Cross-Domain Authentication Scheme Based on Blockchain and Consistent Hash Algorithm for System-Wide Information Management

System-wide information management(SWIM)is a complex distributed information transfer and sharing system for the next generation of Air Transportation System(ATS).In response to the growing volume of civil aviation air operations,users accessing different authentication domains in the SWIM system have problems with the validity,security,and privacy of SWIM-shared data.In order to solve these problems,this paper proposes a SWIM crossdomain authentication scheme based on a consistent hashing algorithm on consortium blockchain and designs a blockchain certificate format for SWIM cross-domain authentication.The scheme uses a consistent hash algorithm with virtual nodes in combination with a cluster of authentication centers in the SWIM consortium blockchain architecture to synchronize the user’s authentication mapping relationships between authentication domains.The virtual authentication nodes are mapped separately using different services provided by SWIM to guarantee the partitioning of the consistent hash ring on the consortium blockchain.According to the dynamic change of user’s authentication requests,the nodes of virtual service authentication can be added and deleted to realize the dynamic load balancing of cross-domain authentication of different services.Security analysis shows that this protocol can resist network attacks such as man-in-the-middle attacks,replay attacks,and Sybil attacks.Experiments show that this scheme can reduce the redundant authentication operations of identity information and solve the problems of traditional cross-domain authentication with single-point collapse,difficulty in expansion,and uneven load.At the same time,it has better security of information storage and can realize the cross-domain authentication requirements of SWIM users with low communication costs and system overhead.KEYWORDS System-wide information management(SWIM);consortium blockchain;consistent hash;cross-domain authentication;load balancing.

Consortium Chain Consensus Vulnerability and Chain Generation Mechanism

Effectively identifying and preventing the threat of Byzantine nodes to the security of distributed systems is a challenge in applying consortium chains.Therefore,this paper proposes a new consortium chain generation model,deeply analyzes the vulnerability of the consortium chain consensus based on the behavior of the nodes,and points out the effects of Byzantine node proportion and node state verification on the consensus process and system security.Furthermore,the normalized verification node aggregation index that represents the consensus ability of the consortium organization and the trust evaluation function of the verification node set is derived.When either of the two is lower than the threshold,the consortium institution or the verification node set members are dynamically adjusted.On this basis,an innovative consortium chain generation mechanism based on the Asynchronous Binary Byzantine Consensus Mechanism(ABBCM)is proposed.Based on the extended consortium chain consensus mechanism,a certain consensus value set can be combined into multiple proposals,which can realize crossdomain asynchronous message passing between multi-consortium chains without reducing the system’s security.In addition,experiments are carried out under four classical Byzantine Attack(BA)behaviors,BA1 to BA4.The results show that the proposed method can obtain better delay than the classical random Byzantine consensus algorithm Coin,effectively improving the consensus efficiency based on asynchronous message passing in the consortium chain and thus meeting the throughput of most Internet of Things(IoT)applications.

Vertical Federated Learning Based on Consortium Blockchain for Data Sharing in Mobile Edge Computing

The data in Mobile Edge Computing(MEC)contains tremendousmarket value,and data sharing canmaximize the usefulness of the data.However,certain data is quite sensitive,and sharing it directly may violate privacy.Vertical Federated Learning(VFL)is a secure distributed machine learning framework that completes joint model training by passing encryptedmodel parameters rather than raw data,so there is no data privacy leakage during the training process.Therefore,the VFL can build a bridge between data demander and owner to realize data sharing while protecting data privacy.Typically,the VFL requires a third party for key distribution and decryption of training results.In this article,we employ the consortium blockchain instead of the traditional third party and design a VFL architecture based on the consortium blockchain for data sharing in MEC.More specifically,we propose a V-Raft consensus algorithm based on Verifiable Random Functions(VRFs),which is a variant of the Raft.The VRaft is able to elect leader quickly and stably to assist data demander and owner to complete data sharing by VFL.Moreover,we apply secret sharing todistribute the private key to avoid the situationwhere the training result cannot be decrypted if the leader crashes.Finally,we analyzed the performance of the V-Raft and carried out simulation experiments,and the results show that compared with Raft,the V-Raft has higher efficiency and better scalability.

Asymmetric Consortium Blockchain and Homomorphically Polynomial-Based PIR for Secured Smart Parking Systems

In crowded cities,searching for the availability of parking lots is a herculean task as it results in the wastage of drivers’time,increases air pollution,and traffic congestion.Smart parking systems facilitate the drivers to determine the information about the parking lot in real time and book them depending on the requirement.But the existing smart parking systems necessitate the drivers to reveal their sensitive information that includes their mobile number,personal identity,and desired destination.This disclosure of sensitive information makes the existing centralized smart parking systems more vulnerable to service providers’security breaches,single points of failure,and bottlenecks.In this paper,an Improved Asymmetric Consortium Blockchain and Homomorphically Computing Univariate Polynomial-based private information retrieval(IACB-HCUPPIR)scheme is proposed to ensure parking lots’availability with transparency security in a privacy-preserving smart parking system.In specific,an improved Asymmetric Consortium Blockchain is used for achieving secure transactions between different parties interacting in the smart parking environment.It further adopted the method of Homomorphically Computing Univariate Polynomial-based private information retrieval(HCUPPIR)scheme for preserving the location privacy of drivers.The results of IACB-HCUPPIR confirmed better results in terms of minimized computation and communication overload with throughput,latency,and response time with maximized drivers’privacy preservation.Moreover,the proposed fully homomorphic algorithm(FHE)was compared against partial-homomorphic encryption(PHE)and technique without encryption and found that the proposed model has quick communication in allocating the parking slots starting with 24.3 s,whereas PHE starts allocating from 24.7 s and the technique without encryption starts at 27.4 s.Thus,we ensure the proposed model performs well in allocating parking slots with less time and high security with privacy preservation.

Directed Acyclic Graph Blockchain for Secure Spectrum Sharing and Energy Trading in Power IoT

Peer-to-peer(P2P)spectrum sharing and energy trading are promising solutions to locally satisfy spectrum and energy demands in power Internet of Things(IoT).However,implementation of largescale P2P spectrum sharing and energy trading confronts security and privacy challenges.In this paper,we exploit consortium blockchain and Directed Acyclic Graph(DAG)to propose a new secure and distributed spectrum sharing and energy trading framework in power IoT,named spectrum-energy chain,where a set of local aggregators(LAGs)cooperatively confirm the identity of the power devices by utilizing consortium blockchain,so as to form a main chain.Then,the local power devices verify spectrum and energy micro-transactions simultaneously but asynchronously to form local spectrum tangle and local energy tangle,respectively.Moreover,an iterative double auction based micro transactions scheme is designed to solve the spectrum and energy pricing and the amount of shared spectrum and energy among power devices.Security analysis and numerical results illustrate that the developed spectrum-energy chain and the designed iterative double auction based microtransactions scheme are secure and efficient for spectrum sharing and energy trading in power IoT.

Research and Practice on the Construction of Municipal Industry-Education Consortium Based on the Integration of Industrial Chain,Innovation Chain,Talent Chain,and Education Chain

The construction of a municipal industry-education consortium is one of the important measures for the“one body,two wings,and five key points”reform of China’s modern vocational education system in the new era.It is of great significance for the integrated promotion of the three major national strategies of education,technology,and talent.Exploring the construction path of municipal industry-education consortia from the perspective of“four-chain integration”is essential for improving the quality of vocational education talents,comprehensively promoting local economic and social development,and serving the national strategy of revitalizing the country through science and education.The new generation of information technology industry-education consortium in Chengdu actively explores new paths of industry-education integration,science-education integration,and vocational-education integration.It has formed a“park+alliance”to establish a diversified collaborative construction and management mechanism,a“professional+industry”school-enterprise cooperation to promote industrial transformation and upgrading,a“teaching+research and development”to build an industry-university research innovation platform to empower high-quality development,and a“cultivation+employment”to explore a matrix style talent cultivation model,thus promoting regional governments,industries enterprises,and higher education institutions.Fully leveraging complementary advantages involves capitalizing on the spatial cluster effect.It requires a foundation in the education chain,guided by the industrial chain,activation of the innovation chain,establishment of a talent chain,enhancement of the value chain,and the promotion of a modern vocational education structure.This structure should align with market demand and industry structure,ultimately promoting regional economic and social development.

《地平线报告》2015基础教育版简评

年初《地平线报告》（2015高等教育版）发行,之后,其基础教育版也得以发布,特别是不久前,北京开放大学作为美国新媒体联盟的战略合作伙伴,承担了报告中文版的翻译、出版和推广工作,使得大中华地区的教育工作者和教育管理人员得以享受这一战略预测性成果,这实在是一件可喜可贺的事情。

当前“出口吨位计划”市场环境与2008年比较分析

2016年2月4日,国际三方橡胶理事会（ITRC：International Tripartite Rubber Council）通过国际橡胶联盟有限公司（IRCo：International Rubber Consortium Limited）的网站发布公告,泰国、印度尼西亚和马来西亚政府同意执行天然橡胶＂出口吨位计划＂（AETS：Agreed Export Tonnage Scheme）,

工业互联网联盟与工业4.0平台的合作始末

2016年3月2日,工业4.0平台（Plattform Industrie 4.0）和工业互联网联盟（Industrial Internet Consortium,IIC）的代表在瑞士苏黎世会面,探讨在双方各自推出的参考架构——RAMI 4.0和IIRA——之间建立某种一致性的可能。会议取得了成功,成果包括：双方就两种模型的天然互补性达成共识;形成了初始映射图,以显示两种模型其元素之间的直接关系，

爱尔兰为中学领导提供研究生课程

据爱尔兰教育与技能部网站2016年12月12日报道,爱尔兰教育与技能部部长理查德·布鲁顿（Richard Bruton）宣布在中学领导中推行研究生课程,为学校领导提供培训。第一批＂学生＂将于2017年9月入学。招标完成后,布鲁顿部长和大学联合会（Consortium of Universities）签订协议。学校领导中心（Centre for School Leadership）将与大学联合会进行密切合作。

荷兰温室联盟利用地热能源加温温室

最近,为了用可持续的方式生产作物,由9家荷兰温室企业组成的温室联盟开始使用地热能源为温室加温。2014年,该联盟的地热井项目资金筹措到位,并于2015年开始钻井施工,抽取热水。2016年1月下旬,Geothermal Vierpolders公司也开始使用地热能源给玻璃温室加温,这个温室位于荷兰西南部的鹿特丹港口枢纽附近,占地约49 hm^2,主要种植番茄和茄子。Geothermal Vierpolders公司的负责人Paul

首届(中学生)国际数学建模挑战赛(IMMC)举行

过去20多年以来,大学生数学建模教学与竞赛活动在世界许多国家和地区受到越来越多的关注,它对学生创新能力的培养和综合素质的提高起到了非常积极的作用。数学建模的训练体现了应用驱动数学发展的理念,而这种理念应当适时向中学教育延伸。荷兰、丹麦、德国、俄罗斯、美国和新加坡等许多国家有各种形式的探索,在国内,北京和上海等地区也组织了中学生数学建模竞赛等活动。

使用开源软件构建WMS服务器——PHP等开源工具在WebGIS中的应用

Open Geospatial Consortium,Inc.(OGC)提出的Web Map Service(WMS)接口规范为网络地图服务器的开发提供了标准。用户使用简单的Web浏览器即可访问按照WMS标准建立的网络地图服务器,获得地图图像,同时也有效解决了地图叠加问题。本文介绍如何使用PHP结合其它开源工具构建一个开源的WMS服务器——PHPMyWMS,并在此基础上实现WMS的三个基本操作(GetMap,GetCapabilities,GetFeatureInfo)。

Role of genetics in the diagnosis and prognosis of Crohn's disease

Considering the epidemiological, genetic and immunological data, we can conclude that the inflammatory bowel diseases are heterogeneous disorders of multifactorial etiology in which hereditability and environment interact to produce the disease. It is probable that patients have a genetic predisposition for the development of the disease coupled with disturbances in immunoregulation. Several genes have so far been related to the diagnosis of Crohn's disease. These genes are related to innate pattern recognition receptors, to epithelial barrier homeostasis and maintenance of epithelial barrier integrity, to autophagy and to lymphocyte differentiation. So far, the strongest and most replicated associations with Crohn's disease have been demonstrated with NOD2 , IL23R and ATG16L1 genes. Many genes have so far been implicated in the prognosis of Crohn's disease and many attempts have been made for classification of genetic profiles in Crohn's disease.CARD15 seems to be not only a susceptibility gene, but also a disease-modifier gene for Crohn's disease. Enriching our understanding of Crohn's disease genetics is of value, but when combining genetic data with functional data the outcome could be of major importance to clinicians.

A Consortium Blockchain Paradigm on Hyperledger-Based Peer-to-Peer Lending System

This paper focuses on how to use consortium blockchain to improve the regulation of peer-to-peer(P2 P) lending market. The partial decentralized consortium blockchain with limited pre-set nodes can well improve transparency and security, which is suitable for financial regulation. Considering irregularities of the P2P lending market, the Hyperledger-based Peer-to-Peer Lending System(HyperP2PLS) is proposed. First elaborate the application scenario and business logic of the system, where a national P2P Lending Trading Center will be established to integrate all transactions and information of P2P lending market. Then construct the system architecture consisting of the blockchain network, HTTP server, and applications. The algorithm of implementation process and the web application for users have been well illustrated. The performance analysis shows that HyperP2PLS can guarantee the reliability, safety, transparency and efficiency.

Exploration of the key microbes and composition stability of microbial consortium GF-20 with efficiently decomposes corn stover at low temperatures

The microbial consortium GF-20(GF-20) can efficiently decompose corn stover at low temperatures. The present study explored the key microbes of GF-20 and evaluated different culture conditions on its composition stability to promote the utilization of corn stover decomposing microbes in low temperature regions. GF-20 was subcultured to the 15 th generation under different temperatures, pHs, carbon, and nitrogen sources. Then, the dynamics of fermenting pH, cellulose enzyme activities, carbohydrate concentration, and oxidation reduction potential were determined to estimate the degradation efficiency of corn stover with GF-20. Furthermore, the structural stability and functional microbes of GF-20 were identified on the basis of PCR-denaturing gradient gel electrophoresis(DGGE) profiling and principal component analysis. The results showed that the offspring of GF-20 subcultured under different temperatures(4–30°C) and pH(6.0–9.0) conditions maintained stable growth, decomposition function, and composition structure. Furthermore, consortia GF-20 had a stable composition structure, which induced GF-20 to secrete cellulose and promote substrate decomposition as corn stover and ammonium were used as sources of carbon and nitrogen, respectively. According to the PCR-DGGE profiles, the key strains of GF-20 were determined to be Bacillus licheniformis, Cellvibrio mixtus subsp. mixtus, Bacillus tequilensis, Clostridium populeti, and Clostridium xylanolyticum.

Isolation and Characteristics of a Microbial Consortium for Effectively Degrading Phenanthrene

A microbial consortium （named W4） capable of aerobic biodegradation of solid phenanthrene as the sole source of carbon and energy was isolated by selective enrichment from petroleum-contaminated soil in the Henan oilfield, China. The strains of the consortium were identified as Sphingomonas cloacae, Rhizobium sp., Pseudomonas aeruginosa and Achromobacter xylosoxidans respectively by means of genetic methods. The major metabolites of phenanthrene were analyzed by gas chromatography-mass spectrometry （GC-MS）. The biodegradation percentage of solid phenanthrene at 200 mg/L in liquid medium after 7 days of growth was greater than 99%. The degradation of phenanthrene was compared between individual predominant strains and the microbial consortium in different treatment processes. The microbial consortium showed a significant improvement of phenanthrene degradation rates in either static or shaking culture. The degradation percentage of phenanthrene by the consortium W4 decreased to some degree when C 16 coexisted, however it was hardly affected by C30. Furthermore, the ability of consortium W4 to remediate oil sludge from the Dagang oil refinery was studied by composting, and it was found that the consortium W4 could obviously remove polycyclic aromatic hydrocarbons （PAils） and paraffinic hydrocarbons. All the results indicated that the microbial consortium W4 had a promising application in bioremediation of oil-contaminated environments and could be potentially used in microbial enhanced oil recovery （MEOR）.

Role of genetics in the diagnosis and prognosis of Crohn's disease

Considering epidemiological,genetic and immunological data,we can conclude that the inflammatory bowel diseases are heterogeneous disorders of multifactorial etiology in which hereditability and environment interact to produce the disease.It is probable that patients have a genetic predisposition for the development of the disease coupled with disturbances in immunoregulation.Several genes have been so far related to the diagnosis of Crohn's disease.Those genes are related to innate pattern recognition receptors,to epithelial barrier homeostasis and maintenance of epithelial barrier integrity,to autophagy and to lymphocyte differentiation.So far,the most strong and replicated associations with Crohn's disease have been done with NOD2,IL23R and ATG16L1 genes.Many genes have so far been implicated in prognosis of Crohn's disease and many attempts have been made to classify genetic profiles in Crohn's disease.CARD15 seems not only a susceptibility gene,but also a disease-modifier gene for Crohn's disease.Enriching our understanding on Crohn's disease genetics is important but when combining genetic data with functional data the outcome could be of major importance to clinicians.

Microbial oxidation of refractory gold sulfide concentrate by a native consortium

A defined mesophilic consortium including an iron oxidizing bacterium and a sulfur oxidizing bacterium was constructed to evaluate its ability for bioleaching a flotation concentrate from Andacollo mine in Neuquén,Argentina.Experiments were performed in shake flasks with a pulp density of10%(w/v),using a basal salt medium containing ferrous iron at pH1.8.The leaching solutions were analyzed for pH,redox potential(using specifics electrodes),ferrous iron(by UV-Vis spectrophotometry)and metal concentrations(by atomic absorption spectroscopy).The results showed that the consortium was able to reduce the refractory behavior of the concentrate,allowing91.6%of gold recovery;at the same time,high dissolution of copper and zinc was reached.These dissolutions followed a shrinking core kinetic model.According to this model,the copper solubilization was controlled by diffusion through a product layer(mainly jarosite),while zinc dissolution did not show a defined control step.This designed consortium,composed of bacterial strains with specific physiological abilities,could be useful not only to optimize gold recovery but also to decrease the leachates metallic charge,which would be an environmental advantage.