An Efficient and Secure Multi-Secret Sharing Scheme with General Access Structures

A multiple secret sharing scheme can share a group of secrets in each sharing session, which is very useful especially in sharing large secrets. However, most of the existing multiple secret sharing schemes are （t, n） threshold schemes, so they are fit for only threshold applications and unfit for the applications of general access structures. Due to the fact that a （t, n） threshold scheme could only handle a small fraction of the secret sharing idea, a novel multi-secret sharing scheme is proposed, which is designed based on general access structures. The security of this scheme is the same as that of Shamir＇s threshold secret sharing scheme. Compared with the existing multiple secret sharing schemes, the proposed scheme can provide greater capabilities for many applications because it is able to deal with applications of general access structures.

A Summary of the Large-Scale Access Convergence Network Structure

Under the requirement of everything over IP, network service shows the following characteristics:(1) network service increases its richness;(2) broadband streaming media becomes the mainstream. To achieve unified multi-service bearing in the IP network, the largescale access convergence network architecture is proposed. This flat access convergence structure with ultra-small hops, which shortens the service transmission path, reduces the complexity of the edge of the network, and achieves IP strong waist model with the integration of computation, storage and transmission. The key technologies are also introduced in this paper, including endto-end performance guarantee for real time interactive services, fog storing mechanism, and built-in safety transmission with integration of aggregation and control.

Design and Implementation of Memory Access Fast Switching Structure in Cluster-Based Reconfigurable Array Processor

Memory access fast switching structures in cluster are studied,and three kinds of fast switching structures（ FS,LR2 SS,and LAPS） are proposed. A mixed simulation test bench is constructed and used for statistic of data access delay among these three structures in various cases. Finally these structures are realized on Xilinx FPGA development board and DCT,FFT,SAD,IME,FME,and de-blocking filtering algorithms are mapped onto the structures. Compared with available architectures,our proposed structures have lower data access delay and lower area.

A Group Oriented Cryptosystem for the Vector Space Access Structure

A group oriented cryptosystem for the vector space access structure was proposed. This cryptosystem adopts self-certified public keys. It allows the participants of an authorized subset to cooperatively access an encrypted message. All data delivered in the cryptosystem are public. Therefore it does not need a partial decrypting results combiner and any secure communication channel. The security of the group oriented cryptosystem is based on the intractability of the discrete log problem and difficulty of factoring large integers. The suspected attacks can not break it.

Study of the impacts of upstream natural gas market reform in China on infrastructure deployment and social welfare using an SVM-based rolling horizon stochastic game analysis

Natural gas is expected to play a much more important role in China in future decades, and market reform is crucial for its rapid market penetration. At present, the main gas fields, pipelines and liquefied natural gas(LNG) infrastructure are mainly monopolized by large state-owned companies, and one of the important market reform policies is to open up LNG import rights to smaller private companies and traders. Therefore, in the present study, a game theoretical model is proposed to analyze and compare the impacts of different market structures on infrastructure deployment and social welfare. Moreover, a support vector machine-based rolling horizon stochastic method is adopted in the model to simulate real LNG price fluctuations. Four market reform scenarios are proposed considering different policies such as business separation, third-party access(TPA) and their combinations. The results indicate that, with third-party access(TPA)entrance into the LNG market, the construction of LNG infrastructure will be promoted and more gas will be provided at lower prices, and thus the total social welfare will be improved greatly.

Mem Brain: An Easy-to-Use Online Webserver for Transmembrane Protein Structure Prediction

Membrane proteins are an important kind of proteins embedded in the membranes of cells and play crucial roles in living organisms, such as ion channels,transporters, receptors. Because it is difficult to determinate the membrane protein's structure by wet-lab experiments,accurate and fast amino acid sequence-based computational methods are highly desired. In this paper, we report an online prediction tool called Mem Brain, whose input is the amino acid sequence. Mem Brain consists of specialized modules for predicting transmembrane helices, residue–residue contacts and relative accessible surface area of a-helical membrane proteins. Mem Brain achieves aprediction accuracy of 97.9% of ATMH, 87.1% of AP,3.2 ± 3.0 of N-score, 3.1 ± 2.8 of C-score. Mem BrainContact obtains 62%/64.1% prediction accuracy on training and independent dataset on top L/5 contact prediction,respectively. And Mem Brain-Rasa achieves Pearson correlation coefficient of 0.733 and its mean absolute error of13.593. These prediction results provide valuable hints for revealing the structure and function of membrane proteins.Mem Brain web server is free for academic use and available at www.csbio.sjtu.edu.cn/bioinf/Mem Brain/.

Analysis of the Spatial Structure of Tourism Resources in Ji'an City

This paper analyzed characteristics of tourism resources in Ji'an City,and carried out quantitative analysis of local tourism resources based on agglomeration effect of resources,connectivity analysis,and accessibility analysis. The results showed that the city has poor loop of tourism network,major scenic areas(spots) have moderate network accessibility,in view of this,suggestions for the optimum development of local tourism industry were proposed.

Examples for Application of Gravitational Model in the Investigation of Spatial Structure

In this paper the authors wish to introduce an application of the gravitational model through two concrete examples. In their investigation the gravitational model was transformed to analyze the spatial structure of Europe, and the impact of accessibility in Hungary. In this analysis not only the size of gravitational forces but their direction can also be measured. Displacements were illustrated by a bi-dimensional regression, which gives a new perspective to the investigation of spatial structure.

Tunable Super-Structured Fiber Bragg Gratings with Perfect Sequences Based on m-Sequence

Recently, a tunable fiber Bragg grating(FBG) was developed by using stress-responsive colloidal crystals. In this paper, we have simulated the application of these nanoparticles into the super-structured fiber Bragg grating(SSFBG) written with perfect sequences derived from a short maximal-length sequence. A tunable SSFBG will be available to overcome the prohibitive temperature variation of the optical codecs. Nevertheless,we presented a method to implement coherent time spreading optical code-division multiple-access(OCDMA) where a unique code(or perfect sequence) can be reused and mixed with different wavelengths to obtain a tunable wavelength-division multiplexing(WDM)system. In order to maximize the binary throughput, we have selected a unique short maximal-length sequence composed of 7 chips that can be tuned with 7 different optical wavelengths. We found thousands of different tunable combinations that presented power contrast ratios(P/C) higher than 12 dB. When a WDM-OCDMA system used 2 different combinations simultaneously, the perfect binary detection with error correction codes was achieved successfully. The tunable SSFBG with colloidal crystals will be a simple and good alternative choice for fiber-to-the-home(FTTH) communications.

经桡动脉入路在神经介入手术中应用的思考

经桡动脉入路在神经介入治疗领域越来越受到重视,其具有并发症少,满意度高等优点,但存在学习曲线长、受到桡动脉及上肩部解剖因素限制、专用器械缺乏等缺点及难点。经桡动脉入路很少存在绝对禁忌证,远端及左侧桡动脉入路也逐渐作为入路选择,而通过无鞘经桡动脉入路或更大内腔的桡动脉鞘及器材组合,可以更广泛地开展各种神经介入手术。但在目前缺乏高级别证据的背景下,经桡动脉入路在颅内动脉瘤、颈动脉支架、机械取栓等神经介入治疗场景中仍存在一定困难及挑战,应用时更应权衡利弊。

药品标签信息无障碍化的分析框架与问题发现

2023年实施的《中华人民共和国无障碍环境建设法》,标志着中国的“无障碍改造”由面向残疾人和老年人向全人群“需要者”延伸,其中药品标签无障碍改造的规定即关涉全人群的用药安全。随机抽样选取100种日常家用药品,从药品标签的信息结构、语篇形式、符号模态3个角度考察、分析,发现在国家有关法规的不断推动下,中国药品标签的信息无障碍已普遍达到一定的水准,不过依然存在一系列问题有待改进:在信息结构上,需进一步突显“警示语”;在语篇结构上,应贯彻“消费者视角”的“重要性领先”原则,将适应症/功能主治、用法用量等最终消费者认为的最重要信息置于显著位置;在符号模态上,应进一步强化盲文意识和英文意识,更需要改善涉时间信息的无色钢印形式,以免给多数消费者造成识别障碍。由此,本文为语言学介入社会语言生活探索出一个基于言语行为的分析框架,即“信息结构的要素分布+语篇结构的排列方式+符号模态的形貌修辞”。

预防与控制:能源市场准入制度因应“双碳”目标的法律机理

能源结构低碳化转型作为“双碳”目标推进的重要战略,需要一系列制度措施来促进“清洁用能”和“能源供给”兼备的能源结构格局之形成。市场机制是能源结构低碳化转型的主要驱动,而能源市场准入制度是发挥市场机制秩序稳定与风险防范作用的重要约束和规制工具。因此,能源结构低碳化转型须构建完善的能源市场准入制度予以落实。传统能源市场准入制度对低碳治理的规制存在局限,革新的能源市场准入制度应当体现出维护能源市场秩序与气候公共利益实现的双重价值追求,功能定位在“预防—控制”的二元结构。“预防—控制”的功能定位呼唤能源市场准入制度明确更为科学的立法导向,该制度的规范建构须分别在“碳源”阶段与“碳流”阶段实施不同的功能分配、资源整合与立法策略:前者聚焦于调适能源开发利用中传统化石能源、清洁能源与可再生能源的比例,促进能源结构的低碳升级;后者注重能源产业的资质准入与行为监督,在保障能源合理供给的基础上强化低碳治理。由此切入,能源市场准入制度的革新应当按照统一性与差异性相结合的原则,从能源供给与低碳控制两个层面归纳所涉制度要素并对之定性,进一步完善准入标准、许可事务、准入审批与后续监管等要素的规范形态,充实规范内容与程序结构,提升制度能力。具言之,一是以协调能源供给与低碳控制为原则,注重不同能源准入情景下需要何种强度的资格准入、规模准入、项目审查等标准的实践性指向,形成具备稳定性与定量性的准入标准;二是以“能源供给的必要性”和“碳风险程度”为划分标准,根据不同能源开采企业与加工转换企业的特性来识别差异化的运营需求与行为要求,进而厘定各类能源产业的许可条件设定与事务分配;三是以准入审批与后续监管并重的结构化联结为理念,构建以“准入事务与标准的履行能力”为中心的专项审查模式与以“能源供给与低碳控制的义务履行实效”为中心的后续监管模式,强化被准入主体的能源服务供给与低碳义务的履行。

基于结构-过程-结果模型的医用耗材准入管理及效果分析

目的 评价结构-过程-结果模型在医院医用耗材准入管理中的应用与效果。方法 基于结构-过程-效果模型构建医院医用耗材准入管理体系,选取北京大学第一医院2020年7月—2022年12月准入的医用耗材作为研究对象,从组织结构、过程管理、结果评价三个维度对耗材准入通过率、耗占比、不良事件发生率、医疗纠纷发生率进行结果评价。结果 医用耗材准入管理体系实施后,耗材准入通过率提高(p<0.05);部分科室耗占比明显下降(p<0.05);不良事件发生率下降、未发生因耗材引发的医疗纠纷。结论 结构-过程-效果模型在医用耗材准入管理中取得明显效果,初步实现了耗材准入管理的科学性、规范性、有效性。

基于身份的跨域分层访问控制加密方案

访问控制加密强制执行读写权限,它通过一个既不知道明文、发送者和接收者,也不知道访问控制策略的净化器,阻断所有不被允许的阈下信道.针对访问控制加密中密钥生成中心所面临的繁重的密钥管理负担,本文提出了基于身份的跨域分层访问控制加密方案.首先,在基于身份的分层广播加密方案的基础上提出了与聚合器兼容的净化的基于身份的分层广播加密方案,进一步结合结构保持签名、非交互式零知识证明和聚合器提出了一个跨域分层访问控制加密的通用构造.然后证明了通用构造的安全性,即满足无读和无写规则.此外,对通用构造进行了实例化,实现了半静态安全并且密文大小是恒定的.最后对实例化方案进行了性能分析,结果表明本方案在保证效率的同时实现了更加丰富的功能.

基于“入径结构”的城市街区形态测度方法

为了加强物质形态与行为活动的关联性分析,本文基于街道、场地和建筑三种形态要素之间的拓扑连接关系,提出量化表述城市街区形态特征的“入径结构”方法。建立了街区基本结构以及互锁、并合、套叠三种复杂结构类型的认知理念,基于图论工具提出复杂性指标体系及其计算方法。以南京为例,通过分析高楼门街区的内部构成逻辑,以及不同时期的三个城市中心区的街区类型特征,验证了该方法在两个尺度上的实用性与有效性。为认知城市街区形态结构的内在组织逻辑提供了一种科学的测量方法,也为城市设计在微观层面的精细化和数字化发展建立了技术基础。

Reversible Data Hiding Algorithm in Encrypted Images Based on Adaptive Median Edge Detection and Ciphertext-Policy Attribute-Based Encryption

With the rapid advancement of cloud computing technology,reversible data hiding algorithms in encrypted images(RDH-EI)have developed into an important field of study concentrated on safeguarding privacy in distributed cloud environments.However,existing algorithms often suffer from low embedding capacities and are inadequate for complex data access scenarios.To address these challenges,this paper proposes a novel reversible data hiding algorithm in encrypted images based on adaptive median edge detection(AMED)and ciphertext-policy attributebased encryption(CP-ABE).This proposed algorithm enhances the conventional median edge detection(MED)by incorporating dynamic variables to improve pixel prediction accuracy.The carrier image is subsequently reconstructed using the Huffman coding technique.Encrypted image generation is then achieved by encrypting the image based on system user attributes and data access rights,with the hierarchical embedding of the group’s secret data seamlessly integrated during the encryption process using the CP-ABE scheme.Ultimately,the encrypted image is transmitted to the data hider,enabling independent embedding of the secret data and resulting in the creation of the marked encrypted image.This approach allows only the receiver to extract the authorized group’s secret data,thereby enabling fine-grained,controlled access.Test results indicate that,in contrast to current algorithms,the method introduced here considerably improves the embedding rate while preserving lossless image recovery.Specifically,the average maximum embedding rates for the(3,4)-threshold and(6,6)-threshold schemes reach 5.7853 bits per pixel(bpp)and 7.7781 bpp,respectively,across the BOSSbase,BOW-2,and USD databases.Furthermore,the algorithm facilitates permission-granting and joint-decryption capabilities.Additionally,this paper conducts a comprehensive examination of the algorithm’s robustness using metrics such as image correlation,information entropy,and number of pixel change rate(NPCR),confirming its high level of security.Overall,the algorithm can be applied in a multi-user and multi-level cloud service environment to realize the secure storage of carrier images and secret data.

船舶滚装通道设备的结构设计衡准研究

船舶滚装通道结构分析问题较为复杂,中国船级社《钢质海船入级规范》在车辆甲板尺寸要求等方面目前仍有适用性问题,因此有必要进一步研究。该文以船舶滚装通道的板、梁结构和主要构件为研究对象,采用理论公式推导和数值拟合方法,建立了车辆甲板板厚、骨材构件尺寸描述性要求,同时形成了符合国际船级社协会统一要求、涵盖各类载荷的通道主要支撑构件直接计算要求,并进行实例计算验证。结果表明:优化后的描述性要求和直接计算要求具有良好的适用性,对于提高滚装通道结构设计的安全性与轻量化水平具有重要意义。

分离式路线段高墩桥梁施工用大跨度桁架通道设计与施工

对某分离式路线段高墩桥梁间的桁架通道进行受力分析,通过有限元软件进行模拟研究,计算在不同荷载组合作用下结构的极限受力状态是否满足强度、刚度要求,并通过荷载试验进行校核,为桁架通道结构安全评定建立指导依据。介绍施工工艺流程与注意要点,提出桁架通道一般性施工方法。

淮北市小微湿地空间格局与可达性分析

淮北市常年煤炭开采造成地表沉陷积水,是小微湿地研究的理想对象。通过分类标准提取淮北市小微湿地图斑,测度其空间格局和可达性水平。结果表明:淮北市现有小微湿地1083个,总面积2857.09hm2,以小型湖泊湿地为主,斑块面积普遍偏小,破碎化程度高;全市和各县区的小微湿地在空间上均呈现出集聚分布的显著特征,在市域北部形成3个高密度聚集区,空间分布不均衡态势明显;小微湿地在河流和煤矿的缓冲区具有明显的分布规律性,由近到远分布数量梯次递减,是影响小微湿地形成的重要因素;小微湿地可达性水平在空间上表现出明显的“圈层状”特征,由高值区向外,平均可达时间呈圈层状的有规律递增,在市域最南端一带形成低值区。研究结果可为淮北市小微湿地管护和利用提供借鉴。

具有量子点插入层的阻变存储器电学特性研究

目的研究量子点插入层的氮离子吸附能力对AlN基阻变存储器的电学特性的影响。方法通过实验制备具有单层AlN阻变层的阻变存储器和具有AlN/PbS量子点堆叠结构的阻变存储器。通过材料表征、对器件电学特性表征以及对电流传导机制分析等手段研究具有AlN/PbS量子点堆叠结构的阻变存储器的电阻切换机制。结果与单层AlN基阻变存储器相比,AlN/PbS量子点堆叠结构阻变存储器具有优异的电阻开关特性,如Forming-free特性、低功耗特性以及优异的稳定性。结论器件的电阻开关过程显著受到PbS量子点插入层的调控作用,量子点插入层的引入、氮空位的分布情况和电场的分布情况是控制AlN基阻变存储器电阻切换性能的关键因素。