Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

University of Wollongong

Faculty of Informatics - Papers (Archive)

Series

For

Articles 31 - 60 of 67

Full-Text Articles in Physical Sciences and Mathematics

The Wii Remote As An Input Device For 3d Interaction In Immersive Head-Mounted Display Virtual Reality, Yang-Wai Chow Jan 2008

The Wii Remote As An Input Device For 3d Interaction In Immersive Head-Mounted Display Virtual Reality, Yang-Wai Chow

Faculty of Informatics - Papers (Archive)

There has been a lot of interest regarding the possibilities that the motion sensing technology in the Wii Remote can offer. This study investigates the feasibility of using the Wii Remote for 3D interaction in immersive Head-Mounted Display (HMD) virtual reality. Normal usage of the Wii Remote requires that the controller to be pointed in a certain direction, typically towards the display. The requirements of an input device for interaction in immersive HMD virtual reality differ from that of normal display systems, in that the user should ideally be able to turn around in the virtual environment. A number of …


Optimisation Of Distributed Generation Units And Shunt Capacitors For Economic Operation Of Distribution Systems, Kai Zou, Sarath Perera, Kashem Muttaqi, Ashish P. Agalgaonkar Jan 2008

Optimisation Of Distributed Generation Units And Shunt Capacitors For Economic Operation Of Distribution Systems, Kai Zou, Sarath Perera, Kashem Muttaqi, Ashish P. Agalgaonkar

Faculty of Informatics - Papers (Archive)

The integration of Distributed Generation (DG) units and shunt capacitors can be considered as an alternative approach for distribution system expansion planning not only to improve power supply quality and reliability, but also to defer major system updates. In this paper, the techno-economic issues of distribution system expansion planning with optimal sizing and siting of DG units and shunt capacitors are addressed. The minimisation of overall investment cost with the integration of DG units and shunt capacitors is assessed with the consideration of supply quality, reliability and energy loss. A new planning methodology by using Particle Swarm Optimisation (PSO) is …


A Pragmatic Gis-Oriented Ontology For Location Based Services, Jun Shen, Aneesh Krishna, Shuai Yuan, Ke Cai, Yuemin Qin Jan 2008

A Pragmatic Gis-Oriented Ontology For Location Based Services, Jun Shen, Aneesh Krishna, Shuai Yuan, Ke Cai, Yuemin Qin

Faculty of Informatics - Papers (Archive)

With advances in automatic position sensing and wireless connectivity, location-based services (LBS) are rapidly developing, particularly in fields of geographic, tourism and logistic information systems. Currently, Web service has been viewed as one of most significant innovations in business industry, and designed on demand to provide spatial related information for LBS consumption. However, the traditional Web Service Description Language (WSDL) cannot meet those requirements, as WSDL is not able to support semantic content and information. In recent years, Ontology came up with an effective approach to enhance service description, automated discovery, dynamic composition, enactment, and other tasks such as managing …


A Scalable Lightweight Distributed Crawler For Crawling With Limited Resources, Milly W. Kc, Markus Hagenbuchner, Ah Chung Tsoi Jan 2008

A Scalable Lightweight Distributed Crawler For Crawling With Limited Resources, Milly W. Kc, Markus Hagenbuchner, Ah Chung Tsoi

Faculty of Informatics - Papers (Archive)

Web page crawlers are an essential component in a number of Web applications. The sheer size of the Internet can pose problems in the design of Web crawlers. All currently known crawlers implement approximations or have limitations so as to maximize the throughput of the crawl, and hence, maximize the number of pages that can be retrieved within a given time frame. This paper proposes a distributed crawling concept which is designed to avoid approximations, to limit the network overhead, and to run on relatively inexpensive hardware. A set of experiments, and comparisons highlight the effectiveness of the proposed approach.


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 …


A Diagrammatic Reasoning System For The Description Logic Alc, Peter W. Eklund, Frithjof Dau Jan 2008

A Diagrammatic Reasoning System For The Description Logic Alc, Peter W. Eklund, Frithjof Dau

Faculty of Informatics - Papers (Archive)

Diagrammatic reasoning is a tradition of visual logic that allows sentences that are equivalent to first order logic to be written in a visual or structural form: usually for improved usability. A calculus for the diagram can then be defined that allows well-formed formulas to be derived. This calculus is intended in the analog of logical inference. Description logics (DLs) have become a popular knowledge representation and processing language. DLs correspond to decidable fragments of first order logic; their notation is in the style of symbolic, variable-free formulas. Moreover, DLs are equipped with table au theorem provers that are proven …


Conditions For The Assessment Of The Harmonic Compliance Of An Installation, Timothy J. Browne, Sarath Perera, Victor J. Gosbell Jan 2008

Conditions For The Assessment Of The Harmonic Compliance Of An Installation, Timothy J. Browne, Sarath Perera, Victor J. Gosbell

Faculty of Informatics - Papers (Archive)

Methods of allocating harmonic emission limits to customer installations have evolved considerably, as evidenced by the development of harmonic guides such as IEEE-519 and IEC/TR 61000-3-6. However, there is only limited consensus on appropriate techniques validating compliance of installations with those limits. Existing techniques are reviewed and related problems are examined. Conditions which acceptable tests of compliance should meet are proposed.


Elimination Of Gamma Nonlinear Luminance Effects For Digital Video Projection Phase Measuring Profilometers, Matthew J. Baker, Jiangtao Xi, Joe F. Chicharo Jan 2008

Elimination Of Gamma Nonlinear Luminance Effects For Digital Video Projection Phase Measuring Profilometers, Matthew J. Baker, Jiangtao Xi, Joe F. Chicharo

Faculty of Informatics - Papers (Archive)

In this paper we are concerned with the elimination of gamma related errors by employing a simple and direct approach, specifically, for phase measuring profilometry (PMP) methods. The harmonic structure of a gamma distorted fringe is investigated and the implications of j for the PMP algorithm is studied. The minimum requirements in terms of number of Steps for appropriate elimination of j related phase residuals is identified and verified via both simulation and practical experimentation.


An Energy-Aware Multilevel Clustering Algorithm For Wireless Sensor Networks, Xinfang Yan, Jiangtao Xi, Joe F. Chicharo, Yanguang Yu Jan 2008

An Energy-Aware Multilevel Clustering Algorithm For Wireless Sensor Networks, Xinfang Yan, Jiangtao Xi, Joe F. Chicharo, Yanguang Yu

Faculty of Informatics - Papers (Archive)

Clustering sensors nodes as the basic of routing is an efficient mechanism for prolonging the lifetime of wireless sensor networks. In this paper, the high-efficient multilevel clustering is abstracted as a root tree which has the performances of the minimal relay set and the maximal weight according to graph theory. A mathematical model for the clustering virtual backbone is built. Based on the model, an algorithm called energy-aware multilevel clustering (EAMC) is proposed. The EAMC can reduce the number of relays used for data transmission by minimizing the amount of the nodes in the root tree (that is cluster-head). Furthermore, …


Ontology-Based Knowledge Representation For A P2p Multi-Agent Distributed Intrusion Detection System, Dayong Ye, Quan Bai, Minjie Zhang Jan 2008

Ontology-Based Knowledge Representation For A P2p Multi-Agent Distributed Intrusion Detection System, Dayong Ye, Quan Bai, Minjie Zhang

Faculty of Informatics - Papers (Archive)

Many research efforts on application of ontology in network security have been done in the past decade. However, they mostly stop at initial proposal or focus on framework design without detailed representation of intrusion or attack and relevant detection knowledge with ontology. In this paper, the design and implementation of ontology-based knowledge representation for a peer-to-peer multi-agent distributed intrusion detection system (ontology-based MADIDS) are introduced. An example which demonstrates the representation of an attack with ontology and the relevant detection process is also presented. In ontology-Based MADIDS, ontology technique enables peers in the system and agents in one peer to …


Voltage Unbalance Emission Limits For Installations: General Guidelines And System Specific Considerations, Robert Koch, Alexander Baitch, Sarath Perera, Prabodha Paranavithana Jan 2008

Voltage Unbalance Emission Limits For Installations: General Guidelines And System Specific Considerations, Robert Koch, Alexander Baitch, Sarath Perera, Prabodha Paranavithana

Faculty of Informatics - Papers (Archive)

Guidelines for developing voltage unbalance emission limits for installations connected to EHV, HV, and MV power systems have recently been published as a technical report by the International Electrotechnical Commission (IEC). These guidelines, based on the work of Joint Working Group CIGRE/CIRED C4.103, are intended to provide a common basis for the development of similar guidelines or standards in specific countries. This paper reviews these international guidelines and the background to the development of specific recommendations made in the technical report. It also considers elements of these guidelines that may relate to specific network considerations, and therefore may be of …


Continuum Modelling For Carbon And Boron Nitride Nanostructures, James M. Hill, Ngamta Thamwattana Jan 2007

Continuum Modelling For Carbon And Boron Nitride Nanostructures, James M. Hill, Ngamta Thamwattana

Faculty of Informatics - Papers (Archive)

Continmuum based models are presented here for certain boron nitride and carbon nanostructures.


A Wireless Sensor Node Architecture Using Remote Power Charging, For Interaction Applications, Matthew D'Souza, Konstanty Bialkowski, Adam Postula, Montserrat B. Ros Jan 2007

A Wireless Sensor Node Architecture Using Remote Power Charging, For Interaction Applications, Matthew D'Souza, Konstanty Bialkowski, Adam Postula, Montserrat B. Ros

Faculty of Informatics - Papers (Archive)

The wireless sensor node architecture proposed inthis paper is optimized for use in a wireless interactivepoint, listen and see system. In particular, we focus ondeveloping a wireless sensor node that can beremotely charged by harvesting microwave energy.The current system implementation allows a user toaccess information from a remote sensor via theirmobile computing device. These sensors are limited incomplexity due to the limited power available, and arecumbersome since manual intervention is required toreplace its batteries. We propose a system wherebattery powered wireless sensor nodes can berecharged by harvesting energy from a microwaveRadio Frequency (RF) signal source. The remotepower charging module of …


System Architecture And Mobility Management For Mobile Immersive Communications, Mehran Dowlatshahi, Farzad Safaei Jan 2007

System Architecture And Mobility Management For Mobile Immersive Communications, Mehran Dowlatshahi, Farzad Safaei

Faculty of Informatics - Papers (Archive)

We propose a system design for delivery of immersive communications to mobile wireless devices based on a distributed proxy model. It is demonstrated that this architecture addresses key technical challenges for the delivery of these services, that is, constraints on link capacity and power consumption in mobile devices. However, additional complexity is introduced with respect to application layer mobility management. The paper proposes three possible methods for updating proxy assignments in response to mobility management and compares the performance of these methods.


Scalability Of Manet Routing Protocols For Heterogeneous And Homogenous Networks, Huda Mubarak Al Amri, Mehran Abolhasan, Tadeusz A. Wysocki Jan 2007

Scalability Of Manet Routing Protocols For Heterogeneous And Homogenous Networks, Huda Mubarak Al Amri, Mehran Abolhasan, Tadeusz A. Wysocki

Faculty of Informatics - Papers (Archive)

In Mobile Ad hoc Network (MANET), mobility, traffic and node density are main network conditions that significantly affect the performance of routing protocols. Much of the previous researches in MANET routing have focused on developing strategies, which suit one specific networking scenario. Therefore, there is no existing protocol that can work well in all different networking scenarios. This paper reviews characteristics of each different classes of routing protocols. Moreover, most of current routing protocols assume homogeneous networking conditions where all nodes have the same capabilities and resources. Although homogenous networks are easy to model and analysis, they exhibits poor scalability …


A Numerical Model For Multiphase Flow Based On The Gmpps Formulation, Part I Kinematics, Song-Ping Zhu, Frank Bierbrauer Jan 2007

A Numerical Model For Multiphase Flow Based On The Gmpps Formulation, Part I Kinematics, Song-Ping Zhu, Frank Bierbrauer

Faculty of Informatics - Papers (Archive)

The CFD modeling of two dimensional multiphase ows is a useful tool in industry, although accurate modeling itself remains a difficult task. One of the difficulties is to track the complicated topological deformations of the interfaces between di erent phases. This paper describes a marker-particle method designed to track fluid interfaces for fluid ows of at least three phases. The interface-tracking scheme presented in this paper is the first part of a series of papers presenting our complete model based on a one-field Godunov marker-particle projection scheme (GMPPS). In this part, we shall focus on the presentation of the interface-tracking …


Force Distribution For Double-Walled Carbon Nanotubes, Duangkamon Baowan, James M. Hill Jan 2006

Force Distribution For Double-Walled Carbon Nanotubes, Duangkamon Baowan, James M. Hill

Faculty of Informatics - Papers (Archive)

Advances in technology have led to the creation of many nano-scale devices and carbon nanotubes are representative materials to construct these devices. Double-walled carbon nanotubes with the inner tube oscillating can be used as gigahertz oscillators and form the basis of possible nano-electronic devices. Such gigahertz oscillating devices made from carbon nanotubes might be instrumental in the micro-computer industry, which is predominantly based on electron transport phenomena. There are many experiments and molecular dynamics simulations which show that a wave is generated on the outer cylinder by the oscillation of the carbon nanotubes and that the frequency of this wave …


Arbitrary Ratio Sample Rate Conversion Using B-Spline Interpolation For Software Defined Radio, Xiaojing Huang Jan 2006

Arbitrary Ratio Sample Rate Conversion Using B-Spline Interpolation For Software Defined Radio, Xiaojing Huang

Faculty of Informatics - Papers (Archive)

Arbitrary ratio sampling rate conversion (SRC) structure using B-spline interpolation is proposed for software defined radio (SDR) in this paper. By combining SRC with SDR’s transmitter/receiver filter, the constraint on SRC reconstruction filter can be relaxed, and an overall computational reduction can be achieved. The mixed-width B-spline is introduced so that both antiimaging and anti-aliasing requirements for SRC are satisfied. The passband droop introduced by the B-spline interpolation is compensated by a linear phase digital filter incorporated in the SRC structure so that the overall frequency response approaches the desired frequency response of the SDR’s transmitter/receiver filter. To make the …


Facial Expression Recognition For Multiplayer Online Games, Ce Zhan, Wanqing Li, Philip O. Ogunbona, Farzad Safaei Jan 2006

Facial Expression Recognition For Multiplayer Online Games, Ce Zhan, Wanqing Li, Philip O. Ogunbona, Farzad Safaei

Faculty of Informatics - Papers (Archive)

The Multiplayer Online Game (MOG) becomes more popular than any other types of computer games for its collaboration, communication and interaction ability. However, compared with the ordinary human communication, the MOG still has many limitations, especially in communication using facial expressions. Although detailed facial animation has already been achieved in a number of MOGs, players have to use text commands to control avatars expressions. In this paper, we briefly review the state of the art in facial expression recognition and propose an automatic expression recognition system that can be integrated into a MOG to control the avatar’s facial expressions. We …


An Ontology-Based Approach For Expert And Knowledge Mining In Complex Multi-Agent Systems, Minjie Zhang, Xijin Tang, Quan Bai, Jifa Gu Jan 2006

An Ontology-Based Approach For Expert And Knowledge Mining In Complex Multi-Agent Systems, Minjie Zhang, Xijin Tang, Quan Bai, Jifa Gu

Faculty of Informatics - Papers (Archive)

Complex problems require diverse expertise and multiple techniques to solve. In order to solve such problems, complex multi-agent systems include numbers of heterogeneous agents, which may include both of human experts and autonomous agents, to work together toward some complex problems. Most complex multi-agent systems are working in open domains. Due to heterogeneities and dynamic working environments, expertise and capabilities of agents might not be well estimated and presented in the system. Therefore, how to discover useful knowledge from human and autonomous experts, make more accurate estimation for experts' capabilities and to find out suitable expert(s) to solve incoming problems …


Generic Scheduling Framework And Algorithm For Time-Varying Wireless Networks, Gengfa Fang, Yi Sun, Jihua Zhou, Jinglin Shi, Eryk Dutkiewicz Jan 2006

Generic Scheduling Framework And Algorithm For Time-Varying Wireless Networks, Gengfa Fang, Yi Sun, Jihua Zhou, Jinglin Shi, Eryk Dutkiewicz

Faculty of Informatics - Papers (Archive)

In this paper, the problem of scheduling multiple users sharing a time varying wireless channel is studied, in networks such as in 3G CDMA and IEEE 802.16. We propose a new generic wireless packet scheduling framework (WPSF), which takes into account not only the quality of service (QoS) requirements but also the wireless resource consumed. The framework is generic in the sense that it can be used with different resource constraints and QoS requirements depending on the traffic flow types. Subsequently, based on this framework a minimum rate and channel aware (MRCA) scheduling algorithm is presented. MRCA attempts to greedily …


Sava: A Novel Self-Adaptive Vertical Handoff Algorithm For Heterogeous Wireless Networks, Min Liu, Zhong-Cheng Li, Xiao-Bing Guo, Eryk Dutkiewicz, Ming-Hui Wang Jan 2006

Sava: A Novel Self-Adaptive Vertical Handoff Algorithm For Heterogeous Wireless Networks, Min Liu, Zhong-Cheng Li, Xiao-Bing Guo, Eryk Dutkiewicz, Ming-Hui Wang

Faculty of Informatics - Papers (Archive)

The next generation wireless networking (4G) is envisioned as a convergence of different wireless access technologies with diverse levels of performance. Vertical handoff (VHO) is the basic requirement for convergence of different access technologies and has received tremendous attention from the academia and industry all over the world. During the VHO procedure, handoff decision is the most important step that affects the normal working of communication. In this paper, we propose a novel vertical handoff decision algorithm, self- adaptive VHO algorithm (SAVA), and compare its performance with conventional algorithms. SAVA synthetically considers the long term movement region and short term …


Mathematical Modelling For A C60 Carbon Nanotube Oscillator, Barry J. Cox, Ngamta Thamwattana, James M. Hill Jan 2006

Mathematical Modelling For A C60 Carbon Nanotube Oscillator, Barry J. Cox, Ngamta Thamwattana, James M. Hill

Faculty of Informatics - Papers (Archive)

The discovery of fullerenes C60 and carbon nanotubes has created an enormous impact on nanotechnology. Because of their unique mechanical and electronic properties, such as low weight, high strength, flexibility and thermal stability, fullerenes C60 and carbon nanotubes are of considerable interest to researchers from many scientific areas. One problem that has attracted much attention is the creation of gigahertz oscillators. While there are difficulties for micromechanical oscillators, or resonators, to reach a frequency in the gigahertz range, it is possible for nanomechanical systems to achieve this. A number of studies have found that the sliding of the …


A System For The 3d Reconstruction Of The Human Face Using The Structured Light Approach, Dean Mcguire, Prashan Premaratne Jan 2006

A System For The 3d Reconstruction Of The Human Face Using The Structured Light Approach, Dean Mcguire, Prashan Premaratne

Faculty of Informatics - Papers (Archive)

This paper will describe a computer vision system under development with the aim of use in robust facial recognition applications. The system employs the structured light approach to solve the correspondence problem. The system has been designed with ease of use in mind with calibration procedures designed to be simple enough to be carried out without the use of precision measuring equipment, but robust enough to provide good quality 3D reconstructions. The hardware in use is of consumer grade and is being used in an unmodified form. Early reconstructions of faces based on the projection of a striped pattern have …


Wfms-Based Data Integration For E-Learning, Jianming Yong, Jun Yan, Xiaodi Huang Jan 2006

Wfms-Based Data Integration For E-Learning, Jianming Yong, Jun Yan, Xiaodi Huang

Faculty of Informatics - Papers (Archive)

As more and more organisations and institutions are moving towards the e-learning strategy, more and more disparate data are distributed by different e-learning systems. How to effectively use this vast amount of distributed data becomes a big challenge. This paper addresses this challenge and works out a new mechanism to implement data integration for e-learning. A workflow management system based (WFMS-based) data integration model is contributed to the e-learning.


Fitness Evaluation For Structural Optimisation Genetic Algorithms Using Neural Networks, Koren Ward, Timothy J. Mccarthy Jan 2006

Fitness Evaluation For Structural Optimisation Genetic Algorithms Using Neural Networks, Koren Ward, Timothy J. Mccarthy

Faculty of Informatics - Papers (Archive)

This paper relates to the optimisation of structural design using Genetic Algorithms (GAs) and presents an improved method for determining the fitness of genetic codes that represent possible design solutions by using a neural network to generalize fitness. Two problems that often impede design optimization using genetic algorithms are expensive fitness evaluation and high epistasis. In this paper we show that by using a neural network as a fitness approximator, optimal solutions to certain design problems can be achieved in significantly less generations and with considerably less fitness evaluations.


Decision Aided Joint Compensation Of Clipping Noise And Nonlinearity For Mimo-Ofdm Systems, Shouyi Yang, Jiangtao Xi, Xiaomin Mu Jan 2005

Decision Aided Joint Compensation Of Clipping Noise And Nonlinearity For Mimo-Ofdm Systems, Shouyi Yang, Jiangtao Xi, Xiaomin Mu

Faculty of Informatics - Papers (Archive)

In this paper, we propose a new iterative approach to compensate the nonlinearity and clipping noise in multi-input multi-output orthogonal frequency division multiplexing (MlMO-OFDM) system with nonlinear channel. The proposed approach consists of two stages. Firstly a decision aided method is proposed to eliminate the nonlinearity introduced by high power transmit amplifier (HPA). Then this improved decision observations are employed to achieve the clipping noise compensation. The effectiveness of the proposed approach has been verified by computer simulations.


An Adaptive Scalable Multiuser-Ofdm System For Multimedia Transmission Over Fading Channels, Ahmed Muthana M. Nadhim, Jianhua He, Jiangtao Xi, Zongkai Yang Jan 2005

An Adaptive Scalable Multiuser-Ofdm System For Multimedia Transmission Over Fading Channels, Ahmed Muthana M. Nadhim, Jianhua He, Jiangtao Xi, Zongkai Yang

Faculty of Informatics - Papers (Archive)

In this paper, an adaptive scalable multiuser-OFDM system was proposed for multimedia transmission over fading channels. The proposed adaptive algorithm can adapt according to the channel status information of each user's channel status. This algorithm dynamically changes according to the user's channel changes; this can keep fixed QoS at the physical layer. Another predefined QoS for different sessions and services to be provided for different users. This QoS can be guaranteed by multimedia scalability. Scalability can adapt to the service requirements, in terms of transmission data rate and bandwidth. As a result, a robust multimedia transmission scheme is achieved by …


Signal Processing Methods Implemented In A Novel Fbg Sensing System For Vibration/Dynamic Strain Measurement, Xingyuan Xu, Enbang Li, Jiangtao Xi, Joe F. Chicharo Jan 2005

Signal Processing Methods Implemented In A Novel Fbg Sensing System For Vibration/Dynamic Strain Measurement, Xingyuan Xu, Enbang Li, Jiangtao Xi, Joe F. Chicharo

Faculty of Informatics - Papers (Archive)

We have demonstrated a novel Fiber Bragg Grating sensing system based on a Fabry-Perot tunable filter for measuring dynamic processes. This system is very suitable for multipoint vibration or dynamic strain detection. However, in some conditions, the response time of Fabry-Perot tunable filter will influence the sensitivity of the sensor that the sensitivity is not kept constant. Therefore, post-processing for the measured vibration signal is necessary to solve this problem. In this paper, the demodulation technique of this system is briefly described and two signal processing methods are introduced to deal with the measured signal to obtain stable measurement of …


Multi-Frequency And Multiple Phase-Shift Sinusoidal Fringe Projection For 3d Profilometry, Enbang Li, X. Peng, Jiangtao Xi, Joe F. Chicharo, Jianquan Yao, D.W. Zhang Jan 2005

Multi-Frequency And Multiple Phase-Shift Sinusoidal Fringe Projection For 3d Profilometry, Enbang Li, X. Peng, Jiangtao Xi, Joe F. Chicharo, Jianquan Yao, D.W. Zhang

Faculty of Informatics - Papers (Archive)

In this paper, we report on a laser fringe projection set-up, which can generate fringe patterns with multiple frequencies and phase shifts. Stationary fringe patterns with sinusoidal intensity distributions are produced by the interference of two laser beams, which are frequency modulated by a pair of acousto-optic modulators (AOMs). The AOMs are driven by two RF signals with the same frequency but a phase delay between them. By changing the RF frequency and the phase delay, the fringe spatial frequency and phase shift can be electronically controlled, which allows high-speed switching from one frequency or phase to another thus makes …