Computer Engineering Commons^™

Extreme Image Compression With Deep Learning Autoencoder, Licheng Xiao

Computer Science and Engineering Master's Theses

Image compression can save billions of dollars in the industry by reducing the bits needed to store and transfer an image without significantly losing visual quality. Traditional image compression methods use transform, quantization, predictive coding and entropy coding to tackle the problem, represented by international standards like JPEG (joint photographic experts group), JPEG 2000, BPG (better portable graphics), and HEIC (high efficiency image file format). Recently, there are deep learning based image compression approaches that achieved similar or better performance compared with traditional methods, represented by autoencoder, GAN (generative adversarial networks) and super-resolution based approaches.

In this paper, we built …

Multi-Agent Simulation Model Of Urban Safety Livability Change, Lihu Pan, Xiaowen Li, Shipeng Qin, Yingjun Zhang, Huimin Yan

Journal of System Simulation

Abstract: Urban livability is an important factor for the decision of modern urban construction. Based on the multi-agent modeling theory, a model for the change of urban livability is proposed, so as to analyze the present situation and changing trend of urban livability in complex urban system. Taking safety as an example, five environmental indicators of public security, fire protection, traffic, emergency response and residence are given. The interactive dynamic feedback mechanism between residents' decision-making behavior and urban safety livability under the influence of the five indicators and policies is provided, and the residents' decision-making simulation of urban safety livability …

Personalized Music Recommendation Algorithm Tfpmf, Xining Ye, Wang Meng

Journal of System Simulation

Abstract: In recent years, the personalized context-aware recommendation is the rub and hotness in the research of recommendation system, and the data sparseness is the main problem faced by the current recommendation systems. In the setting of music recommendation, the representing method of varieties of situational information is improved. A model of TFPMF is proposed, which combines the model of RR-PMF with the tensor decomposition. TFPMF is optimized by alternative least squares (ALS). By the simulation experiments in the last.fm dataset, we got the TOP-N recommended list through the simulation program. The simulation results show that the proposed algorithm has …

High-Dimensional Data Hiding Pattern Mining Based On Topology Data Analysis, Bolong Liu, Zhe Li

Journal of System Simulation

Abstract: Aiming at the limitation of traditional data analysis methods to find hidden patterns between high-dimensional complex data, a method of high-dimensional data hiding pattern mining based on topological data analysis is proposed. By extracting the characteristics of complex high-dimensional data, the relationship between its shapes and samples is analyzed. To get the dataset hidden mode, the topological data analysis is used to verify the gender recognition of high-dimensional dataset-voice.. At the same time, the relationship between the dataset data subgroups and related data subgroups is visually analyzed. The results show that the implicit relationship and pattern between data subgroups …

Analyzing The Pedestrian Evacuation Efficiency In Architecture Based On Different Facilities Layout, Zhihong Li, Yanjie Wen, Wangtu Xu, Qi Yue

Journal of System Simulation

Abstract: Pedestrians escaping from the architecture are restricted by limited time and space. There are so many different exits, channels and bottleneck. Three kinds of facilities layout were designed to be initial schemes. The shortest escaping time was estimated by the different bottlenecks. Then, a safety escaping model based on the facilities layout and dynamic information was proposed, and the escaping time, area density and evacuation efficiency were analyzed by the simulation. The research indicates that by calculating and simulating the model can estimate the evacuation time for different schemes, and the result can provide some advices for facilities layout.

Teaching And Training Platform For Virtual Equipment Of Replenishment Based On Web3d, Li Nan, Shiyun Zhang

Journal of System Simulation

Abstract: In view of the problem that military simulation training system can't maximize to the advantages of virtual reality simulation technology because of the limitations of regional, space and training ability, this paper developed a virtual equipment training and teaching platform. It made a large-scale compression for 3D models and map data. Meanwhile it made streaming and multithreading download of compressed data through the HTTP protocol. It dealt with the high concurrent access on network by using the balanced load. So that it has broken the limitations of regions space and training ability of the previous military simulation training system, …

Virtual Scene Roaming Method Supporting Multi-Layer Path Planning, Shi Min, Yukun Wei, Xiangchen Jin, Suqin Wang, Tianlu Mao

Journal of System Simulation

Abstract: Taking the automatic role pathfinding in three-dimensional virtual scene as the research background, the author proposes a method of multi-layer pathfinding based on A-star algorithm, and uses advanced heuristic functions to evaluate the cost values of various expansion nodes to confirm the optimal solution to the problems. By introducing collision detection mechanism, the navigation path generated by the improved A* algorithm is modified to avoid collision; and by interpolating the fixed path, the smooth navigation path is constructed using Bézier Curve. The experimental results show that the path finding results can well adapt to the multi-layer case when the …

Ads-B In Based Conflict Prediction And Conflict-Free Trajectory Planning For Multi-Aircraft, Siyuan Zhang, Xianying Li, Xiaoyun Shen

Journal of System Simulation

Abstract: For free flight of future, it is necessary to continuously detect conflicts and plan safe flight paths. Through in-depth analysis of detection principle of TCAS, combined with the characteristics of ADS-B data, the target within the scope of ADS-B IN surveillance is classified and given a risk factor, and the TCAS function is implemented in the ADS-B IN simulation software. For complex conflict scenarios with multi-aircraft, by meshing the conflict region and discretizing the flight procedure, the genetic algorithm is then used to calculate the optimal conflict-free trajectory based on risk factors. Two common multi-aircraft conflict scenarios are …

Characteristic Index Digging Of Combat Sos Capability Based On Machine Learning, Yongli Yang, Xiaofeng Hu, Rong Ming, Xiaojing Yin, Wenxiang Wang

Journal of System Simulation

Abstract: Aiming at the two difficulties in characteristic index digging of combat system of systems (CSoS), namely operation data generation and digging method selection, this paper proposes a new digging method, that is, using the simulation testbed to generate operation data, then adopting the machine learning to dig characteristic index. Two methods of characteristic index digging based on machine learning are researched: (1) the method based on network convergence, divides the communities for fundamental indexes based on their relationship, and obtains the characteristic indexes by principal component analysis (PCA); this method is applied to dig the characteristic indexes of …

Modeling And Simulation Of Financial Contagion Based On Correlated Assets Portfolio, Fan Hong, Chunyao Liu

Journal of System Simulation

Abstract: The correlation of assets portfolio in financial institutions is an important cause of indirect financial contagion, but the modeling of this problem has not been studied yet. Considering the correlation between the assets invested by financial institutions, a dynamic evolution model and the simulation algorithm of financial network system based on correlated assets portfolio are constructed; and the impact of assets portfolio correlation, degree of assets diversity and market density (the ratio of financial institutions to assets) on financial contagion are studied. Simulation results show that the positive correlation between assets portfolio exacerbates financial contagion, while the negative correlation …

Data Model Of Battlefield Geographic Environment Simulation Object Based On Cognition, Zhu Jie, You Xiong, Xia Qing

Journal of System Simulation

Abstract: Aiming at the urgent demands on present battlefield environment cognition active service, its requirements are hard to be satisfied by the traditional battlefield environment data model, thus a kind of battlefield environment simulation data model needs to be constructed. The characteristics of task-orientated battlefield geographic space cognition progress are analyzed, and the cognitive process concept model is constructed. The characteristics of battlefield environment object recognition structure are analyzed; the hierarchical structure division is implemented on battlefield geographic environment simulation object with object-orientated method; and object data models are described uniformly with SEDRIS. Based on cognitive-driven mechanism of workflow, the …

Human Re-Identification Based On Part Segmentation, Jiang Hua, Zhang Liang

Journal of System Simulation

Abstract: Human re-identification is a difficult problem to solve in process of video analysis of non-overlapping multi-camera surveillance system. A new algorithm of human re-identification is proposed on the basis of human part segmentation. Based on the depth of bone points to achieve the human body segmentation, the optimal key frame is selected by using the scoring strategy for all parts of the same human multi-frame image segmentation; the different weights for the global color feature and the HOG feature are assigned; all the characteristics to establish a human target model are combined; and the EMD (Earth Mover’s …

Jammer Placement Algorithm Based On Particle Swarm Optimization, Fang Fang, Chunming Ye, Haibo Liu

Journal of System Simulation

Abstract: A novel jammer placement algorithm based on particle swarm optimization is proposed to solve the problems of nodes’ mobility and restrictions on placement areas in ad-hoc network. There are three steps in this algorithm: network simulation, jamming simulation, and optimization. The algorithm simulates the network communication process and movement of nodes with discrete simulation method. Simple particle swarm optimization is applied to compute the exact coordinates of jammers. Experiment results show that this algorithm is good at jamming network nodes moving in different ways. The algorithm has stable performance with varying conditions such as different placement areas, jamming …

Low-Cost Hardware-In-The-Loop Flight Simulation System, Chuanyan Tian, Junzhao Hu, Jikui Liu, Qianlong Yang

Journal of System Simulation

Abstract: Hardware-in-the-loop simulation is an effective way and experimental method to evaluate and verify the performance of the aircraft system. To satisfy the requirements of real-time, scalability, high reliability simulation of a certain aircraft control system, a new design of low-cost hardware-in-the-loop real-time scene simulation system consisted of IPC, DSP, three-axis turntable, steering engine and visual simulation computer was put forward. Real-time simulation system software composed by flight control simulation module, aircraft movement simulation module and scene simulation module was implemented, and it resolved the difficulties in real-time, data synchronization, multiple node communication of simulation system. Comparison with …

Design And Implementation Of Parallel Central Securities Trading Simulation System, Guangbin Xu

Journal of System Simulation

Abstract: Chinese securities market has become a worldly very important finance pricing center. As the core facilities of the markets, the central securities trading systems of stock exchanges have been upgraded continually. Both Shanghai and Shenzhen Stock Exchanges currently adopt the third-generation central securities trading systems to support respective business requirements, which are both based on the advanced parallel processing paradigm. To support various securities trading simulation experiments of the Chinese markets, referring to NGTS, the central trading system currently-used by Shanghai Stock Exchange, a PC-based simulation system is designed and implemented, which can support full market data distribution and …

Fire Emergency Evacuation Simulation Of Vertical Ship Lift, Jianping Wang, Meiru Wang, Chen Shu, Chengyou Liu, Li Zhi

Journal of System Simulation

Abstract: In order to analyze the fire evacuation efficiency of vertical ship lift, the influence of population characteristics on evacuation is analyzed quantitatively from three aspects, such as age structure, population density and flow velocity. According to the emergency evacuation path of vertical ship lift, the three-stage evacuation time is divided into three parts. In order to obtain fire evacuation time, the model of vertical ship lift with the passenger ship is established and parameters of evacuation time are set up by using the simulation technology. The actual case of the Three Gorges ship lift shows:1) the evacuation …

Fatigue Life Prediction Of Turbine Blades Based On Qar Data, Pi Jun, Shuwei Gao, Jiangbo Huang, Huang Lei, Ma Long

Journal of System Simulation

Abstract: Based on the characteristics of the high-pressure turbine blade, a numerical simulation method for the actual load spectrum of the high-pressure turbine blade of the civil aircraft engine based on the QAR data is proposed. The actual service load spectrum of the engine recorded during aircraft flight is extracted from the QAR data; the time history of centrifugal force, aerodynamic force and thermal stress of the turbine blade in actual use is obtained by means of finite element simulation; and with life prediction model, the actual service life of the blade is estimated. This method provides a reliable …

Review Of Evaluation Methods Of Contribution Rate To System Of Systems, Xiaojing Yin, Xiaofeng Hu, Rong Ming, Haiyang Liu, Yongli Yang

Journal of System Simulation

Abstract: The warfare is the encounter of system of systems (SoS). The evaluation on the contribution rate to SoS is of great importance to the development of operational SoS as a measure of the evaluating units’ contribution to SoS. In this paper the basic concept and classification of the contribution rate to operational SoS are elaborated; its connotation and nature are analyzed; and the current research status and the technical difficulties in this research field are summarized. The development trend is predicted, which provides a useful reference for relative research.

Pshev Cold Start Emission Simulation Based On Electric Heated Catalyst Pre-Heating, Deng Tao, Haoyuan Yu, Zhifei Li, Haixin Tan

Journal of System Simulation

Abstract: In order to reduce the emissions of the plug-in series hybrid electric vehicle (PSHEV) during the cold start phase, a vehicle model on PSHEV is established and a dynamic model of electrically heated catalyst system (EHCS) based on optimization and control strategy of engine start-stop is built. The PSHEV energy management control strategy based on EHCS preheating is proposed. The influence of different pre-heating power on EHCS temperature is simulated. By comparing SOC value of the control strategy with the original control strategy; and comparative analysis of cold start emissions of three elements catalyst under three strategies of pre-heating, …

Reaction Force Of Ship Bearing Including Multi Factors, Shengdong Zhang, Xiuying Yang

Journal of System Simulation

Abstract: Since the variety and complexity of the stern bearing's operational environment and working conditions, the stern bearing load has uncertainty characters. The mathematical model of uncertainty reaction force of bearing is established including multiple random factors by using the stochastic theory; the uncertainty calculation method is formulated; and the calculation example is put forward to verify the validity of the theoretical model. The influence law among multi factors such as hull deformation, propeller hydrodynamic vertical force and bearing wear is revealed for the uncertainty reaction force of ship stern bearing by taking a large container ship as example. …

Analysis Of Amplitude-Frequency Characteristics Of Fractional-Order Current-Controlled Meminductor, Liu Meng, Zhaohui Gan, Shiying Zhang

Journal of System Simulation

Abstract: Meminductor is a nonlinear memory element with hysteresis characteristics, which is an important part of memristive systems. In recent years, meminductor research is mainly focused on time domain characteristics, but the research of frequency domain characteristics of meminductor has not been seen report. A fractional-order current-controlled meminductor model with nonlinear window function is studied, and the amplitude-frequency response characteristics of meminductor under different excitation signals are analyzed in detail. The influence of fractional-order and control parameter in window function on amplitude-frequency characteristics of the fractional-order current-controlled meminductor is summarized. It has certain guiding significance to research of meminductor characteristics.

Evaluation Of Stealth Aircraft Approaching Support Jamming Performancefrom Detection Probability, Bao Lei, Chunyang Wang, Huiyong Zeng, Bai Juan

Journal of System Simulation

Abstract: Aiming at the problem of how to construct an effective model to evaluate the reasonableness of detection performance when a radar detects a third-generation aircraft covered by an approaching support jamming performance of stealth aircraft, a stealth aircraft jamming model based on diving to the near support track is proposed. After calculating the aircraft attitude angle, the time-varying dynamic RCS series are extracted. Using Swerling IV distribution, the characteristics of radar instantaneous detection probability time-varying in penetration jamming between normal flight and stealth aircraft are studied and compared. Simulation results show that the radar detection probability can be reduced …

Simulation Research On Damage Identification Of Simply Supported Beam Based On Wavelet Packet Energy Method, Xijun Liu, Xiankun Tao, Suxia Zhang

Journal of System Simulation

Abstract: A finite element model of simply-supported beam is built by ANSYS;the displacement response of the beam is used to make wavelet packet analysis with MATLAB to get the curvature difference of WP-E (wavelet packet energy);and the studies on the effects of different parameters on damage recognition results of simple beam bridge are carried out, such as damage locations, damage level, measuring point density and speed of moving loads. For the condition of less measuring points, a method of arranging the measuring points by two steps is proposed. The normalized curvature difference of WP-E is made to study the …

Review Of Simulation Model Validation Methods, Li Wei, Yuchen Zhou, Shenglin Lin, Ma Ping, Yang Ming

Journal of System Simulation

Abstract: Modeling and simulation has become an important way to cognize and research objective world, and the credibility of simulation models is the premise and basics for carrying out simulation activities. The ever-increasing complexity of the simulation objects and demands of simulation applications for users lead to a great challenge in validation of complex simulation model, which characterize a variety of complex features. This paper aims to summarize the concepts and development of simulation model validation, classify existing validation methods, analysis the applicable conditions of these methods and provide a brief review of some new validation methods. Furthermore, some emerging …

Some Problems And Countermeasures In Simulation Credibility Evaluation, Jiao Peng, Zhang Qi, Xiangyu Wei, Yabing Zha

Journal of System Simulation

Abstract: With the increasing application of simulation technology in various fields, users have put forward higher requirements for the credibility of the simulation system. This paper focuses on some key issues of the credibility evaluation of the simulation system, such as the unclear expected application, the incomplete evaluation, the unclear evaluation criteria, and the open loop of evaluation conclusions. From the perspectives of comprehensive implementation of credibility assessment, strengthening the design of acceptability standards, and focusing on the evaluation of closed-loop implementation, how to solve the real problem has been studied and discussed. The research results of this paper …

Osgearth Stereoscopic Vision Generation Method For Hmd-Based Virtual Reality, Liheng Tan, Ma Qiang, Bingchuan Jiang, Li Feng

Journal of System Simulation

Abstract: The technology of immersive virtual reality based on helmet mounted display (HMD) has become a focus of study, however, its visual content is mainly produced through commercial game engines. OsgEarth is an open-source, state-of-the-art and widely used digital earth simulation system. Based on this, we studies the stereoscopic vision generation method for global virtual terrain environment, mainly focusing on: stereoscopic vision theory; construction of global high-precision virtual geographical environment; calculation of binocular view frustrum; system integration. The proposed method is verified under the hardware conditions of PC and HTC VIVE, which can generate stereo images of the global virtual …

Three-Dimensional Cloud Simulation Of Satellite Cloud Map Based On Sph Method, Zhou Hao, Shuoben Bi, Yucheng Gong, Wang Jun, Dequan Ling

Journal of System Simulation

Abstract: A fast cloud three-dimensional simulation algorithm based on smoothed particle hydrodynamics (SPH) is proposed. The two-dimensional contours of the real cloud are extracted from the satellite cloud image, and the cloud contour curves are fitted with different levels of circular clouds. The obtained circle is extended to the three-dimensional space with the center and the radius as necessary to form the spherical shape. According to the principle of SPH, a certain number of particles are generated in the generated cloud three-dimensional sphere; and the particles are given the initial properties such as color, size, speed and smooth kernel, so …

Analysis Of Initialization Variables Selection In Multi-Domain Modeling, Guangyuan Li

Journal of System Simulation

Abstract: In multi-domain modeling, the problem of initial consistency must be settled to solve differential algebraic equations (DAEs). Structural analysis is capable of verifying the initial consistency, solving some initial values and determining the degree of freedom, but not capable of affirming the variables that need to be initialized. If improper selection is made for the initiation variables, it will become low efficient and even fail to solve and simulate the model. After analyzing the initial consistency of DAEs, a strategy based on DM decomposition is proposed for selecting the initialization variables. The method decomposes the system into two …

Simulation Platform For Invulnerability Of Industrial Wireless Sensor Networks, Xiuwen Fu, Yongsheng Yang

Journal of System Simulation

Abstract: Existing simulation platforms for industrial wireless sensor networks (IWSNs) mainly focus on the general scenario and fail to take into consideration the impacts of interference brought by external environments and emergencies on network performance, thus failing to evaluate the network invulnerability. For given the environment-impacted and event-driven features of IWSNs, the connections between network invulnerability and deployment environment are built. On this basis, a simulation platform for invulnerability of IWSNs is proposed by introducing deployment environment component and event creator. Experiments show that the platform is capable of evaluating the invulnerability of IWSNs.

Design And Implementation Of Interactive Ar System For Campus Roaming, Shengwei Qin, Li Zhong, Jinfeng Li, Zihao Chen, Jingqian Ding, Wanshun Liu

Journal of System Simulation

Abstract: There are many kinds of navigation applications in universities recently. These applications have obvious shortcomings, which only indicate the outdoor locations without detail information; even some places cannot be found in the map; and it takes a lot of time to design a system. Meanwhile the system cannot achieve real-time interaction effect in virtual ramble. An interactive campus roaming augmented reality (AR) system is designed combining with GPS module for locating outside the campus and utilizing deep learning technology to achieve locating the inside buildings of campus. Simultaneously AR technology will improve interactivity of the system. The experiment …