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Full-Text Articles in Physical Sciences and Mathematics

3d Face Recognition Based On A Modified Icp Method, Kankan Zhao, Jiangtao Xi, Yanguang Yu, Joe F. Chicharo Jan 2011

3d Face Recognition Based On A Modified Icp Method, Kankan Zhao, Jiangtao Xi, Yanguang Yu, Joe F. Chicharo

Faculty of Informatics - Papers (Archive)

3D face recognition technique has gained much more attention recently, and it is widely used in security system, identification system, and access control system, etc. The core technique in 3D face recognition is to find out the corresponding points in different 3D face images. The classic partial Iterative Closest Point (ICP) method is iteratively align the two point sets based on repetitively calculate the closest points as the corresponding points in each iteration. After several iterations, the corresponding points can be obtained accurately. However, if two 3D face images with different scale are from the same person, the classic partial …


Age Estimation Based On Extended Non-Negative Matrix Factorization, Ce Zhan, Wanqing Li, Philip Ogunbona Jan 2011

Age Estimation Based On Extended Non-Negative Matrix Factorization, Ce Zhan, Wanqing Li, Philip Ogunbona

Faculty of Informatics - Papers (Archive)

Previous studies suggested that local appearance-based methods are more efficient than geometric-based and holistic methods for age estimation. This is mainly due to the fact that age information are usually encoded by the local features such as wrinkles and skin texture on the forehead or at the eye corners. However, the variations of theses features caused by other factors such as identity, expression, pose and lighting may be larger than that caused by aging. Thus, one of the key challenges of age estimation lies in constructing a feature space that could successfully recovers age information while ignoring other sources of …


Methane Observations From The Greenhouse Gases Observing Satellite: Comparison To Ground-Based Tccon Data And Model Calculations, Robert Parker, Hartmut Boesch, Austin Cogan, Annemarie Fraser, Liang Feng, Paul Palmer, Janina Messerschmidt, Nicholas M. Deutscher, David W. Griffith, Justus Notholt, Paul O. Wennberg, Debra Wunch Jan 2011

Methane Observations From The Greenhouse Gases Observing Satellite: Comparison To Ground-Based Tccon Data And Model Calculations, Robert Parker, Hartmut Boesch, Austin Cogan, Annemarie Fraser, Liang Feng, Paul Palmer, Janina Messerschmidt, Nicholas M. Deutscher, David W. Griffith, Justus Notholt, Paul O. Wennberg, Debra Wunch

Faculty of Science - Papers (Archive)

We report new short-wave infrared (SWIR) column retrievals of atmospheric methane (X CH4) from the Japanese Greenhouse Gases Observing SATellite (GOSAT) and compare observed spatial and temporal variations with correlative ground-based measurements from the Total Carbon Column Observing Network (TCCON) and with the global 3-D GEOS-Chem chemistry transport model. GOSAT X CH4 retrievals are compared with daily TCCON observations at six sites between April 2009 and July 2010 (Bialystok, Park Falls, Lamont, Orleans, Darwin and Wollongong). GOSAT reproduces the site-dependent seasonal cycles as observed by TCCON with correlations typically between 0.5 and 0.7 with an estimated single-sounding precision between 0.4-0.8%. …


Airborne And Ground-Based Measurements Of The Trace Gases And Particles Emitted By Prescribed Fires In The United States, I R. Burling, R J. Yokelson, S K. Akagi, S P. Urbanski, C E. Wold, David W. Griffith, T J. Johnson, J Reardon, D R. Weise Jan 2011

Airborne And Ground-Based Measurements Of The Trace Gases And Particles Emitted By Prescribed Fires In The United States, I R. Burling, R J. Yokelson, S K. Akagi, S P. Urbanski, C E. Wold, David W. Griffith, T J. Johnson, J Reardon, D R. Weise

Faculty of Science - Papers (Archive)

We have measured emission factors for 19 tracegas species and particulate matter (PM2.5) from 14 prescribedfires in chaparral and oak savanna in the southwesternUS, as well as conifer forest understory in the southeasternUS and Sierra Nevada mountains of California. These arelikely the most extensive emission factor field measurementsfor temperate biomass burning to date and the only publishedemission factors for temperate oak savanna fuels. This studyhelps to close the gap in emissions data available for temperatezone fires relative to tropical biomass burning. Wepresent the first field measurements of the biomass burningemissions of glycolaldehyde, a possible precursor for aqueousphase secondary organic aerosol …


An Ambient Multimedia User Experience Feedback Framework Based On User Tagging And Eeg Biosignals, Eva Cheng, Stephen J. Davis, Ian Burnett, Christian H. Ritz Jan 2011

An Ambient Multimedia User Experience Feedback Framework Based On User Tagging And Eeg Biosignals, Eva Cheng, Stephen J. Davis, Ian Burnett, Christian H. Ritz

Faculty of Informatics - Papers (Archive)

Multimedia is increasingly accessed online and within social networks; however, users are typically limited to visual/auditory stimulus through media presented onscreen with accompanying audio over speakers. Whilst recent research studying additional ambient sensory multimedia effects recorded numerical scores of perceptual quality, the users’ time-varying emotional response to the ambient sensory feedback is not considered. This paper thus introduces a framework to evaluate user ambient quality of multimedia experience and discover users’ time-varying emotional responses through explicit user tagging and implicit EEG biosignal analysis. In the proposed framework, users interact with the media via discrete tagging activities whilst their EEG biosignal …


Estimates Of Probable Dementia Prevalence From Population-Based Surveys Compared With Dementia Prevalence Estimates Based On Meta-Analyses, Kaarin J. Anstey, Richard A. Burns, Carole Birrell, David G. Steel, Kim M. Kiely, Mary A. Luszcz Jan 2010

Estimates Of Probable Dementia Prevalence From Population-Based Surveys Compared With Dementia Prevalence Estimates Based On Meta-Analyses, Kaarin J. Anstey, Richard A. Burns, Carole Birrell, David G. Steel, Kim M. Kiely, Mary A. Luszcz

Faculty of Informatics - Papers (Archive)

Background: National data on dementia prevalence are not always available, yet it may be possible to obtain estimates from large surveys that include dementia screening instruments. In Australia, many of the dementia prevalence estimates are based on European data collected between 15 and 50 years ago. We derived populationbased estimates of probable dementia and possible cognitive impairment in Australian studies using the Mini-Mental State Examination (MMSE), and compared these to estimates of dementia prevalence from meta-analyses of European studies.

Methods: Data sources included a pooled dataset of Australian longitudinal studies (DYNOPTA), and two Australian Bureau of Statistics National …


An Approach To Studying Location-Based Services Regulation In Australia, Roba Abbas Jan 2010

An Approach To Studying Location-Based Services Regulation In Australia, Roba Abbas

Faculty of Informatics - Papers (Archive)

Location-based Services (LBS) afford a means of positioning, tracing and tracking individuals and objects, for purposes such as emergency management, employee monitoring, and consumer convenience. This paper reviews the present LBS setting and expected developments in this space, with a particular focus on the implications for Australian research and regulatory efforts. The origins of LBS in the mobile-commerce field are explored, incorporating an appraisal of the underlying positioning technology, the stakeholders in the LBS value chain, and the regulatory environment in which these services are employed. There is an evident disparity between the implementation of LBS technologies and the introduction …


Action Recognition Based On A Bag Of 3d Points, Wanqing Li, Zhenyu Zhang, Zicheng Liu Jan 2010

Action Recognition Based On A Bag Of 3d Points, Wanqing Li, Zhenyu Zhang, Zicheng Liu

Faculty of Informatics - Papers (Archive)

This paper presents a method to recognize human actions from sequences of depth maps. Specifically, we employ an action graph to model explicitly the dynamics of the actions and a bag of 3D points to characterize a set of salient postures that correspond to the nodes in the action graph. In addition, we propose a simple, but effective projection based sampling scheme to sample the bag of 3D points from the depth maps. Experimental results have shown that over 90% recognition accuracy were achieved by sampling only about 1% 3D points from the depth maps. Compared to the 2D silhouette …


Pbtrust: A Priority-Based Trust Model For Service Selection In General Service-Oriented Environments, Xing Su, Minjie Zhang, Yi Mu, Kwang Mong Sim Jan 2010

Pbtrust: A Priority-Based Trust Model For Service Selection In General Service-Oriented Environments, Xing Su, Minjie Zhang, Yi Mu, Kwang Mong Sim

Faculty of Informatics - Papers (Archive)

How to choose the best service provider (agent), which a service consumer can trust in terms of the quality and success rate of the service in an open and dynamic environment, is a challenging problem in many service-oriented applications such as Internet-based grid systems, e-trading systems, as well as service-oriented computing systems. This paper presents a Priority-Based Trust (PBTrust) model for service selection in general service-oriented environments. The PBTrust is robust and novel from several perspectives. (1) The reputation of a service provider is derived from referees who are third parties and had interactions with the provider in a rich …


A Human Gait Classification Method Based On Radar Doppler Spectrograms, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Moeness G. Amin Jan 2010

A Human Gait Classification Method Based On Radar Doppler Spectrograms, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Moeness G. Amin

Faculty of Informatics - Papers (Archive)

An image classification technique, which has recently been introduced for visual pattern recognition, is successfully applied for human gait classification based on radar Doppler signatures depicted in the time-frequency domain. The proposed method has three processing stages. The first two stages are designed to extract Doppler features that can effectively characterize humanmotion based on the nature of arm swings, and the third stage performs classification. Three types of arm motion are considered: free-arm swings, one-arm confined swings, and no-arm swings. The last two arm motions can be indicative of a human carrying objects or a person in stressed situations. The …


Data Security And Information Privacy For Pda Accessible Clinical-Log For Medical Education In Problem-Based Learning (Pbl) Approach, Rattiporn Luanrattana, Khin Than Win, John A. Fulcher Jan 2010

Data Security And Information Privacy For Pda Accessible Clinical-Log For Medical Education In Problem-Based Learning (Pbl) Approach, Rattiporn Luanrattana, Khin Than Win, John A. Fulcher

Faculty of Informatics - Papers (Archive)

Data security and information privacy are the important aspects to consider for the use of mobile technology for recording clinical experience and encounter in medical education. Objective: This study aims to address the qualitative findings of the appropriate data security and information privacy for PDA accessible clinical-log in problem-based learning (PBL) approach in medical education. Method: The semi-structured interviews were conducted with the medical faculty members, honorary clinical academics and medical education technology specialists. Results: Data security and information access plan were determined for managing clinical-log data. The results directed the guideline for the future development and implementation of clinical-log …


Support-Based Distributed Optimisation: An Approach To Radiotherapy Patient Scheduling, Graham Billiau, Chee-Fon Chang, Andrew Alexis Miller, Aditya K. Ghose Jan 2010

Support-Based Distributed Optimisation: An Approach To Radiotherapy Patient Scheduling, Graham Billiau, Chee-Fon Chang, Andrew Alexis Miller, Aditya K. Ghose

Faculty of Informatics - Papers (Archive)

In the health system inefficiency leads to poor use of scarce expensive resources. Lengthy patient treatment waiting time can result from inefficiency in scheduling. The use of state-of-the art multi-agent and distributed computing technologies can provide a solution to address this problem. However, distributed optimisation in such a multi-agent setting poses an important challenge that requires protocols to enable agents to optimise shared objectives without necessarily revealing all of their private constraints. In this study we show that if the problem is expressed as a Dynamic Distributed Constraint Optimisation Problem a powerful algorithm such as SBDO can be deployed to …


The Detection Of Steam Injection Based On Video Surveillance, Yipeng Guo, Shu Wang, Ming Zhu, Jiangtao Xi Jan 2010

The Detection Of Steam Injection Based On Video Surveillance, Yipeng Guo, Shu Wang, Ming Zhu, Jiangtao Xi

Faculty of Informatics - Papers (Archive)

In this paper, we focus on the visual features of steam injection and propose an integrated algorithm to detect it based on video surveillance. The proposed method is depended on three decision rules which are the attribute of gray level and the feature of frequent flicker rate of steam injection, and the similarity structure between background image and current frame. The block-based approach is applied to all three decision rules. The experimental results show that the algorithm provides a reliable detection method which is useful in many cases such as the alarm on the leakage of a heating pipe.


Reflecting On Ontologies Towards Ontology-Based Agent-Oriented Software Engineering, Ghassan Beydoun, Brian Henderson-Sellers, Jun Shen, G. Low Jan 2009

Reflecting On Ontologies Towards Ontology-Based Agent-Oriented Software Engineering, Ghassan Beydoun, Brian Henderson-Sellers, Jun Shen, G. Low

Faculty of Informatics - Papers (Archive)

“Ontology” in association with “software engineering” is becoming commonplace. This paper argues for the need to place ontologies at the centre of the software development lifecycle for multi agent systems to enhance reuse of software workproducts as well as to unify agent-based software engineering knowledge. The paper bridges the state-of-the-art of ontologies research from Knowledge Engineering (KE) within Artificial Intelligence and Metamodelling within Software Engineering (SE). It presents a sketch of an ontology-based Multi Agent System (MAS) methodology discussing key roles on ontologies and their impact of workproducts, illustrating these in a MAS software development project for an important application …


Voltage Quality Behaviour Of A Wind Turbine Based Remote Area Power System, Nishad Mendis, Kashem Muttaqi, Sarath Perera Jan 2009

Voltage Quality Behaviour Of A Wind Turbine Based Remote Area Power System, Nishad Mendis, Kashem Muttaqi, Sarath Perera

Faculty of Informatics - Papers (Archive)

The power quality behaviour of a Remote Area Power System (RAPS) consisting of a Doubly Fed Induction Generator (DFIG), its main loads and a dummy load is presented in this paper. The dummy load is used to maintain the power balance of the system under changing wind and loading conditions. The performance of the remote area power system subject to various loading conditions has been evaluated in terms of the voltage quality, an aspect which has not received much attention in the past. The existing Distributed Generation (DG) power quality standards are taken as the basis to compare the voltage …


A Car Detection System Based On Hierarchical Visual Features, Fok Hing Chi Tivive, Abdesselam Bouzerdoum Jan 2009

A Car Detection System Based On Hierarchical Visual Features, Fok Hing Chi Tivive, Abdesselam Bouzerdoum

Faculty of Informatics - Papers (Archive)

In this paper, we address the problem of detecting and localizing cars in still images. The proposed car detection system is based on a hierarchical feature detector in which the processing units are shunting inhibitory neurons. To reduce the training time and complexity of the network, the shunting inhibitory neurons in the first layer are implemented as directional nonlinear filters, whereas the neurons in the second layer have trainable parameters. A multi-resolution processing scheme is implemented so as to detect cars of different sizes, and to reduce the number of false positives during the detection stage, an adaptive thresholding strategy …


Gremo: A Gis-Based Generic Model For Estimating Relative Wave Exposure, Austen Pepper, Marjetta L. Puotinen Jan 2009

Gremo: A Gis-Based Generic Model For Estimating Relative Wave Exposure, Austen Pepper, Marjetta L. Puotinen

Faculty of Science - Papers (Archive)

Wave exposure plays a major role in shaping the ecological structure of nearshore communities, with different community types able to survive and/or thrive when typically exposed to different levels of wave energy. This can be quantified by taking direct field measurements with wave buoys over time and then manipulating the data to derive typical conditions. However, taking these measurements is only feasible for very limited areas due to logistical constraints, and generating them with numerical wave models can also be expensive to run and may require data inputs that are either lacking or are highly uncertain. Instead, the relative differences …


Development Of Non-Antibiotic-Resistant, Chromosomally Based, Constitutive And Inducible Expression Systems For Aroa-Attenuated Salmonella Enterica Serovar Typhimurium, Jake Matic, Tamsin D. Terry, David Van Bockel, Tracy A. Maddocks, David Tinworth, Michael Jennings, Steven P Djordjevic, Mark J. Walker Jan 2009

Development Of Non-Antibiotic-Resistant, Chromosomally Based, Constitutive And Inducible Expression Systems For Aroa-Attenuated Salmonella Enterica Serovar Typhimurium, Jake Matic, Tamsin D. Terry, David Van Bockel, Tracy A. Maddocks, David Tinworth, Michael Jennings, Steven P Djordjevic, Mark J. Walker

Faculty of Science - Papers (Archive)

Live-vaccine delivery systems expressing two model antigens from Mycoplasma hyopneumoniae, F2(P97) (Adh) and NrdF, were constructed using Salmonella enterica serovar Typhimurium aroA (STM-1), and immunogenicity in mice was evaluated. Recombinant plasmid-based expression (PBE) and chromosomally based expression (CBE) systems were constructed. The PBE system was formed by cloning both antigen genes into pJLA507 to create an operon downstream of temperature-inducible promoters. Constitutive CBE was achieved using a promoter-trapping technique whereby the promoterless operon was stably integrated into the chromosome of STM-1, and the expression of antigens was assessed. The chromosomal position of the operon was mapped in four clones. Inducible …


A Simulation Study On The Energy Efficiency Of Pure And Slotted Aloha Based Rfid Tag Reading Protocols, Alejandro Ruiz-Rivera, Dheeraj Klair, Kwan-Wu Chin Jan 2009

A Simulation Study On The Energy Efficiency Of Pure And Slotted Aloha Based Rfid Tag Reading Protocols, Alejandro Ruiz-Rivera, Dheeraj Klair, Kwan-Wu Chin

Faculty of Informatics - Papers (Archive)

This paper studies the energy efficiency of twelve Pure and Slotted Aloha tag reading protocol variants via simulation. We compare their energy consumption in three collision resolution phases: 1) success, 2) collision, and 3) idle. Our extensive simulation results show that Pure Aloha with fast mode and muting has the lowest energy consumption, and hence is most suited for deployment in energy-constrained environments.


Adaptive Task Allocation For P2p-Based E-Services Composition, Jun Shen, Shuai Yuan Jan 2008

Adaptive Task Allocation For P2p-Based E-Services Composition, Jun Shen, Shuai Yuan

Faculty of Informatics - Papers (Archive)

To effectively manage the task allocation, especially when handling with numerous different peers’ qualities, is one of the greatest challenges to be faced in order to guarantee the success of P2P-based e-services composition. In this context, various QoS descriptive frameworks and Web services technologies (such as WSDL and BPEL) are being considered as the most affordable solutions to promote the performance of decentralized e-services, through applying strategies like QoS ontologies and related optimization algorithms globally or locally. Nonetheless, most P2P-based service selection and composition approaches applied nowadays lack dynamism and autonomy. In this paper, we first propose an extension of …


Feature Based Stereo Correspondence Using Moment Invariant, Prashan Premaratne, Farzad Safaei Jan 2008

Feature Based Stereo Correspondence Using Moment Invariant, Prashan Premaratne, Farzad Safaei

Faculty of Informatics - Papers (Archive)

Autonomous navigation is seen as a vital tool in harnessing the enormous potential of Unmanned Aerial Vehicles (UAV) and small robotic vehicles for both military and civilian use. Even though, laser based scanning solutions for Simultaneous Location And Mapping (SLAM) is considered as the most reliable for depth estimation, they are not feasible for use in UAV and land-based small vehicles due to their physicalsize and weight. Stereovision is considered as the best approach for any autonomous navigation solution as stereo rigs are considered to be lightweight and inexpensive. However, stereoscopy which estimates the depth information through pairs of stereo …


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 …


Construction Of Universal Designated-Verifier Signatures And Identity-Based Signatures From Standard Signatures, Siamak Fayyaz Shahandashti, Reihaneh Safavi-Naini Jan 2008

Construction Of Universal Designated-Verifier Signatures And Identity-Based Signatures From Standard Signatures, Siamak Fayyaz Shahandashti, Reihaneh Safavi-Naini

Faculty of Informatics - Papers (Archive)

We give a generic construction for universal designated-verifier signature schemes from a large class, C, of signature schemes. The resulting schemes are efficient and have two important properties. Firstly, they are provably DV-unforgeable, non-transferable and also non-delegatable. Secondly, the signer and the designated verifier can independently choose their cryptographic settings. We also propose a generic construction for identity-based signature schemes from any signature scheme in C and prove that the construction is secure against adaptive chosen message and identity attacks. We discuss possible extensions of our constructions to universal multi-designated-verifier signatures, hierarchical identity-based signatures, identity-based universal designated verifier signatures, and …


A Provable Secure Id-Based Explicit Authenticated Key Agreement Protocol Without Random Oracles, Haibo Tian, Willy Susilo, Yang Ming, Yumin Wang Jan 2008

A Provable Secure Id-Based Explicit Authenticated Key Agreement Protocol Without Random Oracles, Haibo Tian, Willy Susilo, Yang Ming, Yumin Wang

Faculty of Informatics - Papers (Archive)

In this paper, we present an identity-based explicit authenticated key agreement protocol that is provably secure without random oracles. The protocol employs a new method to isolate a session key from key con¯rmation keys so that there is no direct usage of hash functions in the protocol. The protocol is proved secure without random oracles in a variant of Bellare and Rogaway style model, an exception to current proof method in this style model in the ID-based setting. We believe that this key isolation method is novel and can be further studied for constructing more e±cient protocols.


Antimycobacterial Activity Of Cinnamate-Based Esters Of The Triterpenes Betulinic, Oleanolic And Ursolic Acids, Tanud Tanachatchairatana, John B. Bremner, Ratchanaporn Chokchaisiri, Apichart Suksamrarn Jan 2008

Antimycobacterial Activity Of Cinnamate-Based Esters Of The Triterpenes Betulinic, Oleanolic And Ursolic Acids, Tanud Tanachatchairatana, John B. Bremner, Ratchanaporn Chokchaisiri, Apichart Suksamrarn

Faculty of Science - Papers (Archive)

Betulinic acid, oleanolic acid and ursolic acid have been modified at the C-3 position to cinnamate-based esters and in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Ra has been determined. The results indicated that modification of the parent structures of betulinic acid, oleanolic acid and ursolic acid to the p-coumarate and, in the case of the latter two triterpenes, the ferulate ester analogues resulted in high antimycobacterial activity. Structure–activity relationships within the lupane, oleanane and ursane analogues and between these triterpenes are discussed.


Validation Of Ace-Fts V2.2 Measurements Of Hci, Hf, Cci3f And Cci2f2 Using Space-, Balloons- And Ground-Based Instrument Observations, E Mahieu, P Duchatelet, P Demoulin, L Froidevaux, C Randall, Nicholas B. Jones, David W. Griffith, G C. Toon, J-F Blavier, C P Rinsland, R Zander, S Wood, M De Maziere, T Blumenstock, A. Kagawa, J Hannigan, M Coffey, F Hase, D Smale, K Strong, J R. Taylor, Thorsten Warneke, Y Kasai, E Dupuy, V Catoire, C Robert, C Senten, C Tetard, K W. Jucks, C Boone, S Mikuteit, K A. Walker, P Bernath, O Schrems, Y Mebarki, R Nassar, C Servais, Justus Notholt Jan 2008

Validation Of Ace-Fts V2.2 Measurements Of Hci, Hf, Cci3f And Cci2f2 Using Space-, Balloons- And Ground-Based Instrument Observations, E Mahieu, P Duchatelet, P Demoulin, L Froidevaux, C Randall, Nicholas B. Jones, David W. Griffith, G C. Toon, J-F Blavier, C P Rinsland, R Zander, S Wood, M De Maziere, T Blumenstock, A. Kagawa, J Hannigan, M Coffey, F Hase, D Smale, K Strong, J R. Taylor, Thorsten Warneke, Y Kasai, E Dupuy, V Catoire, C Robert, C Senten, C Tetard, K W. Jucks, C Boone, S Mikuteit, K A. Walker, P Bernath, O Schrems, Y Mebarki, R Nassar, C Servais, Justus Notholt

Faculty of Science - Papers (Archive)

Hydrogen chloride (HCl) and hydrogen fluoride (HF) are respectively the main chlorine and fluorine reservoirs in the Earth's stratosphere. Their buildup resulted from the intensive use of man-made halogenated source gases, in particular CFC-11 (CCl3F) and CFC-12 (CCl2F2), during the second half of the 20th century. It is important to continue monitoring the evolution of these source gases and reservoirs, in support of the Montreal Protocol and also indirectly of the Kyoto Protocol. The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) is a space-based instrument that has been performing regular solar occultation measurements of …


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 …


Bi-2212 Based Anode Materials For Li-Ion Batteries, Matthew Lindsay, Hua-Kun Liu Jan 2007

Bi-2212 Based Anode Materials For Li-Ion Batteries, Matthew Lindsay, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

A number of studies have previously examined the insertion of lithium into superconductor Bi2Sr2CaCu2O8+δ(Bi-2212) materials. A maximum lithium uptake of two moles of lithium per mole of Bi-2212 was reported amongst these studies which corresponds to a capacity of 60 mAh/g. Two Bi-2212 materials are examined here an undoped Bi2Sr2CaCu2O8+δ and doped Bi2Sr2Ca0.3Y0.7Cu2O8 material. Both materials exhibitied a capacity of over 60 mAh/g in both the as produced stated and whn subjected to further …


Long-Term Tropospheric Formaldehyde Concentrations Deduced From Ground-Based Fourier Transform Solar Infrared Measurements, Nicholas B. Jones, K Riedel, Barbara M. Allen, S. W. Wood, Paul Palmer, K Chance, Justus Notholt Jan 2007

Long-Term Tropospheric Formaldehyde Concentrations Deduced From Ground-Based Fourier Transform Solar Infrared Measurements, Nicholas B. Jones, K Riedel, Barbara M. Allen, S. W. Wood, Paul Palmer, K Chance, Justus Notholt

Faculty of Science - Papers (Archive)

We report a 13-year (1992–2005) dataset of total column measurements of formaldehyde (HCHO) over Lauder, New Zealand, inferred from solar infrared spectra measured using a high-resolution Fourier Transform Spectrometer (FTS). Ambient HCHO concentrations at this rural location are often close to levels typical of remote marine environments (<250 ppt), which are close to the detection limit using standard techniques. Consequently we develop a new method that successfully produces HCHO columns with sufficient sensitivity throughout the whole season. HCHO columns over Lauder have a strong seasonal cycle (±50%), with a mean column of 4.9×1015 molecules cm−2, peaking during summer months. A simple box model of CH4 oxidation reproduces the observed broad-scale seasonal cycle, but significantly underestimates the seasonal peak HCHO ground concentrations during summer. This suggests the existence of an additional significant source of HCHO, possibly isoprene that cannot be explained by oxidation of CH4 alone. The ground-based FTS column data compare well with collocated HCHO column measurements from the Global Ozone Monitoring Experiment (GOME) satellite instrument during the operational period of GOME (1996–2001, r2=0.65, mean bias=10%, n=48).


Ground-Based Solar Absorption Ftir Spectroscopy: Characterization Of Retrievals And First Results From A Novel Optical Design Instrument At A New Ndacc Complementary Station, Aldona Waiacek, J R. Taylor, K Strong, R Saari, T Kertzenmacher, Nicholas B. Jones, David W. Griffith Jan 2007

Ground-Based Solar Absorption Ftir Spectroscopy: Characterization Of Retrievals And First Results From A Novel Optical Design Instrument At A New Ndacc Complementary Station, Aldona Waiacek, J R. Taylor, K Strong, R Saari, T Kertzenmacher, Nicholas B. Jones, David W. Griffith

Faculty of Science - Papers (Archive)

The authors describe the optical design of a high-resolution Fourier Transform Spectrometer (FTS), which serves as the primary instrument at the University of Toronto Atmospheric Observatory (TAO). The FTS is dedicated to ground-based infrared solar absorption atmospheric measurements from Toronto, Ontario, Canada. Instrument performance is discussed in terms of instrumental line shape (ILS) and phase error and modulation efficiency as a function of optical path difference. Typical measurement parameters are presented together with retrieval parameters used to derive total and partial column concentrations of ozone. Retrievals at TAO employ the optimal estimation method (OEM), and some impacts of the necessary …