Co-ordinate Interleaved Distributed Space-Time Coding for Two-Antenna-Relays Networks

Distributed space time coding for wireless relay networks when the source, the destination and the relays have multiple antennas have been studied by Jing and Hassibi. In this set-up, the transmit and the receive signals at different antennas of the same relay are processed and designed independently, even though the antennas are colocated. In this paper, a wireless relay network with single antenna at the source and the destination and two antennas at each of the R relays is considered. A new class of distributed space time block codes called Co-ordinate Interleaved Distributed Space-Time Codes (CIDSTC) are introduced where, in the first phase, the source transmits a T-length complex vector to all the relays;and in the second phase, at each relay, the in-phase and quadrature component vectors of the received complex vectors at the two antennas are interleaved and processed before forwarding them to the destination. Compared to the scheme proposed by Jing-Hassibi, for T >= 4R, while providing the same asymptotic diversity order of 2R, CIDSTC scheme is shown to provide asymptotic coding gain with the cost of negligible increase in the processing complexity at the relays. However, for moderate and large values of P, CIDSTC scheme is shown to provide more diversity than that of the scheme proposed by Jing-Hassibi. CIDSTCs are shown to be fully diverse provided the information symbols take value from an appropriate multidimensional signal set.

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.

Maintaining student engagement in a multidisciplinary allied health communication skills course

Effective communication is an important graduate capability for allied health students but there are few opportunities for students to engage with these skills in a dedicated manner at an undergraduate level. This paper reported on the use of active learning and relevance-building strategies to maintain student engagement in a multidisciplinary allied health communication skills course at an Australian university. Students (N = 736) completed an engagement survey during the first and final lecture. While most degree programs reported no difference in engagement across semester, nursing/paramedic students reported a significant decrease in student engagement. A perceived lack of disciplinary relevance may account for student disengagement in this group, illustrating the challenge of delivering an authentic learning experience whilst engaging students from diverse degree programs.

Low PAPR Square STBCs from Complex Partial-Orthogonal Designs (CPODs)

Space-time codes from complex orthogonal designs (CODs) with no zero entries offer low Peak to Average Power Ratio (PAPR) and avoid the problem of switching off antennas. But square CODs for 2(a) antennas with a + 1. complex variables, with no zero entries were discovered only for a <= 3 and if a + 1 = 2(k), for k >= 4. In this paper, a method of obtaining no zero entry (NZE) square designs, called Complex Partial-Orthogonal Designs (CPODs), for 2(a+1) antennas whenever a certain type of NZE code exists for 2(a) antennas is presented. Then, starting from a so constructed NZE CPOD for n = 2(a+1) antennas, a construction procedure is given to obtain NZE CPODs for 2n antennas, successively. Compared to the CODs, CPODs have slightly more ML decoding complexity for rectangular QAM constellations and the same ML decoding complexity for other complex constellations. Using the recently constructed NZE CODs for 8 antennas our method leads to NZE CPODs for 16 antennas. The class of CPODs do not offer full-diversity for all complex constellations. For the NZE CPODs presented in the paper, conditions on the signal sets which will guarantee full-diversity are identified. Simulation results show that bit error performance of our codes is same as that of the CODs under average power constraint and superior to CODs under peak power constraint.

Improving health and safety communication of migrant construction workers

Although statistical data in some developed countries indicate that migrant workers are nearly 30% more likely to have work-related injuries than local workers, no equivalent official injury/ incident statistics on the health and safety (H&S) of migrant workers are currently tracked in Australia. With increasing numbers of migrant workers having joined Australia’s extractive industries infrastructure and commercial construction industry, this suggests the need for some investigation. A particular issue is that lack of H&S communication is one of the key factors leading to construction industry accidents/ incidents as it prevents workers from effectively receiving H&S safety training and acquiring H&S information. Migrant workers whose first languages are not English are particularly affected by this problem and ways are needed to improve their situation. The research aims to do this by evaluating the H&S communication problems of migrant workers and identify an effective H&S communication structure. An overview of the challenge being addressed by the research is firstly provided, followed by a description of the research framework, and a report of the initial findings, from which recommendations are provided for improving H&S performance in the construction industry.

A design history of design: Complexity, criticality & cultural competence

Les histoires de l’art et du design ont délaissé, au cours desquatre dernières décennies, l’étude canonique des objets, des artistes/concepteurs et des styles et se sont tournées vers des recherches plus interdisciplinaires. Nous soutenons néanmoins que les historiens et historiennes du design doivent continuer de pousser leur utilisation d’approches puisant dans la culturelle matérielle et la criticalité afin de combler des lacunes dans l’histoire du design et de développer des méthodes et des approches pertinentes pour son étude. Puisant dans notre expérience d’enseignement auprès de la génération des « milléniaux », qui sont portés vers un « design militant », nous offrons des exemples pédagogiques qui ont aidé nos étudiants et étudiantes à assimiler des histoires du design responsables, engagées et réflexives et à comprendre la complexité et la criticalité du design.

Poetics of Subjectivity : Existence and Expressivity in Simone de Beauvoir's Philosophy

In the last thirty years, primarily feminist scholars have drawn attention to and re-evaluated the philosophy of Simone de Beauvoir (1908 1986). Her philosophical practice has been described as non-systematic, and her literary writing has been viewed as part of her non-systematic mode of philosophising. This dissertation radically deepens the question concerning Beauvoir s philosophical motivations for turning to literature as a mode to express subjectivity. It explicates the central concepts of Beauvoir s philosophy of existence, which are subjectivity, ambiguity, paradox and temporality, and their background in the modern traditions of existential philosophy and phenomenology. It also clarifies Beauvoir s main reason to turn to literature in order to express subjectivity as both singular and universal: as a specific mode of communication, literature is able to make the universality of existence manifest in the concrete, singular and temporal texture of life. In addition, the thesis gives examples of how Beauvoir s literary works contribute to an understanding of the complexity of subjectivity. I use the expression poetics of subjectivity to refer to the systematic relation between Beauvoir s existential and phenomenological notion of subjectivity and her literary works, and to her articulations of a creative mode of using language, especially in the novel. The thesis is divided into five chapters, of which the first three investigate Beauvoir s philosophy of existence at the intersection of the modern traditions of thought that began with René Descartes and Søren Kierkegaard s intuitions about subjectivity. Chapter 1 interprets Beauvoir s notion of ambiguity, as compared to paradox, and argues that both determine her notion of existence. Chapters 2 and 3 investigate the phenomenological side of Beauvoir s philosophy through a study of her response to early French interpretations of transcendental subjectivity, especially in the works of Jean-Paul Sartre and Maurice Merleau-Ponty. My analysis shows that Edmund Husserl s distinction between different levels of subjective experience is central to Beauvoir s understanding of subjectivity and to the different ego concepts she uses. Chapter 4 is a study of Beauvoir s reflections on the expression of subjective thought, and, more specifically, her philosophical conceptions of the metaphysical novel and the autobiography as two modes of indirect communication. Chapter 5, finally, compares two modes of investigating concrete subjectivity; Beauvoir s conceptual study of femininity in Le deuxième sexe and her literary expression of subjectivity in the novel L Invitée. My analysis reveals and explicates Beauvoir s original contribution to a comprehensive understanding of the becoming and paradox of human existence: the fundamental insight that these phenomena are sexed, historically as well as imaginatively.

Systematic Construction of Linear Transform Based Full-Diversity, Rate-One Space-Time Frequency Codes

In this paper, we generalize the existing rate-one space frequency (SF) and space-time frequency (STF) code constructions. The objective of this exercise is to provide a systematic design of full-diversity STF codes with high coding gain. Under this generalization, STF codes are formulated as linear transformations of data. Conditions on these linear transforms are then derived so that the resulting STF codes achieve full diversity and high coding gain with a moderate decoding complexity. Many of these conditions involve channel parameters like delay profile (DP) and temporal correlation. When these quantities are not available at the transmitter, design of codes that exploit full diversity on channels with arbitrary DIP and temporal correlation is considered. Complete characterization of a class of such robust codes is provided and their bit error rate (BER) performance is evaluated. On the other hand, when channel DIP and temporal correlation are available at the transmitter, linear transforms are optimized to maximize the coding gain of full-diversity STF codes. BER performance of such optimized codes is shown to be better than those of existing codes.

A measure of logical complexity of programs

The research in software science has so far been concentrated on three measures of program complexity: (a) software effort; (b) cyclomatic complexity; and (c) program knots. In this paper we propose a measure of the logical complexity of programs in terms of the variable dependency of sequence of computations, inductive effort in writing loops and complexity of data structures. The proposed complexity mensure is described with the aid of a graph which exhibits diagrammatically the dependence of a computation at a node upon the computation of other (earlier) nodes. Complexity measures of several example programs have been computed and the related issues have been discussed. The paper also describes the role played by data structures in deciding the program complexity.

Public-private partnerships in information and communication technology for education

Public-private partnerships (PPPs) have generated a lot of interest from governments around the world for leveraging private sector involvement in developing and sustaining public infrastructure and services. Initially, PPPs were favoured by transport, energy, and other large infrastructure-intensive sectors. More recently, the concept has been expanded to include social sectors such as education.

Multiresolution Area-based Fractal Dimension Estimation of Signals Applied to EEG Data

In this paper, we present an approach to estimate fractal complexity of discrete time signal waveforms based on computation of area bounded by sample points of the signal at different time resolutions. The slope of best straight line fit to the graph of log(A(rk)A / rk(2)) versus log(l/rk) is estimated, where A(rk) is the area computed at different time resolutions and rk time resolutions at which the area have been computed. The slope quantifies complexity of the signal and it is taken as an estimate of the fractal dimension (FD). The proposed approach is used to estimate the fractal dimension of parametric fractal signals with known fractal dimensions and the method has given accurate results. The estimation accuracy of the method is compared with that of Higuchi's and Sevcik's methods. The proposed method has given more accurate results when compared with that of Sevcik's method and the results are comparable to that of the Higuchi's method. The practical application of the complexity measure in detecting change in complexity of signals is discussed using real sleep electroencephalogram recordings from eight different subjects. The FD-based approach has shown good performance in discriminating different stages of sleep.

Signal Characterization using Fractal Dimension

Fractal Dimensions (FD) are popular metrics for characterizing signals. They are used as complexity measuresin signal analysis applications in various fields. However, proper interpretation of such analyses has not been thoroughly addressed. In this paper, we study the effect of various signal properties on FD and interpret results in terms of classical signal processing concepts such as amplitude, frequency,number of harmonics, noise power and signal bandwidth. We have used Higuchi’s method for estimating FDs. This study helps in gaining a better understanding of the FD complexity measure for various signal parameters. Our results indicate that FD is a useful metric in estimating various signal properties. As an application of the FD measure in real world scenario, the FD is used as a feature in discriminating seizures from seizure free intervals in intracranial EEG data recordings and the FD feature has given good discrimination performance.

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.

Soliciting additional concerns in the primary care consultation and the utility of a brief communication intervention to aid solicitation: A qualitative study

Objective To investigate the perspectives of general practitioners (GPs) on the practice of soliciting additional concerns (ACs) and the acceptability and utility of two brief interventions (prompts) designed to aid the solicitation. Methods Eighteen GPs participating in a feasibility randomised controlled trial were interviewed. Interviews were semi-structured and audio-recorded. Data were analysed using a Framework Approach. Results Participants perceived eliciting ACs as important for: reducing the need for multiple visits, identifying serious illness early, and increasing patient and GP satisfaction. GPs found the prompts easy to use and some continued their use after the study had ended to aid time management. Others noted similarities between the intervention and their usual practice. Nevertheless, soliciting ACs in every consultation was not unanimously supported. Conclusion The prompts were acceptable to GPs within a trial context, but there was disagreement as to whether ACs should be solicited routinely. Some GPs considered the intervention to aid their prioritisation efficiency within consultations. Practice implications Some GPs will find prompts which encourage ACs to be solicited early in the consultation enable them to better organise priorities and manage time-limited consultations more effectively.

D-MG Tradeoff and Optimal Codes for a Class of AF and DF Cooperative Communication Protocols

Cooperative relay communication in a fading channel environment under the orthogonal amplify-and-forward (OAF), nonorthogonal and orthogonal selection decode-and-forward (NSDF and OSDF) protocols is considered here. The diversity-multiplexing gain tradeoff (DMT) of the three protocols is determined and DMT-optimal distributed space-time (ST) code constructions are provided. The codes constructed are sphere decodable and in some instances incur minimum possible delay. Included in our results is the perhaps surprising finding that the orthogonal and the nonorthogonal amplify-and-forward (NAF) protocols have identical DMT when the time durations of the broadcast and cooperative phases are optimally chosen to suit the respective protocol. Moreover our code construction for the OAF protocol incurs less delay. Two variants of the NSDF protocol are considered: fixed-NSDF and variable-NSDF protocol. In the variable-NSDF protocol, the fraction of time occupied by the broadcast phase is allowed to vary with multiplexing gain. The variable-NSDF protocol is shown to improve on the DMT of the best previously known static protocol when the number of relays is greater than two. Also included is a DMT optimal code construction for the NAF protocol.