Errors in data transmission cannot be known directly when the data transmission process is fulfilled, but error is often prevalent in data transmission. Faulty or missing frames or bits are standard errors and to cont...
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This paper introduces a fast algorithm for simultaneous inversion and determinant computation of small sized matrices in the context of fully Polarimetric Synthetic Aperture Radar (PolSAR) image processing and analysi...
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Improve of the overall network efficiency between source and destination relay selection and interference free communication is important criteria in WSN. In this paper we are proposing SON based algorithm capable of ...
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We discuss a noninvasive technique to detect glucose changes with enhanced sensitivity based on parity-time (PT) symmetry. We detect glucose level changes within the skin by measuring the frequency shift in the electr...
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We discuss a noninvasive technique to detect glucose changes with enhanced sensitivity based on parity-time (PT) symmetry. We detect glucose level changes within the skin by measuring the frequency shift in the electromagnetic resonance induced within a PT-symmetric system that sandwiches the tissue sample under analysis. Even though the sample itself is lossy, and therefore, resonances would be damped, the introduction of balanced gain and loss enables an efficient sensing mechanism that bypasses the conventional limitations of passive sensing schemes. Our results indicate that the resonance shift can be made fairly linear with respect to the glucose concentration variations, and the expected accuracy is large. We also investigate a realistic system to implement the noninvasive PT-symmetric glucose sensor using loop antennas and negative impedance converters, exploring its sensitivity with respect to design errors and disorder.
This work investigates the use of meta-learning for optimization tasks when a classic operational research problem (flowshop) is considered at the base level. It involves sequencing a set of jobs to be processed by ma...
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This work investigates the use of meta-learning for optimization tasks when a classic operational research problem (flowshop) is considered at the base level. It involves sequencing a set of jobs to be processed by machines in series aiming to minimize the time spent. There are various algorithms or metaheuristics proposed to solve flowshop instances and the choice of the best one usually demands time and resources. Meta-learning applied to algorithm recommendation can simulate specialists' choices as it provides a mapping between the problem characteristics (called meta-features) and the algorithm performance. This work proposes an approach for knowledge discovery operating on the performance of four metaheuristics (Hill Climbing, Tabu Search, Simulated Annealing, and Iterated Local Search) while solving several flowshop instances. Besides recommending the best metaheuristic for each instance, the proposed approach can also recommend well suited parameters values using an Irace-based training process. Despite the possibility of using complex meta-features and powerful machine learning technique, the first experiments have been conducted using simple low and high-level meta-features and a classic machine learning model called Classification and Regression Trees (CART) for the recommendation. Results show that the proposed approach is promising as the induced rules indicate that some metaheuristic parameters are preferable. Nevertheless, regarding the algorithm recommendation there is a lot of room for improvement.
We present our recent results in the area of nonlinear nonreciprocal devices, including isolators and circulators. We show that the nonlinear isolators based on single Fano resonators are subject to a fundamental trad...
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Nonlinear isolators have attracted significant attention for their ability to break reciprocity and provide isolation without the need of an external bias. A popular approach for the design of such devices is based on...
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Nonlinear isolators have attracted significant attention for their ability to break reciprocity and provide isolation without the need of an external bias. A popular approach for the design of such devices is based on Fano resonators, which, due to their sharp frequency response, can lead to very large isolation for moderate input intensities. Here, we show that, independent of their specific implementation, these devices are subject to fundamental bounds on the transmission coefficient in the forward direction versus their quality factor, input power, and nonreciprocal intensity range. Our analysis quantifies a general tradeoff between forward transmission and these metrics, stemming directly from time-reversal symmetry, and that unitary transmission is only possible for vanishing nonreciprocity. Our results also shed light on the operation of resonant nonlinear isolators, reveal their fundamental limitations, and provide indications on how it is possible to design nonlinear isolators with optimal performance.
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