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Black-box membership inference attacks based on shadow model

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The Journal of China Universities of Posts and Telecommunications 2024年第4期31卷 1-16页

作者： han Zhen Zhou wen'an han Xiaoxuan Wu Jie School of Computer Science Beijing University of Posts and TelecommunicationsBeijing 100876China

Membership inference attacks on machine learning models have drawn significant *** current research primarily utilizes shadow modeling techniques,which require knowledge of the target model and training data,practical scenarios involve black-box access to the target model with no available *** training data further complicate the implementation of these *** this paper,we experimentally compare common data enhancement schemes and propose a data synthesis framework based on the variational autoencoder generative adversarial network(VAE-GAN)to extend the training data for shadow ***,this paper proposes a shadow model training algorithm based on adversarial training to improve the shadow model's ability to mimic the predicted behavior of the target model when the target model's information is *** conducting attack experiments on different models under the black-box access setting,this paper verifies the effectiveness of the VAE-GAN-based data synthesis framework for improving the accuracy of membership inference ***,we verify that the shadow model,trained by using the adversarial training approach,effectively improves the degree of mimicking the predicted behavior of the target *** with existing research methods,the method proposed in this paper achieves a 2.improvement in attack accuracy and delivers better attack performance.

关键词： machine learning membership inference attack shadow model black-box model

Galerkin-based quasi-smooth manifold element(QSME)method for anisotropic heat conduction problems in composites with complex geometry

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 137-154页

作者： Pan WANG Xiangcheng han Weibin wen Baolin WANG Jun LIANG School of Civil Engineering Central South UniversityChangsha 410083China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China School of Science Harbin Institute of TechnologyShenzhen 518055Guangdong ProvinceChina

The accurate and efficient analysis of anisotropic heat conduction problems in complex composites is crucial for structural design and performance evaluation. Traditional numerical methods, such as the finite element method(FEM), often face a trade-off between calculation accuracy and efficiency. In this paper, we propose a quasi-smooth manifold element(QSME) method to address this challenge, and provide the accurate and efficient analysis of two-dimensional(2.) anisotropic heat conduction problems in composites with complex geometry. The QSME approach achieves high calculation precision by a high-order local approximation that ensures the first-order derivative *** results demonstrate that the QSME method is robust and stable, offering both high accuracy and efficiency in the heat conduction analysis. With the same degrees of freedom(DOFs), the QSME method can achieve at least an order of magnitude higher calculation accuracy than the traditional FEM. Additionally, under the same level of calculation error, the QSME method requires 10 times fewer DOFs than the traditional FEM. The versatility of the proposed QSME method extends beyond anisotropic heat conduction problems in complex composites. The proposed QSME method can also be applied to other problems, including fluid flows, mechanical analyses, and other multi-field coupled problems, providing accurate and efficient numerical simulations.

关键词： anisotropic heat conduction quasi-smooth manifold element(QSME) composite with complex geometry numerical simulation finite element method(FEM)

Carbon efficiency modeling and optimization of solar-powered cellular networks

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Science China(Information Sciences) 2024年第5期67卷 228-243页

作者： Yuxi ZHAO Xiaohu GE wen YAN Tao han Yi ZHONG School of Electronic Information and Communications Huazhong University of Science and Technology Huawei Technology Co. Ltd.

As wireless communication traffic experiences rapid growth, the carbon emissions caused by the communication industry are also on the rise. To achieve “carbon neutrality”, researchers are considering the use of renewable energy sources to power cellular networks, thereby reducing carbon emissions. However, a challenge arises when using renewable energy, specifically owing to the unpredictable nature of both the energy consumption of the cellular network and the power generation from renewable sources. This inconsistency results in low renewable energy utilization and reduced carbon efficiency. Herein, we construct a carbon efficiency model of solar-powered cellular networks using practical data from solar radiation. We propose a mechanism that alternately optimizes the performance of the renewable energy network and the cellular network. This approach is based on convex optimization theory and the Dinkelback algorithm, and it leads to the design of a carbon efficiency optimization algorithm. This algorithm aims to improve the carbon efficiency of cellular networks and reduce their carbon emissions. Simulation results demonstrate that our optimization scheme yields a maximum improvement of 2.56 × 108bps/g in the carbon efficiency of the cellular network as compared to conventional power allocation schemes such as the traditional water filling method and heuristic energy sharing and charge/discharge algorithms.

关键词： cellular networks renewable energy carbon efficiency convex optimization theory dinkelbach

Interplay between geometric and electronic structures of Pt entities over TiO_(2. for CO oxidation

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Science China Chemistry 2024年第2期67卷 705-714页

作者： Xixiong Zhang wen Shi Shaobo han Yong Li wenjie Shen School of Chemistry Dalian University of TechnologyDalian116024China State Key Laboratory of Catalysis Dalian Institution of Chemical PhysicsChinese Academy of SciencesDalian116023China

Monodispersed Pt colloids with a mean size of 2.nm were deposited uniformly on the {110} facets of a rod-shaped rutile TiO_(2.,forming a well-defined Pt/TiO_(2. *** treatment of this precursor at elevated temperatures re-dispersed the Pt particles into clusters and ***-calcination at 673 K partially oxidized the Pt particle surface,while calcination at 773 K yielded Pt Oxclusters of 1.6 nm in 7–8 atomic *** calcination at 873 K formed a mixture of raft-like PtO_(x) clusters(1.6 nm,1–2.atomic layers) and cationic *** tested for CO oxidation at 373 K,the Pt particles showed a higher activity than the Pt Oxclusters,whereas the cationic single-atoms were much less *** H_(2.-reduction at 473 K converted the partially oxidized Pt particles into the metallic species,but they were encapsulated by TiO_(2.–xoverlayers because of the strong metal–support interactions,which decreased the activity dramatically.H_(2.-reduction of the PtO_(x) clusters at473 K enhanced the fraction of metallic Pt species without changing the size and geometry,and promoted the activity substantially.H_(2.-treatment of Pt single-atoms at 473 K increased the activity only moderately because most Pt species still kept at cationic *** results straightforwardly differentiated the catalytic behavior of Pt particles,clusters and single-atoms at the same metal loading and over the same TiO_(2. support,and further demonstrated that the electronic structures of Pt entities played a decisive role in the catalytic oxidation,in addition to the specified sizes.

关键词： Pt/TiO_(2.catalyst size effect Pt clusters active sites electronic structures CO oxidation

Online Monitoring Method for Junction Temperature of SiC MOSFETs based on Temperature Sensitive Electrical Parameter

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1799-1807页

作者： han Cao Puqi Ning Yunhao Huang Xuhui wen Wuhan Second Ship Design and Research Institute Wuhan 430205China Key Laboratory of Power Electronics and Electric Drive Institute of Electrical EngineeringChinese Academy of SciencesBeijing 100190China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Collaborative Innovation Center of Electric Vehicles in Beijing Beijing 100081China

Compared to Si devices,the junction temperature of SiC devices is more critical due to the reliability concern introduced by immature packaging technology applied to new *** paper proposes a practical SiC MOSFET junction temperature monitoring method based on the on-state voltage$\\boldsymbol{V}_{\\mathbf{ds}(\\mathbf{on})}$*** Section II of the paper,the temperature sensitivity of the on-state voltage$\\boldsymbol{V}_{\\mathbf{ds}(\\mathbf{on})}$is *** hardware of the measurement system is set up in Section III,which consists of an On-state Voltage Measurement Circuit(OVMC),the sampling and isolation ***,a calibration method based on the self-heating of the SiC MOSFET chip is presented in Section *** the final Section,the junction temperature is monitored synchronously according to the calibration *** proposed method is applied to a Buck converter and verified by both an Infrared Radiation(IR)camera and a Finite Element Analysis(FEA)tool.

关键词： Junction temperature Silicon Carbide(SiC)MOSFET TSEP

Innovative construction of macroporous–mesoporous structured spherical alumina and its hydrothermal stability

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Particuology 2024年第7期90卷 429-435页

作者： Yufan Mo Chunli Li Huiyu Li Wei han He wen Yinghong han Chunxia Che Yongjun Feng State Key Laboratory of Chemical Resource Engineering Beijing Engineering Center for Hierarchical CatalystsCollege of ChemistryBeijing University of Chemical TechnologyBeijing100029China Lanzhou Petrochemical Research Center Petrochemical Research InstitutePetroChinaLanzhou730060China

The pore structure of spherical alumina supports is closely related to the dispersion of catalytically active components and the diffusion of *** excellent pore structure under strict reaction conditions is of utmost *** this work,sphericalγ-Al_(2.O_(3)support with a bimodal pore structure,composed of macropores and mesopores,was successfully synthesized using dodecane as the pore-forming agent through the oil–ammonia column-shaping *** morphology and internal pore structure of the alumina were found to be influenced by the amount of surfactant added and ultrasound treatment ***,when concentration of surfactant was 4‰and ultrasound voltage of 2. V was applied,the resultingγ-Al_(2.O_(3)-4‰-2. displayed a highly concentrated distribution of macropores with an average pore size of 100 nm,resulting in an impressive porosity of 69.2.%.In contrast,the untreated sample ofγ-Al_(2.O_(3)-0-0 only exhibited a mesoporous distribution with a porosity of 54.03%.Moreover,after being subjected to a hydrothermal treatment in a high temperature(600°C)and high humidity(water vapor)environment for 12. h,theγ-Al_(2.O_(3)-4‰-2. sample maintained a high BET specific surface area of 170.9 m^(2.g^(−1)and mercury intrusion porosimetry specific surface area of 2.3.3 m^(2.g^(−1).

关键词： Spherical alumina supports Pore-forming agent Oil-ammonia column shaping method Hydrothermal treatment Hydrothermal stability

Dynamic simulation analysis of molten salt reactor-coupled air-steam combined cycle power generation system

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Nuclear Science and Techniques 2024年第2期35卷 222-233页

作者： Jing-Lei Huang Guo-Bin Jia Li-Feng han wen-Qian Liu Li Huang Zheng-han Yang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

A nonlinear dynamic simulation model based on coordinated control of speed and flow rate for the molten salt reactor and combined cycle systems is proposed here to ensure the coordination and stability between the molten salt reactor and power *** model considers the impact of thermal properties of fluid variation on accuracy and has been validated with *** study reveals the capability of the control system to compensate for anomalous situations and maintain shaft stability in the event of perturbations occurring in high-temperature molten salt tank outlet ***,the control system’s impact on the system’s dynamic characteristics under molten salt disturbance is also *** results reveal that after the disturbance occurs,the controlled system benefits from the action of the control,and the overshoot and disturbance amplitude are positively correlated,while the system power and frequency eventually return to the initial *** simulation model provides a basis for utilizing molten salt reactors for power generation and maintaining grid stability.

关键词： Molten salt reactor Combined cycle Dynamic characteristic Control

Review on the plastic instability of medium -Mn steels for identifying the formation mechanisms of Lüders and Portevin -Le Chatelier bands

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1285-1297页

作者： Bin Hu han Sui Qinghua wen Zheng Wang Alexander Gramlich Haiwen Luo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Steel Institute RWTH Aachen UniversityIntzestraße 152072 AachenGermany

Plastic instability,including both the discontinuous yielding and stress serrations,has been frequently observed during the tensile deformation of medium-Mn steels(MMnS)and has been intensively studied in recent ***,research results are controversial,and no consensus has been achieved regarding the ***,we first summarize all the possible factors that affect the yielding and flow stress serrations in MMnS,including the morphology and stability of austenite,the feature of the phase interface,and the deformation ***,we propose a universal mechanism to explain the conflicting experimental *** conclude that the discontinuous yielding can be attributed to the lack of mobile dislocation before deformation and the rapid dislocation multiplication at the beginning of plastic ***,the results show that the stress serrations are formed due to the pinning and depinning between dislocations and interstitial atoms in ***-induced martensitic transformation,influenced by the mechanical stability of austenite grain and deformation parameters,should not be the intrinsic cause of plastic ***,it can intensify or weaken the discontinuous yielding and the stress serrations by affecting the mobility and density of dislocations,as well as the interaction between the interstitial atoms and dislocations in austenite grains.

关键词： medium manganese steel discontinuous yielding stress serrations retained austenite dislocations

Advances in depressants for flotation separation of Cu–Fe sulfide minerals at low alkalinity:A critical review

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 1-17页

作者： Qicheng Feng wenhang Yang Maohan Chang Shuming wen Dianwen Liu Guang han State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Faculty of Land Resource EngineeringKunming University of Science and TechnologyKunming 650093China Yunnan Key Laboratory of Green Separation and Enrichment of Strategic Mineral Resources Kunming University of Science and TechnologyKunming 650093China

The flotation separation of Cu–Fe sulfide minerals at low alkalinity can be achieved using selective *** the flotation system of Cu–Fe sulfide minerals,depressants usually preferentially interact with the pyrite surface to render the mineral surface hydrophilic and hinder the adsorption of the *** review summarizes the advances in depressants for the flotation separation of Cu–Fe sulfide minerals at low *** advances include use of inorganic depressants (oxidants and sulfur–oxygen compounds),natural polysaccharides (starch,dextrin,konjac glucomannan,and galactomannan),modified polymers (carboxymethyl cellulose,polyacrylamide,lignosulfonate,and tricarboxylate sodium starch),organic acids (polyglutamic acid,sodium humate,tannic acid,pyrogallic acid,salicylic acid,and lactic acid),sodium dimethyl dithiocarbamate,and *** potential application of specific inorganic and organic depressants in the flotation separation of Cu–Fe sulfide minerals at low alkalinity is *** advances in the use of organic depressants with respect to the flotation separation of Cu–Fe sulfide minerals are comprehensively ***,the depression performances and mechanisms of different types of organic depressants on mineral surfaces are ***,several perspectives on depressants vis-à-vis flotation separation of Cu–Fe sulfide minerals at low alkalinity are proposed.

关键词： Cu–Fe sulfide minerals flotation separation selective depressants depression mechanism