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Thermal-hydraulic performance analysis and multi-objective optimization of a microchannel with staggered semi-elliptical ribs

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Science China(Technological Sciences) 2024年第10期67卷 3152-3167页

作者： CUI pan LIU wei LIU ZhiChun School of Energy and Power Engineering Huazhong University of Science and TechnologyWuhan 430074China

To enhance the cooling capacity of traditional microchannels for high heat flux electronic devices,a microchannel design with staggered semi-elliptical ribs is proposed in this *** numerical simulations,the flow characteristics of the designed microchannel are compared with those of a smooth one,and the effects of rib width(W_(r)),rib height(H_(r)),and rib length(L_(r)),on the thermal-hydraulic performance are investigated under laminar flow *** results show that the periodically arranged ribs induce periodic vortices within the microchannel,effectively promoting fluid mixing and enhancing heat transfer.W_(r) and H_(r) have similar effects on microchannel performance,with an increase in them leading to an enhanced thermal performance at the expense of deteriorated hydraulic ***,L_(r) has a comparatively weaker influence,with both the heat transfer and flow resistance initially growing with increasing L_(r) and then *** strike a balance between the two performances,a multi-objective optimization on the three geometrical parameters is conducted at a Reynolds number(Re)of *** with simulation data,artificial neural networks are trained as surrogate models,and a multi-objective genetic algorithm is employed to derive the Pareto *** the TOPSIS decision-making method,an optimal compromise solution is determined as W_(r)=0.2415 mm,H_(r)=0.0976 mm,and L_(r)=0.6486 *** testing on the optimized microchannel reveals that it exhibits high heat transfer,middle flow resistance,and excellent overall performance,with the performance evaluation criterion(PEC)falling between 1.572 and 1.723 within the Re range of 220–660.

关键词： heat transfer enhancement microchannel semi-elliptical rib numerical simulation multi-objective optimization

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Sparse Signal Recovery via Exponential Metric Approximation

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Tsinghua Science and Technology 2017年第1期22卷 104-111页

作者： Jian pan Jun Tang wei Zhu Department of Electronic Engineering Tsinghua University Beijing 100084China

Sparse signal recovery problems are common in parameter estimation, image processing, pattern recognition, and so on. The problem of recovering a sparse signal representation from a signal dictionary might be classified as a linear constraint l_0-quasinorm minimization problem, which is thought to be a Non-deterministic Polynomial-time（NP）-hard problem. Although several approximation methods have been developed to solve this problem via convex relaxation, researchers find the nonconvex methods to be more efficient in solving sparse recovery problems than convex methods. In this paper a nonconvex Exponential Metric Approximation（EMA）method is proposed to solve the sparse signal recovery problem. Our proposed EMA method aims to minimize a nonconvex negative exponential metric function to attain the sparse approximation and, with proper transformation,solve the problem via Difference Convex（DC） programming. Numerical simulations show that exponential metric function approximation yields better sparse recovery performance than other methods, and our proposed EMA-DC method is an efficient way to recover the sparse signals that are buried in noise.

关键词： sparse recovery exponential metric approximation sparsity tolerance DC optimization signal-to-noiseratio

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Dynamics of a prey-predator system under Poisson white noise excitation

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Acta Mechanica Sinica 2014年第5期30卷 739-745页

作者： Shan-Shan pan wei-Qiu Zhu Department of Mechanics State Key Lab of Fluid Power Transmission and ControlZhejiang University

The classical Lotka-Volterra （LV） model is a well-known mathematical model for prey-predator ecosystems. In the present paper, the pulse-type version of stochastic LV model, in which the effect of a random natural environment has been modeled as Poisson white noise, is in- vestigated by using the stochastic averaging method. The averaged generalized It6 stochastic differential equation and Fokkerlanck-Kolmogorov （FPK） equation are derived for prey-predator ecosystem driven by Poisson white noise. Approximate stationary solution for the averaged generalized FPK equation is obtained by using the perturbation method. The effect of prey self-competition parameter e2s on ecosystem behavior is evaluated. The analytical result is confirmed by corresponding Monte Carlo （MC） simulation.

关键词： Prey-predator ecosystem Poisson white noise Stochastic averaging- Approximate stationary solution. Per turbation method

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Defect chemistry and thermal conductivity of the εSmO_(1.5)·(1−ε)ZrO_(2)(0.2≤ε≤0.65)ceramics:Effect of the nonstoichiometry

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Journal of Advanced Ceramics 2024年第11期13卷 1823-1834页

作者： Zhixue Qu Tong Zhang wei pan Key Laboratory of Advanced Functional Materials Education Ministry of ChinaCollege of Materials Science and EngineeringBeijing University of TechnologyBeijing 100124China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Rare-earth zirconate pyrochlores,which exhibit various interesting properties,especially low thermal conductivity,are of great *** is an effective strategy involving defect engineering to reduce the thermal conductivity of *** this work,a long series of solid solutions,εSmO_(1.5)·(1−ε)ZrO_(2)(ε=0.200,0.250,0.350,0.400,0.450,0.500,0.525,0.550,0.600,and 0.650),were designed and synthesized to investigate the effects of nonstoichiometry on the structural evolution,defect chemistry,and thermal conductivity of SmO_(1.5)–ZrO_(2) system across the entire pyrochlore phase field and phase transition *** similarity of all the Raman spectra provides an incredible opportunity to confirm the structural details and evolution of pyrochlore and defective fluorite,as well as the emergence of the expected point defects.A new solution mechanism concerning nonstoichiometry was proposed and confirmed by analyzing the variations in the experimental density and Raman *** thermal conductivities of all the samples were measured,and investigated in terms of the phonon-scattering *** results show that the nonstoichiometry with SmO1.5 excess is more effective in reducing the thermal conductivity to an extremely low value of approximately 1 W/(m·K),which can be attributed to the dramatic decrease in the average acoustic velocity in addition to the strong phonon scattering of Zr ion vacancies and oxygen *** the other hand,the nonstoichiometry with ZrO_(2) excess significantly reduces the thermal conductivity at room temperature,but conversely leads to a slight increase of it above 200°*** former variation can be attributed to the phonon scattering of the 8a interstitial oxygen ions,which has a similar effectiveness to the defects on the SmO1.5-rich *** latter variation may be attributed to the Umklapp scattering of phonons.

关键词： nonstoichiometry pyrochlore rare-earth zirconate thermal conductivity defect chemistry

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Real-time OHT Dispatching Mechanism for the Interbay Automated Material Handling System with Shortcuts and Bypasses

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Chinese Journal of Mechanical Engineering 2017年第3期30卷 663-675页

作者： Cong pan Jie ZHANG wei QIN school of mechanical engineering shanghai jiao tong universityShanghai 200240China

As a key to improve the performance of the interbay automated material handling system （AMHS） in 300 mm semiconductor wafer fabrication system, the real- time overhead hoist transport （OHT） dispatching problem has received much attention. This problem is first formu- lated as a special form of assignment problem and it is proved that more than one solution will be obtained by Hungarian algorithm simultaneously. Through proposing and strictly proving two propositions related to the char- acteristics of these solutions, a modified Hungarian algo- rithm is designed to distinguish these solutions. Finally, a new real-time OHT dispatching method is carefully designed by implementing the solution obtained by the modified Hungarian algorithm. The experimental results of discrete event simulations show that, compared with con- ventional Hungarian algorithm dispatching method, the proposed dispatching method that chooses the solution with the maximum variance respectively reduces on average 4 s of the average waiting time and average lead time of wafer lots, and its performance is rather stable in multiple dif- ferent scenarios of the interbay AMHS with different quantities of shortcuts. This research provides an efficient real-time OHT dispatching mechanism for the interbay AMHS with shortcuts and bypasses.

关键词： Interbay automated material handling system(AMHS) ~ Shortcuts and bypasses - Dispatching ~Hungarian algorithm ~ Wafer fabrication

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A Novel Trustworthiness Measurement Model Based on weight and User Feedback

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Chinese Journal of Electronics 2022年第4期31卷 612-625页

作者： ZHOU wei MA Yanfang pan Haiyu School of Computer Science and Technology Huaibei Normal University School of Computer Science and Information Engineering Changzhou Institute of Technology School of Computer Science and Information Security Guilin University of Electronic Technology

Software trustworthiness is an essential criterion for evaluating software quality. In componentbased software, different components play different roles and different users give different grades of trustworthiness after using the software. The two elements will both affect the trustworthiness of software. When the software quality is evaluated comprehensively, it is necessary to consider the weight of component and user feedback. According to different construction of components, the different trustworthiness measurement models are established based on the weight of components and user feedback. Algorithms of these trustworthiness measurement models are designed in order to obtain the corresponding trustworthiness measurement value automatically. The feasibility of these trustworthiness measurement models is demonstrated by a train ticket purchase system.

关键词： Component-based software Trustworthiness weight User feedback Measurement

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基于红外与可见光视觉的高炉铁口铁水温度场在线检测

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自动化学报 2025年第2期51卷 343-355页

作者：潘冬许川龚芃旭蒋朝辉桂卫华中南大学自动化学院

高炉铁口铁水温度场(Molten iron temperature field, MITF)是表征铁水质量、判断炉温状况的重要信息.然而高炉出铁场动态粉尘的干扰使得铁水温度场的在线准确获取充满挑战.为此,首次提出基于红外与可见光视觉的高炉铁口铁水温度场检测... 详细信息

高炉铁口铁水温度场(Molten iron temperature field, MITF)是表征铁水质量、判断炉温状况的重要信息.然而高炉出铁场动态粉尘的干扰使得铁水温度场的在线准确获取充满挑战.为此,首次提出基于红外与可见光视觉的高炉铁口铁水温度场检测方法,利用可见光图像为红外视觉测温提供先验粉尘干扰情况.首先,设计红外与可见光视觉协同的测温系统,同步获取高炉铁口铁水流的红外图像和可见光图像,铁水流红外图像表征铁水原始温度场信息,可见光图像为量化粉尘透射率提供数据基础.其次,构建基于色彩一致性的可见光图像中粉尘透射率估计模型和基于雾线先验的红外图像中粉尘透射率估计模型,得到红外波段下粉尘透射率.最后,结合红外辐射测温原理,构建基于粉尘透射率的红外测温近似补偿模型,实现铁水温度场的针对性补偿,获取误差较小的铁水温度.工业实验表明,相比于仅利用红外视觉测量铁水温度场,所提方法能够显著降低粉尘造成的测温误差,为高炉调控提供连续可靠的铁水温度数据.

关键词：高炉炼铁铁水温度场红外视觉透射率估计温度补偿

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Association between intra-pancreatic fat deposition and diseases of the exocrine pancreas: A narrative review

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World Journal of Gastroenterology 2025年第2期31卷 27-41页

作者： Jing Ye Jian-Guo Wang Rong-Qiang Liu Qiao Shi wei-Xing Wang Department of General Surgery Renmin Hospital of Wuhan UniversityWuhan 430060Hubei ProvinceChina Department of pancreatic Surgery Renmin Hospital of Wuhan UniversityWuhan 430060Hubei ProvinceChina

Intrapancreatic fat deposition(IPFD)has garnered increasing attention in recent *** prevalence of IPFD is relatively high and associated with factors such as obesity,age,and ***,the pathophysiological mechanisms underlying IPFD remain unclear,with several potential contributing factors,including oxida-tive stress,alterations in the gut microbiota,and hormonal *** was found to be highly correlated with the occurrence and prognosis of exocrine pan-creatic *** imaging techniques remain the primary diagnostic approach for IPFD,an expanding array of biomarkers and clinical scoring systems have been identified for screening ***,effective treatments for IPFD are not available;however,existing medications,such as glucagon-like peptide-1 receptor agonists,and new therapeutic approaches explored in animal models have shown considerable potential for managing this *** paper reviews the pathogenesis of IPFD,its association with exocrine pancreatic disea-ses,and recent advancements in its diagnosis and treatment,emphasizing the significant clinical relevance of IPFD.

关键词： Intrapancreatic fat deposition pancreatic steatosis Nonalcoholic fatty pancreas disease pancreatitis pancreatic cancer

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Drainage-induced ground response in a twin-tunnel system through analytical prediction over the seepage field

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Underground Space 2022年第3期7卷 408-418页

作者： Cheng-wei Zhu wei Wu Hong-wei Ying Xiao-nan Gong pan-pan Guo Research Center of Coastal and Urban Geotechnical Engineering HangzhouChina Institut fur Geotechnik Universitat fur BodenkulturFeistmantelstrasse 4A-1180 ViennaAustria Institute of Geotechinical Engineering Hohai UniversityNanjingChina

Leakage-induced hydraulic and ground responses in a twin-tunnel system are analyzed via the proposed analytical solution on the seepage *** seepage continuity conditions are rigorously satisfied at the interface between the ground and the tunnel lining,in terms of both water pressure and seepage *** analytical solution is verified by comparing the results of numerical simulations.A detailed parametric analysis is carried out to explore the effect of tunnels’spatial layouts and degraded waterproof facilities on leakageinduced hydraulic and ground response,including head decline,water inflow and ground surface *** results show that the often used single tunnel model tends to overestimate the pore pressure on the lining along with water inflow into the tunnel,and underestimate the leakage-induced ground settlement.

关键词： Twin tunnel Leakage Head decline Water inflow Ground settlement

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Rethinking the Encoder-decoder Structure in Medical Image Segmentation from Releasing Decoder Structure

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Journal of Bionic Engineering 2024年第3期21卷 1511-1521页

作者： Jiajia Ni wei Mu An pan Zhengming Chen School of Artificial Intelligence Anhui Polytechnic UniversityWuhu241000China School of Information Science and Engineering HoHai UniversityChangzhou213000China

Medical image segmentation has witnessed rapid advancements with the emergence of encoder-decoder based *** the encoder-decoder structure,the primary goal of the decoding phase is not only to restore feature map resolution,but also to mitigate the loss of feature information incurred during the encoding ***,this approach gives rise to a challenge:multiple up-sampling operations in the decoder segment result in the loss of feature *** address this challenge,we propose a novel network that removes the decoding structure to reduce feature information loss(CBL-Net).In particular,we introduce a Parallel Pooling Module(PPM)to counteract the feature information loss stemming from conventional and pooling operations during the encoding ***,we incorporate a Multiplexed Dilation Convolution(MDC)module to expand the network's receptive ***,although we have removed the decoding stage,we still need to recover the feature map ***,we introduced the Global Feature Recovery(GFR)*** uses attention mechanism for the image feature map resolution recovery,which can effectively reduce the loss of feature *** conduct extensive experimental evaluations on three publicly available medical image segmentation datasets:DRIVE,CHASEDB and MoNuSeg *** results show that our proposed network outperforms state-of-the-art methods in medical image *** addition,it achieves higher efficiency than the current network of coding and decoding structures by eliminating the decoding component.

关键词： Medical image segmentation Encoder-decoder architecture Attention mechanisms Releasing decoder architecture Neural network

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