Genetic algorithms with applications in wireless communications

Genetic algorithms (GAs) are known to locate the global optimal solution provided sufficient population and/or generation is used. Practically, a near-optimal satisfactory result can be found by Gas with a limited number of generations. In wireless communications, the exhaustive searching approach is widely applied to many techniques, such as maximum likelihood decoding (MLD) and distance spectrum (DS) techniques. The complexity of the exhaustive searching approach in the MLD or the DS technique is exponential in the number of transmit antennas and the size of the signal constellation for the multiple-input multiple-output (MIMO) communication systems. If a large number of antennas and a large size of signal constellations, e.g. PSK and QAM, are employed in the MIMO systems, the exhaustive searching approach becomes impractical and time consuming. In this paper, the GAs are applied to the MLD and DS techniques to provide a near-optimal performance with a reduced computational complexity for the MIMO systems. Two different GA-based efficient searching approaches are proposed for the MLD and DS techniques, respectively. The first proposed approach is based on a GA with sharing function method, which is employed to locate the multiple solutions of the distance spectrum for the Space-time Trellis Coded Orthogonal Frequency Division Multiplexing (STTC-OFDM) systems. The second approach is the GA-based MLD that attempts to find the closest point to the transmitted signal. The proposed approach can return a satisfactory result with a good initial signal vector provided to the GA. Through simulation results, it is shown that the proposed GA-based efficient searching approaches can achieve near-optimal performance, but with a lower searching complexity comparing with the original MLD and DS techniques for the MIMO systems.

Asymmetric Bragg mirrors for the reduction of emission wavelength dependence on the viewing angle in organic microcavity light emitting diodes

Organic microcavity light emitting diodes typically exhibit a blue shift of the emitting wavelength with increasing viewing angle. While the wavelength shift can be reduced with the appropriate choice of organic materials and metal mirrors, for further reduction of the emission wavelength shift it is necessary to consider a mirror whose phase shift can partly compensate the effect of the change of optical path within the cavity. In this work, we used a genetic algorithm (GA) to design an asymmetric Bragg mirror in order to minimize the emission wavelength shift with viewing angle. Based on simulation results, the use of asymmetric Bragg mirrors represents a promising way to reduce the emission wavelength shift. Detailed comparison between GA optimized and conventional Bragg mirrors in terms of resonant wavelength dependence on the viewing angle, spectral narrowing, and brightness enhancement is given. (C) 2004 Elsevier B.V. All rights reserved.

Women are silver, women are diamonds: Conflicting images of women in the Cambodian print

This paper examines 116 articles related to sexual and reproductive health translated into English from the Khmer press from April 1997 to February 2004. These excerpts were found in The Mirror, a publication of the non-governmental organisation Open Forum of Cambodia, which collates Grid reviews all issues of the Khmer press on a weekly basis. Five major themes were identified: the politics of women's health, government regulation and control, the sex industry in Cambodia, rape, and the HIV epidemic. Discourse analysis of these articles in the context of other sources and experience allows a gendered exploration of the reporting of sexual and reproductive health and rights issues in Cambodia by the Khmer print media. The reports explore the contested political empowerment of women in this strongly hierarchical society, and the mechanisms used to regulate and control sexual activity. The expanding sex industry and associated sexual trafficking ore reported, together with the corruption of legal structures designed to regulate health systems and protect women and children from sexual exploitation and rope. The growing problem of AIDS and successes in reducing HIV transmission through the collaboration of sex workers in the 100% condom use policy is documented, and the tensions implicit in G Cultural representation of women that both protects and constrains women ore explored. (C) 2004 Reproductive Health Matters. All rights reserved.

IS/IT outsourcing practices of small- and medium-sized manufacturers

Firms began outsourcing information system functions soon after the inception of electronic computing. Extant research has concentrated on large organizations and large-valued outsourcing contracts from a variety of different industries. Smaller-sized firms are inherently different from their large counterparts. These differences between small and large firms could lead to different information technology/information system (IT/IS) items being outsourced and different outsourcing agreements governing these arrangements. This research explores and examines the outsourcing practices of very small through to medium-sized manufacturing organizations. The in-depth case studies not only explored the extent to which different firms engaged in outsourcing but also the nuances of their outsourcing arrangements. The results reveal that all six firms tended to outsource the same sorts of functions. Some definite differences existed, however, in the strategies adopted in relation to the functions they outsourced. These differences arose for a variety of reasons, including size, locality, and holding company influences. The very small and small manufacturing firms tended to make outsourcing purchases on an ad hoc basis with little reliance on legal advice. In contrast, the medium-sized firms often used a more planned initiative and sought legal advice more often. Interestingly, not one of the six firms outsourced any of their transaction processing. These findings now give very small, small-, and medium-sized manufacturing firms the opportunity to compare their practices against other firms of similar size.

A perspective on Australia's national medicines policy

There is international interest in Australia's health care system for prescription medicines. The issue is particularly topical in Canada with the debate following publication of the Romanow Report into the future of health care in Canada. This Report recommended a new National Drug Agency. Australia has a National Medicines Policy with four arms-quality, safety and efficacy of medicines; equity of access; a viable and responsible pharmaceutical industry; quality use of medicines. The four arms of the Policy are interlinked and interdependent for optimal functioning. In this paper, an overview of how the prescription drug system in Australia works is presented. The manuscript focuses upon specific aspects of the Policy, describing how it functions and some of the processes integral to success, from the viewpoint of the author. The discussion includes some of the advantages of Australia's system for pharmaceuticals as well as some of the problems, as these present opportunities for development and change

A prospective multicentre study of pharmacist initiated changes to drug therapy and patient management in acute care government funded hospitals

Aims To determine the cost savings of pharmacist initiated changes to hospitalized patients' drug therapy or management in eight major acute care government funded teaching hospitals in Australia. Methods This was a prospective study performed in eight hospitals examining resource implications of pharmacists' interventions assessed by an independent clinical panel. Pharmacists providing clinical services to inpatients recorded details of interventions, defined as any action that directly resulted in a change to patient management or therapy. An independent clinical review panel, convened at each participating centre, confirmed or rejected the clinical pharmacist's assessment of the impact on length of stay (LOS), readmission probability, medical procedures and laboratory monitoring and quantified the resultant changes, which were then costed. Results A total of 1399 interventions were documented. Eight hundred and thirty-five interventions impacted on drug costs alone. Five hundred and eleven interventions were evaluated by the independent panels with three quarters of these confirmed as having an impact on one or more of: length of stay, readmission probability, medical procedures or laboratory monitoring. There were 96 interventions deemed by the independent panels to have reduced LOS and 156 reduced the potential for readmission. The calculated savings was $263 221 for the eight hospitals during the period of the study. This included $150 307 for length of stay reduction, $111 848 for readmission reduction. Conclusions The annualized cost savings relating to length of stay, readmission, drugs, medical procedures and laboratory monitoring as a result of clinical pharmacist initiated changes to hospitalized patient management or therapy was $4 444 794 for eight major acute care government funded teaching hospitals in Australia.

The effect of bandwidth on the quality of transmitted pediatric echocardiograms

Background: Remote access to pediatric cardiology diagnostic services is enabled by real-time transmission of echocardiographic images. Several transmission bandwidths have been used but there has been little analysis of image quality provided by different bandwidths. We designed a study of the quality of transmitted images at various bandwidths. Methods: Two echocardiographers viewed randomly a series of 13 recorded pediatric echocardiographic images either directly or after transmission using 1 of 4 bandwidths: 256; 384; 512; or 768 kbps. An image clarity scoring scale was used to assess image quality of cardiac structures. Results: Measurable differences were found in image quality with different transmission bandwidths; 512 kbps was the minimum for consistently clear imaging of all cardiac structures examined. Conclusion: Bandwidth greater than 512 kbps confers sharper images subjectively although this could not be quantified by our methods.

Building family/general practice research capacity

To promote the range of interventions for building family/general practice (family medicine) research capacity, we describe successful international examples. Such examples of interventions that build research capacity focus on diseases and illness research, as well as process research; monitor the output of research in family/general practice (family medicine); increase the number of family medicine research journals; encourage and enable research skills acquisition (including making it part of professional training); strengthen the academic base; and promote research networks and collaborations. The responsibility for these interventions lies with the government, colleges and academies, and universities. There are exciting and varied methods of building research capacity in family medicine.

A feasibility study of email communication between the patient's family and the specialist burns team

We investigated whether the parents of burns patients could capture suitable clinical images with a digital camera and add the necessary text information to enable the paediatric burns team to provide follow-up care via email. Four families were involved in the study, each of whom sent regular email consultations for six months. The results were very encouraging. The burns team felt confident that the clinical information in 30 of the 32 email messages (94%) they received was accurate, although in I I of these 30 cases (37%) they stated that there was room for improvement (the quality was nonetheless adequate for clinical decision making). The study also showed that low-resolution images (average size 37 kByte) were satisfactory for diagnosis. Families were able to participate in the service without intensive training and support. The user survey showed that all four families found it easy and convenient to take the digital photographs and to participate in the study. The results suggest that the technique has potential as a low-cost telemedicine service in burns follow-up, and that it requires only modest investment in equipment, training and support.