基于Tangle区块链的大数据访问控制研究

为了提高大数据访问控制效果,提出基于Tangle区块链的大数据访问控制研究.依据数据的主体属性以及数据库环境的安全情况,计算数据的敏感度,并通过数据的初始可信值与历史可信值的叠加计算获取数据的最终可信值,结合数据库系统设计中的访问逻辑空间制定访问控制约束规则,基于此,引入Tangle区块链技术构建数据访问控制模型,进而实现对大数据的访问控制.实例应用结果表明,应用所提方法对大数据进行访问控制后,其访问控制拓扑率在26%以内,数据被成功篡改的区块概率在0.4%以下,进一步说明了所提方法的大数据访问控制效果良好.

Monogamous nature of symmetric N-qubit states of the W class: Concurrence and negativity tangle

Using Majorana representation of symmetric N-qubit pure states, we have examined the monogamous nature of the family of states with two-distinct spinors, the W class of states. We have evaluated the N-concurrence tangle and showed that all the states in this family have vanishing concurrence tangle. The negativity tangle for the W class of states is shown to be non-zero, illustrating the fact that the concurrence tangle is always lesser than or equal to the negativity tangle in a pure N-qubit state.

基于Tangle网络的移动群智感知数据安全交付模型

针对现有群智感知平台在数据和酬金交付过程中存在的安全风险和隐私泄露问题,该文提出一种基于Tangle网络的分布式群智感知数据安全交付模型。首先,在数据感知阶段,调用局部异常因子检测算法剔除异常数据,聚类获取感知数据并确定可信参与者节点。然后,在交易写入阶段,使用马尔科夫蒙特卡洛算法选择交易并验证其合法性,通过注册认证中心登记完成匿名身份数据上传,并将交易同步写入分布式账本。最后,结合Tangle网络的累计权重共识机制,当交易安全性达到阈值时,任务发布者可进行数据和酬金的安全交付。仿真试验表明,在模型保护用户隐私的同时,增强了数据和酬金的安全交付能力,相比现有感知平台降低了时间复杂度和任务发布成本。

基于Tangle网络的群智感知用户可信激励方法

随着群智感知技术的广泛应用,用户参与度成为影响群智感知技术发展的关键问题,提出一种基于Tangle网络的群智感知用户可信激励方法.首先,基于Tangle网络构建群智感知网络模型,通过去中心化的Tangle网络来克服群智感知平台面临可信第三方参与的安全隐患,制定Tangle网络的可信度标准.然后,通过可信度来衡量用户权重,借此来评估交易的可信性,将感知任务分配给更可信的用户.最后,对用户上传的感知数据使用蒙特卡洛最大期望算法量化用户的工作量,支付相应报酬.通过基于真实数据集的仿真实验表明,所提方法能有效激励用户参与感知任务,同RSFP方法和CSII方法相比,所提方法在用户参与度上分别提升了0.379和0.067.

任意维数两体量子态的Tangle

利用任意维数两体量子态密度矩阵的concurrence判据、著名的Peres-Horodecki判据及重排判据之间的重要联系,来获得纠缠量tangle(即I-concurrence)的两个解析下界.

Neurofibrillary tangles in Alzheimer＇s disease： elucidation of the molecular mechanism by immunohistochemistry and tau protein phospho-proteomics

As a key contributor to memory storage, the synapse is one of the earliest affected neuronal components in Alzheimer＇s disease （AD）. Under physiological conditions, the synaptic con- nections between neurons undergo activity-dependent func- tional and morphological re-organisation. This dynamic, ＇plastic＇ neural ability critically depends on the structural integrity of the synapse. Thus, proteins that are implicated in preserving the organisation and dynamics of synaptic connections, including microtubules of the cytoskeleton and associated proteins, have attracted much focus for their involvement in the malfunction- ing AD synapse.

Forensic Pathological Expertise of Medical Tangle Analysis of 139 Autopsy Cases

In this article , we report 139 autopsy cases of medical tangle , which were examined by the Department of Forensic Pathology, Faculty of Medicine, Tongji Medical University from Jan. 1972 to Dec. 1992.The emphasis is put on analyses of the status of medical tangle autopsy in forensic pathology, involved medical departments , distribution of victim's age and sex , differences between clinical diagnosis and autoptical conclusion, the composition and causes of medical tangle. The associated problems in forensic pathological autopsy are also discussed.

Equivalence between Linear Tangle and Maximal Single Ideal

The concept of linear tangle was introduced as an obstruction to mixed searching number. The concept of (maximal) single ideal has been introduced as an obstruction to linear-width. Moreover, it was already known that mixed search number is equivalent to linear-width. Hence, by combining those results, we obtain a proof of the equivalence between linear tangle and maximal single ideal. This short report gives an alternative proof of the equivalence.

Comparative analysis of entanglement measures based on monogamy inequality

We evaluate the monogamy inequality for symmetric, non-symmetric pure states of importance in terms of squared concurrence, squared entanglement of formation, squared negativity of partial transpose and compare the corresponding tangles. We show that though concurrence and concurrence tangle are zero for two special classes of mixed entangled states, both negativity tangle and entanglement of formation（EOF） tangle turn out to be non-zero. A comparison of different tangles is carried out in each case and it is shown that while the concurrence tangle captures the genuine multiqubit entanglement in N-qubit pure states with N distinct spinors（containing GHZ and superposition of W-, obverse W states）either negativity tangle or EOF tangle is to be used as a better measure of entanglement in the W-class of states with two distinct spinors and in the special classes of mixed multiqubit states.

The Tangled Web of War

WHEN a mutinous band of the Democratic Republic of the Congo （DRC） military precipitated the latest eruption of war in June, it was hardly surprising given the fragile situation in Africa＇s second largest and natural resources endowed country. DRC has not known a continuous period of peace and tranquility since the mid-1990s.

The diagram category of framed tangles and invariants of quantized symplectic group

In this paper,we present a categorical version of the first and second fundamental theorems of the invariant theory for the quantized symplectic groups.Our methods depend on the theory of braided strict monoidal categories which are pivotal,more explicitly,the diagram category of framed tangles.

Essential Tori in 3-String Free Tangle Decompositions of Links

The author characterizes those link types which have 3-string essential free tangle decompositions and have essential tori in their exteriors.

Crowd sensing data delivery based on tangle DAG network

In view of the fact that current data delivery methods are not enough to meet the security requirements of today’s distributed crowd sensing,and the data delivery methods are not flexible enough,this paper proposes a crowd sensing data interaction method based on tangle directed acyclic graph(DAG)network.In this method,users and platforms are regarded as nodes of the network in the process of performing crowd sensing tasks.First,the heaviest chain is generated through the main chain strategy to ensure the stability of the network.Then,the hidden Markov model(HMM)prediction model is used to improve the correlation of the perceived data to improve the performance.Then,the confidential transaction and commitment algorithm is used to ensure the reliability of the transaction,overcome the security risks faced by the trusted third party,and simplify the group intelligence aware transaction mode.Finally,through simulation experiments,the security and feasibility of the group intelligence aware data delivery method based on tangle DAG network are verified.

Tangled Rankings

Declining recognition of top university lists prompts China to look for new ways to evaluate its higher learning institutions Zhejiang University for the first time has overtaken Peking University and Tsinghua University to rank No.1 on the latest list of Chinese college rankings.The rankings are an important part of the book Picking Your University

A Tangled Web

Syria’s ties to Russia and Iran make Western intervention unlikely After the fall of Muammar Gaddafi in Libya,Syria appeared to be the next target of Western powers.They have declared sanctions against Syria and publicly demanded Syrian President Bashar al-Assad step down.This Middle Eastern country now

Tangled Up in Bob

How does it feel,to be sitting at a Bob Dylan concert in Beijing?I had to keep asking myself that question when the living legend sauntered on to the stage at the Beijing Worker’s Gymnasium.The troubadour who blew in the wind like the pied piper all those years ago and has managed to roll

TANGLED WEB OF WIRED RADIO

The Mao-era public radio speakers are disappearing from China’s villages,but not everyone is happy中国农村的“大喇叭”广播曾给一代人留下了难忘的记忆,而现在它正离我们远去Wake up at 7 a.m.in rural China and you’ll likely hear the melodic strains of a love song,a popular talk show,or the local news wafting from an old speaker strung up on a telephone pole in the largest public space in the village.

Tau truncation in the pathogenesis of Alzheimer's disease:a narrative review

Alzheimer's disease is characterized by two major neuropathological hallmarks—the extracellularβ-amyloid plaques and intracellular neurofibrillary tangles consisting of aggregated and hyperphosphorylated Tau protein.Recent studies suggest that dysregulation of the microtubuleassociated protein Tau,especially specific proteolysis,could be a driving force for Alzheimer's disease neurodegeneration.Tau physiologically promotes the assembly and stabilization of microtubules,whereas specific truncated fragments are sufficient to induce abnormal hyperphosphorylation and aggregate into toxic oligomers,resulting in them gaining prion-like characteristics.In addition,Tau truncations cause extensive impairments to neural and glial cell functions and animal cognition and behavior in a fragment-dependent manner.This review summarizes over 60 proteolytic cleavage sites and their corresponding truncated fragments,investigates the role of specific truncations in physiological and pathological states of Alzheimer's disease,and summarizes the latest applications of strategies targeting Tau fragments in the diagnosis and treatment of Alzheimer's disease.

A blockchain-empowered authentication scheme for worm detection in wireless sensor network

Wireless Sensor Network(WSN)is a distributed sensor network composed a large number of nodes with low cost,low performance and self-management.The special structure of WSN brings both convenience and vulnerability.For example,a malicious participant can launch attacks by capturing a physical device.Therefore,node authentication that can resist malicious attacks is very important to network security.Recently,blockchain technology has shown the potential to enhance the security of the Internet of Things(IoT).In this paper,we propose a Blockchain-empowered Authentication Scheme(BAS)for WSN.In our scheme,all nodes are managed by utilizing the identity information stored on the blockchain.Besides,the simulation experiment about worm detection is executed on BAS,and the security is evaluated from detection and infection rate.The experiment results indicate that the proposed scheme can effectively inhibit the spread and infection of worms in the network.

Potential therapeutic roles of retinoids for prevention of neuroinflammation and neurodegeneration in Alzheimer’s disease

All retinoids, which can be natural and synthetic, are chemically related to vitamin A. Both natural and synthetic retinoids use specific nuclear receptors such as retinoic acid receptors and retinoid X receptors to activate specific signaling pathways in the cells. Retinoic acid signaling is extremely important in the central nervous system. Impairment of retinoic acid signaling pathways causes severe pathological processes in the central nervous system, especially in the adult brain. Retinoids have major roles in neural patterning, differentiation, axon outgrowth in normal development, and function of the brain. Impaired retinoic acid signaling results in neuroinflammation, oxidative stress, mitochondrial malfunction, and neurodegeneration leading to progressive Alzheimer’s disease, which is pathologically characterized by extra-neuronal accumulation of amyloid plaques(aggregated amyloid-beta) and intra-neurofibrillary tangles(hyperphosphorylated tau protein) in the temporal lobe of the brain. Alzheimer’s disease is the most common cause of dementia and loss of memory in old adults. Inactive cholinergic neurotransmission is responsible for cognitive deficits in Alzheimer’s disease patients. Deficiency or deprivation of retinoic acid in mice is associated with loss of spatial learning and memory. Retinoids inhibit expression of chemokines and neuroinflammatory cytokines in microglia and astrocytes, which are activated in Alzheimer’s disease. Stimulation of retinoic acid receptors and retinoid X receptors slows down accumulation of amyloids, reduces neurodegeneration, and thereby prevents pathogenesis of Alzheimer’s disease in mice. In this review, we described chemistry and biochemistry of some natural and synthetic retinoids and potentials of retinoids for prevention of neuroinflammation and neurodegeneration in Alzheimer’s disease.