69 research outputs found
Enhanced super-Heisenberg scaling precision by nonlinear coupling and postselection
In quantum precision metrology, the famous result of Heisenberg limit scaling
as (with the number of probes) can be surpassed by considering
nonlinear coupling measurement. In this work, we consider the most
practice-relevant quadratic nonlinear coupling and show that the metrological
precision can be enhanced from the super-Heisenberg scaling
to , by simply employing a pre- and post-selection (PPS) technique, but
not using any expensive quantum resources such as quantum entangled state of
probes.Comment: 6 pages, 4 figure
Quantum-coherence-free precision metrology by means of difference-signal amplification
The novel weak-value-amplification (WVA) scheme of precision metrology is
deeply rooted in the quantum nature of destructive interference between the
pre- and post-selection states. And, an alternative version, termed as joint
WVA (JWVA), which employs the difference-signal from the post-selection
accepted and rejected results, has been found possible to achieve even better
sensitivity (two orders of magnitude higher) under some technical limitations
(e.g. misalignment errors). In this work, after erasing the quantum coherence,
we analyze the difference-signal amplification (DSA) technique, which serves as
a classical counterpart of the JWVA, and show that similar amplification effect
can be achieved. We obtain a simple expression for the amplified signal, carry
out characterization of precision, and point out the optimal working regime. We
also discuss how to implement the post-selection of a classical mixed state.
The proposed classical DSA technique holds similar technical advantages of the
JWVA and may find interesting applications in practice.Comment: 7pages, 5 figures. arXiv admin note: text overlap with
arXiv:2207.0366
A General-Purpose Transferable Predictor for Neural Architecture Search
Understanding and modelling the performance of neural architectures is key to
Neural Architecture Search (NAS). Performance predictors have seen widespread
use in low-cost NAS and achieve high ranking correlations between predicted and
ground truth performance in several NAS benchmarks. However, existing
predictors are often designed based on network encodings specific to a
predefined search space and are therefore not generalizable to other search
spaces or new architecture families. In this paper, we propose a
general-purpose neural predictor for NAS that can transfer across search
spaces, by representing any given candidate Convolutional Neural Network (CNN)
with a Computation Graph (CG) that consists of primitive operators. We further
combine our CG network representation with Contrastive Learning (CL) and
propose a graph representation learning procedure that leverages the structural
information of unlabeled architectures from multiple families to train CG
embeddings for our performance predictor. Experimental results on
NAS-Bench-101, 201 and 301 demonstrate the efficacy of our scheme as we achieve
strong positive Spearman Rank Correlation Coefficient (SRCC) on every search
space, outperforming several Zero-Cost Proxies, including Synflow and Jacov,
which are also generalizable predictors across search spaces. Moreover, when
using our proposed general-purpose predictor in an evolutionary neural
architecture search algorithm, we can find high-performance architectures on
NAS-Bench-101 and find a MobileNetV3 architecture that attains 79.2% top-1
accuracy on ImageNet.Comment: Accepted to SDM2023; version includes supplementary material; 12
Pages, 3 Figures, 6 Table
AIO-P: Expanding Neural Performance Predictors Beyond Image Classification
Evaluating neural network performance is critical to deep neural network
design but a costly procedure. Neural predictors provide an efficient solution
by treating architectures as samples and learning to estimate their performance
on a given task. However, existing predictors are task-dependent, predominantly
estimating neural network performance on image classification benchmarks. They
are also search-space dependent; each predictor is designed to make predictions
for a specific architecture search space with predefined topologies and set of
operations. In this paper, we propose a novel All-in-One Predictor (AIO-P),
which aims to pretrain neural predictors on architecture examples from
multiple, separate computer vision (CV) task domains and multiple architecture
spaces, and then transfer to unseen downstream CV tasks or neural
architectures. We describe our proposed techniques for general graph
representation, efficient predictor pretraining and knowledge infusion
techniques, as well as methods to transfer to downstream tasks/spaces.
Extensive experimental results show that AIO-P can achieve Mean Absolute Error
(MAE) and Spearman's Rank Correlation (SRCC) below 1% and above 0.5,
respectively, on a breadth of target downstream CV tasks with or without
fine-tuning, outperforming a number of baselines. Moreover, AIO-P can directly
transfer to new architectures not seen during training, accurately rank them
and serve as an effective performance estimator when paired with an algorithm
designed to preserve performance while reducing FLOPs.Comment: AAAI 2023 Oral Presentation; version includes supplementary material;
16 Pages, 4 Figures, 22 Table
GENNAPE: Towards Generalized Neural Architecture Performance Estimators
Predicting neural architecture performance is a challenging task and is
crucial to neural architecture design and search. Existing approaches either
rely on neural performance predictors which are limited to modeling
architectures in a predefined design space involving specific sets of operators
and connection rules, and cannot generalize to unseen architectures, or resort
to zero-cost proxies which are not always accurate. In this paper, we propose
GENNAPE, a Generalized Neural Architecture Performance Estimator, which is
pretrained on open neural architecture benchmarks, and aims to generalize to
completely unseen architectures through combined innovations in network
representation, contrastive pretraining, and fuzzy clustering-based predictor
ensemble. Specifically, GENNAPE represents a given neural network as a
Computation Graph (CG) of atomic operations which can model an arbitrary
architecture. It first learns a graph encoder via Contrastive Learning to
encourage network separation by topological features, and then trains multiple
predictor heads, which are soft-aggregated according to the fuzzy membership of
a neural network. Experiments show that GENNAPE pretrained on NAS-Bench-101 can
achieve superior transferability to 5 different public neural network
benchmarks, including NAS-Bench-201, NAS-Bench-301, MobileNet and ResNet
families under no or minimum fine-tuning. We further introduce 3 challenging
newly labelled neural network benchmarks: HiAML, Inception and Two-Path, which
can concentrate in narrow accuracy ranges. Extensive experiments show that
GENNAPE can correctly discern high-performance architectures in these families.
Finally, when paired with a search algorithm, GENNAPE can find architectures
that improve accuracy while reducing FLOPs on three families.Comment: AAAI 2023 Oral Presentation; includes supplementary materials with
more details on introduced benchmarks; 14 Pages, 6 Figures, 10 Table
Guests mediated supramolecule-modified gold nanoparticles network for mimic enzyme application
1434-1441Supramolecules mediated porous metal nanostructures are meaningful materials because of their specific properties and wide range of applications. Here, we describe a general and simple strategy for building Au-networks based on the guest-induced 3D assembly of Au nanoparticles (Au-NPs) resulted in host-guest interaction resolved sulfonatocalix[4]arene (pSC4)-modified Au-NPs aggregate. The diverse guest molecules induced different porous network structures resulting in their different oxidize ability toward glucose. Among three different kinds of guest, hexamethylenediamine-pSC4-Au-NPs have high sensitivity, wide linear range and good stability. By surface characterization and calculating the electrochemical properties of the Au-NPs networks modified glassy carbon electrodes, the giving Au-NPs network reveals good porosity, high surface areas and increased conductance and electron transfer for the electrocatalysis. The synthesized nano-structures afford fast transport of glucose and ensure contact with a larger reaction surface due to high surface area. The fabricated sensor provides a platform for developing a more stable and efficient glucose sensor based on supramolecules mediated Au-NPs networks
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