Access Request Trustworthiness in Weighted Access Control Framework

Weighted factor is given to access eontrol policies to express the importanceof policy and its effect on access control decision. According to this weighted access controlframework, a trustworthiness model for aceess request is also given. In this model, we give themeasure of trustworthiness factor to access request- by using some idea of uncertainty reasoning ofexpert system, present and prove the parallel propagation formula of request trustworthiness factoramong multiple policies, and get thefinal trustworthiness factor to decide whether authorizing. Inthis model, authorization decision is given according to the calculation of request trustworthinessfactor, which is more understandable, more suitable for real requirement and more powerfulforsecurity enhancement than traditional methods. Meanwhile the finer access control granularity isanother advantage.

Unified control and detection framework and its applications: a review, some new results, and future perspectives

Initiated three decades ago,integrated design of controllers and fault detectors has continuously attracted research attention.The recent development of the unified control and detection framework with an observer-based residual generator in its core gives a more general form of the previous works.Its applications to residual centred modelling of uncertain control systems,fault detection in feedback control systems with uncertainties,fault-tolerant control(FTC)as well as control performance degradation monitoring,detection and recovery are introduced.In conclusion,some future perspectives are proposed.

Research and Design on Framework of Quality Risk Control System for Livestock Products

In view of the currant status of the quality risk control of livestock products, the differences between the quality, safety and risk of the livestock products were pointed clearly; the derivative mechanism model of the quality risk was studied; the risk system of livestock products was established; and the types of controllable risk were identified. On this basis, the design principles of risk control framework were established. Then the modular system of risk control was constructed and the attributes of production system were detailed into the describable indicators of risk control based on the thrae-dimensional risks.

A novel control framework for internet based tele-robotics

Aiming at the tele-operation instability caused by time delay of interuet information transfer for internet based tele-robotics, this paper proposes a novel control framework for internet based tele-roboties, which can guarantee the non-distortion-transfer of control information and reduce the difference of action time between the local simulated virtual robot and the remote real robot. This framework is insensitive to the inherent interact time delay, and differs from other tele-robotics systems that try to use some mathematic models to describe the internet delay or take some assumptions. In order to verify the framework, a 4-DOF fischertechnik industry robot tele-operation system has been developed using the new proposed framework. Experimental results demonstrate the applicable performance of the new framework. The framework is open structured and can be applied to other general purposed tele-operation systems.

A Multi-Factor Authentication-Based Framework for Identity Management in Cloud Applications

User’s data is considered as a vital asset of several organizations.Migrating data to the cloud computing is not an easy decision for any organization due to the privacy and security concerns.Service providers must ensure that both data and applications that will be stored on the cloud should be protected in a secure environment.The data stored on the public cloud will be vulnerable to outside and inside attacks.This paper provides interactive multi-layer authentication frameworks for securing user identities on the cloud.Different access control policies are applied for verifying users on the cloud.A security mechanism is applied to the cloud application that includes user registration,granting user privileges,and generating user authentication factor.An intrusion detection system is embedded to the security mechanism to detect malicious users.The multi factor authentication,intrusion detection,and access control techniques can be used for ensuring the identity of the user.Finally,encryption techniques are used for protecting the data from being disclosed.Experimental results are carried out to verify the accuracy and efficiency of the proposed frameworks and mechanism.The results recorded high detection rate with low false positive alarms.

Type Design and Behavior Control for Six Legged Robots

The research on legged robots attracted much attention both from the academia and industry. Legged robots are multi-input multi-output with multiple end-e ector systems. Therefore,the mechanical design and control framework are challenging issues. This paper reviews the development of type synthesis and behavior control on legged robots; introduces the hexapod robots developed in our research group based on the proposed type synthesis method. The control framework for legged robots includes data driven layer,robot behavior layer and robot execution layer. Each layer consists several components which are explained in details. Finally,various experiments were conducted on several hexapod robots. The summarization of the type synthesis and behavior control design constructed in this paper would provide a unified platform for communications and references for future advancement for legged robots.

An Improved Robust Model Predictive Control Approach to Systems with Linear Fractional Transformation Perturbations

In this paper, a robust model predictive control approach is proposed for a class of uncertain systems with time-varying, linear fractional transformation perturbations. By adopting a sequence of feedback control laws instead of a single one, the control performance can be improved and the region of attraction can be enlarged compared with the existing model predictive control （MPC） approaches. Moreover, a synthesis approach of MPC is developed to achieve high performance with lower on-line computational burden. The effectiveness of the proposed approach is verified by simulation examples.

Sand production:A smart control framework for risk mitigation

Due to the current global oil price,the sand production is considered undesirable product and the control of sand production is considered as one of the main concerns of production engineers.It can damage downhole,subsea equipments and surface production facilities,also increasing the risk of catastrophic failure.As a result of that it costs the producers multiple millions of dollars each year.Therefore,there are many different approaches of sand control designed for different reservoir conditions.Selecting an appropriate technique for preventing formation sand production depends on different reservoir parameters.Therefore,choosing the best sand control method is the result of systematic study.In this paper the sand production factors and their effects are presented where the emphasis is given towards the sand prediction to determine the probability of producing sand from the reservoir,followed by the correct prevention implementation of sand control method.The combination of these two is presented as a smart control framework that can be applied for sand production management.

Assemblies of covalent organic framework microcrystals:multiple-dimensional manipulation for enhanced applications

Covalent organic frameworks (COFs) are well known as the next generation of shape-persistent zeolite analogues, which have brought new impetus to the development of porous organic materials as well as two-dimensional polymers. Since the advent of COFs in 2005, many striking findings have definitely proven their great potentials expanding applications across energy,environment and healthcare fields. With thorough exploration over a decade, research interest has been drawn on the scientific challenges on chemistry, while making full play of COF values has remained far from satisfactory yet. Thus opening an avenue to modulating COF assemblies on the multi-scale is no longer just an option, but a necessity for matching the application requirements with enhanced performances. In this mini-review, we summarize the recent progress on design of nanoscale COFs with varying forms. Detailed description is concentrated on the synthetic strategies of COF assemblies such as spheres, fibers,tubes, coatings and films, thereby shedding light on the flexible manipulation over dimensions, compositions and morphologies.Meanwhile, the advanced applications of nanoscale COFs have been discussed here with comparison of their bulky counterparts.

In situ-prepared homogeneous supramolecular organic framework drug delivery systems(sof-DDSs)：Overcoming cancer multidrug resistance and controlled release

Water-soluble three-dimensional porous supramolecular organic frameworks（SOFs） have been demonstrated as a new generation of homogeneous polycationic platforms for anti-cancer drug delivery.The new SOF drug delivery systems（sof-DDSs） can adsorb dianionic pemetrexed（PMX）,a clinically used chemotherapeutic agent instantaneously upon dissolving in water,which is driven by both electrostatic attraction and hydrophobicity.The in situ-prepared PMX@SOFs are highly stable and can avoid important release of the drug during plasm circulation and overcome the multidrug resistance of human breast MCF-7/Adr cancer cells to enter the cancer cells.Acidic microenvironment of cancer cells promotes the release of the drug in cancer cells.Both in vitro and in vivo studies have revealed that sofDDSs considerably improve the treatment efficacy of PMX,leading to 6-12-fold reduction of the IC50 values,as compared with that of PMX alone.The new drug delivery strategy omits the loading process required by most of reported nanoparticle-based delivery systems and thus holds promise for future development of low-cost drug delivery systems

Robust current control of single-phase PWM rectifier based on generalized internal model control

Faults in traction system rectifiers can cause deterioration in system performance,robustness,and continuity.A single fault may propagate and cause the whole system to be shut down.Therefore,improving the robust stability and reliability of the control system is becoming more important.This study presents a robust current control based on a generalized internal model control(GIMC)for single-phase pulse width modulation(PWM)rectifier.The study aims to simultaneously achieve decent dynamic performance and robustness for the rectifiers under current sensor gain faults using generalized internal model control.H∞loop shaping can maintain robustness and achieve acceptable performance for the system in such cases.However,this controller will be conservative during an increase of sensor gain faults.That is,we sacrifice performance for robustness.Therefore,the GIMC structure is proposed to balance robustness and dynamic performance in such cases.The proposed control scheme during sensor gain faults is investigated.Furthermore,the robustness is analyzed using the v-gap metric.The proposed GIMC control framework consists of two parts,nominal and robustness controllers.The system is controlled solely by the nominal controller in normal operation in the absence of current sensor gain faults.If they occur,then the robustness controller will be active to maintain system robustness and achieve acceptable performance.The nominal controller is chosen as H∞loop shaping to assure nominal performance,while the robustness controller is chosen as the plant inverse cascaded by low pass filter to compensate for the sensor gain faults.Hardware-in-loop experimental results indicate that the suggested fault-tolerant control achieves good performance and robustness in comparison to the H∞loop shaping controller.

Eagle Vision-Based Coordinate Landing Control Framework of Unmanned Aerial Vehicles on an Unmanned Surface Vehicle

The coordinate landing control of the unmanned aerial vehicles(UAVs)is a key technology to expand the cooperation between the UAVs and the unmanned surface vehicle(USV).This paper provides an eagle vision-based coordinate landing control framework for the UAV swarm landing on a USV.Back-stepping controller is designed to guarantee that the tracking errors in both of the approaching stage and the landing stage converge to zero.Eagle vision is applied in the visual navigation to improve the landing accuracy.The experiment verified the feasibility of the proposed method.

Dual-quaternion-based satellite pose estimation and control with event-triggered data transmission

This paper proposes an event-triggered active disturbance rejection control framework to achieve the simultaneous position and attitude control of a satellite in proximity operations.Firstly,to facilitate the satellite motion description,we derive the relative kinematics and dynamics in terms of dual quaternions with the considerations of internal uncertainties and external disturbances.Then,two kinds of event-triggered mechanisms in the sensor/observer and controller/actuator channels are proposed to reduce the utilization of onboard communication resources and to improve control performance,respectively.The observation error and tracking error of both the attitude and orbit systems are theoretically proven to be asymptotically bounded.Finally,the simulation results show that the proposed method can achieve simultaneous position and attitude tracking between target and chaser satellites with satisfactory control performance and reduced communication rates.

Longitudinal and lateral control methods from single vehicle to autonomous platoon

To successfully implement the platoon control of connected and automated vehicles,it is necessary to address motion control issues to achieve longitudinal and lateral collaborative control.However,due to traffic capacity limitations and the complex traffic environment in which autonomous and human-driven vehicles coexist,autonomous platoon faces significant risks and challenges.This paper investigates longitudinal and lateral control issues from the perspective of a single vehicle up to a platoon,simulating the performance and suitability of various controllers.First,a longitudinal controller based on fuzzy logic and PID control is employed for speed tracking control of a single vehicle,followed by the adoption of an MPC controller based on the vehicle kinematics model to realize the lateral motion of a single vehicle.Second,the communication methods of the autonomous platoon are discussed,and the longitudinal controller that considers the platoon's various communication topologies is developed.Thirdly,a framework for robust integrated motion control is established,which combines the robust H-infinity longitudinal controller and the APF-based MPC lateral controller.Simulation results validate the effectiveness of the aforementioned controllers and reveal their limitations.

A note on diagnosis and performance degradation detection in automatic control systems towards functional safety and cyber security

This note addresses diagnosis and performance degradation detection issues from an integrated viewpoint of functionality maintenance and cyber security of automatic control systems.It calls for more research attention on three aspects:(i)application of control and detection uni ed framework to enhancing the diagnosis capability of feedback control systems,(ii)projection-based fault detection,and complementary and explainable applications of projection-and machine learning-based techniques,and(iii)system performance degradation detection that is of elemental importance for today's automatic control systems.Some ideas and conceptual schemes are presented and illustrated by means of examples,serving as convincing arguments for research e orts in these aspects.They would contribute to the future development of capable diagnosis systems for functionality safe and cyber secure automatic control systems.