期刊文献+
共找到1,371篇文章
< 1 2 69 >
每页显示 20 50 100
CONTRACTED EFFECT OF BELL-SHADE SHAPE WELDING ARC AND ACCOMPANIED MAGNETIC FIELD WITH SPIRAL PIPE SHAPE 被引量:4
1
作者 Yu Jianrong, Zhang Jiaying , Jiang Lipei, Jiao Xiangdong Beijing Institute of Petrochemical Technology, Beijing 102600 Department of Mechanical Engineering,Tsinghua University, Beijing 100084 Jia Changshen, Shi Yaowu Xi′an Jiaotong University, 《中国有色金属学会会刊:英文版》 CSCD 1997年第2期96-99,共4页
CONTRACTEDEFFECTOFBELLSHADESHAPEWELDINGARCANDACCOMPANIEDMAGNETICFIELDWITHSPIRALPIPESHAPE①YuJianrong,ZhangJia... CONTRACTEDEFFECTOFBELLSHADESHAPEWELDINGARCANDACCOMPANIEDMAGNETICFIELDWITHSPIRALPIPESHAPE①YuJianrong,ZhangJiaying,JiangLipei,... 展开更多
关键词 longitudinal magnetic field BELL SHADE SHAPE welding arc contracted effect ACCOMPANIED magnetic field SPIRAL PIPE SHAPE
在线阅读 下载PDF
Revision rhinoplasty for contracted nose:A systematic review and meta-analysis
2
作者 Yiming Wang Guanhuier Wang +1 位作者 Yonghuan Zhen Yang An 《Chinese Journal of Plastic and Reconstructive Surgery》 2023年第2期100-108,共9页
Background:This study aimed to review treatments and evaluate the aesthetic outcomes,complications,and reoperation rates regarding surgical correction for a postoperative contracted nose.Methods:PubMed,MEDLINE,and Emb... Background:This study aimed to review treatments and evaluate the aesthetic outcomes,complications,and reoperation rates regarding surgical correction for a postoperative contracted nose.Methods:PubMed,MEDLINE,and Embase databases were searched for studies detailing aesthetic outcomes and complications of surgical correction of a contracted nose.Surgical procedures,adjuvant treatment,outcomes,and complications were synthesized and analyzed.Results:Nine articles encompassing 376 patients were included in the systematic review,and six articles(198 participants)were included in the meta-analysis.The most frequently used graft material was the autologous rib cartilage(61.1%).Surgical procedures were heterogeneous in these studies.The nasolabial angle reduced by 9.52°(95%confidence interval(CI):(-11.95,-7.09),P<0.0001),and the nasal length increased significantly(standardized mean difference(SMD)=2.25,95%CI:(1.26,2.23),P<0.00001).However,the evidence was insufficient to determine a significant change in the columellar-labial angle(SMD=-0.95,95%CI:(-2.19,0.29),P=0.13)and columellar-lobular angle(SMD=2.39,95%CI:(-1.20,5.97),P=0.19).Aesthetic dissatisfaction(12.5%)and infection(4.5%)were the most commonly reported complications.Reoperation was performed in 5.3%of patients.Conclusion:Surgical correction can increase the nasal length,reduce the nasolabial angle,and have a low reoperation rate.No significant improvement in the columellar-labial or columellar-lobular angle was observed. 展开更多
关键词 Nasal deformity contracted nose RHINOPLASTY Postoperative complication META-ANALYSIS Systematic review
暂未订购
A randomized clinical trial assessing the efficacy of single and multiple intralesional collagenase injections for treating contracted scars
3
作者 Shuangbai Zhou Poh-Ching Tan +4 位作者 Cheng-An Chiang Yun Xie Peiqi Zhang Qingfeng Li Kai Liu 《Chinese Journal of Plastic and Reconstructive Surgery》 2023年第3期120-125,共6页
Background:Scar contractions caused by trauma or burns can cause secondary physical dysfunction and disfigurement.Many minimally invasive methods for scar contraction have shown limited applicability and efficacy.This... Background:Scar contractions caused by trauma or burns can cause secondary physical dysfunction and disfigurement.Many minimally invasive methods for scar contraction have shown limited applicability and efficacy.This study investigated the feasibility and efficacy of intralesional collagenase injections for scar contraction treatment.Methods:Patients with contracted scars who had limited joint movement and physical disfiguration for>1 year were enrolled in this single-blind,randomized clinical trial from July 2017 to February 2018 at Shanghai Ninth People’s Hospital.Collagenase was injected into the firm-contracted scar(15 U/cm^(2))three times at 4-week intervals in the multiple treatment group and once in the single treatment group,and a placebo injection was performed in the control group.Scar length and skin texture were documented at the 4-and 12-week follow-ups.The safety of the collagenase treatment was also evaluated.Results:The contracted scar was significantly elongated after both single and multiple collagenase treatments.The results showed that,compared to a one-time treatment,repeated injections were more effective at 12 weeks,with an average improvement of 26.83(15.79%).At 12 weeks,78.9% of the patients in the multiple group and 52.9%in the single group achieved significant improvement at 12 weeks.No severe adverse events were observed.Conclusion:Intralesional collagenase injection showed promising results in improving scar contraction and provides an alternative treatment for patients. 展开更多
关键词 contracted scar COLLAGENASE Intralesional injection Functional improvement Clinical trial
暂未订购
Dermis-fat graft for contracted socket reconstruction in an indigenous black population, Southwestern Nigeria
4
作者 Oluyemi Fasina 《Case Reports in Clinical Medicine》 2019年第4期87-92,共6页
The purpose of this case series is to report the indications for dermis-fat grafting and the outcome of treatment in orbital soft tissue contraction among patients in a tertiary center. It is a retrospective, consecut... The purpose of this case series is to report the indications for dermis-fat grafting and the outcome of treatment in orbital soft tissue contraction among patients in a tertiary center. It is a retrospective, consecutive, interventional case series where all patients with orbital soft tissue contraction who had dermis-fat grafting were studied. All nine patients in our series underwent secondary dermis-fat grafting for orbital soft tissue reconstruction. The major cause for contracted socket was surgical eye removal following trauma. Eight of nine patients had no orbital implants inserted at the time of primary eye removal and eight patients have had failed orbital reconstructive procedures. Satisfactory cosmetic results were reported in all patients post-operatively. Dermis-fat grafting for contracted socket reconstruction was found to give satisfactory cosmetic results in our studied population. 展开更多
关键词 Anophthalmic SOCKET contracted SOCKET Dermis-Fat GRAFT NIGERIA Outcome
暂未订购
An adjustable contracted CI method 被引量:2
5
作者 王育彬 甘正汀 +1 位作者 苏克和 文振翼 《Science China Chemistry》 SCIE EI CAS 1999年第6期649-655,共7页
A new contracted CI scheme—adjustable contracted CI scheme—is presented and programed. The efficiency of this scheme is tested by some example calculations. The result shows that the application of the new scheme is... A new contracted CI scheme—adjustable contracted CI scheme—is presented and programed. The efficiency of this scheme is tested by some example calculations. The result shows that the application of the new scheme is flexible and the correlation energy loss is lower than that of the original externally contracted CI method. Keywords: configuration interaction, contracted CI method, correlation energy. 展开更多
关键词 CONFIGURATION INTERACTION contracted CI METHOD CORRELATION energy.
原文传递
Doubly contracted CI method and applications 被引量:3
6
作者 WANG Yubin1, HAN Huixian1, ZHAI Gaohong2 ,SUO Bin1 & WEN Zheny1,2 1. Institute of Modern Physics, Northwest University, Xian 710069, China 2. Laboratory of Physico-Inorganic Chemistry, Department of Chemistry, Northwest University, Xian 710069,China Correspondence should be addressed to Wen Zhenyi 《Science China Chemistry》 SCIE EI CAS 2004年第4期276-282,共7页
Based on the hole-particle correspondence an approximate so-called doubly contracted CI scheme is proposed. Examples calculated based on the doubly contracted CI (DCCI) scheme show that the number of configurations af... Based on the hole-particle correspondence an approximate so-called doubly contracted CI scheme is proposed. Examples calculated based on the doubly contracted CI (DCCI) scheme show that the number of configurations after contraction is reduced by three orders of magnitude, and the computation time is reduced by an order of magnitude. The examples also show that compared with experiments the DCCI and uncontracted CI have similar and reasonable accuracy to some spectroscopic parameters. 展开更多
关键词 doubly contracted CI hole-particle symmetry approximate MRCI
原文传递
Investigating Solutions in Nonlinear Evolution Equations:A Focus on Local Existence in Mixed Types
7
作者 NAFFISA Toureche Trouba FAN Long ABDELGHANI Dahou 《应用数学》 北大核心 2025年第3期691-702,共12页
With the urgent need to resolve complex behaviors in nonlinear evolution equations,this study makes a contribution by establishing the local existence of solutions for Cauchy problems associated with equations of mixe... With the urgent need to resolve complex behaviors in nonlinear evolution equations,this study makes a contribution by establishing the local existence of solutions for Cauchy problems associated with equations of mixed types.Our primary contribution is the establishment of solution existence,illuminating the dynamics of these complex equations.To tackle this challenging problem,we construct an approximate solution sequence and apply the contraction mapping principle to rigorously prove local solution existence.Our results significantly advance the understanding of nonlinear evolution equations of mixed types.Furthermore,they provide a versatile,powerful approach for tackling analogous challenges across physics,engineering,and applied mathematics,making this work a valuable reference for researchers in these fields. 展开更多
关键词 Nonlinear evolution equation Contraction mapping principle Sobolev space Dissipative system
在线阅读 下载PDF
Space-marching inverse design of subsonic,transonic,and supersonic internal flowfields
8
作者 Bo ZHANG Shihe YI +3 位作者 Yuxin ZHAO Rui YANG Ziyuan ZHU Ruitong ZENG 《Chinese Journal of Aeronautics》 2025年第2期15-30,共16页
Flowfield inverse design can obtain the desired flow and contour with high design efficiency,short design cycle,and small modification need.In this study,the Euler equations are formulated in the stream-function coord... Flowfield inverse design can obtain the desired flow and contour with high design efficiency,short design cycle,and small modification need.In this study,the Euler equations are formulated in the stream-function coordinates and combined with the given boundary conditions to derive a gridless space-marching method for the inverse design of subsonic,transonic,and supersonic flowfields.Designers can prescribe the flow parameters along the reference streamline to design flowfields and aerodynamic contours.The method is validated by the theoretical transonic solution,computational fluid dynamics,and experimental data,respectively.The method supports the fabrication of a Mach 2.0 single expansion tunnel.The calibration data agree well with the prescribed pressure distribution.The method is successfully applied to inverse design of contractions,nozzles,and asymmetric channels.Compared to classical analytic contractions,the contractions designed by the space-marching method provide a more accurate transonic flow.Compared to the classical Sivells’nozzle,the nozzle designed by the space-marching method provides a smaller workload,a more flexible velocity distribution,a 20%reduction in length,and an equally uniform flow.Additionally,the space-marching method is applied to design the asymmetric channels under various Mach numbers.These asymmetric channels perfectly eliminate Mach waves,achieving the shock-free flow turning and high flow uniformity.These results validate the feasibility of the space-marching method,making it a good candidate for the inverse design of subsonic,transonic,and supersonic internal flowfields and aerodynamic contours. 展开更多
关键词 Flowfield Inverse design Compressible flow CONTRACTION Nozzle Asymmetric channel
原文传递
Computer Modeling Approaches for Blockchain-Driven Supply Chain Intelligence:A Review on Enhancing Transparency,Security,and Efficiency
9
作者 Puranam Revanth Kumar Gouse Baig Mohammad +4 位作者 Pallati Narsimhulu Dharnisha Narasappa Lakshmana Phaneendra Maguluri Subhav Singh Shitharth Selvarajan 《Computer Modeling in Engineering & Sciences》 2025年第9期2779-2818,共40页
Blockchain Technology(BT)has emerged as a transformative solution for improving the efficacy,security,and transparency of supply chain intelligence.Traditional Supply Chain Management(SCM)systems frequently have probl... Blockchain Technology(BT)has emerged as a transformative solution for improving the efficacy,security,and transparency of supply chain intelligence.Traditional Supply Chain Management(SCM)systems frequently have problems such as data silos,a lack of visibility in real time,fraudulent activities,and inefficiencies in tracking and traceability.Blockchain’s decentralized and irreversible ledger offers a solid foundation for dealing with these issues;it facilitates trust,security,and the sharing of data in real-time among all parties involved.Through an examination of critical technologies,methodology,and applications,this paper delves deeply into computer modeling based-blockchain framework within supply chain intelligence.The effect of BT on SCM is evaluated by reviewing current research and practical applications in the field.As part of the process,we delved through the research on blockchain-based supply chain models,smart contracts,Decentralized Applications(DApps),and how they connect to other cutting-edge innovations like Artificial Intelligence(AI)and the Internet of Things(IoT).To quantify blockchain’s performance,the study introduces analytical models for efficiency improvement,security enhancement,and scalability,enabling computational assessment and simulation of supply chain scenarios.These models provide a structured approach to predicting system performance under varying parameters.According to the results,BT increases efficiency by automating transactions using smart contracts,increases security by using cryptographic techniques,and improves transparency in the supply chain by providing immutable records.Regulatory concerns,challenges with interoperability,and scalability all work against broad adoption.To fully automate and intelligently integrate blockchain with AI and the IoT,additional research is needed to address blockchain’s current limitations and realize its potential for supply chain intelligence. 展开更多
关键词 Blockchain supply chain management TRANSPARENCY SECURITY smart contracts DECENTRALIZATION EFFICIENCY
在线阅读 下载PDF
Effect of food value-chain connections on land-use change
10
作者 P.M.Post Y.Dou A.Nelson 《Geography and Sustainability》 2025年第1期130-142,共13页
Changes in food production,often driven by distant demand,have a significant influence on sustainable man agement and use of land and water,and are in turn a driving factor of biodiversity change.While the connection ... Changes in food production,often driven by distant demand,have a significant influence on sustainable man agement and use of land and water,and are in turn a driving factor of biodiversity change.While the connection between land use and demand through value chains is increasingly understood,there is no comprehensive concep tualisation of this relationship.To address this gap,we propose a conceptual framework and use it as a basis for a systematic review to characterise value-chain connection and explore its influence on land-use and-cover change.Our search in June 2022 onWeb of Science and Scopus yielded 198 documents,describing studies completed after the year 2000 that provide information on both value-chain connection and land-use or-cover change.In total,we used 531 distinct cases to assess how frequently particular types of land-use or-cover change and value-chain connections co-occurred,and synthesized findings on their relations.Our findings confirm that 1)market inte gration is associated with intensification;2)land managers with environmental standards more frequently adopt environmentally friendly practices;3)physical and value-chain distances to consumers play a crucial role,with shorter distances associated with environmentally friendly practices and global chains linked to intensification and expansion.Incorporating these characteristics in existing theories of land-system change,would significantly advance understanding of land managers’decision-making,ultimately guiding more environmentally responsible production systems and contributing to global sustainability goals. 展开更多
关键词 LUCC Contract farming Alternative food network CERTIFICATION Supply chain DEFORESTATION
在线阅读 下载PDF
Block-gram:Mining knowledgeable features for efficiently smart contract vulnerability detection
11
作者 Xueshuo Xie Haolong Wang +3 位作者 Zhaolong Jian Yaozheng Fang Zichun Wang Tao Li 《Digital Communications and Networks》 2025年第1期1-12,共12页
Smart contracts are widely used on the blockchain to implement complex transactions,such as decentralized applications on Ethereum.Effective vulnerability detection of large-scale smart contracts is critical,as attack... Smart contracts are widely used on the blockchain to implement complex transactions,such as decentralized applications on Ethereum.Effective vulnerability detection of large-scale smart contracts is critical,as attacks on smart contracts often cause huge economic losses.Since it is difficult to repair and update smart contracts,it is necessary to find the vulnerabilities before they are deployed.However,code analysis,which requires traversal paths,and learning methods,which require many features to be trained,are too time-consuming to detect large-scale on-chain contracts.Learning-based methods will obtain detection models from a feature space compared to code analysis methods such as symbol execution.But the existing features lack the interpretability of the detection results and training model,even worse,the large-scale feature space also affects the efficiency of detection.This paper focuses on improving the detection efficiency by reducing the dimension of the features,combined with expert knowledge.In this paper,a feature extraction model Block-gram is proposed to form low-dimensional knowledge-based features from bytecode.First,the metadata is separated and the runtime code is converted into a sequence of opcodes,which are divided into segments based on some instructions(jumps,etc.).Then,scalable Block-gram features,including 4-dimensional block features and 8-dimensional attribute features,are mined for the learning-based model training.Finally,feature contributions are calculated from SHAP values to measure the relationship between our features and the results of the detection model.In addition,six types of vulnerability labels are made on a dataset containing 33,885 contracts,and these knowledge-based features are evaluated using seven state-of-the-art learning algorithms,which show that the average detection latency speeds up 25×to 650×,compared with the features extracted by N-gram,and also can enhance the interpretability of the detection model. 展开更多
关键词 Smart contract Bytecode&opcode Knowledgeable features Vulnerability detection Feature contribution
在线阅读 下载PDF
Robust Detection and Analysis of Smart Contract Vulnerabilities with Large Language Model Agents
12
作者 Nishank P. Kuppa Vijay K. Madisetti 《Journal of Information Security》 2025年第1期197-226,共30页
Smart contracts on the Ethereum blockchain continue to revolutionize decentralized applications (dApps) by allowing for self-executing agreements. However, bad actors have continuously found ways to exploit smart cont... Smart contracts on the Ethereum blockchain continue to revolutionize decentralized applications (dApps) by allowing for self-executing agreements. However, bad actors have continuously found ways to exploit smart contracts for personal financial gain, which undermines the integrity of the Ethereum blockchain. This paper proposes a computer program called SADA (Static and Dynamic Analyzer), a novel approach to smart contract vulnerability detection using multiple Large Language Model (LLM) agents to analyze and flag suspicious Solidity code for Ethereum smart contracts. SADA not only improves upon existing vulnerability detection methods but also paves the way for more secure smart contract development practices in the rapidly evolving blockchain ecosystem. 展开更多
关键词 Blockchain Ethereum Smart Contracts Security Decentralized Applications WEB3 Cryptocurrency Large Language Models
在线阅读 下载PDF
Transmutation of zonal twinning dislocations during non-cozone{1011}twin-twin interaction in magnesium
13
作者 Peng Chen Bin Li 《Journal of Magnesium and Alloys》 2025年第2期681-696,共16页
Theoretically,a twinning dislocation must stay on the twinning plane which is the first invariant plane of a twinning mode,because the glide of twinning dislocation linearly transforms the parent lattice to the twin l... Theoretically,a twinning dislocation must stay on the twinning plane which is the first invariant plane of a twinning mode,because the glide of twinning dislocation linearly transforms the parent lattice to the twin lattice.However,recent experimental observations showed that a{1011}{1012}twin variant could cross another variant during twin-twin interaction.It is well known that{1011}twinning is mediated by zonal twinning dislocations.Thus,how the zonal twinning dislocations transmute during twin-twin interaction is of great interest but not well understood.In this work,atomistic simulation is performed to investigate interaction between{1011}twin variants.Our results show that when an incoming twin variant impinges on the other which acts as a barrier,surprisingly,the barrier twin can grow at the expense of the incoming twin.Eventually one variant consumes the other.Structural analysis shows that the twinning dislocations of the barrier variant are able to penetrate the zone of twin-twin intersection,by plowing through the lattice of one variant and transform its lattice into the lattice of the other.Careful lattice correspondence analysis reveals that,the lattice transformation from one variant to the other is close to{1012}{1011}twinning,but the orientation relationship deviates by a minor lattice rotation.This deviation presents a significant energy barrier to the lattice transformation,and thus it is expected such a twin-twin interaction will increase the stress for twin growth. 展开更多
关键词 MAGNESIUM Contraction twinning Atomistic simulation Lattice transformation
在线阅读 下载PDF
IncEFL:a sharing incentive mechanism for edge-assisted federated learning in industrial IoT
14
作者 Jiewei Chen Shaoyong Guo +3 位作者 Tao Shen Yan Feng Jian Gao Xuesong Qiu 《Digital Communications and Networks》 2025年第1期106-115,共10页
As the information sensing and processing capabilities of IoT devices increase,a large amount of data is being generated at the edge of Industrial IoT(IIoT),which has become a strong foundation for distributed Artific... As the information sensing and processing capabilities of IoT devices increase,a large amount of data is being generated at the edge of Industrial IoT(IIoT),which has become a strong foundation for distributed Artificial Intelligence(AI)applications.However,most users are reluctant to disclose their data due to network bandwidth limitations,device energy consumption,and privacy requirements.To address this issue,this paper introduces an Edge-assisted Federated Learning(EFL)framework,along with an incentive mechanism for lightweight industrial data sharing.In order to reduce the information asymmetry between data owners and users,an EFL model-sharing incentive mechanism based on contract theory is designed.In addition,a weight dispersion evaluation scheme based on Wasserstein distance is proposed.This study models an optimization problem of node selection and sharing incentives to maximize the EFL model consumers'profit and ensure the quality of training services.An incentive-based EFL algorithm with individual rationality and incentive compatibility constraints is proposed.Finally,the experimental results verify the effectiveness of the proposed scheme in terms of positive incentives for contract design and performance analysis of EFL systems. 展开更多
关键词 Federated learning Data sharing Edge intelligence INCENTIVES Contract theory
在线阅读 下载PDF
Study on the Philosophical Implications of Faust
15
作者 FEI Yujie ZHOU Lei 《Sino-US English Teaching》 2025年第4期147-152,共6页
Faust,as a classic image in Western literature and philosophy,has been endowed with profound philosophical connotations in Johann Wolfgang von Goethe’s epic reconstruction.This article starts from Faust’s dual ident... Faust,as a classic image in Western literature and philosophy,has been endowed with profound philosophical connotations in Johann Wolfgang von Goethe’s epic reconstruction.This article starts from Faust’s dual identity as a“seeker”and a“paradoxical person”,revealing the dialectical unity of his philosophical meaning:In the dynamic process of“infinite pursuit”and“self denial”,Faust not only embodies humanity’s eternal questioning of the essence of existence,but also reflects the struggle and transcendence of human spirit in the dilemma of modernity.Through in-depth analysis of the five stages of Faust’s soul conflict and his contractual relationship with the devil,this article clarifies that Faust is not only a spiritual symbol of the Renaissance to the Age of Enlightenment,but also a mirror of modern society under the guidance of technological rationality. 展开更多
关键词 FAUST philosophical meaning soul conflict devil’s contract modernity
在线阅读 下载PDF
The Application of Blockchain Technology in the Financial Field
16
作者 Yanling Liu Yun Li 《Proceedings of Business and Economic Studies》 2025年第2期191-197,共7页
Blockchain technology,as a revolutionary tool,is profoundly changing the way the financial field works.Its application has expanded from digital currency to many fields,such as smart contracts,cross-border payments,tr... Blockchain technology,as a revolutionary tool,is profoundly changing the way the financial field works.Its application has expanded from digital currency to many fields,such as smart contracts,cross-border payments,trade finance,and digital identity management,providing important support for simplifying financial service processes,reducing costs,and improving efficiency.However,the widespread application of blockchain technology still faces challenges such as scalability,regulatory compliance,and cybersecurity,limiting its full integration in the financial industry.This study systematically reviews the status quo,development history,and future trends of blockchain technology application in the financial sector,analyzes its key role in capital markets,decentralized finance(DeFi),and other fields,and explores the potential of emerging solutions such as hybrid blockchain and dynamic regulatory frameworks. 展开更多
关键词 Blockchain Decentralized finance Smart contracts Cross-border payments
在线阅读 下载PDF
A verifiable EVM-based cross-language smart contract implementation scheme for matrix calculation
17
作者 Yunhua He Yigang Yang +4 位作者 Chao Wang Anke Xie Li Ma Bin Wu Yongdong Wu 《Digital Communications and Networks》 2025年第2期432-441,共10页
The wide application of smart contracts allows industry companies to implement some complex distributed collaborative businesses,which involve the calculation of complex functions,such as matrix operations.However,com... The wide application of smart contracts allows industry companies to implement some complex distributed collaborative businesses,which involve the calculation of complex functions,such as matrix operations.However,complex functions such as matrix operations are difficult to implement on Ethereum Virtual Machine(EVM)-based smart contract platforms due to their distributed security environment limitations.Existing off-chain methods often result in a significant reduction in contract execution efficiency,thus a platform software development kit interface implementation method has become a feasible way to reduce overheads,but this method cannot verify operation correctness and may leak sensitive user data.To solve the above problems,we propose a verifiable EVM-based smart contract cross-language implementation scheme for complex operations,especially matrix operations,which can guarantee operation correctness and user privacy while ensuring computational efficiency.In this scheme,a verifiable interaction process is designed to verify the computation process and results,and a matrix blinding technology is introduced to protect sensitive user data in the calculation process.The security analysis and performance tests show that the proposed scheme can satisfy the correctness and privacy of the cross-language implementation of smart contracts at a small additional efficiency cost. 展开更多
关键词 Smart contract Blockchain Cross-language programming Bilinear pairing Publicly verifiable computation
在线阅读 下载PDF
Smart Contract Vulnerability Detection Using Large Language Models and Graph Structural Analysis
18
作者 Ra-Yeon Choi Yeji Song +3 位作者 Minsoo Jang Taekyung Kim Jinhyun Ahn Dong-Hyuk Im 《Computers, Materials & Continua》 2025年第4期785-801,共17页
Smart contracts are self-executing programs on blockchains that manage complex business logic with transparency and integrity.However,their immutability after deployment makes programming errors particularly critical,... Smart contracts are self-executing programs on blockchains that manage complex business logic with transparency and integrity.However,their immutability after deployment makes programming errors particularly critical,as such errors can be exploited to compromise blockchain security.Existing vulnerability detection methods often rely on fixed rules or target specific vulnerabilities,limiting their scalability and adaptability to diverse smart contract scenarios.Furthermore,natural language processing approaches for source code analysis frequently fail to capture program flow,which is essential for identifying structural vulnerabilities.To address these limitations,we propose a novel model that integrates textual and structural information for smart contract vulnerability detection.Our approach employs the CodeBERT NLP model for textual analysis,augmented with structural insights derived from control flow graphs created using the abstract syntax tree and opcode of smart contracts.Each graph node is embedded using Sent2Vec,and centrality analysis is applied to highlight critical paths and nodes within the code.The extracted features are normalized and combined into a prompt for a large language model to detect vulnerabilities effectivel.Experimental results demonstrate the superiority of our model,achieving an accuracy of 86.70%,a recall of 84.87%,a precision of 85.24%,and an F1-score of 84.46%.These outcomes surpass existing methods,including CodeBERT alone(accuracy:81.26%,F1-score:79.84%)and CodeBERT combined with abstract syntax tree analysis(accuracy:83.48%,F1-score:79.65%).The findings underscore the effectiveness of incorporating graph structural information alongside text-based analysis,offering improved scalability and performance in detecting diverse vulnerabilities. 展开更多
关键词 Blockchain smart contract vulnerability detection large language model
在线阅读 下载PDF
Machine Learning on Blockchain (MLOB): A New Paradigm for Computational Security in Engineering
19
作者 Zhiming Dong Weisheng Lu 《Engineering》 2025年第4期250-263,共14页
Machine learning(ML)has been increasingly adopted to solve engineering problems with performance gauged by accuracy,efficiency,and security.Notably,blockchain technology(BT)has been added to ML when security is a part... Machine learning(ML)has been increasingly adopted to solve engineering problems with performance gauged by accuracy,efficiency,and security.Notably,blockchain technology(BT)has been added to ML when security is a particular concern.Nevertheless,there is a research gap that prevailing solutions focus primarily on data security using blockchain but ignore computational security,making the traditional ML process vulnerable to off-chain risks.Therefore,the research objective is to develop a novel ML on blockchain(MLOB)framework to ensure both the data and computational process security.The central tenet is to place them both on the blockchain,execute them as blockchain smart contracts,and protect the execution records on-chain.The framework is established by developing a prototype and further calibrated using a case study of industrial inspection.It is shown that the MLOB framework,compared with existing ML and BT isolated solutions,is superior in terms of security(successfully defending against corruption on six designed attack scenario),maintaining accuracy(0.01%difference with baseline),albeit with a slightly compromised efficiency(0.231 second latency increased).The key finding is MLOB can significantly enhances the computational security of engineering computing without increasing computing power demands.This finding can alleviate concerns regarding the computational resource requirements of ML-BT integration.With proper adaption,the MLOB framework can inform various novel solutions to achieve computational security in broader engineering challenges. 展开更多
关键词 Engineering computing Machine learning Blockchain Blockchain smart contract Deployable framework
在线阅读 下载PDF
A Hybrid Machine Learning and Blockchain Framework for IoT DDoS Mitigation
20
作者 Singamaneni Krishnapriya Sukhvinder Singh 《Computer Modeling in Engineering & Sciences》 2025年第8期1849-1881,共33页
The explosive expansion of the Internet of Things(IoT)systems has increased the imperative to have strong and robust solutions to cyber Security,especially to curtail Distributed Denial of Service(DDoS)attacks,which c... The explosive expansion of the Internet of Things(IoT)systems has increased the imperative to have strong and robust solutions to cyber Security,especially to curtail Distributed Denial of Service(DDoS)attacks,which can cripple critical infrastructure.The proposed framework presented in the current paper is a new hybrid scheme that induces deep learning-based traffic classification and blockchain-enabledmitigation tomake intelligent,decentralized,and real-time DDoS countermeasures in an IoT network.The proposed model fuses the extracted deep features with statistical features and trains them by using traditional machine-learning algorithms,which makes them more accurate in detection than statistical features alone,based on the Convolutional Neural Network(CNN)architecture,which can extract deep features.A permissioned blockchain will be included to record the threat cases immutably and automatically execute mitigation measures through smart contracts to provide transparency and resilience.When tested on two test sets,BoT-IoT and IoT-23,the framework obtains a maximum F1-score at 97.5 percent and only a 1.8 percent false positive rate,which compares favorably to other solutions regarding effectiveness and the amount of time required to respond.Our findings support the feasibility of our method as an extensible and secure paradigm of nextgeneration IoT security,which has constrictive utility in mission-critical or resource-constrained settings.The work is a substantial milestone in autonomous and trustful mitigation against DDoS attacks through intelligent learning and decentralized enforcement. 展开更多
关键词 IoT security DDoS mitigation machine learning CNN random forest blockchain smart contracts cyberattack detection
在线阅读 下载PDF
上一页 1 2 69 下一页 到第
使用帮助 返回顶部