Slotted cooperative communication in half duplex relay networks

In cooperative communication systems, several wireless communication terminals collaborate to form a virtual-multiple antenna array system and exploit the spatial diversity to achieve a better performance. This thesis proposes a practical slotted protocol for cooperative communication systems with half-duplex single antennas. The performance of the proposed slotted cooperative communication protocol is evaluated in terms of the pairwise error probability and the bit error rate. The proposed protocol achieves the multiple-input single-output performance bound with a novel relay ordering and scheduling strategy.

Crisis Communication in Natural Disasters : The Queensland Floods and Christchurch Earthquakes

Over the past decade, social media have gone through a process of legitimation and official adoption, and they are now becoming embedded as part of the official communications apparatus of many commercial and public-sector organisations— in turn, providing platforms like Twitter with their own sources of legitimacy. Arguably, the demonstrated utility of social media platforms and tools in times of crisis—from civil unrest and violent crime through to natural disasters like bushfires, earthquakes, and floods—has been a crucial driver of this newfound legitimacy. In the mid-2000s, user-created content and ‘Web 2.0’ platforms were known to play a role in crisis communication; back then, the involvement of extra-institutional actors in providing and sharing information around such events involved distributed, ad hoc, or niche platforms (like Flickr), and was more likely to be framed as ‘citizen journalism’ or ‘crowdsourcing’ (see, for example, Liu, Palen, Sutton, Hughes, & Vieweg, 2008, on the then-emerging role of photo-sharing in disasters). Since then, the dramatically increased take-up of mainstream social media platforms like Facebook and Twitter means that the pool of potential participants in online crisis communication has broadened to include a much larger proportion of the general population, as well as traditional media and official emergency response organisations.

Auditor communication in an evolving environment : going beyond SAS 600 auditors' reports on financial statements

In 1993 the Auditing Practices Board issued an expanded audit report, SAS 600 Auditors’ Reports on Financial Statements, in an attempt to educate users and to clarify certain matters pertaining to the audit function. This paper investigates the extent to which the new audit report, SAS 600, has been successful in aligning the views of auditors, preparers and users about issues dealt with in the expanded audit report, and the extent to which the three groups considered that it would be useful for additional matters, including corporate governance, to be reported upon by the auditor. Our findings suggest that SAS 600 has been successful in clarifying the purpose of the audit and the respective responsibilities of auditors and directors. However, to meet the expectations of users and to add more value, the audit report needs to provide more information about the findings of the audit.

Decentralised Communication in Autonomous Agent Swarms

Communication and information diffusion are typically difficult in situations where centralised structures may become unavailable. In this context, decentralised communication based on epidemic broadcast becomes essential. It can be seen as an opportunity-based flooding for message broadcasting within a swarm of autonomous agents, where each entity tries to share the information it possesses with its neighbours. As an example of applications for such a system, we present simulation results where agents have to coordinate to map an unknown area.

Negotiating indeterminacy in studio teaching: Using the zones of material and immaterial play to shape pedagogies and practices in art

The processes of studio-based teaching in visual art are often still tied to traditional models of discrete disciplines and largely immersed in skill-based learning. These approaches to training artists are also tied to an individual model of art practice that is clearly defined by the boundaries of those disciplines. This paper will explain how the open studio program at QUT can be broadly understood as an action research model of learning that ‘plays’ with the post-medium, post-studio genealogies and zones of contemporary art. This emphasises developing conceptual, contextual and formal skills as essential for engaging with and practicing in the often-indeterminate spatio-temporal sites of studio teaching. It will explore how this approach looks to Sutton-Smith’s observations on the role of play and Vygotsky’s zone of proximal development in early childhood learning as a way to develop strategies for promoting creative learning environments that are collaborative and self sustainable. Social, cultural, political and philosophical dialogues are examined as they relate to art practice with the aim of forming the shared interests, aims, and ambitions of graduating students into self initiated collectives or ARIs.

Women's perceptions of communication in pregnancy and childbirth: Influences on participation and satisfaction with care

In this study, 3531 Queensland women, who had recently given birth, completed a questionnaire that included questions about their participation in decision making during pregnancy, their ratings of client centred care and perceived quality of care. These data tested a version of Street’s (2001) linguistic model of patient participation in care (LMOPPC), adapted to the maternity context. We investigated how age and education influenced women’s perceptions of their participation and quality of care. Hierarchical multiple regressions revealed that women’s perceived ability to make decisions, and the extent of client-centred communication with maternity care providers were the most influential predictors of participation and perceived quality of care. Participation in care predicted perceived quality of care, but the influence of client-centred communication by a care provider and a woman’s confidence in decision making were stronger predictors of perceived quality of care. Age and education level were not important predictors. These findings extend and support the use of LMOPPC in the maternity context.

Increasing autonomy transparency through capability communication in multiple heterogeneous UAV management

Interest in the area of collaborative Unmanned Aerial Vehicles (UAVs) in a Multi-Agent System is growing to compliment the strengths and weaknesses of the human-machine relationship. To achieve effective management of multiple heterogeneous UAVs, the status model of the agents must be communicated to each other. This paper presents the effects on operator Cognitive Workload (CW), Situation Awareness (SA), trust and performance by increasing the autonomy capability transparency through text-based communication of the UAVs to the human agents. The results revealed a reduction in CW, increase in SA, increase in the Competence, Predictability and Reliability dimensions of trust, and the operator performance.

Leveraging coherent distributed space-time codes for noncoherent communication in relay networks via training

For point to point multiple input multiple output systems, Dayal-Brehler-Varanasi have proved that training codes achieve the same diversity order as that of the underlying coherent space time block code (STBC) if a simple minimum mean squared error estimate of the channel formed using the training part is employed for coherent detection of the underlying STBC. In this letter, a similar strategy involving a combination of training, channel estimation and detection in conjunction with existing coherent distributed STBCs is proposed for noncoherent communication in Amplify-and-Forward (AF) relay networks. Simulation results show that the proposed simple strategy outperforms distributed differential space-time coding for AF relay networks. Finally, the proposed strategy is extended to asynchronous relay networks using orthogonal frequency division multiplexing.

Intercellular Communication in the Multicellular Stage of Dictyostelium-Discoideum

The aim of the present study was to draw inferences regarding the properties of single cells responsible for co-operative behaviour in the slug of the soil amoeba Dictyostelium discoideum. The slug is an integrated multicellular mass formed by the aggregation of starved cells. The amoebae comprising the slug differentiate according to their spatial locations relative to one another, implying that, as in the case of other regulative embryos, they must be in mutual communication. We have previously shown that one manifestation of this communication is the time taken for the anteriormost fragment of the slug, the tip, to regenerate from slugs which have been rendered tipless by amputation. We present results of tip-regeneration experiments performed on genetically mosaic slugs. By comparing the mosaics with their component pure genotypes, we were able to discriminate between a set of otherwise equally plausible modes of intercellular signalling. Neither a'pacemaker' model, in which the overall rate of tip regeneration is determined by the cell with the highest frequency of autonomous oscillation, nor an 'independent-particle' model, in which the rate of regeneration is the arithmetical average of independent cell-dependent rates, is in quantitative accord with our findings. Our results are best explained by a form of signalling which operates by means of cell-to-cell relay. Therefore intercellular communication Seems to be essential for tip regeneration.

Personality and social psychological studies on computer-mediated communication in school settings

The present study examined how personality and social psychological factors affect third and fourth graders' computer-mediated communication. Personality was analysed in terms of the following strategies: optimism, pessimism and defensive pessimism. Students worked either individually or in dyads which were paired homogeneously or heterogeneously according to the strategies. Moreover, the present study compared horizontal and vertical interaction. The study also examined the role that popularity plays, and students were divided into groups based on their popularity level. The results show that an optimistic strategy is useful. Optimism was found to be related to the active production and processing of ideas. Although previous research has identified drawbacks to pessimism in achievement settings, this study shows that the pessimistic strategy is not as debilitating a strategy as is usually assumed. Pessimistic students were able to process their ideas. However, defensive pessimists were somewhat cautious in introducing or changing ideas. Heterogeneous dyads were not beneficial configurations with respect to producing, introducing, or changing ideas. Moreover, many differences were found to exist between the horizontal and vertical interaction; specifically, the students expressed more opinions and feelings when teachers took no part in the discussions. Strong emotions were observed especially in the horizontal interaction. Further, group working skills were found to be more important for boys than for girls, while rejected students were not at a disadvantage compared to popular ones. Schools can encourage emotional and social learning. The present study shows that students can use computers to express their feelings. In addition, students who are unpopular in non-computer contexts or students who use pessimism can benefit from computers. Participation in computer discussions can give unpopular children a chance to develop confidence when relating to peers.

Two Tools for Interprocess Communication in Distributed Data-Flow Systems

Abstract is not available.

Ligand dependent intra and inter subunit communication in human tryptophanyl tRNA synthetase as deduced from the dynamics of structure networks

Homodimeric protein tryptophanyl tRNA synthetase (TrpRS) has a Rossmann fold domain and belongs to the 1c subclass of aminoacyl tRNA synthetases. This enzyme performs the function of acylating the cognate tRNA. This process involves a number of molecules (2 protein subunits, 2 tRNAs and 2 activated Trps) and thus it is difficult to follow the complex steps in this process. Structures of human TrpRS complexed with certain ligands are available. Based on structural and biochemical data, mechanism of activation of Trp has been speculated. However, no structure has yet been solved in the presence of both the tRNA(Trp) and the activated Trp (TrpAMP). In this study, we have modeled the structure of human TrpRS bound to the activated ligand and the cognate tRNA. In addition, we have performed molecular dynamics (MD) simulations on these models as well as other complexes to capture the dynamical process of ligand induced conformational changes. We have analyzed both the local and global changes in the protein conformation from the protein structure network (PSN) of MD snapshots, by a method which was recently developed in our laboratory in the context of the functionally monomeric protein, methionyl tRNA synthetase. From these investigations, we obtain important information such as the ligand induced correlation between different residues of this protein, asymmetric binding of the ligands to the two subunits of the protein as seen in the crystal structure analysis, and the path of communication between the anticodon region and the aminoacylation site. Here we are able to elucidate the role of dimer interface at a level of detail, which has not been captured so far.

Role of information and communication in redefining unmanned aerial vehicle autonomous control levels

Autonomous mission control, unlike automatic mission control which is generally pre-programmed to execute an intended mission, is guided by the philosophy of carrying out a complete mission on its own through online sensing, information processing, and control reconfiguration. A crucial cornerstone of this philosophy is the capability of intelligence and of information sharing between unmanned aerial vehicles (UAVs) or with a central controller through secured communication links. Though several mission control algorithms, for single and multiple UAVs, have been discussed in the literature, they lack a clear definition of the various autonomous mission control levels. In the conventional system, the ground pilot issues the flight and mission control command to a UAV through a command data link and the UAV transmits intelligence information, back to the ground pilot through a communication link. Thus, the success of the mission depends entirely on the information flow through a secured communication link between ground pilot and the UAV In the past, mission success depended on the continuous interaction of ground pilot with a single UAV, while present day applications are attempting to define mission success through efficient interaction of ground pilot with multiple UAVs. However, the current trend in UAV applications is expected to lead to a futuristic scenario where mission success would depend only on interaction among UAV groups with no interaction with any ground entity. However, to reach this capability level, it is necessary to first understand the various levels of autonomy and the crucial role that information and communication plays in making these autonomy levels possible. This article presents a detailed framework of UAV autonomous mission control levels in the context of information flow and communication between UAVs and UAV groups for each level of autonomy.