A study of the generalised max–min fair rate allocation for ABR control in ATM

In the rate-based flow control for ATM Available Bit Rate service, fairness is an important requirement, i.e. each flow should be allocated a fair share of the available bandwidth in the network. Max–min fairness, which is widely adopted in ATM, is appropriate only when the minimum cell rates (MCRs) of the flows are zero or neglected. Generalised max–min (GMM) fairness extends the principle of the max–min fairness to accommodate MCR. In this paper, we will discuss the formulation of the GMM fair rate allocation, propose a centralised algorithm, analyse its bottleneck structure and develop an efficient distributed explicit rate allocation algorithm to achieve the GMM fairness in an ATM network. The study in this paper addresses certain theoretical and practical issues of the GMM fair rate allocation.

Fair flow control of ABR service by per-VC virtual queuing

In this paper, a rate-based flow control scheme based upon per-VC virtual queuing is proposed for the Available Bit Rate (ABR) service in ATM. In this scheme, each VC in a shared buffer is assigned a virtual queue, which is a counter. To achieve a specific kind of fairness, an appropriate scheduler is applied to the virtual queues. Each VC's bottleneck rate (fair share) is derived from its virtual cell departure rate. This approach of deriving a VC's fair share is simple and accurate. By controlling each VC with respect to its virtual queue and queue build-up in the shared buffer, network congestion is avoided. The principle of the control scheme is first illustrated by max–min flow control, which is realised by scheduling the virtual queues in round-robin. Further application of the control scheme is demonstrated with the achievement of weighted fairness through weighted round robin scheduling. Simulation results show that with a simple computation, the proposed scheme achieves the desired fairness exactly and controls network congestion effectively.

Fabrication of osteochondral scaffolds with stereolithography

The osteochondral defect is a classical model for a multiple-tissue problem[1]. Tissue engineering of either bone or cartilage imposes different demands on a scaffold concerning porosity, pore size and interconnectivity. Furthermore, local release of tissue-specific growth factors necessitates a tailored architecture. For the fabrication of an osteochondral scaffold with region specific architecture, an advanced technique is required. Stereolithography is a rapid prototyping technique that allows for the creation of such 3D polymer objects with well-defined architecture. Its working principle is the partial irradiation of a resin, causing a liquid-solid transition. By irradiating this resin by a computer-driven light source, a solid 3D object is constructed layer by layer. To make biodegradable polymers applicable in stereolithography, low-molecular weight polymers have to be functionalised with double bonds to enable photo-initiated crosslinking.

Identity fraud and torrens - minimising the risks and allocating the loss to achieve a sustainable system

Immediate indefeasibility is the cornerstone of the Torrens system of land registration. However, when combined with the apparent ease in which forged mortgages become registered, the operation of this doctrine can come into question. This article seeks to argue that, rather than question indefeasibility, the focus should be on the verification of identity of parties to land transactions. Whilst no system can ever be infallible, it is suggested that by correctly imposing the responsibility for identity verification on the appropriate individual, the Torrens system can retain immediate indefeasibility as its paramount principle, yet achieve the optimum level of fairness in terms of allocation of responsibility and loss. With the dawn of a new era of electronic conveyancing about to begin, the framework suggested here provides a model for minimising the risks of forged mortgages and appropriately allocating the loss.

Reverse immigration

This book (256 pages, written in Korean) is a critical essay that reviews, questions, and criticises Korean and Eastern immigrants’ thinking and behaviour styles in Australia from their cultural perspectives, and discuss and proposes a creative cultural dimension for their better life in a multicultural context. Multiculturalism is not supportive of Eastern cultures because of individualistic collection of cultures, while transculturalism facilitates nurture of their culture in a community-oriented way within multicultural circumstances. Korean and Eastern immigrants, sharing oriental cultural systems and values, should approach to the Australian multicultural context with transculturalism which allows creating new cultural values in collaboration with and by participation into local communities. ------------------------------------------------------------ Many Eastern immigrants live in their own ethnic communities without or less interacting with Australian (communities). The author defines this phenomenon as “reverse immigration”. Reverse immigration refers to re-immigrating to their ethnic community in Australia or to their birth country despite they did not anticipate that this would happen to them before immigration to Australia. The author argues that Easterners’ collectivistic culture often devalues individuality and vice versa. Cultural clash between West and East often forces the immigrants to choose reverse immigration because of their lack of understanding of Western culture and their cultural characteristics such as low individuality, high power distance, and high uncertainty avoidance. For example, a vague boundary between individualist and collectivist in a collectivistic context (within their ethnic group) often leads to maladjustment to local communities and enhancement of cultural conservatism. The author proposes that the cultural clash can be overcome by cross-cultural activities named “transculturalism”. To Eastern immigrants, transculturalism can be achieved by acculturation of their two predominant cultures, the third-person perspective and generalised others. In a multicultural context, the former refers to the ability to share another person's feelings and emotions as if they were your own, and the latter does the ability to manage community and public expectations. When both cultural values are used for quality interactions between East and West, they allow Eastern immigrants to be more creative and critical and Australian to be more socially inclusive and culturally tolerant. With these discussions, the author discusses cultural differences throughout the book with four topics (chapters) and proposes transculturalism as a solution to the reverse immigration. ------------------------------------------------------------ Chapter 1 criticises Koreans’ attitudes and methods towards learning English that is less pragmatic and practical, but more likely to be a scholarly study. The author explains that Koreans’ non-pragmatic towards learning English has been firmly built based on their traditional systems and values that Koreans view English as a discipline and an aim of academic achievements rather than a means of communication. Within their cultural context, English can be perceived as more than a language, but something like vastly superior to their language and culture. Their collectivistic culture regards English as an unreachable and heterogeneous one that may threaten their cultural identity, so that “scholarly studying” is only the way to achieve (not learn) it. This discourages the immigrants to engage and involve in daily dialogues by “using” English as a second language. The author further advises the readers to be aware of Eastern collectivistic culture in communication and interaction that sometimes completely reverses private and public topics in a Western context. This leads them to feel that they have no content to talk to natives. ------------------------------------------------------------ Chapter 2 compares between Korea and Australia in terms of their educational systems and values, and proposes how Eastern overseas students can achieve critical and creative thinking within a Western educational setting. Interestingly, this chapter includes an explanation of why Eastern overseas students easily fail assessments including essay writing, oral presentations and discussions. One of the reasons the author explains is that Eastern students are not familiar to criticise others and think creatively, especially when they recognise that their words and ideas may harm the collectivistic harmony. Western educational systems focuses on enhancement of individuality such as self-confidence, self-esteem, and self-expression, while Eastern educational systems foster group-oriented values such as interpersonal relationship, and strong moral and spiritual values. Yet, the author argues that the collectivistic approach to criticism and creativity is often more critical and creative than Western individuals when they know what they are supposed to do for a group (or a community). Therefore, Eastern students need to think their cultural merits and demerits by using an individual perspective rather than generalised others’ perspective. The latter often discourages individual participation in a community, and the generalised others in a Western culture is weaker than Eastern. Furthermore, Western educational systems do not educate students to transform (loose) their individuality to fit into a group or a community. Rather they cultivate individuality for community prosperity. ------------------------------------------------------------ Chapter 3 introduces various cases of reverse immigration in workplaces that many immigrants return to their country or their ethnic community after many trials for acculturation. Reverse immigration is unexpected and not planned before immigration, so that its emotional embarrassment increases such severe social loneliness. Most Eastern immigrant workers have tried to adjust themselves in this new cultural environment at the early stages of immigration. However, their cultural features of collectivism, high power distance, high uncertainty avoidance, and long-term oriented cultures suppress individual initiative and eliminate the space for experiments in ways of acculturation. The author argues that returning to their ethnic community (physically and psychologically) leads to two significant problems: their distorted parenting and becoming more conservatives. The former leads the first generation of immigrants to pressure their children to pursue extrinsic or materialist values, such as financial success, fame and physical appearance, rather than on intrinsic values, while the latter refers to their isolated conservative characters because of their remoteness from the changes of their own country. The author also warns that their ethnic and religious groups actively strengthens immigrants’ social loneliness and systematically discourages immigrants’ interests and desire to be involving into local communities. The ethnic communities and leaders have not been interacting with Australian local communities and, as a result, are eager to conserve outdated cultural systems values. Even they have a tendency to weed out those people who wish to settle down within Australian local communities. They believe that those people can threaten their community’s survival and continuity. ------------------------------------------------------------ Chapter 4 titled multiculturalism argues that Korean and Eastern immigrants should more precisely understand Australia as a multicultural society in a way of collaboratively creating new cultural values. The author introduces multiculturalism with its definitions and history in Australia and argues the limitations of multiculturalism from an Easterner’s perspective. With well known tragedies of the second generations of U.S. immigrants, Cho Seung-Hui, a university student, massacred 32 people on the Virginia Tech before committing suicide and Hidal Hassan, an Army psychiatrist, killed 13 people at Fort Hood and the responses of ethnic community, the author explains that their mental illness may be derived from their parents’ (or ethnic group) culturally isolated attitude and socially static viewpoint of U.S. (Western system and values). The author insists that multiculturalism may restrict Eastern immigrants’ engagement and involvement in local communities. Multiculturalism has been systematically and historically developed based on Western systems and cultural values. In other words, multiculturalism requires high self-confidence and self-esteem that Eastern immigrants less prioritise them. It has been generally known that Easterners put more weight on human relationship than Westerners, but the author claims that this is not true. Within an individualistic culture, Westerners are more interested in building person-to-person connections and relationships. While Easterners are more interested in how individuals can achieve a sense of belonging within a group and a community. Therefore, multiculturalism is an ideology which forces Eastern immigrants to discard their strong desire to be part of a group and does not give a sense of belonging. In a consequence, the author advises that Eastern immigrants should aim towards “transculturalism” which allows them to actively participate in and contribute to their multicultural community. Transculturalism does not ask Easterners to discard their cultural values, but enables them to be a collectivistic individualist (a community leader) who is capable of developing new cultural values in a more creative and productive way. Furthermore, transculturalism encourages Western Australians in a multicultural context to collaborate with ethnic minorities to build a better community.

The application of public asset management in Indonesian local government : a case study in South Sulawesi Province

Purpose To identify the challenges faced by local government in Indonesia when adopting a Public Asset Management Framework. Design A Case Study in South Sulawesi Provincial Government was used as the approach to achieving the research objective. The case study involved two data collection techniques - interviews and document analysis. Findings The result of the study indicates there are significant challenges that the Indonesian local government need to manage when adopting a public asset management framework. Those challenges are: absence of an institutional and legal framework to support the asset management application; non-profit principle of public assets; multiple jurisdictions involved in the public asset management processes; the complexity of local government objectives; unavailability of data for managing public property; and limited human resources. Research Limitation This research is limited to one case study. It is a preliminary study from larger research that uses multiple case studies. The main research also investigates opportunities for local government by adopting and implementing public asset management. Originality/Value Findings from this study provide useful input for the policy makers, academics and asset management practitioners in Indonesia to establish a public asset management framework resulting in efficient and effective organizations, as well as an increase of public services quality. This study has a potential application for other developing countries.

Law autonomy and advance directives

The principle of autonomy underpins legal regulation of advance directives that refuse life-sustaining medical treatment. The primacy of autonomy in this domain is recognised expressly in the case law, through judicial pronouncement, and implicitly in most Australian jurisdictions, through enactment into statute of the right to make an advance directive. This article seeks to justify autonomy as an appropriate principle for regulating advance directives and relies on three arguments: the necessity of autonomy in a liberal democracy; the primacy of autonomy in medical ethics discourse; and the uncontested importance of autonomy in the law on contemporaneous refusal of medical treatment. This article also responds to key criticisms that autonomy is not an appropriate organising principle to underpin legal regulation of advance directives.

Legal responses to climate change

The challenges of climate change pose problems requiring new and innovative legal responses by legal practitioners, government officials and corporate officers. This book addresses a broad range of topic areas where climate change has impact and systematically analyses the key legal responses to climate change, both at the international level and within Australia at federal, State and local levels. In particular, it critically examines: •the rights, duties and market mechanisms established under the international climate change regime •the effect of climate change policies on the implementation of environmental and planning laws •new regimes for the implementation of renewable energy and energy efficiency initiatives •legal frameworks for the implementation of biological and geological sequestration projects (including forest projects and carbon rights); and •legal principles for the design of an effective carbon trading scheme for Australia It also considers the role of the common law including: •the likely response of the law of torts to emerging forms of climate change harm; and •potential liabilities for professionals who must take climate change into account in their decision-making and advice

Interventions for preventing and managing aggressive patients admitted to an acute hospital setting: A systematic review

Background: Violence in health care has been widely reported and health care workers, particularly nurses in acute care settings, are ill-equipped to manage patients who exhibit aggressive traits. Aim: The aim of this systematic review was to establish best practice in the prevention and management of aggressive behaviours in patients admitted to acute hospital settings. Data Sources: An extensive search of the major databases was conducted from 1990 to 2007. The search included published and unpublished studies and papers in English. Review Methods: This review considered any quantitative research study design that evaluated the effectiveness of interventions in the prevention and management of patients who exhibit aggressive behaviours in an acute hospital setting. Each included study was quality assessed by two independent reviewers and data were extracted using the relevant tools developed by the Joanna Briggs Institute. Results: Ten studies met the inclusion criteria and were included in the review. The evidence identified from the studies includes: the benefit of education and training of acute care nurses in aggression management techniques; use of “as required” medications is effective in minimising harm to patients and staff; and that specific interventions such as physical restraint may play a role in managing aggressive behaviours from patients in the acute care setting. Conclusions: This review makes several recommendations for the prevention and management of aggressive behaviours in acute hospital patients. However, due to the lack of high-quality studies conducted in the acute care setting there is huge scope for future research in this area.

Dynamics of pattern writing and erasure in photorefractive lithium niobate for data storage applications

The present rate of technological advance continues to place significant demands on data storage devices. The sheer amount of digital data being generated each year along with consumer expectations, fuels these demands. At present, most digital data is stored magnetically, in the form of hard disk drives or on magnetic tape. The increase in areal density (AD) of magnetic hard disk drives over the past 50 years has been of the order of 100 million times, and current devices are storing data at ADs of the order of hundreds of gigabits per square inch. However, it has been known for some time that the progress in this form of data storage is approaching fundamental limits. The main limitation relates to the lower size limit that an individual bit can have for stable storage. Various techniques for overcoming these fundamental limits are currently the focus of considerable research effort. Most attempt to improve current data storage methods, or modify these slightly for higher density storage. Alternatively, three dimensional optical data storage is a promising field for the information storage needs of the future, offering very high density, high speed memory. There are two ways in which data may be recorded in a three dimensional optical medium; either bit-by-bit (similar in principle to an optical disc medium such as CD or DVD) or by using pages of bit data. Bit-by-bit techniques for three dimensional storage offer high density but are inherently slow due to the serial nature of data access. Page-based techniques, where a two-dimensional page of data bits is written in one write operation, can offer significantly higher data rates, due to their parallel nature. Holographic Data Storage (HDS) is one such page-oriented optical memory technique. This field of research has been active for several decades, but with few commercial products presently available. Another page-oriented optical memory technique involves recording pages of data as phase masks in a photorefractive medium. A photorefractive material is one by which the refractive index can be modified by light of the appropriate wavelength and intensity, and this property can be used to store information in these materials. In phase mask storage, two dimensional pages of data are recorded into a photorefractive crystal, as refractive index changes in the medium. A low-intensity readout beam propagating through the medium will have its intensity profile modified by these refractive index changes and a CCD camera can be used to monitor the readout beam, and thus read the stored data. The main aim of this research was to investigate data storage using phase masks in the photorefractive crystal, lithium niobate (LiNbO3). Firstly the experimental methods for storing the two dimensional pages of data (a set of vertical stripes of varying lengths) in the medium are presented. The laser beam used for writing, whose intensity profile is modified by an amplitudemask which contains a pattern of the information to be stored, illuminates the lithium niobate crystal and the photorefractive effect causes the patterns to be stored as refractive index changes in the medium. These patterns are read out non-destructively using a low intensity probe beam and a CCD camera. A common complication of information storage in photorefractive crystals is the issue of destructive readout. This is a problem particularly for holographic data storage, where the readout beam should be at the same wavelength as the beam used for writing. Since the charge carriers in the medium are still sensitive to the read light field, the readout beam erases the stored information. A method to avoid this is by using thermal fixing. Here the photorefractive medium is heated to temperatures above 150�C; this process forms an ionic grating in the medium. This ionic grating is insensitive to the readout beam and therefore the information is not erased during readout. A non-contact method for determining temperature change in a lithium niobate crystal is presented in this thesis. The temperature-dependent birefringent properties of the medium cause intensity oscillations to be observed for a beam propagating through the medium during a change in temperature. It is shown that each oscillation corresponds to a particular temperature change, and by counting the number of oscillations observed, the temperature change of the medium can be deduced. The presented technique for measuring temperature change could easily be applied to a situation where thermal fixing of data in a photorefractive medium is required. Furthermore, by using an expanded beam and monitoring the intensity oscillations over a wide region, it is shown that the temperature in various locations of the crystal can be monitored simultaneously. This technique could be used to deduce temperature gradients in the medium. It is shown that the three dimensional nature of the recording medium causes interesting degradation effects to occur when the patterns are written for a longer-than-optimal time. This degradation results in the splitting of the vertical stripes in the data pattern, and for long writing exposure times this process can result in the complete deterioration of the information in the medium. It is shown in that simply by using incoherent illumination, the original pattern can be recovered from the degraded state. The reason for the recovery is that the refractive index changes causing the degradation are of a smaller magnitude since they are induced by the write field components scattered from the written structures. During incoherent erasure, the lower magnitude refractive index changes are neutralised first, allowing the original pattern to be recovered. The degradation process is shown to be reversed during the recovery process, and a simple relationship is found relating the time at which particular features appear during degradation and recovery. A further outcome of this work is that the minimum stripe width of 30 ìm is required for accurate storage and recovery of the information in the medium, any size smaller than this results in incomplete recovery. The degradation and recovery process could be applied to an application in image scrambling or cryptography for optical information storage. A two dimensional numerical model based on the finite-difference beam propagation method (FD-BPM) is presented and used to gain insight into the pattern storage process. The model shows that the degradation of the patterns is due to the complicated path taken by the write beam as it propagates through the crystal, and in particular the scattering of this beam from the induced refractive index structures in the medium. The model indicates that the highest quality pattern storage would be achieved with a thin 0.5 mm medium; however this type of medium would also remove the degradation property of the patterns and the subsequent recovery process. To overcome the simplistic treatment of the refractive index change in the FD-BPM model, a fully three dimensional photorefractive model developed by Devaux is presented. This model shows significant insight into the pattern storage, particularly for the degradation and recovery process, and confirms the theory that the recovery of the degraded patterns is possible since the refractive index changes responsible for the degradation are of a smaller magnitude. Finally, detailed analysis of the pattern formation and degradation dynamics for periodic patterns of various periodicities is presented. It is shown that stripe widths in the write beam of greater than 150 ìm result in the formation of different types of refractive index changes, compared with the stripes of smaller widths. As a result, it is shown that the pattern storage method discussed in this thesis has an upper feature size limit of 150 ìm, for accurate and reliable pattern storage.

Estimating the cost of health care–associated infections : mind your p’s and q’s

Monetary valuations of the economic cost of health care–associated infections (HAIs) are important for decision making and should be estimated accurately. Erroneously high estimates of costs, designed to jolt decision makers into action, may do more harm than good in the struggle to attract funding for infection control. Expectations among policy makers might be raised, and then they are disappointed when the reduction in the number of HAIs does not yield the anticipated cost saving. For this article, we critically review the field and discuss 3 questions. Why measure the cost of an HAI? What outcome should be used to measure the cost of an HAI? What is the best method for making this measurement? The aim is to encourage researchers to collect and then disseminate information that accurately guides decisions about the economic value of expanding or changing current infection control activities.

Years 2 to 6 students' ability to generalise : models, representations and theory for teaching and learning

Over the last three years, in our Early Algebra Thinking Project, we have been studying Years 3 to 5 students’ ability to generalise in a variety of situations, namely, compensation principles in computation, the balance principle in equivalence and equations, change and inverse change rules with function machines, and pattern rules with growing patterns. In these studies, we have attempted to involve a variety of models and representations and to build students’ abilities to switch between them (in line with the theories of Dreyfus, 1991, and Duval, 1999). The results have shown the negative effect of closure on generalisation in symbolic representations, the predominance of single variance generalisation over covariant generalisation in tabular representations, and the reduced ability to readily identify commonalities and relationships in enactive and iconic representations. This chapter uses the results to explore the interrelation between generalisation and verbal and visual comprehension of context. The studies evidence the importance of understanding and communicating aspects of representational forms which allowed commonalities to be seen across or between representations. Finally the chapter explores the implications of the studies for a theory that describes a growth in integration of models and representations that leads to generalisation.

Creating an effective prevention curriculum to reduce transport risks and injuries

Adolescent injury is a significant health concern and can be a result of the adolescents engagement in transport-related behaviours. There is however significant planning and formative research needed to inform prevention programme design. This presentation reports on the development and evaluation of a curriculum programme that was shown to be effective in reducing transport-related risks and injuries. Early adolescents report injuries resulting from a number of transport-related behaviours including those associated with riding a bicycle, a motorcycle, and as a passenger (survey of 209 Year 9 students). In focus groups, students (n=30) were able to describe the context of transport risks and injuries. Such information provided evidence of the need for an intervention and ecologically valid data on which to base programme design including insights into the language, culture and development of adolescents and their experiences with transport risks. Additional information about teaching practices and implementation issues were explored in interviews with 13 teachers. A psychological theory was selected to operationalise the design of the programmes that drew on such preparatory data. The programme, Skills for Preventing Injury in Youth was evaluated with 197 participating and 137 control students (13–14 year olds). Results showed a significant difference between the intervention and control groups from baseline to 6-month follow-up in a number of transport-related risk behaviours and transport-related injuries. The programme thus demonstrated potential in reduce early adolescents transport risk behaviours and associated harm. Discussion will involve the implications of the development research process in designing road safety interventions.

Implementation results of efficient trajectories on a testbed AUV

In this paper we consider the implementation of time and energy efficient trajectories onto a test-bed autonomous underwater vehicle. The trajectories are losely connected to the results of the application of the maximum principle to the controlled mechanical system. We use a numerical algorithm to compute efficient trajectories designed using geometric control theory to optimize a given cost function. Experimental results are shown for the time minimization problem.

Hydrodynamic and thruster model validation for autonomous underwater vehicles

From Pontryagin’s Maximum Principle to the Duke Kahanamoku Aquatic Complex; we develop the theory and generate implementable time efficient trajectories for a test-bed autonomous underwater vehicle (AUV). This paper is the beginning of the journey from theory to implementation. We begin by considering pure motion trajectories and move into a rectangular trajectory which is a concatenation of pure surge and pure sway. These trajectories are tested using our numerical model and demonstrated by our AUV in the pool. In this paper we demonstrate that the above motions are realizable through our method, and we gain confidence in our numerical model. We conclude that using our current techniques, implementation of time efficient trajectories is likely to succeed.