With the widespread use of machine learning(ML)technology,the operational efficiency and responsiveness of power grids have been significantly enhanced,allowing smart grids to achieve high levels of automation and int...With the widespread use of machine learning(ML)technology,the operational efficiency and responsiveness of power grids have been significantly enhanced,allowing smart grids to achieve high levels of automation and intelligence.However,tree ensemble models commonly used in smart grids are vulnerable to adversarial attacks,making it urgent to enhance their robustness.To address this,we propose a robustness enhancement method that incorporates physical constraints into the node-splitting decisions of tree ensembles.Our algorithm improves robustness by developing a dataset of adversarial examples that comply with physical laws,ensuring training data accurately reflects possible attack scenarios while adhering to physical rules.In our experiments,the proposed method increased robustness against adversarial attacks by 100%when applied to real grid data under physical constraints.These results highlight the advantages of our method in maintaining efficient and secure operation of smart grids under adversarial conditions.展开更多
A machine learning based speech enhancement method is proposed to improve the intelligibility of whispered speech. A binary mask estimated by a two-class support vector machine （SVM） classifier is used to synthesize...A machine learning based speech enhancement method is proposed to improve the intelligibility of whispered speech. A binary mask estimated by a two-class support vector machine （SVM） classifier is used to synthesize the enhanced whisper. A novel noise robust feature called Gammatone feature cosine coefficients （GFCCs） extracted by an auditory periphery model is derived and used for the binary mask estimation. The intelligibility performance of the proposed method is evaluated and compared with the traditional speech enhancement methods. Objective and subjective evaluation results indicate that the proposed method can effectively improve the intelligibility of whispered speech which is contaminated by noise. Compared with the power subtract algorithm and the log-MMSE algorithm, both of which do not improve the intelligibility in lower signal-to-noise ratio （SNR） environments, the proposed method has good performance in improving the intelligibility of noisy whisper. Additionally, the intelligibility of the enhanced whispered speech using the proposed method also outperforms that of the corresponding unprocessed noisy whispered speech.展开更多
预测进阀温度的变化趋势对阀冷系统的运行状态有重要参考价值.针对传统方法存在数据收集时间跨度大和传感器存在误差等问题,本文提出了一种基于对抗扰动和局部信息增强的进阀温度预测模型Robust-InTemp.具体来说,Robust-InTemp通过对原...预测进阀温度的变化趋势对阀冷系统的运行状态有重要参考价值.针对传统方法存在数据收集时间跨度大和传感器存在误差等问题,本文提出了一种基于对抗扰动和局部信息增强的进阀温度预测模型Robust-InTemp.具体来说,Robust-InTemp通过对原始数据添加基于规则的高斯噪声,并使用基于梯度的对抗训练方法(projected gradient descent,PGD),增强了模型的泛化能力和抵抗噪声干扰的鲁棒性.同时,引入相对位置编码、一维卷积以及门控线性单元(gated linear unit,GLU),以增强模型对局部特征的学习能力,从而提高预测准确性.实验结果表明,与多种基准模型相比,Robust-InTemp在预测性能和抗干扰能力方面均有明显优势,进一步的消融实验也验证了模型中各个组件的有效性.展开更多
As one of the most popular digital image manipulations,contrast enhancement(CE)is frequently applied to improve the visual quality of the forged images and conceal traces of forgery,therefore it can provide evidence o...As one of the most popular digital image manipulations,contrast enhancement(CE)is frequently applied to improve the visual quality of the forged images and conceal traces of forgery,therefore it can provide evidence of tampering when verifying the authenticity of digital images.Contrast enhancement forensics techniques have always drawn significant attention for image forensics community,although most approaches have obtained effective detection results,existing CE forensic methods exhibit poor performance when detecting enhanced images stored in the JPEG format.The detection of forgery on contrast adjustments in the presence of JPEG post processing is still a challenging task.In this paper,we propose a new CE forensic method based on convolutional neural network(CNN),which is robust to JPEG compression.The proposed network relies on a Xception-based CNN with two preprocessing strategies.Firstly,unlike the conventional CNNs which accepts the original image as its input,we feed the CNN with the gray-level co-occurrence matrix(GLCM)of image which contains CE fingerprints,then the constrained convolutional layer is used to extract high-frequency details in GLCMs under JPEG compression,finally the output of the constrained convolutional layer becomes the input of Xception to extract multiple features for further classification.Experimental results show that the proposed detector achieves the best performance for CE forensics under JPEG post-processing compared with the existing methods.展开更多
Different devices in the recent era generated a vast amount of digital video.Generally,it has been seen in recent years that people are forging the video to use it as proof of evidence in the court of justice.Many kin...Different devices in the recent era generated a vast amount of digital video.Generally,it has been seen in recent years that people are forging the video to use it as proof of evidence in the court of justice.Many kinds of researches on forensic detection have been presented,and it provides less accuracy.This paper proposed a novel forgery detection technique in image frames of the videos using enhanced Convolutional Neural Network(CNN).In the initial stage,the input video is taken as of the dataset and then converts the videos into image frames.Next,perform pre-sampling using the Adaptive Rood Pattern Search(ARPS)algorithm intended for reducing the useless frames.In the next stage,perform preprocessing for enhancing the image frames.Then,face detection is done as of the image utilizing the Viola-Jones algorithm.Finally,the improved Crow Search Algorithm(ICSA)has been used to select the extorted features and inputted to the Enhanced Convolutional Neural Network(ECNN)classifier for detecting the forged image frames.The experimental outcome of the proposed system has achieved 97.21%accuracy compared to other existing methods.展开更多
日益频繁的极端天气给电热耦合系统造成的影响愈发严重。韧性是衡量系统抵御极端事件、减少故障影响并快速恢复的核心指标。为提升电热耦合系统抵御极端灾害的能力,提出一种考虑热惯性的热电联产虚拟电厂(combined heat and power-virtu...日益频繁的极端天气给电热耦合系统造成的影响愈发严重。韧性是衡量系统抵御极端事件、减少故障影响并快速恢复的核心指标。为提升电热耦合系统抵御极端灾害的能力,提出一种考虑热惯性的热电联产虚拟电厂(combined heat and power-virtual power plant,CHP-VPP)两阶段三层韧性提升策略。第一阶段以联络开关成本最小为目标,基于最小生成树理论对系统进行重构;第二阶段以运行成本最小为目标,基于分布鲁棒优化理论制定最恶劣的故障场景下的最优决策。采用列与约束生成算法进行迭代求解。基于IEEE 33节点电力系统+6节点供热系统构建CHP-VPP测试系统,仿真结果表明,所提出的方法可有效提升CHP-VPP应对极端灾害的韧性。展开更多
基金This work was supported by Natural Science Foundation of China(Nos.62303126,62362008,62066006,authors Zhenyong Zhang and Bin Hu,https://www.nsfc.gov.cn/,accessed on 25 July 2024)Guizhou Provincial Science and Technology Projects(No.ZK[2022]149,author Zhenyong Zhang,https://kjt.guizhou.gov.cn/,accessed on 25 July 2024)+1 种基金Guizhou Provincial Research Project(Youth)forUniversities(No.[2022]104,author Zhenyong Zhang,https://jyt.guizhou.gov.cn/,accessed on 25 July 2024)GZU Cultivation Project of NSFC(No.[2020]80,author Zhenyong Zhang,https://www.gzu.edu.cn/,accessed on 25 July 2024).
文摘With the widespread use of machine learning(ML)technology,the operational efficiency and responsiveness of power grids have been significantly enhanced,allowing smart grids to achieve high levels of automation and intelligence.However,tree ensemble models commonly used in smart grids are vulnerable to adversarial attacks,making it urgent to enhance their robustness.To address this,we propose a robustness enhancement method that incorporates physical constraints into the node-splitting decisions of tree ensembles.Our algorithm improves robustness by developing a dataset of adversarial examples that comply with physical laws,ensuring training data accurately reflects possible attack scenarios while adhering to physical rules.In our experiments,the proposed method increased robustness against adversarial attacks by 100%when applied to real grid data under physical constraints.These results highlight the advantages of our method in maintaining efficient and secure operation of smart grids under adversarial conditions.
基金The National Natural Science Foundation of China (No.61231002,61273266,51075068,60872073,60975017, 61003131)the Ph.D.Programs Foundation of the Ministry of Education of China(No.20110092130004)+1 种基金the Science Foundation for Young Talents in the Educational Committee of Anhui Province(No. 2010SQRL018)the 211 Project of Anhui University(No.2009QN027B)
文摘A machine learning based speech enhancement method is proposed to improve the intelligibility of whispered speech. A binary mask estimated by a two-class support vector machine （SVM） classifier is used to synthesize the enhanced whisper. A novel noise robust feature called Gammatone feature cosine coefficients （GFCCs） extracted by an auditory periphery model is derived and used for the binary mask estimation. The intelligibility performance of the proposed method is evaluated and compared with the traditional speech enhancement methods. Objective and subjective evaluation results indicate that the proposed method can effectively improve the intelligibility of whispered speech which is contaminated by noise. Compared with the power subtract algorithm and the log-MMSE algorithm, both of which do not improve the intelligibility in lower signal-to-noise ratio （SNR） environments, the proposed method has good performance in improving the intelligibility of noisy whisper. Additionally, the intelligibility of the enhanced whispered speech using the proposed method also outperforms that of the corresponding unprocessed noisy whispered speech.
文摘预测进阀温度的变化趋势对阀冷系统的运行状态有重要参考价值.针对传统方法存在数据收集时间跨度大和传感器存在误差等问题,本文提出了一种基于对抗扰动和局部信息增强的进阀温度预测模型Robust-InTemp.具体来说,Robust-InTemp通过对原始数据添加基于规则的高斯噪声,并使用基于梯度的对抗训练方法(projected gradient descent,PGD),增强了模型的泛化能力和抵抗噪声干扰的鲁棒性.同时,引入相对位置编码、一维卷积以及门控线性单元(gated linear unit,GLU),以增强模型对局部特征的学习能力,从而提高预测准确性.实验结果表明,与多种基准模型相比,Robust-InTemp在预测性能和抗干扰能力方面均有明显优势,进一步的消融实验也验证了模型中各个组件的有效性.
基金This work was supported in part by the National Key Research and Development of China(2018YFC0807306)National NSF of China(U1936212,61672090)Beijing Fund-Municipal Education Commission Joint Project(KZ202010015023).
文摘As one of the most popular digital image manipulations,contrast enhancement(CE)is frequently applied to improve the visual quality of the forged images and conceal traces of forgery,therefore it can provide evidence of tampering when verifying the authenticity of digital images.Contrast enhancement forensics techniques have always drawn significant attention for image forensics community,although most approaches have obtained effective detection results,existing CE forensic methods exhibit poor performance when detecting enhanced images stored in the JPEG format.The detection of forgery on contrast adjustments in the presence of JPEG post processing is still a challenging task.In this paper,we propose a new CE forensic method based on convolutional neural network(CNN),which is robust to JPEG compression.The proposed network relies on a Xception-based CNN with two preprocessing strategies.Firstly,unlike the conventional CNNs which accepts the original image as its input,we feed the CNN with the gray-level co-occurrence matrix(GLCM)of image which contains CE fingerprints,then the constrained convolutional layer is used to extract high-frequency details in GLCMs under JPEG compression,finally the output of the constrained convolutional layer becomes the input of Xception to extract multiple features for further classification.Experimental results show that the proposed detector achieves the best performance for CE forensics under JPEG post-processing compared with the existing methods.
文摘Different devices in the recent era generated a vast amount of digital video.Generally,it has been seen in recent years that people are forging the video to use it as proof of evidence in the court of justice.Many kinds of researches on forensic detection have been presented,and it provides less accuracy.This paper proposed a novel forgery detection technique in image frames of the videos using enhanced Convolutional Neural Network(CNN).In the initial stage,the input video is taken as of the dataset and then converts the videos into image frames.Next,perform pre-sampling using the Adaptive Rood Pattern Search(ARPS)algorithm intended for reducing the useless frames.In the next stage,perform preprocessing for enhancing the image frames.Then,face detection is done as of the image utilizing the Viola-Jones algorithm.Finally,the improved Crow Search Algorithm(ICSA)has been used to select the extorted features and inputted to the Enhanced Convolutional Neural Network(ECNN)classifier for detecting the forged image frames.The experimental outcome of the proposed system has achieved 97.21%accuracy compared to other existing methods.
文摘日益频繁的极端天气给电热耦合系统造成的影响愈发严重。韧性是衡量系统抵御极端事件、减少故障影响并快速恢复的核心指标。为提升电热耦合系统抵御极端灾害的能力,提出一种考虑热惯性的热电联产虚拟电厂(combined heat and power-virtual power plant,CHP-VPP)两阶段三层韧性提升策略。第一阶段以联络开关成本最小为目标,基于最小生成树理论对系统进行重构;第二阶段以运行成本最小为目标,基于分布鲁棒优化理论制定最恶劣的故障场景下的最优决策。采用列与约束生成算法进行迭代求解。基于IEEE 33节点电力系统+6节点供热系统构建CHP-VPP测试系统,仿真结果表明,所提出的方法可有效提升CHP-VPP应对极端灾害的韧性。
