Mitigating Transformer Overconfidence via Lipschitz Regularization

Though Transformers have achieved promising results in many computer vision tasks, they tend to be over-confident in predictions, as the standard Dot Product Self-Attention (DPSA) can barely preserve distance for the unbounded input domain. In this work, we fill this gap by proposing a novel Lipschitz Regularized Transformer (LRFormer). Specifically, we present a new similarity function with the distance within Banach Space to ensure the Lipschitzness and also regularize the term by a contractive Lipschitz Bound. The proposed method is analyzed with a theoretical guarantee, providing a rigorous basis for its effectiveness and reliability. Extensive experiments conducted on standard vision benchmarks demonstrate that our method outperforms the state-of-the-art single forward pass approaches in prediction, calibration, and uncertainty estimation.Comment: Accepted by UAI 2023. (https://proceedings.mlr.press/v216/ye23a.html

Foundation Reinforcement Learning: towards Embodied Generalist Agents with Foundation Prior Assistance

Recently, people have shown that large-scale pre-training from internet-scale data is the key to building generalist models, as witnessed in NLP. To build embodied generalist agents, we and many other researchers hypothesize that such foundation prior is also an indispensable component. However, it is unclear what is the proper concrete form to represent those embodied foundation priors and how they should be used in the downstream task. In this paper, we propose an intuitive and effective set of embodied priors that consist of foundation policy, value, and success reward. The proposed priors are based on the goal-conditioned MDP. To verify their effectiveness, we instantiate an actor-critic method assisted by the priors, called Foundation Actor-Critic (FAC). We name our framework as Foundation Reinforcement Learning (FRL), since it completely relies on embodied foundation priors to explore, learn and reinforce. The benefits of FRL are threefold. (1) Sample efficient. With foundation priors, FAC learns significantly faster than traditional RL. Our evaluation on the Meta-World has proved that FAC can achieve 100% success rates for 7/8 tasks under less than 200k frames, which outperforms the baseline method with careful manual-designed rewards under 1M frames. (2) Robust to noisy priors. Our method tolerates the unavoidable noise in embodied foundation models. We show that FAC works well even under heavy noise or quantization errors. (3) Minimal human intervention: FAC completely learns from the foundation priors, without the need of human-specified dense reward, or providing teleoperated demos. Thus, FAC can be easily scaled up. We believe our FRL framework could enable the future robot to autonomously explore and learn without human intervention in the physical world. In summary, our proposed FRL is a novel and powerful learning paradigm, towards achieving embodied generalist agents

Low-voltage-driven and highly-diffractive holographic polymer dispersed liquid crystals with spherical morphology

It is a constant pursuit to form highly-diffractive and low-voltage-driven holographic polymer dispersed liquid crystals (HPDLCs) for meeting the requirements of practical applications. Nevertheless, the high-voltage-driven characteristic is usually given while improving the diffraction efficiency of HPDLCs, and it remains a challenge to form HPDLCs with concurrent features of high diffraction and low driving voltage via a simple method. In this work, we synthesize a non-room-temperature LC, 4-butyloxy-4′-cyanobiphenyl (4OCB), and mix it with a room-temperature nematic LC mixture named P0616A. These new LC mixtures are then homogeneously mixed with monomers and a photoinitibitor composed of 3,3′-carbonylbis(7-diethylaminocoumarin) (KCD) and N-phenylglycine (NPG), followed by patterning via laser interference, generating well-structured HPDLCs. The introduction of 4OCB into the standard formulation is found to be able to optimize the morphology and electro-optical properties of the resulting HPDLC transmission gratings. By doping 5 wt% of 4OCB into the HPDLCs, a high diffraction efficiency of 92 ± 3% is obtained; meanwhile, the threshold and saturated voltages significantly decrease by 80.8% (i.e., from 12.0 ± 0.8 to 2.3 ± 0.9 V μm−1) and 73.2% (i.e., from 19.0 ± 0.6 to 5.1 ± 0.7 V μm−1), respectively, in comparison with the pristine. The enhanced performance is believed to be ascribed to the formed larger LC droplets (70 ± 20 nm) and lower interface anchoring strength (0.7 μN m−1) of the polymer network on LCs

Screening and evaluating of long noncoding RNAs in the puberty of goats

GO analysis of predicted targets of lncRNAs in trans. (XLS 1551 kb

Prevalence and genotype distribution of HPV infection among women in Xiamen, China

ObjectiveThis study aimed to evaluate the prevalence of HPV and genotype distribution among female populations in Xiamen, Fujian Province, China, which can be conducive for local governments to formulate cervical cancer screening and HPV vaccine strategies.MethodsCervical swabs were collected from 47,926 participants aged 16–92 years at the Women and Children’s Hospital, Xiamen University, from November 2019 to June 2020. HPV DNA was extracted and detected using conventional PCR, followed by HPV subtype-specific hybridisation. HPV infection rates based on different groups were compared using the χ2 test. HPV prevalence and the corresponding 95% confidence intervals (95% CI) were calculated using SPSS 19.0.ResultsThe overall HPV prevalence among the 47,926 cervical swabs that were analysed was 15.13%, of which single, double, and multiple infections accounted for 76.83, 16.70 and 6.47%, respectively. The age-specific prevalence of HPV infection presented a “U” curve with a HPV prevalence peak observed in women aged <20 years. The gynaecology clinic group had significantly higher HPV positive rates than the health examination group (p < 0.001). The five most common HR-HPV subtypes in Xiamen were HPV52, 58, 16, 51, and 39 (2.69, 1.63, 1.23, 1.05, and 0.98%, respectively). The five most common LR-HPV subtypes were HPV54, 61, 81, 70, 34, and 84 (0.92, 0.86, 0.71, 0.45 and 0.35%, respectively).ConclusionOur findings demonstrate that the 9-valent HPV vaccine is recommended for regular immunisation in Xiamen. It is necessary for elderly women to participate in HPV screening to decrease the morbidity and mortality of cervical cancer

Criteria for determining the need for surgical treatment of tricuspid regurgitation during mitral valve replacement

<p>Abstract</p> <p>Background</p> <p>Tricuspid regurgitation (TR) is common in patients with mitral valve disease; however, there are no straightforward, rapidly determinably criteria available for deciding whether TR repair should be performed during mitral valve replacement. The aim of our retrospective study was to identify a simple and fast criterion for determining whether TR repair should be performed in patients undergoing mitral valve replacement.</p> <p>Methods</p> <p>We reviewed the records of patients who underwent mitral valve replacement with or without (control) TR repair (DeVega or Kay procedure) from January 2005 to December 2008. Preoperative and 2-year postoperative echocardiographic measurements included right ventricular and atrial diameter, interventricular septum size, TR severity, ejection fraction, and pulmonary artery pressure.</p> <p>Results</p> <p>A total of 89 patients were included (control, n = 50; DeVega, n = 27; Kay, n = 12). Demographic and clinical characteristics were similar between groups. Cardiac variables were similar between the DeVega and Kay groups. Right atrium and ventricular diameter and ejection fraction were significantly decreased postoperatively both in the control and operation (DeVega + Kay) group (<it>P </it>< 0.05). Pulmonary artery pressure was significantly decreased postoperatively in-operation groups (<it>P </it>< 0.05). Our findings indicate that surgical intervention for TR should be considered during mitral valve replacement if any of the following preoperative criteria are met: right atrial transverse diameter > 57 mm; right ventricular end-diastolic diameter > 55 mm; pulmonary artery pressure > 58 mmHg.</p> <p>Conclusions</p> <p>Our findings suggest echocardiography may be used as a rapid and simple means of determining which patients require TR repair during mitral valve replacement.</p

Effect of MWNT Functionalization with Tunable-Length Block Copolymers on Dispersity of MWNTs and Mechanical Properties of Epoxy/MWNT Composites

The dispersion level of carbon nanotubes (CNTs) and interface design are two of the most crucial roles in developing the superior mechanical performance of polymer/CNT nanocomposites. In this work, a series of azide-terminated poly(glycidyl methacrylate)-block-poly(hexyl methacrylate) (PGMA-b-PHMA) copolymers with different PHMA chain lengths and similar PGMA chain lengths were grafted on the surface of multiwall carbon nanotubes (MWNTs). PHMA length changes significantly impact the grafting density and solubility in organic solvents of as-prepared block copolymer functionalized MWNTs(bc@fMWNTs). Then, the bc@fMWNTs were introduced to epoxy, and the resulted epoxy/bc@fMWNT composites show better mechanical properties than neat epoxy and epoxy/p-MWNT composites. The results suggest that longer PHMA chains cause the two competitive and opposing effects on the dispersion state and soft interface. On the one hand, the longer PHMA chains on the surface of MWNTs would afford higher deformation for the matrix and enhanced mobility for MWNTs because of the soft and flexible nature of PHMA, enhancing the energy dissipation during strain. On the other hand, as the length of PHMA extends, the dispersion level of bc@fMWNTs in epoxy declines, which is harmful to the composite&rsquo;s mechanical properties. Hence, epoxy/bc@fMWNTs composites with relatively short PHMA chains show the best tensile and fracture properties

Interference effects in the sum frequency generation spectra of thin organic films. II: Applications to different thin-film systems

In this paper, the results of the modeling calculations carried out for predicting the interference effects expected in the sum frequency generation (SFG) spectra of a specific thin-layer system, described in the accompanying paper, are tested by comparing them with the experimental spectra obtained for a real thin-layer film comprising an organic monolayer/variable thickness dielectric layer/gold substrate. In this system, two contributions to the SFG spectra arise, a resonant contribution from the organic film and a nonresonant contribution from the gold substrate. The modeling calculations are in excellent agreement with the experimental spectra over a wide range of thicknesses and for different polarization combinations. The introduction of another resonant monolayer adjacent to the gold substrate and with the molecules having a reverse orientation has a significant affect on the spectral shapes which is predicted. If a dielectric substrate such as CaF2 is used instead of a gold substrate, only the spectral intensities vary with the film thickness but not the spectral shapes. The counterpropagating beam geometry will change both the thickness dependent spectral shapes and the intensity of different vibrational modes in comparison with a copropagating geometry. The influences of these experimental factors, i.e., the molecular orientational structure in the thin film, the nature of the substrate, and the selected incident beam geometry, on the experimental SFG spectra are quantitatively predicted by the calculations. The thickness effects on the signals from a SFG active monolayer contained in a thin liquid-layer cell of the type frequently used for in situ electrochemical measurements is also discussed. The modeling calculation is also valid for application to other thin-film systems comprising more than two resonant SFG active interfaces by appropriate choice of optical geometries and relevant optical properties

A Mitigation Method for Optical-Turbulence-Induced Errors and Optimal Target Design in Vision-Based Displacement Measurement

Computer vision-based displacement measurement techniques are increasingly used for structural health monitoring. However, the vision sensors employed are easily affected by optical turbulence when capturing images of the structure, resulting in displacement measurement errors that significantly reduce the accuracy required in engineering applications. Hence, this paper develops a multi-measurement point method to address this problem by mitigating optical-turbulence errors with spatial randomness. Then, the effectiveness of the proposed method in mitigating optical-turbulence errors is verified by static target experiments, in which the RMSE correction rate can reach up to 82%. Meanwhile, the effects of target size and the number of measurement points on the proposed method are evaluated, and the optimal target design criteria are proposed to improve our method’s performance in mitigating optical-turbulence errors under different measurement conditions. Additionally, extensive dynamic target experiments reveal that the proposed method achieves an RMSE correction rate of 69% after mitigating the optical-turbulence error. The experimental results demonstrate that the proposed method improves the visual displacement measurement accuracy and retains the detailed information of the displacement measurement results