242 research outputs found
Emergent Gravity from the Entanglement Structure in Group Field Theory
We couple a scalar field encoding the entanglement between manifold sites to
group field theory (GFT). The scalar field provides a relational clock that
enables the derivation of the Hamiltonian of the system from the GFT action.
Inspecting this Hamiltonian, we show that a theory of emergent gravity arises,
and that the theory is equivalent to the Ashtekar variables' formulation of
general relativity. The evolution of the system in GFT is a renormalization
group (RG) flow, which corresponds to a simplified Ricci flow, the generator of
which is the Hamiltonian, and the corresponding flow equation is regulated by
the Shroedinger equation. As a consequence of the quantization procedure, the
Hamiltonian is recovered to be non-Hermitian, and can be related to the complex
action formalism, in which the initial conditions and the related future
evolution of the systems are dictated by the imaginary part of the action.Comment: 15 page
Inductive Graph Transformer for Delivery Time Estimation
Providing accurate estimated time of package delivery on users' purchasing
pages for e-commerce platforms is of great importance to their purchasing
decisions and post-purchase experiences. Although this problem shares some
common issues with the conventional estimated time of arrival (ETA), it is more
challenging with the following aspects: 1) Inductive inference. Models are
required to predict ETA for orders with unseen retailers and addresses; 2)
High-order interaction of order semantic information. Apart from the
spatio-temporal features, the estimated time also varies greatly with other
factors, such as the packaging efficiency of retailers, as well as the
high-order interaction of these factors. In this paper, we propose an inductive
graph transformer (IGT) that leverages raw feature information and structural
graph data to estimate package delivery time. Different from previous graph
transformer architectures, IGT adopts a decoupled pipeline and trains
transformer as a regression function that can capture the multiplex information
from both raw feature and dense embeddings encoded by a graph neural network
(GNN). In addition, we further simplify the GNN structure by removing its
non-linear activation and the learnable linear transformation matrix. The
reduced parameter search space and linear information propagation in the
simplified GNN enable the IGT to be applied in large-scale industrial
scenarios. Experiments on real-world logistics datasets show that our proposed
model can significantly outperform the state-of-the-art methods on estimation
of delivery time. The source code is available at:
https://github.com/enoche/IGT-WSDM23.Comment: 9 pages, accepted to WSDM 202
Stimulus Intervals Modulate the Balance of Brain Activity in the Human Primary Somatosensory Cortex: An ERP Study
Neuronal excitation and inhibition occur in the brain at the same time, and brain activation reflects changes in the sum of excitation and inhibition. This principle has been well-established in lower-level sensory systems, including vision and touch, based on animal studies. However, it is unclear how the somatosensory system processes the balance between excitation and inhibition. In the present ERP study, we modified the traditional spatial attention paradigm by adding double stimuli presentations at short intervals (i.e., 10, 30, and 100 ms). Seventeen subjects participated in the experiment. Five types of stimulation were used in the experiment: a single stimulus (one raised pin for 40 ms), standard stimulus (eight pins for 40 ms), and double stimuli presented at intervals of 10, 30, and 100 ms. The subjects were asked to attend to a particular finger and detect whether the standard stimulus was presented to that finger. The results showed a clear attention-related ERP component in the single stimulus condition, but the suppression components associated with the three interval conditions seemed to be dominant in somatosensory areas. In particular, we found the strongest suppression effect in the ISI-30 condition (interval of 30 ms) and that the suppression and enhancement effects seemed to be counterbalanced in both the ISI-10 and ISI-100 conditions (intervals of 10 and 100 ms, respectively). This type of processing may allow humans to easily discriminate between multiple stimuli on the same body part
Using Left and Right Brains Together: Towards Vision and Language Planning
Large Language Models (LLMs) and Large Multi-modality Models (LMMs) have
demonstrated remarkable decision masking capabilities on a variety of tasks.
However, they inherently operate planning within the language space, lacking
the vision and spatial imagination ability. In contrast, humans utilize both
left and right hemispheres of the brain for language and visual planning during
the thinking process. Therefore, we introduce a novel vision-language planning
framework in this work to perform concurrent visual and language planning for
tasks with inputs of any form. Our framework incorporates visual planning to
capture intricate environmental details, while language planning enhances the
logical coherence of the overall system. We evaluate the effectiveness of our
framework across vision-language tasks, vision-only tasks, and language-only
tasks. The results demonstrate the superior performance of our approach,
indicating that the integration of visual and language planning yields better
contextually aware task execution.Comment: 19 pages, 13 figure
A New Method for Haptic Shape Discriminability Detection
Touch shape discrimination is not only closely related to tactile mechanoreceptors but also higher cognitive function. However, previous shape discrimination methods are difficult to complete in a short time, and the devices are complicated to operate and not user-friendly for nonprofessionals. Here, we propose a new method, the evaluation quantity of which is the angle discrimination threshold. In addition, to make this method easy to use for nonprofessionals, we designed a haptic angle sorting system, including the device and software. To evaluate this method, the angle sorting and two-angle discrimination experiments were compared, and it was found that participants spent significantly less time in the former experiment than in the latter. At the same time, there is a strong correlation between the performance of angle sorting and two-angle discrimination, which shows that the angle threshold obtained by the new method can also be used to evaluate the ability of touch discrimination. Moreover, the angle sorting results of different age groups also further demonstrate the feasibility of the method. The efficiency of this new method and the effectiveness of the system also provide a convenient means for evaluating haptic shape discrimination, which may have potential clinical application value in the early diagnosis of peripheral neuropathy and even in the evaluation of cognitive function
High-throughput discovery of chemical structure-polarity relationships combining automation and machine learning techniques
As an essential attribute of organic compounds, polarity has a profound
influence on many molecular properties such as solubility and phase transition
temperature. Thin layer chromatography (TLC) represents a commonly used
technique for polarity measurement. However, current TLC analysis presents
several problems, including the need for a large number of attempts to obtain
suitable conditions, as well as irreproducibility due to non-standardization.
Herein, we describe an automated experiment system for TLC analysis. This
system is designed to conduct TLC analysis automatically, facilitating
high-throughput experimentation by collecting large experimental data under
standardized conditions. Using these datasets, machine learning (ML) methods
are employed to construct surrogate models correlating organic compounds'
structures and their polarity using retardation factor (Rf). The trained ML
models are able to predict the Rf value curve of organic compounds with high
accuracy. Furthermore, the constitutive relationship between the compound and
its polarity can also be discovered through these modeling methods, and the
underlying mechanism is rationalized through adsorption theories. The trained
ML models not only reduce the need for empirical optimization currently
required for TLC analysis, but also provide general guidelines for the
selection of conditions, making TLC an easily accessible tool for the broad
scientific community
Elevated monocyte-to-HDL cholesterol ratio predicts post-stroke depression
ObjectivesInflammation plays an important role in the development of depression after stroke. Monocyte-to-HDL Cholesterol Ratio (MHR) recently emerged as a novel comprehensive inflammatory indicator in recent years. This study aimed to investigate whether there is a relationship between MHR levels and post-stroke depression (PSD).MethodsFrom February 2019 to September 2021, patients with acute ischemic stroke (AIS) were recruited within 7 days post-stroke from the two centers and blood samples were collected after admission. The 17-item Hamilton Depression Scale (HAMD-17) was used to measure depressive symptoms at 3 months after stroke. Patients were given the DSM-V criteria for diagnosis of PSD.ResultsOf the 411 enrolled patients, 92 (22.38%) patients were diagnosed with PSD at 3-months follow-up. The results also showed significantly higher level of MHR in patients with depression [0.81 (IQR 0.67–0.87) vs. 0.61 (IQR 0.44–0.82), P < 0.001] at admission than patients without depression. Multivariate logistic regression revealed that MHR (OR 6.568, 95% CI: 2.123–14.565, P = 0.015) was an independent risk factor for the depression at 3 months after stroke. After adjustment for potential confounding factors, the odds ratio of PSD was 5.018 (95% CI: 1.694–14.867, P = 0.004) for the highest tertile of MHR compared with the lowest tertile. Based on the ROC curve, the optimal cut-off value of MHR as an indicator for prediction of PSD was projected to be 0.55, which yielded a sensitivity of 87% and a specificity of 68.3%, with the area under the curve at 0.660 (95% CI: 0.683–0.781; P = 0.003).ConclusionElevated level of MHR was associated with PSD at 3 months, suggesting that MHR might be a useful Inflammatory markers to predict depression after stroke
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