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Nature Communications May 2019Analog signal processors have attracted a tremendous amount of attention recently, as they potentially offer much faster operation and lower power consumption than their...
Analog signal processors have attracted a tremendous amount of attention recently, as they potentially offer much faster operation and lower power consumption than their digital versions. Yet, they are not preferable for large scale applications due to the considerable observational errors caused by their excessive sensitivity to environmental and structural variations. Here, we demonstrate both theoretically and experimentally the unique relevance of topological insulators for alleviating the unreliability of analog signal processors. In particular, we achieve an important signal processing task, namely resolution of linear differential equations, in an analog system that is protected by topology against large levels of disorder and geometrical perturbations. We believe that our strategy opens up large perspectives for a new generation of robust all-optical analog signal processors, which can now not only perform ultrafast, high-throughput, and power efficient signal processing tasks, but also compete with their digital counterparts in terms of reliability and flexibility.
PubMed: 31053711
DOI: 10.1038/s41467-019-10086-3 -
Sensors (Basel, Switzerland) Sep 2022The TrustZone technology is incorporated in a majority of recent ARM Cortex A and Cortex M processors widely deployed in the IoT world. Security critical code execution...
The TrustZone technology is incorporated in a majority of recent ARM Cortex A and Cortex M processors widely deployed in the IoT world. Security critical code execution inside a so-called secure world is isolated from the rest of the application execution within a normal world. It provides hardware-isolated area called a trusted execution environment (TEE) in the processor for sensitive data and code. This paper demonstrates a vulnerability in the secure world in the form of a cross-world, secure world to normal world, covert channel. Performance counters or Performance Monitoring Unit (PMU) events are used to convey the information from the secure world to the normal world. An encoding program generates appropriate PMU event footprint given a secret . A corresponding decoding program reads the PMU footprint and infers using machine learning (ML). The machine learning model can be trained entirely from the data collected from the PMU in user space. Lack of synchronization between PMU start and PMU read adds noise to the encoding/decoding ML models. In order to account for this noise, this study proposes three different synchronization capabilities between the client and trusted applications in the covert channel. These are synchronous, semi-synchronous, and asynchronous. Previously proposed PMU based covert channels deploy L1 and LLC cache PMU events. The latency of these events tends to be 100-1000 cycles limiting the bandwidth of these covert channels. We propose to use microarchitecture level events with latency of 10-100 cycles captured through PMU for covert channel encoding leading to a potential 100× higher bandwidth. This study conducts a series of experiments to evaluate the proposed covert channels under various synchronization models on a TrustZone supported Cortex-A processor using OP-TEE framework. As stated earlier, switch from signaling based on PMU cache events to PMU microarchitectural events leads to approximately 15× higher covert channel bandwidth. This proposed finer-grained microarchitecture event encoding covert channel can achieve throughput of the order of 11 Kbits/s as opposed to previous work's throughput of the order of 760 bits/s.
Topics: Computers; Humans
PubMed: 36236456
DOI: 10.3390/s22197354 -
Frontiers in Microbiology 2015In this review we stress the differences between eukaryotes and bacteria with respect to their different cell cycles, replication mechanisms and genome organizations.... (Review)
Review
In this review we stress the differences between eukaryotes and bacteria with respect to their different cell cycles, replication mechanisms and genome organizations. One of the most basic and underappreciated differences is that a bacterial chromosome uses only one ori while eukaryotic chromosome uses multiple oris. Consequently, eukaryotic oris work redundantly in a cell cycle divided into separate phases: First inactive replication proteins assemble on eukaryotic oris, and then they await conditions (in the separate "S-phase") that activate only the ori-bound and pre-assembled replication proteins. S-phase activation (without re-assembly) ensures that a eukaryotic ori "fires" (starts replication) only once and that each chromosome consistently duplicates only once per cell cycle. This precise chromosome duplication does not require precise multiple ori firing in S-phase. A eukaryotic ori can fire early, late or not at all. The single bacterial ori has no such margin for error and a comparable imprecision is lethal. Single ori usage is not more primitive; it is a totally different strategy that distinguishes bacteria. We further argue that strong evolutionary pressures created more sophisticated single ori systems because bacteria experience extreme and rapidly changing conditions. A bacterial ori must rapidly receive and process much information in "real-time" and not just in "cell cycle time." This redefinition of bacterial oris as centralized information processors makes at least two important predictions: First that bacterial oris use many and yet to be discovered control mechanisms and second that evolutionarily distinct bacteria will use many very distinct control mechanisms. We review recent literature that supports both predictions. We will highlight three key examples and describe how negative-feedback, phospho-relay, and chromosome-partitioning systems act to regulate chromosome replication. We also suggest future studies and discuss using replication proteins as novel antibiotic targets.
PubMed: 26136739
DOI: 10.3389/fmicb.2015.00610 -
International Journal of Audiology Feb 2020This study evaluated the outcomes of the Oticon Medical Neuro Zti cochlear implant and the Neuro 2 sound processor. Neuro One users were upgraded to Neuro 2....
This study evaluated the outcomes of the Oticon Medical Neuro Zti cochlear implant and the Neuro 2 sound processor. Neuro One users were upgraded to Neuro 2. Monosyllabic word identification was evaluated in adults with Neuro One after ≥5 months, with Neuro 2 at upgrade, and with Neuro 2 after 3 months. Self-reported listening ability, satisfaction, and usability were measured in adults and children. Participants were 44 adults and 26 children. Speech identification scores in quiet and noise were 58% and 45% with Neuro One and 67% and 55% with Neuro 2 after 3 months, respectively. Hearing impairment duration and number of active electrodes significantly predicted speech identification in noise with Neuro 2. Significantly higher questionnaire ratings were obtained for Neuro 2 than Neuro One regarding listening ability in complex listening situations, comfort and music, as well as nine aspects of satisfaction and usability. This study demonstrates the clinical superiority of the Neuro 2 sound processor over Neuro One in terms of speech identification in quiet and in noise and reported patient benefit and satisfaction. Given the study design, sources of improvement may include factors unrelated to the sound processor itself.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Cochlear Implantation; Cochlear Implants; Female; France; Hearing Loss; Humans; Male; Middle Aged; Noise; Patient Satisfaction; Speech Perception; Speech Reception Threshold Test; Treatment Outcome; Young Adult
PubMed: 31584300
DOI: 10.1080/14992027.2019.1671616 -
Sensors (Basel, Switzerland) Mar 2022The rapid evolution of Internet of Things (IoT) applications, such as e-health and the smart ecosystem, has resulted in the emergence of numerous security flaws....
The rapid evolution of Internet of Things (IoT) applications, such as e-health and the smart ecosystem, has resulted in the emergence of numerous security flaws. Therefore, security protocols must be implemented among IoT network nodes to resist the majority of the emerging threats. As a result, IoT devices must adopt cryptographic algorithms such as public-key encryption and decryption. The cryptographic algorithms are computationally more complicated to be efficiently implemented on IoT devices due to their limited computing resources. The core operation of most cryptographic algorithms is the finite field multiplication operation, and concise implementation of this operation will have a significant impact on the cryptographic algorithm's entire implementation. As a result, this paper mainly concentrates on developing a compact and efficient word-based serial-in/serial-out finite field multiplier suitable for usage in IoT devices with limited resources. The proposed multiplier structure is simple to implement in VLSI technology due to its modularity and regularity. The suggested structure is derived from a formal and systematic technique for mapping regular iterative algorithms onto processor arrays. The proposed methodology allows for control of the processor array workload and the workload of each processing element. Managing processor word size allows for control of system latency, area, and consumed energy. The ASIC experimental results indicate that the proposed processor structure reduces area and energy consumption by factors reaching up to 97.7% and 99.2%, respectively.
PubMed: 35336260
DOI: 10.3390/s22062090 -
Bioinformatics (Oxford, England) Dec 2019Light microscopes can now capture data in five dimensions at very high frame rates producing terabytes of data per experiment. Five-dimensional data has three spatial...
SUMMARY
Light microscopes can now capture data in five dimensions at very high frame rates producing terabytes of data per experiment. Five-dimensional data has three spatial dimensions (x, y, z), multiple channels (λ) and time (t). Current tools are prohibitively time consuming and do not efficiently utilize available hardware. The hydra image processor (HIP) is a new library providing hardware-accelerated image processing accessible from interpreted languages including MATLAB and Python. HIP automatically distributes data/computation across system and video RAM allowing hardware-accelerated processing of arbitrarily large images. HIP also partitions compute tasks optimally across multiple GPUs. HIP includes a new kernel renormalization reducing boundary effects associated with widely used padding approaches.
AVAILABILITY AND IMPLEMENTATION
HIP is free and open source software released under the BSD 3-Clause License. Source code and compiled binary files will be maintained on http://www.hydraimageprocessor.com. A comprehensive description of all MATLAB and Python interfaces and user documents are provided. HIP includes GPU-accelerated support for most common image processing operations in 2-D and 3-D and is easily extensible. HIP uses the NVIDIA CUDA interface to access the GPU. CUDA is well supported on Windows and Linux with macOS support in the future.
Topics: Algorithms; Computers; Gene Library; Software
PubMed: 31240306
DOI: 10.1093/bioinformatics/btz523 -
Science Advances Nov 2021A quantum processor to import, process, and export optical quantum states is a common core technology enabling various photonic quantum information processing. However,...
A quantum processor to import, process, and export optical quantum states is a common core technology enabling various photonic quantum information processing. However, there has been no photonic processor that is simultaneously universal, scalable, and programmable. Here, we report on an original loop-based single-mode versatile photonic quantum processor that is designed to be universal, scalable, and programmable. Our processor can perform arbitrarily many steps of programmable quantum operations on a given single-mode optical quantum state by time-domain processing in a dynamically controlled loop-based optical circuit. We use this processor to demonstrate programmable single-mode Gaussian gates and multistep squeezing gates. In addition, we prove that the processor can perform universal quantum operations by injecting appropriate ancillary states and also be straightforwardly extended to a multimode processor. These results show that our processor is programmable, scalable, and potentially universal, leading to be suitable for general-purpose applications.
PubMed: 34767450
DOI: 10.1126/sciadv.abj6624 -
Physics in Medicine and Biology Feb 2021For positron emission tomography (PET) online data acquisition, a centralized coincidence processor (CCP) with single-thread data processing has been used to select...
For positron emission tomography (PET) online data acquisition, a centralized coincidence processor (CCP) with single-thread data processing has been used to select coincidence events for many PET scanners. A CCP has the advantages of highly integrated circuit, compact connection between detector front-end and system electronics and centralized control of data process and decision making. However, it also has the drawbacks of data process delay, difficulty in handling very high count-rates of single and coincidence events and complicated algorithms to implement. These problems are exacerbated when implementing a CCP on a field-programable-gate-array (FPGA) due to increased routing congestion and reduced data throughput. Industry companies have applied non-centralized or distributed data processing to solve these problems, but those solutions remain either proprietary or lack full disclosure of technical details that make the techniques unclear and difficult to adapt for most research communities. In this study, we investigated the use of a set of distributed coincidence processors (DCP) that can address the CCP problems and be implemented relatively easily. Each coincidence processor exclusively connects one detector pair and selects coincidence events from this detector pair only, which breaks a centralized coincidence process to a collection of independent and parallel processes. DCP can significantly minimize the data process delay, maximize count-rates of coincidence events and simplify implementation by implementing a single coincidence processor with one detector pair and replicating it to the rest. A prototype DCP with 42 coincidence processors was implemented on an off-the-shelf FPGA development board for a small PET with 12 detectors configured with 42 detector pairs. DCP performances were tested with both pulsed signals and gamma ray interactions. There was no coincidence data loss up to the detector's maximum singles count-rate (250 k s). Approximately 1.2 k registers were utilized for each coincidence processor and the FPGA resource utilization was proportional to the number of coincidence processors. Coincidence timing spectra showed the results from accurately acquired coincidence events. In conclusion: complementary to CCP, DCP can provide high count-rate capability, with a simplified algorithm for implementation and potentially a practical solution for online acquisition of a PET with a larger number of detector pairs or for ultrahigh-throughput imaging.
Topics: Algorithms; Gamma Rays; Humans; Image Processing, Computer-Assisted; Positron-Emission Tomography; Software
PubMed: 33590827
DOI: 10.1088/1361-6560/abde85 -
European Archives of... Oct 2022The Vibrant Soundbridge (VSB) was introduced in 1996, and the fourth generation of the audio processor recently released. This clinical study evaluates the audiological...
PURPOSE
The Vibrant Soundbridge (VSB) was introduced in 1996, and the fourth generation of the audio processor recently released. This clinical study evaluates the audiological performance and subjective satisfaction of the new SAMBA 2 audio processor compared to its predecessor, SAMBA.
METHOD
Fifteen VSB users tested both audio processors for approximately 3 weeks. Air conduction and bone conduction thresholds and unaided and aided sound field thresholds were measured with both devices. Speech performance in quiet (Freiburg monosyllables) and noise (OLSA) was evaluated as well as subjective listening effort (ACALES) and questionnaire outcomes (SSQ12 and APSQ). In addition, data from 16 subjects with normal hearing were gathered on sound field tests and ACALES.
RESULTS
Both audio processors showed substantial improvement compared to the unaided condition. The SAMBA and SAMBA 2 had comparable performance in sound filed thresholds, while the SAMBA 2 was significantly better in speech in quiet, speech in noise, reduced listening effort, and improved subjective satisfaction compared with the SAMBA.
CONCLUSION
The SAMBA 2 audio processor, compared to its predecessor SAMBA, offers improved performance throughout the parameters investigated in this study. Patients with a VSB implant would benefit from an upgrade to SAMBA 2.
Topics: Bone Conduction; Hearing; Hearing Aids; Humans; Ossicular Prosthesis; Speech Perception
PubMed: 34874465
DOI: 10.1007/s00405-021-07207-4 -
Journal of Clinical Medicine Dec 2020The islet purification step in clinical islet isolation is important for minimizing the risks associated with intraportal infusion. Continuous density gradient with a... (Review)
Review
The islet purification step in clinical islet isolation is important for minimizing the risks associated with intraportal infusion. Continuous density gradient with a COBE 2991 cell processor is commonly used for clinical islet purification. However, the high shear force involved in the purification method using the COBE 2991 cell processor causes mechanical damage to the islets. We and other groups have shown human/porcine islet purification using large cylindrical plastic bottles. Shear stress can be minimized or eliminated using large cylindrical plastic bottles because the bottles do not have a narrow segment and no centrifugation is required during tissue loading and the collection processes of islet purification. This review describes current advances in islet purification from large mammals and humans using a COBE 2991 cell processor versus large cylindrical plastic bottles.
PubMed: 33374512
DOI: 10.3390/jcm10010010