Floristic diversity and patch dynamics in hyper-disturbed tropical lowland rainforest fragments in north Queensland: no evidence for cyclone-disturbance and fragmentation driving species assemblages towards early-successional states

Tropical cyclones reshape the structure, composition and successional trajectories of forest ecosystems. Climate warming is expected to increase the intensity and impact of these storms while habitat fragmentation further modifies trajectories of response. Many studies over the past decade suggest that tropical forest fragments are locked into a future dominated by edge-favoured pioneer species, dramatic loss of late-successional, large-fruited species, and invasion by exotic weeds. However, this study shows that severely storm-damaged and fragmented tropical forests are remarkably resilient, with a capacity for rebuilding and maintaining plant species composition and diversity. My study followed two severe tropical cyclone events, Cyclones Larry (2006) and Yasi (2011) in the Australian Wet Tropics. To date, no comparable investigation has measured the effects of successive severe tropical cyclone events on different forest habitats in lowland rainforest. My study investigated: 1) immediate effects of a second severe cyclone on the structural characteristics of different forest habitat types; 2) family and species-level responses to damage and short-term survival rates; 3) plant community and species-level assemblages across different forest habitats; and 4) life-history successional characteristics of species for different habitat types. My results showed all trees sustained some level of damage (i.e. minor to severe) due to the effects of these two severe cyclone events. About 75% of trees had their main stem snapped compared to 11% of trees with major breakage of branches and less than 4% were uprooted. 10% of all trees sustained only minor damage including partial defoliation, twig-snapping and minor branches snapped. Snapping of tree trunks was higher in fragmented forest compared to continuous forest whereas snapping of major branches was significantly higher in continuous forest and edges. Trees resprouted within weeks of the cyclone and 96% of standing stems continued to show vigourous growth after eighteen months. Although there was a dramatic loss of large canopy and emergent trees during Cyclone Larry five years earlier, 83% of all stems in my plots were identified as belonging to mid-late and late successional species, while only 13% of stems were early-mid successional species. These stems are mainly saplings (≤ 10-20cm DBH) which have survived successive severe cyclone events within the understorey 'vine tangles.' I found no evidence for proliferation of early successional or pioneer species in any of the habitat types, including fragmented forest sites, within the time-frame of this study. No evidence was found for elevated levels of exotic weed invasion following these events with these species comprising less than 1% of total assemblages. All forest habitat types showed an unexpected capacity for resistance and resilience following the combined effects of fragmentation and two severe tropical cyclones. My data suggest that forest habitat types influence successional life-history characteristics but are not driving species assemblages in fragmented forests towards proliferation of short-lived, edge-favoured generalists (i.e. pioneer species)

Multilevel Security Policy Implementation Using OWL Ontology

This project is an experimental implementation of Multi-Level Security (MLS) lattice model by using semantic web technologies (OWL) to create and test Mandatory Access Control (MAC) with Bell-LaPadula (BLP) properties. Semantic web (web of data) is building on top of the World Wide Web (web of documents), aiming to make data machine-readable so that to improve data processing and management. OWL is a semantic web computational logic-base language which is designed to represent complex knowledge in semantic format. With the MLS ontology, we are able to define dominance relationship between variables within the lattice model and perform different queries to verify if the subject (with security clearance) can access (read/write) to the object (with security classification). Moreover, by leveraging BLP properties, the ontology would only allow information to flow from entities with lower classification to entities with higher classification

Characterization of the acoustic properties of cementitious materials

The primary aim of this research was to investigate the fundamental acoustic properties of several cementitious materials, the influence of mix design parameters/constituents, and finally the effect of the physical and mechanical properties of cementitious material concrete/mortar on the acoustic properties of the material. The main objectives were: To understand the mechanism of sound production in musical instruments and the effects of the material(s) employed on the sound generated; To build upon previous research regarding selection of the tested physical/mechanical properties and acoustic properties of cementitious materials; To draw conclusions regarding the effect of different constituents, mix designs and material properties upon the acoustic properties of the material; To build a model of the relationship between the acoustic properties of a cementitious material and its mix design via its physical/mechanical properties. In order to meet the aim, this research was conducted by employing the semi-experimental (half analytical) method: two experimental programmes were performed (I and II); a mathematical optimization technique (least square method) was then implemented in order to construct an optimized mathematical model to match with the experimental data. In Experimental Programme I, six constituents/factors were investigated regarding the effect on the physical/mechanical and acoustic properties: cementitious material additives (fly ash, silica fume, and GGBS), superplasticizer, and basic mix design parameters (w/c ratio, and sand grading). 11 properties (eight physical/mechanical properties: compressive strength, density, hardness, flexural strength, flexural modulus, elastic modulus, dynamic modulus and slump test; and three acoustic properties: resonant frequency, speed of sound and quality factor (internal damping)) were tested for each constituents/factors related mortar type. For each type of mortar, there were three cubes, three prisms and three cylinders produced. In Experimental Programme I, 20 mix designs were investigated, 180 specimens produced, and 660 test results recorded. After analysing the results of Experimental Programme I, fly ash (FA), w/b ratio and b/s ratio were selected as the cementitious material/factors which had the greatest influence on the acoustic properties of the material; these were subsequently investigated in detail in Experimental Programme II. In Experimental Programme II, various combinations of FA replacement level, w/b ratios and b/s ratios (three factors) resulted in 1122 test results. The relationship between these three factors on the selected 11 properties was then determined. Through using regression analysis and optimization technique (least square method), the relationship between the physical/mechanical properties and acoustic properties was then determined. Through both experimental programmes, 54 mix designs were investigated in total, with 486 specimens produced and tested, and 1782 test results recorded. Finally, based upon well-known existing relationships (including, model of compressive strength and elastic modulus, and the model of elastic modulus and dynamic modulus), and new regressioned models of FA-mortar (the relationship of compressive strength and constituents, which is unique for different mixes), the optimized object function of acoustic properties (speed of sound and damping ratio) and mix design (proportions of constituents) were constructed via the physical/mechanical properties

Assessing network risk with FRM: links with pricing kernel volatility and application to cryptocurrencies

The Financial Risk Meter (FRM) employs Quantile-LASSO regression to identify systemic financial risk and dependencies among tail events across financial assets. This paper establishes, both theoretically and empirically, a meaningful economic relationship between the FRM index, derived from the penalization parameter in quantile LASSO regression, and the volatility of assets' pricing kernels, the attainable maximal Sharpe ratio, and market volatility. Despite the rapid growth of the crypto market and its increasing integration with traditional financial markets, there remains a dearth of risk measures in this space. (Formula presented.) exhibits robust predictive capabilities in anticipating future market risk, potentially filling a critical void in this market

Transformation-based design method for the integration of green residential buildings and solar thermal collectors

This study investigates integrated application of solar thermal collectors (STCs), as green renewable energy, on the design of green residential buildings (GRBs). With the gradual increase of residential buildings, the use of solar thermal energy has be- come the main popularization and application mode for the integration of residential buildings and solar energy. Additionally, this study presents applicable solutions using the transformation-based design method to expand the functions of STCs through the integrated design of STCs and GRBs, thus laying a strong theoretical foundation for promoting the integrated design of solar water heaters and GRBs.This study investigates integrated application of solar thermal collectors (STCs), as green renewable energy, on the design of green residential buildings (GRBs). With the gradual increase of residential buildings, the use of solar thermal energy has be- come the main popularization and application mode for the integration of residential buildings and solar energy. Additionally, this study presents applicable solutions using the transformation-based design method to expand the functions of STCs through the integrated design of STCs and GRBs, thus laying a strong theoretical foundation for promoting the integrated design of solar water heaters and GRBs

Pre-positioning inventory and service outsourcing of relief material supply chain

Service outsourcing is very common in a commercial supply chain, and in humanitarian relief area the transportation service is usually outsourced. To practice relief supply more effectively, it seems essential to enlarge outsourcing from shipping to more areas, and private enterprises could play a vital role. This paper examines the optimal pre-disaster order quantity of a certain relief commodity, based on a two-stage coordinated approach. Our findings show that the delay cost, shortage penalty cost, risk of supply shortage, salvage value, expected perishable rate, unit inventory cost and reactive price have significant impacts on the optimal amount of propositioned inventory. Moreover, the outsourcing strategies differ by types of relief commodities. For perishable supplies, proactive or reactive outsourcing would improve the benefits of buyer and supplier simultaneously. As for imperishable supplies, it is better to combine proactive insourcing approach and reactive outsourcing strategy. In view of some supplies whose monitoring cost is high, the insourcing approach is much better than outsourcing approach

Still getting it on online: Thirty years of queer male spaces brokered through digital technologies

Research across the social sciences testifies to an ongoing relationship between queerness and digital technology. This article tracks how different online spaces for queer men have changed as the internet has developed over the past 30 years. It argues that queer spaces have become increasingly dominated by, and predicated on, internet technology. I review early interpretations of cyberspace as a liberatory space freed from heteronormativity and later more critical assessments of its potential, positioning arguments for and against the internet's status as a protective space. I then evaluate the huge popularity of mobile phone-based dating and hook-up apps such as Grindr and Tinder. These platforms have developed from static desktop offerings including Gaydar and PlanetRomeo, but emphasise a distinctly hybridised socio-technical experience in partner seeking. Finally, I consider the impact of locative media on more traditional queer concepts of cruising and community, concluding that contemporary apps refigure both structures in distinctive ways reflecting larger changes in sexuality and space studies

'Rock Guitar': optimising concrete properties for the manufacture of a concrete guitar

There is potential for cement-based materials to be used in making high-value customised musical instruments. This paper considers the properties (modulus, density, strength, and damping ratio) that a cement-based material requires to replicate traditional materials currently used in instrument production. Results are presented which demonstrate sound interaction with cementitious materials. A selection of mixes incorporating PVA, Lytag lightweight aggregate and normal sand mix with PVA were produced and tested with an impact hammer using the roving hammer technique and modal analysis in order to obtain the natural frequencies and damping ratio of the specimens. Lytag based mortars with PVA was determined as the optimum mix from the tests which was subsequently used to cast a workable full-size solid-bodied electric guitar, due to its lower elastic modulus and lower density compared to the normal compared mix, and its damping ratio in the region of wood (pine)

Infrared optical and mechanical properties of boron carbide thin films deposited by hydrogen-assisted pulsed DC sputtering

In this study, boron carbide thin films were deposited by microwave plasma-assisted pulsed DC sputtering system with hydrogen as reactive gas at different hydrogen flow rates. The design thickness of boron carbide thin film was 1200 nm, and the design thickness of transition layer amorphous Si was 500 nm. The substrates used were microslides, Ge, Si, Si wafer, GaAs and JGS3. Then, Fourier infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Vicker indenter were used to analyze the effects of hydrogen flow (0, 3, 7 and 10 mL/min) on the optical and mechanical properties of boron carbide thin films. As the results, the infrared optical transmittance and absorption rate could be improved by increasing the flow rate of hydrogen. At the same time, the increase of hydrogen could also reduce the stress of the coating, making it easy to adhere to the substrate. However, hydrogen reduced the hardness of boron carbide thin films.</p