Computer Engineering Commons^™

Behavior Recognition Combining Regional Optical Flow Features And Temporal Templates, Manyi Wang, Yaling Song, Li Yu, Zhang Liang

Journal of System Simulation

Abstract: A method was proposed to recognize human behavior, which combined the wavelet moments of temporal templates and the speed feature by optical flow. The wavelet moments are not only rotation, translation and scale invariance, but also have the multi-scale characteristics of wavelet. The shape feature of the motion history image and motion energy image can be described. To simple motions, it's effectively, but it can't present the speed information. Regional optical flow was calculated to describe the direction and amplitude features of motion by Lucas-Kanade algorithm. It could make up shortcomings of wavelet moment without speed information. Being …

Temporal Heterogeneous Interaction Graph Embedding For Next-Item Recommendation, Yugang Ji, Mingyang Yin, Yuan Fang, Hongxia Yang, Xiangwei Wang, Tianrui Jia, Chuan Shi

Research Collection School Of Computing and Information Systems

In the scenario of next-item recommendation, previous methods attempt to model user preferences by capturing the evolution of sequential interactions. However, their sequential expression is often limited, without modeling complex dynamics that short-term demands can often be influenced by long-term habits. Moreover, few of them take into account the heterogeneous types of interaction between users and items. In this paper, we model such complex data as a Temporal Heterogeneous Interaction Graph (THIG) and learn both user and item embeddings on THIGs to address next-item recommendation. The main challenges involve two aspects: the complex dynamics and rich heterogeneity of interactions. We …

Querying Recurrent Convoys Over Trajectory Data, Munkh-Erdene Yadamjav, Zhifeng Bao, Baihua Zheng, Farhana M. Choudhury, Hanan Samet

Research Collection School Of Computing and Information Systems

Moving objects equipped with location-positioning devices continuously generate a large amount of spatio-temporal trajectory data. An interesting finding over a trajectory stream is a group of objects that are travelling together for a certain period of time. Existing studies on mining co-moving objects do not consider an important correlation between co-moving objects, which is the reoccurrence of the movement pattern. In this study, we define a problem of finding recurrent pattern of co-moving objects from streaming trajectories and propose an efficient solution that enables us to discover recent co-moving object patterns repeated within a given time period. Experimental results on …

Low Complexity Method Based On Fc-Ce-Slm For Papr Reduction In Ofdm System, Ce Ji, Lijuan Wang

Journal of System Simulation

Abstract: Selected mapping (SLM) algorithm uses Cross Entropy (CE) algorithm to get the most optimal sign sequence so that SLM can make the effect of PAPR Reduction achieve optimum. However, it needs too many times iterative computations, so it will increase the complexity of the algorithm. In order to solve this problem, a fast convergence factor in the CE-SLM algorithm was introduced to make the sampling probability converge to 0 or 1 quickly in the system, which reduced the iterative times of getting the optimal sign sequence. Computer simulation results show that the approved algorithm reduces the iterative times of …

Traffic Simulation Of Elementary And Middle School's Gate Road During Student Departing School Based On Ca Model, Mingbao Pang, Chen Jing, Yang Min

Journal of System Simulation

Abstract: The simulation problem of student departing school to the traffic flow of elementary and middle school's gate road was studied by using a cellular automaton model. Based on STNS (symmetric two-lane Nagel-Schreckenberg) model, a cellular automaton model on the interference road section of elementary and middle school's gate during student departure school was established. The traffic flow characteristics of the road during student departure school time were discussed via the simulation experiment. The effects were analyzed how the proportion of students departing school by private cars, the proportion of students departing school by school buses, and the …

Simulation Research On Influence Of Blood Flow On Heating During Hifu Treatment, Suqin Dai, Shengyou Qian, Yaosheng Gui, Xiao Sheng

Journal of System Simulation

Abstract: When blood vessel exists in the tumor tissue, and its boundary portion close to the vessel will be strongly influenced by the cooling effect of the blood vessel. This influence will lead to the incomplete cancer treatment. To study the influence of blood flow on heating towards the above situation, concave spherical transducer was used as the heat source, and sound intensity distribution was obtained by Rayleigh integral. Pennes equation was solved with finite difference method, then the dose distribution was calculated to determine the thermal damage degree of tissue using quantitative relationship between the heating time and temperature. …

Hardware-In-The-Loop Test-Bed For Testing Of Lunar Rover Gnc Based On Vision-In-The-Loop, Zhiping Li, Zhang Zhi, Jianxin Chen, Wang Lei, Hehua Ju

Journal of System Simulation

Abstract: A hardware-in-the-loop and vision-in-the-loop test-bed for the testing of the lunar rover guide navigation control (GNC) subsystem was introduced. The composition of the test-bed and its dataflow were delicately designed. Then the vision-in-the-loop concept was designed. To overcome the problem of matching between the hazard-camera's focus and the images' distortion parameters, the distortion computation on the edge of the image pixels was ignored. Furthermore, to fulfill the closed-loop testing, the stereo vision function was accomplished by using multiple processes that made the images rapidly generated and the cameras' position and attitude parameters were supplied from rover's dynamics. Many …

Balanced Bee Colony Algorithm Based On Fitness Euclidean-Distance Ratio, Zhang Ming, Tian Na, Zhicheng Ji

Journal of System Simulation

Abstract: According to the power exploration and poor exploitation ability of artificial bee colony (ABC), a balanced bee colony (FER-ABC) was proposed. This algorithm modified the search equation based on “fitness Euclidean-distance ratio” and differential algorithm (DE). The FER strategy is useful for multi-optimization and the DE is beneficial to single- optimization. In order to exploit the advantages to full, a new search structure was proposed which balanced the exploitation and exploration. For continuous problems, the simulations on twelve benchmark functions indicate that this FER-ABC algorithm can improve the accuracy effectively and increase the convergence rate apparently. For the discrete …

Digital Water Depth Processing For Multibeam Based On Average Slope Of Terrain, Jiacheng Yu, Xueqiang Xu

Journal of System Simulation

Abstract: According to the characteristic of multibeam bathymetry in which measurement depth is influenced by terrain, revision algorithm was proposed based on average slope along the horizontal and vertical terrain. Five depth revision factors were obtained, and a depth smooth template was designed. The initial scan depth data were revised by the 5 revision factors, and then the revised depth data were filtered by the template. Simulation results show that, the depth of measurement error can be reduced greatly after revision, the designed template relative to the conventional Gauss template has higher smooth precision, more adapted to the water …

Research Of Noise Mitigation Method Based On Dspwvd-Tfpf In Communication System, Lingdong Su, Mingyue Zhai

Journal of System Simulation

Abstract: In the case of low SNR, the quality of the communication system will be decreased and the traditional TFPF on time-frequency clustering and noise suppression will descend. In order to overcome these, a new family of TF distribution, namely, the joint directionally smoothing Wigner-Ville distribution was presented to achieve instantaneous frequency estimation. This new TF distributions is based on the definition of the directionally smoothed pseudo Wigner-Ville distribution (DSPWVD) and point wise adaptive weight averaging of a bank of DSPWVD with different directions. The simulation shows that at low SNR, compared to traditional TFPF, DSPWVD-TFPF algorithm can better …

Construction Of Virtual Atmospheric Environment Based On Mm5 And Sedris, Lianlei Lin, Ding Wei

Journal of System Simulation

Abstract: The new virtual test for virtual atmosphere environment puts forward higher requirements, such as providing complex atmospheric environment which includes a variety of atmospheric parameters and improving usability and reusability of atmospheric environment data. A method to construct virtual atmospheric environment based on MM5 and SEDRIS was proposed which met the above demands. The original data of complex atmospheric environment in any region and scale was generated by using MM5 model. According to the characteristics as well as the dynamic relationship between time and space of grid of atmospheric data, SEDRIS was selected to regulate appropriate DRM class, SRF …

Study On Equipment Domain Ontology Construction For Integration Of Data Semantics, Li Kang, Xinming Li, Liu Dong

Journal of System Simulation

Abstract: Equipment domain ontology could accurately describe definition of concepts in the field and the relationships between the concepts, which is foundation and prerequisite in semantic integration of equipment data. With the analysis of the existing methods, a semi-automatic domain ontology construction method was proposed. The top-level domain ontology was built under the standard of authoritative documents in the equipment field. An initial partial ontology was generated from the equipment database by mapping. The ontology was standardized through mapping process. The results of the experiment show that this method can build equipment domain ontology which provides a unified global …

Large Eddy Simulation Of Effect Of Geometric Parameters On Low Pressure Of Turbulent Flow Over Gate Slot, Shihua He, Lixiang Zhang

Journal of System Simulation

Abstract: The turbulent flow over the hydraulic plane gate slot was studied using large eddy simulation method. The effects of geometric parameters including width-to-depth ratio, stagger ratio, slope ratio and fillet ratio on hydraulic characteristics within and near the gate slot were simulated systematically. According to the vulnerable cavitation locations of the flow over the slot, the pressure distributions in swirl area and the separation zone at the rear of downstream corner of the slot were investigated emphatically. The results show that the effects of width-to-depth ratios and stagger ratios on the pressure distribution of the flow are significantly. …

Launch Dynamic Characteristics Simulation Analysis Of Vehicular Gatling Gun In Different Road Surface, Junnuo Zhang, Ruilin Wang, Li Tao, Binbin Hua

Journal of System Simulation

Abstract: To study the influence of firing accuracy on a certain vehicular Gatling gun in different road surface, a rigid-flexible coupling multi-body dynamic simulation model was established based on virtual prototyping technology. Considering the interaction relations between the tires and road surface, vehicle and machine gun, the vehicle vibration characteristics and the muzzle response characteristics and vertical-target dispersion were obtained by analyzing the machine gun system in different road surface. The influence of road surface on fire accuracy was demonstrated by contrasting and analyzing the simulation curves. The study results have provided a theoretical support and direction …

Design Of Iaas Mode “Cloud Training” System, Zhijia Chen, Yuanchang Zhu, Yanqiang Di, Shaochong Feng

Journal of System Simulation

Abstract: There are some problems in equipment web simulating training, including poor sense of reality, low efficiency of training and high difficulty of management. To solve those problems, Infrastructure as a Service mode “cloud training” was proposed. The architecture and operation flow were explained in detail and the key technologies of “cloud training” were focused on. By GPU virtualization technology, the problem of client 3D image processing capability was solved. According to the characters of simulation training, the user requirement model was established. Fuzzy algorithm was introduced to realize resource dynamic scheduling. To assure the stability and reliability, …

Decision Strategy Models Of Merge Influence Area For Outside Vehicles Based On Vehicle-Vehicle Communication, Xiaofang Yang, Guo Qian, Fu Qiang

Journal of System Simulation

Abstract: In the on-ramp merging area, appropriate driving decisions should be made by observing the running environment and estimating the driving characteristics of the surrounding vehicles, which usually led to the inordinate traffic flow. To solve this problem, the decision strategy models were built for vehicles in the on-ramp merging area, and the operating rules for the new decision strategy were updated. Furthermore, the space-time trajectory, the lane changing in merging and upstream area and the average speed in the two different circumstances were analyzed by numerical experiments. The results show that in the condition of vehicle-vehicle communication environment, …

Study On Simulation Of Turning Burr Formation Based On Finite Element Method, Yunming Zhu, Jingui Huang, Guicheng Wang, Chen Yun

Journal of System Simulation

Abstract: According to the relative motion of tool and workpiece, a new mechanical-thermal coupling finite element model of turning burr formation was established. It adopted supporting plate method to eliminate the influence of workpiece deformation which remained on the workpiece side. Operational efficiency improved greatly under this model. Based on the analysis of simulation results, it is discovered that there are both bending deflection and partly cutting occurred on cutting layer material. AISI1045 steel turning experiment was conducted, it is found that the results of simulation are close to the experimental. The model provides an effective way for analyzing the …

Research Of Marshalling Yard Dispersion Based On Simulation In Container Terminal, Yu Hang, Le Meilong

Journal of System Simulation

Abstract: As development of the precision management in the container terminal, close attention was paid to the research on the optimization of the marshalling yard template. The new concept called the yard dispersion in the container yard template was proposed and the professional simulation software Flexsim-CT was used to build a container handling simulation model which includes berth, quay crane, yard scheduling, yard crane, and trucks. The impact of the different yard dispersion on the total handling time and the efficiency of the quay crane under varying service burden was analyzed. The case study combines the simulation model with …

Optimization Design For A New Type Throttle Valve Of Managed Pressure Drilling Based On Response Surface Methodology, Guorong Wang, Chu Fei, Hongkang Fan, Siyu Tao, Zhu Hao, Jiang Long

Journal of System Simulation

Abstract: The Kriging response surface of single parameter and double parameters versus mass loss of valve spool about bonnet length, bonnet external radius and chamber inner radius of a new type throttle valve used in Managed Pressure Drilling was carried out by using CFX and ANSYS-Design Exploration. The results show that these dimensions have significant influence on erosion mass loss of valve spool. In order to improve the anti-erosion ability of the spool and enhance the service life of the whole valve, the multi-objective genetic algorithm was used for dimensional optimization design of the mentioned variables. After optimization …

The Entanglement Of Influential Technology Channels In Practice And Design, Ciarán O'Leary

Doctoral

Design for academic practice is an important phenomenon in Higher Education. This is the practice through which informal, non-professional designers operating in a variety of roles in academic institutions carry out the design of systems, resources, activities and processes that are intended to enhance academic practice. Despite its importance, the area has not received sufficient attention in studies of academic practice, quality enhancement and digital transformation. This thesis argues that the absence of insight into how designers for academic practice engage with digital technology in their design practice contributes to the mismatch between the ambitions for digital transformation in higher …

Detection Of Software Vulnerability Communication In Expert Social Media Channels: A Data-Driven Approach, Andrei Lima Queiroz

Doctoral

Conceptually, a vulnerability is: "A flaw or weakness in a system’s design, implementation,or operation and management that could be exploited to violate the system’s security policy".Some of these flaws can go undetected and exploited for long periods of time after soft-ware release. Although some software providers are making efforts to avoid this situ-ation, inevitability, users are still exposed to vulnerabilities that allow criminal hackersto take advantage. These vulnerabilities are constantly discussed in specialised forumson social media. Therefore, from a cyber security standpoint, the information found inthese places can be used for countermeasures actions against malicious exploitation ofsoftware. However, manual inspection …

Efficient Fine-Grained Data Sharing Mechanism For Electronic Medical Record Systems With Mobile Devices, Hui Ma, Rui Zhang, Guomin Yang, Zishuai Zong, Kai He, Yuting Xiao

Research Collection School Of Computing and Information Systems

Sharing digital medical records on public cloud storage via mobile devices facilitates patients (doctors) to get (offer) medical treatment of high quality and efficiency. However, challenges such as data privacy protection, flexible data sharing, efficient authority delegation, computation efficiency optimization, are remaining toward achieving practical fine-grained access control in the Electronic Medical Record (EMR) system. In this work, we propose an innovative access control model and a fine-grained data sharing mechanism for EMR, which simultaneously achieves the above-mentioned features and is suitable for resource-constrained mobile devices. In the model, complex computation is outsourced to public cloud servers, leaving almost no …

Hybrid Deep Neural Networks For Mining Heterogeneous Data, Xiurui Hou

Dissertations

In the era of big data, the rapidly growing flood of data represents an immense opportunity. New computational methods are desired to fully leverage the potential that exists within massive structured and unstructured data. However, decision-makers are often confronted with multiple diverse heterogeneous data sources. The heterogeneity includes different data types, different granularities, and different dimensions, posing a fundamental challenge in many applications. This dissertation focuses on designing hybrid deep neural networks for modeling various kinds of data heterogeneity.

The first part of this dissertation concerns modeling diverse data types, the first kind of data heterogeneity. Specifically, image data and …

Live Media Production: Multicast Optimization And Visibility For Clos Fabric In Media Data Centers, Ammar Latif

Dissertations

Media production data centers are undergoing a major architectural shift to introduce digitization concepts to media creation and media processing workflows. Content companies such as NBC Universal, CBS/Viacom and Disney are modernizing their workflows to take advantage of the flexibility of IP and virtualization.

In these new environments, multicast is utilized to provide point-to-multi-point communications. In order to build point-to-multi-point trees, Multicast has an established set of control protocols such as IGMP and PIM. The existing multicast protocols do not optimize multicast tree formation for maximizing network throughput which lead to decreased fabric utilization and decreased total number of admitted …

Energy And Performance-Optimized Scheduling Of Tasks In Distributed Cloud And Edge Computing Systems, Haitao Yuan

Dissertations

Infrastructure resources in distributed cloud data centers (CDCs) are shared by heterogeneous applications in a high-performance and cost-effective way. Edge computing has emerged as a new paradigm to provide access to computing capacities in end devices. Yet it suffers from such problems as load imbalance, long scheduling time, and limited power of its edge nodes. Therefore, intelligent task scheduling in CDCs and edge nodes is critically important to construct energy-efficient cloud and edge computing systems. Current approaches cannot smartly minimize the total cost of CDCs, maximize their profit and improve quality of service (QoS) of tasks because of aperiodic arrival …

Changing The Focus: Worker-Centric Optimization In Human-In-The-Loop Computations, Mohammadreza Esfandiari

Dissertations

A myriad of emerging applications from simple to complex ones involve human cognizance in the computation loop. Using the wisdom of human workers, researchers have solved a variety of problems, termed as “micro-tasks” such as, captcha recognition, sentiment analysis, image categorization, query processing, as well as “complex tasks” that are often collaborative, such as, classifying craters on planetary surfaces, discovering new galaxies (Galaxyzoo), performing text translation. The current view of “humans-in-the-loop” tends to see humans as machines, robots, or low-level agents used or exploited in the service of broader computation goals. This dissertation is developed to shift the focus back …

Towards Practical Homomorphic Encryption And Efficient Implementation, Gyana R. Sahu

Dissertations

Cloud computing has gained significant traction over the past few years and its application continues to soar as evident from its rapid adoption in various industries. One of the major challenges involved in cloud computing services is the security of sensitive information as cloud servers have been often found to be vulnerable to snooping by malicious adversaries. Such data privacy concerns can be addressed to a greater extent by enforcing cryptographic measures. Fully homomorphic encryption (FHE), a special form of public key encryption has emerged as a primary tool in deploying such cryptographic security assurances without sacrificing many of the …

Analyzing And Assisting Patient Decision-Making In Online Health Communities, Mingda Li

Dissertations

In recent years, many users have joined online health communities (OHC) to seek information, suggestions and social support. However, little has been studied about the roles of OHCs in patients' decision-making processes. The aim of this research is to analyze OHC data to better understand patient decision-making processes, and to provide assistance to OHC users in their decision-making.

In order to analyze or assist patients in their decision-making, a novel classification model is designed to identify discussion threads in OHC that are related to decision making. This is achieved by building a two-step combined deep learning model. Empirical evaluation shows …

Toward A Network Controlled Delivery Of Energy, Zhengqi Jiang

Dissertations

The next-generation power grid aims to integrate the recent technological advancements in the information and communications technology into energy distribution and management. Prior research works propose the concept of the digital grid (DG) as means to fulfill the requirements of the next-generation power grid. While there are several approaches to the DG, they all share the use of internet protocol (IP) addresses to identify lines and grid devices but lack of a full integration of core concepts of digital communications into the management on the delivery of energy.

This dissertation discusses the incorporation of the concept of controllable delivery of …

Cyber Social Threats 2020 Workshop Meta-Report: Covid-19, Challenges, Methodological And Ethical Considerations, Ugur Kursuncu, Yelena Mejova, Jeremy Blackburn, Amit Sheth

Publications

Online platforms have been increasingly misused by ill-intentioned actors, affecting our society, often leading to real-world events of social significance. On the other hand, recog-nizing the narratives related to harmful behaviors is challeng-ing due to its complex and sensitive nature. The Cyber SocialThreats Workshop 2020 aimed to stimulate research for thechallenges on methodological and ethical considerations indeveloping novel approaches to analyze online harmful con-versations, concerning social, cultural, emotional, commu-nicative, and linguistic aspects. It provided a forum to bringtogether researchers and practitioners from both academiaand industry in the areas of computational social sciences, so-cial network analysis and mining, natural language process-ing, …