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有向图上基于层次树索引的最大cycle truss社区搜索
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作者 宗传玉 张纯鹤 夏秀峰 《计算机应用》 CSCD 2024年第1期190-198,共9页
社区搜索旨在从信息网络中找出包含用户查询顶点的高内聚连通子图,cycle truss是一种基于cycle三角形的社区搜索模型,而现有的基于索引的cycle truss社区搜索方法存在索引空间大、搜索效率低、社区内聚性低的缺点。为了解决这一问题,提... 社区搜索旨在从信息网络中找出包含用户查询顶点的高内聚连通子图,cycle truss是一种基于cycle三角形的社区搜索模型,而现有的基于索引的cycle truss社区搜索方法存在索引空间大、搜索效率低、社区内聚性低的缺点。为了解决这一问题,提出一种基于层次树索引的最大cycle truss社区搜索方法。首先,提出了k-cycle truss分解算法,并引入了两个重要的概念:cycle三角连通与k-层次等价。基于k-层次等价设计了层次树索引TreeCIndex与表结构索引SuperTable,在此基础上,并基于这两个新的索引,提出了两个高效的cycle truss社区搜索算法。在4个真实数据集上与已有的基于TrussIndex与EquiTruss的社区搜索算法进行了比较,实验结果表明,TreeCIndex与SuperTable比TrussIndex与EquiTruss节省至少41.5%的空间,索引构建的时间节省8.2%至98.3%,且搜索最大cycle truss社区的效率分别高出了一个和两个数量级。 展开更多
关键词 有向图 社区搜索 cycle truss cycle三角形 层次等价 层次树索引
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Jovian Planet Influence on the Forcing of Sunspot Cycles
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作者 Fred J. Cadieu 《World Journal of Condensed Matter Physics》 CAS 2024年第1期1-9,共9页
The history of our solar system has been greatly influenced by the fact that there is a large gas giant planet, Jupiter that has a nearly circular orbit. This has allowed relics of the early solar system formation to ... The history of our solar system has been greatly influenced by the fact that there is a large gas giant planet, Jupiter that has a nearly circular orbit. This has allowed relics of the early solar system formation to still be observable today. Since Jupiter orbits the Sun with a period of approximately 12 years, it has always been thought that this could be connected to the nearly 11-year periodic peak in the number of sunspots observed. In this paper, the Sun and planets are considered to be moving about a center of mass point as the different planets orbit the Sun. This is the action of gravity that holds the solar system together. The center of mass for the Jupiter-Sun system actually lies outside the Sun. The four gas giant planets dominate such effects and the four gas giant Jovian planets can be projected together to determine an effective distance from the Sun’s center. Taken together these effects do seem to function as a sunspot forcing factor with a periodicity very close to 11 years. These predictions are made without consideration of any details of what is happening in the interior of the Sun. From these estimates, sunspot cycle 25 will be expected to peak in about September-October of 2025. Sunspot cycle 26 should peak in the year March of 2037. 展开更多
关键词 Sun cycles Solar System Formation JUPITER
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Hydrangea serrata extract exerts tumor inhibitory activity against hepatocellular carcinoma HepG2 cells via inducing p27/CDK2-mediated cell cycle arrest and apoptosis
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作者 Ye-eun Kim Jeonghye Hwang Ki-Young Kim 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2024年第2期65-72,I0002-I0005,共12页
Objective:To examine the inhibitory effect of Hydrangea serrata extract against hepatocellular carcinoma HepG2 cells and its underlying mechanisms.Methods:The effects of Hydrangea serrata extract on growth inhibition ... Objective:To examine the inhibitory effect of Hydrangea serrata extract against hepatocellular carcinoma HepG2 cells and its underlying mechanisms.Methods:The effects of Hydrangea serrata extract on growth inhibition of tumor cells and spheroids were assessed using MTT and 3D culture assays.Quantitative real-time PCR and Western blot analyses were employed to investigate the changes in mRNA and protein expression levels of molecules related to cell cycle and apoptosis.Results:Hydrangea serrata extract effectively inhibited the growth of both tumor cells and spheroids.The extract also significantly upregulated p27 mRNA expression and downregulated CDK2 mRNA expression,leading to cell cycle arrest.Moreover,increased BAX/Bcl-2 ratio as well as caspase-9 and-3 were observed after treatment with Hydrangea serrata extract,indicating the induction of tumor cell apoptosis.Conclusions:Hydrangea serrata extract has the potential to alleviate tumors by effectively modulating cell-cycle-related gene expressions and inducing apoptosis,thereby inhibiting tumor growth. 展开更多
关键词 Hydrangea serrata Hepatocellular carcinoma Liver cancer Anticancer Cell cycle arrest APOPTOSIS
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Dual‑Atom Nanozyme Eye Drops Attenuate Inflammation and Break the Vicious Cycle in Dry Eye Disease
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作者 Dandan Chu Mengyang Zhao +8 位作者 Shisong Rong Wonho Jhe Xiaolu Cai Yi Xiao Wei Zhang Xingchen Geng Zhanrong Li Xingcai Zhang Jingguo Li 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第6期439-457,共19页
Dry eye disease(DED)is a major ocular pathology worldwide,causing serious ocular discomfort and even visual impairment.The incidence of DED is gradually increasing with the highfrequency use of electronic products.Alt... Dry eye disease(DED)is a major ocular pathology worldwide,causing serious ocular discomfort and even visual impairment.The incidence of DED is gradually increasing with the highfrequency use of electronic products.Although inflammation is core cause of the DED vicious cycle,reactive oxygen species(ROS)play a pivotal role in the vicious cycle by regulating inflammation from upstream.Therefore,current therapies merely targeting inflammation show the failure of DED treatment.Here,a novel dual-atom nanozymes(DAN)-based eye drops are developed.The antioxidative DAN is successfully prepared by embedding Fe and Mn bimetallic single-atoms in N-doped carbon material and modifying it with a hydrophilic polymer.The in vitro and in vivo results demonstrate the DAN is endowed with superior biological activity in scavenging excessive ROS,inhibiting NLRP3 inflammasome activation,decreasing proinflammatory cytokines expression,and suppressing cell apoptosis.Consequently,the DAN effectively alleviate ocular inflammation,promote corneal epithelial repair,recover goblet cell density and tear secretion,thus breaking the DED vicious cycle.Our findings open an avenue to make the DAN as an intervention form to DED and ROSmediated inflammatory diseases. 展开更多
关键词 Dry eye disease DAN Dual-atom nanozyme Vicious cycle NLRP3 inflammasome NANOMEDICINE
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Effect of drying-wetting cycles on pore characteristics and mechanical properties of enzyme-induced carbonate precipitation-reinforced sea sand
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作者 Ming Huang Kai Xu +2 位作者 Zijian Liu Chaoshui Xu Mingjuan Cui 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期291-302,共12页
Enzyme-induced carbonate precipitation(EICP)is an emanating,eco-friendly and potentially sound technique that has presented promise in various geotechnical applications.However,the durability and microscopic character... Enzyme-induced carbonate precipitation(EICP)is an emanating,eco-friendly and potentially sound technique that has presented promise in various geotechnical applications.However,the durability and microscopic characteristics of EICP-treated specimens against the impact of drying-wetting(D-W)cycles is under-explored yet.This study investigates the evolution of mechanical behavior and pore charac-teristics of EICP-treated sea sand subjected to D-W cycles.The uniaxial compressive strength(UCS)tests,synchrotron radiation micro-computed tomography(micro-CT),and three-dimensional(3D)recon-struction of CT images were performed to study the multiscale evolution characteristics of EICP-reinforced sea sand under the effect of D-W cycles.The potential correlations between microstructure characteristics and macro-mechanical property deterioration were investigated using gray relational analysis(GRA).Results showed that the UCS of EICP-treated specimens decreases by 63.7% after 15 D-W cycles.The proportion of mesopores gradually decreases whereas the proportion of macropores in-creases due to the exfoliated calcium carbonate with increasing number of D-W cycles.The micro-structure in EICP-reinforced sea sand was gradually disintegrated,resulting in increasing pore size and development of pore shape from ellipsoidal to columnar and branched.The gray relational degree suggested that the weight loss rate and UCS deterioration were attributed to the development of branched pores with a size of 100-1000 m m under the action of D-W cycles.Overall,the results in this study provide a useful guidancee for the long-term stability and evolution characteristics of EICP-reinforced sea sand under D-W weathering conditions. 展开更多
关键词 Enzyme-induced carbonate precipitation(EICP) Plant-based urease Drying-wetting(D-W)cycles Microstructure
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Summer Atmospheric Water Cycle under the Transition Influence of the Westerly and Summer Monsoon over the Yarlung Zangbo River Basin in the Southern Tibetan Plateau
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作者 Qianhui MA Chunyan ZHANG +1 位作者 Donghai WANG Zihao PANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第5期830-846,共17页
This study compares the summer atmospheric water cycle,including moisture sources and consumption,in the upstream,midstream,and downstream regions of the Yarlung Zangbo River Basin in the southern Tibetan Plateau.The ... This study compares the summer atmospheric water cycle,including moisture sources and consumption,in the upstream,midstream,and downstream regions of the Yarlung Zangbo River Basin in the southern Tibetan Plateau.The evolutions of moisture properties under the influence of the westerly and summer southerly monsoon are examined using 5-yr multi-source measurements and ERA5 reanalysis data.Note that moisture consumption in this study is associated with clouds,precipitation,and diabatic heating.Compared to the midstream and downstream regions,the upstream region has less moisture,clouds,and precipitation,where the moisture is brought by the westerly.In early August,the vertical wet advection over this region becomes enhanced and generates more high clouds and precipitation.The midstream region has moisture carried by the westerly in June and by the southerly monsoon from July to August.The higher vertical wet advection maximum here forms more high clouds,with a precipitation peak in early July.The downstream region is mainly affected by the southerly-driven wet advection.The rich moisture and strong vertical wet advection here produce the most clouds and precipitation among the three regions,with a precipitation peak in late June.The height of the maximum moisture condensation is different between the midstream region(325 hPa)and the other two regions(375 hPa),due to the higher upward motion maximum in the midstream region.The diabatic heating structures show that stratiform clouds dominate the upstream region,stratiform clouds and deep convection co-exist in the midstream region,and deep convection systems characterize the downstream region. 展开更多
关键词 Yarlung Zangbo River Basin atmospheric water cycle constrained variational analysis moisture source and consumption
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Involvement of the ABA-and H_(2)O_(2)-Mediated Ascorbate-Glutathione Cycle in the Drought Stress Responses of Wheat Roots
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作者 Mengyuan Li Zhongye Gao +2 位作者 Lina Jiang Leishan Chen Jianhui Ma 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第2期329-342,共14页
Abscisic acid(ABA),hydrogen peroxide(H_(2)O_(2)) and ascorbate(AsA)–glutathione(GSH)cycle are widely known for their participation in various stresses.However,the relationship between ABA and H_(2)O_(2) levels and th... Abscisic acid(ABA),hydrogen peroxide(H_(2)O_(2)) and ascorbate(AsA)–glutathione(GSH)cycle are widely known for their participation in various stresses.However,the relationship between ABA and H_(2)O_(2) levels and the AsA–GSH cycle under drought stress in wheat has not been studied.In this study,a hydroponic experiment was conducted in wheat seedlings subjected to 15%polyethylene glycol(PEG)6000–induced dehydration.Drought stress caused the rapid accumulation of endogenous ABA and H_(2)O_(2) and significantly decreased the number of root tips compared with the control.The application of ABA significantly increased the number of root tips,whereas the application of H_(2)O_(2) markedly reduced the number of root tips,compared with that under 15%PEG-6000.In addition,drought stress markedly increased the DHA,GSH and GSSG levels,but decreased the AsA levels,AsA/DHA and GSH/GSSG ratios compared with those in the control.The activities of the four enzymes in the AsA–GSH cycle were also markedly increased under drought stress,including glutathione reductase(GR),ascorbate peroxidase(APX),monodehydroascorbate reductase(MDHAR)and dehydroascorbate reductase(DHAR),compared with those in the control.However,the application of an ABA inhibitor significantly inhibited GR,DHAR and APX activities,whereas the application of an H_(2)O_(2) inhibitor significantly inhibited DHAR and MDHAR activities.Furthermore,the application of ABA inhibitor significantly promoted the increases of H_(2)O_(2) and the application of H_(2)O_(2) inhibitor significantly blocked the increases of ABA,compared with those under 15% PEG-6000.Taken together,the results indicated that ABA and H_(2)O_(2) probably interact under drought stress in wheat;and both of them can mediate drought stress by modulating the enzymes in AsA–GSH cycle,where ABA acts as the main regulator of GR,DHAR,and APX activities,and H_(2)O_(2) acts as the main regulator of DHAR and MDHAR activities. 展开更多
关键词 ABA H_(2)O_(2) AsA-GSH cycle drought stress wheat roots
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Research into Applicability of Wöhler Curve Method for Low-Cycle Fatigue of Metallic Materials
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作者 Xiangqiao Yan 《Journal of Harbin Institute of Technology(New Series)》 CAS 2024年第2期22-37,共16页
Recently,a description on a practicability of the Wöhler Curve Method for low-cycle fatigue of metals was given by the author.By the description and the low cycle fatigue test data of 16 MnR steel,it is important... Recently,a description on a practicability of the Wöhler Curve Method for low-cycle fatigue of metals was given by the author.By the description and the low cycle fatigue test data of 16 MnR steel,it is important to show that,for low cycle fatigue of metals,such a way that a stress-based intensity parameter calculated by the linear-elastic analysis is taken to be a stress intensity parameter,S,to establish a relationship between the stress intensity parameter,S,and the fatigue life,N,is practicable.In this paper,many metallic materials from the literature are given to show that the Wöhler Curve Method is well suitable for low-cycle fatigue analysis of metals. 展开更多
关键词 low cycle fatigue Wöhler curve method coffin-manson curve method METALS
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Heteroclinic Cycles in a Class of 3-Dimensional Piecewise Affine Systems
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作者 Minghao Liu Ruimin Liu 《Journal of Applied Mathematics and Physics》 2024年第2期488-508,共21页
This paper explores the existence of heteroclinic cycles and corresponding chaotic dynamics in a class of 3-dimensional two-zone piecewise affine systems. Moreover, the heteroclinic cycles connect two saddle foci and ... This paper explores the existence of heteroclinic cycles and corresponding chaotic dynamics in a class of 3-dimensional two-zone piecewise affine systems. Moreover, the heteroclinic cycles connect two saddle foci and intersect the switching manifold at two points and the switching manifold is composed of two perpendicular planes. 展开更多
关键词 Piecewise Affine System Heteroclinic cycle Chaotic Invariant Set
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Application of PDCA Cycle in Hand Hygiene Management of Psychiatric Medical Staff
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作者 Li Xiang Weidong Liu +1 位作者 Guiying Chen Mei Liu 《Journal of Clinical and Nursing Research》 2024年第3期152-157,共6页
Objective:To study the application effect of the plan-do-check-act(PDCA)cycle management in the hand hygiene management of psychiatric medical staff.Methods:One hundred and twenty medical staff from a psychiatric hosp... Objective:To study the application effect of the plan-do-check-act(PDCA)cycle management in the hand hygiene management of psychiatric medical staff.Methods:One hundred and twenty medical staff from a psychiatric hospital from May 2023 to December 2023 were selected and divided into two groups.The control group(May 2023 to August 2023)applied the conventional management model,and the observation group(September 2023 to December 2023)applied the PDCA cycle management.The hand hygiene compliance,hand hygiene knowledge,and hygiene qualifications were compared,including the amount of hand sanitizer used.Results:The proportion of medical staff’s hand hygiene compliance and hand hygiene knowledge mastery scores in the observation group were higher than those in the control group(P<0.05);the hand hygiene passing rate in the observation group was higher than that of the control group(P<0.05);the daily amount of hand sanitizer per patient bed and the amount of hand sanitizer used was higher than that of the control group(P<0.05).Conclusion:The PDCA cycle management model for psychiatric medical staff promoted the improvement of hand hygiene compliance and increased their hand hygiene qualifications.It is suitable for further popularization and application in future clinical practice. 展开更多
关键词 PSYCHIATRY PDCA cycle management Hand hygiene management COMPLIANCE
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Conjuncture Cycles and Monetary Anomalies Are Unwelcome Guests for Sustainability
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作者 Giovanni Antonio Cossiga 《Economics World》 2024年第1期1-16,共16页
Economic cycles are not economic evils but rather healing agents for returning to equilibrium,just as inflation and deflation are not economic misfortunes but the sign of bad governance and a bitter medicine for retur... Economic cycles are not economic evils but rather healing agents for returning to equilibrium,just as inflation and deflation are not economic misfortunes but the sign of bad governance and a bitter medicine for returning to calm monetary.Unfortunately,signs of poor governance are mistaken for unfortunate events,but are instead tools offered to restore economic systems.Politics seeks consensus and does not accept the bitter cure of recession.Monetary policy is therefore called into question even if monetary anomalies also depend on errors in the management of the economy;the result is the gradual increase in interest rates.Is the idea that we can achieve the goal of complete neutrality with nature acceptable in a global economic framework pervaded by inflation and denunciation?Can we similarly argue that economic problems can coexist once the goal of neutrality has been achieved?The answer is negative.We must correct these anomalies and dysfunctions of the economy,which cannot coexist in the new context of complete and indefinite equilibrium of tomorrow.And not even the idea that conflicts can be resolved with war seems to find a place in the renewed scenario of neutrality.In this regard we can remember that,when we have reached the economic optimum of complete neutrality,or at least we are close to it,the most socially and economically advanced territories and continents will benefit from an acceleration of productivity and development.Scarcity itself will give way to the new,long-awaited reality.A condition that approaches the state of abundance and which will produce surpluses to be allocated to countries and territories that are struggling towards the condition of neutrality.The acceleration of lagging continents and the recovery of altered economic systems are therefore preconditions that can allow us to access the state of global neutrality.As we get closer to the great objective,it is to be believed that the pretense of regulating conflicts through war will also disappear.With the new reality of abundance,the economic reason for war disappears,while the aspiration of peoples-inscribed in their DNA-for solidarity and peaceful aggregation towards substantial unity becomes clear. 展开更多
关键词 monetary policy conjunctural cycles economic sustainability neutrality as goal continental aggregation
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基于CSLS-CycleGAN的侧扫声纳水下目标图像样本扩增法
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作者 汤寓麟 王黎明 +3 位作者 余德荧 李厚朴 刘敏 张卫东 《系统工程与电子技术》 EI CSCD 2024年第5期1514-1524,共11页
针对侧扫声纳水下目标图像稀缺,获取难度大、成本高,导致基于深度学习的目标检测模型性能差的问题,结合光学域类目标数据集丰富的现状,提出一种基于通道和空间注意力(channel and spatial attention,CSA)模块、最小二乘生成对抗生成网络... 针对侧扫声纳水下目标图像稀缺,获取难度大、成本高,导致基于深度学习的目标检测模型性能差的问题,结合光学域类目标数据集丰富的现状,提出一种基于通道和空间注意力(channel and spatial attention,CSA)模块、最小二乘生成对抗生成网络(least squares generative adversarial networks,LSGAN)及循环对抗生成网络(cycle generative adversarial networks,CycleGAN)的侧扫声纳水下目标图像样本扩增方法。首先,受CycleGAN的启发,设计基于循环一致性的单循环网络结构,保证模型的训练效率。然后,在生成器中融合CSA模块,减少信息弥散的同时增强跨纬度交互。最后,设计了基于LSGAN的损失函数,提高生成图像质量的同时提高训练稳定性。在船舶光学域数据集与侧扫声纳沉船数据集上进行实验,所提方法实现了光学-侧扫声纳样本间信息的高效、稳健转换以及大量侧扫声纳目标样本的扩增。同时,基于本文生成样本训练后的检测模型进行了水下目标检测,结果表明,使用本文样本扩增数据训练后的模型在少样本沉船目标检测的平均准确率达到了84.71%,证明了所提方法实现了零样本和小样本水下强代表性目标样本的高质量扩增,并为高性能水下目标检测模型构建提供了一种新的途径。 展开更多
关键词 样本扩增 侧扫声纳 循环生成对抗网络 通道和空间注意力模块 最小二乘生成对抗网络
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Ascending phase of solar cycle 25 tilts the current El Nino-Southern oscillation transition
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作者 Wenjuan Huo Ziniu Xiao +1 位作者 Liang Zhao Fei Liu 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第1期34-38,共5页
自2020年初夏,赤道太平洋地区出现拉尼娜现象并持续两年半多(以下简称2020拉尼娜),对其未来演变的预测引起了很多关注,考虑到11年太阳周期活动对热带太平洋SST异常可能存在锁相影响,本研究分析了当前太阳活动周(即第25太阳周(SC25))对... 自2020年初夏,赤道太平洋地区出现拉尼娜现象并持续两年半多(以下简称2020拉尼娜),对其未来演变的预测引起了很多关注,考虑到11年太阳周期活动对热带太平洋SST异常可能存在锁相影响,本研究分析了当前太阳活动周(即第25太阳周(SC25))对目前热带太平洋ENSO现象未来演变的调节作用,基于历史太阳周的统计特征,作者对第25太阳周达到其最大值的时间提出三种可能的情景,并讨论了不同情景下的太阳活动对未来两年ENSO演变的可能影响,第25太阳周的持续上升阶段在一定程度上抑制了当前2023厄尔尼诺现象发展为超级事件. 展开更多
关键词 厄尔尼诺-南方涛动 太阳活动 热带太平洋 位相转变 预测 三重拉尼娜现象
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基于改进CycleGAN的水下图像颜色校正与增强 被引量:5
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作者 李庆忠 白文秀 牛炯 《自动化学报》 EI CAS CSCD 北大核心 2023年第4期820-829,共10页
针对水下观测图像的颜色失真和散射模糊问题,提出一种基于改进循环一致性生成对抗网络(Cycle-consistent generative adversarial networks,CycleGAN)的水下图像颜色校正与增强算法.为了利用CycleGAN学习水下降质图像到空气中图像的映... 针对水下观测图像的颜色失真和散射模糊问题,提出一种基于改进循环一致性生成对抗网络(Cycle-consistent generative adversarial networks,CycleGAN)的水下图像颜色校正与增强算法.为了利用CycleGAN学习水下降质图像到空气中图像的映射关系,对传统CycleGAN的损失函数进行了改进,提出了基于图像强边缘结构相似度(Strong edge and structure similarity,SESS)损失函数的SESS-CycleGAN,SESS-CycleGAN可以在保留原水下图像的边缘结构信息的前提下实现水下降质图像的颜色校正和对比度增强.为了确保增强后图像和真实脱水图像颜色的一致性,建立了SESSCycleGAN和正向生成网络G相结合的网络结构;并提出了两阶段学习策略,即先利用非成对训练集以弱监督方式进行SESS-CycleGAN学习,然后再利用少量成对训练集以强监督方式进行正向生成网络G的监督式学习.实验结果表明:本文算法在校正水下图像颜色失真的同时还增强了图像对比度,且较好地实现了增强后图像和真实脱水图像视觉颜色的一致性. 展开更多
关键词 水下图像 深度学习 循环一致性生成对抗网络 颜色校正 图像增强
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基于CycleGAN图像增强的输送皮带洒料检测技术
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作者 吴淑娟 张铭 《吉林大学学报(信息科学版)》 CAS 2023年第6期1072-1078,共7页
为解决摄像头监拍煤矿输送皮带上矿料分布情况时,存在的光照条件不稳定、扬尘等干扰因素,从而导致直接对摄像头画面应用二值化获得矿料分布效果不稳定,容易出现漏检的问题,提出了一种基于Cycle GAN(Cycle Generative Adversarial Networ... 为解决摄像头监拍煤矿输送皮带上矿料分布情况时,存在的光照条件不稳定、扬尘等干扰因素,从而导致直接对摄像头画面应用二值化获得矿料分布效果不稳定,容易出现漏检的问题,提出了一种基于Cycle GAN(Cycle Generative Adversarial Networks)图像增强的输送皮带洒料检测技术。首先利用摄像头采集的煤矿输送皮带图像作为输入,经过Cycle GAN进行图像增强;然后采取二值化方法进行图像分割,准确获取输送皮带洒料的目标区域;最后采用阈值法和形态学处理对输送皮带洒料区域进行判断和检测。实验结果表明,该技术能有效地监测输送皮带上的洒料情况,并且在传统监测方法的基础上可提高监测准确率。 展开更多
关键词 循环生成对抗网络 图像增强 输送皮带 检测
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CMT Cycle Step工艺参数对焊缝表面特征纹路及成形尺寸的影响
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作者 周春东 章晓勇 +3 位作者 彭勇 王克鸿 王剑春 周明 《焊接学报》 EI CAS CSCD 北大核心 2023年第5期95-101,I0008,I0009,共9页
采用CMT Cycle Step焊接工艺进行平板堆焊正交试验,研究了送丝速度、焊接速度、熔滴数量和间隔时间四个参数对焊缝表面特征纹路及成形尺寸的影响,建立了各参数与焊缝表面鱼鳞纹步长S、焊缝熔宽B、堆焊层厚度h之间的回归模型.结果表明,... 采用CMT Cycle Step焊接工艺进行平板堆焊正交试验,研究了送丝速度、焊接速度、熔滴数量和间隔时间四个参数对焊缝表面特征纹路及成形尺寸的影响,建立了各参数与焊缝表面鱼鳞纹步长S、焊缝熔宽B、堆焊层厚度h之间的回归模型.结果表明,随着焊接速度、熔滴数量和间隔时间的增大,焊缝表面鱼鳞纹步长S呈逐渐增大的趋势.适当减小焊接速度和间隔时间,可有效减小焊缝表面高度差Δh,提高焊缝表面成形质量.随着送丝速度和熔滴数量的增大,焊缝熔宽B和堆焊层厚度h均逐渐增大;随着焊接速度的增大,焊缝熔宽B和堆焊层厚度h逐渐减小.根据理论分析和回归分析得到准确性较高的回归方程,为预测焊接焊缝成形以及优化焊接工艺参数提供理论依据.创新点:(1)系统研究了CMT Cycle Step焊接工艺参数对焊缝成形的影响规律,有助于采用该方法解决点焊、热敏感材料焊接、电弧增材制造等领域的相关技术难题.(2)建立了CMT Cycle Step焊接工艺的送丝速度、焊接速度、熔滴数量和间隔时间四个参数对焊缝表面特征纹路及成形尺寸回归模型,为预测焊缝成形以及优化焊接工艺参数提供理论依据.(3)对CMT Cycle Step焊缝表面特征纹路—鱼鳞纹进行量化评价,探究工艺参数对焊缝表面鱼鳞纹步长S和表面高度差Δh的影响规律,有利于获得高表面平整度的焊缝. 展开更多
关键词 CMT cycle Step 焊缝表面特征纹路 正交试验 焊缝成形
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基于CycleGAN的虚拟定量差分相衬成像用于红细胞分类
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作者 汪涛 彭韬 +5 位作者 蒋梦朵 张粲 张凯旋 陆凤雅 钟振声 周金华 《中国医疗设备》 2023年第4期1-6,12,共7页
目的通过深度学习技术实现虚拟定量差分相衬(Virtual Quantitative Differential Phase Contrast,V-qDPC)重建,提高定量相位成像衬度和鲁棒性,为无标记红细胞的全自动分类提供新思路。方法通过对LED照明进行编码获得明场图像和差分相衬... 目的通过深度学习技术实现虚拟定量差分相衬(Virtual Quantitative Differential Phase Contrast,V-qDPC)重建,提高定量相位成像衬度和鲁棒性,为无标记红细胞的全自动分类提供新思路。方法通过对LED照明进行编码获得明场图像和差分相衬图像,通过相位重建可获得定量差分相衬(Quantitative Differential Phase Contrast,qDPC)图像;采用循环一致生成对抗网络(Cycle-consistent Generative Adversarial Network,CycleGAN)完成明场图像到qDPC图像的端到端映射。结果基于CycleGAN生成的V-qDPC图像,实验参数当λ=7和β=0.5时,V-qDPC图像质量最优;相比光学重建的qDPC图像有更好的鲁棒性和抗噪声能力;使用AlexNet、ResNet50和VggNet三种网络模型比较无标记红细胞形态的自动分类,结果表明V-qDPC图像比qDPC图像具有更好分类性能。结论与传统的基于多幅倾斜照明图像的qDPC重建相比,V-qDPC算法具有更好的相位图像质量和鲁棒性,适合以高精度和高效率实现全自动细胞分类,同时省去了成像光路和硬件支持,有望应用于生物医学研究。 展开更多
关键词 定量差分相衬成像 无标记红细胞 循环一致生成对抗网络 全自动分类
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Solar cycle variations in equatorial ionospheric zonal electric fields near sunrise 被引量:1
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作者 JunJie Chen WenBin Wang +1 位作者 JiuHou Lei Tong Dang 《Earth and Planetary Physics》 EI CSCD 2023年第3期378-388,共11页
In this study,we investigate the solar cycle dependence of the sunrise ionospheric zonal electric fields at the equator under geomagnetically quiet conditions.Simulations using the Thermosphere–Ionosphere–Electrodyn... In this study,we investigate the solar cycle dependence of the sunrise ionospheric zonal electric fields at the equator under geomagnetically quiet conditions.Simulations using the Thermosphere–Ionosphere–Electrodynamics General Circulation Model(TIEGCM)reveal that the equatorial eastward electric field at sunrise decreases with the increase in solar activity,independent of longitude,season,and lower atmospheric tides.The solar cycle dependence of the sunrise zonal electric field is mainly related to the zonal wind dynamo.Moreover,this solar cycle dependence of sunrise electric fields at the equator is dominated by the corresponding variation in the F-region dynamo because the response of conductivity and neutral winds near sunrise to increasing solar flux is stronger in the F-region than in the E-region,although the sunrise eastward enhancement of electric fields is mainly driven by the E-region zonal wind dynamo.Specifically,the westward gradient of low-latitude F-region neutral winds near the dawn terminator tends to produce westward electric fields in the equatorial region that are more pronounced at solar maximum,whereas the midlatitude E-region dynamo induces an eastward enhancement of sunrise electric fields at the equator that decreases slightly with increasing solar activity.This study also reveals that the reason the eastward enhancement of equatorial zonal electric fields near dawn and dusk terminators show opposite solar cycle dependence is because of their different generation mechanisms. 展开更多
关键词 IONOSPHERE ELECTRODYNAMICS sunrise enhancement solar cycle dependence
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Integrated strategies for chemotherapy cycles in nasopharyngeal carcinoma patients: Real-world data from two epidemic centers guiding decision-making 被引量:1
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作者 Zejiang Zhan Yingying Huang +11 位作者 Jiayu Zhou Zhuochen Cai Haoyang Huang Ying Deng Wenze Qiu Xun Cao Xi Chen Chixiong Liang Lulu Zhang Xiang Guo Taize Yuan Xing Lyu 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2023年第2期126-139,共14页
objective:Two cycles of induction chemotherapy(IC)followed by 2 cycles of platinum-based concurrent chemoradiotherapy(CCRT)(2IC+2CCRT)for locoregionally advanced nasopharyngeal carcinoma(LA-NPC)is widely adopted but n... objective:Two cycles of induction chemotherapy(IC)followed by 2 cycles of platinum-based concurrent chemoradiotherapy(CCRT)(2IC+2CCRT)for locoregionally advanced nasopharyngeal carcinoma(LA-NPC)is widely adopted but not evidence-confirmed.This study aimed to determine the clinical value of 2IC+2CCRT regarding efficacy,toxicity and cost-effectiveness.Methods:This real-world study from two epidemic centers used propensity score matching(PSM)and inverse probability of treatment weighting(IPTW)analyses.The enrolled patients were divided into three groups based on treatment modality:Group A(2IC+2CCRT),Group B(3IC+2CCRT or 2IC+3CCRT)and Group C(3IC+3CCRT).Long-term survival,acute toxicities and cost-effectiveness were compared among the groups.We developed a prognostic model dividing the population into high-and low-risk cohorts,and survivals including overall survival(OS),progression-free survival(PFS),distant metastasis-free survival(DMFS)and locoregional relapse-free survival(LRRFS)were compared among the three groups according to certain risk stratifications.Results:Of 4,042 patients,1,175 were enrolled,with 660,419,and 96 included in Groups A,B and C,respectively.Five-year survivals were similar among the three groups after PSM and confirmed by IPTW.Grade 3-4 neutropenia and leukocytopenia were significantly higher in Groups C and B than in Group A(52.1%vs.41.5%vs.25.2%;41.7%vs.32.7%vs.25.0%)as were grade 3-4 nausea/vomiting and oral mucositis(29.2%vs.15.0%vs.6.1%;32.3%vs.25.3%vs.18.0%).Cost-effective analysis suggested that 2IC+2CCRT was the least expensive,while the health benefits were similar to those of the other groups.Further exploration showed that 2IC+2CCRT tended to be associated with a shorter PFS in high-risk patients,while 3IC+3CCRT potentially contributed to poor PFS in low-risk individuals,mainly reflected by LRRFS.Conclusions:In LA-NPC patients,2IC+2CCRT was the optimal choice regarding efficacy,toxicity and costeffectiveness;however,2IC+2CCRT and 3IC+3CCRT probably shortened LRRFS in high-and low-risk populations,respectively. 展开更多
关键词 Nasopharyngeal carcinoma treatment modality chemotherapy cycle survival toxicity COSTEFFECTIVENESS real world
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Effect of High Temperature Curing on the Frost Resistance of Recycled Aggregate Concrete and the Physical Properties of Second-Generation Recycled Coarse Aggregate under Freeze-Thaw Cycles 被引量:1
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作者 Xintong Chen Pinghua Zhu +2 位作者 Xiancui Yan Lei Yang Huayu Wang 《Journal of Renewable Materials》 SCIE EI 2023年第6期2953-2967,共15页
With the emphasis on environmental issues,the recycling of waste concrete,even recycled concrete,has become a hot spot in the field of architecture.But the repeated recycling of waste concrete used in harsh environmen... With the emphasis on environmental issues,the recycling of waste concrete,even recycled concrete,has become a hot spot in the field of architecture.But the repeated recycling of waste concrete used in harsh environments is still a complex problem.This paper discusses the durability and recyclability of recycled aggregate concrete(RAC)as a prefabricated material in the harsh environment,the effect of high-temperature curing(60℃,80℃,and 100℃)on the frost resistance of RAC and physical properties of the second generation recycled coarse aggregate(RCA_(2))of RAC after 300 freeze-thaw cycles were studied.The frost resistance of RAC was characterized by compressive strength,relative dynamic elastic modulus,and mass loss.As the physical properties of RCA_(2),the apparent density,water absorption,and crushing value were measured.And the SEM images of RAC after 300 freeze-thaw cycles were shown.The results indicated that the frost resistance of RAC cured at 80℃ for 7 days was comparable to that cured in the standard condition(cured for 28 days at 20℃±2℃ and 95%humidity),and the RAC cured at 100℃ was slightly worse.However,the frost resistance of RAC cured at 60℃ deteriorated seriously.The RAC cured at 80℃ for 7 days is the best.Whether after the freeze-thaw cycle or not,the RCA that curd at 60℃,80℃,and 100℃ for 7 days can also meet the requirements of Grade III RCA and be used as the aggregate of non-bearing part of prefabricated concrete components.RCA_(2) which is cured at 80℃ for 7 days had the best physical properties. 展开更多
关键词 Freeze-thaw cycles curing condition recycled aggregate concrete second-generation recycled coarse aggregate
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