Lower partial moment and information entropy-based dynamic electricity purchasing strategy

In the electricity market environment, load-serving entities (LSEs) will inevitably face risks in purchasing electricity because there are a plethora of uncertainties involved. To maximize profits and minimize risks, LSEs need to develop an optimal strategy to reasonably allocate the purchased electricity amount in different electricity markets such as the spot market, bilateral contract market, and options market. Because risks originate from uncertainties, an approach is presented to address the risk evaluation problem by the combined use of the lower partial moment and information entropy (LPME). The lower partial moment is used to measure the amount and probability of the loss, whereas the information entropy is used to represent the uncertainty of the loss. Electricity purchasing is a repeated procedure; therefore, the model presented represents a dynamic strategy. Under the chance-constrained programming framework, the developed optimization model minimizes the risk of the electricity purchasing portfolio in different markets because the actual profit of the LSE concerned is not less than the specified target under a required confidence level. Then, the particle swarm optimization (PSO) algorithm is employed to solve the optimization model. Finally, a sample example is used to illustrate the basic features of the developed model and method.

Detection of dynamic primary user with cooperative spectrum sensing

In this paper we demonstrate that existing cooperative spectrum sensing formulated for static primary users cannot accurately detect dynamic primary users regardless of the information fusion method. Performance error occurs as the sensing parameters calculated by the conventional detector result in sensing performance that violates the sensing requirements. Furthermore, the error is accumulated and compounded by the number of cooperating nodes. To address this limitation, we design and implement the duty cycle detection model for the context of cooperative spectrum sensing to accurately calculate the sensing parameters that satisfy the sensing requirements. We show that longer sensing duration is required to compensate for dynamic primary user traffic.

Cutting the Gordian knot of futility : a case for law reform on unilateral withholding and withdrawal of potentially life-sustaining treatment

In this paper, we propose law reform with respect to the unilateral withholding or withdrawal of potentially life-sustaining treatment in Australia and New Zealand. That is, where a doctor withholds or withdraws potentially life-sustaining treatment without consent from a patient or a patient’s substitute decision-maker (where the patient lacks capacity), or authorisation from a court or tribunal, or by operation of a statute or justifiable government or institutional policy. Our proposal is grounded in the core values that do (or should) underpin a regulatory framework on an issue such as this; these values are drawn from existing commitments made by Australia and New Zealand through legislation, the common law, and conventions and treaties. It is also grounded in a critical review of the law on unilateral withholding and withdrawal as well as the legal context within which this issue sits in Australasia. We argue that the current law is inconsistent with the core values and develop a proposal for a legal response to this issue that more closely aligns with the core values it is supposed to serve.

Withholding and withdrawing life-sustaining medical treatment

• At common law, a competent adult can refuse life-sustaining medical treatment, either contemporaneously or through an advance directive which will operate at a later time when the adult’s capacity is lost. • Legislation in most Australian jurisdictions also provides for a competent adult to complete an advance directive that refuses life-sustaining medical treatment. • At common law, a court exercising its parens patriae jurisdiction can consent to, or authorise, the withdrawal or withholding of life-sustaining medical treatment from an adult or child who lacks capacity if that is in the best interests of the person. A court may also declare that the withholding or withdrawal of treatment is lawful. • Guardianship legislation in all jurisdictions allows a substitute decision-maker, in an appropriate case, to refuse life-sustaining medical treatment for an adult who lacks capacity. • In terms of children, a parent may refuse life-sustaining medical treatment for his or her child if it is in the child’s best interests. • While a refusal of life-sustaining medical treatment by a competent child may be valid, this decision can be overturned by a court. • At common law and generally under guardianship statutes, demand for futile treatment need not be complied with by doctors.

Compatibility of stormwater treatment performance data between different geographical areas

Using a case study approach, this paper presents a robust methodology for assessing the compatibility of stormwater treatment performance data between two geographical regions in relation to a treatment system. The desktop analysis compared data derived from a field study undertaken in Florida, USA, with South East Queensland (SEQ) rainfall and pollutant characteristics. The analysis was based on the hypothesis that when transposing treatment performance information from one geographical region to another, detailed assessment of specific rainfall and stormwater quality parameters is required. Accordingly, characteristics of measured rainfall events and stormwater quality in the Florida study were compared with typical characteristics for SEQ. Rainfall events monitored in the Florida study were found to be similar to events that occur in SEQ in terms of their primary characteristics of depth, duration and intensity. Similarities in total suspended solids (TSS) and total nitrogen (TN) concentration ranges for Florida and SEQ suggest that TSS and TN removal performances would not be very different if the treatment system is installed in SEQ. However, further investigations are needed to evaluate the treatment performance of total phosphorus (TP). The methodology presented also allows comparison of other water quality parameters.

A gray-box neural network-based model identification and fault estimation scheme for nonlinear dynamic systems

A novel gray-box neural network model (GBNNM), including multi-layer perception (MLP) neural network (NN) and integrators, is proposed for a model identification and fault estimation (MIFE) scheme. With the GBNNM, both the nonlinearity and dynamics of a class of nonlinear dynamic systems can be approximated. Unlike previous NN-based model identification methods, the GBNNM directly inherits system dynamics and separately models system nonlinearities. This model corresponds well with the object system and is easy to build. The GBNNM is embedded online as a normal model reference to obtain the quantitative residual between the object system output and the GBNNM output. This residual can accurately indicate the fault offset value, so it is suitable for differing fault severities. To further estimate the fault parameters (FPs), an improved extended state observer (ESO) using the same NNs (IESONN) from the GBNNM is proposed to avoid requiring the knowledge of ESO nonlinearity. Then, the proposed MIFE scheme is applied for reaction wheels (RW) in a satellite attitude control system (SACS). The scheme using the GBNNM is compared with other NNs in the same fault scenario, and several partial loss of effect (LOE) faults with different severities are considered to validate the effectiveness of the FP estimation and its superiority.

Regional trade-offs between mine water and energy use : a water treatment case study

The mining industry faces concurrent pressures of reducing water use, energy consumption and greenhouse gas (GHG) emissions in coming years. However, the interactions between water and energy use, as well as GHG e missions have largely been neglected in modelling studies to date. In addition, investigations tend to focus on the unit operation scale, with little consideration of whole-of-site or regional scale effects. This paper presents an application of a hierarchical systems model (HSM) developed to represent water, energy and GHG emissions fluxes at scales ranging from the unit operation, to the site level, to the regional level. The model allows for the linkages between water use, energy use and GHG emissions to be examined in a fl exible and intuitive way, so that mine sites can predict energy and emissions impacts of water use reduction schemes and vice versa. This paper examines whether this approach can also be applied to the regional scale with multiple mine sites. The model is used to conduct a case study of several coal mines in the Bowen Basin, Australia, to compare the utility of centralised and decentralised mine water treatment schemes. The case study takes into account geographical factors (such as water pumping distances and elevations), economic factors (such as capital and operating cost curves for desalination treatment plants) and regional factors (such as regionally varying climates and associated variance in mine water volumes and quality). The case study results indicate that treatment of saline mine water incurs a trade-off between water and energy use in all cases. However, significant cost differences between centralised and decentralised schemes can be observed in a simple economic analysis. Further research will examine the possibility for deriving model up-scaling algorithms to reduce computational requirements.

Artemisinin-induced parasite dormancy : a plausible mechanism for treatment failure

Background Artemisinin-combination therapy is a highly effective treatment for uncomplicated falciparum malaria but parasite recrudescence has been commonly reported following artemisinin (ART) monotherapy. The dormancy recovery hypothesis has been proposed to explain this phenomenon, which is different from the slower parasite clearance times reported as the first evidence of the development of ART resistance. Methods In this study, an existing P. falciparum infection model is modified to incorporate the hypothesis of dormancy. Published in vitro data describing the characteristics of dormant parasites is used to explore whether dormancy alone could be responsible for the high recrudescence rates observed in field studies using monotherapy. Several treatment regimens and dormancy rates were simulated to investigate the rate of clinical and parasitological failure following treatment. Results The model output indicates that following a single treatment with ART parasitological and clinical failures occur in up to 77% and 67% of simulations, respectively. These rates rapidly decline with repeated treatment and are sensitive to the assumed dormancy rate. The simulated parasitological and clinical treatment failure rates after 3 and 7 days of treatment are comparable to those reported from several field trials. Conclusions Although further studies are required to confirm dormancy in vivo, this theoretical study adds support for the hypothesis, highlighting the potential role of this parasite sub-population in treatment failure following monotherapy and reinforcing the importance of using ART in combination with other anti-malarials.

In Response: "Oral versus IV treatment for catheter-related bloodstream infections - by Burke A. Cunha"

In his letter Cunha suggests that oral antibiotic therapy is safer and less expensive than intravenous therapy via central venous catheters (CVCs) (1). The implication is that costs will fall and increased health benefits will be enjoyed resulting in a gain in efficiency within the healthcare system. CVCs are often used in critically ill patients to deliver antimicrobial therapy, but expose patients to a risk of catheter-related bloodstream infection (CRBSI). Our current knowledge about the efficiency (i.e. costeffectiveness) of allocating resources toward interventions that prevent CRBSI in patients requiring a CVC has already been reviewed (2). If for some patient groups antimicrobial therapy can be delivered orally, instead of through a CVC, then the costs and benefits of this alternate strategy should be evaluated...

Sensitivity of an Elekta iView GT a-Si EPID model to delivery errors for pre-treatment verification of IMRT fields

A Monte Carlo model of an Elekta iViewGT amorphous silicon electronic portal imaging device (a-Si EPID) has been validated for pre-treatment verification of clinical IMRT treatment plans. The simulations involved the use of the BEAMnrc and DOSXYZnrc Monte Carlo codes to predict the response of the iViewGT a-Si EPID model. The predicted EPID images were compared to the measured images obtained from the experiment. The measured EPID images were obtained by delivering a photon beam from an Elekta Synergy linac to the Elekta iViewGT a-Si EPID. The a-Si EPID was used with no additional build-up material. Frame averaged EPID images were acquired and processed using in-house software. The agreement between the predicted and measured images was analyzed using the gamma analysis technique with acceptance criteria of 3% / 3 mm. The results show that the predicted EPID images for four clinical IMRT treatment plans have a good agreement with the measured EPID signal. Three prostate IMRT plans were found to have an average gamma pass rate of more than 95.0 % and a spinal IMRT plan has the average gamma pass rate of 94.3 %. During the period of performing this work a routine MLC calibration was performed and one of the IMRT treatments re-measured with the EPID. A change in the gamma pass rate for one field was observed. This was the motivation for a series of experiments to investigate the sensitivity of the method by introducing delivery errors, MLC position and dosimetric overshoot, into the simulated EPID images. The method was found to be sensitive to 1 mm leaf position errors and 10% overshoot errors.

Doctors' knowledge of the law on withholding and withdrawing life-sustaining medical treatment

Objectives To examine the level of knowledge of doctors about the law on withholding and withdrawing life-sustaining treatment from adults who lack decision-making capacity, and factors associated with a higher level of knowledge. Design, setting and participants Postal survey of all specialists in emergency medicine, geriatric medicine, intensive care, medical oncology, palliative medicine, renal medicine and respiratory medicine on the AMPCo Direct database in New South Wales, Victoria and Queensland. Survey initially posted to participants on 18 July 2012 and closed on 31 January 2013. Main outcome measures Medical specialists’ levels of knowledge about the law, based on their responses to two survey questions. Results Overall response rate was 32%. For the seven statements contained in the two questions about the law, the mean knowledge score was 3.26 out of 7. State and specialty were the strongest predictors of legal knowledge. Conclusions Among doctors who practise in the end-of-life field, there are some significant knowledge gaps about the law on withholding and withdrawing life-sustaining treatment from adults who lack decision-making capacity. Significant consequences for both patients and doctors can flow from a failure to comply with the law. Steps should be taken to improve doctors’ legal knowledge in this area and to harmonise the law across Australia.

The automation of radiotherapy treatment planning assessment

Aim The assessment of treatment plans is an important component in the education of radiation therapists. The establishment of a grade for a plan is currently based on subjective assessment of a range of criteria. The automation of assessment could provide a number of advantages including faster feedback, reduced chance of human error, and simpler aggregation of past results. Method A collection of treatments planned by a cohort of 27 second year radiation therapy students were selected for quantitative evaluation. Treatment sites included the bladder, cervix, larynx, parotid and prostate, although only the larynx plans had been assessed in detail. The plans were designed with the Pinnacle system and exported using the DICOM framework. Assessment criteria included beam arrangement optimisation, volume contouring, target dose coverage and homogeneity, and organ-at-risk sparing. The in-house Treatment and Dose Assessor (TADA) software1 was evaluated for suitability in assisting with the quantitative assessment of these plans. Dose volume data were exported in per-student and per-structure data tables, along with beam complexity metrics, dose volume histograms, and reports on naming conventions. Results The treatment plans were exported and processed using TADA, with the processing of all 27 plans for each treatment site taking less than two minutes. Naming conventions were successfully checked against a reference protocol. Significant variations between student plans were found. Correlation with assessment feedback was established for the larynx plans. Conclusion The data generated could be used to inform the selection of future assessment criteria, monitor student development, and provide useful feedback to the students. The provision of objective, quantitative evaluations of plan quality would be a valuable addition to not only radiotherapy education programmes but also for staff development and potentially credentialing methods. New functionality within TADA developed for this work could be applied clinically to, for example, evaluate protocol compliance.

Save Your Life Tonight : Heads Up

Save Your Life Tonight is a factual entertainment series produced by WildBear Entertainment for the Australian Broadcasting Corporation (ABC) and was filmed in front of a live studio audience at Royal Brisbane and Women's Hospital (RBWH). Save Your Life Tonight is a unique studio based medical series that explores Australia’s top 10 health issues in an exciting and entertaining way. Driven by charismatic host Andrew Daddo, along with resident GP Dr Liz Marles and a panel of leading experts, each episode is a fast-paced, dynamic exploration of the causes, symptoms, treatments and, most importantly, prevention of these leading health issues. But Save Your Life Tonight doesn't just talk about the issues, it shows the issues! Save Your Life Tonight features real patients, real doctors, real tests, real diagnoses, and real surgical procedures – live on stage! For the "Heads Up" episode, the program explores the issues of mental health. Only half of the Australians suffering from severe mental heath issues are receiving treatment. Featuring Ian Hickie on the panel, we also see a young mum face her crippling bird phobia with the help of a Wedge Tailed Eagle.

New regime for property agents and residential property sales in Queensland : Property Occupations Act 2014

This article examines the new Property Occupations Act 2014 (POA) and relevant provisions of the Agents Financial Administration Act 2014 (AFAA) and the impacts for property practitioners. The Acts are due to commence later in 2014 once regulations and relevant forms are drafted. Coinciding with the commencement of the Acts further versions of the REIQ Houses and Land Contract and REIQ Community Title Contract will also be released. The POA introduces changes for licencing of real estate agents, property developers and resident letting agents as well as significant changes for the contract formation process. The AFAA includes the trust account and claim fund provisions of PAMDA, which avoids duplication of these provisions across each of the industry-specific Bills. The most significant change is to the process for making a claim against the fund for the conduct of property agents.