检索结果-内蒙古大学图书馆

An Improved Distributed Secondary Control Scheme in Islanded AC Microgrids

学校读者我要写书评

暂无评论

An Improved Distributed Secondary Control Scheme in Islanded...

IEEE Energy Conversion Congress and Exposition

作者： Jiahao Yu Fei Gao Shanshan Wei Junzhong Xu Dawei Liao Yutong Zhao Key Laboratory of Control of Power Transmission and Conversion Ministry of Education Shanghai Jiao Tong University Shanghai China

ISBN: (数字)9781728158266

ISBN: (纸本)9781728158273

Following the hierarchical control architecture, this paper investigates the diffusion algorithm based distributed secondary control in islanded AC microgrids. The principle of diffusion algorithm is introduced first and then diffusion algorithm-based distributed secondary control strategies are analyzed in details. Compared to the conventional consensus algorithm employed in the secondary control, it is shown that diffusion algorithm shows a faster convergence and a smaller deviation from the nominal value. A three-node islanded AC MG is simulated and the results confirm that the proposed diffusion-based secondary control outperforms consensus-based approach in terms of voltage/frequency restoration.

关键词： Voltage control Inverters Eigenvalues and eigenfunctions Power transmission Education consensus algorithm Topology

Vulnerability Assessment of Blockchain Using Confrontation Deduction

学校读者我要写书评

暂无评论

Vulnerability Assessment of Blockchain Using Confrontation D...

Chinese Automation Congress (CAC)

作者： Luyu Chen Jing He Xiaofeng Ma Wei Ye School of Electronics and Information Engineering Toingji University Shangha China Suzhou Tongji Blockchain Research Institute Suzhou China

ISBN: (纸本)9781665426480

blockchain technology is one of the strategic emerging information technologies. It integrates a variety of technologies such as cryptography, peer-to-peer network, consensus algorithm and smart contract, and has been gradually applied in various fields. The contradiction between the rapid development of blockchain industry and the incompleteness of evaluation system and technical means has become increasingly prominent. The vulnerability of blockchain system is an important part of blockchain evaluation system. It is of great significance for the development of blockchain technology and large-scale application to fully study the vulnerability of blockchain system and conduct quantitative evaluation or real-time monitoring. This paper systematically analyzes the vulnerability of blockchain, and puts forward the technical indicators to evaluate the vulnerability of blockchain. Based on the vulnerability technical index of blockchain consensus algorithm and industrial blockchain consensus algorithm PBFT, a consensus algorithm confrontation deduction model is designed, and the vulnerability index of blockchain system using PBFT is experimentally simulated and evaluated.

关键词： Fault tolerance Simulation Fault tolerant systems Smart contracts consensus algorithm Real-time systems Blockchains

Smart GuardianChain: A Solution Based on Blockchain Technology for Ensuring Security of E-Health Records in a Smart Environment

学校读者我要写书评

暂无评论

Smart GuardianChain: A Solution Based on Blockchain Technolo...

Smart Devices (ICSD), International Conference on

作者： Vinod Sharma Kailash Aseri Ranadeep Reddy Palle Atul Agrawal Karthikeya Tallapneni Sourabh Kumar Jain Jiwaji University Sunrise University University of Houston SDBCT Chandigarh University Jayoti Vidyapeeth Women’s University

ISBN: (数字)9798350394412

ISBN: (纸本)9798350394429

In the age of rapidly progressing technology, the healthcare sector is embracing the revolution of digital transformation through the widespread adoption of Electronic Health Records (EHRs). Nevertheless, the digital realm also presents notable challenges, particularly pertaining to the security and confidentiality of patients' delicate health data. This document introduces the innovative Smart GuardianChain, a blockchain-based distributed system crafted to tackle these pivotal concerns by establishing an infallible, decentralized, and impervious platform for the management and sharing of *** GuardianChain capitalizes on a robust consensus algorithm to ensure the integrity of EHRs, thus safeguarding the genuineness of medical records in an increasingly interconnected healthcare ecosystem. To guarantee that solely authorized entities have access to patient information, the system integrates an intricate mechanism for access control. Patients are bestowed with complete authority over their EHRs, enabling them to manage access permissions as they deem appropriate. Through extensive experimentation, our results demonstrate the scalability, efficiency, and effectiveness of the proposed system, which not only enhances security but also preserves patient privacy. By addressing the pressing privacy challenges that EHR systems face today, Smart GuardianChain stands poised to revolutionize the quality of healthcare services, fostering trust and confidence in the digital healthcare landscape.

关键词： Industries Data privacy Privacy Vegetation mapping Land surface Medical services consensus algorithm Radiometry Electronic medical records Remote sensing

Sequential and Simultaneous Distance-based Dimension Reduction

学校读者我要写书评

暂无评论

arXiv 2019年

作者： Ni, Yijin Yu, Chuanping Ko, Andy Huo, Xiaoming H. Milton Stewart School of Industrial and Systems Engineering Georgia Institute of Technology United States

This paper introduces a method called Sequential and Simultaneous Distance-based Dimension Reduction (S2D2R) that performs simultaneous dimension reduction for a pair of random vectors based on distance covariance (dCov). Compared with sufficient dimension reduction (SDR) and canonical correlation analysis (CCA)-based approaches, S2D2R is a model-free approach that does not impose dimensional or distributional restrictions on variables and is more sensitive to nonlinear relationships. Theoretically, we establish a non-asymptotic error bound to guarantee the performance of S2D2R. Numerically, S2D2R performs comparable to or better than other state-of-the-art algorithms and is computationally faster. All codes of our S2D2R method can be found on, including an R package named S2D2R. Copyright © 2019, The Authors. All rights reserved.

关键词： consensus algorithm

Ethereum for Secure Authentication of IoT using Pre-Shared Keys (PSKs)

学校读者我要写书评

暂无评论

Ethereum for Secure Authentication of IoT using Pre-Shared K...

International Conference on Wireless Networks and Mobile Communications (WINCOM)

作者： Mohammad El-Hajj Ahmad Fadlallah Maroun Chamoun Ahmed Serhrouchni Saint Joseph University Lebanon University of Sciences and Arts in Lebanon Telecom ParisTech France

Enterprises are no doubt interested in reaching data collected from billions of Internet of Things (IoT) devices which opens a huge potential business. The main concern remains the security challenges from the distribution of key while using public key cryptography. To ensure that IOT connected devices can be trusted to be what they are supposed to be, robust IoT device authentication is mandated. Each IoT device therefore requires a unique identity which can be verified when the device tries to link to an intermediate device. One of the early solutions used to secure data transmission among parties in public networks is the Public Key Infrastructure (PKI) which is used to distribute and manage public keys (digital certificates) among different parties and these certificates are generated upon request by Certificate Authorities (CA). Nevertheless, for billions of devices connected to IoT and mobile phones, the distribution management of certificates for each client proved to be inefficient. In this research, we propose a decentralized authentication platform based on PKI and Ethereum Blockchain. The public key certificates are stored in a decentralized fashion and the private keys are stored inside the devices themselves. It also includes a protocol for Pre-Shared Keys (PSK) distribution. PSK keys are then used by PSK-based security protocols for securing the communication channel between two devices. This platform includes a client-side module, a server-side Wallet Management Function, and a smart contract deployed on the Ethereum Blockchain network. This platform can be used by applications for end devices and/or intermediate devices authentication and a secure Machine-to-Machine (M2M) communication. The proposed platform is validated by the implementation of a Secure Session Establishment between IoT devices. Results show that the solution implementation has minimal impact on the existing networks, and the secure session setup time between two devices is negligib

关键词： Blockchain consensus algorithm Authentication Public key Smart contracts

ComChain: Bridging the Gap Between Public and Consortium Blockchains

学校读者我要写书评

暂无评论

ComChain: Bridging the Gap Between Public and Consortium Blo...

IEEE/ACM Int'l Conference on & Int'l Conference on Cyber, Physical and Social Computing (CPSCom) Green Computing and Communications (GreenCom)

作者： Guillaume Vizier Vincent Gramoli École Polytechnique University of Sydney

As an alternative to the energy greedy proof-of-work, new blockchains constrain the set of participants whose selection is debatable. These blockchains typically allow a fixed consortium of machines to decide upon new transaction blocks. In this paper, we introduce the community blockchain that bridges the gap between these public blockchains and constrained blockchains. The idea is to allow potentially all participants to decide upon “some” block while restricting the set of participants deciding upon “one” block. We also propose an implementation called ComChain that builds upon the Red Belly Blockchain, the fastest blockchain we are aware of. It runs a consensus among the existing community to elect a new community. This reconfiguration speeds up as the number of removed nodes increases.

关键词： Blockchain Peer-to-peer computing consensus algorithm Bridges Public key Reliability Data integrity

Prophet Inequality from Samples: Is the More the Merrier?

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Ezra, Tomer Harvard University Cambridge United States

We study a variant of the single-choice prophet inequality problem where the decision-maker does not know the underlying distribution and has only access to a set of samples from the distributions. Rubinstein et al. [2020] showed that the optimal competitive-ratio of ½ can surprisingly be obtained by observing a set of n samples, one from each of the distributions. In this paper, we prove that this competitive-ratio of ½becomes unattainable when the decision-maker is provided with a set of more samples. We then examine the natural class of ordinal static threshold algorithms, where the algorithm selects the i-th highest ranked sample, sets this sample as a static threshold, and then chooses the first value that exceeds this threshold. We show that the best possible algorithm within this class achieves a competitive-ratio of 0.433. Along the way, we utilize the tools developed in the paper and provide an alternative proof of the main result of Rubinstein et al. [2020]. Copyright © 2024, The Authors. All rights reserved.

关键词： consensus algorithm

Generalised Buchberger and Schreyer algorithms for strongly discrete coherent rings

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Lombardi, Henri Neuwirth, Stefan Yengui, Ihsen Université de Franche-Comté CNRS UMR 6623 LmB Besançon25000 France Département de mathématiques Faculté des sciences Université de Sfax Sfax3000 Tunisia

Let M be a finitely generated submodule of a free module over a multivariate polynomial ring with coefficients in a discrete coherent ring. We prove that its module MLT(M) of leading terms is countably generated and provide an algorithm for computing explicitly a generating set. This result is also useful when MLT(M) is not finitely generated. Suppose that the base ring is strongly discrete coherent. We provide a Buchberger-like algorithm and prove that it converges if, and only if, the module of leading terms is finitely generated. We also provide a constructive version of Hilbert's syzygy theorem by following Schreyer's method. Copyright © 2024, The Authors. All rights reserved.

关键词： consensus algorithm

MINI-BATCH KERNEL k-MEANS

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Jourdan, Ben Schwartzman, Gregory University of Edinburgh United Kingdom Japan

We present the first mini-batch kernel k-means algorithm, offering an order of magnitude improvement in running time compared to the full batch algorithm. A single iteration of our algorithm takes O͠(kb2) time, significantly faster than the O(n2) time required by the full batch kernel k-means, where n is the dataset size and b is the batch size. Extensive experiments demonstrate that our algorithm consistently achieves a 10-100x speedup with minimal loss in quality, addressing the slow runtime that has limited kernel k-means adoption in practice. We further complement these results with a theoretical analysis under an early stopping condition, proving that with a batch size of Ω͠ (max ｛γ4, γ2｝ · ϵ−2), the algorithm terminates in O(γ2/ϵ) iterations with high probability, where γ bounds the norm of points in feature space and ϵ is a termination threshold. Our analysis holds for any reasonable center initialization, and when using k-means++ initialization, the algorithm achieves an approximation ratio of O(log k) in expectation. For normalized kernels, such as Gaussian or Laplacian it holds that γ = 1. Taking ϵ = O(1) and b = Θ(log n), the algorithm terminates in O(1) iterations, with each iteration running in O͠(k) time. © 2024, CC BY.

关键词： consensus algorithm