1,104 research outputs found

    NUMERICAL ANALYSIS OF THE EFFECT OF SURCHARGE ON THE MECHANICAL BEHAVIOR OF GEOCELL REINFORCED RETAINING WALL

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    Geocell reinforced retaining structure has been widely used in civil engineering for theprotection of slopes due to its advantages. In this paper, the effects of surcharge on the horizontaldisplacement of the wall back, the size of the sliding wedge and the factor of safety of geocellreinforced retaining wall are numerically analyzed by employing the geotechnical finite elementmethod software Plaxis. The research results show that, when the distance of surcharge from thewall face is small, the maximum and the minimum deformation of the wall back takes place nearthe top of the wall and the wall bottom respectively. After the distance of surcharge from the wallface exceeds about 13% of the wall height, the surcharge has little effect on the horizontaldeformation of the wall back, the size of the sliding wedge and the safety factor of geocellreinforced retaining wall. The horizontal deformation of the wall back gradually increases with theincrease of the length of the surcharge until it reaches a certain value. The effect of the length ofthe surcharge on the failure surface is not significant. Besides, the factor of safety of the wallgradually decreases with the increase of length of the surcharge. However, with the increase of thedistance of the surcharge from the wall face, the influence of the length of the surcharge on thesafety factor gradually becomes small. The study results can supplement theoretical basis for thedesign of geocell reinforced retaining walls in engineering practices

    Probe nuclear structure using the anisotropic flow at the Large Hadron Collider

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    Recent studies have shown that the shape and radial profile of the colliding nuclei have strong influences on the initial condition of the heavy ion collisions and the subsequent development of the anisotropic flow. Using A Multi-Phase Transport model (AMPT) model, we investigated the impact of nuclear quadrupole deformation β2\beta_2 and nuclear diffuseness a0a_0 of 129^{129}Xe on various of flow observables in Xe--Xe collisions at \sqrtnn = 5.44 TeV. We found that β2\beta_2 has a strong influence on central collisions while a0a_0 mostly influences the mid-central collisions. The relative change of flow observables induced by a change in β2\beta_2 and a0a_0 are also found to be insensitive to the values of parameters controlling the strength of the interaction among final state particles. Our study demonstrates the potential for constraining the initial condition of heavy ion collisions using future system scans at the LHC.Comment: 25 pages, for the EPJA Topical Issue

    Retrieving non-linear features from noisy quantum states

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    Accurately estimating high-order moments of quantum states is an elementary precondition for many crucial tasks in quantum computing, such as entanglement spectroscopy, entropy estimation, spectrum estimation and predicting non-linear features from quantum states. But in reality, inevitable quantum noise prevents us from accessing the desired value. In this paper, we address this issue by systematically analyzing the feasibility and efficiency of extracting high-order moments from noisy states. We first show that there exists a quantum protocol capable of accomplishing this task if and only if the underlying noise channel is invertible. We then establish a method for deriving protocols that attain optimal sample complexity using quantum operations and classical post-processing only. Our protocols, in contrast to conventional ones, incur lower overheads and avoid sampling different quantum operations due to a novel technique called observable shift, making the protocols strong candidates for practical usage on current quantum devices. The proposed method also indicates the power of entangled protocols in retrieving high-order information, whereas in the existing methods, entanglement does not help. Our work contributes to a deeper understanding of how quantum noise could affect high-order information extraction and provides guidance on how to tackle it.Comment: 23 pages, 6 figure

    CatVersion: Concatenating Embeddings for Diffusion-Based Text-to-Image Personalization

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    We propose CatVersion, an inversion-based method that learns the personalized concept through a handful of examples. Subsequently, users can utilize text prompts to generate images that embody the personalized concept, thereby achieving text-to-image personalization. In contrast to existing approaches that emphasize word embedding learning or parameter fine-tuning for the diffusion model, which potentially causes concept dilution or overfitting, our method concatenates embeddings on the feature-dense space of the text encoder in the diffusion model to learn the gap between the personalized concept and its base class, aiming to maximize the preservation of prior knowledge in diffusion models while restoring the personalized concepts. To this end, we first dissect the text encoder's integration in the image generation process to identify the feature-dense space of the encoder. Afterward, we concatenate embeddings on the Keys and Values in this space to learn the gap between the personalized concept and its base class. In this way, the concatenated embeddings ultimately manifest as a residual on the original attention output. To more accurately and unbiasedly quantify the results of personalized image generation, we improve the CLIP image alignment score based on masks. Qualitatively and quantitatively, CatVersion helps to restore personalization concepts more faithfully and enables more robust editing.Comment: For the project page, please visit https://royzhao926.github.io/CatVersion-page

    Jet charge identification in ee-Z-qq process at Z pole operation

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    Accurate jet charge identification is essential for precise electroweak and flavor measurements at the high-energy frontier. We propose a novel method called the Leading Particle Jet Charge method (LPJC) to determine the jet charge based on information about the leading charged particle. Tested on Z - bb and Z - cc samples at a center-of-mass energy of 91.2GeV, the LPJC achieves an effective tagging power of 20%/9% for the c/b jet, respectively. Combined with the Weighted Jet Charge method (WJC), we develop a Heavy Flavor Jet Charge method (HFJC), which achieves an effective tagging power of 39%/20% for c/b jet, respectively. This paper also discusses the dependencies between jet charge identification performance and the fragmentation process of heavy flavor jets, and critical detector performances

    Lateglacial and Holocene climate change in the NE Tibetan Plateau : Reconciling divergent proxies of Asian summer monsoon variability

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    The nature of Holocene Asian summer monsoon (ASM) evolution documented by diverse natural archives remains controversial, with a contentious issue being whether or not a strong Asian summer monsoon prevailed during the early Holocene. Here we present sequences of multiple proxies measured in sediment cores from Genggahai Lake in the NE Tibetan Plateau (NETP). The results suggest that a higher lake level and relatively lower terrestrial vegetation cover occurred synchronously during the early Holocene (11.3–8.6 kyr cal BP), compared with the period from 8.6 to 6.9 kyr cal BP. This finding clearly reflects the existence of different hydroclimatic conditions between the lake and its catchment due to diverse driving mechanisms. The early Holocene high stand of the lake, as demonstrated by the stratigraphic variability of the remains of aquatic biota, may have responded to the strengthened ASM and increased monsoonal precipitation; the relatively low vegetation cover in the marginal region of the Asian monsoon during the early Holocene, and the coeval widespread active sand dune mobility in both the NE Tibetan Plateau and NE China, most likely resulted from a low level of effective moisture due to high evaporation, and hence they cannot be interpreted as evidence of a weak ASM. Our results potentially reconcile the current divergent interpretations of various proxy climate records from the region. Our findings suggest that the ASM evolution was characterized by a consistent pattern across the monsoonal regions, as indicated by the oxygen isotope record of Chinese speleothems.Peer reviewe

    Integration of Self-Adaptive Physical-Layer Key Distribution and Encryption in Optical Coherent Communication

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    We propose and experimentally demonstrate a compatible physical-layer secure optical communication (PLSOC) system that integrates self-adaptive physical-layer key distribution (PLKD) and encryption (PLE) in optical coherent communication. Based on bit error rate difference of QAM signals mapped by asymmetric basis state Y-00 protocol, the secret key can be secretly exchanged over public fiber links without the pre-shared keys. Moreover, we perform a parameter self-adaptive strategy for practical and dynamic PLKD. The security of the key is evaluated in the case of a fiber-tapping attack. A secure hash algorithm, SHA3-512, is used to perform privacy amplification to obtain the virtually secure key. An error-free PLKD rate reaches 39.3 Kbits/s over 300km ultra-low loss fiber. We experimentally enable the integration of the proposed PLKD scheme and quantum noise stream cipher (QNSC) with a single wavelength, same system. Q factor penalty of the integration system compared to the QNSC system is 3.7dB (optical back-to-back) and 4.8dB (300km) respectively. By exploiting a common hardware platform, with the same wavelength, the proposed PLSOC system addresses the problem that PLKD and PLE are separately performed through independent optical fiber links or wavelengths. Since only digital signal processing is used, the scheme does not require extra hardware
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