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Faculty of Informatics - Papers (Archive)

Control

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New Constructions Of Osbe Schemes And Their Applications In Oblivious Access Control, Jinguang Han, Willy Susilo, Yi Mu, Jun Yan Jan 2012

New Constructions Of Osbe Schemes And Their Applications In Oblivious Access Control, Jinguang Han, Willy Susilo, Yi Mu, Jun Yan

Faculty of Informatics - Papers (Archive)

Oblivious signature-based envelope (OSBE) schemes have demonstrated their potential applications in the protection of users privacy and rights. In an OSBE protocol, an encrypted message can only be decrypted by the receiver who holds a valid signature on a public message, while the sender (encrypter) does not know whether the receiver has the signature or not. Our major contributions in this work lie in the following aspects. We improve the notion of OSBE so that a valid credential holder cannot share his/her credential with other users (i. e., all-or-nothing non-transferability). We clarify the relationship between one-round OSBE and identity-based encryption …


Efficient Oblivious Transfers With Access Control, Jinguang Han, Willy Susilo, Yi Mu, Jun Yan Jan 2012

Efficient Oblivious Transfers With Access Control, Jinguang Han, Willy Susilo, Yi Mu, Jun Yan

Faculty of Informatics - Papers (Archive)

Oblivious transfer (OT) is a protocol where a receiver can obtain t-out-of-n services from the sender without releasing anything about his choices. OT can be used to protect user’s privacy. In principle, any user can interact with a server to request some services. This might allow some undesirable users to obtain services from the server. How to ensure that only the authorized receivers can obtain services obliviously is a daunting task. In this paper, we introduce oblivious signature based-on envelope (OSBE) to OT and propose two novel OT schemes, which only allow the legitimate receivers to obtain services obliviously. The …


Application Of Microsimulation To Disease Transmission And Control, A Green, Y Zhang, I Piper, Daniel Keep Jan 2011

Application Of Microsimulation To Disease Transmission And Control, A Green, Y Zhang, I Piper, Daniel Keep

Faculty of Informatics - Papers (Archive)

In this paper, we present an extension of our novel microsimulation technique, as applied to biological infection spread, to estimate the underlying causal parameters driving an infectious process. The underlying simulation framework, Simulacron, was developed in order to understand the development and course of, response to and recovery from single and multiple threats on community populations. Such threats include a range of natural (such as disease spread in communities, fire, flood etc.) and manmade events (such as terrorism, including the use of biological agents, money laundering, smuggling as well as accidents etc.). These threats can cause serious disruption to modern …


Vibration Control Of Seat Considering Vehicle Suspension And Human-Body Models, Haiping Du, Weihua Li, Nong Zhang Jan 2011

Vibration Control Of Seat Considering Vehicle Suspension And Human-Body Models, Haiping Du, Weihua Li, Nong Zhang

Faculty of Informatics - Papers (Archive)

Vehicle seat suspension is one of very important components to provide ride comfort, in particular, commercial vehicles, to reduce driver fatigue due to long hours driving. This paper presents a study on active control of seat suspension to reduce vertical vibration transmitted from uneven road profile to driver body. The control problem will be firstly studied by proposing an integrated seat suspension model which includes vehicle chassis suspension, seat suspension, and driver body model. This is a new concept in the field of study because most of the current active and semi-active seat suspension studies only consider seat suspension or …


T-S Fuzzy H Tracking Control Of Input Delayed Robotic Manipulators, Haiping Du, Weihua Li Jan 2011

T-S Fuzzy H Tracking Control Of Input Delayed Robotic Manipulators, Haiping Du, Weihua Li

Faculty of Informatics - Papers (Archive)

Time delays are often encountered by practical control systems while they are acquiring, processing, communicating, and sending signals. Time delays may affect the system stability and degrade the control system performance if they are not properly dealt with. Taking the classical robot control problem as an example, the significant effect of time delay on the closed-loop system stability has been highlighted in the bilateral teleoperation, where the communication delay transmitted through a network medium has been received widespread attention and different approaches have been proposed to address this problem (Hokayem and Spong, 2006). In addition, examples like processing delays in …


Fuzzy Stability Control Of Robotic Manipulator With Input Delays, Haiping Du, Fazel Naghdy, David A. Stirling Jan 2010

Fuzzy Stability Control Of Robotic Manipulator With Input Delays, Haiping Du, Fazel Naghdy, David A. Stirling

Faculty of Informatics - Papers (Archive)

This paper studies the stabilisation control problem of a robotic manipulator with input delays. To deal with the highly nonlinear dynamics of a robotic manipulator, the model-based Takagi-Sugeno (T-S) fuzzy control strategy is applied. With representing the nonlinear robotic manipulator model as a T-S fuzzy model, sufficient conditions for designing a controller such that the system is stabilised with given decay rate are derived by constructing a less conservative Lyapunov-Krasovskii functional and using a tighter bounding technology for cross terms and the free weighting matrix approach. With appropriate derivation, all the required conditions are expressed as linear matrix inequalities (LMIs). …


Fuzzy Control For Nonlinear Uncertain Electrohydraulic Active Suspensions With Input Constraint, Haiping Du, Nong Zhang Jan 2009

Fuzzy Control For Nonlinear Uncertain Electrohydraulic Active Suspensions With Input Constraint, Haiping Du, Nong Zhang

Faculty of Informatics - Papers (Archive)

This paper presents a Takagi-Sugeno (T-S) model-based fuzzy control design approach for electrohydraulic active vehicle suspensions considering nonlinear dynamics of the actuator, sprung mass variation, and constraints on the control input. The T-S fuzzy model is first applied to represent the nonlinear uncertain electrohydraulic suspension. Then, a fuzzy state feedback controller is designed for the obtained T-S fuzzy model with optimized H infin performance for ride comfort by using the parallel-distributed compensation (PDC) scheme. The sufficient conditions for the existence of such a controller are derived in terms of linear matrix inequalities (LMIs). Numerical simulations on a full-car suspension model …


The Rfid Value Proposition, Benjamin D. Renegar, Katina Michael Jun 2008

The Rfid Value Proposition, Benjamin D. Renegar, Katina Michael

Faculty of Informatics - Papers (Archive)

Radio Frequency Identification (RFID) has the potential to revolutionize the retail industry, yet the linking of this automatic identification (auto-ID) technology to consumer goods has resulted in widespread concern over the potential privacy threats, primarily due to the aspect of traceability it could impose on consumers. As a consequence, privacy has come to be perceived as a barrier stopping RFID adoption in retail in its tracks. When investigating other complex information and communication technologies (ICT), it becomes apparent that consumers often sacrifice privacy in order to take advantage of some form of value afforded by the technology. This interplay between …


Privacy, Value And Control Issues In Four Mobile Business Applications, Benjamin D. Renegar, Katina Michael, M G. Michael Apr 2008

Privacy, Value And Control Issues In Four Mobile Business Applications, Benjamin D. Renegar, Katina Michael, M G. Michael

Faculty of Informatics - Papers (Archive)

This paper presents four case studies that explore the adoption and acceptance of mobile technologies and services within the context of the privacy-value-control (PVC) trichotomy. The technologies studied include: the mobile phone, electronic toll payment tags, e-passports, and loyalty card programs. The study shows that despite the potential barriers to adoption in each of the depicted cases, the applications were embraced with great success soon after their introduction. An understanding of why these mobile innovations succeeded in spite of the concerns surrounding them will serve to help practitioners understand other issues currently plaguing emerging technologies like radio-frequency identification (RFID) tags …


Robotic Machining: Material Removal Rate Control With A Flexible Manipulator, Hui Zhang, Zengxi Pan Jan 2008

Robotic Machining: Material Removal Rate Control With A Flexible Manipulator, Hui Zhang, Zengxi Pan

Faculty of Informatics - Papers (Archive)

Practical material removal rate (MRR) control strategies for industrial robot are presented in this paper. Based on a force control platform, both force signal and spindle power information could be used for MRR measurement. Three different control methods, PI control, adaptive control and fuzzy control, are implemented to satisfy various process requirements. Performance and experimental results are presented and compared. With controlled material removal rate (CMRR), the productivity of robotic machining process could be increased dramatically.


Control Of Energy Storage Interface With A Bidirectional Converter For Photovoltaic Systems, K.N Hasan, M.E Haque, Michael Negnevitsky, Kashem Muttaqi Jan 2008

Control Of Energy Storage Interface With A Bidirectional Converter For Photovoltaic Systems, K.N Hasan, M.E Haque, Michael Negnevitsky, Kashem Muttaqi

Faculty of Informatics - Papers (Archive)

Efficient energy storage is one of the greatest concerns for renewable power generation. This paper focuses on the control of a battery management system (BMS) for photovoltaic (PV) applications with a high efficiency bidirectional converter. The proposed BMS control strategy utilizes the dc bus power and battery state of charge (SOC) for the charging and discharging of the battery with a bidirectional converter. The bidirectional converter includes fewer components and switches, has less switching losses with zero voltage switching, and has high gain buck-boost operations. A new control algorithm of charging-discharging control for the battery storage system is proposed. The …


Robotic Machining From Programming To Process Control: A Complete Solution By Force Control, Zengxi Pan, Hui Zhang Jan 2008

Robotic Machining From Programming To Process Control: A Complete Solution By Force Control, Zengxi Pan, Hui Zhang

Faculty of Informatics - Papers (Archive)

This paper aims to present the critical issues and methodologies to improve robotic machining performance with flexile industrial robots. Design/methodology/approach – A complete solution using active force control is introduced to address various issues during the robotic machining process.

Programming complex couture parts without a CAD model is made easy by using force control functions such as lead-through and path-learning. The problem of process control is treated with a novel methodology that consists of stiffness modeling, real-time deformation compensation for quality and controlled material removal rate for process efficiency.

Experimental results showed that higher productivity as well as better surface …


Modelling Of Hydraulic Governor-Turbine For Control Stabilisation, Michael Negnevitsky, Kashem Muttaqi, Yin Chin Choo Jan 2008

Modelling Of Hydraulic Governor-Turbine For Control Stabilisation, Michael Negnevitsky, Kashem Muttaqi, Yin Chin Choo

Faculty of Informatics - Papers (Archive)

Power system performance is affected by dynamic characteristics of hydraulic governor-turbines during and following any disturbance, such as occurrence of a fault, loss of a transmission line or a rapid change of load. Accurate modelling of hydraulic governor-turbines is essential to characterise and diagnose the system response during an emergency. In this article, both detailed and simplified hydraulic systems governed by proportional-integral-derivative and proportional-integral controllers are modelled. This article examines their transient responses to disturbances through simulation in Matlab/Simulink. The article also investigates the dynamic performance of an isolated hydraulic system through evaluating stability margins, eigenvalues, root loci and frequency …


Output Quality Evaluation Of Photovoltaic Systems With Different Current Control Methods Of Switch-Mode Converters, K. N. Hasan, Md Enamul Haque, Michael Negnevitsky, Kashem Muttaqi Jan 2008

Output Quality Evaluation Of Photovoltaic Systems With Different Current Control Methods Of Switch-Mode Converters, K. N. Hasan, Md Enamul Haque, Michael Negnevitsky, Kashem Muttaqi

Faculty of Informatics - Papers (Archive)

This paper presents a comparative assessment of the current control methods (CCM) of switch-mode converters for photovoltaic (PV) applications. In this paper, average current control, current programmed control, hysteresis current control and nonlinear carrier control methods are addressed considering input fluctuations and load variations for PV systems. Dynamic responses of PV systems are investigated and harmonic analysis is performed. Performances of the above current controllers are examined through simulation and the results are presented. The results show that the selection of different current control techniques depends on the working conditions and the area of applications.


Adaptive Self-Organisation Of Wireless Ad-Hoc Control Networks, Fazel Naghdy, Nathan Simiana Jan 2007

Adaptive Self-Organisation Of Wireless Ad-Hoc Control Networks, Fazel Naghdy, Nathan Simiana

Faculty of Informatics - Papers (Archive)

A novel concept called Wireless ad-hoc Control Networks (WACNets), exploring an ad-hoc approach to networked distributed control, has been under study for the last five years in the research group. Such systems represent a new stage in the evolution of distributed control and monitoring. The work carried out in developing an adaptive self-organisation algorithm for WACNet is reported. The algorithm deploys a distance measure technique while satisfying the rules and assumptions developed for WACNet framework. The effectiveness of the algorithm is verified through computer simulation under a number of given scenarios. The results obtained show that the algorithm effectively drives …


Emotional States Control For On-Line Game Avatars, Ce Zhan, Wanqing Li, Farzad Safaei, Philip Ogunbona Jan 2007

Emotional States Control For On-Line Game Avatars, Ce Zhan, Wanqing Li, Farzad Safaei, Philip Ogunbona

Faculty of Informatics - Papers (Archive)

Although detailed animation has already been achieved in a number of Multi-player On-line Games (MOGs), players have to use text commands to control emotional states of avatars. Some systems have been proposed to implement a real-time automatic system facial expression recognition of players. Such systems can then be used to control avatars emotional states by driving the MOG's "animation engine" instead of text commands. Some of the challenges of such systems is the ability to detect and recognize facial components from low spatial resolution face images. In this paper a system based on an improved face detection method of Viola …


The Importance Of Scenarios In Evaluating The Socio-Ethical Implications Of Location-Based Services, L. Perusco, Katina Michael Dec 2006

The Importance Of Scenarios In Evaluating The Socio-Ethical Implications Of Location-Based Services, L. Perusco, Katina Michael

Faculty of Informatics - Papers (Archive)

Location-based services (LBS) are those applications that utilize the position of an end-user, animal or thing based on a given device (handheld, wearable, interwoven into fabric or implanted), executed for a particular purpose. LBS applications range from those that are mission-critical to those that are used for convenience, from those that are mandatory to those that are voluntary, from those that are targeted at the mass market to those that cater for the needs of a niche market. Location services can be implemented using a variety of access mediums including global positioning systems and radio-frequency identification, rendering approximate or precise …


The Emerging Ethics Of Humancentric Gps Tracking And Monitoring, Katina Michael, Andrew Mcnamee, M G. Michael Jun 2006

The Emerging Ethics Of Humancentric Gps Tracking And Monitoring, Katina Michael, Andrew Mcnamee, M G. Michael

Faculty of Informatics - Papers (Archive)

The Global Positioning System (GPS) is increasingly being adopted by private and public enterprise to track and monitor humans for location-based services (LBS). Some of these applications include personal locators for children, the elderly or those suffering from Alzheimer’s or memory loss, and the monitoring of parolees for law enforcement, security or personal protection purposes. The continual miniaturization of the GPS chipset means that receivers can take the form of wristwatches, mini mobiles and bracelets, with the ability to pinpoint the longitude and latitude of a subject 24/7/365. This paper employs usability context analyses to draw out the emerging ethical …


A Recommended Communicable Disease Surveillance And Control Network To Secure A Healthy And Happy Olympic Game, Ping Yu, Hui Yu Jan 2005

A Recommended Communicable Disease Surveillance And Control Network To Secure A Healthy And Happy Olympic Game, Ping Yu, Hui Yu

Faculty of Informatics - Papers (Archive)

Accurate surveillance and timely control o f the potential outbreak o f infectious diseases is an integral component for organizing big sport events such as Olympics. It relates to the health and safety o f all o f the event participants, the stability o f the society and the credibility o f the event organizing committee and the country in which the event is hold. The current advancement o f information and communication technology (ICT) provides a great opportunity fo r fast aggregation o f huge amount o f relevant data, accurate analysis and assessment to identify potential epidemics, fast …


A Spatial-Temporal Statistical Approach To Command And Control Problems In Battle-Space Digitization, David A. Wendt, Noel A. Cressie, Gardar Johannesson Jan 2001

A Spatial-Temporal Statistical Approach To Command And Control Problems In Battle-Space Digitization, David A. Wendt, Noel A. Cressie, Gardar Johannesson

Faculty of Informatics - Papers (Archive)

There are considerable difficulties in the integration, visualization, and overall management of battle-space information for the purpose of Command and Control (C2). One problem that we see as being important is the timely combination of digital information from multiple (possibly disparate) sources in a dynamically evolving environment. That is, there is a need to assimilate incoming data rapidly, so as to provide the battle commander with up-to-date knowledge about the battle-space and thereby to facilitate the command-decision process. In this paper, we present a spatial-temporal approach to obtaining accurate estimates of the constantly changing battlefield, based on noisy data from …