An accurate numerical scheme for the contraction of a bubble in a Hele-Shaw cell

We report on an accurate numerical scheme for the evolution of an inviscid bubble in radial Hele-Shaw flow, where the nonlinear boundary effects of surface tension and kinetic undercooling are included on the bubble-fluid interface. As well as demonstrating the onset of the Saffman-Taylor instability for growing bubbles, the numerical method is used to show the effect of the boundary conditions on the separation (pinch-off) of a contracting bubble into multiple bubbles, and the existence of multiple possible asymptotic bubble shapes in the extinction limit. The numerical scheme also allows for the accurate computation of bubbles which pinch off very close to the theoretical extinction time, raising the possibility of computing solutions for the evolution of bubbles with non-generic extinction behaviour.

A Flight control scheme to improve position tracking performance of rotary-wing UASs

This paper outlines an innovative and feasible flight control scheme for a rotary-wing unmanned aerial system (RUAS) with guaranteed safety and reliable flight quality in a gusty environment. The proposed control methodology aims to increase gust-attenuation capability of a RUAS to ensure improved flight performance when strong gusts occur. Based on the design of an effective estimator, an altitude controller is firstly constructed to synchronously compensate for fluctuations of the main rotor thrust which might lead to crashes in a gusty environment. Afterwards, a nonlinear state feedback controller is proposed to stabilize horizontal positions of the RUAS with gust-attenuation property. Performance of the proposed control framework is evaluated using parameters of a Vario XLC helicopter and high-fidelity simulations show that the proposed controllers can effectively reduce side-effect of gusts and demonstrate performance improvement when compared with the proportional-integral-derivative (PID) controllers.

Key derivation function : the SCKDF scheme

A key derivation function is used to generate one or more cryptographic keys from a private (secret) input value. This paper proposes a new method for constructing a generic stream cipher based key derivation function. We show that our proposed key derivation function based on stream ciphers is secure if the underlying stream cipher is secure. We simulate instances of this stream cipher based key derivation function using three eStream finalist: Trivium, Sosemanuk and Rabbit. The simulation results show these stream cipher based key derivation functions offer efficiency advantages over the more commonly used key derivation functions based on block ciphers and hash functions.

Implementation and removal of an affirmative-action quota : the impact on task assignment and workers’ skill acquisition

Both the United States and Canada have federal legislation that attempts to address employment inequities across specific target groups. The US has a long tradition of affirmative action, dating back to President Kennedy’s 1961 Executive Order; Canada enacted its Employment Equity Act in 1986. Employment Equity/Affirmative Action policy has attracted significant controversy, with high profile court cases and the repeal of state/provincial legislation. Coate and Loury (1993) examine the theoretical impact of introducing affirmative action. Unfortunately the theoretical impact of affirmative action is ambiguous. The current paper employs a laboratory experiment to shed empirical light on this theoretical ambiguity.

Confirmation of the assignment of vibrations of goethite: An ATR and IES study of goethite structure

Transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM/EDS) and X-ray diffraction (XRD) were used to characterize the morphology of synthetic goethite. The behavior of the hydroxyl/water molecular units of goethite and its thermally treated products were characterized using Fourier transform-infrared emission spectroscopy (FT-IES) and attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy. The results showed that all the expected vibrational bands between 4000 and 650 cm−1 including the resolved bands (3800–2200 cm−1) were confirmed. A band attributed to a new type of hydroxyl unit was found at 3708 cm−1 and assigned to the FeO–H stretching vibration without hydrogen bonding. This hydroxyl unit was retained up to the thermal treatment temperature of 500 °C. On the whole, seven kinds of hydroxyl units, involving three surface hydroxyls, a bulk hydroxyl, a FeO–H without hydrogen bonding, a nonstoichiometric hydroxyl and a reversed hydroxyl were observed, and three kinds of adsorbed water were found in/on goethite.

Regional chromosomal assignment of human renin gene to 1q12→qter and use in linkage studies in Charcot-Marie-Tooth disease

The gene for renin, previously mapped to human chromosome 1, was further localized to 1q12 → qter using human-mouse somatic cell hybrid DNAs. The renin DNA probe used (λ HR5) could detect a HindIII restriction fragment length polymorphism. When used in studies of 12 informative families, no linkage could be found between the renin and Charcot-Marie-Tooth disease. Furthermore, an association of any renin allele with hypertension was not apparent.

A flexible protection scheme for an islanded Multi-Microgrid

Multi-Microgrids (MMGs) have been proposed to connect distributed generators (DG), microgrids (MG), and medium-voltage (MV) loads with the distribution system. A flexible protection scheme that enables an islanded MMG to continue operation during fault conditions is yet to be developed. In this paper, a protection scheme for an islanded MMG that utilises MG controllers and communication links is proposed. The MMG model used includes two MGs connected to the distribution system. Each MG consists of diesel, wind, and photovoltaic (PV) microsources. The effectiveness of the proposed protection scheme is evaluated by simulation.

A novel real time pricing scheme for demand response in residential distribution systems

Price based technique is one way to handle increase in peak demand and deal with voltage violations in residential distribution systems. This paper proposes an improved real time pricing scheme for residential customers with demand response option. Smart meters and in-home display units are used to broadcast the price and appropriate load adjustment signals. Customers are given an opportunity to respond to the signals and adjust the loads. This scheme helps distribution companies to deal with overloading problems and voltage issues in a more efficient way. Also, variations in wholesale electricity prices are passed on to electricity customers to take collective measure to reduce network peak demand. It is ensured that both customers and utility are benefitted by this scheme.

Demand response for residential appliances via Customer Reward Scheme

This paper proposes a reward based demand response algorithm for residential customers to shave network peaks. Customer survey information is used to calculate various criteria indices reflecting their priority and flexibility. Criteria indices and sensitivity based house ranking is used for appropriate load selection in the feeder for demand response. Customer Rewards (CR) are paid based on load shift and voltage improvement due to load adjustment. The proposed algorithm can be deployed in residential distribution networks using a two-level hierarchical control scheme. Realistic residential load model consisting of non-controllable and controllable appliances is considered in this study. The effectiveness of the proposed demand response scheme on the annual load growth of the feeder is also investigated. Simulation results show that reduced peak demand, improved network voltage performance, and customer satisfaction can be achieved.

The National Disability Insurance Scheme Handbook

"The National Disability Insurance Scheme (NDIS) was launched on 1 July 2013. The NDIS Act 2013 is an historic piece of legislation that is the foundation for a national scheme which will deliver meaningful change for people with disabilities across Australia. The NDIS seeks to support the independence and social and economic participation of people with a disability, mainly by funding the provision of reasonable and necessary supports, including early intervention supports. The NDIS establishes three main criteria for access to the scheme - age, residence and disability. The National Disability Insurance Scheme Handbook written by Bill Madden, Janine McIlwraith and Ruanne Brell examines the NDIS from the viewpoint of a person seeking to access the NDIS and those advising or assisting them. The three key criteria are examined, along with the powers of the NDIS Chief Executive Officer and the scope for review of adverse decisions. The important area of interplay between the NDIS and compensation entitlements is carefully scrutinised. This handbook provides scheme users, carers, lawyers and health practitioners with an easy to understand guide to this watershed legal development."--Publisher website

A distributed control based coordination scheme of household PV systems for overvoltage prevention

This paper presents a distributed communication based active power curtailment (APC) control scheme for grid connected photovoltaic (PV) systems to address voltage rise. A simple distribution feeder model is presented and simulated using MATLAB. The resource sharing based control scheme proposed is shown to be effective at reducing voltage rise during times of peak generation and low load. Simulations also show the even distribution of APC using simple communications. Simulations demonstrate the versatility of the proposed control method under major communication failure conditions. Further research may lead to possible applications in coordinated electric vehicle (EV) charging.

The application of BESS in load shedding scheme

With new developments in battery technologies, increasing application of Battery Energy Storage System (BESS) in power system is anticipated in near future. BESS has already been used for primary frequency regulation in the past. This paper examines the feasibility of using BESS with load shedding, in application for large disturbances in power system. Load shedding is one of the conventional ways during large disturbances, and the performance of frequency control will increase in combination with BESS application. According to the latest news, BESS which are applied in high power side will be employed in practice in next 5 year. A simple low order SMR model is used as a test system, while an incremental model of BESS is applied in this paper. As continuous disturbances are not the main concern in this paper, df/dt is not considered in article.

The development of an effective and efficient dispute resolution processes for strata scheme disputes in peninsular Malaysia

Dispute resolution in strata schemes in Peninsular Malaysia should focus on more than just "settlement." The quality of the outcome, its sustainability and its relevance in supporting the basic principles of a good neighbourhood and self-governance in a strata scheme are also fundamental. Based on the comprehensive law movement, this thesis develops a theoretical framework for strata scheme disputes within the parameters of therapeutic jurisprudence, preventive law, alternative dispute resolution (ADR) and problem-solving courts. The therapeutic orientation of this model offers approaches that promote positive communication between disputing parties, preserve neighbour relations and optimise people's psychological and emotional well-being.

An efficient scheme of common secure indices for conjunctive keyword-based retrieval on encrypted data

We consider the following problem: members in a dynamic group retrieve their encrypted data from an untrusted server based on keywords and without any loss of data confidentiality and member’s privacy. In this paper, we investigate common secure indices for conjunctive keyword-based retrieval over encrypted data, and construct an efficient scheme from Wang et al. dynamic accumulator, Nyberg combinatorial accumulator and Kiayias et al. public-key encryption system. The proposed scheme is trapdoorless and keyword-field free. The security is proved under the random oracle, decisional composite residuosity and extended strong RSA assumptions.