Optimal HMM filtering and decision feedback equalisation for differential encoded transmission systems

In this paper conditional hidden Markov model (HMM) filters and conditional Kalman filters (KF) are coupled together to improve demodulation of differential encoded signals in noisy fading channels. We present an indicator matrix representation for differential encoded signals and the optimal HMM filter for demodulation. The filter requires O(N3) calculations per time iteration, where N is the number of message symbols. Decision feedback equalisation is investigated via coupling the optimal HMM filter for estimating the message, conditioned on estimates of the channel parameters, and a KF for estimating the channel states, conditioned on soft information message estimates. The particular differential encoding scheme examined in this paper is differential phase shift keying. However, the techniques developed can be extended to other forms of differential modulation. The channel model we use allows for multiplicative channel distortions and additive white Gaussian noise. Simulation studies are also presented.

Financial literacy and superannuation investment decision-making in a choice environment : an exploratory study

This thesis examines superannuation fund members' level of financial literacy and its association with investment choice decisions in the setting of the mandatory superannuation system in Australia. It also investigates a range of contextual and socio-demographic factors in explaining financial literacy and investment choice. The empirical analysis shows that while most survey respondents displayed high levels of self-rated and general financial literacy, fewer scored as well in relation to more advanced literacy regarding superannuation investment options. The findings of this study have important implications for policy-makers and the superannuation industry in educating and engaging with fund members.

"The red dress or the blue?" How do staff perceive that they support decision making for people with dementia living in residential aged care facilities?

Respect for a person's right to make choices and participate in decision making is generally seen as central to quality of life and well-being. When a person moves into a residential aged care facility (RACF), however, decision making becomes more complicated, particularly if the person has a diagnosis of dementia. Little is known about how staff in RACFs perceive that they support decision making for people with dementia within their everyday practice, and this article seeks to address this knowledge gap. The article reports on the findings of a qualitative study conducted in the states of Victoria and Queensland, Australia with 80 direct care staff members. Findings revealed that the participants utilized a number of strategies in their intention to support decision making for people with dementia, and had an overall perception that "a little effort goes a long way."

Towards a theory of individual-level discontinuance of information systems use

I develop a model of individuals’ intentions to discontinue information system use. Understanding these intentions is important because they give insights into users’ willingness to carry out system tasks, and provide a basis for maintenance decisions as well as possible replacement decisions. I offer a first conceptualization of factors determining users’ discontinuance intentions on basis of existing literature on technology use, status quo bias and dual factor concepts. The model is grounded in rational choice theory to distinguish determinants of a conscious decision between continuing or discontinuing IS use. I provide details on the empirical test of the model through a field study of IS users in a retail organization. The work will have implications for theory on information systems continuance and dual-factor logic in information system use. The empirical findings will provide suggestions for managers dealing with cessation of information systems and work routine changes in organizations.

Causes of rigidity in SMEs' export commencement decision

Today, small-medium sized enterprises (SMEs) collectively contribute to the largest percentage of job creation in OECD countries. SMEs have become increasingly international since the turn of the century despite being smaller in size in comparison to large multinational firms, and notably, exporting is the most favoured mode of international market entry utilised by SMEs in their internationalisation strategy. Governments around the world have acknowledged the importance of export promotion and have employed policies that are targeted at increasing the export activity of SMEs. However, in many countries, the involvement of SMEs in export operations remains rather low. Within Australia, for example, only about one-third of local SMEs are exporting and this raises an important question as to why there is such a huge percentage of non-exporters. Much scholarly research that focuses on this problem has concentrated on the broad concept of 'export barriers' that act as obstacles to a firm's export development. This paper takes a different approach to previous studies and proposes that a firm's resistance to commence exporting can be better understood through an analysis of the behavioural decision process during its pre-export state. Using a sample of Australian SMEs, the factors that are important in preventing a firm’s initial export commencement decision are categorised and discussed through the use of factor analysis.

The decision-making processes of early childhood teachers when working with children experiencing parental separation and divorce

In this study, the pedagogical decision-making processes of 21 Australian early childhood teachers working with children experiencing parental separation and divorce were examined. Transcripts from interviews and a focus group with teachers were analysed using grounded theory methodology. The findings showed that as teachers interacted with young children experiencing parental separation and divorce, they reported using strategic, reflexive pedagogical decision-making processes. These processes comprised five stages: (1) teachers constructing their knowledge; (2) teachers thinking about their knowledge; (3) teachers using decision-making schemas; (4) teachers taking action, and; (5) teachers monitoring action and evaluating. This understanding of teachers’ reflexive pedagogical decision-making is useful for identifying how teachers and educational leaders can support children experiencing parental separation and divorce or other life challenges.

Comparison of nanostructures obtained from galvanic replacement in water and an ionic liquid for applications in electrocatalysis and SERS

We demonstrate potential applications for unusual dendrite like Au–Ag alloy nanoparticles formed via a galvanic replacement reaction in the ionic liquid [BMIM][BF4]. In comparison to Au–Ag alloy nanoshells synthesised via a similar reaction in water, the unusual branched structure of the dendritic materials led to increased electrocatalytic activity for the oxidation of both formaldehyde and hydrazine, and increased sensitivity and spectral resolution for the surface enhanced Raman scattering (SERS) of 4,4-bipyridal.

Reinforcing guardianship regimes through assisted decision-making : a Scottish perspective

Guardianship laws which provide legal mechanisms for decision-making on behalf of adults with limited or impaired capacity to make decisions have become a feature of most Western jurisdictions. In the UK, the Adults with Incapacity (Scotland) Act 2000 and the English and Welsh Mental Capacity Act 2005 have established a comprehensive framework for authorising medical, financial and welfare decisions to be taken on behalf of adults who are unable to take any or all such decisions themselves. One feature of guardianship regimes has been their tendency to evolve over time. Legal reforms have been instigated by the changes in philosophical views about how society should engage with adults with a decision-making impairment and also modern views about the role human rights play in guardianships regimes. The latest ideas in guardianship regimes around the Western world centre on the possibility of legal recognition of the concept of assisted decision-making...

Decision support for the efficient annotation of bioacoustic events

Acoustic sensors allow scientists to scale environmental monitoring over large spatiotemporal scales. The faunal vocalisations captured by these sensors can answer ecological questions, however, identifying these vocalisations within recorded audio is difficult: automatic recognition is currently intractable and manual recognition is slow and error prone. In this paper, a semi-automated approach to call recognition is presented. An automated decision support tool is tested that assists users in the manual annotation process. The respective strengths of human and computer analysis are used to complement one another. The tool recommends the species of an unknown vocalisation and thereby minimises the need for the memorization of a large corpus of vocalisations. In the case of a folksonomic tagging system, recommending species tags also minimises the proliferation of redundant tag categories. We describe two algorithms: (1) a “naïve” decision support tool (16%–64% sensitivity) with efficiency of O(n) but which becomes unscalable as more data is added and (2) a scalable alternative with 48% sensitivity and an efficiency ofO(log n). The improved algorithm was also tested in a HTML-based annotation prototype. The result of this work is a decision support tool for annotating faunal acoustic events that may be utilised by other bioacoustics projects.

Hybrid CuTCNQ/AgTCNQ metal-organic charge transfer complexes via galvanic replacement vs. corrosion recrystallization

This study reports a hybrid of two metal-organic semiconductors that are based on organic charge transfer complexes of 7,7,8,8-tetracyanoquinodimethane (TCNQ). It is shown that the spontaneous reaction between semiconducting microrods of CuTCNQ with Ag+ ions leads to the formation of a CuTCNQ/AgTCNQ hybrid, both in aqueous solution and acetonitrile, albeit with completely different reaction mechanisms. In an aqueous environment, the reaction proceeds by a complex galvanic replacement (GR) mechanism, wherein in addition to AgTCNQ nanowires, Ag0 nanoparticles and Cu(OH)2 crystals decorate the surface of CuTCNQ microrods. Conversely, in acetonitrile, a GR mechanism is found to be thermodynamically unfavorable and instead a corrosion-recrystallization mechanism leads to the decoration of CuTCNQ microrods with AgTCNQ nanoplates, resulting in a pure CuTCNQ/AgTCNQ hybrid metal-organic charge transfer complex. While hybrids of two different inorganic semiconductors are regularly reported, this report pioneers the formation of a hybrid involving two metal-organic semiconductors that will expand the scope of TCNQ-based charge transfer complexes for improved catalysis, sensing, electronics and biological applications.