The Metapopulation Dynamics of an Infectious Disease: Tuberculosis in Possums

An SEI metapopulation model is developed for the spread of an infectious agent by migration. The model portrays two age classes on a number of patches connected by migration routes which are used as host animals mature. A feature of this model is that the basic reproduction ratio may be computed directly, using a scheme that separates topography, demography, and epidemiology. We also provide formulas for individual patch basic reproduction numbers and discuss their connection with the basic reproduction ratio for the system. The model is applied to the problem of spatial spread of bovine tuberculosis in a possum population. The temporal dynamics of infection are investigated for some generic networks of migration links, and the basic reproduction ratio is computed—its value is not greatly different from that for a homogeneous model. Three scenarios are considered for the control of bovine tuberculosis in possums where the spatial aspect is shown to be crucial for the design of disease management operations

The validation of the rating for subdivision neighbourhood sustainability design (RSNSD) In Bangkok Metropolitan Region (BMR), Thailand

In recent years, the problems resulting from unsustainable subdivision development have become significant problems in the Bangkok Metropolitan Region (BMR), Thailand. Numbers of government departments and agencies have tried to eliminate the problems by introducing the rating tools to encourage the higher sustainability levels of subdivision development in BMR, such as the Environmental Impact Assessment Monitoring Award (EIA-MA) and the Thai’s Rating for Energy and Environmental Sustainability of New construction and major renovation (TREES-NC). However, the EIA-MA has included the neighbourhood designs in the assessment criteria, but this requirement applies to large projects only. Meanwhile, TREES-NC has focused only on large scale buildings such as condominiums, office buildings, and is not specific for subdivision neighbourhood designs. Recently, the new rating tool named “Rating for Subdivision Neighbourhood Sustainability Design (RSNSD)” has been developed. Therefore, the validation process of RSNSD is still required. This paper aims to validate the new rating tool for subdivision neighbourhood design in BMR. The RSNSD has been validated by applying the rating tool to eight case study subdivisions. The result of RSNSD by data generated through surveying subdivisions will be compared to the existing results from the EIA-MA. The selected cases include of one “Excellent Award”, two “Very Good Award”, and five non-rated subdivision developments. This paper expects to prove the credibility of RSNSD before introducing to the real subdivision development practises. The RSNSD could be useful to encourage higher sustainability subdivision design level, and then protect the problems from further subdivision development in BMR.

Data flow analysis of embedded program expressions

Data flow analysis techniques can be used to help assess threats to data confidentiality and integrity in security critical program code. However, a fundamental weakness of static analysis techniques is that they overestimate the ways in which data may propagate at run time. Discounting large numbers of these false-positive data flow paths wastes an information security evaluator's time and effort. Here we show how to automatically eliminate some false-positive data flow paths by precisely modelling how classified data is blocked by certain expressions in embedded C code. We present a library of detailed data flow models of individual expression elements and an algorithm for introducing these components into conventional data flow graphs. The resulting models can be used to accurately trace byte-level or even bit-level data flow through expressions that are normally treated as atomic. This allows us to identify expressions that safely downgrade their classified inputs and thereby eliminate false-positive data flow paths from the security evaluation process. To validate the approach we have implemented and tested it in an existing data flow analysis toolkit.

Volatile properties of particles emitted by compressed natural gas and diesel buses during steady state and transient driving modes

Volatile properties of particle emissions from four compressed natural gas (CNG) and four diesel buses were investigated under steady state and transient driving modes on a chassis dynamometer. The exhaust was diluted utilising a full-flow continuous volume sampling system and passed through a thermodenuder at controlled temperature. Particle number concentration and size distribution were measured with a condensation particle counter and a scanning mobility particle sizer, respectively. We show that, while almost all the particles emitted by the CNG buses were in the nanoparticle size range, at least 85% and 98% were removed at 100ºC and 250ºC, respectively. Closer analysis of the volatility of particles emitted during transient cycles showed that volatilisation began at around 40°C with the majority occurring by 80°C. Particles produced during hard acceleration from rest exhibited lower volatility than that produced during other times of the cycle. Based on our results and the observation of ash deposits on the walls of the tailpipes, we suggest that these non-volatile particles were composed mostly of ash from lubricating oil. Heating the diesel bus emissions to 100ºC removed ultrafine particle numbers by 69% to 82% when a nucleation mode was present and just 18% when it was not.

Aggregate distance based clustering using Fibonacci Series -FIBCLUS

This paper proposes an innovative instance similarity based evaluation metric that reduces the search map for clustering to be performed. An aggregate global score is calculated for each instance using the novel idea of Fibonacci series. The use of Fibonacci numbers is able to separate the instances effectively and, in hence, the intra-cluster similarity is increased and the inter-cluster similarity is decreased during clustering. The proposed FIBCLUS algorithm is able to handle datasets with numerical, categorical and a mix of both types of attributes. Results obtained with FIBCLUS are compared with the results of existing algorithms such as k-means, x-means expected maximization and hierarchical algorithms that are widely used to cluster numeric, categorical and mix data types. Empirical analysis shows that FIBCLUS is able to produce better clustering solutions in terms of entropy, purity and F-score in comparison to the above described existing algorithms.

Natural convection in a triangular enclosure due to non-uniform cooling on top

Natural convection in a triangular enclosure subject to non-uniformly cooling at the inclined surfaces and uniformly heating at the base is investigated numerically. The numerical simulations of the unsteady flows over a range of Rayleigh numbers and aspect ratios are carried out using Finite Volume Method. Since the upper surface is cooled and the bottom surface is heated, the air flow in the enclosure is potentially unstable to Rayleigh Benard instability. It is revealed that the transient flow development in the enclosure can be classified into three distinct stages; an early stage, a transitional stage and a steady stage. It is also found that the flow inside the enclosure strongly depends on the governing parameters, Rayleigh number and aspect ratio. The asymmetric behaviour of the flow about the geometric centre line is discussed in detailed. The heat transfer through the roof and the ceiling as a form of Nusselt number is also reported in this study.

Declining youth membership : the views of union officials

Across the industrialized west there has been a sharp decline in union membership (Frege and Kelly2003, Peetz 2002). Even more alarming are the lower unionization rates of young people and the steeper decline in these rates compared to older workers (Serrano and Waddington 2000). At the same time increasing numbers of young people still at school are participating in the labour market. There have been a number of explorations internationally of young people's union membership, but most either track membership decline over time, comparing adult and youth union density (Blanden and Machin 2003, Bryson et al. 2005, Haynes, Vowles and Boxall 2005, Canny 2002, OECD 2006), explore the general experience of young people in the labour market (for example, Lizen, Bolton and Pole 1999) or examine young people's view of unions (for example, Bulbeck 2008). This chapter however takes a different approach, exploring union officials' constructions of 'the problem' of low union density amongst youth. While the data in this study was obtained from Australia, the Australian context has strong similarities with those in other industrialized economies, not least because globalization has meant the spread of neo-liberal industrial relations (IR) policies and structures. Assuming that unions have choices open to them as to how they recruit and retain young people, it is important to analyse officials' construction of 'the problem', as this affects union strategizing and action.

A majority experience: young people’s encounters with the labour market

Young people are frequently the focus of study in social science. Education, employment, leisure, criminality and family life are all spheres within which the different experiences of young people have been examined (Pollock 2008). A still relatively small, but expanding strand of this broader scholarship addressing youth-related issues is a body of theoretical and empirical literature which focuses on young people's participation in work. This growing interest in young people's employment has followed a significant shift in many western societies. Younger and much larger numbers of young people, still engaged in full time education, are entering the formal labour market. Indeed, in many countries, employment is a majority experience for children (Hobbs and McKechnie 1997), and for young people in general. While in such work there has been a tendency to blur definitional lines, here we adopt the term 'young people' which incorporates the definitions of 'children' as those under 18 years and 'youth' as those under 24 (UN n.d.).

Mixed convection laminar flow along a horizontal plate subject to streamwise sinusoidal surface temperature

Mixed convection of a two-dimensional laminar incompressible flow along a horizontal flat plate with streamwise sinusoidal surface temperature has been numerically investigated for different values of Rayleigh number and Reynolds number for constant values of Prandtl number, amplitude and frequency of periodic temperature. The numerical scheme is based on the finite element method adapted to rectangular non-uniform mesh elements by a non-linear parametric solution algorithm. The fluid considered in this study is air. The results are obtained for the Rayleigh number and Reynolds number ranging from 102 to 104 and 1 to 100, respectively, with constant physical properties for the fluid medium considered. Velocity and temperature profiles, streamlines, isotherms, and average Nusselt numbers are presented to observe the effect of the investigating parameters on fluid flow and heat transfer characteristics. The present results show that the convective phenomena are greatly influenced by the variation of Rayleigh numbers and Reynolds number.

No longer Singaporean : visibilising the everyday contestations of identities

In the past decade or so, the citizens of Singapore have been vigorously urged by the state to turn their cultural and linguistic affinities with China to economic advantage. At the same time, the city-state has opened its doors to selected, skilled migrants from Asia including many of those from mainland and Greater China. These concurrent emphases have coincided with the trend and growing numbers of Singaporeans heading overseas for one reason or another. Through a reflexive journey sparked by a recent visit, I argue in this paper that the resultant change in the makeup of its population produces tensions that may well have important repercussions for a nation that is constitutionally multiethnic though pragmatically meritocratic. However, because these frictions find form only in everyday, pedestrian practices, they are often dismissed or ignored. It is my contention that as the stage on which innocuous, creeping shifts in social identities are enacted, finessed and (re)embedded into social imaginaries, these everyday contestations of identities need to studied for indications of what is at stake.

Effect of differentially heating and consequent transient behaviour for natural convection within an enclosure of sinusoidal corrugated side walls

Unsteady natural convection due to differentially heating of the sinusoidal corrugated side walls of a modified square enclosure has been numerically investigated. The fluid inside the enclosure is air, initially as quiescent. The flat top and bottom surfaces are considered as adiabatic. The numerical scheme is based on the finite element method adapted to triangular non-uniform mesh element by a non-linear parametric solution algorithm. The results are obtained for the Rayleigh number, Ra ranging from 1e+05 to 1e+08 for different corrugation amplitude and frequency with constant physical properties for the fluid medium considered. The streamlines, isotherms and average Nusselt numbers are presented to observe the effect of sudden heating and its consequent transient behavior on fluid flow and heat transfer characteristics for the range of governing parameters. The present results show that the transient phenomena are greatly influenced by the variation of the aforementioned parameters.

Web searcher interaction with the Dogpile.com metasearch engine

Metasearch engines are an intuitive method for improving the performance of Web search by increasing coverage, returning large numbers of results with a focus on relevance, and presenting alternative views of information needs. However, the use of metasearch engines in an operational environment is not well understood. In this study, we investigate the usage of Dogpile.com, a major Web metasearch engine, with the aim of discovering how Web searchers interact with metasearch engines. We report results examining 2,465,145 interactions from 534,507 users of Dogpile.com on May 6, 2005 and compare these results with findings from other Web searching studies. We collect data on geographical location of searchers, use of system feedback, content selection, sessions, queries, and term usage. Findings show that Dogpile.com searchers are mainly from the USA (84% of searchers), use about 3 terms per query (mean = 2.85), implement system feedback moderately (8.4% of users), and generally (56% of users) spend less than one minute interacting with the Web search engine. Overall, metasearchers seem to have higher degrees of interaction than searchers on non-metasearch engines, but their sessions are for a shorter period of time. These aspects of metasearching may be what define the differences from other forms of Web searching. We discuss the implications of our findings in relation to metasearch for Web searchers, search engines, and content providers.

Design and design thinking in business and management education and development

Design and design thinking have been identified as making valuable contributions to business and management and the numbers of higher education programs that teach design thinking to business students, managers and executives are growing. However multiple definitions of design thinking and the range of perspectives have created some confusion about potential pathways. This paper examines notions of design and design thinking and uses these definitions to identify themes in higher educational programs. We present the findings from an initial exploratory investigation of design and design thinking in higher education business programs and define four distinct educational approaches around human centred innovation, integrative thinking, design management and design as strategy. Potential directions for management education programs are presented.

Central Queensland Mining Supplies Pty Ltd v Columbia Steel Casting Co Ltd

In Central Queensland Mining Supplies Pty Ltd v Columbia Steel Casting Co Ltd [2011] QSC 183 Applegarth J considered complaints made by the defendant about the approach the plaintiff had taken in its endeavour to comply with its disclosure obligation under r 211 of the Uniform Civil Procedure Rules 1999 (Qld). The judgment also provides an indication of the direction the court is taking in relation to disclosure and document management in matters involving large numbers of documents.

Market Trend Analysis of Purpose Built Office (PBO) in Malaysia

The purpose of this paper is to explore the trend of Purpose Built Office (PBO) supply and occupancy in Malaysia. In achieving this, the number of PBO supply by the private sector in the market is compared with the government sector to gain an understanding of the current emerging market for the PBO. There have been limited studies in Malaysia comparing the trend supply and occupancy of PBOs by both sectors. This paper outcome will illustrate the needs for public sector asset management in Malaysia, particularly for PBOs. An analytical framework is developed using time series to measure the level of supply and occupancy of PBO by both sectors, indicating the percentage of government’s PBO compared to the total numbers of PBOs in the market from 2004 to 2010