基于节点网络模型的缝洞型碳酸盐岩油藏动态描述技术

缝洞型碳酸盐岩油藏非均质性极强,缝洞体离散分布,基于地球物理雕刻技术的静态描述存在较大不确定性。动态描述技术利用动态资料深化油藏认识,是动静结合提高油藏描述精度的重要途径。现有动态描述技术多基于连续介质理论构建,很难反映缝洞体离散分布的特征,与地球物理雕刻结果"兼容性"较差。针对缝洞体离散分布的特征,创建一种基于节点网络模型的动态描述技术。首先,提出基于节点网络的离散缝洞表征方法,建立节点网络模型自动生成方法,实现地球物理雕刻模型与节点网络模型快速转换;其次,基于节点网络模型,建立流动表征及开发指标计算方法,算例显示,产量、压力等开发指标计算结果吻合度超过93%,计算速度提升156倍;最后,形成缝洞关键特征参数反演方法,明确缝洞型油藏3个Ⅰ类、4个Ⅱ类共7个关键特征参数,基于拉丁超立方抽样建立辅助历史拟合方法,确定缝洞关键特征参数概率分布,算例显示,缝洞体储量、水体体积、断裂渗透率等反演误差约为10%,满足动态分析需求。该技术在塔河油田多个单元(井区)进行验证及应用,开发指标历史拟合符合率达90%以上,实现了缝洞体地质储量及动用程度的量化表征,提高了开发措施实施的针对性和有效性。

基于P-范式模型的P2P网络分组查询算法

P2P系统的可用性取决于查找数据的有效方法。利用节点兴趣和节点与中心节点的通信延迟建立链接,动态分组P2P网络的节点,查询节点通过中心节点转发搜索请求给其他中心节点,中心节点收到搜索请求后,若查找资源的主题排在本组关注的前K(K一般取1～3)位,则搜索本组内所有节点。在此基础上,提出了一种基于P-范式模型的P2P网络分组查询算法。算法分析和实验结果表明该算法的性能优于MSW查询算法。

单列高速列车运行仿真模型与算法

根据高速铁路线路特性,构建线路的3层节点网络模型。第1层描述车站和区间,第2层描述车站中心点、车站与区间的分界点和线路限速变化点及连接这些点的线路,第3层描述线路实际属性变化点及连接这些点的线路。鉴于高速动车组具有动力分散、质量均衡分布的特点,将动车组视为质量均匀且具有动力的绳体,创建高速动车组绳体模型。以动车组通过变坡点和变曲率点为例,分析动车组的受力状态,推导出对应的列车加速度计算公式。提出一种基于预推演的高速列车运行仿真算法。依据建立的线路模型、列车模型和仿真算法,开发了单列高速列车运行仿真系统。通过实例仿真验证了仿真模型与算法的准确性和实用性。

一种恶意软件传播的离散概率模型

复杂网络理论为恶意软件传播的研究提供了新的思路和方法.本文针对恶意软件的实际传播机制,提出一种新的离散概率DP-SI模型,该模型可适用于任意网络拓扑.同时提出了一种节点信息网络模型方法,为大规模复杂网络及复杂网络上的传播动力学的仿真,以及离散传播动力学模型的建立,提供了有效的研究平台.仿真结果表明本模型比传统模型更接近现实,对恶意软件的控制具有一定指导意义.

基于烟羽模型法对开放式小区的宏观评价

建设开放式小区,推行社区"街区化"成为社会各界关注的热点问题,有策略地将小区开放能够缓解社区周围道路的交通压力,优化城市路网结构。然而,现阶段研究大多致力于讨论开放型小区的优点,对某类型小区是否适宜开放的研究不足,为了解决这一问题,通过考虑如小区内部结构、内部道路网总里程、小区位置、周围路况等小区规模参数,基于烟羽模型法从宏观层面评价了不同规模的小区开放后对周围道路交通的影响程度。结果表明,在推进"街区化"的进程中,优先开放大规模社区对周围道路交通状况具有更大的影响。

节点数加速增长的复杂网络生长模型

受某些实际网络节点数按几何级数增长现象的启发,构造了每个时间步中按当前网络规模成比例地同时加入多个节点的节点数加速增长的网络模型.研究表明,在增长率不是很大的情况下网络度分布仍然是幂律的,但在不同的增长率r下幂律指数是不同的.得到了幂律指数介于2到3之间可调的无标度网络模型,并解析地给出了幂律指数随增长率变化的函数关系.数值模拟还显示,网络的平均最短距离随r减小而簇系数随r增大.

钢铁企业电力节点网络的研究和应用

对甘特(GANTT)图和网络图做了比较和分析,并提出了能量流网络的概念,建立了钢铁企业电力为节点的能量流网络物理模型。根据钢铁企业能源利用现状,分析了钢铁联合企业余热余能回收利用情况,提出了几种较为成熟的余热发电技术方案并阐述其发电原理和特点,从经济性上数据讨论其节能的效果。

基于故障影响域和预想集的变电站综合诊断方法研究

由于智能变电站各个智能电子设备(IED)之间广泛采用光纤进行通信,根据变电站的层次结构和物理连接,建立了变电站物理链路网络节点模型,从该模型出发建立变电站虚实回路信息映射模型。根据链路各个故障环节的影响域不同,通过对告警信息的分析引入故障预想集,建立故障概率和故障影响域准确度两个指标进行故障集的评判,最终确定故障环节。以变电站结构和间隔告警信息为算例证实了该方法能够有效地进行变电站物理链路层的故障定位。

A Composite Service Provision Method Based on Novel Node Model in Mobile Ad Hoc Networks

Composite service provision in mobile ad hoc networks encounters great challenges and its success rate is not satisfactory because the nodes' locations are dynamic and the nodes maybe unavailable at any time.Composite service is built through the service composition.In mobile ad hoc networks,the factors influencing the success rate of service composition are mainly the number of nodes and the time spent for the composition.The node's failure probability is proportional to the length of time the node exist in the networks.In order to improve the success rate of service composition,we take several measures.First,we split the service requirement into several segments and cluster the nodes,so that the nodes' waiting time for service composition can be reduced.Second,we propose a new node model of "one node contains multiple services" in mobile ad hoc networks.Using this type of nodes model,the number of nodes required for service composition can be reduced.These means can increase the success rate of service composition.

An Iterative Clustering-Based Localization Algorithm for Wireless Sensor Networks

In wireless sensor networks,node localization is a fundamental middleware service.In this paper,a robust and accurate localization algorithm is proposed,which uses a novel iterative clustering model to obtain the most representative intersection points between every two circles and use them to estimate the position of unknown nodes.Simulation results demonstrate that the proposed algorithm outperforms other localization schemes (such as Min-Max,etc.) in accuracy,scalability and gross error tolerance.

Modeling and Robustness of Knowledge Network in Supply Chain

The growth and evolution of the knowledge network in supply chain can be characterized by dynamic growth clustering and non-homogeneous degree distribution.The networks with the above characteristics are also known as scale-free networks.In this paper,the knowledge network model in supply chain is established,in which the preferential attachment mechanism based on the node strength is adopted to simulate the growth and evolution of the network.The nodes in the network have a certain preference in the choice of a knowledge partner.On the basis of the network model,the robustness of the three network models based on different preferential attachment strategies is investigated.The robustness is also referred to as tolerances when the nodes are subjected to random destruction and malicious damage.The simulation results of this study show that the improved network has higher connectivity and stability.

Node scattering manipulation based on trajectory model in wireless sensor network

To deploy sensor nodes over the area of interest,a scheme,named node scattering manipulation,was proposed.It adopted the following method:during node scattering,the initial states of every node,including the velocity and direction,were manipulated so that it would land in a region with a certain probability;every sensor was relocated in order to improve the coverage and connectivity.Simultaneously,to easily analyze the process of scattering sensors,a trajectory model was also proposed.Integrating node scattering manipulation with trajectory model,the node deployment in wireless sensor network was thoroughly renovated,that is,this scheme can scatter sensors.In practice,the scheme was operable compared with the previous achievements.The simulation results demonstrate the superiority and feasibility of the scheme,and also show that the energy consumption for sensors relocation is reduced.

Bidirectional Clone Node Model of Optimizing Performance of Structured P2P Overlay Network

In order to reduce the maintenance cost of structured Peer-to-Peer (P2P),Clone Node Protocol (CNP) based on user behavior is proposed.CNP considers the regularity of user behavior and uses the method of clone node.A Bidirectional Clone Node Chord model (BCNChord) based on CNP protocol is designed and realized.In BCNChord,Anticlockwise Searching Algorithm,Difference Push Synchronize Algorithm and Optimal Maintenance Algorithm are put forward to increase the performances.In experiments,according to the frequency of nodes,the maintenance cost of BCNChord can be 3.5%～32.5% lower than that of Chord.In the network of 212 nodes,the logic path hop is steady at 6,which is much more prior to 12 of Chord and 10 of CNChord.Theoretical analysis and experimental results show that BCNChord can effectively reduce the maintenance cost of its structure and simultaneously improve the query efficiency up to (1/4)O(logN).BCNChord is more suitable for highly dynamic environment and higher real-time system.

A Weighted Evolving Network with Community Size Preferential Attachment

Community structure is an important characteristic in real complex network.It is a network consists ofgroups of nodes within which links are dense but among which links are sparse.In this paper, the evolving network includenode, link and community growth and we apply the community size preferential attachment and strength preferentialattachment to a growing weighted network model and utilize weight assigning mechanism from BBV model.Theresulting network reflects the intrinsic community structure with generalized power-law distributions of nodes'degreesand strengths.

The impact of hidden node on model of ad hoc network

To deal with hidden nodes in ad hoc network, we take throughput as the metric to evaluate the performance of network. Firstly, we modeled the MAC layer of ad hoc network based on 802.11 DCF without the existence of hidden nodes. By means of the proposed model, we evaluated the throughput performance of DCF in multi-hop wireless networks. Secondly, we performed simulations to validate this model. The outcome of comparison is that there exists much difference in throughput between the model and the simulation. For reducing this difference, we modified the model by involving hidden nodes under the condition that the AODV route protocol was chosen, and analytically analyzed the influence of hidden nodes on theoretical throughput. At last, we validated the accuracy of this model by comparing the analytical results with simulation results.

Available capacity and robust wireless mesh connectivity of TDD-based networks

This paper addresses the available capacity and robust connectivity of time division duplex based wireless mesh networks （TDD-based WMNs）. A stochastic model is presented for TDD-based WMNs. Considering the parameters that affect the network performance like ratio of control slots number to data slots number, collision probability, node density and average hopcounts, the availa- ble capacity for each node is inferred. Meanwhile, the order of transmission range for robust connec- tivity of large scale WMNs is derived. With the stochastic model and inferred available capacity per node, the performance of TDD-based WMNs using IEEE 802.16 standard is analyzed under various conditions. Simulation results indicate that the available capacity of IEEE 802.16-based TDD-based WMNs and the theoretical result have the same increasing and decreasing trend as the node density increases. Simulation results also illustrate the optimal value of the ratio of control slots number to data slots number that maximizes the available capacity.

Impact of Heterogeneity on Forwarding Schemes in Opportunistic Networks

In the paper, we concentrate on the infl uence of heterogeneity on the performance of forwarding algorithms under opportunistic networks. Therefore, we first describe two different heterogeneous network models, and capture the heterogeneity which concern mobile nodes' contact dynamics under the individual models and the spatial models. Then we investigate inter-contact time is not fully follow exponential distribution and compare the performance of the delivery delay between direct forwarding protocol and three-hop forwarding protocol under three network models. We illustrate the performance of message delivery delay under the spray and wait protocol and prophet protocol from simulation results. Our simulation results show that the heterogeneity should be considered for the performance of forwarding protocols.

A KAD Network Evolution Model Based on Node Behavior

An evolution model of KAD Dynamic Model Network(KDMN) is proposed to study the reason of hot node and simulate the process of network evolution based on node behavior from a holistic perspective.First,some symbols and meanings are introduced to describe nodes relationship and network states at a time step.Second,some evolution rules for network are formulated when node behaviors of join,exit,routing table update,data retrieval and content index distribution happen with different contextual scene in KAD network.In addition,a lightweight simulator is designed to implement the KDMN model.Moreover,an example of how to use the simulator to simulate the network changes in order to observe the result is described in detail.Finally,the KDMN is applied to analyze the reason for the formation of hot nodes in the BT and eMule network in the experiment.The different evolution principles of local priority,global priority and hybrid random are adopted based on the provision of network protocol of BT and eMule.The result of this experiment demonstrates that there are some hot nodes exist in the KAD network.However,the principle of hybrid random can effectively alleviate the phenomenon that a node is widely linked with others compared with global and local priority.

INCENTIVE MECHANISMS FOR TRUSTWORTHY ROUTING BASED ON GAME MODEL OF THE STRATEGIES OF NODES IN P2P NETWORKS

The trustworthiness and security of routing in the existing Peer-to-Peer (P2P) networks can not be ensured because of the diversity of the strategies of P2P nodes. This paper firstly uses game theory to establish game model of the strategies and profits of various types of routing nodes. Then,two incentive mechanisms for the corresponding stages of P2P trustworthy routing are proposed,namely trust associated mechanism and trust compensated mechanism. Simulation results show that the incentive mechanisms proposed in this paper will encourage cooperation actions of good nodes and restrain malicious actions of bad nodes,which ensure the trustworthiness of routing consequently.

Topological Properties of Complex Networks with Different Types of Nodes

Nodes play different roles or have different functions in many natural and social networks.In this paper,a simple model with different types of nodes and deterministic selective linking rule is proposed.The structural properties by theoretical predictions are investigated that the given model exhibits a power-law distribution.