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Symmetrization of quasi-regular patterns with periodic tilting of regular polygons

Computational Visual Media 2024年第3期10卷 559-576页

作者： Zhengzheng Yin Yao jin Zhijian Fang Yun zhang Huaxiong zhang Jiu Zhou Lili He School of Computer Science and Technology Zhejiang Sci-Tech UniversityHangzhou 310018China Zhejiang Provincial Innovation Center of Advanced Textile Technology Shaoxing 312000China School of Media engineering Communication University of ZhejiangHangzhou 310018China

Computer-generated aesthetic patterns arewidely used as design materials in various fields. Themost common methods use fractals or dynamicalsystems as basic tools to create various patterns. Toenhance aesthetics and controllability, some researchershave introduced symmetric layouts along with thesetools. One popular strategy employs dynamical systemscompatible with symmetries that construct functionswith the desired symmetries. However, these aretypically confined to simple planar symmetries. Theother generates symmetrical patterns under theconstraints of tilings. Although it is slightly moreﬂexible, it is restricted to small ranges of tilingsand lacks textural variations. Thus, we proposed anew approach for generating aesthetic patterns bysymmetrizing quasi-regular patterns using general kuniformtilings. We adopted a unified strategy toconstruct invariant mappings for k-uniform tilings thatcan eliminate texture seams across the tiling ***, we constructed three types of symmetriesassociated with the patterns: dihedral, rotational, andreﬂection symmetries. The proposed method can beeasily implemented using GPU shaders and is highlyefficient and suitable for complicated tiling with regularpolygons. experiments demonstrated the advantages of our method over state-of-the-art methods in terms ofﬂexibility in controlling the generation of patterns withvarious parameters as well as the diversity of texturesand styles.

关键词： quasi-regular patterns(QRP) k-uniform tilings invariant mappings symmetry aesthetic patterns

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SDCC: software-defined collective communication for distributed training

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Science China(Information Sciences) 2024年第9期67卷 105-125页

作者： Xin jin Zhen zhang Yunshan JIA Yun MA Xuanzhe LIU School of Computer Science Peking University Department of Computer Science and Technology Johns Hopkins University

Communication is crucial to the performance of distributed training. Today's solutions tightly couple the control and data planes and lack flexibility, generality, and performance. In this study, we present SDCC, a software-defined collective communication framework for distributed training. SDCC is based on the principle of modern systems design to effectively decouple the control plane from the data *** abstracts the operations for collective communication in distributed training with dataflow operations and unifies computing and communication with a single dataflow graph. The abstraction, together with the unification, is powerful: it enables users to easily express new and existing collective communication algorithms and optimizations, simplifies the integration with different computing engines(e.g., Py Torch and Tensor Flow) and network transports(e.g., Linux TCP and kernel bypass), and allows the system to improve performance by exploiting parallelism exposed by the dataflow graph. We further demonstrate the benefits of SDCC in four use cases.

关键词： machine learning systems distributed training deep learning collective communication software-defined networking

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extraction of eugenol from essential Oils by In Situ Formation of Deep eutectic Solvents:A Green Recyclable Process

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Journal of Analysis and Testing 2024年第1期8卷 63-73页

作者： Lingqi Shen Xiangzi jin Zhihui zhang Yuexing Yi jingyu zhang Zuguang Li College of Chemical engineering Zhejiang University of TechnologyHangzhou 310014China Department of Chemistry Yanbian UniversityYanji 133002China Transfar Zhilian Co. Ltd.Hangzhou 311215China

eugenol is extensively utilized in chemical *** actual production,it is mainly separated from clove essential oils(eOs)through acid-base *** this work,a simple,rapid and effective extraction process was developed for the extraction of eugenol from eOs samples by directly forming deep eutectic solvents(DeSs)without using acid-base *** proposed process is designed to dissolve eOs in n-hexane and eugenol was highly selective extracted into DeSs with tetrabutylammonium chloride(TBAC).Hydrogen bonds in DeSs can be broken by addition of water,resulting in a separation of the two phases,thus obtaining a hydrophobic yellowish eugenol in the upper *** quaternary ammonium salt in the lower aqueous solution can be reused after *** most determining influence factors such as the structure of quaternary ammonium salt,the mole ratio of quaternary ammonium salt to eugenol and the amount of n-hexane were *** forming conditions of DeSs were studied by Box-Behnken design(BBD).experiment was carried out under the optimal conditions and good experimental result was demonstrated by the developed process,a high extraction recovery of 92.51% and the purity was about 98.50%,which verifies the excellent performance for the proposed process.

关键词： eugenol Deep eutectic solvent essential oils Tetrabutylammonium chloride

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Insight into vertical piezoelectric characteristics regulated thermal transport in van der Waals two-dimensional materials

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Rare Metals 2024年第2期43卷 770-779页

作者： Dong-Hai Wei e Zhou jin-Yuan Xu Hui-Min Wang Chen Shen Hong-Bin zhang Zhen-Zhen Qin Guang-Zhao Qin State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha410082China Hunan Key Laboratory for Micro-Nano energy Materials and Device and School of Physics and Optoelectronics Xiangtan UniversityXiangtan411105China Institute of Materials Science Technical University of DarmstadtAlarich-Weiss-Str.264287DarmstadtGermany School of Physics and Microelectronics Zhengzhou UniversityZhengzhou450001China

The urgent demand of extreme(ultra-high/low)thermal conductivity materials is triggered by the high-power device,where exploring the theories and mechanisms of regulating thermal transport properties plays a key ***,we elaborately investigate the effect of vertical(out-of-plane)piezoelectric characteristics on thermal transport,which is historically *** different stacking-order(AA and AB)bilayer boron nitride(Bi-BN)in two-dimensional(2D)materials are selected as study *** performing state-of-the-art first-principles calculations,it is found that the polarization charge along the out-of-plane orientation ascends significantly with the increasing piezoelectric response in AB stacked Bi-BN(Bi-BN-AB)followed by the enhanced interlayer B–N atomic ***,the amplitude of phonon anharmonicity in Bi-BN-AB increases larger than that in the AA stacked Bi-BN(Bi-BN-AA),resulting in the dramatic weakening of the thermal conductivity by 20.34%under 18%*** research reveals the significant role of the vertical(out-of-plane)piezoelectric characteristic in regulating thermal transport and provides new insight into accurately exploring the thermal transport performance of 2D van der Waals materials.

关键词： Thermal conductivity Piezoelectric effect 2D materials Bilayer BN Strain engineering

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FSCIL-eACA: Few-Shot Class-Incremental Learning Network Based on embedding Augmentation and Classifier Adaptation for Image Classification

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Chinese Journal of electronics 2024年第1期33卷 139-152页

作者： Ruru zhang Haihong e Meina SONG School of Computer Science Beijing University of Posts and Telecommunications education Department Information Network engineering Research Center Beijing University of Posts and Telecommunications

The ability to learn incrementally is critical to the long-term operation of AI systems. Benefiting from the power of few-shot class-incremental learning(FSCIL), deep learning models can continuously recognize new classes with only a few samples. The difficulty is that limited instances of new classes will lead to overfitting and exacerbate the catastrophic forgetting of the old classes. Most previous works alleviate the above problems by imposing strong constraints on the model structure or parameters, but ignoring embedding network transferability and classifier adaptation(CA), failing to guarantee the efficient utilization of visual features and establishing relationships between old and new classes. In this paper, we propose a simple and novel approach from two perspectives: embedding bias and classifier bias. The method learns an embedding augmented(eA) network with cross-class transfer and class-specific discriminative abilities based on self-supervised learning and modulated attention to alleviate embedding bias. Based on the adaptive incremental classifier learning scheme to realize incremental learning capability,guiding the adaptive update of prototypes and feature embeddings to alleviate classifier bias. We conduct extensive experiments on two popular natural image datasets and two medical datasets. The experiments show that our method is significantly better than the baseline and achieves state-of-the-art results.

关键词： Training Adaptation models Visualization Image recognition Prototypes Self-supervised learning Power capacitors

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Multi-spheric interactions driven differential formation and accumulation of hydrocarbon resources in the North Sea Basin

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Science China earth Sciences 2024年第11期67卷 3397-3420页

作者： Rixiang ZHU Shuichang zhang Huajian WANG Xiaomei WANG Yuke LIU Wang zhang Fang HAO Zhijun jin Key Laboratory of Deep Petroleum Intelligent exploration and Development Institute of Geology and Geophysics Chinese Academy of Sciences State Key Laboratory of enhanced Oil & Gas Recovery Research Institute of Petroleum Exploration and Development China National Petroleum Corporation State Key Laboratory of Deep Oil and Gas China University of Petroleum (East China) Institute of energy Peking University

The North Sea Basin is the most important oil and gas producing area in europe and the birthplace of many classic petroleum geological theories. From the perspective of multi-spheric interactions in the earth, this study investigated the riftforeland-rift evolution process of the North Sea Basin, which was controlled by the deep dynamic driving forces of the continental collision orogeny, mantle plume uplift, and intraplate deformation. The North Sea Basin was found to have drifted northward since the Carboniferous and passed through the low-latitude Hadley and the mid-latitude Ferrel cells. Two sets of main hydrocarbon source rocks have formed, the coals and coal measures of the Upper Carboniferous Westphalian and the marine shale of the Upper Jurassic Kimmeridge Clay Formation. We propose that the deep processes, tectonic activity, and transgression-climate evolution jointly controlled the types and horizons of the source rocks, reservoirs, and seals in different regions of the North Sea Basin. In the southern North Sea Basin, a Carboniferous-Lower Triassic gas-rich petroleum system was formed,which is characterized by transitional coal measure source rocks, desert aeolian sandstone reservoirs, and evaporite cap rocks. In the northern North Sea Basin, an Upper Triassic-Paleogene oil-rich petroleum system was formed, which is characterized by marine graben-type source rocks, deltaic sandstone and marine limestone reservoirs, and marine tight marl and shale cap *** late tectonic burial and uplift in the North Sea Basin further controlled the processes of oil and gas generation and accumulation, ultimately leading to a differential distribution pattern which is oil rich in the northern part and gas rich in the southern part of the basin. In the future, there is an urgent need to re-examine the mechanisms for the petroleum generation and accumulation in large mature exploration areas(e.g., super basins such as the North Sea) and low exploration areas(e.g., the O

关键词： North Sea Basin Multi-spheric interactions Petroleum system Okhotsk Sea region

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event-triggered H_(∞) consensus control for input-constrained multi-agent systems via reinforcement learning

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Control Theory and Technology 2024年第1期22卷 25-38页

作者： jinxuan zhang Chang-e Ren College of Information engineering Capital Normal UniversityBeijing100089China

This article presents an event-triggered H_(∞) consensus control scheme using reinforcement learning (RL) for nonlinear second-order multi-agent systems (MASs) with control constraints. First, considering control constraints, the constrained H_(∞) consensus problem is transformed into a multi-player zero-sum game with non-quadratic performance functions. Then, an event-triggered control method is presented to conserve communication resources and a new triggering condition is developed for each agent to make the triggering threshold independent of the disturbance attenuation level. To derive the optimal controller that can minimize the cost function in the case of worst disturbance, a constrained Hamilton–Jacobi–Bellman (HJB) equation is defined. Since it is difficult to solve analytically due to its strongly non-linearity, reinforcement learning (RL) is implemented to obtain the optimal controller. In specific, the optimal performance function and the worst-case disturbance are approximated by a time-triggered critic network;meanwhile, the optimal controller is approximated by event-triggered actor network. After that, Lyapunov analysis is utilized to prove the uniformly ultimately bounded (UUB) stability of the system and that the network weight errors are UUB. Finally, a simulation example is utilized to demonstrate the effectiveness of the control strategy provided.

关键词： H_(∞)optimal control Input constrains Multi-agent systems(MASs) Reinforcement learning(RL)

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Nicotinamide adenine dinucleotide treatment confers resistance to neonatal ischemia and hypoxia:effects on neurobehavioral phenotypes

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Neural Regeneration Research 2024年第12期19卷 2760-2772页

作者： Xiaowen Xu Xinxin Wang Li zhang Yiming jin Lili Li Meifang jin Lianyong Li Hong Ni Division of Brain Science Institute of Pediatric ResearchChildren’s Hospital of Soochow UniversitySuzhouJiangsu ProvinceChina Department of Pediatric Orthopedics Shengjing Hospital of China Medical UniversityShenyangLiaoning ProvinceChina

Neonatal hypoxic-ischemic brain injury is the main cause of hypoxic-ischemic encephalopathy and cerebral ***,there are few effective clinical treatments for neonatal hypoxic-ischemic brain ***,we investigated the neuroprotective and molecular mechanisms of exogenous nicotinamide adenine dinucleotide,which can protect against hypoxic injury in adulthood,in a mouse model of neonatal hypoxic-ischemic brain *** this study,nicotinamide adenine dinucleotide(5 mg/kg)was intraperitoneally administered 30 minutes befo re surgery and every 24 hours *** results showed that nicotinamide adenine dinucleotide treatment improved body weight,brain structure,adenosine triphosphate levels,oxidative damage,neurobehavioral test outcomes,and seizure threshold in experimental *** mass tag proteomics revealed that numerous proteins were altered after nicotinamide adenine dinucleotide treatment in hypoxic-ischemic brain injury *** reaction monitoring and western blotting confirmed changes in the expression levels of proteins including serine(or cysteine)peptidase inhibitor,clade A,member 3N,fibronectin 1,5'-nucleotidase,cytosolic IA,microtubule associated protein 2,and complexin *** analyses showed that nicotinamide adenine dinucleotide ameliorated hypoxic-ischemic injury through inflammation-related signaling pathways(e.g.,nuclear factor-kappa B,mitogen-activated protein kinase,and phosphatidylinositol 3 kinase/protein kinase B).These findings suggest that nicotinamide adenine dinucleotide treatment can improve neurobehavioral phenotypes in hypoxic-ischemic brain injury mice through inflammation-related pathways.

关键词： brain injury cerebral palsy hypoxia hypoxic-ischemic brain injury inflammation neuroprotection nicotinamide adenine dinucleotide neonate nicotinamide adenine dinucleotide proteomics

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Close-packed layer spacing as a practical guideline for structure symmetry manipulation of IV-VI/I-V-VI_(2) thermoelectrics

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InfoMat 2024年第2期6卷 99-106页

作者： Tao jin Long Yang Xinyue.zhang Wen Li Yanzhong Pei Interdisciplinary Materials Research Center School of Materials Science and EngineeringTongji UniversityShanghaithe People's Republic of China

The crystal-structure symmetry in real space can be inherited in the reciprocal space,making high-symmetry materials the top candidates for thermoelectrics due to their potential for significant electronic band degeneracy.A practical indicator that can quantitatively describe structural changes would help facilitate the advanced thermoelectric material *** face-centered cubic structures,the spatial environment of the same crystallographic plane family is isotropic,such that the distances between the close-packed layers can be derived from the atomic distances within the *** by this,the relationship between inter-and intra-layer geometric information can be used to compare crystal structures with their desired cubic *** close-packed layer spacing was found to be a practical guideline of crystal structure symmetry in IV-VI chalcogenides and I-V-VI_(2) ternary semiconductors,both of which are historically important *** continuous structural evolution toward high symmetry can be described by the layer spacing when temperature or/and composition change,which is demonstrated by a series of pristine and alloyed thermoelectric materials in this *** layerspacing-based guideline provides a quantitative pathway for manipulating crystal structures to improve the electrical and thermal properties of thermoelectric materials.

关键词： phase transition structure manipulation thermoelectric materials x-ray diffraction

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Self-Triggered Set Stabilization of Boolean Control Networks and Its Applications

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Ieee/CAA Journal of Automatica Sinica 2024年第7期11卷 1631-1642页

作者： Rong Zhao Jun-e Feng Dawei zhang the School of Mathematics Shandong UniversityShandong UniversityJinan 250100China

Set stabilization is one of the essential problems in engineering systems, and self-triggered control(STC) can save the storage space for interactive information, and can be successfully applied in networked control systems with limited communication resources. In this study, the set stabilization problem and STC design of Boolean control networks are investigated via the semi-tensor product technique. On the one hand, the largest control invariant subset is calculated in terms of the strongly connected components of the state transition graph, by which a graph-theoretical condition for set stabilization is derived. On the other hand, a characteristic function is exploited to determine the triggering mechanism and feasible controls. Based on this, the minimum-time and minimum-triggering open-loop, state-feedback and output-feedback STCs for set stabilization are designed,respectively. As classic applications of self-triggered set stabilization, self-triggered synchronization, self-triggered output tracking and self-triggered output regulation are discussed as well. Additionally, several practical examples are given to illustrate the effectiveness of theoretical results.

关键词： Boolean control networks(BCNs) output regulation self-triggered control semi-tensor product of matrices set stabilization synchronization

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