Al-doped Ge55Te45 materials are proposed for phase change memory application. Al incorporated in Ge55Te45 increases the crystallization temperature, band gap and 10-year data retention significantly. However, the crys...
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Al-doped Ge55Te45 materials are proposed for phase change memory application. Al incorporated in Ge55Te45 increases the crystallization temperature, band gap and 10-year data retention significantly. However, the crystallization speed of the Al-doped Ge55Te45 material will be lowered by excessive Al doping. The crystallization of the Al-doped Ge55Te45 film is observed to be growth-dominant, beginning with a random formation of spherical crystalline clusters. The 10-year data retention and crystallization speed of Al1Ge55Te45 are 117 degrees C and 5 ns, respectively, which makes the Al1Ge55Te45 a promising candidate for high speed PCM application. The 10-year data retention of 132 degrees C and good cyclic ability of similar to 2 x 10(3) cycles of the Al2Ge55Te45 based PCM have shown its application potential in automotive fields. (C) 2013 AIP Publishing LLC.
In this paper, we propose a differential flatness-based observer for a PEM fuel cell air-feed system. The proposed observer uses the measurements of supply manifold air pressure and compressor mass flow rate in order ...
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ISBN:
(纸本)9783033039629
In this paper, we propose a differential flatness-based observer for a PEM fuel cell air-feed system. The proposed observer uses the measurements of supply manifold air pressure and compressor mass flow rate in order to estimate the oxygen partial pressure, nitrogen partial pressure and the compressor speed. An adaptive-gain Second Order Sliding Mode differentiator based on super-twisting algorithm is designed to estimate the time derivatives of the system outputs when the boundary of higher time derivative is unknown. Then, the states are estimated based on these values. The objective is to minimize the number of embedded sensors in order to get a precise and economic solution. The feasibility and effectiveness of the proposed approach is demonstrated through simulation results obtained from a nonlinear fuel cell system.
This work presents initial experimental results of an adaptive sliding-mode extremum seeker that minimizes the hydrogen consumption in a fuel cell based system. The extremum seeker is based on the classical steepest-d...
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ISBN:
(纸本)9783033039629
This work presents initial experimental results of an adaptive sliding-mode extremum seeker that minimizes the hydrogen consumption in a fuel cell based system. The extremum seeker is based on the classical steepest-descent method, the main challenge being the fact that the gradient of the objective function is unknown. The gradient is estimated by means of a sliding-mode adaptive estimator. The strategy is applied in experimental practical situations in a fuel cell test bench, this allows to asses the performance of the scheme as well as the difficulties that arise in real applications.
This paper presents a 44-channel front-end neural interface for recording both Extracellular Action Potentials (EAPs) and Local Field Potentials (LFPs) with 60 dB dynamic range. With a silicon footprint of only 0.015 ...
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ISBN:
(纸本)9781479914715
This paper presents a 44-channel front-end neural interface for recording both Extracellular Action Potentials (EAPs) and Local Field Potentials (LFPs) with 60 dB dynamic range. With a silicon footprint of only 0.015 mm(2) per recording channel this allows an unprecedented order of magnitude area reduction over state-of-the-art implementations in 0.18 mu m CMOS. This highly compact configuration is achievable by introducing an in-channel Sigma Delta assisted Successive Approximation Register (Sigma Delta-SAR) hybrid data converter integrated into the analogue front-end. A pipelined low complexity FIR filter is distributed across 44-channels to resolve a 10-bit PCM output. The proposed system achieves an input referred noise of 6.41 mu V-rms with a 6 kHz bandwidth and sampled at 12.5 kS/s, with a power consumption of 2.6 mu W per channel.
Hybrid architecture can be more favorable by providing both best of the two types of memory, volatile and persistent types. Since there is no need of power to store the data, it is possible to provide faster booting t...
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ISBN:
(纸本)9789791421195
Hybrid architecture can be more favorable by providing both best of the two types of memory, volatile and persistent types. Since there is no need of power to store the data, it is possible to provide faster booting time from completely off state. However, because of the limited number of writes can be performed on PRAM devices, we need to manage it well in order to get longest lifetime. Our proposed system provides APIs to develop custom wear-level schemes and deploy it easily to the system. We defined APIs specifications which include memory management and protection, to provide further protection to the system from memory attack. We focused on phase-change memory (PCM) as the representation of Persistent RAM (PRAM), since it is the most probable candidate for DRAM replacement. We observed that there are rooms for improvements to elongate PCM lifetime, such as the shared library objects loading to the BPRAM, separation of three memory region in process (i.e. code, data, stack regions), moving rarely modified blocks of RAM to the BPRAM, and also the capability of saving only important states when desired by the application developers.
Photonic Crystal membrane (PCM) resonators can be exploited to perform an arbitrarily adjustable molding of light at the wavelength scale: they can process free-space as well as wave-guided optical modes along a varie...
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ISBN:
(纸本)9781479956029
Photonic Crystal membrane (PCM) resonators can be exploited to perform an arbitrarily adjustable molding of light at the wavelength scale: they can process free-space as well as wave-guided optical modes along a variety of addressing configurations and transfer functions, where the spectral, spatial, polarization, phase, group delay... characteristics can be resolved accurately and adjusted at will. The physics of PCM resonators will be revisited based on simple analytical approaches and intuitive arguments, thus providing direct routes for design rules. Specifically, such desired functionalities as wavelength tuning and beam steering will be emphasized. Practical implementation of these functionalities will be presented in the case of VCSEL devices, where silicon PCM resonators are used as reflectors and are heterogeneously integrated with III-V semiconductor gain material, along a CMOS compatible technological approach.
In this paper, a phase change material (PCM) based heat sink was proposed and its geometry was optimized for heat transfer enhancement. The thermal resistance network between the heat source and the control volume was...
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ISBN:
(纸本)9781479952687
In this paper, a phase change material (PCM) based heat sink was proposed and its geometry was optimized for heat transfer enhancement. The thermal resistance network between the heat source and the control volume was applied to analyze the influence on heat storage performance of the phase change material based heat sink (PCMBHS) and the optimization suggestions were proposed. Besides, the heat storage performance of the optimized fined PCMBHS was examined experimentally. The results showed that the temperature difference of the PCM inside each control volume reduced by 67% and the heat storage rate increased by 14% compared to those of the uniformly fined PCMBHS during the latent heat storage period.
This paper applies the Bianchi-Loubaton-Sirven technique to classification algorithm capable of distinguishing between PCM/FM and SOQPSK-TG. A happy byproduct of the classification algorithm is a reasonably accurate e...
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This paper applies the Bianchi-Loubaton-Sirven technique to classification algorithm capable of distinguishing between PCM/FM and SOQPSK-TG. A happy byproduct of the classification algorithm is a reasonably accurate estimate of the bit rate. The classifier is based on the observation that CPM with an integer modulation index contains harmonics at multiples of the symbol rate. The algorithm is based on the CPM representations of PCM/FM and SOQPSK-TG and leverages the property that applying a g-order nonlinearity to any CPM creates a new CPM with modulation index g times the original modulation index. No prior knowledge of the data is assumed. The technique is applied to distinguish between PCM/FM and SOQPSK-TG. Simulation results show that the classifier works essentially error-free for signal-to-noise ratios above 20 dB and for sufficiently high resolution in the search algorithms required by the maximizations.
In this paper, a modular thermal modelling approach for a water-cooled Proton Exchange Membrane fuel cell (PEM-FC) stack is proposed. The resultant model is based on the heat flux inside the stack and has been validat...
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ISBN:
(纸本)9781479902255
In this paper, a modular thermal modelling approach for a water-cooled Proton Exchange Membrane fuel cell (PEM-FC) stack is proposed. The resultant model is based on the heat flux inside the stack and has been validated in a real test station. Then, a linear model predictive control (MPC) strategy for temperature regulation is designed and tested in simulation with promising results. The proposed MPC controller not only tackles the temperature regulation problem, but also incorporates necessary management constraints for the proper operation of the system in real conditions.
Multi-site photoplethysmography is an optoelectronic technique that measures changes in blood volume associated with cardiac contraction. Photoplethysmogram (PPG) recording enables researchers to study the vascular an...
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ISBN:
(纸本)9781467352321
Multi-site photoplethysmography is an optoelectronic technique that measures changes in blood volume associated with cardiac contraction. Photoplethysmogram (PPG) recording enables researchers to study the vascular and hemodynamic properties of human subjects. Currently, there is no commercial system available in the market to perform multi-channel PPG recording. The measurements can be obtained from fingertips, ear lobes and toes due to their low absorption and high degree of vasculature. The main objective of this project is to develop a suitable data compression algorithm for two-channel simultaneous high resolution wireless PPG recording system. MATLAB software was used during the algorithm development phase to ensure the rapid prototyping. The result showed that delta modulation (DM) is able to compress PPG signals with a compression ratio (CR) up to 16 with an PRMSE of 3.92×10~(-4). This system is expected to be a portable, wearable and battery operated device for clinical applications.
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