Simulation of a novel piezoelectric energy harvester

This paper focuses on a novel piezoelectric energy harvester for nanofiber PVDF to capture energy from vibration environment. A Resembling CMOS(R-CMOS) circuit consisting of two pMOS transistors and two nMOS transistors is presented, which can greatly increase the energy efficiency and reduce the power dissipation tremendously. Meanwhile, the novel harvester supplies smooth direct current. Simulation result of MULTISIM has shown that by using this novel piezoelectric energy harvester the input voltage (5v) can be rectified to be an output voltage (4.24v). The voltage conversion rate of the novel harvester is as high as 84.8% which is much larger than the rate of traditional rectifier circuit. Its potential application is in micro sensors, wireless transducers, and sensor networks.

A simple motion heuristic for controlling mobile sinks in delay tolerant sensor networks

Optimising energy consumption in wireless sensor networks is of dominant importance. Sink mobility is introduced to deal with this problem by approaching the sensor nodes and collecting their data buffers using the less energy demanding single-hop communication. The sink route is very crucial for the data collection operation performed in the network especially when the collection requests generated by the sensors are revealed dynamically to the sink and not known ahead. This paper presents a practical motion heuristic for constructing the sink route based on the dynamic arrival of the collection requests. Three control schemes are proposed for coordinating the interaction of multiple mobile sinks collectively performing the data collection in the network. The main objective is maximising the data collected by each mobile sink while minimising the sleeping time of each sensor awaiting the collection service. Simulation results show the performance of the mobile sinks under the proposed control schemes and the impact of the motion heuristic on the sensors' sleeping time in the network.

Springback data from stamping and simulating the forming of advanced high strength steel

This dataset is comprised of a spreadsheet of simulation result files, cross-section geometries of stamped parts, strain results of cross-section of stamped parts, simulation data (strain stress displacement energies), and variation data of material properties of a single coil. This data is a collection of both experimental and simulation results from industrial and laboratory stamping of advanced high strength steels (AHSS). The steels that were stamped were a typical high-strength low-alloy (HSLA) steel, a transformation-induced plasticity (TRIP) steel, a super HSLA steel, and a dual phase (DP) steel. The selected part was an automatic Ford Falcon front cross-member component using the Ford Geelong stamping plant. The variation of the material and stamped parts was also collected.

E-commerce trust management system reliability

Various solutions have been proposed in managing trust relationship between trading partners in eCommerce environment. Determine the reliability of trust management systems in eCommerce is most difficult issue due to highly dynamic nature of eCommerce environments. As trust management systems depend on the feedback ratings provided by the trading partners, they are fallible to strategic manipulation of the feedback ratings attacks. This paper addressed the challenges of trust management systems. The requirements of a reliable trust management are also discussed. In particular, we introduce an adaptive credibility model that distinguishes between credible feedback ratings and malicious feedback ratings by considering transaction size, frequency of ratings and majority vote to form a feedback ratings verification metric. The approach has been validated by simulation result.

Optimum design and analysis study of stand-alone residential solar PV microgrid

Today’s power system network has become more complex and it has more responsibilities and challenges to provide secure, reliable and quality energysupply to the communities. A small entity of electrical network known as Microgrid (MG) is more popular nowadays to enhance reliablity and secure level of energy supply, in case of any energy crisis in the utility network. The MG can also provide clean energy supply by integrating renewable energy sources effectively. TheMG with small scale solar photovoltaic (PV) power system is more suitable to provide reliable and clean energy supply for remote or urban communities in residential level. This paper presents the basic analysis study of stand-alone solar photovoltaic (PV) MG power system which has been developed with the aid of Matlab - Simulink software, on the basis of residential load profile and solar exposure level in a particular area of Geelong, Victoria State. The simulation result depicts the control behavior of MG power system with optimum sizing of PV (4.385 kW)and battery storage (480Ah/48V) facility, fulfills daily energy needs in residential load level. This study provides a good platform to develop an effective and reliable stand-alone MG power system for the remote communities in the near future.

Research of a new type rectifier and voltage-multiplier piezoelectric energy harvester circuit

Traditional rectifier circuit can convert AC to DC, but some disadvantages can't be avoided, such as small output current, high power consumption, low conversion efficiency. This paper designs a new type of rectifier voltage-multiplier circuit named MR MOS circuit. It uses a low let-through resistance MOS tube to replace the conventional rectifier diode, and adds the voltage-multiplying factor to the synchronous input port. Therefore, it can improve the rectifier effect and increase the output voltage. By the simulation result of Synopsys Saber Platform, it shows that the new type circuit can implement the rectification and voltage-multiplying by the simulating output pulse voltage of nano fiber made in Deakin University as the source of excitation. It can provide the basic theoretical of the piezoelectric energy harvester (PEH) development, and has certain reference significance to the development of piezoelectricity technology. © (2014) Trans Tech Publications.

A kinematic based evaluation of upper extremity movement smoothness for tele-rehabilitation

Tele-rehabilitation has been widely studied in recent year, although a number of crucial issues has not been addressed. Quantitatively assessing exercise performance is vital in monitoring the progress in exercise based rehabilitation. This allows physiotherapists not only to refine rehabilitation plans, but also provides instant feedback to patients and facilitate the exercise performance in non-clinical setting. In this paper, we propose to evaluate the performance of upper extremity reaching tasks with in a kinematic perspective by assessing the smoothness of motion trajectories with the entropy of shape model, including curvature and torsion. The simulation result confirms that approximate entropy of shape model is consistent with the change of the smoothness in motion trajectory while it is capable of classifying six levels of the ability to perform upper extremity reaching tasks with higher accuracy.

Hybrid controller with the combination of FLC and neural network-based IMC for nonlinear processes

This work presents a hybrid controller based on the combination of fuzzy logic control (FLC) mechanism and internal model-based control (IMC). Neural network-based inverse and forward models are developed for IMC. After designing the FLC and IMC independently, they are combined in parallel to produce a single control signal. Mean averaging mechanism is used to combine the prediction of both controllers. Finally, performance of the proposed hybrid controller is studied for a nonlinear numerical plant model (NNPM). Simulation result shows the proposed hybrid controller outperforms both FLC and IMC.

Waste production simulation for building deconstruction projects

The recently erected concept of building deconstruction has significantly promoted building components and materials reuse and recycling where building is carefully dismantled into reusable parts. Current research and practices of building deconstruction mainly focus on issues of process before and during the deconstruction such as hazardous material detection, deconstruction design and deconstruction technology. The issues after the deconstruction project are rarely considered. Waste reuse and recycling are enabled through deconstruction yet not practically achieved, and especially the demands of waste building components and materials are hard to appear and match the actual waste production in a building deconstruction project. To deal with this awkward situation, the waste production needs to be conducted in a demand-oriented way. It needs to be thoughtfully planned and scheduled prior to the physical deconstruction as an essential portion of deconstruction project planning and scheduling. Furthermore, the relationship between waste production and structural characteristics of the building creates a serious consideration affecting a deconstruction plan. As a result, a waste production simulation will facilitate waste reuse and recycling in a deconstruction project. It serves as a crucial section of deconstruction planning and design. This research aims to describe the concept of waste production simulation and investigate various management and technical aspects of waste production simulation for building deconstruction projects.

Computational simulation of gas flow and heat transfer near an immersed object in fluidized beds

To improve the understanding of the heat transfer mechanism and to find a reliable and simple heat-transfer model, the gas flow and heat transfer between fluidized beds and the surfaces of an immersed object is numerically simulated based on a double particle-layer and porous medium model. The velocity field and temperature distribution of the gas and particles are analysed during the heat transfer process. The simulation shows that the change of gas velocity with the distance from immersed surface is consistent with the variation of bed voidage, and is used to validate approximately dimensional analysing result that the gas velocity between immersed surface and particles is 4.6Umf/εmf. The effects of particle size and particle residence time on the thermal penetration depth and the heat-transfer coefficients are also discussed.

Computer mediated simulation learning opportunities

Market approaches have effected both the health care and higher education sectors in Australia. As a result of changes to funding the nursing profession has had to develop strategies in an effort to continue to provide adequate under-graduate nursing education. Specifically, new education challenges have occurred due to the shortage of experienced clinical nursing staff and reduced supply of clinical placements for undergraduate students. In light of the market forces we discuss computers as providers of simulation learning opportunities and a viable means of responding to the constraints and improving undergraduate nurse education.

Simulation of contact pressure in sheet metal trimming/blanking process

In the car body stamping process, trim/blank die cutting edges are subjected to very high tribological loads that result in loss of tool material from both the punch and die cutting edges. According to Archard’s wear model, normal contact force and sliding distance directly affects the wear. Therefore, knowledge of the acting forces on local contact areas has a pivotal role towards the prediction of tool wear. This paper presents a finite element modelling approach to determining the contact pressure distribution on the tool cutting edges during a trimming/blanking process. Characteristic areas on sheared edge profile, variation of punch force and high contact pressures affected areas have also been analysed.