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Computer Forensics-An Essential Element of Modern IT Security

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Journal of Harbin Institute of Technology(New Series) 2014年第6期21卷 5-8页

作者： frank y.W.law K.P.Chow Center for Information Security and Cryptography University of Hong Kong

Computer forensics is the science of obtaining,preserving,and documenting evidence from computers,mobile devices as well as other digital electronic storage *** must be done in a manner designed to preserve the probative value of the evidence and to assure its admissibility in a legal ***,computer forensics is continually evolving as existing technologies progress and new technologies are *** example,digital investigators are required to investigate content on mobile device or data stored at the cloud *** the popularity of computers in everyday life as well as the acceleration of cybercrime rates in recent years,computer forensics is becoming an essential element of modern IT *** paper will cover the development of computer forensics in law enforcement and discuss the development in the latest live forensics skillsets.A number of interested areas of computer forensics will be also highlighted to explain how it can support IT security and civil / criminal investigation.

关键词： computer forensics cybercrime digital evidence

Stochastic DoS Attack Allocation Against Collaborative Estimation in Sensor Networks

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IEEE/CAA Journal of Automatica Sinica 2020年第5期7卷 1225-1234页

作者： ya Zhang lishuang Du frank l.lewis School of Automation Southeast Universityand also with the Key Laboratory of Measurement and Control of Complex Systems of EngineeringMinistry of EducationNanjing 210096China University of Texas at Arlington Research Institute Fort WorthTX 76118 USA IEEE

In this paper,denial of service(DoS)attack management for destroying the collaborative estimation in sensor networks and minimizing attack energy from the attacker perspective is *** the communication channels between sensors and a remote estimator,the attacker chooses some channels to randomly jam DoS attacks to make their packets randomly dropped.A stochastic power allocation approach composed of three steps is ***,the minimum number of channels and the channel set to be attacked are ***,a necessary condition and a sufficient condition on the packet loss probabilities of the channels in the attack set are provided for general and special systems,***,by converting the original coupling nonlinear programming problem to a linear programming problem,a method of searching attack probabilities and power to minimize the attack energy is *** effectiveness of the proposed scheme is verified by simulation examples.

关键词： Attack allocation denial of service(DoS)attack packet loss remote estimation sensor networks

Neural network solution for finite-horizon H-infinity constrained optimal control of nonlinear systems

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控制理论与应用（英文版） 2007年第1期5卷 1-11页

作者： frank l.lEWIS Automation and Robotics Research Institute University of TexasArlington TX 76118USA

In this paper, neural networks are used to approximately solve the finite-horizon constrained input H-infinity state feedback control problem. The method is based on solving a related Hamilton-Jacobi-Isaacs equation of the corresponding finite-horizon zero-sum game. The game value function is approximated by a neural network with time- varying weights. It is shown that the neural network approximation converges uniformly to the game-value function and the resulting almost optimal constrained feedback controller provides closed-loop stability and bounded l2 gain. The result is an almost optimal H-infinity feedback controller with time-varying coefficients that is solved a priori off-line. The effectiveness of the method is shown on the Rotational/Translational Actuator benchmark nonlinear control problem.

关键词： Constrained input system Hamilton-Jacobi-Isaacs H-infinity control Finite-horizon zero-sum games Neural network control

Modeling of the mechano-electrochemical effect at corrosion defect with varied inclinations on oil/gas pipelines

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Petroleum Science 2021年第5期18卷 1520-1529页

作者： Zhu-Wu Zhang Jin-Chang Wang Jiu-Hong Zhang y.frank Cheng College of Chemical Engineering Fuzhou UniversityFuzhou350116FujianChina Department of Mechanical Engineering University of CalgaryCalgaryT2N 1N4AlbertaCanada

A 3-dimensional finite element model was built to determine the effect of inclination angle of a corro sion defect on local mechano-electrochemical(M-E)effect in a simulated soil *** of the high effect of the defect inclination angle on the M-E effect,when the inclination angle is 0°(i.e.,the primary axis of the defect parallel to the longitudinal direction of the pipe),the greate st stress concentration level at the defect can be observed,which is associated with the lowest corrosion potential,the greatest anodic current density and the most serious accelerated localized *** the inclination angle is 90°,the stress concentration level reduces and the corrosion potential becomes less negative,accompanying with the decreased anodic/cathodic current ***,when the ratio(r_(ca))of the primary axial length of the defect to its secondary axial length is 1,the defect inclination does not affect the stress and the electrochemical corrosion rate at the *** the increase of r_(ca),the effect of the defect inclination angle is more apparent.

关键词： Pipelines Corrosion defect assessment Mechano-electrochemical effect Finite element model

Recent Progress in Reinforcement learning and Adaptive Dynamic Programming for Advanced Control Applications

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 18-36页

作者： Ding Wang Ning Gao Derong liu Jinna li frank l.lewis IEEE the Faculty of Information Technology Beijing Key Laboratory of Computational Intelligence and Intelligent SystemBeijing Laboratory of Smart Environmental Protectionand Beijing Institute of Artificial IntelligenceBeijing University of TechnologyBeijing 100124China the School of System Design and Intelligent Manufacturing Southern University of Science and TechnologyShenzhen 518055China the Department of Electrical and Computer Engineering University of Illinois at ChicagoChicago IL 60607 USA the School of Information and Control Engineering Liaoning Petrochemical UniversityFushun 113001China the UTA Research Institute the University of Texas at ArlingtonArlington TX 76118 USA

Reinforcement learning(Rl) has roots in dynamic programming and it is called adaptive/approximate dynamic programming(ADP) within the control community. This paper reviews recent developments in ADP along with Rl and its applications to various advanced control fields. First, the background of the development of ADP is described, emphasizing the significance of regulation and tracking control problems. Some effective offline and online algorithms for ADP/adaptive critic control are displayed, where the main results towards discrete-time systems and continuous-time systems are surveyed, ***, the research progress on adaptive critic control based on the event-triggered framework and under uncertain environment is discussed, respectively, where event-based design, robust stabilization, and game design are reviewed. Moreover, the extensions of ADP for addressing control problems under complex environment attract enormous attention. The ADP architecture is revisited under the perspective of data-driven and Rl frameworks,showing how they promote ADP formulation ***, several typical control applications with respect to Rl and ADP are summarized, particularly in the fields of wastewater treatment processes and power systems, followed by some general prospects for future research. Overall, the comprehensive survey on ADP and Rl for advanced control applications has d emonstrated its remarkable potential within the artificial intelligence era. In addition, it also plays a vital role in promoting environmental protection and industrial intelligence.

关键词： Adaptive dynamic programming(ADP) advanced control complex environment data-driven control event-triggered design intelligent control neural networks nonlinear systems optimal control reinforcement learning(Rl)

Synergistic effects of Nb and Mo on hydrogen-induced cracking of pipeline steels:A combined experimental and numerical study

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Journal of Materials Science & Technology 2023年第27期158卷 156-170页

作者： Shiqi Zhang luming Qi Shilong liu Zhixian Peng y.frank Cheng Feng Huang Jing liu The State Key laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Institute of Advanced Steels and Materials School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Mechanical Engineering University of CalgaryCalgaryAB T2N 1N4Canada Hubei Engineering Technology Research Centre of Marine Materials and Service Safety Wuhan University of Science and TechnologyWuhan 430081China

The synergistic effects of Nb and Mo on hydrogen-induced cracking(HIC)of pipeline steels were studied experimentally and *** results showed that Mo was primarily segregated at grain-boundaries(GBs)or solid-dissolved in the matrix,while most Nb and a small amount of Mo formed dis-persed(Nb,Mo)C nano-precipitates and refined the *** with Nb alloying,the multi-ple additions of Nb-Mo played dual roles in affecting H diffusion:primarily,the H-traps densities such as GBs,precipitates,and solute Mo atoms increased,providing an advantage;however,Mo slightly reduced the H-trapping capacity of precipitates,playing an adverse ***,the beneficial effects far outweighed the adverse effects,thereby reducing H diffusivity and inhibiting crack ***-ally,Nb and Mo hindered crack propagation synergistically as follows:(i)Mo enhanced GB cohesion by repelling H,impeding intergranular cracking and hydrogen-enhanced decohesion(HEDE);(ii)Nb reduced the proportion of3/high-angle grain boundaries,increasing cracking resistance;(iii)(Nb,Mo)C precip-itates impeded H-dislocation interactions,reducing the hydrogen-enhanced localized plasticity(HElP).

关键词： Hydrogen-induced cracking Nb-Mo microalloying Hydrogen permeation Precipitate Pipeline steel

Consensus controller for multi-UAV navigation

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Control Theory and Technology 2018年第2期16卷 110-121页

作者： Patrik KOlARIC Ci CHEN Ankur DAlAl frank l. lEWIS UTA Research Institute University of Texas at Arlington 7300 Jack Newell Bird S Fort Worth TX 76118 U.S.A. School of Automation Guangdong University of Technology Guangdong Key laboratory of loT Information Technology Guangzhou Guangzhou 510006 China State Key laboratory of Synthetical Automation for Process Industries Northeastern University Shenyang Liaoning 110819 China

In this paper, we design consensus algorithms for multiple unmanned aerial vehicles （UAV）. We mainly focus on the control design in the face of measurement noise and propose a position consensus controller based on the sliding mode control by using the distributed UAV information. Within the framework of lyapunov theory, it is shown that all signals in the closed-loop multi- UAV systems are stabilized by the proposed algorithm, while consensus errors are uniformly ultimately bounded. Moreover, for each local UAV, we propose a mechanism to define the trustworthiness, based on which the edge weights are tuned to eliminate negative influence from stubborn agents or agents exposed to extremely noisy measurement. Finally, we develop software for a nano UAV platform, based on which we implement our algorithms to address measurement noises in UAV flight tests. The experimental results validate the effectiveness of the proposed algorithms.

关键词： Consensus control multi-agent system quadrotor lyapunov stability distributed system

Creating a Research Enterprise Framework for Transdisciplinary Networking to Address the Food-Energy-Water Nexus

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Engineering 2022年第4期8卷 95-100页

作者： Jie Zhuang frank E.löffler Gary S.Sayler Department of Biosystems Engineering and Soil Science The University of TennesseeKnoxvilleTN 37996USA Center for Environmental Biotechnology The University of TennesseeKnoxvilleTN 37996USA Institute for a Secure and Sustainable Environment The University of TennesseeKnoxvilleTN 37996USA Department of Microbiology The University of TennesseeKnoxvilleTN 37996USA Department of Civil and Environmental Engineering The University of TennesseeKnoxvilleTN 37996USA Biosciences Division Oak Ridge National LaboratoryOak RidgeTN 37831USA

Urbanization,population growth,and the accelerating consumption of food,energy,and water(FEW)resources bring unprecedented challenges for economic,environmental,and social(EES)*** is imperative to understand the potential impacts of FEW systems on the realization of the United Nation’s Sustainable Development Goals(SDGs)as the world transitions from natural ecosystems to managed ecosystems at an accelerating rate.A major obstacle is the complexity and emergent behavior of FEW systems and associated networks,for which no single discipline can generate a holistic understanding or meaningful *** propose a research enterprise framework for promoting transdisciplinarity and top-down quantification of the interrelationships between FEW and EES *** enterprise efforts would emphasize increasing FEW resource accessibility by improving coordinated interplays across sectors and scales,expanding and diversifying supply-chain networks,and innovating technologies for efficient resource *** framework can guide the development of strategic solutions for diminishing the competition among FEW-consuming sectors in a region or country,and for minimizing existing inequalities in FEW availability when a sustainable development agenda is implemented.

关键词： Food Energy Water Stakeholder Policy Environmental sustainability

Numerical modeling of the critical pipeline inclination for the elimination of the water accumulation on the pipe floor in oil-water fluid flow

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Petroleum 2021年第2期7卷 209-221页

作者： Xiaoqin Song Dongxin li Xiao Sun Xingjie Mou y.frank Cheng yuexin yang State Key laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China Petrochina Southwest Pipeline Company Chengdu610500China Downhole Operation Company Sinopec Xinan Oilfield Service CorporationDeyang618000China Dept.of Mechanical Engineering University of CalgaryCalgaryABT2N 1N4Canada Civil Aviation Flight University of China Guanghan618307China

In this work,numerical models were developed to investigate the critical inclination of a pipeline to eliminate the water accumulation at the floor of the pipe carrying oil-water *** fluid dynamics software was used to establish a geometric model of the pipe with various inclination angles,and a grid-independent verification was conducted to determine a reasonable meshing *** relationships were determined between the pipe inclination angle and the affecting factors including the flow velocity,viscosity and the pipe diameter,where the water accumulation would not be able to ***,the critical inclination angle increases with the fluid flow *** refluxing of water is the key mechanism causing the water accumulation at the bottom of the *** addition to the fluid flow velocity,an increase in fluid viscosity and a decrease in the pipe diameter cause an increase of the critical inclination angle that the water phase can be carried away by *** model can be used to determine the critical inclination of pipelines carrying oil-water fluid to cause the water accumulation and the operating conditions that can eliminate the accumulation of water phase at the pipe floor.

关键词： Pipeline inclination Oil-water fluid flow Water accumulation Numerical modeling