We aimed at the release and dynamic management of CAD network graphics library (NGL). The characteristics of realization on network of CAD graphics are analysed, while the existing problems of the presenting share met...We aimed at the release and dynamic management of CAD network graphics library (NGL). The characteristics of realization on network of CAD graphics are analysed, while the existing problems of the presenting share methods of graphics file are also discussed. Release and dynamic management are accomplished with the B/S combined with C/S as well as the file organization based on attribute information, which have essential practical sense to the establishment of CAD NGL, share and cooperation in tech-design as well as the distance education of engineering graphics.展开更多
A novel visually meaningful image encryption algorithm is proposed based on a hyperchaotic system and compressive sensing(CS), which aims to improve the visual security of steganographic image and decrypted quality. F...A novel visually meaningful image encryption algorithm is proposed based on a hyperchaotic system and compressive sensing(CS), which aims to improve the visual security of steganographic image and decrypted quality. First, a dynamic spiral block scrambling is designed to encrypt the sparse matrix generated by performing discrete wavelet transform(DWT)on the plain image. Then, the encrypted image is compressed and quantified to obtain the noise-like cipher image. Then the cipher image is embedded into the alpha channel of the carrier image in portable network graphics(PNG) format to generate the visually meaningful steganographic image. In our scheme, the hyperchaotic Lorenz system controlled by the hash value of plain image is utilized to construct the scrambling matrix, the measurement matrix and the embedding matrix to achieve higher security. In addition, compared with other existing encryption algorithms, the proposed PNG-based embedding method can blindly extract the cipher image, thus effectively reducing the transmission cost and storage space. Finally, the experimental results indicate that the proposed encryption algorithm has very high visual security.展开更多
With the advancement of communication technology,a large number of data are constantly transmitted through the internet for various purposes,which are prone to be illegally accessed by third parties.Therefore,securing...With the advancement of communication technology,a large number of data are constantly transmitted through the internet for various purposes,which are prone to be illegally accessed by third parties.Therefore,securing such data is crucial to protect the transmitted information from falling into the wrong hands.Among data protection schemes,Secret Image Sharing is one of the most popular methods.It protects critical messages or data by embedding them in an image and sharing it with some users.Furthermore,it combines the security concepts in that private data are embedded into a cover image and then secured using the secret-sharing method.Despite its advantages,this method may produce noise,making the resulting stego file much different from its cover.Moreover,the size of private data that can be embedded is limited.This research works on these problems by utilizing prediction-error expansion and histogram-based approaches to embed the data.To recover the cover image,the SS method based on the Chinese remainder theorem is used.The experimental results indicate that this proposed method performs better than similar methods in several cover images and scenarios.展开更多
针对胶囊网络(CapsNet)在处理含有背景噪声信息的复杂图像时分类效果不佳且计算开销大的问题,提出一种基于注意力机制和权值共享的改进胶囊网络模型——共享转换矩阵胶囊网络(STM-CapsNet)。该模型主要包括以下改进:1)在特征提取层中引...针对胶囊网络(CapsNet)在处理含有背景噪声信息的复杂图像时分类效果不佳且计算开销大的问题,提出一种基于注意力机制和权值共享的改进胶囊网络模型——共享转换矩阵胶囊网络(STM-CapsNet)。该模型主要包括以下改进:1)在特征提取层中引入注意力模块,使低层胶囊能够聚焦于与分类任务相关的实体特征;2)将空间位置接近的低层胶囊分为若干组,每组内的低层胶囊通过共享转换矩阵映射到高层胶囊,降低计算开销,提高模型鲁棒性;3)在间隔损失与重构损失的基础上加入L2正则化项,防止模型过拟合。在CIFAR10、SVHN(Street View House Number)、FashionMNIST复杂图像数据集上的实验结果表明,各改进均能有效提升模型性能;当迭代次数为3,共享转换矩阵数为5时,STM-CapsNet模型的平均准确率分别为85.26%、93.17%、94.96%,平均参数量为8.29 MB,比基线模型的综合性能更优。展开更多
目的:分析国内影像归档和通信系统(picture archiving and communication systems,PACS)的应用现状及存在问题,为PACS未来的设计和发展提供技术支持和依据。方法:回顾2015年6月至2016年5月某院介入诊疗科PACS运行情况,结合全院实际情况...目的:分析国内影像归档和通信系统(picture archiving and communication systems,PACS)的应用现状及存在问题,为PACS未来的设计和发展提供技术支持和依据。方法:回顾2015年6月至2016年5月某院介入诊疗科PACS运行情况,结合全院实际情况系统分析国内PACS的应用现状及问题。结果:介入诊疗科PACS运行存在问题较多,影像采集设备使用时间跨度长达13 a,6.8%的工作站、14.2%的影像采集设备未接入PACS,4.1%的患者、2.9%的影像未传至PACS。结论:国内PACS设计要适合未来发展预期,运行要稳定、高效、安全、可靠,应用要满足未来医疗、科研、教学需求,为PACS在互联网医疗时代奠定坚实基础。展开更多
文摘We aimed at the release and dynamic management of CAD network graphics library (NGL). The characteristics of realization on network of CAD graphics are analysed, while the existing problems of the presenting share methods of graphics file are also discussed. Release and dynamic management are accomplished with the B/S combined with C/S as well as the file organization based on attribute information, which have essential practical sense to the establishment of CAD NGL, share and cooperation in tech-design as well as the distance education of engineering graphics.
基金supported by the National Natural Science Foundation of China (Grant No. 61672124)the Password Theory Project of the 13th Five-Year Plan National Cryptography Development Fund (Grant No. MMJJ20170203)+3 种基金Liaoning Province Science and Technology Innovation Leading Talents Program Project (Grant No. XLYC1802013)Key R&D Projects of Liaoning Province (Grant No. 2019020105JH2/103)Jinan City ‘20 Universities’ Funding Projects Introducing Innovation Team Program (Grant No. 2019GXRC031)Research Fund of Guangxi Key Lab of Multi-source Information Mining & Security (Grant No. MIMS20-M-02)。
文摘A novel visually meaningful image encryption algorithm is proposed based on a hyperchaotic system and compressive sensing(CS), which aims to improve the visual security of steganographic image and decrypted quality. First, a dynamic spiral block scrambling is designed to encrypt the sparse matrix generated by performing discrete wavelet transform(DWT)on the plain image. Then, the encrypted image is compressed and quantified to obtain the noise-like cipher image. Then the cipher image is embedded into the alpha channel of the carrier image in portable network graphics(PNG) format to generate the visually meaningful steganographic image. In our scheme, the hyperchaotic Lorenz system controlled by the hash value of plain image is utilized to construct the scrambling matrix, the measurement matrix and the embedding matrix to achieve higher security. In addition, compared with other existing encryption algorithms, the proposed PNG-based embedding method can blindly extract the cipher image, thus effectively reducing the transmission cost and storage space. Finally, the experimental results indicate that the proposed encryption algorithm has very high visual security.
基金This research was supported by the Ministry of Education,Culture,Research and Technology,The Republic of Indonesia,Institut Teknologi Sepuluh Nopember,and Universitas 17 Agustus 1945 Surabaya.
文摘With the advancement of communication technology,a large number of data are constantly transmitted through the internet for various purposes,which are prone to be illegally accessed by third parties.Therefore,securing such data is crucial to protect the transmitted information from falling into the wrong hands.Among data protection schemes,Secret Image Sharing is one of the most popular methods.It protects critical messages or data by embedding them in an image and sharing it with some users.Furthermore,it combines the security concepts in that private data are embedded into a cover image and then secured using the secret-sharing method.Despite its advantages,this method may produce noise,making the resulting stego file much different from its cover.Moreover,the size of private data that can be embedded is limited.This research works on these problems by utilizing prediction-error expansion and histogram-based approaches to embed the data.To recover the cover image,the SS method based on the Chinese remainder theorem is used.The experimental results indicate that this proposed method performs better than similar methods in several cover images and scenarios.
文摘针对胶囊网络(CapsNet)在处理含有背景噪声信息的复杂图像时分类效果不佳且计算开销大的问题,提出一种基于注意力机制和权值共享的改进胶囊网络模型——共享转换矩阵胶囊网络(STM-CapsNet)。该模型主要包括以下改进:1)在特征提取层中引入注意力模块,使低层胶囊能够聚焦于与分类任务相关的实体特征;2)将空间位置接近的低层胶囊分为若干组,每组内的低层胶囊通过共享转换矩阵映射到高层胶囊,降低计算开销,提高模型鲁棒性;3)在间隔损失与重构损失的基础上加入L2正则化项,防止模型过拟合。在CIFAR10、SVHN(Street View House Number)、FashionMNIST复杂图像数据集上的实验结果表明,各改进均能有效提升模型性能;当迭代次数为3,共享转换矩阵数为5时,STM-CapsNet模型的平均准确率分别为85.26%、93.17%、94.96%,平均参数量为8.29 MB,比基线模型的综合性能更优。
文摘目的:分析国内影像归档和通信系统(picture archiving and communication systems,PACS)的应用现状及存在问题,为PACS未来的设计和发展提供技术支持和依据。方法:回顾2015年6月至2016年5月某院介入诊疗科PACS运行情况,结合全院实际情况系统分析国内PACS的应用现状及问题。结果:介入诊疗科PACS运行存在问题较多,影像采集设备使用时间跨度长达13 a,6.8%的工作站、14.2%的影像采集设备未接入PACS,4.1%的患者、2.9%的影像未传至PACS。结论:国内PACS设计要适合未来发展预期,运行要稳定、高效、安全、可靠,应用要满足未来医疗、科研、教学需求,为PACS在互联网医疗时代奠定坚实基础。
