Modeling and a Domain Decomposition Method with Finite Element Discretization for Coupled Dual-Porosity Flow and Navier–Stokes Flow

In This Paper, We First Propose and Analyze a Steady State Dual-Porosity-Navier–Stokes Model, Which Describes Both Dual-Porosity Flow and Free Flow (Governed by Navier–Stokes Equation) Coupled through Four Interface Conditions, Including the Beavers–Joseph Interface Condition. Then We Propose a Domain Decomposition Method for Efficiently Solving Such a Large Complex System. Robin Boundary Conditions Are Used to Decouple the Dual-Porosity Equations from the Navier–Stokes Equations in the Coupled System. based on the Two Decoupled Sub-Problems, a Parallel Robin-Robin Domain Decomposition Method is Constructed and Then Discretized by Finite Elements. We Analyze the Convergence of the Domain Decomposition Method with the Finite Element Discretization and Investigate the Effect of Robin Parameters on the Convergence, Which Also Provide Instructions for How to Choose the Robin Parameters in Practice. Three Cases of Robin Parameters Are Studied, Including a Difficult Case Which Was Not Fully Addressed in the Literature, and the Optimal Geometric Convergence Rate is Obtained. Numerical Experiments Are Presented to Verify the Theoretical Conclusions, Illustrate How the Theory Can Provide Instructions on Choosing Robin Parameters, and Show the Features of the Proposed Model and Domain Decomposition Method

I-LLM: Efficient Integer-Only Inference for Fully-Quantized Low-Bit Large Language Models

Post-training quantization (PTQ) serves as a potent technique to accelerate the inference of large language models (LLMs). Nonetheless, existing works still necessitate a considerable number of floating-point (FP) operations during inference, including additional quantization and de-quantization, as well as non-linear operators such as RMSNorm and Softmax. This limitation hinders the deployment of LLMs on the edge and cloud devices. In this paper, we identify the primary obstacle to integer-only quantization for LLMs lies in the large fluctuation of activations across channels and tokens in both linear and non-linear operations. To address this issue, we propose I-LLM, a novel integer-only fully-quantized PTQ framework tailored for LLMs. Specifically, (1) we develop Fully-Smooth Block-Reconstruction (FSBR) to aggressively smooth inter-channel variations of all activations and weights. (2) to alleviate degradation caused by inter-token variations, we introduce a novel approach called Dynamic Integer-only MatMul (DI-MatMul). This method enables dynamic quantization in full-integer matrix multiplication by dynamically quantizing the input and outputs with integer-only operations. (3) we design DI-ClippedSoftmax, DI-Exp, and DI-Normalization, which utilize bit shift to execute non-linear operators efficiently while maintaining accuracy. The experiment shows that our I-LLM achieves comparable accuracy to the FP baseline and outperforms non-integer quantization methods. For example, I-LLM can operate at W4A4 with negligible loss of accuracy. To our knowledge, we are the first to bridge the gap between integer-only quantization and LLMs. We've published our code on anonymous.4open.science, aiming to contribute to the advancement of this field

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

Effects of double-root-cutting grafting on root growth, endogenous hormone content and nutrient uptake in watermelon seedlings

[Objective] Grafting has many advantages, such as increasing yield, improving nutrition and water uptake, and raising resistance to soil-borne diseases and damage caused by biotic or abiotic stressors. It has become a common practice in watermelon. Although the utilization of watermelon grafting has been steadily increasing over time and 95% of commercial watermelon productions actually rely on it in some regions of the world, the higher cost of grafted watermelon transplants is still one of the primary factors limiting application in regions with medium and large-scale production. The labor-efficient automation of grafting has been recognized as a key factor in the wider adoption of grafting. In growing cucurbits, the root-one-cotyledon-removing grafting method is the most commonly used with grafting machines. For root-cutting-one-cotyledon grafting method, root development is an important factor for seedling quality. Because acquiring strong roots is the main purpose for grafting, it is important to understand the root development of grafted seedlings. However, there is little information on the root growth of root-cutting grafted seedlings. In order to apply this grafting technology efficiently, the influence of root-cutting grafting on the root growth and mineral nutrient absorption of watermelon seedlings was studied. [Methods] The watermelon variety Zaojia 84-24 was used as the scion, and the pumpkin variety Zhenzhuang was used as the rootstock. The scion and rootstock seeds were respectively sown into 98-and 72-cell trays with one seed in one cellfilled with mixed seedling substrate (peat moss and pearlite at a volume ratio of 3∶1). The seeds of rootstock and scion were sown on the same day to meet the requirements for grafting experiments. The plants were cultivated in an artificial chamber with a day/night (12 h/12 h) cycle at 28 ℃/18 ℃ with 60%-80% relative humidity. Grafting was performed after the first true leaf developed on the rootstock and scion at 10th day after sowing. When grafting, the seedlings were divided into two groups. One group was grafted using root-cutting-one-cotyledon grafting method (DRC). After grafting, the plants were transplanted into 72-cell tray-plug with mixed seedling substrate. The other group was grafted using one-cotyledon splice grafting method (CK), in that rootstock had intact root system. The grafted seedlings were placed under a plastic film with a day/night cycle at 28 ℃/18 ℃ with more than 90% humidity under low light intensity (75 μmol·m-2·s-1, 12 h/12 h photoperiod) for healing. The grafted plants were exposed to the air 1-3 h per day until the scions were alive and grew. After the healing process, the root growth parameters such as root morphology indexes, root activity and scattered lump rate were measured at 6-day interval. At the same time, samples were also harvested for examining the hormone and mineral contents. [Results] The root diameter of grafted watermelon seedlings with pumpkin root-cutting was thick while the root length, root surface area, root volume, root tip number, root fresh weight and root dry weight were significantly reduced. The scattering lump rate of grafted watermelon seedlings with pumpkin root-cutting was 86.7% while the scattering rate of grafted watermelon seedlings with the control was only 13.3% on the 12th day after grafting. The contents of IAA, CTK and ETH in the root of grafted watermelon seedlings with pumpkin root-cutting significantly increased while the contents of GA and ABA significantly decreased. The contents of N, P, K, Mg, Fe and B in stems and roots of grafted watermelon seedlings with pumpkin root-cutting showing a certain degree of increase. However, the contents of Ca in stems and roots of grafted watermelon seedlings with pumpkin root-cutting decreased significantly. [Conclusion] A well-developed root system induced vigorous stem growth and plant development, and root growth was also influenced by stem. The root of watermelon seedlings grafted by root-cutting grafting method was regenerated with adventitious roots. The regenerated root system had higher root activity and mineral absorption capacity. The contents of N, P, K, Fe, Mg and B increased in grafted watermelon seedlings with pumpkin root-cutting. At the same time, the seedlings increased the IAA, CTK and ETH contents of root to promote the root growth. However, the seedlings by using this grafting method had not enough root system at the early stage, which decreased the accumulation of mineral elements. The content of Ca was reduced in grafted watermelon seedlings with pumpkin root-cutting, which may be related to the difference in root architecture, but further research is needed to understand the decrease of Ca absorption. The results of this study can provide theoretical guidance for the fertilizer management of watermelon grafting seedlings, and promote the popularization and application of mechanized grafting technology

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

ATLAS Run 1 searches for direct pair production of third-generation squarks at the Large Hadron Collider

This paper reviews and extends searches for the direct pair production of the scalar supersymmetric partners of the top and bottom quarks in proton-proton collisions collected by the ATLAS collaboration during the LHC Run 1. Most of the analyses use 20 fb$^{-1}$ of collisions at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV, although in some case an additional 4.7 fb$^{-1}$ of collision data at $\sqrt{s}$ = 7 TeV are used. New analyses are introduced to improve the sensitivity to specific regions of the model parameter space. Since no evidence of third-generation squarks is found, exclusion limits are derived by combining several analyses and are presented in both a simplified model framework, assuming simple decay chains, as well as within the context of more elaborate phenomenological supersymmetric models