Engineering Commons^™

Research On Modeling Of Weapons System Of Systems Evaluation, Jianjun Cao, Haizhou Ma, Delong Jiang

Journal of System Simulation

Abstract: The evaluation of weapons system of systems is an important link in the development of weapons system of systems. It is in the development stage and lacks complete theoretical system and systemic research achievement. Based on improving tentatively the evaluation indexes in evaluation of weapons system of systems, the new strategy of evaluation analysis was proposed by fuzzy mathematics theory. It did not only consider adequately the influence by the evaluation objective, but also built the models of comprehensive evaluation for each link in evaluation process and designed the flow chart for programming. It provided a systemic feasibility …

Research Of Maglev Train Dynamics Simulation Based On Levitation Control Algorithm, Songqi Li, Kunlun Zhang

Journal of System Simulation

Abstract: A dynamics model for a whole section of the EMS maglev train was built based on MATLAB, the model described the relationship among body - levitation frame - elastic track and had four degrees of freedom. It simulated and analyzed the vehicle-track coupled vibration dynamic behavior while the vehicle passing the elastic tracks at 200 km/h, using three different kinds of control algorithms respectively. The simulation results show that under the condition of a certain speed and fixed vehicle-track physical parameters, the dynamics behaviors of body - levitation frame - track are obviously different by adopting different control algorithm, …

Research On 3g Emergency Communication Network Simulation System Based On Performance Evaluation, Tang Hong, Yang Guang, Chuan Xu, Wenguang Tang

Journal of System Simulation

Abstract: According to the application requirements of simulation evaluation about Emergency communication network performance when making emergency response plans and simulating exercises, the communication network simulation models were analyzed for 3G emergency communication systems. Then a simulation system of 3G emergency communication networks was designed and implemented with system-level dynamic simulation technology in order to perform the real-time simulation and provide the related performance parameters for network performance evaluation of 3G mobile emergency communication systems under different scenarios. Experiment results show that the system proves its high efficiency and validity.

Embedded Power Optimization Method Based On User Behavior, Wang Hai, Gao Ling, Dongqi Chen, Ren Jie

Journal of System Simulation

Abstract: In recent years, with the rapid development of embedded device represented by mobile phone and tablet computer, low power technology has been one of the hotspots in the embedded research field. Because the battery capacity of embedded device is limited due to its restricted volume and weight, there are often users suffering the problem that their phone battery being dead. There are many research directions in embedded low power field at present. The relationship between low power and user behavior recognition was aimed, which started with recognizing user behavior using machine learning and then obtains the user’s daily usage …

Simulation And Exergy Analysis Of Aircraft Fuel System, Liu Shuang, Wanyan Xiaoru, Damin Zhuang

Journal of System Simulation

Abstract: Based on a certain type of aircraft fuel system design for the prototype, and characterized by the self supplied fuel network, the mathematical models of the main components were built. Using the modular structure method, the Simulink/Matlab was adopted for building the simulation modules of various components and forming the whole simulation system. According to the simulation calculation, the flow, pressure and temperature for each node of the fuel system were obtained, and the effects of several parameters of heat exchangers on its exergy losses were analyzed. The present study provides a new method and idea for the modeling …

A Scoring Model To Evaluate Offshore Oil Projects: Case Of Eni And Mellitah Oil & Gas, Abdulhakim Giadedi

Dissertations and Theses

Offshore oil projects have many different and unique characteristics, such as larger project size, higher number of scopes, and higher complexity. In fact, offshore oil projects described as mega projects are ones that require significant assessment and acquisition methods in order to reduce risks and failures. Traditionally, cash flow analysis and return on investment are the most known factors to evaluate offshore oil projects. However, there are several other internal and external factors that affect the overall performance of offshore oil projects. A comprehensive approach and advanced tools are required to evaluate these factors that can have a significant impact …

Analog Statistical Design For Manufacturability, Yu-Shan Wang

Dissertations and Theses

The manufacturing yield, overkill, and defect level limit the feasibility of analog circuits in SoCs. The conventional method of handling process and environmental variation is to assign a design margin such that the design meets specifications at several processes and environmental corners. However, checking only extreme corners limits performance in comparison to the more rigorous statistical approach of the computing manufacturing and quality figure of merit. The statistical approach requires transistor-level simulation of hundreds or even thousands of samples, not just a few corners, and thus is very time consuming.

This research offers a method for reducing the time required …

An Outline Of The Roles Of The Principle Participants In The ‘Traditional’ Construction Procurement Process, Tony Cunningham

Other Resources

The construction industry is a complex and fragmented industry comprised of a wide range of participants. This study examines the roles of principle participants in the process, and focusses on the role of the client, the contracting organisation, the architect and design and management professionals including the quantity surveyor. Other parties who are indirectly involved in the industry including the regulatory authorities, the wider property sector and end users are commented upon, but are not examined in great detail. The study has identified that effective teamwork is crucial to successfully achieving the goals of delivering the project safely, to the …

Theoretical And Experimental Validation Of A Cubesat's L-Band Communication System, Evangelos Mastrogiannis

Dissertations and Theses

An L-band uplink communication system was designed and validated in the lab for a CubeSat satellite operating in low Earth orbit (LEO). This paper investigates communication link analysis, discusses the design strategy for an inexpensive CubeSat receiver operating in L-band with a moderate power Earth station transmitter, and validates the link budget with prototype hardware using an anechoic chamber.

A receiver's required carrier-to-noise ratio (CNR) establishes the basis for a link budget. The requirement for a digital communication link is set by the bit-error-rate (BER) requirement of a chosen communication protocol which is inversely related to the energy per bit …

Supervised Learning-Based Fast, Stealthy, And Active Nat Device Identification Using Port Response Patterns, Seungwoon Lee, Si Jung Kim, Jungtae Lee, Byeong-Hee Roh

College of Engineering Faculty Research

Although network address translation (NAT) provides various advantages, it may cause potential threats to network operations. For network administrators to operate networks effectively and securely, it may be necessary to verify whether an assigned IP address is using NAT or not. In this paper, we propose a supervised learning-based active NAT device (NATD) identification using port response patterns. The proposed model utilizes the asymmetric port response patterns between NATD and non-NATD. In addition, to reduce the time and to solve the security issue that supervised learning approaches exhibit, we propose a fast and stealthy NATD identification method. The proposed method …

Research On Interoperability Between Tena And Certain Command & Control System, Zhihua Dong, Yuanchang Zhu, Yanqiang Di, Xianguo Meng

Journal of System Simulation

Abstract: The heterogeneity prevents systems from the interoperability between C2 system and TENA for inter-connection in test community. Message Transfer Service contains End-to-End deployment mode and Cross-Network deployment mode, respectively there being two Inter-architecture with TENA system. Gateway can be designed to be single-threaded or multi-threaded. From the perspective of interoperability Gateway realizes the interoperability between communication protocols, object models and supporting services. Cooperation mechanism is designed to achieve the interoperability between the communication mechanism of pull mode in TENA and in C2P; meta-model of Message with OWL, and the object model interoperability is realized through model conversion; self-defined …

Error Correction Methods In Numerical Simulation For Unilateral Constraint Dynamics, Haitao Gao, Yali Han, Youxiong Xu, Songqing Zhu, Zailuo Wu

Journal of System Simulation

Abstract: Aiming at problem of calculation errors and constraint violation in numerical simulation for dynamics of unilateral constraint such as contact and collision, the error projection correction methods were put forward. On the basis of dynamical behavior of unilateral constraint described by linear programming model, mixed linear complementarity dynamics was built. Numerical simulation methods for the mixed linear complementarity dynamics were derived. In order to reduce calculation error and constraint violation caused by this error in the numerical simulation, an error correction method was built for correcting position and velocity error of numerical solution on the base of bilateral …

Improved Strategy To Reduce Common-Mode Voltage For Matrix Converter, Weizhang Song, Li Xi, Minyuan Li, Yanru Zhong

Journal of System Simulation

Abstract: Aiming at the large instantaneous common-mode voltage in traditional space vector modulation strategy for two-stage matrix converter (TSMC), on the basis of analyzing the laws of common-mode voltage, an improved modulation strategy to reduce common-mode voltage was proposed. To suppress common-mode voltage effectively, in this strategy, the rectification stage sector was subdivided into twelve sectors from six sectors, according to the sector of the reference current vector and dc-side voltage, the switching points of inverter stage were redefined and reallocated, and zero vector of inverter was selected and distributed reasonably, instantaneous maximum value of common-mode voltage was reduced to …

Research On Motion Control Technology Of Virtual Human’S Lower Limb Based On Optical Motion Capture Data, Liang Feng, Zhili Zhang, Xiangyang Li, Zhibo Tang, Ma Chao

Journal of System Simulation

Abstract: As passive-optical motion capture equipment could only capture the motion information of human’s key joints, a simplified skeleton structure model of virtual human was introduced; and then the error sources of motion data of virtual human were analyzed according to the acquisition process of optical motion capture data based on the skeleton structure model. Focusing on the problem of poor continuity of motion process of virtual human’s lower limb caused by continuity deficiency of motion capture data, a motion control method was proposed to strengthen the control of motion process of virtual human, which included data smoothing of motion …

Servo Load Simulator Based On Improved Wavelet Neural Network, Wang Chao, Rongzhong Liu, Yuanlong Hou, Gao Qiang, Wang Li

Journal of System Simulation

Abstract: In order to prevent the surplus torque of servo load simulator which had influence in the performance of the torque load, an intelligent controller was put forward based on the improved self-learning functional expansion wavelet neural network. The Bang-Bang control is used when the error is big, and if the error is small, function expansion based on wavelet neural network and fuzzy compensation control is used; At the same time, the improved differential evolution algorithm is for estimating the parameters of the controller. Considering the computational complexity and performance of the control system, the number of hidden neurons …

Controller Design For Hypersonic Vehicle Based On Kalman Filter, Tao Chao, Jianliang Ai

Journal of System Simulation

Abstract: For a generic hypersonic vehicle with unstable longitudinal and lateral-directional mode, considering the three dimensional turbulence and their gradient, all states linear dynamic equations were established. All states H_∞ feedback control was proposed based on the discrete Kalman filter when three dimensional turbulence and system measurement noise were taken into consideration. In this way, state estimation created by the Kalman filter to the H_∞ controller was delivered. This method could guarantee the robustness when external atmospheric turbulence and itself parameter matrices perturbation caused by the flight condition variation existed. The results show that for both the nominal …

Modeling And Simulation Of Urination Assist System Driven By Ultrasonic-Vaporized Steam, Li Xiao, Huaizhou Zhou, Zhichao Shi, Ting Guan, Yuansong Xiao

Journal of System Simulation

Abstract: Aiming at the problem of assisting the neurogenic bladder micturating, a novel urination assist system driven by ultrasonic-vaporized steam was proposed. The mathematical model of the multi-field coupling relation between the external ultrasonic controlling parameters and the urine flow rate of urinary bladder was built using ultrasonics, thermodynamics and fluid mechanics theories. The simulation analysis of the influence of the controlling parameters on the urine flow rate performance of the system was conducted. The results show that the urine flow rate are mainly affected by the ultrasonic sound intensity, frequency, radiation area and time, as well as the system …

Analysis The Nano Contact Force Of Single Crystal Copper In Contact And Separation Processes, Jianmeng Huang, Jingjing Chen

Journal of System Simulation

Abstract: On the basis of considering the adhesive force and copper substrate elastic-plastic deformation, the contact and separation processes between diamond indenter and copper substrate are simulated based on EAM and Morse potentials and Verlet algorithm. The results show that, when diamond indenter approaches slowly to copper substrate during the contact process, some atoms at the top level of substrate happened “snap back” phenomenon significantly due to the gravity became the main interaction force. Furthermore, it can be seen that the contact force and the accumulation phenomenon of dislocation atoms increase gradually with the increment of diamond displacements. During in …

Research On Simulation Of Manufacturing Grid Resource Allocation Based On Scale Free Network, Xiangbin Zhang, Yanyan Li

Journal of System Simulation

Abstract: In order to study the variation of resource allocation efficiency in manufacturing grid, the manufacturing grid resource allocation network model was established based on scale free network theory taking the manufacturing resource characteristics such as distribution and diversity into account. By calculation of the statistical indicators of complex networks and attribute functions, the appropriate resource allocation scheme was selected to realize global optimal resources allocation. Using this model and evaluation index of resource allocation, the variation rule was figured out that explained how resource allocation efficiency varied with structural evolution of manufacturing grid through analyzing the data from simulation …

Man-Machine Coordinated Intelligent Flight Path Planning Algorithm, Ren Peng, Xiaoguang Gao

Journal of System Simulation

Abstract: Man-machine coordinated flight path planning of UAV low-altitude penetration is a key technology achieving manned and unmanned aerial vehicles cooperative combat. The algorithm of man-machine coordinated intelligent flight path planning was proposed, combining artificial auxiliary decision with novel intelligence algorithm, a chromosome integer code with changeable length based on angle was used to represent flight path. Human’s wisdom and experience could make up for the lack of intelligence algorithm. In the most dangerous environment, it made the best possible use of the human brain to guide solution procedures of the flight path planning on pop-up threats. A …

Research On Model And Simulation Of Bullwhip Effect In Supply Chain Based On Pid, Hebing Zhang

Journal of System Simulation

Abstract: Under the uncertainty of market demand, the method exponential smoothing was utilized to forecast the real demand, coupled with information sharing and PID control theory. Four kinds of ordering models were established under different backgrounds, including the ones with or without information sharing, further on, based on the PID control respectively. A comparing of values was obtained by the simulation examples of corresponding bullwhip effect. Through the research, it is found the impact of PID control is better than that of information sharing on weakening the bullwhip effect, which is fit for the condition without information sharing. PID …

Research On Component-Based Modeling Of Combat Simulation Entity, Guohong Du, Wei Wei, Luyao Li

Journal of System Simulation

Abstract: According to the fact that combat simulation entity models built by traditional modeling method lack of standardization and reusability, based on analysis and induction of combat simulation entity factors, component-based modeling method of combat simulation entity was brought forward. Meanwhile, entity management mechanism of using “scheme-unit-entity-component” and model interaction mechanism of message-derived, event-subscribed and event-dispatched were discussed. The component-based modeling method will provide technique support to build excellent combat simulation entity model and standardizing the development of combat simulation entity model to avoid low-level duplication.

Control Law Research And Design Of Large Commercial Civil Aircraft For Oscillatory Failure, Ziyu Yao, Jianliang Ai

Journal of System Simulation

Abstract: The oscillatory failure often occurs because of the electronic equipment failure or the structure vibration in the modern commercial civil aircraft. The solution to the problem needs lots of sensors and control controllers and it make the control structure complex and leads to further fault. The mathematical model including the servo loop was built and the analytical redundancy was used for the fault detection. A combined control law was designed based on the detection result that was the residual of the servo signal and the state quantities. The design improves the control structure of the EFCS feedforward channel …

Modeling And Simulation For Target Tracking System Based On Dual-Pan-Tilt Camera, Kaishun Xiahou, Shanxing Chen, Yilin Wu

Journal of System Simulation

Abstract: Mathematical model of each component of target tracking system based on dual-pan-tilt camera was established. The rotation angles both in horizontal and vertical direction of each pan-tilt and the relative position of two cameras were adopted to estimate the real-time position of moving target with Extended Kalman Filter (EKF) tracking algorithm. A new real-time calibration method for pan-tilt camera was proposed to deal with the calibration problem that the external parameters of camera changes as the pan-tilt rotates in the process of camera modeling. In addition, the target’s image feature, extracted from the projected point on the camera image …

Attribute Reduction Algorithm On Balancing Profit And Risk, Dexing Wang, Jielong Xu, Hongchun Yuan

Journal of System Simulation

Abstract: Usually it is taken for granted to achieve the maximal profit at the cost of the minimal risk. It is an important problem of how to balance profit and risk, considering introducing profit and risk to attribute reduction so as to find practical algorithms in decision-making process. A decision-theoretic model was built, which could balance profit and risk combining with decision-theoretic rough set model and minimum risk of Bayes decision and find optimal combinations of risk in a certain level of expected profit, then a heuristic algorithm of attribute reduction was proposed, which took the function of balancing …

Immediate Effects Of Dynamic Lycra® Orthosis On Sitting To Standing Ability Children With Cerebral Palsy / Ida Hasni Shaari, Ida Hasn Shaari

Student Works (2020-2029)

Children with Cerebral Palsy (CP) are highly exposed to postural mal-alignment which interrupt their functional movement pattern and the ability to attain certain functional activities, like walking and Children with Cerebral Palsy (CP) are highly exposed to postural mal-alignment which interrupt their functional movement pattern and the ability to attain certain functional activities, like walking and sitting-to-standing motion (STS). Orthoses are commonly prescribed to give good posture in these children. Yet, none of the orthoses has been found to be suitable in addressing trunkpelvis alignment in children with cerebral palsy, to enhance their STS performance. Therefore, this study was conducted …

Optimal Distribution System Reconfiguration Incorporating Distributed Generation Based On Simplified Network Approach, Mohammad Al Samman

Student Works (2020-2029)

Network Reconfiguration (NR) and Distributed Generation (DG) are well-accepted strategies to minimize power loss and voltage deviation in the Electrical Distribution Network (EDN). Since the NR problem contains a huge combinational search space, most researchers applied meta-heuristic methods to attain optimal NR solution. However, meta-heuristic methods do not always guarantee optimal solution and furthermore they consume huge processing time. This occurs mainly due to (1) random solution’s initialization and (2) the verification of solution in each iteration to fulfill the operation constraints during the optimization process. Besides, solving the NR problem simultaneously with DG placement and sizing increases the computational …

Research Progress On War Complex System Of Systems Modeling Based On Complex Network, Ma Li, Mingzhi Zhang

Journal of System Simulation

Abstract: The crucial issue of war complex system of systems (SoS) modeling is to represent the complex coupling and interaction among components of SoS based on networks. The complex network provides new means of SoS modeling. The Characteristics of complex network suitable to SoS modeling were introduced, and two kinds of general method for SOS modeling based on complex network were summed up. The research progress on operational SoS modeling was elaborated from the four aspects of networked description of SoS, modeling algorithm of SoS network, evaluation for SoS based on complex network and the combination of complex network and …

Modelingrandom Kelvin Cell Micro-Structure For Open-Cell Foam And Its Application On Compression Response Of Open-Cell Aluminum Foam, Minju Qi, Guangfa Gao

Journal of System Simulation

Abstract: It is very difficult to model an applicable microstructure for the open cell foams. Using the Python scripting language and the commercial code ABAQUS, the structures for regular Kelvin cell, regular Kelvin open cell foams and random Kelvin open cell foams were designed and modeled automatically. The methodology for modeling, the design and implement for the key algorithms in the process of modeling were presented. For the open cell Aluminum foam, the regular Kelvin cell open cell model and the random Kelvin cell open cell foams model were developed, respectively, and the mechanical responses of them under quasi-static …

Study On Personalized Data Driven Method Of Surface Of 3d Liver Models, Guodong Chen, Jiexiong Wang, Chen Yi

Journal of System Simulation

Abstract: The personalization of 3D liver models and the acquisition of liver models with high precision are two key technologies in virtual surgery systems. A personalized data-driven method aiming at the problems of time efficiency and precision of liver models was proposed. The liver model with high precision from previous research achievements and personal CT datasets were processed respectively, and then some feature points were marked on both the model and the CT datasets. The PCA algorithm was used to get the initial matching, the ICP algorithm was used to get the matching of the feature points, and then an …