Ultrawideband as an Industrial Wireless Solution

Parallel processing in the era of many-core processors demands high-performance networks-on-chip and parallel communication based on intra-chip message passing. In this context, wireless networks-on-chip (WiNoCs) emerge to improve inter-core communication, bringing high bandwidth and low power consumption. In order to increase application performance, WiNoCs can support single-hop or multi-hop communication. The main issue is related to the performance of each communication architecture in the face of different parallel workloads. For this reason, the goal of this work is to evaluate and compare single- and multi-hop WiNoC architectures using parallel applications. The methodology is based on simulations done using the well-known simulator Network Simulator 2 (NS-2) and applications from NAS Parallel Benchmarks (NPB). The WiNoC architectures are based on 2-D mesh topology and ultra wide band (UWB) radio technology. The inter-core transmission is evaluated concerning unicast communication (1:1 and N:1) and broadcast communication (1:N and N:N). This work has, as contribution to the state-of-the-art, the evaluation of both WiNoC designs (single- and multi-hop architectures) with parallel applications. Based on our results, the single-hop architecture has lower communication delay than the multi-hop version, and for some workloads, there were no packet losses. However, to achieve high-performance communication, the single-hop architecture consumed 63.12 J for the 256-node network, versus 0.22 J consumed by the multi-hop version. Although single-hop WiNoCs reduce network bottlenecks and increase communication parallelism, they are recommended when energy consumption is not a critical factor.

Power efficient ultra-wideband based wireless communication for wireless body area network applications

Peculiarities of measuring equipment usage in the field of internal combustion engines and the rationality of methods for testing and results processing are considered. It is shown that one of the most difficult tasks in the study of the working processes of engines is to obtain a reliable indicator diagram with a given accuracy. It is noted that it is important to consider the features of the flow of rapidly changing and non-stationary processes in the internal combustion engine: high rates of processes change, a wide frequency spectrum, non-identity flow of the processes flow from cycle to cycle. This causes specific requirements to the methodological plan, as well as to measuring instruments themselves in terms of speed, recording frequency and rationality of the techniques of performing the experimental studies. It is proved that in the process of the engines investigation it is necessary to have both single-cycle indicator diagram and averaged, for several hundreds cycles, indicator diagram. It is shown that the objective of the work is to improve the methodology for choosing the discretization step and choosing the number of recorded ordinates of the internal combustion engine indicator diagram during one working cycle, depending on the approximation error and the rate of pressure increase. A general method for determining the sampling frequency of indicator diagrams depending on the required accuracy of its approximation is described; improved expressions for its determination are given. A scheme for determining the sampling frequency by the angle of crankshaft rotation is presented. The essence of improving the methodology for choosing the discretization step of the indicator diagram by dividing it into zones and selecting different sampling steps in each zone is considered in detail. The use of a digital microprocessor complex for the study of the working processes of a particular diesel engine is considered. The initial data and values of discretization angles, necessary for the experiment were determined.

WiMeida MAC, coupled with physical layer based on UWB technology, is now widely applied in high data rate wireless personal area networks (WPANs). Because the transmission with the UWB technology is restricted to a short range, multiple piconets may exist in a network at the same time. We investigate problems related to beacon collisions and data communication disruptions when piconets interfere into each other due to changes in propagation environment, moving devices, or other effects. For the purpose of resolving this problem and minimizing the cost, we propose a merger weight-based synchronization algorithm. The performance of the algorithm is simulated and compared with coordinated merger of BPs scheme provided in WiMedia MAC, and results show that there is room for further improvement over the current synchronization algorithm in WiMedia MAC.

Background: Fast Fourier Transform (FFT) processor is the important method in Orthogonal Frequency Division Multiplexing (OFDM) communication systems. Split-Radix Fast Fourier Transform (SRFFT) estimates the least number of multiplications compared to other FFT algorithm; hence SRFFT is the best for the implementation of low power FFT processor. Methods: In this paper, the proposed “pipelined 32-point Split-Radix Multi-path Delay Commutator (SFMDC) FFT” architecture is designed. The MDC architecture has advantages in reducing the low chip area and lower power consumption. The SR-FFT algorithm has changing the numbers of butterfly elements in successive stages. The 32-point SR-MDC FFT architecture is to determine the frequency transformation techniques. The Split-Radix FFT algorithm is based on radix-2 and radix-4 algorithm and it is related to mixed radix FFT. Findings: The performance evaluation of proposed architecture is determined through VLSI System. Less area, low power consumption and high speed are the main parameters in this design. The proposed structure provides high throughput rate and low hardware complexity. Improvements: The goal of this proposed work is to reduce the slices and LUTs and power consumption and also to enhance the performances of the FFT processor than the existing method. The proposed method has been evaluated by using ModelSim 6.3C and synthesis results has been validated by using Xilinx Plan ahead 12.4.

Long-term occupational exposure to whole-body vibration increases the risk of disc degeneration and the consequent back pain [1]. The pathogenesis of vibration induced disorders is still not completely clear and there is no effective treatment. Although the potential effects of vibrational stress on extracellular matrix (ECM) assembly and degradation are particularly relevant to the clinical findings of the vibration induced disorders, the effects of vibrational loads on disc cells are largely unknown. It has been shown that hydrostatic pressure directly affects the synthesis of collagen and proteoglycan by the intervertebral disc cells [2–5]. However, these studies investigated only the extent of the effect of quasi-static hydrostatic loads. During daily occupational activities intervertebral disc is exposed to dynamic oscillatory hydrostatic loads, characterized by wide frequency spectrum and variable amplitude. In this case, a physiologic level of amplitude and frequency of hydrostatic pressure may be essential for maintaining the matrix of the disc, while an abnormal amplitude and frequency of hydrostatic pressure may accelerate disc degeneration. The ranges of good and bad loading frequencies and amplitudes still need to be discovered. The objective of this study was to find which of loading frequency and loading amplitude has more influence in affecting disc cell response to vibration. To address this issue we developed a mechanically-active culture system capable of delivering a wide range of loading frequency and amplitude of hydrostatic pressure to cultures of nucleus pulposus cells. We used nucleus cells, which are exposed mainly to hydrostatic loading in vivo.

The paper proposes an initial benchmark set, suitable for substrate analysis and test. The aim is to help accurately represent electrical noise injected into and picked up from substrate in a variety of high performance circuits. Creating an accurate image of such noise is becoming a critical requirement with the expansion of real plug-and-play style designs. Several important methods for the analysis of substrate parasitic coupling are reviewed in light of the effect substrate noise has on the performance of analog and digital ICs over a wide frequency spectrum. The requirements and formats for each benchmark are described in full detail to allow possible algorithmic as well as signal integrity tests.

Non-invasive and radiation free medical imaging modalities for breast screening is increasingly in demand as the health care industry is taking a paradigm shift from the traditional “treating the sick” to “keeping people healthy” model. To address this need, we are developing a Nano Electrode Array based Electro Impedance Tomography (EIT) device.The objective of this device is to become the leading solution for accurate and cost-effective non-invasive and radiation free early breast cancer detection medical imaging modality.This will be the first medical imaging device to use nano-electrode array embedded in flexible textile as sensors (fabricated via MEMS processes) [1, 2, 3, 4, 5,6], scan across a wide frequency spectrum and allow scanning of both breasts simultaneously. In addition, it is also the first device that simultaneously allows the scanning of lymph nodes located under the arm, a feature which is of value to oncologists tracking progression and treatment of cancers.

This research focuses on improving the performance of ZigBee-based wireless communications in high impulsive noise environments such as those found in power utility and manufacturing facilities. Previous research has shown the physical layer used by the ZigBee standard to be vulnerable to impulsive noise due to its wide frequency spectrum and high energy content. Hence, our goal is to develop a novel protection scheme that limits the effects of impulsive noise on the ZigBee communication link. In this regard, a conventional Reed-Solomon encoder in combination with a novel composite comparison value filter is employed to manage impulsive noise. Our results indicate the ZigBee transmission performance is improved by our proposed approach.

Testing and verifying wireless systems in a real world environments is a challenging but an important problem. This is particular true for the Joint Tactical Radio System (JTRS) where the modulation techniques are optimized towards environments that are difficult to reproduce (e.g., ship to plane, plane to satellite communications). Such cases necessitate a wireless channel emulator to facilitate testing in the laboratory as the protocols are being developed. Furthermore, the increasing complexity of communications protocols and highly variable network scenarios force the channel emulator to support an accurate and complicated channel model that can scale to handle a large number of radios that operate across a wide frequency spectrum. We developed a unique channel impairment emulator prototype to meet these requirements. It maximizes the scalability and performance, operating in a frequency range of 2 MHz to 2 GHz. Moreover, our emulator design accommodates radio operation that use unknown frequency hopping techniques, which is increasingly common in JTRS systems. This key feature to this system is a high throughput channel tracker module that handles high bandwidth intermediate frequency (IF) signals while providing the scalability to handle a large number of channels.

Since the introduction of partial discharge (PD) detection, the majority of conventional electrical measurement of PD has been performed with detectors operating in narrow bandwidths from 10 kHz to 1 MHz for several decades. In the past decade, advances in electronic instrumentation have permitted the measurement of PD with bandwidths up to 1 GHz. Since PD pulses are fundamentally events with duration as low as a few nanoseconds which have a very wide frequency spectrum, comparing with narrow band PD detection, PD measurement with such ultra-wideband (UWB) detection methods can provide more information on the deterioration of stator winding insulation subjected to combined stresses. A UWB PD measuring technique with bandwidths from 20 kHz to 1 GHz is presented, and some waveforms of UWB PD signals of stator bar specimens in different aging periods both in time domain and frequency domain are given in this paper. It has been found that the ultra high frequency components contained in PD pulse increase and the rise-time of the pulse decrease gradually with aging time. It would be suggested that the ultra high components of PD pulse may be used to characterize the aging degree of stator winding insulation.

In this study, we have investigated the toxic effects of tobacco smoke obtained from cigarettes treated in pulsed electromagnetic field in the rat. The treatment of cigarettes was accomplished before the initiation of animal studies after exposure of standard cigarettes to pulsed electromagnetic irradiation of low power (>10-7W) and wide frequency spectrum (30 Hz to 300 GHz) during 24 h according to the technology described in patents WO 01/26493, EP 1092354, US 2004/0206366A1 and AU2933700 entitled “Method for the Qualitative Improvement of the Products of Tobacco Plant”. Rats of both sexes were exposed to tobacco smoke obtained after burning 16 or 32 cigarettes per day during 90 days. The toxicity was assessed on the basis of clinical appearance, changes in behavior, biomarkers of exposure to tobacco smoke (carboxyhemoglobin in blood and thiocyanates in serum) and histopathological and morphological analysis of the lungs of all animals included in the study. The results obtained have shown that, the smoke generated from treated cigarettes formed significantly lower amount of carboxyhemoglobin in rats of both sexes when compared to standard nontreated cigarettes and the effect was dose-dependent. Tobacco smoke obtained from standard nontreated cigarettes induced significant dose-dependent increase of thiocyanate concentration in serum. However, in rats exposed to the smoke of treated cigarettes, there were no differences in thiocynate concentration when compared to controls not exposed to tobacco smoke. The results of morphometrical analysis in the rats exposed to tobacco smoke generated from standard nontreated cigarettes have shown statistically significant and dose-dependent decrease in participation of the lung parenchima in total lung surface up to 34% in male rats and up to 18% in female rats exposed to the higher dose of nontreated cigarette smoke. In addition, in these rats the mean alveolar circumference was incresed for about 17%. In rats exposed to the smoke of treated cigarettes there were no histopathological changes and differences in morphometrical parameters when compared to control animals. In conclusion, the results of this study have shown that, after treatment of cigarettes in pulsed electromagnetic field, the cigarettes produced tobaco smoke that was much less toxic in rats of both sexes exposed by inhalation route during 90 days when compared to the same cigarettes that were not treated in electromagnetic field. Key words: Tobacco smoke, carboxyhemoglobin, thiocyanates, pulsed electromagnetic field.

A frequency compensation scheme based on an active-feedback current buffer (AFCB) is presented in this paper. With an active-feedback mechanism, the proposed AFCB offers quite low input impedance across wide frequency spectrum, which greatly reduces the power consumption of AFCB amplifiers employing the AFCB as frequency compensation. The bandwidth and slew rate of the AFCB amplifier are also improved due to the much smaller compensation capacitors. Moreover, the presence of a left-half-plane zero in the AFCB amplifier enhances the stability and settling behavior of the amplifier. A three-stage AFCB amplifier is implemented by a standard 0.5-mum CMOS process. When driving a 120-pF capacitive load, the AFCB amplifier achieves over 100-dB DC gain, 4-MHz gain-bandwidth product (GBW), 65deg phase margin, and 1.9-V/mus average slew rate with total 3.5-pF compensation capacitances, while only dissipating 160-muW power at a 2.5-Vsupply

Inter-area oscillations are, by far, the most detrimental to the synchronous integrity of interconnected power systems. This detriment comes from their wide frequency spectrum and the large numbers of the participant generators. The inherent poor damping associated with the inter-area oscillations leaves open wide probabilities for irrevocable widespread blackouts with the consequent eventual devastating outcomes measured in terms of the huge economic casualties and the possible human fatalities. This article explores the influences of the Interval Type-2 fuzzy logic-based strategized dynamic braking interventions of dual brake models, namely Thyristor Controlled Braking Resistors (TCBRs), for neutralizing the jeopardy of negatively damped inter-area power oscillations in Kundur’s two-area test system, using MATLAB™/Simulink environment. The relative inner generator's speed deviation is employed in this work as a control signal to the proposed controller. The effectiveness of the proposed scheme is authenticated by considering four case studies with different severity degrees. By analyzing the performance repercussions due to four disturbances, without the implementation of the proposed scheme, the unstable nature of the system responses is clearly noticed. With the implementation of the proposed scheme, the system oscillatory behavior is stabilized in an appropriate manner. The performed comparative non-linear time-domain simulation results emphasize the great potential of the proposed scheme in mitigation of inter-area power oscillations according to the considered disturbances. The proposed scheme is simple yet effective in treating the inter-area oscillations appropriately under the considered case studies.

This article presents an inexpensive, efficient, and electrically‐small antenna design that is based on a metamaterial‐inspired structure driven by an electrically‐small semi‐circular loop antenna, which is coaxially‐fed through a finite ground plane. The proposed antenna system is linearly scalable over a wide frequency spectrum. The design details and radiation characteristics of the antenna system at 300, 1580, and 6000 MHz are reported. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1287–1290, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22415