142 research outputs found
Non-Debye impedance and relaxation models for dissipative electrochemical capacitors
Electrochemical capacitors are a class of energy devices in which complex
mechanisms of accumulation and dissipation of electric energy take place when
connected to a charging or discharging power system. Reliably modeling their
frequency-domain and time-domain behaviors is crucial for their proper design
and integration in engineering applications, knowing that electrochemical
capacitors in general exhibit anomalous tendency that cannot be adequately
captured with traditional integer-order-based models. In this study we first
review some of the widely used fractional-oder models for the description of
impedance and relaxation functions of dissipative resistive-capacitive system,
namely the Cole-Cole, Davidson-Cole, and Havriliak-Negami models. We then
propose and derive new q-deformed models based on modified evolution equations
for the charge or voltage when the device is discharged into a parallel
resistive load. We verify our results on anomalous spectral impedance response
and time-domain relaxation data for voltage and charge obtained from a
commercial supercapacitor.Comment: 9 pages, 3 figure
ADEPOS: Anomaly Detection based Power Saving for Predictive Maintenance using Edge Computing
In industry 4.0, predictive maintenance(PM) is one of the most important
applications pertaining to the Internet of Things(IoT). Machine learning is
used to predict the possible failure of a machine before the actual event
occurs. However, the main challenges in PM are (a) lack of enough data from
failing machines, and (b) paucity of power and bandwidth to transmit sensor
data to cloud throughout the lifetime of the machine. Alternatively, edge
computing approaches reduce data transmission and consume low energy. In this
paper, we propose Anomaly Detection based Power Saving(ADEPOS) scheme using
approximate computing through the lifetime of the machine. In the beginning of
the machines life, low accuracy computations are used when the machine is
healthy. However, on the detection of anomalies, as time progresses, the system
is switched to higher accuracy modes. We show using the NASA bearing dataset
that using ADEPOS, we need 8.8X less neurons on average and based on
post-layout results, the resultant energy savings are 6.4 to 6.65XComment: Submitted to ASP-DAC 2019, Japa
Boolean Compressive Sensing: An Approximate Trust Region reconstruction
In this paper, we propose a direct nonlinear optimization method to solve the Boolean Compressive Sensing (BCS) problem for large signals when sparsity level is unknown. While traditional CS results from linear Algebra, BCS, is given by logical operation in the Boolean workspace. To overcome this inconvenience, we relax the problem in an equivalent formulation in the Real workspace using appropriate modeling as a first step. Thereafter we turn out the problem in an unconstrained form that can be solved directly by nonlinear optimization method called Trust Region methods (TRM). Our solution is based on an Approximate version of (TRM). Numerical results are presented to sustain efficiency of our proposal
A simple thermodynamical witness showing universality of macroscopic entanglement
We show that if the ground state entanglement exceeds the total entropy of a
given system, then this system is in an entangled state. This is a universal
entanglement witness that applies to any physical system and yields a
temperature below which we are certain to find some entanglement. Our witness
is then applied to generic bosonic and fermionic many body systems to derive
the corresponding "critical" temperatures that have a very broad validity.Comment: 3 pages, Torun conference, June 25-28, 200
Effects of acorn storage duration and parental tree on emergence and physiological status of Cork oak ( Quercus suber
PCA-Aided precoding for correlated MIMO broadcast channels
In this paper, we propose an efficient precoding solution for a correlated Multi-Input Multi-Output (MIMO) broadcast channels. Indeed, we apply the principal component analysis (PCA) to uncorrelate (whiten) the channel prior to codeword selection. As such, the channel state information at the transmitter (CSIT), picked up through finite-rate feedback, corresponds to the uncorrelated channel version. Thus, the optimality of the approach. The simulation results compared with conventional MIMO precoders for various levels of spatial correlation as well as different receive antenna settings, show that the proposed scheme provides greater system performance enhancement in terms of sum rate
Does franchising create value? An analysis of the financial performance of US public restaurant firms
Author's OriginalIt is commonly believed that the franchising method of distribution provides strategic and operational benefits to the companies that adopt it. These benefits should result in superior financial performance as compared to that of firms that do not use franchising. Yet, the empirical evidence of the effects of franchising on financial performance is sparse and mixed. The purpose of this paper is to further examine the empirical evidence of the impact of franchising on a firm’s financial performance by using performance metrics (Economic Value Added and Market Value Added) that are extensively used in corporate finance. This study focuses on the US public restaurant sector. The results provide some evidence that franchising firms create more market and economic value than do non-franchising firms.
A revised version of this paper has since been published in the International Journal of Hospitality and Tourism Administration. Please use this version in your citations.Aliouche, E. & Schlentrich, U. (2009). Does Franchising Create Value? An Analysis of the Financial Performance of US Public Restaurant Firms. International Journal of Hospitality & Tourism Administration, 10(2), 93-10
EM modelling of arbitrary shaped anisotropic dielectric objects using an efficient 3D leapfrog scheme on unstructured meshes
The standard Yee algorithm is widely used in computational electromagnetics because of its simplicity and divergence free nature. A generalization of the classical Yee scheme to 3D unstructured meshes is adopted, based on the use of a Delaunay primal mesh and its high quality Voronoi dual. This allows the problem of accuracy losses, which are normally associated with the use of the standard Yee scheme and a staircased representation of curved material interfaces, to be circumvented. The 3D dual mesh leapfrog-scheme which is presented has the ability to model both electric and magnetic anisotropic lossy materials. This approach enables the modelling of problems, of current practical interest, involving structured composites and metamaterials
Kinetin riboside and its ProTides activate the Parkinson's disease associated PTEN-induced putative kinase 1 (PINK1) independent of mitochondrial depolarization
Since loss of function mutations of PINK1 lead to early-onset Parkinson’s disease, there has been growing interest in the discovery of small molecules that amplify the kinase activity of PINK1. We herein report the design, synthesis, serum stability and hydrolysis of four kinetin riboside ProTides. These ProTides, along with kinetin riboside, activated PINK1 in cells independent of mitochondrial depolarization. This highlights the potential of modified nucleosides and their phosphate prodrugs as treatments for neurodegenerative diseases
Interfacial damage in biopolymer composites reinforced using hemp fibres: Finite element simulation and experimental investigation
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