Starlet:Network defense resource allocation with multi-armed bandits for cloud-edge crowd sensing in IoT

The cloud platform has limited defense resources to fully protect the edge servers used to process crowd sensing data in Internet of Things.To guarantee the network's overall security,we present a network defense resource allocation with multi-armed bandits to maximize the network's overall benefit.Firstly,we propose the method for dynamic setting of node defense resource thresholds to obtain the defender(attacker)benefit function of edge servers(nodes)and distribution.Secondly,we design a defense resource sharing mechanism for neighboring nodes to obtain the defense capability of nodes.Subsequently,we use the decomposability and Lipschitz conti-nuity of the defender's total expected utility to reduce the difference between the utility's discrete and continuous arms and analyze the difference theoretically.Finally,experimental results show that the method maximizes the defender's total expected utility and reduces the difference between the discrete and continuous arms of the utility.

Distributed Weighted Data Aggregation Algorithm in End-to-Edge Communication Networks Based on Multi-armed Bandit

As a combination of edge computing and artificial intelligence,edge intelligence has become a promising technique and provided its users with a series of fast,precise,and customized services.In edge intelligence,when learning agents are deployed on the edge side,the data aggregation from the end side to the designated edge devices is an important research topic.Considering the various importance of end devices,this paper studies the weighted data aggregation problem in a single hop end-to-edge communication network.Firstly,to make sure all the end devices with various weights are fairly treated in data aggregation,a distributed end-to-edge cooperative scheme is proposed.Then,to handle the massive contention on the wireless channel caused by end devices,a multi-armed bandit(MAB)algorithm is designed to help the end devices find their most appropriate update rates.Diffe-rent from the traditional data aggregation works,combining the MAB enables our algorithm a higher efficiency in data aggregation.With a theoretical analysis,we show that the efficiency of our algorithm is asymptotically optimal.Comparative experiments with previous works are also conducted to show the strength of our algorithm.

Cross-linking Copolymerization of Acrylic Acid and Multi-armed Cross-linkers

The overall cross-linking copolymerization of acrylic acid and multi-armed cross-linkers are investigated by in situ interferometry. The results show that the more arms the cross-linkers have, the higher the polymerization rate is. However, they also mean the existence of less cross-linking efficiency and some defects in gel network.

Strict greedy design paradigm applied to the stochastic multi-armed bandit problem

The process of making decisions is something humans do inherently and routinely,to the extent that it appears commonplace. However,in order to achieve good overall performance,decisions must take into account both the outcomes of past decisions and opportunities of future ones. Reinforcement learning,which is fundamental to sequential decision-making,consists of the following components: 1 A set of decisions epochs; 2 A set of environment states; 3 A set of available actions to transition states; 4 State-action dependent immediate rewards for each action.At each decision,the environment state provides the decision maker with a set of available actions from which to choose. As a result of selecting a particular action in the state,the environment generates an immediate reward for the decision maker and shifts to a different state and decision. The ultimate goal for the decision maker is to maximize the total reward after a sequence of time steps.This paper will focus on an archetypal example of reinforcement learning,the stochastic multi-armed bandit problem. After introducing the dilemma,I will briefly cover the most common methods used to solve it,namely the UCB and εn- greedy algorithms. I will also introduce my own greedy implementation,the strict-greedy algorithm,which more tightly follows the greedy pattern in algorithm design,and show that it runs comparably to the two accepted algorithms.

Training a Quantum Neural Network to Solve the Contextual Multi-Armed Bandit Problem

Artificial intelligence has permeated all aspects of our lives today. However, to make AI behave like real AI, the critical bottleneck lies in the speed of computing. Quantum computers employ the peculiar and unique properties of quantum states such as superposition, entanglement, and interference to process information in ways that classical computers cannot. As a new paradigm of computation, quantum computers are capable of performing tasks intractable for classical processors, thus providing a quantum leap in AI research and making the development of real AI a possibility. In this regard, quantum machine learning not only enhances the classical machine learning approach but more importantly it provides an avenue to explore new machine learning models that have no classical counterparts. The qubit-based quantum computers cannot naturally represent the continuous variables commonly used in machine learning, since the measurement outputs of qubit-based circuits are generally discrete. Therefore, a continuous-variable (CV) quantum architecture based on a photonic quantum computing model is selected for our study. In this work, we employ machine learning and optimization to create photonic quantum circuits that can solve the contextual multi-armed bandit problem, a problem in the domain of reinforcement learning, which demonstrates that quantum reinforcement learning algorithms can be learned by a quantum device.

Stochastic programming based multi-arm bandit offloading strategy for internet of things

In order to solve the high latency of traditional cloud computing and the processing capacity limitation of Internet of Things(IoT)users,Multi-access Edge Computing(MEC)migrates computing and storage capabilities from the remote data center to the edge of network,providing users with computation services quickly and directly.In this paper,we investigate the impact of the randomness caused by the movement of the IoT user on decision-making for offloading,where the connection between the IoT user and the MEC servers is uncertain.This uncertainty would be the main obstacle to assign the task accurately.Consequently,if the assigned task cannot match well with the real connection time,a migration(connection time is not enough to process)would be caused.In order to address the impact of this uncertainty,we formulate the offloading decision as an optimization problem considering the transmission,computation and migration.With the help of Stochastic Programming(SP),we use the posteriori recourse to compensate for inaccurate predictions.Meanwhile,in heterogeneous networks,considering multiple candidate MEC servers could be selected simultaneously due to overlapping,we also introduce the Multi-Arm Bandit(MAB)theory for MEC selection.The extensive simulations validate the improvement and effectiveness of the proposed SP-based Multi-arm bandit Method(SMM)for offloading in terms of reward,cost,energy consumption and delay.The results showthat SMMcan achieve about 20%improvement compared with the traditional offloading method that does not consider the randomness,and it also outperforms the existing SP/MAB based method for offloading.

腰果酚基阻燃高分子材料研究进展

随着全球环保意识的提高和国家碳达峰战略的提出,利用可再生生物基资源制备阻燃高分子材料受到广泛关注。腰果酚来源广泛、价格低廉,具有多个高活性反应基团,有望用于商业化制备阻燃高分子材料。本文综述了用于改性聚氯乙烯、不饱和聚酯和环氧树脂的腰果酚基阻燃添加剂的制备方法,同时对比分析了其性能。总结归纳了阻燃腰果酚基环氧树脂、阻燃腰果酚基苯并噁嗪、阻燃腰果酚基紫外光固化涂层、阻燃腰果酚基聚氨酯泡沫和阻燃腰果酚基酚醛泡沫的最新研究进展。指出制备综合性能优异的多功能阻燃腰果酚基高分子材料是未来研究的重点方向。

腰果酚改性酚醛树脂的合成及其模塑料的性能

资源化、环保化与低成本化是传统材料的重要发展方向,本文在硼酸的辅助下,采用腰果酚对酚醛树脂进行改性,探讨了腰果酚和硼酸的引入及其用量对树脂性能的影响,以改性树脂为基体制备了酚醛模塑料,并对其性能进行的测试。结果显示:腰果酚的引入和用量会显著影响树脂的性能,高的替代量使树脂软化点和热稳定性下降,在硼酸的辅助下,则能够实现对改性树脂性能的有效调控,并且以该改性树脂制备的模塑料显示出较好的韧性和热稳定性。

腰果酚基不饱和树脂在木材增强改性中的应用

人工林速生木材孔隙率较大,密度低,且具有渗透性,因此可通过化学浸渍将人工合成树脂浸渍到木材的内部,从而提升速生木材的抗吸水性、抗压强度等性能。本文用腰果酚合成不饱和树脂(UPR),并用于浸渍改性杨木、杉木、樟子松3种速生木材,效果最显著的是杉木,其平均密度从0.4g/cm^(3)提高到1.04g/cm^(3),抗压强度从30.1MPa提升到90.4MPa,吸水率由167.3%降至7.9%。用傅里叶变换红外光谱仪(FTIR)证实了其化学结构,用凝胶渗透色谱(GPC)检测合成树脂各阶段产物的分子量分布,便于预测其结构式。X射线光电子能谱仪(XPS)分析表明,UPR浸渍以材料渗透性由外到内呈递减趋势的横向渗透为主。热重分析(TGA)表明UPR提高了改性木材的热稳定性。通过扫描电子显微镜(SEM)观察可以明显看到木材内部孔洞被树脂填充并交联固化,因此3种速生木材的抗吸水性、抗压强度和热稳定性都得到了不同程度的提升。

Apo E基因multi-ARMS与PCR-RFLP分型法的比较研究

目的 :以聚合酶链反应—限制性酶切片段长度多态性(PCR -RFLP)方法作为参照 ,建立一种ApoE基因分型方法。方法 :以基因组DNA为模板 ,用PCR -RFLP法和等位基因特异性复合PCR方法(MultiplexAmplificationRefractoryMutationSystem,multi-ARMS)检测了75例个体的ApoE基因型。结果 :共检测出5种常见的ApoE基因型 :ε2/2 ,ε3/3 ,ε2/3,ε3/4 ,ε2/4。两种方法所得的结果完全一致。结论 :说明multi-ARMS方法快速简便、准确可靠 。

分析涂料中腰果酚的方法研究

采用热裂解气相色谱-质谱(Py-GC/MS)方法,利用微量涂料样品在惰性气氛中迅速加热裂解,生成的众多裂解产物在气相色谱系统中进行有效分离,使得具有特征性的裂解碎片被质谱准确鉴定,只需1 h即可对微量的涂料样品中含有的腰果酚进行定性。探究了分析涂料中腰果酚的实验条件,确定了450℃是相对合适的裂解温度。涂料样品经过最优条件下分析的总离子流量色谱图中的腰果酚在26.68min出峰,特征质荷比碎片明显,峰响应、峰形状、两峰之间的分离度都很好,可以很好地进行定性。并利用不同质量比的腰果酚样品建立标准曲线,进一步对涂料中的腰果酚含量进行了定量分析。

生物基水性油墨配方对油墨性能的影响

利用超声波一步法,在很短时间内(1 h)合成了丙烯酸腰果酚酯,将其与甲基丙烯酸甲酯(MMA)、丙烯酸(AA)和丙烯酸丁酯(BA)共聚,合成了作为水性油墨连接料的生物基腰果酚改性丙烯酸树脂,最后在树脂中添加助剂配置生物基水性油墨,测试油墨的细度、干燥速度、硬度和附着力,以分析助剂对油墨性能的影响规律。结果表明,颜料为0.29%,SiO 2为3.6%,偶联剂为1.44%,增稠剂为0.57%,pH为8~9时,制得的生物基水性油墨的细度为16μm,干燥速度为80.5 mm/30 s,铅笔硬度为5 H,附着力为2级,耐水性为4级。

腰果酚改性丙烯酸树脂的生物基油墨制备及其性能

以丙烯酸腰果酚酯、丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、丙烯酸(AA)为单体,偶氮二异丁腈(AIBN)为引发剂,通过乳液聚合,合成了腰果酚改性丙烯酸树脂并将其与颜料等混合制备了生物基水性油墨。通过单因素法和正交实验优化树脂配方工艺,利用FTIR、DSC、TG对树脂的结构与性能进行了表征,考察了水性油墨的性能。研究结果表明,树脂最佳制备工艺条件为:反应温度85℃,反应时间6 h,BA的含量为10 mmol,n_(MMA):n_(BA)为1.5:1~2:1,丙烯酸腰果酚酯含量为16 mmol,AA含量为70 mmol,引发剂含量为4 mmol。腰果酚改性丙烯酸树脂具有优异的成膜性,玻璃化转变温度为24.08℃,硬度可达5H,附着力为2级,所制备的水性油墨涂层铅笔硬度为5H,附着力为1级,耐水性等级为4级。

STUDY ON THE CARDANOL-ALDEHYDE CONDENSATION POLYMER CONTAINING BORON-NITROGEN COORDINATE BOND

Cardanol-aldehyde condensation polymer containing boron-nitrogen coordinate bond (CFBN) has been synthesized and characterized by IR, XPS, HPLC and DTA-TG. Its properties were also investigated. The results show that the coating film of CFBN has excellent physico-mechanical properties, good anticorrosive properties and stable at high temperature. (Author abstract) 8 Refs.

Impedance control of multi-arm space robot for the capture of non-cooperative targets

Robotic systems are expected to play an increasingly important role in future space activities. The robotic on-orbital service, whose key is the capturing technology, becomes a research hot spot in recent years. This paper studies the dynamics modeling and impedance control of a multi-arm free-flying space robotic system capturing a non-cooperative target. Firstly, a control-oriented dynamics model is essential in control algorithm design and code realization. Unlike a numerical algorithm, an analytical approach is suggested. Using a general and a quasi-coordinate Lagrangian formulation, the kinematics and dynamics equations are derived.Then, an impedance control algorithm is developed which allows coordinated control of the multiple manipulators to capture a target.Through enforcing a reference impedance, end-effectors behave like a mass-damper-spring system fixed in inertial space in reaction to any contact force between the capture hands and the target. Meanwhile, the position and the attitude of the base are maintained stably by using gas jet thrusters to work against the manipulators' reaction. Finally, a simulation by using a space robot with two manipulators and a free-floating non-cooperative target is illustrated to verify the effectiveness of the proposed method.

Recent Development of Cardanol Based Polymer Materials-A Review

Polymers from renewable resources are receiving tremendous attention due to the increasing concerns on the depletion of fossil oils and deteriorated environments.Cardanol,as an abundant and renewable chemical raw material,has been widely used for the production of renewable polymer materials via converting into various of chemical monomers with active functional groups.This comprehensive review deals with various aspects of cardanol as a starting material the preparing various polymer and polymer composites such as benzoxazine resins,phenolic resin,polyurethanes,epoxy resin,vinyl ester polymers,polyamide and cyanate ester resins.The assessment of the future prospects for the use of cardanol to synthesise novel and valuable renewable materials is presented.

Biobased Aromatic-Aliphatic Polyols from Cardanol by Photochemical Thiol-ene Reaction

Biobased aromatic-aliphatic polyols were previously synthesized from a thermal thiol-ene reaction of propoxylated cardanol with 2-mercaptoethanol(ME)in the presence of azobisisobutyronitrile(AIBN)as a radical initiator.Cardanol used for this purpose was obtained as a dark-brown liquid(Gardner Color Reference^18).The photochemical thiol-ene reaction can also be used to prepare aromatic-aliphatic polyols by employing cardanol.Via the photochemical thiol-ene reaction,2-mercaptoethanol was added successfully to C=C double bond of cardanol,suggesting that phenolic group may not play an inhibitory role in the radical thiol-ene reaction.However,we preferred to alkoxylate the phenolic hydroxyl group of cardanol,which is much more reactive with isocyanates than phenolic hydroxyls,to generate a new aliphatic hydroxyl group.Furthermore,the functionality of polyols was also improved by two methods:1)using 1-thio-glycerol instead of 2-mercaptoethanol and 2)using alkoxylated cardanol with glycidol(Cardanol-GLY)instead of propoxylated cardanol(Cardanol-PO).These polyols were then used in preparation of rigid polyurethane foams that can be useful in various applications such as insulation of freezers,pipes and storage tanks in food and chemical industries.

Synthesis of Cardanol Sulfonate Gemini Surfactant and Enthalpy-Entropy Compensation of Micellization in Aqueous Solutions

A novel cardanol sulfonate Gemini surfactant with high surface properties was synthesized by cashew phenol, 1,3-dibromopropane and chlorosulfonic acid through three steps procedure of etherification, sulfonation and neutralization. A surface tension method was employed to investigate the thermo-dynamic properties of micellization in aqueous solution for cardanol sulfonate Gemini surfactant synthesized in laboratory. As a result, the micellization of cardanol sulfonate Gemini surfactant in aqueous solutions is spontaneous and entropy-driven. The micellization process is enthalpy-entropy compensated with the compensation temperature (Tc) of 308 ± 1 K.

Biobased Aromatic-Aliphatic Polyols by Thiol-Ene Reactions of Propoxylated Mercaptanized Cardanol

Aromatic-aliphatic polyols were obtained previously from the thiol-ene reactions of propoxylated cardanol with hydroxyalkyl mercaptans;these aromatic-aliphatic polyols were then utilized in the preparation of rigid polyurethane foams with excellent properties.The current work describes a variant of cardanol polyol synthesis by thiol-ene reactions in three steps.The first step is propoxylation of cardanol by reacting cardanol with propylene oxide;the second step is mercaptanization of propoxylated cardanol by reacting double bonds with hydrogen sulfide;and the third step involves the addition of the thiol groups of mercaptanized propoxylated cardanol to the double bonds of allyl alcohol,glycerol-1-allyl ether,and trimethylolpropane allyl ether.Thus,obtained polyols were characterized by standard analytical methods.Rigid polyurethane foams prepared from these polyols show promising physical-mechanical properties.The rigid polyurethane foams can be used for various applications such as thermo-insulation of freezers,storage tanks and pipes for food and chemical industries,wood substitutes and flotation materials.

Synthesis and Characterization of UV Oligomer based on Cardanol

In the present research,cardanol based di-acrylic UV oligomer was synthesized by thiol-ene coupling followed by ring opening reaction with glycidyl methacrylate.The intermediate as well as final diacrylate materials were analyzed by chemical as well as spectroscopic analysis.Further,ultraviolet(UV)radiation curable formulations were prepared by replacing commercial epoxy acrylate with synthesized UV oligomer in 10-50 wt%and applied on wood panels.The coated films were then evaluated for their optical,mechanical,chemical and thermal properties.Studies showed that up to 30 wt%amount of UVoligomer the coatings exhibited at par mechanical and chemical properties.The stain resistance of all the coatings was observed to be excellent.