306 research outputs found

    Low Power Analog to Digital Converters in Advanced CMOS Technology Nodes

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    The dissertation presents system and circuit solutions to improve the power efficiency and address high-speed design issues of ADCs in advanced CMOS technologies. For image sensor applications, a high-performance digitizer prototype based on column-parallel single-slope ADC (SS-ADC) topology for readout of a back-illuminated 3D-stacked CMOS image sensor is presented. To address the high power consumption issue in high-speed digital counters, a passing window (PW) based hybrid counter topology is proposed. To address the high column FPN under bright illumination conditions, a double auto-zeroing (AZ) scheme is proposed. The proposed techniques are experimentally verified in a prototype chip designed and fabricated in the TSMC 40 nm low-power CMOS process. The PW technique saves 52.8% of power consumption in the hybrid digital counters. Dark/bright column fixed pattern noise (FPN) of 0.0024%/0.028% is achieved employing the proposed double AZ technique for digital correlated double sampling (CDS). A single-column digitizer consumes total power of 66.8μW and occupies an area of 5.4 µm x 610 µm. For mobile/wireless receiver applications, this dissertation presents a low-power wide-bandwidth multistage noise-shaping (MASH) continuous-time delta-sigma modulator (CT-ΔΣM) employing finite impulse response (FIR) digital-to-analog converters (DACs) and encoder-embedded loop-unrolling (EELU) quantizers. The proposed MASH 1-1-1 topology is a cascade of three single-loop first-order CT-ΔΣM stages, each of which consists of an active-RC integrator, a current-steering DAC, and an EELU quantizer. An FIR filter in the main 1.5-bit DAC improves the modulator’s jitter sensitivity performance. FIR’s effect on the noise transfer function (NTF) of the modulator is compensated in the digital domain thanks to the MASH topology. Instead of employing a conventional analog direct feedback path, a 1.5-bit EELU quantizer based on multiplexing comparator outputs is proposed; this approach is suitable for highspeed operation together with power and area benefits. Fabricated in a 40-nm low-power CMOS technology, the modulator’s prototype achieves a 67.3 dB of signal-to-noise and distortion ratio (SNDR), 68 dB of signal-to-noise ratio (SNR), and 68.2 dB of dynamic range (DR) within 50.5 MHz of bandwidth (BW), while consuming 19 mW of total power (P). The proposed modulator features 161.5 dB of figure-of-merit (FOM), defined as FOM = SNDR + 10 log10 (BW/P)

    FEATURES OF THE MORPHOLOGY OF THE SHEAR FAILURE SURFACES OF COARSE-GRAINED SLIP ZONE SOILS

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    Analyzing the change in the roughness of the shear plane under different particle composition is important to reveal the mesoscopic mechanism of strength change of coarse-grained slip zone soil. Slip zone soils were grouped according to different particle gradations and coarse particle contents for experiments. To collect shear plane coordinate data points, the customized shear plane measurement die was examined in the early stage to measure the shear plane. Then, the measured 3D data points are drawn into a 3D surface map by using the Surfer drawing software to show the actual situation of the shear plane. The shear planes were analyzed from different angles by using box plots and ice crystal flower plots. Finally, the roughness of the shear plane was quantified by the root mean square of the relative undulation (Z2). Findings indicate that the shear plane undulation characteristics of coarse-grained slip zone soil are obviously correlated with the proportion of particles with a size between 5–20 mm. Moreover, whether the gradation is good or poor has a significant effect on the shear plane characteristics. The well-graded shear plane is coarser and more undulated, whereas the poorly graded shear plane is the opposite. As the normal force increases, the undulation and roughness of the shear plane decrease. As the content of coarse particles increases, the roughness of the shear plane increases, and Z2 has a highly positive linear correlation with the coarse particle content

    MURPHY: Relations Matter in Surgical Workflow Analysis

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    Autonomous robotic surgery has advanced significantly based on analysis of visual and temporal cues in surgical workflow, but relational cues from domain knowledge remain under investigation. Complex relations in surgical annotations can be divided into intra- and inter-relations, both valuable to autonomous systems to comprehend surgical workflows. Intra- and inter-relations describe the relevance of various categories within a particular annotation type and the relevance of different annotation types, respectively. This paper aims to systematically investigate the importance of relational cues in surgery. First, we contribute the RLLS12M dataset, a large-scale collection of robotic left lateral sectionectomy (RLLS), by curating 50 videos of 50 patients operated by 5 surgeons and annotating a hierarchical workflow, which consists of 3 inter- and 6 intra-relations, 6 steps, 15 tasks, and 38 activities represented as the triplet of 11 instruments, 8 actions, and 16 objects, totaling 2,113,510 video frames and 12,681,060 annotation entities. Correspondingly, we propose a multi-relation purification hybrid network (MURPHY), which aptly incorporates novel relation modules to augment the feature representation by purifying relational features using the intra- and inter-relations embodied in annotations. The intra-relation module leverages a R-GCN to implant visual features in different graph relations, which are aggregated using a targeted relation purification with affinity information measuring label consistency and feature similarity. The inter-relation module is motivated by attention mechanisms to regularize the influence of relational features based on the hierarchy of annotation types from the domain knowledge. Extensive experimental results on the curated RLLS dataset confirm the effectiveness of our approach, demonstrating that relations matter in surgical workflow analysis

    Protocatechuic acid induces apoptosis in human osteosarcoma cells by regulating P13K/AKT/ROS pathway

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    Previous investigations have demonstrated that protocatechuic acid (PCA) provides anti-tumour properties in different tumour cell types. It does, however, have an unknown cause on osteosarcoma cells. In this investigation, the underlying mechanism of the effect of PCA on osteosarcoma cells (MNNG or HOS) was investigated and established. The viability of the cell was assessed with the MTT test. Acridine orange/ethidium bromide staining and Western blot analysis were conducted for assessment of cell apoptosis. Western blot analysis was identified for cell cycle progression. In addition to establishing the above findings, the Western blot analysis demonstrated that PCA mediated osteosarcoma cellular apoptosis by triggering the apoptotic pathway of Caspase-9. Additionally, we found that PCA considerably stimulated osteosarcoma cell apoptosis and arrest of cell cycle proliferation by controlling a pathway involving P13K/Akt/ROS signalling. In short, we observed that PCA prevented the advancement of osteosarcoma through the stimulation of apoptosis in osteosarcoma cells. The mechanism underlying this study also showed that PCA generated effective anti-tumour activity on osteosarcoma cells by controlling the signalling pathways of P13K/Akt/ROS

    Black holes in Einstein-dilaton-Massive gravity

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    In this paper, we focus on the Einstein-dilaton-Massive (EdM) gravity including the coupling of dilaton scalar field to massive graviton terms, and then derive static and spherically symmetric solutions of dilatonic black holes in four dimensional spacetime. We discover that the dilatonic black hole could possess two horizons (event and cosmological), extreme (Nariai) and naked singularity black holes for the suitably fixed parameters. Moreover, the dilatonic black hole solutions are neither asymptotic flat nor (A)dS in the appearance of coupling of the dilaton field. In addition, we investigate thermodynamic properties of these dilatonic black holes, and check the corresponding first law of black hole thermodynamics. Extending to the EdM gravity in high dimensions, we further obtain the dilatonic black hole solutions in (d+1d+1) dimensional spacetime.Comment: 17 pages, 6 figure

    Optical source profiles of brown carbon in size-resolved particulate matter from typical domestic biofuel burning over Guanzhong Plain, China

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    In this study, both PM2.5 and size-resolved source samples were collected from a "heated kang" and an advanced stove to investigate the optical properties of brown carbon (BrC). The light-absorption coefficient (babs), the absorption Angstrom exponent (AAE), and the mass absorption cross-section (MAC) of both water and methanol-extracted BrC were investigated. The methanol-extracted BrC (BrCmethanol) had higher light absorption than water-extracted BrC (BrCwater). The value of PM2.5 babs of BrCmethanol at 365 nm(b(abs365),methanol) dramatically decreased from 64,669.8Mm(-1) for straw burning in the "heated kang" to 1169.2 Mm(-1) formaize straw briquettes burning in the advanced stove at the same burning rate. The value of PM2.5 MAC for BrCmethanol at 365 nm (MAC(365), methanol) decreased from 1.8 m(2) g(-1) in the "heated kang" to 1.3 m(2) g-1 in the advanced stove. For smoldering burning in the "heated kang", babs365, methanol, MAC365, methanol, and K+ showed a unimodal distribution that peaked at sizes < 0.4 mu m. However, the babs365, methanol and MAC(365), methanol size distributions of the briquette burning in the advanced stove showed a bimodal pattern, with a large peak at sizes < 0.4 mu m and a minor peak in the size range of 4.7-5.8 mu m. The babs365, methanol value for sizes < 0.4 mu m (277.4 Mm(-1)) was only 12.3% compared to those obtained from the "heated kang". The burning rate did not influence the size distribution pattern of either the "heated kang" or the advanced stove. Results from a radiative model show that biomass burning is an important factor for light absorptivity, and the use of an advanced stove can reduce the simple forcing efficiency value by nearly 20% in UV bands compared to the "heated kang". Our results indicate that changing the combustion style from maize straw smoldering to briquette burning in an advanced stove can effectively reduce BrC emissions during heating seasons in rural areas of Guanzhong Plain. (C) 2017 Elsevier B.V. All rights reserved

    Mind's Mirror: Distilling Self-Evaluation Capability and Comprehensive Thinking from Large Language Models

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    Large language models (LLMs) have achieved remarkable advancements in the field of natural language processing. However, the sheer scale and computational demands of these models present formidable challenges when considering their practical deployment in resource-constrained contexts. While techniques such as chain-of-thought (CoT) distillation have displayed promise in distilling LLMs into small language models (SLMs), there is a risk that distilled SLMs may still carry over flawed reasoning or hallucinations inherited from their LLM counterparts. To address these issues, we propose a twofold methodology: First, we introduce a novel method for distilling the self-evaluation capability inherent in LLMs into SLMs, which aims to mitigate the adverse effects of erroneous reasoning and reduce hallucinations. Second, we advocate for a comprehensive distillation process that incorporates multiple distinct chain-of-thought and self-evaluation paradigms and ensures a more holistic and robust knowledge transfer into SLMs. Experiments on three NLP benchmarks demonstrate that our method significantly improves the performance of distilled SLMs and sheds light on the path towards developing smaller models closely aligned with human cognition.Comment: 13 pages, 5 figure
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