools

The need to address climate change adaptation is growing internationally and not least of all in Australia. There has been a significant investment in adaptation research, risk assessment and planning in Australia, especially since 2007, with substantial support from government funding.  This has led to a strong growth of adaptation knowledge and practical experience, which has confirmed that adaptation planning and decision-making introduce new and complex challenges. These arise from the need to address not only traditional climate variability but also increasing current climate risks, and even greater future risks. Additional complexities arise from the pervasiveness of climate impacts and responses across natural and human systems, sectors and scales, the need to consider a range of time horizons, and the levels of uncertainty often involved.  However the development of products to support adaptation practice and decision-making is currently highly fragmented in Australia, leading to some confusion amongst end-users and insufficient critical mass and continuity of resourcing to provide sustained product support and improvement. For public, private and community sector organisations grappling with adaptation decisions there is a significant support gap, and an urgent need for products that will provide better guidance and more confidence. There is currently no national strategy to achieve this. This Project has carried out both research and strategy development to address this need. The Project concludes that the timing for a more coordinated strategic approach is right. There is potential to distil the learning from the investment of recent years. There is also a number of individual product initiatives under way or planned which, if positioned and enhanced within a more intentional overall strategy, could collectively make a significant difference. The timing is also critical. Australia’s adaptation effort is at a watershed. On the one hand the recent growth in experience and research is supporting progress by early adopters and especially those who have benefited from government seed funding. On the other, this has not yet brought about systemic change. In a future with more constrained government funding and most organisations still at first base, the foundation built to date could easily be lost. There is an urgent need to develop and promulgate good practices and products to better support organisations and decision-makers

Collaborative Multi-Resource Allocation in Terrestrial-Satellite Network Towards 6G

Terrestrial-satellite networks (TSNs) are envisioned to play a significant role in the sixth-generation (6G) wireless networks. In such networks, hot air balloons are useful as they can relay the signals between satellites and ground stations. Most existing works assume that the hot air balloons are deployed at the same height with the same minimum elevation angle to the satellites, which may not be practical due to possible route conflict with airplanes and other flight equipment. In this paper, we consider a TSN containing hot air balloons at different heights and with different minimum elevation angles, which creates the challenge of non-uniform available serving time for the communication between the hot air balloons and the satellites. Jointly considering the caching, computing, and communication (3C) resource management for both the ground-balloon-satellite links and inter-satellite laser links, our objective is to maximize the network energy efficiency. Firstly, by proposing a tapped water-filling algorithm, we schedule the traffic to relay among satellites according to the available serving time of satellites. Then, we generate a series of configuration matrices, based on which we formulate the relation between relay time and the power consumption involved in the relay among satellites. Finally, the collaborative resource allocation problem for TSN is modeled and solved by geometric programming with Taylor series approximation. Simulation results demonstrate the effectiveness of our proposed scheme