The service recommendation mechanism as a key enabling technology that provides users with more proactive and personalized service is one of the important research topics in mobile social network (MSN). Meanwhile, M...The service recommendation mechanism as a key enabling technology that provides users with more proactive and personalized service is one of the important research topics in mobile social network (MSN). Meanwhile, MSN is susceptible to various types of anonymous information or hacker actions. Trust can reduce the risk of interaction with unknown entities and prevent malicious attacks. In our paper, we present a trust-based service recommendation algorithm in MSN that considers users' similarity and friends' familiarity when computing trustworthy neighbors of target users. Firstly, we use the context information and the number of co-rated items to define users' similarity. Then, motivated by the theory of six degrees of space, the friend familiarity is derived by graph-based method. Thus the proposed methods are further enhanced by considering users' context in the recommendation phase. Finally, a set of simulations are conducted to evaluate the accuracy of the algorithm. The results show that the friend familiarity and user similarity can effectively improve the recommendation performance, and the friend familiarity contributes more than the user similarity.展开更多
Opportunistic networking-forwarding messages in a disconnected mobile ad hoc network via any encountered nodes offers a new mechanism for exploiting the mobile devices that many users already carry. However, forwardin...Opportunistic networking-forwarding messages in a disconnected mobile ad hoc network via any encountered nodes offers a new mechanism for exploiting the mobile devices that many users already carry. However, forwarding messages in such a network is trapped by many particular challenges, and some protocols have contributed to solve them partly. In this paper, we propose a Context-Aware Adaptive opportunistic Routing algorithm(CAAR). The algorithm firstly predicts the approximate location and orientation of the destination node by using its movement key positions and historical communication records, and then calculates the best neighbor for the next hop by using location and velocity of neighbors. In the unpredictable cases, forwarding messages will be delivered to the more capable forwarding nodes or wait for another transmission while the capable node does not exist in the neighborhood. The proposed algorithm takes the movement pattern into consideration and can adapt different network topologies and movements. The experiment results show that the proposed routing algorithm outperforms the epidemic forwarding(EF) and the prophet forwarding(PF) in packet delivery ratio while ensuring low bandwidth overhead.展开更多
In the current society, based on the growing development of network information technology, the teaching in many colleges and universities has also introduced it to adapt to the situation. This trend can provide more ...In the current society, based on the growing development of network information technology, the teaching in many colleges and universities has also introduced it to adapt to the situation. This trend can provide more useful conditions for students to learn, which requires students to master enough self-learning abilities to adapt to this model. The study in the paper shows that students are usually interested in autonomous learning in a multimodal environment, but the degree of strategy choice is relatively low, and the learning process is blind and passive with the lack of self-confidence. Facing the future, schools should actively integrate into network thinking, and teachers should change their roles and train and guide students’ learning strategies and learning motivations, so as to achieve better teaching results.展开更多
Using the Wireless Sensor Networks WSNs in a wide variety of applications is currently considered one of the most challenging solutions. For instance, this technology has evolved the agriculture field, with the precis...Using the Wireless Sensor Networks WSNs in a wide variety of applications is currently considered one of the most challenging solutions. For instance, this technology has evolved the agriculture field, with the precision agriculture challenge. In fact, the cost of sensors and communication infrastructure continuously trend down as long as the technological advances. So, more growers dare to implement WSN for their crops. This technology has drawn substantial interests by improving agriculture productivity. The idea consists of deploying a number of sensors in a given agricultural parcel in order to monitor the land and crop conditions. These readings help the farmer to make the right inputs at the right moment. In this paper, we propose a complete solution for gathering different type of data from variable fields of a large agricultural parcel. In fact, with the in-field variability, adopting a unique data gathering solution for all kinds of fields reveals an inconvenient approach. Besides, as a fault-tolerant application, precision agriculture does not require a high precision value of sensed data. So, our approach deals with a context aware data gathering strategy. In other words, depending on a defined context for the monitored field, the data collector will decide the data gathering strategy to follow. We prove that this approach improves considerably the lifetime of the application.展开更多
Language is an indispensable element in the constitution of human cognition. Rhetorical language, parody, as a kind of linguistic phenomena and a communicative action, also demonstrates a cognitive process. With the d...Language is an indispensable element in the constitution of human cognition. Rhetorical language, parody, as a kind of linguistic phenomena and a communicative action, also demonstrates a cognitive process. With the detailed case study, this paper aims to probe into the cognitive process of a parody in the context of network media, including the the Construction Process and the Acceptance Process, in hope of exploring the acadamic research and education of parody.展开更多
The language used in the context of network media features variation, flexibility, and comprehensiveness, in which parody is one of the most employed devices. Modern cognitive science prefers to take parody as a cogni...The language used in the context of network media features variation, flexibility, and comprehensiveness, in which parody is one of the most employed devices. Modern cognitive science prefers to take parody as a cognitive act rather than a sheer linguistic modification act, which has provided a new prospective for further research about parody in the context of network media. This paper aims to probe into the cognitive constraints in the mechanism of parody in the context of network media, in hope to make a detailed explanation of the cognitive process of it and to strengthen the comprehension and appreciation of it.展开更多
Cooperative wireless sensor networks have drastically grown due to node co-opera- tive in unaltered environment. Various real time applications are developed and deployed under cooperative network, which controls and ...Cooperative wireless sensor networks have drastically grown due to node co-opera- tive in unaltered environment. Various real time applications are developed and deployed under cooperative network, which controls and coordinates the flow to and from the nodes to the base station. Though nodes are interlinked to give expected state behavior, it is vital to monitor the malicious activities in the network. There is a high end probability to compromise the node behavior that leads to catastrophes. To overcome this issue a Novel Context Aware-IDS approach named Context Aware Nodal Deployment-IDS (CAND-IDS) is framed. During data transmission based on node properties and behavior CAND-IDS detects and eliminates the malicious nodes in the explored path. Also during network deployment and enhancement, node has to follow Context Aware Cooperative Routing Protocol (CCRP), to ensure the reliability of the network. CAND-IDS are programmed and simulated using Network Simulator software and the performance is verified and evaluated. The simulation result shows significant improvements in the throughput, energy consumption and delay made when compared with the existing system.展开更多
跨境电商商品推荐不同于传统电商推荐,其“用户-商品”交互矩阵高度稀疏并且新用户/商品的占比很大,导致传统的协同过滤推荐模型很难满足平台和用户的要求。为了解决这些问题,并结合跨境电商的行业特点,提出了一种基于情境异质图神经网...跨境电商商品推荐不同于传统电商推荐,其“用户-商品”交互矩阵高度稀疏并且新用户/商品的占比很大,导致传统的协同过滤推荐模型很难满足平台和用户的要求。为了解决这些问题,并结合跨境电商的行业特点,提出了一种基于情境异质图神经网络的推荐模型(recommendation model based on contextual heterogeneous graph neural network,CHGNRM)。该模型具有两个显著的优势:(1)将通过变异系数法得到的情境权重纳入信息传播和聚合的过程中,提高个性化推荐的准确性;(2)构造“用户-商品-品类-店铺”四部图作为模型的输入,在异质图上通过图卷积神经网络(LightGCN)充分挖掘高阶邻居信息,提升推荐质量。CHGNRM在2019年安泰杯跨境电商智能算法大赛的初赛和复赛两个数据子集上进行应用,较12种基准推荐算法在HR@10、NDCG@10及MRR@10上分别平均提升了3.4%、4.2%和2.6%,这说明了所提模型是有效的。展开更多
As the number of Virtual Machines(VMs) consolidated on single physical server increases with the rapid advance of server hardware,virtual network turns complex and frangible.Modern Network Security Engines(NSE) are in...As the number of Virtual Machines(VMs) consolidated on single physical server increases with the rapid advance of server hardware,virtual network turns complex and frangible.Modern Network Security Engines(NSE) are introduced to eradicate the intrusions occurring in the virtual network.In this paper,we point out the inadequacy of the present live migration implementation,which hinders itself from providing transparent VM relocation between hypervisors equipped with Network Security Engines(NSE-H).This occurs because the current implementation ignores VM-related Security Context(SC) required by NSEs embedded in NSE-H.We present the CoM,a comprehensive live migration framework,for NSE-H-based virtualization computing environment.We built a prototype system on Xen hypervisors to evaluate our framework,and conduct experiments under various realistic application environments.The results demonstrate that our solution successfully fixes the inadequacy of the present live migration implementation,and the performance overhead is negligible.展开更多
为应对城市交通环境复杂及信号控制策略适应性差的问题,提出一种融合上下文感知状态空间、动态自适应奖励机制与启发式奖励塑形的多智能体深度强化学习信号控制方法。基于SUMO平台,将交叉口建模为独立智能体,利用改进的双深度Q网络DDQN(...为应对城市交通环境复杂及信号控制策略适应性差的问题,提出一种融合上下文感知状态空间、动态自适应奖励机制与启发式奖励塑形的多智能体深度强化学习信号控制方法。基于SUMO平台,将交叉口建模为独立智能体,利用改进的双深度Q网络DDQN(double deep Q-network)进行策略优化。设计考虑区域流量、方向流量不平衡与相位周期信息的上下文增强状态空间,并引入基于拥堵指数的动态奖励机制及启发式奖励塑形提升策略效率与适应性。仿真结果表明,与固定时序控制、最大压力控制、自组织信号控制、Soft Actor-Critic、StageLight以及标准DDQN这6种基准算法相比,所提出的方法在复杂交通环境中表现出更高的信号控制效率和更强的拥堵缓解能力,显著提高了整体交通运行效率,验证了其在复杂场景下的有效性与鲁棒性。展开更多
In opportunistic Networks,compromised nodes can attack social context-based routing protocols by publishing false social attributes information.To solve this problem,we propose a security scheme based on the identity-...In opportunistic Networks,compromised nodes can attack social context-based routing protocols by publishing false social attributes information.To solve this problem,we propose a security scheme based on the identity-based threshold signature which allows mobile nodes to jointly generate and distribute the secrets for social attributes in a totally self-organized way without the need of any centralized authority.New joining nodes can reconstruct their own social attribute signatures by getting enough partial signature services from encounter opportunities with the initial nodes.Mobile nodes need to testify whether the neighbors can provide valid attribute signatures for their routing advertisements in order to resist potential routing attacks.Simulation results show that:by implementing our security scheme,the network delivery probability of the social context-based routing protocol can be effectively improved when there are large numbers of compromised nodes in opportunistic networks.展开更多
基金Supported by the National Natural Science Foundation of China(71662014 and 61602219)the Natural Science Foundation of Jiangxi Province of China(20132BAB201050)the Science and Technology Project of Jiangxi Province Educational Department(GJJ151601)
摘要The service recommendation mechanism as a key enabling technology that provides users with more proactive and personalized service is one of the important research topics in mobile social network (MSN). Meanwhile, MSN is susceptible to various types of anonymous information or hacker actions. Trust can reduce the risk of interaction with unknown entities and prevent malicious attacks. In our paper, we present a trust-based service recommendation algorithm in MSN that considers users' similarity and friends' familiarity when computing trustworthy neighbors of target users. Firstly, we use the context information and the number of co-rated items to define users' similarity. Then, motivated by the theory of six degrees of space, the friend familiarity is derived by graph-based method. Thus the proposed methods are further enhanced by considering users' context in the recommendation phase. Finally, a set of simulations are conducted to evaluate the accuracy of the algorithm. The results show that the friend familiarity and user similarity can effectively improve the recommendation performance, and the friend familiarity contributes more than the user similarity.
基金Supported by the National Natural Science Foundation of China(61373040,61173137)the Ph.D.Programs Foundation of Ministry of Education of China(20120141110002)the Key Project of Natural Science Foundation of Hubei Province(2010CDA004)
摘要Opportunistic networking-forwarding messages in a disconnected mobile ad hoc network via any encountered nodes offers a new mechanism for exploiting the mobile devices that many users already carry. However, forwarding messages in such a network is trapped by many particular challenges, and some protocols have contributed to solve them partly. In this paper, we propose a Context-Aware Adaptive opportunistic Routing algorithm(CAAR). The algorithm firstly predicts the approximate location and orientation of the destination node by using its movement key positions and historical communication records, and then calculates the best neighbor for the next hop by using location and velocity of neighbors. In the unpredictable cases, forwarding messages will be delivered to the more capable forwarding nodes or wait for another transmission while the capable node does not exist in the neighborhood. The proposed algorithm takes the movement pattern into consideration and can adapt different network topologies and movements. The experiment results show that the proposed routing algorithm outperforms the epidemic forwarding(EF) and the prophet forwarding(PF) in packet delivery ratio while ensuring low bandwidth overhead.
摘要In the current society, based on the growing development of network information technology, the teaching in many colleges and universities has also introduced it to adapt to the situation. This trend can provide more useful conditions for students to learn, which requires students to master enough self-learning abilities to adapt to this model. The study in the paper shows that students are usually interested in autonomous learning in a multimodal environment, but the degree of strategy choice is relatively low, and the learning process is blind and passive with the lack of self-confidence. Facing the future, schools should actively integrate into network thinking, and teachers should change their roles and train and guide students’ learning strategies and learning motivations, so as to achieve better teaching results.
摘要Using the Wireless Sensor Networks WSNs in a wide variety of applications is currently considered one of the most challenging solutions. For instance, this technology has evolved the agriculture field, with the precision agriculture challenge. In fact, the cost of sensors and communication infrastructure continuously trend down as long as the technological advances. So, more growers dare to implement WSN for their crops. This technology has drawn substantial interests by improving agriculture productivity. The idea consists of deploying a number of sensors in a given agricultural parcel in order to monitor the land and crop conditions. These readings help the farmer to make the right inputs at the right moment. In this paper, we propose a complete solution for gathering different type of data from variable fields of a large agricultural parcel. In fact, with the in-field variability, adopting a unique data gathering solution for all kinds of fields reveals an inconvenient approach. Besides, as a fault-tolerant application, precision agriculture does not require a high precision value of sensed data. So, our approach deals with a context aware data gathering strategy. In other words, depending on a defined context for the monitored field, the data collector will decide the data gathering strategy to follow. We prove that this approach improves considerably the lifetime of the application.
摘要Language is an indispensable element in the constitution of human cognition. Rhetorical language, parody, as a kind of linguistic phenomena and a communicative action, also demonstrates a cognitive process. With the detailed case study, this paper aims to probe into the cognitive process of a parody in the context of network media, including the the Construction Process and the Acceptance Process, in hope of exploring the acadamic research and education of parody.
摘要The language used in the context of network media features variation, flexibility, and comprehensiveness, in which parody is one of the most employed devices. Modern cognitive science prefers to take parody as a cognitive act rather than a sheer linguistic modification act, which has provided a new prospective for further research about parody in the context of network media. This paper aims to probe into the cognitive constraints in the mechanism of parody in the context of network media, in hope to make a detailed explanation of the cognitive process of it and to strengthen the comprehension and appreciation of it.
摘要Cooperative wireless sensor networks have drastically grown due to node co-opera- tive in unaltered environment. Various real time applications are developed and deployed under cooperative network, which controls and coordinates the flow to and from the nodes to the base station. Though nodes are interlinked to give expected state behavior, it is vital to monitor the malicious activities in the network. There is a high end probability to compromise the node behavior that leads to catastrophes. To overcome this issue a Novel Context Aware-IDS approach named Context Aware Nodal Deployment-IDS (CAND-IDS) is framed. During data transmission based on node properties and behavior CAND-IDS detects and eliminates the malicious nodes in the explored path. Also during network deployment and enhancement, node has to follow Context Aware Cooperative Routing Protocol (CCRP), to ensure the reliability of the network. CAND-IDS are programmed and simulated using Network Simulator software and the performance is verified and evaluated. The simulation result shows significant improvements in the throughput, energy consumption and delay made when compared with the existing system.
摘要现有的基于深度学习的医学图像分割方法,大多是利用大量的训练数据拟合检测网络,以获得优异的检测性能。这些方法往往需要较大的模型参数,导致检测实时性较差。为此,提出了基于局部上下文引导特征深度融合轻量级医学分割网络(local context guided feature deep fusion lightweight medical segmentation network,LCGML-net)。LCGML-net通过精确的特征选择与特征融合来减少模型拟合所需的参数数量,从而在保证检测精度的同时实现更小的模型参数。在特征提取阶段和映射阶段,分别通过提取和融合目标的多层次多尺度局部上下文特征来丰富特征表达和精准分割。在STARE、CHASEDB1和KITS19等多个基准数据集上开展的实验证明,与其他方法相比,所提出的LCGML-net具有最佳的检测性能和最小的模型参数。
摘要跨境电商商品推荐不同于传统电商推荐,其“用户-商品”交互矩阵高度稀疏并且新用户/商品的占比很大,导致传统的协同过滤推荐模型很难满足平台和用户的要求。为了解决这些问题,并结合跨境电商的行业特点,提出了一种基于情境异质图神经网络的推荐模型(recommendation model based on contextual heterogeneous graph neural network,CHGNRM)。该模型具有两个显著的优势:(1)将通过变异系数法得到的情境权重纳入信息传播和聚合的过程中,提高个性化推荐的准确性;(2)构造“用户-商品-品类-店铺”四部图作为模型的输入,在异质图上通过图卷积神经网络(LightGCN)充分挖掘高阶邻居信息,提升推荐质量。CHGNRM在2019年安泰杯跨境电商智能算法大赛的初赛和复赛两个数据子集上进行应用,较12种基准推荐算法在HR@10、NDCG@10及MRR@10上分别平均提升了3.4%、4.2%和2.6%,这说明了所提模型是有效的。
摘要图属性预测任务因其在多个科学学科中具有变革性的潜力而受到广泛关注,其中分子属性预测是该任务的一个重要实例。传统上,一个分子可以表示为图结构形式或SMILES(simplified molecular-input line-entry system)文本形式的数据,本质上均可视为带有结构与语义信息的图表示。近年来,大语言模型(large language models,LLMs)的快速发展使自然语言处理(natural language processing,NLP)领域发生了革命性的变化。尽管利用LLMs来辅助理解由SMILES所表示的结构化图数据是较为自然的思路,但LLMs将如何影响分子属性预测任务的探索仍处于早期阶段。在这项工作中,本文通过2个视角来推进这一目标:少样本(Few-shot)分子分类,以及使用LLMs为分子生成的全新富文本解释作为分子的表示。具体来说,本文首先基于LLMs的情境学习能力(in-context learning,ICL)来提示LLMs进行Few-shot分子分类,并评估其性能。之后,利用LLMs丰富的世界知识,为原始SMILES文本生成语义丰富的解释,利用该解释作为分子的表示,在多个分子属性预测下游任务上微调小规模语言模型来完成最终的预测。实验结果表明:Few-shot分子分类可以利用较少的示例获得不错的分类性能,且将文本解释作为分子的新表示的方法在多个评测数据集上超越了基准方法。此外,本文为LLMs生成的富文本表示何时能够赋能分子属性预测任务提供了理论上的见解。研究证实了LLMs在分子属性预测任务上具备巨大潜力。
基金supported by State Key Laboratory of Software Development Environment under Grant No. SKLSDE-2009ZX-02China Aviation Science Fund under Grant No.20081951National High Technical Research and Development Program of China (863 Program) under Grant No.2007AA01Z183
摘要As the number of Virtual Machines(VMs) consolidated on single physical server increases with the rapid advance of server hardware,virtual network turns complex and frangible.Modern Network Security Engines(NSE) are introduced to eradicate the intrusions occurring in the virtual network.In this paper,we point out the inadequacy of the present live migration implementation,which hinders itself from providing transparent VM relocation between hypervisors equipped with Network Security Engines(NSE-H).This occurs because the current implementation ignores VM-related Security Context(SC) required by NSEs embedded in NSE-H.We present the CoM,a comprehensive live migration framework,for NSE-H-based virtualization computing environment.We built a prototype system on Xen hypervisors to evaluate our framework,and conduct experiments under various realistic application environments.The results demonstrate that our solution successfully fixes the inadequacy of the present live migration implementation,and the performance overhead is negligible.
摘要为应对城市交通环境复杂及信号控制策略适应性差的问题,提出一种融合上下文感知状态空间、动态自适应奖励机制与启发式奖励塑形的多智能体深度强化学习信号控制方法。基于SUMO平台,将交叉口建模为独立智能体,利用改进的双深度Q网络DDQN(double deep Q-network)进行策略优化。设计考虑区域流量、方向流量不平衡与相位周期信息的上下文增强状态空间,并引入基于拥堵指数的动态奖励机制及启发式奖励塑形提升策略效率与适应性。仿真结果表明,与固定时序控制、最大压力控制、自组织信号控制、Soft Actor-Critic、StageLight以及标准DDQN这6种基准算法相比,所提出的方法在复杂交通环境中表现出更高的信号控制效率和更强的拥堵缓解能力,显著提高了整体交通运行效率,验证了其在复杂场景下的有效性与鲁棒性。
基金the Major national S&T program under Grant No. 2011ZX03005-002National Natural Science Foundation of China under Grant No. 60872041,61072066the Fundamental Research Funds for the Central Universities under Grant No. JY10000903001,JY10000901034
摘要In opportunistic Networks,compromised nodes can attack social context-based routing protocols by publishing false social attributes information.To solve this problem,we propose a security scheme based on the identity-based threshold signature which allows mobile nodes to jointly generate and distribute the secrets for social attributes in a totally self-organized way without the need of any centralized authority.New joining nodes can reconstruct their own social attribute signatures by getting enough partial signature services from encounter opportunities with the initial nodes.Mobile nodes need to testify whether the neighbors can provide valid attribute signatures for their routing advertisements in order to resist potential routing attacks.Simulation results show that:by implementing our security scheme,the network delivery probability of the social context-based routing protocol can be effectively improved when there are large numbers of compromised nodes in opportunistic networks.