A Novel Collective User Web Behavior Simulation Method

A collective user web behavior simulation is an import means for generating a large-scale user network behavior in a network testbed or cyber range.Existing studies almost focus on individual web behavior analysis and prediction,which cannot simulate human dynamics that widely exist in large-scale users’behaviors.To address these issues,we propose a novel collective user web behavior simulation method,in which an algorithm for constructing a connected virtual social network is proposed,and then a collective user web behavior simulation algorithm is designed on the virtual social network.In the simulation method,a new epidemic information dissemination algorithm based on the SIR model is proposed to drive the user web behavior with Breadth—First Search algorithm on the connected virtual social network.We specially build an experiment environment with 12 servers by using Docker container technology and then perform a wide range of experiments with different user scales to evaluate the method.The experimental results demonstrate that not only the degrees of the social network but also the time intervals of the collective users’web behavior can be well fitted to a power-law distribution and show that our simulation method can well simulate a collective user web behavior.

Numerical simulation and experimental verification of bubble size distribution in an air dense medium fluidized bed

Bubble size distribution is the basic apparent performance and obvious characteristics in the air dense medium fluidized bed (ADMFB). The approaches of numerical simulation and experimental verification were combined to conduct the further research on the bubble generation and movement behavior. The results show that ADMFB could display favorable expanded characteristics after steady fluidization. With different particle size distributions of magnetite powder as medium solids, we selected an appropriate prediction model for the mean bubble diameter in ADMFB. The comparison results indicate that the mean bubble diameters along the bed heights are 35 mm < D b < 66 mm and 40 mm < D b < 69 mm with the magnetite powder of 0.3 mm+0.15mm and 0.15mm+0.074mm, respectively. The prediction model provides good agreements with the experimental and simulation data. Based on the optimal operating gas velocity distribution, the mixture of magnetite powder and <1mm fine coal as medium solids were utilized to carry out the separation experiment on 6-50mm raw coal. The results show that an optimal separation density d P of 1.73g/cm 3 with a probable error E of 0.07g/cm 3 and a recovery efficiency of 99.97% is achieved, which indicates good separation performance by applying ADMFB.

Simulation of nonlinear behavior in an electron cyclotron resonance plasma

Some nonlinear behavior in electron cyclotron resonance plasma was investigated using a two-dimension hybrid-mode with self-consistent microwave absorption. The saturation,oscillations of plasma parameters (plasma density, potential, electron temperature) versus operating conditions (pressure, power) are discussed. Our simulation results are consistent qualitatively with many experimental measurements.

Review of state-of-the-art decision support systems (DSSs) for prevention and suppression of forest fires

Forest ecosystems are our priceless natural resource and are a key component of the global carbon budget. Forest fires can be a hazard to the viability and sustainable management of forests with consequences for natural and cultural environments, economies, and the life quality of local and regional populations. Thus, the selection of strategies to manage forest fires, while considering both functional and economic efficiency, is of primary importance. The use of decision support systems(DSSs) by managers of forest fires has rapidly increased. This has strengthened capacity to prevent and suppress forest fires while protecting human lives and property. DSSs are a tool that can benefit incident management and decision making and policy, especially for emergencies such as natural disasters. In this study we reviewed state-of-the-art DSSs that use: database management systems and mathematical/economic algorithms for spatial optimization of firefighting forces; forest fire simulators and satellite technology for immediate detection and prediction of evolution of forest fires; GIS platforms that incorporate several tools to manipulate, process and analyze geographic data and develop strategic and operational plans.

Technology for Simulating Crowd Evacuation Behaviors

This paper presents a model for simulating crowd evacuation and investigates three widely recognized problems. For the space continuity problem, this paper presents two computation algorithms： one uses grid space to evaluate the coordinates of the obstacle＇s bounding box and the other employs the geometry rule to establish individual evacuation routes. For the problem of collision, avoidance, and excess among the individuals, this paper computes the generalized force and friction force and then modifies the direction of march to obtain a speed model based on the crowd density and real time speed. For the exit selection problem, this paper establishes a method of selecting the exits by combining the exit＇s crowd state with the individuals. Finally, a particle system is used to simulate the behavior of crowd evacuation and produces useful test results.

Grid-based internet worm behavior simulator

The traditional network simulator has function and performance limitation when simulating Internet worms,so we designed the grid-based Internet worm behavior simulator (IWBS Grid).IWBS Grid makes use of the real Internet topology,link and routing information,and simulates the worm behavior at the packet event-driven level;and proposes a high-performance Internet worms behavior simulation platform by right of the grid computing capability,resource and task management,and so on.The experimental results show that IWBS grid surpasses the traditional simulator in simulating capability,and the technology to track the worm propagation in packet level can propose the valuable information for the further study on worms.

Simulation and visualization of spraying droplets behavior and deposition within virtual rice canopy

Models for accurately simulating pesticide droplet deposition and transmission mechanism in rice canopies can provide an effective and economic tool to optimize methods for spraying pesticides,adjuvant formulation,and spray parameters.However,the current studies on the modeling of spray droplet deposition within rice plants are still very limited.Aiming at this problem,a method to model and visualize spray transmission and deposition within the canopy of rice plants was proposed.Firstly,a particle system was used to simulate the spraying scene of droplets.Then an improved method to determine the behavior of rebound and shatter of the droplets in the virtual scene was proposed.The deposition of spraying droplets on a leaf was calculated according to the inclination angles of the leaf,the characteristics of the leaf surface,and the physical and spatial characteristics of the droplets.The experiment shows that the method can simulate the behavior of the spraying droplets within a virtual scene of a rice plant,which may provide a reference for the study of spray deposition in the canopy of the crop.

Hand Interface in Traditional Modeling and Animation Tasks

3-D task space in modeling and animation is usually reduced to the separate control dimensions supported by conventional interactive devices. This limitation maps only patial view of the problem to the device space at a time, and results in tedious and un natural interface of control. This paper uses the DataGlove interface for modeling and animating scene behaviors. The modeling interface selects, scales, rotates, translates,copies and deletes the instances of the prindtives. These basic modeling processes are directly performed in the task spacet using hand shapes and motions. Hand shapes are recoginzed as discrete states that trigger the commands, and hand motion are mapped to the movement of a selected instance. The interactions through hand interface place the user as a participant in the process of behavior simulation. Both event triggering and role switching of hand are experimented in simulation. The event mode of hand triggers control signals or commands through a menu interface. The object mode of hand simulates itself as an object whose appearance or motion inlluences the motions of other objects in scene. The involvement of hand creates a diversity of dyndric situations for testing variable scene behaviors. Our experiments have shown the potential use of this interface directly in the 3-D modeling and animation task space.