5,628 research outputs found
Demonstration of Deutsch's Algorithm on a Stable Linear-Optical Quantum Computer
We report an experimental demonstration of quantum Deutsch's algorithm by
using linear-optical system. By employing photon's polarization and spatial
modes, we implement all balanced and constant functions for quantum computer.
The experimental system is very stable and the experimental data are excellent
in accordance with the theoretical results.Comment: 7 pages, 4 figure
Hybrid Artificial Bee Colony Algorithm and Particle Swarm Search for Global Optimization
Artificial bee colony (ABC) algorithm is one of the most recent swarm intelligence based algorithms, which has been shown to be competitive to other population-based algorithms. However, there is still an insufficiency in ABC regarding its solution search equation, which is good at exploration but poor at exploitation. To overcome this problem, we propose a novel artificial bee colony algorithm based on particle swarm search mechanism. In this algorithm, for improving the convergence speed, the initial population is generated by using good point set theory rather than random selection firstly. Secondly, in order to enhance the exploitation ability, the employed bee, onlookers, and scouts utilize the mechanism of PSO to search new candidate solutions. Finally, for further improving the searching ability, the chaotic search operator is adopted in the best solution of the current iteration. Our algorithm is tested on some well-known benchmark functions and compared with other algorithms. Results show that our algorithm has good performance
AdvMIL: Adversarial Multiple Instance Learning for the Survival Analysis on Whole-Slide Images
The survival analysis on histological whole-slide images (WSIs) is one of the
most important means to estimate patient prognosis. Although many
weakly-supervised deep learning models have been developed for gigapixel WSIs,
their potential is generally restricted by classical survival analysis rules
and fully-supervision requirements. As a result, these models provide patients
only with a completely-certain point estimation of time-to-event, and they
could only learn from the well-annotated WSI data currently at a small scale.
To tackle these problems, we propose a novel adversarial multiple instance
learning (AdvMIL) framework. This framework is based on adversarial
time-to-event modeling, and it integrates the multiple instance learning (MIL)
that is much necessary for WSI representation learning. It is a plug-and-play
one, so that most existing WSI-based models with embedding-level MIL networks
can be easily upgraded by applying this framework, gaining the improved ability
of survival distribution estimation and semi-supervised learning. Our extensive
experiments show that AdvMIL could not only bring performance improvement to
mainstream WSI models at a relatively low computational cost, but also enable
these models to learn from unlabeled data with semi-supervised learning. Our
AdvMIL framework could promote the research of time-to-event modeling in
computational pathology with its novel paradigm of adversarial MIL.Comment: 13 pages, 10 figures, 8 table
Pseudo-Bag Mixup Augmentation for Multiple Instance Learning Based Whole Slide Image Classification
Given the special situation of modeling gigapixel images, multiple instance
learning (MIL) has become one of the most important frameworks for Whole Slide
Image (WSI) classification. In current practice, most MIL networks often face
two unavoidable problems in training: i) insufficient WSI data, and ii) the
data memorization nature inherent in neural networks. These problems may hinder
MIL models from adequate and efficient training, suppressing the continuous
performance promotion of classification models on WSIs. Inspired by the basic
idea of Mixup, this paper proposes a Pseudo-bag Mixup (PseMix) data
augmentation scheme to improve the training of MIL models. This scheme
generalizes the Mixup strategy for general images to special WSIs via
pseudo-bags so as to be applied in MIL-based WSI classification. Cooperated by
pseudo-bags, our PseMix fulfills the critical size alignment and semantic
alignment in Mixup strategy. Moreover, it is designed as an efficient and
decoupled method adaptive to MIL, neither involving time-consuming operations
nor relying on MIL model predictions. Comparative experiments and ablation
studies are specially designed to evaluate the effectiveness and advantages of
our PseMix. Test results show that PseMix could often improve the performance
of MIL networks in WSI classification. Besides, it could also boost the
generalization capacity of MIL models, and promote their robustness to patch
occlusion and noisy labels. Our source code is available at
https://github.com/liupei101/PseMix.Comment: 10 pages, 6 figures, 8 table
Separation and Purification of Two Flavone Glucuronides from Erigeron multiradiatus (Lindl.) Benth with Macroporous Resins
Scutellarein-7-O-β-D-glucuronide (SG) and apigenin-7-O-β-D-glucuronide (AG) are two major bioactive constituents with known pharmacological effects in Erigeron multiradiatus. In this study, a simple method for preparative separation of the two flavone glucuronides was established with macroporous resins. The performance and adsorption characteristics of eight macroporous resins including AB-8, HPD100, HPD450, HPD600, D100, D101, D141, and D160 have been evaluated. The results confirmed that D141 resin offered the best adsorption and desorption capacities and the highest desorption ratio for the two glucuronides among the tested resins. Sorption isotherms were constructed for D141 resin under optimal ethanol conditions and fitted well to the Freundlich and Langmuir models (R2 > 0.95). Dynamic adsorption and desorption tests was performed on column packed with D141 resin. After one-run treatment with D141 resin, the two-constituent content in the final product was increased from 2.14% and 1.34% in the crude extract of Erigeron multiradiatus to 24.63% and 18.42% in the final products with the recoveries of 82.5% and 85.4%, respectively. The preparative separation of SG and AG can be easily and effectively achieved via adsorption and desorption on D141 resin, and the method developed can be referenced for large-scale separation and purification of flavone glucuronides from herbal raw materials
Tandem-pumped, tunable thulium-doped fiber laser in 21 μm wavelength region
We present a continuously tunable thulium(Tm)-doped fiber laser operating in the important 2.1 μm region, which is tandem-pumped by another Tm-doped fiber laser at 1908 nm. The advantages of pumping a Tm-doped fiber laser at the long-wavelength absorption tail (>1900 nm) of the fiber include a reduced quantum-defect, and efficient suppression of the amplified spontaneous noise (and potential parasitic lasing) at the short-wavelength region. This facilitates attainment of stable lasing operation in the long-wave emission tail of the Tm fiber at ~2.1 μm. By rotating a diffraction grating inside the Tm fiber laser cavity, we experimentally achieved a wavelength-tuning range of 2000-2172 nm. At central wavelengths of 2050 nm, 2150 nm, and 2172 nm, the slope efficiencies were 23%, 16%, and 9.9%, respectively. To the best of our knowledge, this is the first demonstration of long-wavelength operation of a Tm fiber laser system tandem-pumped at >1900 nm
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