The Real-Time Publisher/Subscriber Communication Model for Distributed Substation Systems

In the past decade, new communication schemes have been designed and retrofitted into substations by utilities to integrate data from relays and intelligent electronic devices (IEDs) and capitalize on the protection, control, metering, fault recording and communication functions available in digital devices. The introduction of IEC 61850 has made it possible and justifiable to integrate station IEDs on a high-speed peer-to-peer communication network (Ethernet) through standardization. However, more advances are needed in order to establish an open and standard working environment allowing for more functions to be developed. In this paper, the authors propose a real-time publisher/subscriber communication model as a means of satisfying the unique behavior and communications needs of the IEC 61850 protocol. The authors provide a detailed design and implementation detail of this model along with interesting performance results. The target audience for this paper includes power system protection and automation engineers and technicians as well as research personnel who have at least a basic understanding of the IEC 61850 international standard and other technology mechanisms addressed in this paper.     

Design and implementation of an optimised wireless pressure sensor for biomedical application

This paper presents design and implementation of a wireless pressure sensor system for biomedical application. The system consists of a front-end Micro-Electro- Mechanical System (MEMS) sensing capacitor along with an optimised MEMS-based oscillator for signal conditioning circuit. In this design, vertical fringed comb capacitor is employed due to the advantages of smaller area, higher linearity and larger full scale change in capacitance compared to parallel plate counterparts. The MEMS components are designed in Coventorware design suite and their Verilog-A models are extracted and then imported to Cadence for co-simulation with the CMOS section of the system using AMI 0.6-micron CMOS process. In this paper, an optimisation method to significantly reduce the system power consumption while maintaining the system performance sufficient is also proposed. A phase noise optimisation approach is based on the algorithm to limit the oscillator tail current. Results show that for the pressure range of 0–300 mmHg the device capacitance range of 1.31 pF – 1.98 pF is achieved which results in a frequency sweep of 2.54 GHz – 1.95 GHz. Results also indicate that a 42% reduction of power consumption is achieved when the optimisation algorithm is applied. This characteristic makes the sensor system a better candidate for wireless biomedical applications where power consumption is the major factor. Hai Phuong Le received his B.E. (Hons) degree in Electronic and Computer System Engineering from University of Tasmania, Hobart, Australia in 2000. He received his Ph.D. degree in Microelectronics from Victoria University, Melbourne, Australia in 2005. At present, he is a post-doctoral research fellow and lecturer in the Centre for Telecommunications and Microelectronics, Victoria University. His research and teaching interests include data acquisition system, mixed-signal integrated circuit design and wireless smart sensor systems. Kriyang Shah received his B.E. Degree in Electronics and Communication Engineering from Sardar Patel University, Vallabh Vidyanagar, Gujarat, India and his Master Degree in Microelectronics in 2004. He is currently a Ph.D. research student in the Centre for Telecommunications and Microelectronics, Victoria University, Melbourne, Australia. His research interests include MEMS Sensors, RF MEMS, process integration for MEMS and CMOS and MEMS-CMOS co-simulation. Jugdutt (Jack) Singh received his B.Sc. in Electronics Engineering from University of Brighton, UK and M.Sc. in Electronics Engineering from University of Alberta, Canada in 1978 and 1986 respectively. He completed his Ph.D. at Victoria University, Australia in 1997. Since 1989 he has been at Victoria University, Melbourne, Australia. Currently he is a Professor of Microelectronics in the Centre for Telecommunications and Microelectronics at Victoria University. His major area of research interests are in the RF, analog and mixed signal design, reconfigurable architectures, low power VLSI circuits and systems design. He has published number of articles in education and research in microelectronics and small technologies area. Aladin Zayegh received his B.E. degree in Electrical Engineering from Aleppo University in 1970 and Ph.D. degree from Claude Bernard University, France in 1979. In 1980, he joined the Faculty of Engineering, Tripoli, Libya. Since 1984 he has held lecturing position at Victoria University, Melbourne, Australia. He is currently an Associate Professor and the Head of School in the School of Electrical Engineering, Faculty of Health, Engineering and Engineering and Science at Victoria University. His research interest includes microprocessor-based system, instrumentation, data acquisition and interfacing, and microelectronics.     

Data clustering based on quantum synchronization

Natural Computing - There exists a specific class of methods for data clustering problem inspired by synchronization of coupled oscillators. This approach requires an extension of the classical...     

Lipid and Nucleic Acid Chemistries: Combining the Best of Both Worlds to Construct Advanced Biomaterials

Hybrid synthetic amphiphilic biomolecules are emerging as promising supramolecular materials for biomedical and technological applications. Herein, recent progress in the field of nucleic acid based lipids is highlighted with an emphasis on their molecular design, synthesis, supramolecular properties, physicochemical behaviors, and applications in the field of health science and technology. In the first section, the design and the study of nucleolipids are in focus and then the glyconucleolipid family is discussed. In the last section, recent contributions of responsive materials involving nucleolipids and their use as smart drug delivery systems are discussed. The supramolecular materials generated by nucleic acid based lipids open new challenges for biomedical applications, including the fields of medicinal chemistry, biosensors, biomaterials for tissue engineering, drug delivery, and the decontamination of nanoparticles.     

Recent developments in microgrids and example cases around the world—A review

Climate change concerns due to the rising amounts of the carbon gas in the atmosphere have in the last decade or so initiated a fast pace of technological advances in the renewable energy industry. Such developments in technology and the move towards cleaner sources of energy have made distributed generation (DG) from renewable resources more desirable. However, it is a known fact that rising penetrations of DG can have adverse impacts on the grid structure and its operation. The microgrid concept is a solution proposed to control the impact of DG and make conventional grids more suitable for large scale deployments of DG. Covering many aspects of the power systems and power electronics fields, microgrids have become a very popular research field. This paper reviews the background and the concept of a microgrid, the current status of the literature, on-going research projects, and the relevant standards. It also presents a review of the microgrid pilot projects around the world in further detail and discusses the potential avenues for further research.     

Performance analysis of optimised CMOS comparator

A high-speed low-power latched CMOS comparator circuit is presented. Demonstrated is a circuit optimisation technique to obtain minimum offset error at 500 MHz sampling speed. Also, a mathematical model representing the noise in the device is developed. After optimisation, the comparator achieved 10-bit resolution on a 1 V differential input at 500 MHz speed and had a noise figure of 4.747 dB at this frequency.     

Optimal Control over Wave Motions of a Piezoceramic Rod

We solve the direct problem of longitudinal wave motions of a piezoceramic rod under the action of electric excitations variable as a function of time. The solutions obtained as a result explicitly depend on the applied voltage. Interpreting the rate of changes in the electric voltage as a function of control, we pose and solve two problems of optimal control, namely, the problem of transfer of the observed points of the rod into prescribed positions by minimizing the norm of control and the problem of transfer of the rod with the best possible rate and certain restrictions imposed on the norm of control. The results of numerical analysis of the time dependence of the optimal electric voltage applied to the rod are presented and the plot of the norm of optimal control versus the period of control is constructed.     

Flash ADC architecture

A 4-bit, 2.5 V modified flash analogue-to-digital converter (ADC) has been designed. In this design, the new flash topology only requires 2/sup (N-2)/+2 comparators. For comparison reasons, this new ADC architecture is operated at 400 MHz, consumes a total power of 1.68 mW and generates a total noise power of 4.86/spl times/10/sup -15/. /spl Delta/f(V/sup 2/) at this frequency.     

Modern state of the Small (Northern) Aral Sea fauna

The Aral Sea is a terminal lake lying within the deserts of Central Asia in Kazakhstan and Uzbekistan, draining the Amu Darya and Syr Darya rivers. Before the 1960s, it was a large brackish water lake with an average salinity of 10.3 g L^?1. The anthropogenic regression and salinization of the Aral Sea at that time resulted from increasing water withdrawals from the Amu Darya and Syr Darya for irrigation purposes. The salinization resulted in the disappearance of most of its invertebrates and all freshwater fish. As a result of the water level decrease, the Aral Sea divided into a northern Small Aral and a southern Large Aral at the end of the 1980s, with the two having different hydrological regimes. After construction the first Kokaral Dam in 1992, the water level of the Small Aral Sea increased by >1 m, with a gradual decline in the salinity beginning. To date, the Small Aral has again become brackish. Its average salinity reached 5.3 g L^?1 by April–May 2013, with the highest salinity of 9.9 g L^?1 in Butakov Bay, whereas the salinity was very low at 1.2–2.0 g L^?1 in the estuary zone of the Syr Darya. There is an ongoing process of restoration of the former biodiversity, with many fresh water and brackish water invertebrate species reappearing due to the decreasing salinity. Freshwater fish species (bream, roach, carp, asp, zander, wels, etc.) returned into the Small Aral from the Syr Darya River and lakes in its lower reaches where they survived. Fisheries are recovering and catches are growing. Continuing salinity decreases, however, may cause decreases in the numbers, or even disappearance, of marine and halophilic invertebrate species. This study summarizes the results of studies of the Small Aral zooplankton, zoobenthos and ichthyofauna carried out in the spring of 2013. An historical review of changes in the Aral Sea and its fauna also is presented.     

The Aral Sea and the Dead Sea: Disparate lakes with similar histories

In spite of significant differences in their sizes, depths, salinity and other properties, the Aral Sea and the Dead Sea share many features, as illustrated by a comparison of the histories of both water bodies. Fifteenth and early sixteenth century maps, based on the ‘Geography’ of Ptolemy, contain both lakes. The first successful limnological surveys of the lakes were made in the same year 1848, when Alexey Butakov explored the Aral Sea and William Lynch mapped the Dead Sea. Paintings and drawings by Taras Shevchenko (Aral Sea) and David Roberts (Dead Sea) document the landscapes around the lakes in the first half of the 19th century. The water balance of both lakes has been strongly negative in the past decades, leading to a decreased water surface area and volume for both lakes, their increased salinity and deterioration of their local infrastructures. Complex and expensive mitigation schemes have been proposed for both lakes, based on the import of large quantities of water from distant sources via canals or pipelines (i.e. Siberian rivers or Caspian Sea to supply water to the Aral Sea, Mediterranean Sea or Red Sea, to be connected with the Dead Sea). Less dramatic solutions to improve the local situations already have resulted in improved water quality in the Aral Sea, and partial restoration of its fisheries. In contrast, the Dead Sea remains much too saline to support higher forms of life. Nevertheless, a biblical prophecy predicts that even this most hypersaline of all lakes will eventually be teeming with fish of many kinds.