Network Access Mechanisms and Security Issues under the Cloud Service Architecture

Currently, under the cloud service architecture, the increasing importance of network security and security issues are still emerging. With the rapid development of the network platform, it is connected to the number and size of the trusted computing environment for all kinds of applications that are rapidly expanding, ever-changing network health, network time being emergencies, assault, failure, threat of disaster, its safety, survivability and availability of face serious challenges. Although TNC Working Group made safe and reliable framework from the network access layer, it is not at the level of user access, system access levels and further given the level of situational awareness and effective solutions.

Analysis and modeling of resistive switching mechanisms oriented to resistive random-access memory

With the progress of the semiconductor industry,the resistive random-access memory（RAM） has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on the resistive switching characteristics of different materials and the analysis of resistive switching mechanisms.We discuss the resistive switching mechanisms of different materials in this paper and analyze the differences of those mechanisms from the view point of circuitry to establish their respective circuit models.Finally,simulations are presented.We give the prospect of using different materials in resistive RAM on account of their resistive switching mechanisms,which are applied to explain their resistive switchings.

Spatial Differentiation and Influencing Mechanism of Medical Care Accessibility in Beijing:A Migrant Equality Perspective

Spatial equality of access to basic public services, especially medical care services which are directly related to life safety, is the first step to achieve the goal of equalization of basic public services for all the people proposed by central government of China. Using the spatial analysis and the statistical analysis, this study evaluates the spatial differentiation of medical care facilities accessibility by constructing STT(Shortest Travel-Time) and SAI(Spatial Accessibility Index). And then this study explores the neighborhood effects on the medical care facilities accessibility in Beijing, with a particular focus on the effect of neighborhood migrant proportion by constructing spatial dependent regression model. The spatial accessibility analysis of medical care facilities show that the spatial distribution of medical care facilities was basically consistent with administrative regions but not with population demands. Bivariate LISA cluster maps identify that suburban areas are the overlapped clusters of high percent of migrants and limited medical care services. This is associated with the public service allocation rule in China, which stresses equality within urban areas and within rural areas but overlooks equality between urban areas and rural areas; and stresses local resident demands but overlooks migrant demands. To estimate the effects on medical care accessibility of neighborhood migrant proportion, spatial dependence models are applied due to spatial dependence of accessibility of medical care facilities. The regression results show that neighborhoods with high percent of migrants, even conditioning on neighborhood SES, are related to limited spatial accessibility of medical care services. Besides neighborhood characteristics, another important factor influencing spatial accessibility of medical care services is the process of spatial spillover effects. This indicates that the attenuate accessibility of medical care services for migrants is not only because of their own constraints but also because of their proximity to other disadvantaged neighborhoods. Therefore, it is urgently needed to increase the medical facilities in the suburban areas, to take into account migrants' demands and to reduce residential segregation between local residents and migrants for local governments to achieve the goal of equalization of medical care service.

Hybrid Channel Access Mechanism Based on Coexistence Scenario of NR-Unlicensed

With the rapid development of 5G NR(New Radio),the explosive increment of traffic amount is calling the utilization of unlicensed band.3GPP has proposed LAA(Licensed Assisted Access)to use LTE in unlicensed band and pointed out that NR-U(NR-Unlicensed)can reuse most designs of it.However,the existing channel access mechanism of LAA is conservative under the coexistence scenario of NR-U,which leads to the waste of time resource.To address the problem this paper proposes a hybrid channel access mechanism to take advantage of the LBT(Listen-Before-Talk)mechanism of LAA when channel is quite busy and transmit directly with reduced power when it is relatively idle.The channel busy degree is judged by a series of periodically updated adaptive thresholds.System-level simulation verifies that under the coexistence scenario of NR-U the proposed mechanism can achieve higher UPT(User Perceived Throughput)and lower delay than other channel access mechanisms.

Regarding the Regulatory Sandbox Route and Mechanism for Governance of Artificial Intelligence

The main challenge in AI governance today is striking a balance between controlling AI dangers and fostering AI innovation.Regulators in a number of nations have progressively extended the regulatory sandbox,which was first implemented in the banking sector,to AI governance in an effort to reduce the conflict between regulation and innovation.The AI regulatory sandbox is a new and feasible route for AI governance in China that not only helps to manage the risks of technology application but also prevents inhibiting AI innovation.It keeps inventors'trial-and-error tolerance space inside the regulatory purview while offering a controlled setting for the development and testing of novel AI that hasn't yet been put on the market.By providing full-cycle governance of AI with the principles of agility and inclusive prudence,the regulatory sandbox offers an alternative to the conventional top-down hard regulation,expost regulation,and tight regulation.However,the current system also has inherent limitations and practical obstacles that need to be overcome by a more rational and effective approach.To achieve its positive impact on AI governance,the AI regulatory sandbox system should build and improve the access and exit mechanism,the coordination mechanism between the sandbox and personal information protection,and the mechanisms of exemption,disclosure,and communication.

Multi-source heterogeneous data access management framework and key technologies for electric power Internet of Things

The power Internet of Things(IoT)is a significant trend in technology and a requirement for national strategic development.With the deepening digital transformation of the power grid,China’s power system has initially built a power IoT architecture comprising a perception,network,and platform application layer.However,owing to the structural complexity of the power system,the construction of the power IoT continues to face problems such as complex access management of massive heterogeneous equipment,diverse IoT protocol access methods,high concurrency of network communications,and weak data security protection.To address these issues,this study optimizes the existing architecture of the power IoT and designs an integrated management framework for the access of multi-source heterogeneous data in the power IoT,comprising cloud,pipe,edge,and terminal parts.It further reviews and analyzes the key technologies involved in the power IoT,such as the unified management of the physical model,high concurrent access,multi-protocol access,multi-source heterogeneous data storage management,and data security control,to provide a more flexible,efficient,secure,and easy-to-use solution for multi-source heterogeneous data access in the power IoT.

基于Access数据库的类四杆五杆机构连杆曲线查询

提出以 Access数据库形式存储类四杆五杆机构的连杆曲线 ,用 SQL 查询语句从库中查出满足一定精度的相似曲线及相应的机构参数 ,然后用机构动态演示及曲线重叠比较验证结果。经实践检验 ,该方法简便实用。

IEEE 802.11e Medium Access Control层QoS机制的改进研究

针对IEEE802.11e Medium Access Control层的QoS机制高负载时存在远端节点冲突和低优先级业务资源被耗尽的问题,提出在牺牲较小带宽的基础上增加一条忙音信道,取代CTS帧在数据信道上的广播,减少远端节点的冲突.仿真结果表明,该方案具有较小的冲突概率,有效地减少了远端节点冲突.同时提出一个解决公平性问题的新思路:在避退时间发送忙音抢占信道,以期提高低优先级业务的接入概率.

MTBAC： A Mutual Trust Based Access Control Model in Cloud Computing

As a new computing mode,cloud computing can provide users with virtualized and scalable web services,which faced with serious security challenges,however.Access control is one of the most important measures to ensure the security of cloud computing.But applying traditional access control model into the Cloud directly could not solve the uncertainty and vulnerability caused by the open conditions of cloud computing.In cloud computing environment,only when the security and reliability of both interaction parties are ensured,data security can be effectively guaranteed during interactions between users and the Cloud.Therefore,building a mutual trust relationship between users and cloud platform is the key to implement new kinds of access control method in cloud computing environment.Combining with Trust Management(TM),a mutual trust based access control(MTBAC) model is proposed in this paper.MTBAC model take both user's behavior trust and cloud services node's credibility into consideration.Trust relationships between users and cloud service nodes are established by mutual trust mechanism.Security problems of access control are solved by implementing MTBAC model into cloud computing environment.Simulation experiments show that MTBAC model can guarantee the interaction between users and cloud service nodes.

基于Access数据库的机加工车间管理系统的开发与应用

Excel和Word等应用程序是用来进行日常管理数据的记录和统计,这种方法使各项管理信息无法形成科学的系统,资源不易实现共享,数据的计算和处理也很难实现计算机化。现借助Access数据库开发了一个小型的机加工车间管理系统,在实际应用时取得了良好效果,不但从根本上解决了上述问题,弥补了ERP系统的不足之处,而且各项管理工作得以理顺,减轻了管理人员的工作负担和压力。

Statistical-mechanical analysis of multiuser channel capacity with imperfect channel state information

In this paper, the effect of imperfect channel state information at the receiver, which is caused by noise and other interference, on the multi-access channel capacity is analysed through a statistical-mechanical approach. Replica analyses focus on analytically studying how the minimum mean square error （MMSE） channel estimation error appears in a multiuser channel capacity formula. And the relevant mathematical expressions are derived. At the same time, numerical simulation results are demonstrated to validate the Replica analyses. The simulation results show how the system parameters, such as channel estimation error, system load and signal-to-noise ratio, affect the channel capacity.

Fuzzy User Access Trust Model for Cloud Access Control

Cloud computing belongs to a set of policies,protocols,technologies through which one can access shared resources such as storage,applications,net-works,and services at relatively low cost.Despite the tremendous advantages of cloud computing,one big threat which must be taken care of is data security in the cloud.There are a dozen of threats that we are being exposed to while avail-ing cloud services.Insufficient identity and access management,insecure inter-faces and Applications interfaces(APIs),hijacking,advanced persistent threats,data threats,and many more are certain security issues with the cloud platform.APIs and service providers face a huge challenge to ensure the security and integ-rity of both network and data.To overcome these challenges access control mechanisms are employed.Traditional access control mechanisms fail to monitor the user operations on the cloud platform and are prone to attacks like IP spoofing and other attacks that impact the integrity of the data.For ensuring data integrity on cloud platforms,access control mechanisms should go beyond authentication,identification,and authorization.Thus,in this work,a trust-based access control mechanism is proposed that analyzes the data of the user behavior,network beha-vior,demand behavior,and security behavior for computing trust value before granting user access.The method that computes thefinal trust value makes use of the fuzzy logic algorithm.The trust value-based policies are defined for the access control mechanism and based on the trust value outcome the access control is granted or denied.

QoS Mechanism in EPS

To adapt to the development of mobile communication technologies in the next 10-year timeframe and better meet an ever-increasing demand for data services,3GPP has started the Long Term Evolution(LTE) and System Architecture Evolution(SAE) study projects.In view of the high-speed and bursty feature of future data services,the Evolved Packet System(EPS) makes quite a few enhancements and improvements in Quality of Service(QoS).By introducing such technologies as default bearer and aggregate resource scheduling,the EPS truly realizes the objective of 'Always Online' for users,improves data rates and thus enhances user experience ultimately.Furthermore,an appropriate mapping between the EPS QoS Class Identifier(QCI) parameter and Universal Mobile Telecommunication System (UMTS) QoS parameter is designed regarding future interoperability scenario between UMTS Terrestrial Radio Access Network(UTRAN) and Evolved UTRAN (E-UTRAN).

挑战与应对:“双减”政策下我国青少年体育培训的实践逻辑

“双减”政策的实施有效推动了我国青少年体育的改革进程,青少年体育培训作为非学科类课外培训活动的重要组成部分,也迎来了新的发展机遇。“双减”政策下,我国青少年体育培训发展面临如下挑战:管理部门介入无序,参与主体协同程度不高;市场准入制度宽松,体培硬件条件参差不齐;课程供给同质化较高,服务对象需求难以满足;违规营销现象频发,正常市场秩序面临冲击。提出构建多元主体监管体系,优化体育培训发展生态;健全体育培训机构资质认定机制,提升市场准入门槛;提高体育培训课程供给质量,满足不同消费群体需求;规范体育培训机构经营管理,建立良好市场信誉体系。

改进PBFT算法的配电物联网接入认证方法

随着物联网与配电网深度融合,海量终端设备接入系统给配电物联网安全稳定运行带来巨大挑战。针对传统身份认证方式过于中心化且无法承载大规模终端等现状,设计一种基于区块链共识机制的配电物联网终端接入认证方法。由配电物联网网关负责对待接入终端节点登记注册,采用共识算法进行分布式认证,将合法终端上链存储。在传统PBFT算法的基础上,设计了配电物联网终端共识算法。该算法引入权重机制,根据终端节点权重选取认证节点,缩小共识规模;引入可验证随机函数增强主节点安全,避免启动视图切换协议,提高共识效率;结合实际应用场景优化一致性协议,降低通信开销。实验分析表明该方法可有效规避多种网络攻击,通信开销和吞吐量优于其他方法,系统抗攻击性较强,满足配电物联网对认证效率和系统可靠性等要求。

面向无线互联的云计算网络安全架构设计与实现

随着云计算技术的广泛应用和无线网络技术的快速发展,面向无线互联的云计算网络安全架构设计与实现成为一个重要议题。文章针对无线互联环境下云计算的网络安全挑战,提出了一种新的网络安全架构。首先,分析了无线互联环境特有的安全挑战,如数据传输的安全性、网络访问控制以及针对多样化威胁的防御机制。随后,提出了一种结合云计算特性的网络安全架构,这一架构包括但不限于数据加密技术、访问控制策略、虚拟安全技术以及基于云的监控和响应机制。文章研究的网络安全架构可以提高无线互联环境下云计算网络的安全性,确保数据的保密性和网络的完整性。

基于准入机制的高校实验室安全管理研究

文章在分析国内高校实验室事故起数和原因的基础上,指出实验室准入制度的建立和完善可有效地预防实验室安全事故,从多方面建立和完善了实验室安全准入制度,并给出实验室安全准入制度实施的保障措施。通过研究,可从根源上减少实验室安全事故的发生,拓宽实验室安全管理研究的范围。

变电所门的设计要点简析

梳理变电所门的主要作用和设置要点;介绍变电所门的常见的“机械锁”和“门禁”两种形式的管理方式;结合气体灭火系统的特点,分别对两种管理方式下变电所的外门和相邻变电所之间双向开启弹簧门的特点进行分析,提出一种验证灭火剂喷射时能否顶开变电所门的公式,并结合气体灭火系统的要求提出合理建议;最后,分析低压柜长度对门设置的影响并提出建议。

基于Langer线的穿刺体位对肿瘤化疗患者输液港难免性医用黏胶相关皮肤损伤的预防效果研究

目的探究基于Langer线的无损伤针穿刺体位对肿瘤化疗患者输液港难免性黏胶相关皮肤损伤的预防效果。方法通过平行胸部Langer线对床头抬高60~90°和平卧位穿刺进行皮肤软组织力学、表皮屏障功能理论分析,然后选取2019年5月至2020年5月南京医科大学第一附属医院肿瘤科79例植入胸壁输液港、既往应用Ⅳ3000及液体敷料皮肤保护性屏障仍出现输液港黏胶相关性皮肤损伤的患者为研究对象。采用前瞻性自身前后对照,干预前采用平卧位穿刺,干预后床头抬高60~90°穿刺,比较两种穿刺体位对输液港黏胶相关性皮肤损伤预防效果和带针期间舒适度的影响。结果干预后患者输液港黏胶相关性皮肤相关性损伤总发生率较干预前显著降低(P<0.001),机械性损伤发生率、接触性皮炎发生率较干预前显著降低(均P<0.05),输液港带针期间舒适度较干预前明显提高(P<0.001),且不增加患者穿刺时的疼痛感(P=0.692)。结论床头抬高60~90°穿刺可降低肿瘤化疗患者输液港难免性黏胶相关皮肤损伤,提高患者带针期间的舒适度。

基于融合序列的远控木马流量检测模型

针对现有远控木马流量检测方法泛化能力较弱、表征能力有限和预警滞后等问题,提出了一种基于融合序列的远控木马流量检测模型。通过深入分析正常应用网络流量与远控木马流量在包长序列、包负载长度序列和包时间间隔序列方面的差异,将流量表征为融合序列。将融合序列输入Transformer模型,利用多头注意力机制与残差连接挖掘融合序列内在联系,学习木马通信行为模式,有效地提升了对远控木马流量的检测能力与模型的泛化能力。所提模型仅需提取网络会话的前20个数据包进行检测,就能够在木马入侵早期做出及时预警。对比实验结果表明,模型不仅在已知数据中具有优异的检测效果,在未知流量测试集上同样表现出色,相比当前已有的深度学习模型,各项检测指标有较大提升,在远控木马流量检测领域具备实际应用价值。