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Secured-FL:Blockchain-Based Defense against Adversarial Attacks on Federated Learning Models
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作者 Bello Musa Yakubu Nor Shahida Mohd Jamail +1 位作者 Rabia Latif Seemab Latif 《Computers, Materials & Continua》 2026年第3期734-757,共24页
Federated Learning(FL)enables joint training over distributed devices without data exchange but is highly vulnerable to attacks by adversaries in the form of model poisoning and malicious update injection.This work pr... Federated Learning(FL)enables joint training over distributed devices without data exchange but is highly vulnerable to attacks by adversaries in the form of model poisoning and malicious update injection.This work proposes Secured-FL,a blockchain-based defensive framework that combines smart contract-based authentication,clustering-driven outlier elimination,and dynamic threshold adjustment to defend against adversarial attacks.The framework was implemented on a private Ethereum network with a Proof-of-Authority consensus algorithm to ensure tamper-resistant and auditable model updates.Large-scale simulation on the Cyber Data dataset,under up to 50%malicious client settings,demonstrates Secured-FL achieves 6%-12%higher accuracy,9%-15%lower latency,and approximately 14%less computational expense compared to the PPSS benchmark framework.Additional tests,including confusion matrices,ROC and Precision-Recall curves,and ablation tests,confirm the interpretability and robustness of the defense.Tests for scalability also show consistent performance up to 500 clients,affirming appropriateness to reasonably large deployments.These results make Secured-FL a feasible,adversarially resilient FL paradigm with promising potential for application in smart cities,medicine,and other mission-critical IoT deployments. 展开更多
关键词 Federated learning(FL) blockchain FL based privacy model defense FL model security ethereum smart contract
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Preparation of low-expansion high-performance Si-C composites based on porous advantage of detoxified and purified waste cathode graphite blocks
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作者 Guoqing Yu Mingzhuang Xie +4 位作者 Zhihao Zheng Zegang Wu Yi Wang Hongliang Zhao Fengqin Liu 《International Journal of Minerals,Metallurgy and Materials》 2026年第2期716-726,共11页
Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphi... Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials. 展开更多
关键词 waste graphitization cathode carbon blocks defect advantage silicon/carbon anode materials hazardous waste resource util-ization
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FDEFusion:End-to-End Infrared and Visible Image Fusion Method Based on Frequency Decomposition and Enhancement
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作者 Ming Chen Guoqiang Ma +3 位作者 Ping Qi Fucheng Wang Lin Shen Xiaoya Pi 《Computers, Materials & Continua》 2026年第4期817-839,共23页
In the image fusion field,fusing infrared images(IRIs)and visible images(VIs)excelled is a key area.The differences between IRIs and VIs make it challenging to fuse both types into a high-quality image.Accordingly,eff... In the image fusion field,fusing infrared images(IRIs)and visible images(VIs)excelled is a key area.The differences between IRIs and VIs make it challenging to fuse both types into a high-quality image.Accordingly,efficiently combining the advantages of both images while overcoming their shortcomings is necessary.To handle this challenge,we developed an end-to-end IRI andVI fusionmethod based on frequency decomposition and enhancement.By applying concepts from frequency domain analysis,we used the layering mechanism to better capture the salient thermal targets from the IRIs and the rich textural information from the VIs,respectively,significantly boosting the image fusion quality and effectiveness.In addition,the backbone network combined Restormer Blocks and Dense Blocks;Restormer blocks utilize global attention to extract shallow features.Meanwhile,Dense Blocks ensure the integration between shallow and deep features,thereby avoiding the loss of shallow attributes.Extensive experiments on TNO and MSRS datasets demonstrated that the suggested method achieved state-of-the-art(SOTA)performance in various metrics:Entropy(EN),Mutual Information(MI),Standard Deviation(SD),The Structural Similarity Index Measure(SSIM),Fusion quality(Qabf),MI of the pixel(FMI_(pixel)),and modified Visual Information Fidelity(VIF_(m)). 展开更多
关键词 Infrared images visible images frequency decomposition restormer blocks global attention
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Enhanced Capacity Reversible Data Hiding Based on Pixel Value Ordering in Triple Stego Images
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作者 Kim Sao Nguyen Ngoc Dung Bui 《Computers, Materials & Continua》 2026年第1期1571-1586,共16页
Reversible data hiding(RDH)enables secret data embedding while preserving complete cover image recovery,making it crucial for applications requiring image integrity.The pixel value ordering(PVO)technique used in multi... Reversible data hiding(RDH)enables secret data embedding while preserving complete cover image recovery,making it crucial for applications requiring image integrity.The pixel value ordering(PVO)technique used in multi-stego images provides good image quality but often results in low embedding capability.To address these challenges,this paper proposes a high-capacity RDH scheme based on PVO that generates three stego images from a single cover image.The cover image is partitioned into non-overlapping blocks with pixels sorted in ascending order.Four secret bits are embedded into each block’s maximum pixel value,while three additional bits are embedded into the second-largest value when the pixel difference exceeds a predefined threshold.A similar embedding strategy is also applied to the minimum side of the block,including the second-smallest pixel value.This design enables each block to embed up to 14 bits of secret data.Experimental results demonstrate that the proposed method achieves significantly higher embedding capacity and improved visual quality compared to existing triple-stego RDH approaches,advancing the field of reversible steganography. 展开更多
关键词 RDH reversible data hiding PVO RDH base three stego images
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Evolution of STBC-Based OFDM-IM for Wireless Vehicular Communication
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作者 Tanairat Mata Pisit Boonsrimuang 《China Communications》 2026年第2期51-68,共18页
This paper studies wireless vehicular communication(VehCom)in intelligent transportation systems using an orthogonal frequency division multiplexing with index modulation(OFDM-IM).In the concept of IM,data is transmit... This paper studies wireless vehicular communication(VehCom)in intelligent transportation systems using an orthogonal frequency division multiplexing with index modulation(OFDM-IM).In the concept of IM,data is transmitted not only through the modulated symbols but also via the indices of the active subcarriers.In contrast to the original OFDM,OFDM-IM activates only non-zero subcarriers,increasing energy efficiency.However,the pilotassisted channel estimation(CE)method is a significant challenge in OFDM-IM,where the desired pilot subcarrier interval is related to the OFDM-IM subblock length.This paper proposes a walsh-scattered pilot-assisted CE for OFDM-IM VehCom.The optimum walsh-scattered pilot assignment is proposed to improve the transmission efficiency.Furthermore,a space-time block code with a high transmit diversity gain is employed for OFDM-IM VehCom to enhance VehCom's signal quality.The results show that the proposed method performs higher CE accuracy and better bit-error rate with significant spectral and energy efficiencies than conventional methods. 展开更多
关键词 index modulation intelligent transportation systems pilot-assisted channel estimation space-time block code wireless vehicular communication
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Towards mechanism-based tau-targeted therapies
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作者 Lidia Bakota Roland Brandt 《Neural Regeneration Research》 2026年第2期687-688,共2页
Tau plays a crucial role in several neurodegenerative diseases,collectively referred to as tauopathies.Therefore,targeting potential pathological changes in tau could enable useful therapeutic interventions.However,ta... Tau plays a crucial role in several neurodegenerative diseases,collectively referred to as tauopathies.Therefore,targeting potential pathological changes in tau could enable useful therapeutic interventions.However,tau is not an easy target because it dynamically interacts with microtubules and other cellular components,which presents a challenge for tau-targeted drugs.New cellular models could aid the development of mechanism-based tau-targeted therapies. 展开更多
关键词 tau targeted therapies cellular components mechanism based therapies cellular componentswhich cellular models MICROTUBULES TAUOPATHIES neurodegenerative diseasescollectively
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Correction:Flux‑based assessment of ozone visible foliar injury in Southern Alps
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作者 Elena Marra Alessandra De Marco +8 位作者 Andrea Ebone Anna Maria Ferrara Fabio Giannetti Francesco Tagliaferro Pierre Sicard Andrei Popa Ionel Popa Elena Paoletti Yasutomo Hoshika 《Journal of Forestry Research》 2026年第2期305-305,共1页
Correction to:Journal of Forestry Research(2025)36:124 https://doi.org/10.1007/s11676-025-01918-8 In this article the author’s name Yasutomo Hoshika was incorrectly written as Yasutoma Hoshika.The original article ha... Correction to:Journal of Forestry Research(2025)36:124 https://doi.org/10.1007/s11676-025-01918-8 In this article the author’s name Yasutomo Hoshika was incorrectly written as Yasutoma Hoshika.The original article has been corrected. 展开更多
关键词 visible foliar injury southern Alps flux based assessment yasutomo hoshika journal forestry research yasutoma hoshikathe OZONE
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Height-based biomass models differ for naturally regenerated and planted young trees
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作者 Peter Marcis Jozef Pajtík +1 位作者 Bohdan Konôpka Martin Lukac 《Forest Ecosystems》 2026年第1期178-187,共10页
This study investigated biomass allocation in young stands of European beech(Fagus sylvatica L.)and Norway spruce(Picea abies(L.)Karst.)across 31 forest sites in the Western Carpathians,Slovakia.A total of 541 trees a... This study investigated biomass allocation in young stands of European beech(Fagus sylvatica L.)and Norway spruce(Picea abies(L.)Karst.)across 31 forest sites in the Western Carpathians,Slovakia.A total of 541 trees aged 2–10 years,originating from natural regeneration and planting,were destructively sampled to quantify biomass in four components:foliage,branches,stems,and roots.Generalized non-linear least squares(GNLS)models with a weighing variance function outperformed log-transformed seemingly unrelated regression(SUR)models in terms of accuracy and robustness,especially for foliage and branch biomass.When using height as the predictor,SUR models tended to underestimate biomass in planted beech,leading to notable underprediction of aboveground and total biomass.Biomass allocation patterns varied significantly by species and regeneration origin.Using a non-linear system of equations and component ratio modelling,we found out that planted spruce displayed low variability and a consistent dominance of needle biomass,while naturally regenerated beech showed greater variability and a higher proportion of stem biomass,reflecting stronger competition-driven vertical growth.Interspecific differences in total biomass were more pronounced when using tree height,with spruce generally exhibiting greater biomass than beech at equivalent heights.Overall,stem base diameter marginally outperformed tree height as a predictor of biomass.However,tree height-based models showed strong performance and are particularly suitable for integration with remote sensing applications.These findings can directly support forest managers and modellers in comparing regeneration methods and biomass estimation approaches for early-stage stand development,carbon accounting,and remote sensing calibration. 展开更多
关键词 European beech Norway spruce Allometric relations Tree height Diameter at base Whole-tree biomass Tree components
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Erratum:Marine Shell-Inspired Laser Surface Texturing:Characterizing the Surface Properties of Co-Based Alloy
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作者 Sefika Kasman Sertan Ozan 《Journal of Bionic Engineering》 2026年第1期551-551,共1页
The original online version of this article was revised:Several errors occurred in the published version of the article.These have now been corrected as follows:Page 2,section"2.2 Laser Texturing Procedure of Sur... The original online version of this article was revised:Several errors occurred in the published version of the article.These have now been corrected as follows:Page 2,section"2.2 Laser Texturing Procedure of Surfaces",line 2:The device name was corrected from"YDFLP-E-50-M8"to"YDFLP-50-M8."Page 3,Section 2.4:The phrase"95%confidence interval"has been corrected to"95%confidence level."Page 3,Figure 1 caption:The phrase"fandg"has been corrected to"f and g."The order"C4 and C12"has been reversed to"C12 and C4,"in accordance with the display order in the figure.Page 4,Figure reference:The phrase"Figs.4c and d"has been corrected to"Figs.5b and c."Page 5,paragraph starting with"The ANOVA results are presented...":The phrase"95%confidence interval"has been corrected to"95%confidence level." 展开更多
关键词 laser surface texturing surface properties marine shell inspired co based alloy laser texturing procedure confidence level ANOVA results
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Home-Based Care Service
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作者 XU JUNXING 《China Today》 2026年第3期70-72,共3页
Hebei Province has incorporated targeted assistance services for people with disabilities into livelihood projects,upgrading the quality and efficiency of support services for disadvantaged groups.THE living and nursi... Hebei Province has incorporated targeted assistance services for people with disabilities into livelihood projects,upgrading the quality and efficiency of support services for disadvantaged groups.THE living and nursing allowances provided by the Chinese government for people with disabilities who are unable to work are not only important components of China’s social security system which provide for the needs of its disabled,but also show China’s ability to guarantee the basic living standard and social fairness and justice for this group of people. 展开更多
关键词 livelihood projects home based care targeted assistance livelihood projectsupgrading people disabilities living nursing allowances targeted assistance services social security system
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Single-Dimensional Encryption Against Stealthy Attacks on Stochastic Event-Based Estimation
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作者 Jun Shang Di Zhao +1 位作者 Hanwen Zhang Dawei Shi 《IEEE/CAA Journal of Automatica Sinica》 2026年第1期233-235,共3页
Dear Editor,This letter studies the problem of stealthy attacks targeting stochastic event-based estimation,alongside proposing measures for their mitigation.A general attack framework is introduced,and the correspond... Dear Editor,This letter studies the problem of stealthy attacks targeting stochastic event-based estimation,alongside proposing measures for their mitigation.A general attack framework is introduced,and the corresponding stealthiness condition is analyzed.To enhance system security,we advocate for a single-dimensional encryption method,showing that securing a singular data element is sufficient to shield the system from the perils of stealthy attacks. 展开更多
关键词 enhance system securitywe securing singular data element single dimensional encryption stochastic event based estimation stealthiness condition security mitigation attack framework stealthy attacks
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Slip rate and locking degree of Haiyuan fault zone,northeastern Qinghai-Xizang plateau,based on refined block model and GPS data
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作者 Yang Liu Yuxuan Qiu +2 位作者 Jialiang Liu Yu Zhang Caijun Xu 《Geodesy and Geodynamics》 2025年第5期536-545,共10页
As a major fault in the northeastern Qinghai-Xizang Plateau,the Haiyuan fault zone is important for understanding the regional deformation.Aiming at the differences in the slip rate and locking degree obtained from di... As a major fault in the northeastern Qinghai-Xizang Plateau,the Haiyuan fault zone is important for understanding the regional deformation.Aiming at the differences in the slip rate and locking degree obtained from different studies,this study constructs a refined block model(including Qilian,Alxa,Ordos,Xining,Haiyuan,and Lanzhou blocks)and uses the grid search and simulated annealing methods to invert GPS data for slip rate and locking degree of the Haiyuan fault zone.The results are as follows:(1)The sinistral slip rates in the western,middle,and eastern segments are 4.93-5.22 mm/a,1.52-4.94 mm/a,and 0.43-1.18 mm/a,decreasing eastward on the whole,while the compression rates are 0.45-1.26 mm/a,0.58-2.62 mm/a,and3.52-4.48 mm/a,increasing eastward on the whole.(2)The locking depth of the western segment increases from about 5 km to about 20 km eastward;the middle segment decreases and then increases eastward;the eastern segment concentrates at about 20 km(PHI is about 0.86).(3)The slip deficit is relatively higher in the Lenglongling,Jinqianghe,Maomaoshan,and Liupanshan faults(averaging about 3.42 mm/a,4.16 mm/a,4.23 mm/a,and 3.43 mm/a within 20 km).(4)The Qilian,Alxa,Xining,Lanzhou,and Haiyuan blocks rotate clockwise,while the Ordos block rotates counterclockwise.Additionally,by comparing different block models,the Haiyuan block should be considered independently.The Haiyuan fault zone adjusts surrounding block movements and uplifts Liupanshan mountain tectonically.The results can provide important references for understanding the regional earthquake risk and deformation mechanism. 展开更多
关键词 Haiyuan fault zone block model Locking degree Slip rate
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Blockchain-Based Framework for Secure Sharing of Cross-Border Trade Data
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作者 Shenjian Xiao Xiaoli Qin +1 位作者 Yanzhao Tian Zhongkai Dang 《Computers, Materials & Continua》 2025年第5期2351-2373,共23页
The advent of the digital age has consistently provided impetus for facilitating global trade,as evidenced by the numerous customs clearance documents and participants involved in the international trade process,inclu... The advent of the digital age has consistently provided impetus for facilitating global trade,as evidenced by the numerous customs clearance documents and participants involved in the international trade process,including enterprises,agents,and government departments.However,the urgent issue that requires immediate attention is how to achieve secure and efficient cross-border data sharing among these government departments and enterprises in complex trade processes.In addressing this need,this paper proposes a data exchange architecture employing Multi-Authority Attribute-Based Encryption(MA-ABE)in combination with blockchain technology.This scheme supports proxy decryption,attribute revocation,and policy update,while allowing each participating entity to manage their keys autonomously,ensuring system security and enhancing trust among participants.In order to enhance system decentralization,a mechanism has been designed in the architecture where multiple institutions interact with smart contracts and jointly participate in the generation of public parameters.Integration with the multi-party process execution engine Caterpillar has been shown to boost the transparency of cross-border information flow and cooperation between different organizations.The scheme ensures the auditability of data access control information and the visualization of on-chain data sharing.The MA-ABE scheme is statically secure under the q-Decisional Parallel Bilinear Diffie-Hellman Exponent(q-DPBDHE2)assumption in the random oracle model,and can resist ciphertext rollback attacks to achieve true backward and forward security.Theoretical analysis and experimental results demonstrate the appropriateness of the scheme for cross-border data collaboration between different institutions. 展开更多
关键词 Multi-authority attribute based encryption blockchain data sharing access control
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Blockchain-based knowledge-aware semantic communications for remote driving image transmission
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作者 Yangfei Lin Tutomu Murase +3 位作者 Yusheng Ji Wugedele Bao Lei Zhong Jie Li 《Digital Communications and Networks》 2025年第2期317-325,共9页
Remote driving,an emergent technology enabling remote operations of vehicles,presents a significant challenge in transmitting large volumes of image data to a central server.This requirement outpaces the capacity of t... Remote driving,an emergent technology enabling remote operations of vehicles,presents a significant challenge in transmitting large volumes of image data to a central server.This requirement outpaces the capacity of traditional communication methods.To tackle this,we propose a novel framework using semantic communications,through a region of interest semantic segmentation method,to reduce the communication costs by transmitting meaningful semantic information rather than bit-wise data.To solve the knowledge base inconsistencies inherent in semantic communications,we introduce a blockchain-based edge-assisted system for managing diverse and geographically varied semantic segmentation knowledge bases.This system not only ensures the security of data through the tamper-resistant nature of blockchain but also leverages edge computing for efficient management.Additionally,the implementation of blockchain sharding handles differentiated knowledge bases for various tasks,thus boosting overall blockchain efficiency.Experimental results show a great reduction in latency by sharding and an increase in model accuracy,confirming our framework's effectiveness. 展开更多
关键词 Semantic communication Remote driving Semantic segmentation blockchain Knowledge base management
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Critical operation range of electro-hydrostatic actuator pumps based on cylinder block tilting states
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作者 Junhui ZHANG Xuguang LI +5 位作者 Fei LYU Felix SCHLEGEL Katharina SCHMITZ Shihao LIU Weidi HUANG Bing XU 《Chinese Journal of Aeronautics》 2025年第12期516-530,共15页
The electro-hydrostatic actuator(EHA)pump is required to operate in a wide range of pressures and speeds to meet the variable output power demands.However,the reliable operation range of EHA pumps is restricted,and th... The electro-hydrostatic actuator(EHA)pump is required to operate in a wide range of pressures and speeds to meet the variable output power demands.However,the reliable operation range of EHA pumps is restricted,and the cylinder block tilting is considered a serious factor.This paper presents an analytical approach for evaluating the critical operation range of EHA pumps based on a criterion for cylinder tilting states.It explicitly reveals the fundamental principle of the cylinder block tilting limiting the operation range.The criterion is verified with the measured tilting angle and leakage flow.Results show that the calculated critical conditions accurately identify the inflection point of performance changes.Beyond the critical operation range,the severe cylinder block tilting leads to a sharp increase in leakage and may even result in a sudden failure.Furthermore,the impacts of the center spring force,the piston-slipper assembly mass,and the position of the spline reaction on the critical operation range are investigated. 展开更多
关键词 EHA pump Critical operation range Cylinder block tilting Tilting criterion Center spring force
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Deep Reinforcement Learning-based Multi-Objective Scheduling for Distributed Heterogeneous Hybrid Flow Shops with Blocking Constraints
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作者 Xueyan Sun Weiming Shen +3 位作者 Jiaxin Fan Birgit Vogel-Heuser Fandi Bi Chunjiang Zhang 《Engineering》 2025年第3期278-291,共14页
This paper investigates a distributed heterogeneous hybrid blocking flow-shop scheduling problem(DHHBFSP)designed to minimize the total tardiness and total energy consumption simultaneously,and proposes an improved pr... This paper investigates a distributed heterogeneous hybrid blocking flow-shop scheduling problem(DHHBFSP)designed to minimize the total tardiness and total energy consumption simultaneously,and proposes an improved proximal policy optimization(IPPO)method to make real-time decisions for the DHHBFSP.A multi-objective Markov decision process is modeled for the DHHBFSP,where the reward function is represented by a vector with dynamic weights instead of the common objectiverelated scalar value.A factory agent(FA)is formulated for each factory to select unscheduled jobs and is trained by the proposed IPPO to improve the decision quality.Multiple FAs work asynchronously to allocate jobs that arrive randomly at the shop.A two-stage training strategy is introduced in the IPPO,which learns from both single-and dual-policy data for better data utilization.The proposed IPPO is tested on randomly generated instances and compared with variants of the basic proximal policy optimization(PPO),dispatch rules,multi-objective metaheuristics,and multi-agent reinforcement learning methods.Extensive experimental results suggest that the proposed strategies offer significant improvements to the basic PPO,and the proposed IPPO outperforms the state-of-the-art scheduling methods in both convergence and solution quality. 展开更多
关键词 Multi-objective Markov decision process Multi-agent deep reinforcement learning Proximal policy optimization Distributed hybrid flow-shop scheduling blocking constraints
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Database-oriented storage based on LMDB and linear octree for massive block model 被引量:6
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作者 毕林 赵辉 贾明涛 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第9期2462-2468,共7页
Data organization requires high efficiency for large amount of data applied in the digital mine system. A new method of storing massive data of block model is proposed to meet the characteristics of the database, incl... Data organization requires high efficiency for large amount of data applied in the digital mine system. A new method of storing massive data of block model is proposed to meet the characteristics of the database, including ACID-compliant, concurrency support, data sharing, and efficient access. Each block model is organized by linear octree, stored in LMDB(lightning memory-mapped database). Geological attribute can be queried at any point of 3D space by comparison algorithm of location code and conversion algorithm from address code of geometry space to location code of storage. The performance and robustness of querying geological attribute at 3D spatial region are enhanced greatly by the transformation from 3D to 2D and the method of 2D grid scanning to screen the inner and outer points. Experimental results showed that this method can access the massive data of block model, meeting the database characteristics. The method with LMDB is at least 3 times faster than that with etree, especially when it is used to read. In addition, the larger the amount of data is processed, the more efficient the method would be. 展开更多
关键词 block model linear octree lightning memory-mapped database mass data access digital mine etree
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Early all-zero blocks detecting method for video coding based on novel threshold 被引量:1
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作者 钟国韵 何小海 +1 位作者 吴笛 滕奇志 《Journal of Southeast University(English Edition)》 EI CAS 2011年第3期248-252,共5页
In order to decrease both computational complexity and coding time, an improved algorithm for the early detection of all-zero blocks (AZBs) in H. 264/AVC is proposed. The previous AZBs detection algorithms are revie... In order to decrease both computational complexity and coding time, an improved algorithm for the early detection of all-zero blocks (AZBs) in H. 264/AVC is proposed. The previous AZBs detection algorithms are reviewed. Three types of transformed frequency-domain coefficients, which are quantized to zeros, are analyzed. Based on the three types of frequencydomain scaling factors, the corresponding spatial coefficients are derived. Then the Schwarz inequality is applied to the derivation of the three thresholds based on spatial coefficients. Another threshold is set on the basis of the probability distribution of zero coefficients in a block. As a result, an adaptive AZBs detection algorithm is proposed based on the minimum of the former three thresholds and the threshold of zero blocks distribution. The simulation results show that, compared with the existing AZBs detection algorithms, the proposed algorithm achieves a 5% higher detection ratio in AZBs and 4% to 10% computation saving with only 0. 1 dB video quality degradation. 展开更多
关键词 all-zero block video coding THRESHOLD
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An Incremental Algorithm for Non-Slicing Floorplan Based on Corner Block List Representation 被引量:1
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作者 杨柳 马昱春 +2 位作者 洪先龙 董社勤 周强 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第12期2335-2343,共9页
We present a novel incremental algorithm for non-slicing floorplans based on the corner block list representation. The horizontal and vertical adjacency graphs are derived from the packing of the initial floorplanning... We present a novel incremental algorithm for non-slicing floorplans based on the corner block list representation. The horizontal and vertical adjacency graphs are derived from the packing of the initial floorplanning results. Based on the critical path and the accumulated slack distances we define,we choose the best position for insertion and do a series of operations incrementally, such as deleting modules, adding modules, and resizing modules quickly. This incremental floorplanning algorithm has a very high speed less than 1μm,which is one of the most important measures in this research. The algorithm preserves the original good performances on area and wire length. It can also supply other tools with good physical estimates for area, wire length, and other performance guidelines. 展开更多
关键词 incremental floorplanning corner block list adjacency graph balance node
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Technique of Error Concealment for Block-Based Image Coding Using Genetic Algorithm
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作者 杨守义 罗伟雄 《Journal of Beijing Institute of Technology》 EI CAS 2002年第2期164-168,共5页
Since real world communication channels are not error free, the coded data transmitted on them may be corrupted, and block based image coding systems are vulnerable to transmission impairment. So the best neighborh... Since real world communication channels are not error free, the coded data transmitted on them may be corrupted, and block based image coding systems are vulnerable to transmission impairment. So the best neighborhood match method using genetic algorithm is used to conceal the error blocks. Experimental results show that the searching space can be greatly reduced by using genetic algorithm compared with exhaustive searching method, and good image quality is achieved. The peak signal noise ratios(PSNRs) of the restored images are increased greatly. 展开更多
关键词 block based image coding genetic algorithm error concealment
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