Numerical Analysis and Scientific Computing Commons^™

Neural Multimodal Belief Tracker With Adaptive Attention For Dialogue Systems, Zheng Zhang, Lizi Liao, Minlie Huang, Xiaoyan Zhu, Tat-Seng Chua

Research Collection School Of Computing and Information Systems

Multimodal dialogue systems are attracting increasing attention with a more natural and informative way for human-computer interaction. As one of its core components, the belief tracker estimates the user's goal at each step of the dialogue and provides a direct way to validate the ability of dialogue understanding. However, existing studies on belief trackers are largely limited to textual modality, which cannot be easily extended to capture the rich semantics in multimodal systems such as those with product images. For example, in fashion domain, the visual appearance of clothes play a crucial role in understanding the user's intention. In this …

On-The-Fly Android Static Analysis With Applications In Vulnerability Discovery, Daoyuan Wu

Dissertations and Theses Collection (Open Access)

Static analysis is a common program analysis technique extensively used in the software security field. Widely-used static analysis tools for Android, e.g., Amandroid and FlowDroid, perform the whole-app analysis which is comprehensive yet at the cost of huge overheads. In this dissertation, we make a first attempt to explore a novel on-demand analysis that creatively leverages bytecode search to guide inter-procedural analysis on the fly or just in time, and develop such on-the-fly analysis into a tool, called BackDroid, for Android apps. We further explore how the core technique of on-the-fly static analysis in BackDroid can enable different vulnerability studies …

Faster: Fusion Analytics For Public Transport Event Response Industrial Applications Track, Sebastien Blandin, Laura Wynter, Hasan Poonawala, Sean Laguna, Basile Dura

Research Collection School Of Computing and Information Systems

The Autonomous Agents and Multiagent Systems (AAMAS) conference series gathers researchers from around the world to share the latest advances in the field. It is the premier forum for research in the theory and practice of autonomous agents and multiagent systems. AAMAS 2002, the first of the series, was held in Bologna, followed by Melbourne (2003), New York (2004), Utrecht (2005), Hakodate (2006), Honolulu (2007), Estoril (2008), Budapest (2009), Toronto (2010), Taipei (2011), Valencia (2012), Saint Paul (2013), Paris (2014), Istanbul (2015), Singapore (2016), São Paulo (2017) and Stockholm (2018). This volume is the proceedings of AAMAS 2019, the 18th …

Powers And Behaviors Of Directed Self-Assembly, Trent Allen Rogers

Graduate Theses and Dissertations

In nature there are a variety of self-assembling systems occurring at varying scales which give rise to incredibly complex behaviors. Theoretical models of self-assembly allow us to gain insight into the fundamental nature of self-assembly independent of the specific physical implementation. In Winfree's abstract tile assembly model (aTAM), the atomic components are unit square "tiles" which have "glues" on their four sides. Beginning from a seed assembly, these tiles attach one at a time during the assembly process in an asynchronous and nondeterministic manner.

We can gain valuable insights into the nature of self-assembly by comparing different models of self-assembly …

Pptds: A Privacy-Preserving Truth Discovery Scheme In Crowd Sensing Systems, Chuan Zhang, Liehuang Zhu, Chang Xu, Kashif Sharif, Ximeng Liu

Research Collection School Of Computing and Information Systems

Benefiting from the fast development of human-carried mobile devices, crowd sensing has become an emerging paradigm to sense and collect data. However, reliability of sensory data provided by participating users is still a major concern. To address this reliability challenge, truth discovery is an effective technology to improve data accuracy, and has garnered significant attention. Nevertheless, many of state of art works in truth discovery, either failed to address the protection of participants' privacy or incurred tremendous overhead on the user side. In this paper, we first propose a privacy-preserving truth discovery scheme, named PPTDS-I, which is implemented on two …

Community Detection Via Neighborhood Overlap And Spanning Tree Computations, Ketki Kulkarni, Aris Pagourtzis, Katerina Potika, Petros Potikas, Dora Souliou

Faculty Publications, Computer Science

Most social networks of today are populated with several millions of active users, while the most popular of them accommodate way more than one billion. Analyzing such huge complex networks has become particularly demanding in computational terms. A task of paramount importance for understanding the structure of social networks as well as of many other real-world systems is to identify communities, that is, sets of nodes that are more densely connected to each other than to other nodes of the network. In this paper we propose two algorithms for community detection in networks, by employing the neighborhood overlap metric …

Orca Travel Grant Recipient An Interview With Emily Hoard, Emily Hoard

Steeplechase: An ORCA Student Journal

No abstract provided.

Multi-Chromosome Genetic Algorithm For Multiple Traveling Salesman Problem, Duofu Ye, Liu Gang, He Bing

Journal of System Simulation

Abstract: A multi-traveling salesman model with time window is established, and two objective functions for the number of traveling salesmen and the sum of travel time are designed. A multi - chromosome coding method is designed to develop complex mutation operator tree, which overcomes the problem of large searching space of traditional genetic algorithms. The performances of algorithms are compared by simulation, and the simulation results show that the genetic algorithm with complex multi-chromosome mutation tree can balance the two objective functions of the number of TSP and total travel time well, improve the algorithm of travel speed, and reduce …

Virtual Scene Simulation Of Pilot Response In Taking-Off And Landing Processes Of Carrier-Based Aircraft, Ke Peng, Chenglin Xu, Songyang Liu, Minggao Li, Zhao Xin

Journal of System Simulation

Abstract: A research and implementation method based on biomechanics simulation and virtual scene simulation was put forward to investigate the dynamics responses of pilots during the taking off and landing processes of carrier-based aircraft. The human biomechanics calculation of pilots and 3D virtual scene simulation of flight scene were combined to design and develop the integrated virtual simulation platform. This platform has the functions of data management and analysis, human biological dynamics calculation, synchronous analysis of key results, 3D virtual scene simulation of taking-off and landing processes and human response. The verification was carried out using the experiments from …

Modeling And Timing Simulation Of Turbojet Engine Starting Process, Wang Lei, Liying Yang, Hongda Zhang, Yuqing He

Journal of System Simulation

Abstract: The turbojet engine is complicated in its starting process and requires collaboration and cooperation involving all the execution structures, thus higher demand is put forward for the control system. How to model the engine starting process, and then accurately describe and analyze the impact of actuator states on engine performance directly affect the engine control system performance. According to the working principle of the JetCat-P400 German turbojet starting process, the rotor speed mathematical model of the turbojet engine starting process is constructed by the component method. The parameters of the model are identified by combining the experimental data of …

Evaluation Of Green Smart Cities In China Based On Entropy Weight - Cloud Model, Chen Li, Haixia Zhang

Journal of System Simulation

Abstract: Based on the research on green smart city at home and abroad; and aiming at the shortcomings and deficiencies of traditional evaluation methods, this paper proposes an evaluation method of combining entropy and cloud model based on the cloud model which can realize the conversion of qualitative concept and quantitative value. This method synthetically considers the subjective and objective factors; carries on the correlation analysis to the index; determines the set of evaluation indicators; uses the X-conditional cloud generator in cloud model to obtain the different levels of membership matrix corresponding to each evaluation object; and carries on the …

Dp-Q(Λ): Real-Time Path Planning For Multi-Agent In Large-Scale Web3d Scene, Fengting Yan, Jinyuan Jia

Journal of System Simulation

Abstract: The path planning of multi-agent in an unknown large-scale scene needs an efficient and stable algorithm, and needs to solve multi-agent collision avoidance problem, and then completes a real-time path planning in Web3D. To solve above problems, the DP-Q(λ) algorithm is proposed; and the direction constraints, high reward or punishment weight training methods are used to adjust the values of reward or punishment by using a probability p (0-1 random number). The value from reward or punishment determines its next step path planning strategy. If the next position is free, the agent could walk to it. The above strategy …

Robust Adaptive Rate Control Algorithm And Its Simulation For P2p-Tv Streaming Media Systems, Fengjie Yin, Yang Hui, Zhang Ying

Journal of System Simulation

Abstract: A control algorithm proposed to control the upstream rate based on sliding mode control in P2P-TV streaming media node. Through the rational design of sliding mode controller, the algorithm can adaptively control the numbers of signaling threads between neighbor pairs connected simultaneously and then control the upload rate. Further, it can achieve the fair use of resources. Due to the sliding mode control has strong robust with modeling uncertainties, time varying parameter fluctuations and external disturbances, it can avoid the system congestion under network condition change. Simulation results demonstrate that it can lead to the convergence of the …

Modeling And Simulation Of Health Degradation Trend For Wind Turbine Bearing, Xinghui Dong, Xiaoshuang Ma, Youxing Cheng, Wang Shuai

Journal of System Simulation

Abstract: By taking a wind turbine bearing as research object, the model of bearing temperature health’s degradation trend is established through using least squares surface fitting and the monitored parameters from Supervisory Control And Data Acquisition (SCADA). Bearings’ degradation trend with unsteady characteristics is decomposed by modified Ensemble Empirical Mode Decomposition(EEMD) to obtain several relatively steady components. Components are predicted respectively by time series neural network and the predicted results of all the components are added to obtain final prediction result. Comprehensive simulations and comparisons show that the proposed method can predict the health degradation trend of wind turbine bearings …

New Clock-Driven Algorithm Based On Separation Of Synaptic Conductance Computation, Zhijie Wang, Peng Xia, Han Fang, Xiaochun Gu

Journal of System Simulation

Abstract: In order to reduce the computing time when simulating the biologic neural network, an efficient clock-driven algorithm based on the separation of synaptic conductance computation is presented. It is found that the calculation of the synaptic state variables can be separated into two independent parts: one called conductance coefficient related with the pre-synaptic neuron, and the other called synaptic current. By introducing the data structure of the virtual synapse cluster to storing sequences of synaptic conductance coefficient, the former part can be calculated independently according to the spiking states of pre-synaptic neuron at each time step. When calculating the …

Image Feature Extraction And Online Grading Method For Weight And Shape Of Strawberry, Zhang Qing, Xiangjun Zou, Guichao Lin, Yanhui Sun

Journal of System Simulation

Abstract: To deal with the classification problems of strawberry in production, a machine vision based strawberry weight and shape grading method was proposed. The strawberry image was segmented by thresholding to extract the fruit. The area and perimeter parameters of the fruit were then calculated and used to build the strawberry weight grading model through regression analysis. Elliptic Fourier descriptor was used to extract the shape features of the fruit, and these shape features were applied to train a support vector machine (SVM) which represented the strawberry shape grading model. 200 samples of strawberries were selected to test both …

Modeling And Simulation Of False Report Filtering Scheme Based On Position In Wireless Sensor Networks, Zhixiong Liu, Limiao Li

Journal of System Simulation

Abstract: In wireless sensor networks, the adversary can inject false reports from compromised nodes. Previous security designs cannot detect faked reports that are forged coordinately by a group of compromised nodes. Furthermore, in sparse areas, some events failed to be reported to sink. This paper proposes a position based filtering scheme (PFS). It derives the optimal coverage degree ω, and the nodes are deployed accordingly. After deployment, each node distributes its position to some other nodes. When a report is generated for an observed event, it must carry t distinct MACs (Message Authentication Codes) along with positions of all detecting …

Design And Realization Of Ship Virtual Fire Training System Based On Hmd, Zhang Bo, Sun Jun, Shang Lei, Hongji Xu, Yang Cheng

Journal of System Simulation

Abstract: Aiming at the shortcomings of ship fire training in real environment and the advantages and application of virtual reality technology in education and training, the virtual fire training system of ship based on head mount display (HMD) is developed. The system is developed using the Unity 3D Virtual Reality Development Engine as a platform, using client / server mode, supporting multi-person cooperative operation, and running the terminal for HTC Vive virtual reality hardware. The system combines the fire diffuser mechanism, the water shooting hydrodynamic equation and the particle system; completes the model establishment and visualization process, and improves …

Systematic Error Analysis Based On Hardware-In-The-Loop Simulation Environment, Zhang Duo, Manguo Liu, Zhang Xiao, Pingan Liu, Yixuan He

Journal of System Simulation

Abstract: Aiming at the complex and diverse components in the semi-physical simulation environment of a certain type of anti-tank missile, the errors present different types of problems, and a systematic error analysis method based on the environment is proposed. By analyzing the composition characteristics and the error characteristics of the simulation computer, flight motion simulator, target simulator and simulation dedicated interface; the delay error of the simulation computer, the mechanical installation error of the flight motion simulator, the delay error of the target simulator and the transmission error of the simulation dedicated interface are acquired. Furthermore, by comparing the local …

Design And Simulation Of Heterogeneous Magnetron Memristive Chua Circuit, Xiaohong Zhang, Lijuan Wan, Keliu Long

Journal of System Simulation

Abstract: A nonlinear circuit containing two heterogeneous magnetron memristors which based on the three-order classic Chua circuit is designed, its dimensionless fifth-order mathematical model is proposed. Due to the difference in the design of the characteristic equation of the two magnetron memristors, their positions form a symmetrical structure with respect to the capacitor. The existence of chaotic properties is proved by analyzing the stability of the system equilibrium point and Lyapunov exponents. The model of five-order heterogeneous memristive Chua system and two heterogeneous magnetron memristors are implemented by Multisim. Numerical calculation and experimental results show that heterogeneous magnetron memristive Chua …