174 research outputs found
Target before Shooting: Accurate Anomaly Detection and Localization under One Millisecond via Cascade Patch Retrieval
In this work, by re-examining the "matching" nature of Anomaly Detection
(AD), we propose a new AD framework that simultaneously enjoys new records of
AD accuracy and dramatically high running speed. In this framework, the anomaly
detection problem is solved via a cascade patch retrieval procedure that
retrieves the nearest neighbors for each test image patch in a coarse-to-fine
fashion. Given a test sample, the top-K most similar training images are first
selected based on a robust histogram matching process. Secondly, the nearest
neighbor of each test patch is retrieved over the similar geometrical locations
on those "global nearest neighbors", by using a carefully trained local metric.
Finally, the anomaly score of each test image patch is calculated based on the
distance to its "local nearest neighbor" and the "non-background" probability.
The proposed method is termed "Cascade Patch Retrieval" (CPR) in this work.
Different from the conventional patch-matching-based AD algorithms, CPR selects
proper "targets" (reference images and locations) before "shooting"
(patch-matching). On the well-acknowledged MVTec AD, BTAD and MVTec-3D AD
datasets, the proposed algorithm consistently outperforms all the comparing
SOTA methods by remarkable margins, measured by various AD metrics.
Furthermore, CPR is extremely efficient. It runs at the speed of 113 FPS with
the standard setting while its simplified version only requires less than 1 ms
to process an image at the cost of a trivial accuracy drop. The code of CPR is
available at https://github.com/flyinghu123/CPR.Comment: 13 pages,8 figure
Photonic Floquet time crystals
The public and scientists constantly have different perspectives. While on a
time crystal, they stand in line and ask: What is a time crystal? Show me a
material that is spontaneously crystalline in time? This study synthesizes a
photonic material of Floquet time crystals and experimentally observes its
indicative period-2T beating. We explicitly reconstruct a discrete
time-crystalline ground state and reveal using an appropriately-designed
photonic Floquet simulator the rigid period-doubling as a signature of the
spontaneous breakage of the discrete time-translational symmetry. Unlike the
result of the exquisite many-body interaction, the photonic time crystal is
derived from a single-particle topological phase that can be extensively
accessed by many pertinent nonequilibrium and periodically-driven platforms.
Our observation will drive theoretical and technological interests toward
condensed matter physics and topological photonics, and demystify time crystals
for the non-scientific public.Comment: 39 pages, 5 figures, supplementary materials, 6 suppl. figure
LBS: Loss-aware Bit Sharing for Automatic Model Compression
Low-bitwidth model compression is an effective method to reduce the model
size and computational overhead. Existing compression methods rely on some
compression configurations (such as pruning rates, and/or bitwidths), which are
often determined manually and not optimal. Some attempts have been made to
search them automatically, but the optimization process is often very
expensive. To alleviate this, we devise a simple yet effective method named
Loss-aware Bit Sharing (LBS) to automatically search for optimal model
compression configurations. To this end, we propose a novel single-path model
to encode all candidate compression configurations, where a high bitwidth
quantized value can be decomposed into the sum of the lowest bitwidth quantized
value and a series of re-assignment offsets. We then introduce learnable binary
gates to encode the choice of bitwidth, including filter-wise 0-bit for filter
pruning. By jointly training the binary gates in conjunction with network
parameters, the compression configurations of each layer can be automatically
determined. Extensive experiments on both CIFAR-100 and ImageNet show that LBS
is able to significantly reduce computational cost while preserving promising
performance.Comment: 22 page
The effect of cooling rate on the wear performance of a ZrCuAlAg bulk metallic glass
In the present work, the local atomic ordering and the wear performance of ZrCuAlAg bulk metallic glass (BMG) samples with different diameters have been studied using transmission electron microscopy (TEM) plus autocorrelation function analysis, and pin-on-disc dry sliding wear experiments. Differential scanning calorimetry and TEM studies show that smaller diameter BMG sample has higher free volume and less local atomic ordering. The wear experiments demonstrate that with the same chemical composition, the smaller BMG sample exhibits higher coefficient of friction, higher wear rate, and rougher worn surface than those of the larger ones. Compared with larger BMG sample, the faster cooling rate of the smaller sample results in looser atomic configuration with more free volume, which facilitates the formation of the shear bands, and thus leads to larger plasticity and lower wear resistance. The results provide more quantitative understanding on the relationship among the cooling rate, the local atomic ordering, and the wear performance of BMGs
Incidence of patients with bone metastases at diagnosis of solid tumors in adults: a large population-based study
Background: Bones are one of the most common metastatic sites for solid malignancies. Bone metastases can significantly increase mortality and decrease the quality of life of cancer patients. In the United States, around 350,000 people die each year from bone metastases. This study aimed to analyze and update the incidence and prognosis of bone metastases with solid tumors at the time of cancer diagnosis and its incidence rate for each solid cancer.Methods: We used the Surveillance, Epidemiology, and End Results (SEER) database to find patients diagnosed with solid cancers originating from outside the bones and joints between 2010 and 2016. Data were stratified by age, sex, and race. Patients with a tumor in situ or with an unknown bone metastases stage were excluded. We then selected most of the sites where cancer often occurred, leaving 2,207,796 patients for the final incidence analysis. For the survival analysis, patients were excluded if they were diagnosed at their autopsy or on their death certificate, or had unknown follow-ups. The incidence of bone metastases and overall survival was compared between patients with different primary tumor sites.Results: We identified 2,470,634 patients, including 426,594 patients with metastatic disease and 113,317 patients with bone metastases, for incidence analysis. The incidence of bone metastases among the metastatic subset was 88.74% in prostate cancer, 53.71% in breast cancer, and 38.65% in renal cancer. In descending order of incidence, there were patients with other cancers in the genitourinary system (except for renal, bladder, prostate, and testicular cancer) (37.91%), adenocarcinoma of the lung (ADC) (36.86%), other gynecologic cancers (36.02%), small- cell lung cancer (SCLC) (34.56%), non-small cell lung cancer not otherwise specified and others [NSCLC (NOS/others)] (33.55%), and bladder (31.08%) cancers. The rate of bone metastases is 23.19% in SCLC, 22.50% in NSCLC (NOS/others), 20.28% in ADC, 8.44% in squamous cell carcinoma of the lung (SCC), and 4.11% in bronchioloalveolar carcinoma [NSCLC (BAC)]. As for the digestive system, the overall bone metastases rate was 7.99% in the esophagus, 4.47% in the gastric cancer, 4.42% in the hepatobiliary cancer, 3.80% in the pancreas, 3.26% in other digestive organs, 1.24% in the colorectum, and 1.00% in the anus. Overall, the incidence rate of bone metastases among the entire cohort in breast and prostate cancer was 3.73% and 5.69%, respectively.Conclusions: The results of this study provide population-based estimates for the incidence rates of patients with bone metastases at initial diagnosis of their solid tumor. The findings can help clinicians to early detect bone metastases by bone screening to anticipate the occurrence of symptoms and favorably improve the prognosis
Topological Magnetoresistance of Magnetic Skyrmionic Bubbles
Magnetic skyrmions offer promising prospects for constructing future
energy-efficient and high-density information technology, leading to extensive
explorations of new skyrmionic materials recently. The topological Hall effect
has been widely adopted as a distinctive marker of skyrmion emergence.
Alternately, here we propose a novel signature of skyrmion state by
quantitatively investigating the magnetoresistance (MR) induced by skyrmionic
bubbles in CeMn2Ge2. An intriguing finding was revealed: the anomalous MR
measured at different temperatures can be normalized into a single curve,
regardless of sample thickness. This behavior can be accurately reproduced by
the recent chiral spin textures MR model. Further analysis of the MR anomaly
allowed us to quantitatively examine the effective magnetic fields of various
scattering channels. Remarkably, the analyses, combined with the Lorentz
transmission electronic microscopy results, indicate that the in-plane
scattering channel with triplet exchange interactions predominantly governs the
magnetotransport in the Bloch-type skyrmionic bubble state. Our results not
only provide insights into the quantum correction on MR induced by skyrmionic
bubble phase, but also present an electrical probing method for studying chiral
spin texture formation, evolution and their topological properties, which opens
up exciting possibilities for identifying new skyrmionic materials and
advancing the methodology for studying chiral spin textures.Comment: 17 pages,5 figures,submitte
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