Long-term memory formation is a major function of sleep. Based on evidence from neurophysiological and behavioral studies mainly in humans and rodents, we consider the formation of long-term memory ...during sleep as an active systems consolidation process that is embedded in a process of global synaptic downscaling. Repeated neuronal replay of representations originating from the hippocampus during slow-wave sleep leads to a gradual transformation and integration of representations in neocortical networks. We highlight three features of this process: (i) hippocampal replay that, by capturing episodic memory aspects, drives consolidation of both hippocampus-dependent and non-hippocampus-dependent memory; (ii) brain oscillations hallmarking slow-wave and rapid-eye movement sleep that provide mechanisms for regulating both information flow across distant brain networks and local synaptic plasticity; and (iii) qualitative transformations of memories during systems consolidation resulting in abstracted, gist-like representations.
•A sensor-based data-driven scheme using deep learning for RUL estimation.•The bidirectional recurrent neural network is used to increase input information.•A novel bidirectional recurrent neural ...network based autoencoder scheme is proposed.•It shows obvious competitiveness compared with most state-of-art algorithms.
System remaining useful life (RUL) estimation is one of the major prognostic activities in industrial applications. In this paper, we propose a sensor-based data-driven scheme using a deep learning tool and the similarity-based curve matching technique to estimate the RUL of a system. The whole procedure consists of two steps: in the first step, a bidirectional recurrent neural network based autoencoder is trained in an unsupervised way to convert the multi-sensor (high-dimensional) readings collected from historical run-to-failure instances (i.e. multiple units of the same system) to low-dimensional embeddings, which are used to construct the one-dimensional health index (HI) values to reflect various health degradation patterns of the instances. In the second step, the test HI curve obtained from sensor readings collected from an on-line instance is compared with the degradation patterns built in the offline phase using the similarity-based curve matching technique, from which the RUL of the test unit can be estimated at an early stage. The proposed scheme was tested on two publicly available run-to-failure datasets: the turbofan engine datasets (simulation datasets) and the milling datasets (experimental datasets). The prognostic performance of the proposed procedure was directly compared with the existing state-of-art prognostic models in terms of various prognostic metrics on the two datasets respectively. The comparison results demonstrate the competitiveness of the proposed method used for RUL estimation of systems.
We put forward and demonstrate a silicon photonics (SiPh)-based mode division multiplexed (MDM) optical power splitter that supports transverse-electric (TE) single-mode, dual-mode, and triple-mode ...(i.e., TEsub.0, TEsub.1, and TEsub.2). An optical power splitter is needed for optical signal distribution and routing in optical interconnects. However, a traditional optical splitter only divides the power of the input optical signal. This means the same data information is received at all the output ports of the optical splitter. The powers at different output ports may change depending on the splitting ratio of the optical splitter. The main contributions of our proposed optical splitter are: (i) Different data information is received at different output ports of the optical splitter via the utilization of NOMA. By adjusting the power ratios of different channels in the digital domain (i.e., via software control) at the Tx, different channel data information can be received at different output ports of the splitter. It can increase the flexibility of optical signal distribution and routing. (ii) Besides, the proposed optical splitter can support the fundamental TEsub.0 mode and the higher modes TEsub.1, TEsub.2, etc. Supporting mode-division multiplexing and multi-mode operation are important for future optical interconnects since the number of port counts is limited by the chip size. This can significantly increase the capacity besides wavelength division multiplexing (WDM) and spatial division multiplexing (SDM). The integrated SiPh MDM optical power splitter consists of a mode up-conversion section implemented by asymmetric directional couplers (ADCs) and a Y-branch structure for MDM power distribution. Here, we also propose and discuss the use of the Genetic algorithm (GA) for the MDM optical power splitter parameter optimization. Finally, to provide adjustable data rates at different output ports after the MDM optical power splitter, non-orthogonal multiple access—orthogonal frequency division multiplexing (NOMA-OFDM) is also employed. Experimental results validate that, in three modes (TEsub.0, TEsub.1, and TEsub.2), user-1 and user-2 achieve data rates of (user-1: greater than 22 Gbit/s; user-2: greater than 12 Gbit/s) and (user-1: greater than 12 Gbit/s; user-2: 24 Gbit/s), respectively, at power-ratio (PR) = 2.0 or 3.0. Each channel meets the hard-decision forward-error-correction (HD-FEC, i.e., BER = 3.8 × 10sup.−3) threshold. The proposed method allows flexible data rate allocation for multiple users for optical interconnects and system-on-chip networks.
This paper proposes a novel high-gain planar antenna design that consists of conducting metallic disks suspended on air and operates at 1 GHz. The antenna is designed for receiving the unintentional ...electromagnetic emanations generated by one or multiple embedded, "smart" electronic systems. The antenna consists of two layers of slotted conducting metal disks suspended on air and placed above the ground plane using teflon screws. The circular disks are designed to operate in higher order <inline-formula> <tex-math notation="LaTeX">{TM}_{12} </tex-math></inline-formula> mode. The screws' location is the electric field nulls along the disk radius. The upper layer is <inline-formula> <tex-math notation="LaTeX">2 \times 2 </tex-math></inline-formula> array of slotted circular disks electromagnetically coupled by the lower identical disk which is fed directly by a single coaxial feed. The complete fabrication of the antenna is done using aluminum metal sheets and involves no use of the dielectric substrate. The antenna has a peak gain of 19 dBi with impedance bandwidth (<inline-formula> <tex-math notation="LaTeX">S_{11}\le -6 </tex-math></inline-formula> dB) of 6.7%. The simple and cost-effective design can be easily scaled to higher frequencies.
Word embeddings are a powerful machine-learning framework that represents each English word by a vector. The geometric relationship between these vectors captures meaningful semantic relationships ...between the corresponding words. In this paper, we develop a framework to demonstrate how the temporal dynamics of the embedding helps to quantify changes in stereotypes and attitudes toward women and ethnic minorities in the 20th and 21st centuries in the United States. We integrate word embeddings trained on 100 y of text data with the US Census to show that changes in the embedding track closely with demographic and occupation shifts over time. The embedding captures societal shifts—e.g., the women’s movement in the 1960s and Asian immigration into the United States—and also illuminates how specific adjectives and occupations became more closely associated with certain populations over time. Our framework for temporal analysis of word embedding opens up a fruitful intersection between machine learning and quantitative social science.
With embedded devices becoming more pervasive and entrenched in society, it is paramount to keep these systems secure. A threat plaguing these systems consists of software vulnerabilities that cause ...memory corruption, potentially allowing an attacker to breach the device. Software-based countermeasures exist, but suffer from high overhead. In this survey, we investigate whether this could be mitigated using dedicated hardware. Driven by the advancements of open hardware, we focus on implementations for RISC-V, a novel and open architecture tailored for customization. We distinguish between methods validating memory accesses beforehand, obfuscating information necessary for an attack, and detecting memory values corrupted earlier. We compare on qualitative metrics, such as the security coverage and level of transparency, and performance in both software and hardware. Although current implementations do not easily allow for a fair comparison as their evaluation methodologies vary widely, we show that current implementations are suitable to minimize the runtime overhead with a relatively small area overhead. Nevertheless, we identified that further research is still required to mitigate more fine-grained attacks such as intra-object overflows, to integrate into more sophisticated protected execution environments towards resilient systems that are automatically recoverable, and to move towards more harmonized evaluation.
New generation airborne embedded system has deployed Graphical Processing Units (GPUs) to raise processing capability to meet growing computational demands. Comparing with the cloud system, the ...airborne embedded system usually has a fixed application set, but strict real-time constraints. Unfortunately, the inherent GPU scheduler does not consider the application priority, which cannot provide the sufficient real-time capability to the airborne embedded system. To meet timeliness requirements, it is necessary to predict timing behaviors of those applications and design a real-time scheduling policy based on priority and deadline. We therefore propose WAMP<inline-formula><tex-math notation="LaTeX">^2</tex-math> <mml:math><mml:msup><mml:mrow/><mml:mn>2</mml:mn></mml:msup></mml:math><inline-graphic xlink:href="yao-ieq2-3134269.gif"/> </inline-formula>S, a workload-aware GPU performance model based pseudo-preemptive real-time scheduling algorithm for the airborne embedded system. The workload-aware GPU performance model can accurately predict the execution time of an application, which is running concurrently with other applications on GPU. The pseudo-preemptive real-time scheduling algorithm can provide the approximate preemption by dynamically adjusting GPU computing resources for active applications. Unlike previous work on GPU performance model and GPU real-time scheduling, WAMP<inline-formula><tex-math notation="LaTeX">^2</tex-math> <mml:math><mml:msup><mml:mrow/><mml:mn>2</mml:mn></mml:msup></mml:math><inline-graphic xlink:href="yao-ieq3-3134269.gif"/> </inline-formula>S considers the impact of co-executing workload on the execution time estimation and provides a software-only approach for preemption support. In addition, WAMP<inline-formula><tex-math notation="LaTeX">^2</tex-math> <mml:math><mml:msup><mml:mrow/><mml:mn>2</mml:mn></mml:msup></mml:math><inline-graphic xlink:href="yao-ieq4-3134269.gif"/> </inline-formula>S implements a prototype GPU scheduler without any source code analysis. We evaluate the proposed GPU performance model and real-time scheduling algorithm in both simulated and realistic application sets. Experimental results illustrate that WAMP<inline-formula><tex-math notation="LaTeX">^2</tex-math> <mml:math><mml:msup><mml:mrow/><mml:mn>2</mml:mn></mml:msup></mml:math><inline-graphic xlink:href="yao-ieq5-3134269.gif"/> </inline-formula>S can achieve low prediction error and high scheduling success ratio.
Thermal camouflage has been successful in the conductive regime, where thermal metamaterials embedded in a conductive system can manipulate heat conduction inside the bulk. Most reported approaches ...are background-dependent and not applicable to radiative heat emitted from the surface of the system. A coating with engineered emissivity is one option for radiative camouflage, but only when the background has uniform temperature. Here, we propose a strategy for radiative camouflage of external objects on a given background using a structured thermal surface. The device is non-invasive and restores arbitrary background temperature distributions on its top. For many practical candidates of the background material with similar emissivity as the device, the object can thereby be radiatively concealed without a priori knowledge of the host conductivity and temperature. We expect this strategy to meet the demands of anti-detection and thermal radiation manipulation in complex unknown environments and to inspire developments in phononic and photonic thermotronics.
The development of embedded technology directly affects the development of Internet of Things, and the development of artificial intelligence brings great convenience to people's life. Based on this, ...the implementation method of artificial intelligence algorithm in embedded system is studied. Based on embedded system hardware configuration and the embedded system software running algorithm is optimized, simplifying the operation steps of the embedded system, improve the effect of embedded system, to strengthen the research of embedded technology, and increase investment in manpower and material resources in embedded system research, learning western advanced technology, and the embedded technology is applied in the Internet of things, to improve the effect of artificial intelligence algorithm in the application of the embedded system. The experimental results show that the artificial intelligence algorithm is applied to the embedded system to improve the system performance effectively.
Embedded systems operational environment poses tightened and usually conflicted design requirements. Software architects aim at introducing effective tradeoff methods to select the most appropriate ...design solutions to comply with the software specifications of an embedded system. When defining the software architecture for critical embedded systems it is mandatory to balance often conflicting goals to meet the different requirements in terms of resource consumption, schedulability, dependability, and security, among others. This is an engineering problem that can be addressed by employing Multiple-Criteria Decision-Making (MCDM) methods from the operational research domain. This paper combines two of these methods, Analytical Hierarchy Process (AHP) and Technique for Order Preferences by Similarity to Ideal Solution (TOPSIS), to determine the most efficient fault detection design decisions according to relevant metrics. The paper employs two algorithm efficiency metrics: run-time complexity and memory-space complexity. Furthermore, the fault-detection strategy design decisions, Ping/Echo and Heartbeat, were the subjects of this study.
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