运用多层网路模型估算基于组件开发模型的信息系统工程的开发规模

本文介绍网路模型的基本概念、基本性质、模型的建立规则、规模点数(spc)的分层分析及计算方法,并对该模型的意义及有效性进行论述。最后,本文还介绍多层网路模型实施的具体步骤。

基于贝叶斯网络模型的中老年缺血性脑卒中患者社会功能的影响因素分析

目的 探讨中老年缺血性脑卒中患者社会功能的影响因素及因素间的网络关系。方法 2022年8月~2023年3月选取华北理工大学附属医院住院治疗的中老年缺血性脑卒中550名患者为研究对象,通过问卷调查和查阅病例收集资料。采用卡方检验、多因素logistic回归分析模型进行变量的初步筛选,采用“bnlearn”贝叶斯网络软件包进行模型构建,Netica软件进行模型推理。结果 多因素logistic回归分析结果显示,日常生活活动能力依赖他人(OR=3.702,95%CI:2.440~5.619);慢性病资源利用不理想(OR=2.791,95%CI:1.835~4.247)是社会功能危险因素。贝叶斯网络模型显示,社会关系和家庭支持通过慢性病资源利用、日常生活活动能力及伤残接受度与社会功能间接相关。结论 中老年缺血性脑卒中患者社会功能障碍发生率较高,对低水平社会关系、家庭支持、伤残接受度及日常生活活动能力依赖他人、慢性病资源利用不理想的患者应加强健康教育,减少其社会功能障碍的发生。

应急交通疏散路径的网络模型

突发事件的不可预测性和随机性对公共安全提出了巨大的挑战,尤其对于突发事件下城市应急交通的疏散提出了更高的要求。为了寻求最佳的应急交通疏散路径,主要讨论了在已知停车场现存车数、车站疏散人数以及避难所容量的相关数据的基础上,如何把该问题转化成最小费用最大流的网络模型了方法,并用实例进行了验证,旨在为应急交通组织提供科学决策的依据。

基于神经网络算法的无线网络安全模型研究

信息技术的快速发展使得信息安全问题愈发严峻,无线网络的广泛应用使得无线网络遭受到的安全威胁类型复杂多样。采用PCA和BP神经网络建立了无线网络安全模型,分析了无线网络安全问题。通过对无线网络传输数据的主成分分析,将获得的主成分分量作为BP神经网络的训练数据进行网络训练,获得攻击类型检测的网络安全模型。结果表明,PCA和BP网络用于无线网络攻击类型检测中识别率提高,误报率降低,对提升无线网络安全性具有一定的参考价值。

基于无线传感网与移动通信网的网络融合模型

为了实现无线传感器网络与移动通信网络之间的无缝融合的目的,同时作为研究感知系统设计测试一体化平台的基础,采用以传统网络融合策略为基础,结合无线传感网和移动通信网自身的特点,并加入QoS保证和安全机制的方法,提出了融合模型。通过实现验证了模型的可用性并提出了下一步的研究方向。

Optimal path finding algorithms based on SLSD road network model

A solution to compute the optimal path based on a single-line-single-directional（SLSD）road network model is proposed.Unlike the traditional road network model,in the SLSD conceptual model,being single-directional and single-line style,a road is no longer a linkage of road nodes but abstracted as a network node.Similarly,a road node is abstracted as the linkage of two ordered single-directional roads.This model can describe turn restrictions,circular roads,and other real scenarios usually described using a super-graph.Then a computing framework for optimal path finding（OPF）is presented.It is proved that classical Dijkstra and A algorithms can be directly used for OPF computing of any real-world road networks by transferring a super-graph to an SLSD network.Finally,using Singapore road network data,the proposed conceptual model and its corresponding optimal path finding algorithms are validated using a two-step optimal path finding algorithm with a pre-computing strategy based on the SLSD road network.

Optimization method for evacuation zone with network reconfiguration based on dynamic simulation

Abstract： With a determinate danger zone and evacuation demand caused by an emergency, an optimization method for the evacuation zone with network reconfiguration based on dynamic simulation is proposed. The method contains three modules. First, the network in the evacuation zone is optimized by a model with the integrated strategy of lane reversal and intersection conflict elimination. Secondly, the dynamic evacuation simulation model based on the cell transmission model is applied to simulate the dynamic propagation process of evacuated vehicles in the network in the evacuation zone. The evacuation time for all evacuated vehicles leaving the danger zone is obtained and the setting of the current evacuation zone is fed back. Thirdly, the arrival distributions of evacuated vehicles at critical intersections of the evacuation zone are also obtained to estimate the delay at critical intersection to determine whether the intersection should be taken as the critical intersection in the next iteration. The evacuation zone is expanded gradually through iteration, and the reasonable evacuation zone and the optimal evacuation network is confirmed. Based on the survey of the parking lot and urban street network around Nanjing Olympic Sports Center, the models and the iterative algorithm were applied to obtain the optimal plan of the evacuation zone with network reconfiguration in an evacuation situation to verify the validity of the proposed method.

Fast Analysis of Power/Ground Networks via Circuit Reduction

This paper presents an efficient algorithm for reducing RLC power/ground network complexities by exploitation of the regularities in the power/ground networks. The new method first builds the equivalent models for many series RLC-current chains based on their Norton＇s form companion models in the original networks,and then the precondition conjugate gradient based iterative method is used to solve the reduced networks,which are symmetric positive definite. The solutions of the original networks are then back solved from those of the reduced networks.Experimental results show that the complexities of reduced networks are typically significantly smaller than those of the original circuits, which makes the new algorithm extremely fast. For instance, power/ground networks with more than one million branches can be solved in a few minutes on modern Sun workstations.

基于字符和单词表示的哈萨克语词性标注研究

自然语言处理任务中词性标注是基础性的工作,其可以应用到后续各种NLP任务中。在神经网络自然语言处理任务中多使用分布式词表示,获取单词的语义和语法信息,并取得了非常明显的效果。对于像哈萨克语这样形态丰富的语言,在词性标注时,单词内部的各种信息非常有用。在文章中,我们构建了基础的哈萨克语词性标注语料库,并采用基于字符并联合单词信息,提出一种有效的哈萨克语词标注模型。使用这一方法,避免了传统机器学习方法中手工构建特征的问题,在新疆日报哈文版构建的语料库上,准确率达到了61.40%。为进一步提升性能提供了很好的参考。

孔隙尺度下油驱水岩石电阻率性质研究

理论模拟是研究孔隙尺度下油驱水岩石电性的一种重要手段之一。以wang建立的网路模型为基础,分析了润湿性、孔隙拓扑特征、孔隙几何形状以及水膜厚度等对岩石电性的影响,同时对四块亲水砂岩岩样进行油驱水电阻率响应数值模拟,并将实验结果与理论模拟的结果进行对比分析。结果表明:对于亲水岩石油驱水情况下,在高含水饱和度时,电阻率增大系数与含水饱和度在对数坐标下呈现一种线性关系,然而在低含水饱和度下,曲线显示凸状,表明低含水饱和度下饱和度指数n值变小。水膜厚度越大,n值越小;孔隙连通性越好,即配位数越大,n值越小;在含水饱和度较低时,孔喉半径越小,n值越大;在含水饱和度较高时,孔隙几何形状对岩石电性影响不是很明显。在高含水饱和度下,岩电实验的结果与理论结果十分吻合,在低含水饱和度下,理论模拟的结果由于受实验限制未被证实,在电阻率增大系数与含水饱和度关系图上显示凸状。

基于CMAC和PID算法的发动机导流叶片控制系统

针对某型发动机数字调节器导流叶片控制系统存在的延迟较大、稳定性差的问题,设计了一种小脑模型神经网路(CMAC)和PID复合控制算法。该方法对状态量进行浮点编码量化,控制系统初始阶段由PID算法控制,逐渐过渡到CMAC完全控制,能提高系统的响应速度并降低稳态误差。仿真结果表明该算法比单独的PID算法具有更好的控制效果。

STUDY ON STRATEGY OF DYNAMIC JOINT ROUTING AND RESOURCE ALLOCATION IN LAYERED OPTICAL TRANSPORT NETWORKS

A layered network model for optical transport networks is proposed in this paper,which involves Internet Protocol(IP) ,Synchronous Digital Hierarchy(SDH) and Wavelength Division Mul-tiplexing(WDM) layers. The strategy of Dynamic Joint Routing and Resource Allocation(DJRRA) and its algorithm description are also presented for the proposed layered network model. DJRRA op-timizes the bandwidth usage of interface links between different layers and the logic links inside all layers. The simulation results show that DJRRA can reduce the blocking probability and increase network throughput effectively,which is in contrast to the classical separate sequential routing and resource allocation solutions.

Route optimization model for pedestrian evacuation in metro hubs

The route optimization problem for road networks was applied to pedestrian flow.Evacuation path networks with nodes and arcs considering the traffic capacities of facilities were built in metro hubs,and a path impedance function for metro hubs which used the relationships among circulation speed,density and flow rate for pedestrians was defined.Then,a route optimization model which minimizes the movement time of the last evacuee was constructed to optimize evacuation performance.Solutions to the proposed mathematical model were obtained through an iterative optimization process.The route optimization model was applied to Xidan Station of Beijing Metro Line 4 based on the actual situations,and the calculation results of the model were tested using buildingExodus microscopic evacuation simulation software.The simulation result shows that the proposed model shortens the evacuation time by 16.05%,3.15% and 2.78% compared with all or none method,equally split method and Logit model,respectively.Furthermore,when the population gets larger,evacuation efficiency in the proposed model has a greater advantage.

An analytical method to calculate station evacuation capacity

The major objective of this work was to calculate evacuation capacity and solve the optimal routing problem in a given station topology from a network optimization perspective where station facilities were modelled as open finite queueing networks with a multi-objective set of performance measures. The optimal routing problem was determined so that the number of evacuation passengers was maximized while the service level was higher than a certain criterion. An analytical technique for modelling open finite queueing networks, called the iteration generalized expansion method(IGEM), was utilized to calculate the desired outputs. A differential evolution algorithm was presented for determining the optimal routes. As demonstrated, the design methodology which combines the optimization and analytical queueing network models provides a very effective procedure for simultaneously determining the service level and the maximum number of evacuation passengers in the best evacuation routes.

A routing and positioning algorithm based on a K-barrier for use in an underground wireless sensor network

Deployment of nodes based on K-barrier coverage in an underground wireless sensor network is described. The network has automatic routing recovery by using a basic information table (BIT) for each node. An RSSI positioning algorithm based on a path loss model in the coal mine is used to calculate the path loss in real time within the actual lane way environment. Simulation results show that the packet loss can be controlled to less than 15% by the routing recovery algorithm under special recovery circum- stances. The location precision is within 5 m, which greatly enhances performance compared to tradi- tional frequency location systems. This approach can meet the needs for accurate location underground.

Vehicle Operating, Accident and User Time Costs in Pavement Management Systems： Approach for Portuguese Conditions

This paper presents a description and analysis of the most important models to predict each of the Road User Costs components （Vehicle Operating Costs, Accident Costs and Value of Time） and proposes a model for estimating RUC components suitable for the Portuguese road network. These results are part of a research which aimed to obtain a Road User Cost Model to be used as a tool in road management systems. This model is different from other models by the fact that it includes a simple formulation that allows calibration and calculation of cost parameters, for any year, in a simple and fast way, providing trustworthy results. The required data is already available in Portuguese institutions, allowing periodic revision of cost parameters to insure accuracy.

Real-time routing control design for traffic networks with multi-route choices

This work considers those road networks in which there are multi-route choices for bifurcation-destination(or origin-destination) pairs, and designs a real-time variable message sign(VMS)-based routing control strategy in the model predictive control(MPC) framework. The VMS route recommendation provided by the traffic management authority is directly considered as the control variable, and the routing control model is established, in which a multi-dimensional control vector is introduced to describe the influence of route recommendations on flow distribution. In the MPC framework, a system optimum routing strategy with the constraints regarding drivers' acceptability with recommended routes is designed, which can not only meet the traffic management authority's control requirement but also improve drivers' satisfaction with the route guidance system. The simulation carried out shows that the proposed routing control can effectively mitigate traffic congestion, reduces followers' time delay, and improves drivers' satisfaction with routing control in road networks.

Heat Transfer and Flow Analysis in Loop Heat Pipe with Multiple Evaporators Using Network Model

Thermal performance of a loop heat pipe with two evaporators and two condensers was examined using a lumped network model analysis. Thermosyphon-type vertical loop heat pipe and capillary-pump-type horizontal loop heat pipe were calculated by examining the change of heating rate of two evaporators. Calculation results showed that the vapor and liquid flow rates in the loop heat pipe and the thermal conductance of the heat pipe changed significantly depending on the distribution ratio of the heating rate of the multiple evaporators. The thermal performance of the vertical loop heat pipe with two evaporators was also examined and experimental results of flow direction and thermal conductance of the heat pipe agreed with the analytical results. The lumped network model analysis is therefore considered accurate and preferable for the practical design of a loop heat pipe with multiple evaporators.

An uplink power control algorithm using traditional iterative model for cognitive radio networks

Based on the analysis of the feature of cognitive radio networks, a relevant interference model was built. Cognitive users should consider especially the problem of interference with licensed users and satisfy the signal-to-interference noise ratio （SINR） requirement at the same time. According to different power thresholds, an approach was given to solve the problem of coexistence between licensed user and cognitive user in cognitive system. Then, an uplink distributed power control algorithm based on traditional iterative model was proposed. Convergence analysis of the algorithm in case of feasible systems was provided. Simulations show that this method can provide substantial power savings as compared with the power balancing algorithm while reducing the achieved SINR only slightly, since 6% S1NR loss can bring 23% power gain. Through further simulations, it can be concluded that the proposed solution has better effect as the noise power or system load increases.

MILITARY MULTI-HOP ROUTING PROTOCOL

Military tactical network is one of the most important applications of ad hoc network. Currently the existing routing protocols are put forward based on the simple and universal network model which has the ability of multi-hop routing but cannot work efficiently in the special military applications. The narrow bandwidth and limited energy of the wireless network make general routing protocols seem to be more redundant. In order to satisfy military needs properly, this letter makes a detailed analysis of physical nodes and traffic distribution in military network, uses cross-layer design concept tbr reference, combines traffic characteristic of application layer with routing protocol design. It categorized routing problem as crucial routes and non-crucial routes which adopted separate maintenance methods. It not only realizes basic transmission function but also works efficiently. It is quite fit for military application.