Physical Sciences and Mathematics Commons^™

A Review Of Recent Investigations With Reference To Iec/Tr 61000-3-13 On Voltage Unbalance Emission Allocation, Prabodha Paranavithana, Upuli Jayatunga, Sarath Perera, Philip Ciufo

Faculty of Informatics - Papers (Archive)

The Technical Report IEC/TR 61000-3-13:2008 provides guiding principles for coordinating voltage unbalance between various voltage levels of a power system through the allocation of emission limits to installations. This report is based on widely accepted concepts and principles in relation to voltage unbalance. With regard to some of the key ideas used in this report, investigations have been carried out which have enabled the development of deeper insights making the voltage unbalance allocation process more comprehensive. The key aspects which have been considered in detail include: voltage unbalance which arises as a result of lines and voltage unbalance propagation in …

Introducing Power System Voltage Droop As A New Concept For Harmonic Current Allocation, Robert A. Barr, V. J. Gosbell

Faculty of Informatics - Papers (Archive)

“Voltage Droop” is a new concept that has been developed primarily for use in the harmonic current allocation process. Voltage droop offers the opportunity to both vastly simplify the procedures required by the present IEC 61000.3.6 [1] guidelines for Stage 2 allocation and provide a solid theoretical base to this work. The voltage droop concept has also been found to provide a usefull theoretical basis for the harmonic standard IEEE 519[2]. While this paper develops the voltage droop concept using diagrams and words, the companion paper “Harmonic Allocation Following IEC Guidelines Using the Voltage Droop Concept”[3] contains a full critical …

Ontology Modeling Of Ubl Process Diagrams Using Owl, Suman Roy, Kiran Prakash Sawant, Aditya K. Ghose

Faculty of Informatics - Papers (Archive)

We present a logical framework for modeling Universal Business Language (UBL) processes. The proposed framework provides a representation of the dynamic world being modeled on the user supplied axioms about preconditions and the initial state of the world, and produces a workflow specification at a higher level of abstraction. We use the Frieghtbilling process of the UBL as a case study for our experiment. Further we extract ontology from the associated UBL document that can ensure efficient information retrieval, discovery and auditing. We use the popular semantic web formalism, Web Ontology Language (OWL) for ontology construction purposes. These domain ontologies …

What's Your Contribution? An Online System For Assessing Each Member's Participation In Team Based Projects, Peter James Vial, Zhihao Zhang, Montserrat Ros, Christian Ritz, Geoffrey W. Trott

Faculty of Informatics - Papers (Archive)

Team based subjects in Engineering occur within the School of Electrical, Computer and Telecommunications Engineering in second and third year undergraduate degrees. In such subjects, students work in teams of between five and ten students to propose and develop engineered products for a target market place (chosen from different themes) with a small budget allocated for purchasing materials and devices. In practice, all students cannot make exactly the same contribution as each other, so a system to allocate marks for individual's contribution has been previously developed and employed within the school. This system is called the Fair Contribution Sheet (FCS) …

Hybrid Operation Of Wind-Diesel-Fuel Cell Remote Area Power Supply System, Nishad Mendis, Kashem Muttaqi, Saad Sayeef, Sarath Perera

Faculty of Informatics - Papers (Archive)

Due to the uncertainties associated with wind profiles, the load side voltage and frequency control of a wind dominated Remote Area Power Supply (RAPS) system is a challenging task. The performance of such a wind dominated hybrid RAPS system consisting of a diesel generator, fuel cell system, dump load and mains load is investigated in this paper. Integrating a fuel cell into the RAPS system enables the diesel usage to be kept at its minium level while avoiding operation of the diesel generator at low load factor. The diesel generator is used to provide the reactive power requirement of the …

Desired And Received Customer Value Models In Logistics Service Outsourcing, Yeni Sumantri, Sim Kim Lau

Faculty of Informatics - Papers (Archive)

The customer value literature offers diverse meanings of customer value concept. The significant differences among these meanings rest on interpretation or understanding of customer value. Generally, there are two major concepts of customer value. The first is desired value and the second is received value. Desired value refers to the value that customer wants to receive from product-vendor-customer interactions. Received value refers to the value that is actually experienced through product-vendor-customer interactions. Majority of research tends to focus on the received value concept. Although these two concepts are complementary, no research investigating both concepts has been conducted. This paper explores …

Control Coordination Of A Wind Turbine Generator And A Battery Storage Unit In A Remote Area Power Supply System, Nishad Mendis, Kashem Muttaqi, Saad Sayeef, Sarath Perera

Faculty of Informatics - Papers (Archive)

A novel hybrid Remote Area Power Supply (RAPS) system consisting of a Doubly Fed Induction Generator (DFIG) based wind turbine and a battery Energy Storage System (ESS) is investigated in this paper. The proposed RAPS system also consists of a dummy load and its controller. The battery energy storage system is used as a buffer which is connected to the DC link of the DFIG. The dummy load which is connected to the AC side of the system is used to absorb the energy associated with over generation, a situation which cannot be handled through the battery system. Control coordination …

Preliminary Sample Design For The New Zealand Health Survey 2010, Robert Graham Clark

Faculty of Informatics - Papers (Archive)

This report describes the choice of the preliminary design for the New Zealand Health Survey, to be implemented from 2011. The survey will use computer assisted personal interviewing. The sample will be selected using a multi-stage area design. The selected sample size will be around 12,000 people per year. This is envisaged as sufficient to provide adequate precision for estimates of key prevalences for adults and children. The main objectives of the sample design are: • The design should support analysis of the survey by multiple users, which implies avoiding great variation in estimation weights. • Estimates for children and …

Definition Of A Description Language For Business Service Decomposition, Lam-Son Le, Aditya K. Ghose, Evan D. Morrison

Faculty of Informatics - Papers (Archive)

In the last few years, service-oriented computing has become an emerging research topic in response to the shift from product-oriented economy to service-oriented economy and the move from focusing on software/system development to addressing business-IT alignment. From an IT perspective, there is a proliferation of methods and languages for describing Web services. There has not been as much work in defining languages or ontologies for describing services from business perspectives. In this paper, we analyze the landscape of service representation and discuss the needs of having a description language for business services. By leveraging existing work on describing service capabilities …

Strategy Representation Using An I*-Like Notation, Lam-Son Le, Bingyu Zhang, Aditya K. Ghose

Faculty of Informatics - Papers (Archive)

Assessing and achieving alignment between an organization’s strategies and its IT/business functions has long been recognized as a critically important question. This paper reports on a project that seeks to overturn established management orthodoxy by establising that strategies can be adequately modeled using conceptual modeling notations and that methodological and tool support can be provided for the task of assessing and achieving alignment between the strategies of an organization and its service offerings. A key element of this enterprise has been the design of SML - the Strategy Modeling Language. This paper presents an interim report from this project that …

Efficient Svm Training With Reduced Weighted Samples, Son Lam Phung, Giang Hoang Nguyen, Abdesselam Bouzerdoum

Faculty of Informatics - Papers (Archive)

This paper presents an efficient training approach for support vector machines that will improve their ability to learn from a large or imbalanced data set. Given an original training set, the proposed approach applies unsupervised learning to extract a smaller set of salient training exemplars, which are represented by weighted cluster centers and the target outputs. In subsequent supervised learning, the objective function is modified by introducing a weight for each new training sample and the corresponding penalty term. In this paper, we investigate two methods of defining the weight based on cluster vectors. The proposed SVM training is implemented …

A Particle Swarm Optimization Algorithm Based On Orthogonal Design, Jie Yang, Abdesselam Bouzerdoum, Son Lam Phung

Faculty of Informatics - Papers (Archive)

The last decade has witnessed a great interest in using evolutionary algorithms, such as genetic algorithms, evolutionary strategies and particle swarm optimization (PSO), for multivariate optimization. This paper presents a hybrid algorithm for searching a complex domain space, by combining the PSO and orthogonal design. In the standard PSO, each particle focuses only on the error propagated back from the best particle, without “communicating” with other particles. In our approach, this limitation of the standard PSO is overcome by using a novel crossover operator based on orthogonal design. Furthermore, instead of the “generating-and-updating” model in the standard PSO, the elitism …

Adaptive Hierarchical Architecture For Visual Recognition, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Son Lam Phung, Khan M. Iftekharuddin

Faculty of Informatics - Papers (Archive)

We propose a new hierarchical architecture for visual pattern classification. The new architecture consists of a set of fixed, directional filters and a set of adaptive filters arranged in a cascade structure. The fixed filters are used to extract primitive features such as orientations and edges that are present in a wide range of objects, whereas the adaptive filters can be trained to find complex features that are specific to a given object. Both types of filters are based on the biological mechanism of shunting inhibition. The proposed architecture is applied to two problems: pedestrian detection and car detection. Evaluation …

Automatic Human Motion Classification From Doppler Spectrograms, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Moeness G. Amin

Faculty of Informatics - Papers (Archive)

No abstract provided.

Motion Estimation With Adaptive Regularization And Neighborhood Dependent Constraint, Muhammad Wasim Nawaz, Abdesselam Bouzerdoum, Son Lam Phung

Faculty of Informatics - Papers (Archive)

Modern variational motion estimation techniques use total variation regularization along with the L1 norm in constant brightness data term. An algorithm based on such homogeneous regularization is unable to preserve sharp edges and leads to increased estimation errors. A better solution is to modify regularizer along strong intensity variations and occluded areas. In addition, using neighborhood information with data constraint can better identify correspondence between image pairs than using only a pointwise data constraint. In this work, we present a novel motion estimation method that uses neighborhood dependent data constraint to better characterize local image structure. The method also uses …

Automatic Recognition Of Smiling And Neutral Facial Expressions, Peiyao Li, S L. Phung, Abdesselam Bouzerdoum, Fok Hing Chi Tivive

Faculty of Informatics - Papers (Archive)

Facial expression is one way humans convey their emotional states. Accurate recognition of facial expressions via image analysis plays a vital role in perceptual human computer interaction, robotics and online games. This paper focuses on recognising the smiling from the neutral facial expression. We propose a face alignment method to address the localisation error in existing face detection methods. In this paper, smiling and neutral facial expression are differentiated using a novel neural architecture that combines fixed and adaptive non-linear 2-D filters. The fixed filters are used to extract primitive features, whereas the adaptive filters are trained to extract more …

Fpga-Based Signal Processing In An Optical Feedback Self-Mixing Interferometry System, Zongzhen Li, Yanguang Yu, Jiangtao Xi, Huiying Ye

Faculty of Informatics - Papers (Archive)

Optical feedback Self-mixing Interferometry (OFSMI) can achieve a high-resolution displacement sensing and measurement by using advanced digital signal processing. However, most existing signal processing algorithms used for OFSMI signals are implemented on a PC by Matlab or other programming languages. In this case, the whole structure of OFSMI sensing system is incompact and the measurement is in low speed. The design trends in sensing systems are towarding to small size, high integration and fast real time processing. These trends require us to improve the existing OFSMI design. It is a good solution to apply Field-programmable gate arrays (FPGAs) technique onto …

Inter-Domain Routing Validator Based Spoofing Defence System, Lei Wang, Tianbing Xia, Jennifer Seberry

Faculty of Informatics - Papers (Archive)

IP spoofing remains a problem today in the Internet. In this paper, a new system called Inter-Domain Routing Validator Based Spoofing Defence System (SDS) for filtering spoofed IP packets is proposed . SDS uses efficient symmetric key message authentication code (UMAC) as its tag to verify that a source IP address is valid. Different ASes border routers obtain a shared key via the Inter-Domain Routing Validator (IRV) servers which will manage the secret keys and exchange keys among different ASes via security communication channel. SDS is efficient, secure and easy to cooperate with other defence mechanisms.

Differential Fault Analysis Of Lex, Jianyong Huang, Willy Susilo, Jennifer Seberry

Faculty of Informatics - Papers (Archive)

LEX is a stream cipher based on the round transformation of the AES block cipher, and it was selected for the final phase evaluation of the eSTREAM project. LEX is 2.5 times faster than AES both in software and in hardware. In this paper, we present a differential fault attack on LEX. The fault model assumes that the attacker is able to flip a random bit of the internal state of the cipher but cannot control the exact location of the induced fault. Our attack requires 40 faults, and recovers the secret key with 216 operations.

Social Tagging For Digital Libraries Using Formal Concept Analysis, Timothy Wray, Peter W. Eklund

Faculty of Informatics - Papers (Archive)

This paper describes the Art Collection Ecosystem – an application that allows users to tag and serendipitously browse content using Formal Concept Analysis. Within this application, tags are derived from meta-data of artworks within an existing asset management system and are classified according to theories derived from social tagging behaviour.We present past and recent iterations of its design, where it is evaluated as a contextual comparison to a popular image tagging application, Flickr. Through the process of iterative design and user evaluation, we produce results are of interest to any applied research and development that involves the exploration of digital …

Estimating Shared Copy Number Aberrations For Array Cgh Data: The Linear-Median Method, Yan-Xia Lin, Veera Baladandayuthapani, V Bonato, K.-A. Do

Faculty of Informatics - Papers (Archive)

Motivation: Existing methods for estimating copy number variations in array comparative genomic hybridization (aCGH) data are limited to estimations of the gain/loss of chromosome regions for single sample analysis. We propose the linear-median method for estimating shared copy numbers in DNA sequences across multiple samples, demonstrate its operating characteristics through simulations and applications to real cancer data, and compare it to two existing methods.

Results: Our proposed linear-median method has the power to estimate common changes that appear at isolated single probe positions or very short regions. Such changes are hard to detect by current methods. This new …

Probabilistic Neural Network For Vulnerability Prediction On A Practical Power System, Ahmed Haidar, Zulkeflee Khalidin, Ibrahim Abdulrab Ahmed

Faculty of Informatics - Papers (Archive)

Vulnerability prediction of power systems is important so as to determine its ability to continue to provide service in case of any unforeseen catastrophic contingency. It is considered one of the vital concerns due to the continual blackouts in recent years which indicate that the power system today is too vulnerable to withstand a severer disturbance. The objective of this paper is to investigate and compare the performance of two vulnerability indices used for assessing the vulnerability of power systems when subjected to various contingencies. The Probabilistic Neural Network (PNN) based on power system loss and possible loss of load …

A Longer Look At The Asymmetric Dependence Between Hedge Funds And The Equity Market, Byoung Kang, Francis In, Gunky Kim, Tong Kim

Faculty of Informatics - Papers (Archive)

This paper reexamines, at a range of investment horizons, the asymmetric dependence between hedge fund returns and market returns. Given the current availability of hedge fund data, the joint distribution of longer-horizon returns is extracted from the dynamics of monthly returns using the filtered historical simulation; we then apply the method based on copula theory to uncover the dependence structure therein. While the direction of asymmetry remains unchanged, the magnitude of asymmetry is attenuated considerably as the investment horizon increases. Similar horizon effects also occur on the tail dependence. Our findings suggest that nonlinearity in hedge fund exposure to market …

Analysis Of A Model For Ethanol Production Through Continuous Fermentation: Ethanol Productivity, Simon Watt, Harvinder Sidhu, Mark Nelson, Ajay Ray

Faculty of Informatics - Papers (Archive)

We investigate a model for the production of ethanol through continuous fermentation using Saccharomyces cerevisiae in a single reactor and cascades of up to five reactors. Using path-following methods we investigate how the ethanol productivity varies with the residence time in each reactor of the cascade. With a substrate feed concentration of 160 g/l we find the optimal productivity is 3.80 g/l/h, 5.08 g/l/h, and 5.18 g/l/h in a single reactor, a double reactor cascade and a triple reactor cascade respectively. For the case of a cascade containing reactors of equal size we investigate reactor configurations of up to five …