Digital Commons Network^™

Solution Of The Navier-Stokes Equations For Transonic Propeller Flows, Fergal Boyle

Conference Papers

The three-dimensional, compressible, viscous flow field around a general propeller geometry with the inflow at zero angles of incidence and yaw is computed using a Reynolds-Averaged Navier-Stokes equations solver. Results from validation test cases in which the laminar and turbulent incompressible flow over a flat plate are calculated demonstrate the flow solver is capable of accurately capturing boundary-layer behaviour. Euler solutions from flow field calculations around two very different propeller geometries show a high level of accuracy and efficiency. Preliminary results from a viscous flow field calculation around a two-bladed propeller are very encouraging.

The Dogs Bollox, Special War Edition, Vol. 1, Issue 2, 2003, Dit: Students' Union

DIT Student Union

No abstract provided.

Formal Concept Matching And Reinforcement Learning In Adaptive Information Retrieval, Rohana Kithsiri Rajapakse

School of Engineering, Computing and Mathematics Theses

The superiority of the human brain in information retrieval (IR) tasks seems to come firstly from its ability to read and understand the concepts, ideas or meanings central to documents, in order to reason out the usefulness of documents to information needs, and secondly from its ability to learn from experience and be adaptive to the environment. In this work we attempt to incorporate these properties into the development of an IR model to improve document retrieval. We investigate the applicability of concept lattices, which are based on the theory of Formal Concept Analysis (FCA), to the representation of documents. …

A Correlation Framework For Continuous User Authentication Using Data Mining, Harjit Singh

School of Engineering, Computing and Mathematics Theses

The increasing security breaches revealed in recent surveys and security threats reported in the media reaffirms the lack of current security measures in IT systems. While most reported work in this area has focussed on enhancing the initial login stage in order to counteract against unauthorised access, there is still a problem detecting when an intruder has compromised the front line controls. This could pose a senous threat since any subsequent indicator of an intrusion in progress could be quite subtle and may remain hidden to the casual observer. Having passed the frontline controls and having the appropriate access privileges, …

Intelligent Vision-Based Navigation System, Kheng Lee Koay

School of Engineering, Computing and Mathematics Theses

This thesis presents a complete vision-based navigation system that can plan and follow an obstacle-avoiding path to a desired destination on the basis of an internal map updated with information gathered from its visual sensor. For vision-based self-localization, the system uses new floor-edges-specific filters for detecting floor edges and their pose, a new algorithm for determining the orientation of the robot, and a new procedure for selecting the initial positions in the self-localization procedure. Self-localization is based on matching visually detected features with those stored in a prior map. For planning, the system demonstrates for the first time a real-world …

Writing Centers And Writing-Across-The Curriculum: An Important Connection, Carol Peterson Haviland

The Writing Center Journal

No abstract provided.

Reassessing The "Proofreading Trap": Esl Tutoring And Writing Instruction, Sharon A. Myers

The Writing Center Journal

No abstract provided.

Destination Cuba, Tim Obermiller

Illinois Wesleyan University Magazine, 2002-2017

Illinois Wesleyan students explore the contradictions of a nation on the brink of change.

Searching For Greater Variety In Strategic Thinking, Brendan O'Rourke, Martyn Pitt

Conference papers

This paper proposes a use of the discursive approach to explicate variety in ways of strategic thinking. Such an explication of variety is both useful managerially in increasing awareness of greater discursive resources and also theoretically in critiquing views of strategic thinking as homogenous and organizationally contained. Ways of strategic thinking have been investigated using a variety of approaches including expertise perspectives (Voss, Greene et al. 1983), cognitive mapping (Eden, Jones et al. (1979); Huff (1990) ) and upper echelon theory (Hambrick 1998). More recently the linguistic turn in organizational sciences (Alvesson and Kärreman 2000), and the study of strategy …

Retailing At The Periphery: An Analysis Of Dublin’S Tertiary City-Centre Shopping Streets (1972-2002), Edmund O'Callaghan, Don O'Riordan

Articles

This research examined changes in Dublin’s tertiary city centre shopping streets over a thirty year period to 2002. An observational study of the occupancy of the city’s tertiary streetscape was undertaken in the summer of 2002 and compared with historical data. Results indicate significant change over the period examined: an increased vacancy rate, a very low survival rate, a considerable incidence of non retail specific activities, a decline in traditional retail offerings and the emergence of new categories of retailer. The paper concludes by suggesting a proactive approach is required by present day retailers in the tertiary streets to ensure …

The Implications Of The Curriculum Process On The Design Of A Modern Engineering Programme In The Dublin Institute Of Technology, Kevin Kelly

Level 3

In the Dublin Institute of Technology (DIT) the curriculum usually starts with a programme document. The programme document will be a snapshot of faculty thinking at a point in time, usually at the validation stage of the programme. The programme document lays down clearly the aims, objectives, facilities, staff, syllabi, learning/teaching methods, assessment procedures, programme-management arrangements and all of the other characteristics of the programme. It provides a basis for critical scrutiny by all involved. Compilation of the document is an iterative process, and the final document is scrutinised by an expert panel as part of the validation process.

Healthy Cities, Julie Gannon

Articles

No abstract provided.

Integrating The Use Of Teaching Portfolios With Experiential Learning In A Postgraduate Certificate For Academic Staff In Third Level Learning And Teaching, Roisin Donnelly

Journal Articles

No abstract provided.

Sharing Systems, Sharing Language: Designing And Working In A Virtual Department, Claire Mcavinia, Jane Hughes

Journal Articles

Less widely taught languages present special problems. Often students may be ab initio learners who must progress very rapidly from beginner to highly competent. Appropriate learning materials are scarce. Small student numbers restrict the range of learner tasks. To address these problems, and drawing on research methods from both CALL and Computer Science domains, we investigated the use of a virtual learning environment (WebCT) as a tool for collaborative language teaching and learning. A web-based virtual department was created, bringing students and tutors from different institutions together to practise the target language (students) and share the development of quality resources …

A Five-Channel, Single Detector, Emission Remote Sensor (Presentation), Mitchell J. Williams, Donald H. Stedman, Gary A. Bishop, Richard W. Quine

Fuel Efficiency Automobile Test Publications

No abstract provided.

2003 : Part-Time Programmes, Dublin Institute Of Technology

DIT Publications

Book containing information and full list of part - time courses for 2003 entry.

2003/2004 academic calendar.

Faculty structure and key contacts at DIT.

Enhanced Magnetoresistance In Nanocrystalline Magnetite, M Venkatesan, S. Nawka, Suresh Pillai, Jm D. Coey

Articles

The magnetic and magnetotransport properties of nanoparticulate magnetite with different grain
sizes are investigated using x-ray diffraction, microscopy, magnetometry, and magnetoresistance
measurements. The magnetization varies significantly with grain size and is sensitive to preparation conditions. The reduction in saturation magnetization in coprecipitated particles is probably due to the surface spin disorder. Magnetoresistance of pressed powder compacts is significantly enhanced
in material composed of small grain size magnetite particles prepared by coprecipitation. Useful
magnetoresistance persists well above room temperature in sintered ceramic material.

Comparison Of 3-, 5-, And 6-Phase Machines For Automotive Charging Applications, B. Zhang, Hua Bai, Walter Eversman, Ronald J. Krefta, Duane J. Buening, Steven Pekarek, Gregory R. Holbrook

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, the performance of a 5-phase claw-pole machine/converter system is compared with those of 3-phase and 6-phase systems of the same volume. It is shown that the acoustic output of the 5-phase machine compares favorably with that of the 6-phase machine and is much lower than that of the 3-phase machine over a majority of the operating range. In addition, the output current produced by the 5-phase machine Is, in general, 6-8% higher than those of the 3-phase and 6-phase machines. These results suggest that for maximizing power density while minimizing cost and acoustic noise, 5-phase machines provide …

Method Development Through Statistical Design For The Dependence Of Viscosity For Solutions Of Carboxymethylcellulose On Temperature, Concentration, And Dilution., Maryann E. Keene

Theses

Statistical method development is useful when expense, quantity of material, or time is limited, as experiment numbers are significantly reduced. The purpose of this study was to create a statistical model that explains the relationship between viscosity, temperature, concentration, and dilution due to bodily fluids in a pharmaceutical context of carboxymethylcellulose (CMC) solutions. The Graeco-Latin square design was employed to chose data points and Minitab® statistical software was used for data analysis. It was found in this model that concentration and dilution have the greatest effect on viscosity, while temperature has a lesser effect. It was also found that there …

Time Scale Modification Of Music Using A Subband Approach Based On The Bark Scale, David Dorran, Robert Lawlor

Conference papers

Time-domain time-scaling algorithms are efficient in comparison to their frequency-domain counterparts, but they rely upon the existence of a quasi-periodic signal to produce a high quality output. This requirement makes them unsuitable for use on multi-pitched signals such as polyphonic music. However, time-domain techniques applied on a subband basis can resolve the multi-pitch problem. The authors propose an improved subband implementation based upon the bark scale for the time scale modification of music. The new subband approach is supported by psychoacoustic and music theory and subjectively through informal listening tests.

An Efficient Audio Time-Scale Modification Algorithm For Use In A Subband Implementation, David Dorran, Robert Lawlor

Conference papers

The Paola algorithm, is an efficient algorithm for the time scale modification of speech. It uses a simple peak alignment technique to synchronise synthesis frames and takes waveform properties and the desired time-scale factor into account to determine optimum alogrithm parameters. However, PAOLA has difficulties with certain waveform types and can result in poor synchronisation for subband implementations. SOLA is a less efficient algorithm but resolves the issues associated with PAOLA's implementation. The authors present an algorithm that is a combination of the two approaches that proves to be an efficient and effective algorithm for a subband implementation.

Prior Subspace Analysis For Drum Transcription, Derry Fitzgerald, Robert Lawlor, Eugene Coyle

Conference papers

This paper introduces the technique of Prior Subspace Analysis (PSA) as an alternative to Independent Subspace Analysis (ISA) in cases where prior knowledge about the sources to be separated is available. The use of prior knowledge overcomes some of the problems associated with ISA, in particular the problem of estimating the amount of information required for separation. This results in improved robustness for drum transcription purposes. Prior knowledge is incorporated by use of a set of prior frequency subspaces that characterise features of the sources to be extracted. The effectiveness and robustness of PSA is demonstrated by its use in …

Time-Scale Modification Of Speech Using A Synchronised And Adaptive Overlap-Add (Saola) Algorithm, David Dorran, Robert Lawlor, Eugene Coyle

Conference papers

The synchonised overlap-add (SOLA) algorithm is a commercially popular and considerably researched audio time-scale modification technique. It operates in the time domain and uses a correlation technique to ensure that synthesis frames overlap in a synchronous manner. We present a modification to SOLA that allows the analysis step size adapt to the desired time-scale factor. The synchronised and adaptive overlap-add (SAOLA) alogorithm improves upon the output quality of SOLA for high time-scale factors and reduces the computational requirements for low time-scale factors. However, the computational requirements for high time-scale factors are increased.

Independent Subspace Analysis Using Locally Linear Embedding, Derry Fitzgerald, Eugene Coyle

Conference papers

While Independent Subspace Analysis provides a means of blindly separating sound souces from a single channel signal, it does have a number of problems. In particular the amount of information required for separation of sources varies with the signal. This is a result of the variance-based nature of Principal Component Analysis, which is used for dimensional reduction in the Independent Subspace Analysis algorithm. In an attempt to overcome this problem the use of a non-variance based dimensional reduction method, Locally Linear Embedding, is proposed. Locally Linear Embedding is a geometry based dimensional reduction technique. The use of this approach is …

Nnp “Nowhere Near Perfect”, Thomas Power

Other Resources

The aim of this essay is to examine two views and conclusions on the now commonly recognised inadequacies of Net National Product as an indicator of aggregate national well-being. It outlines Dasgupta’s simplified model of the effect of environmental losses on NNP and reviews Douthwaite’s treatment of NNP.

Drum Transcription Using Automatic Grouping Of Events And Prior Subspace Analysis, Derry Fitzgerald, Robert Lawlor, Eugene Dermot Coyle Professor

Conference papers

While Prior Subspace Analysis (PSA) has proved an effective tool for transcribung mixtures of snare, kick drum and hi-hat, attempts to extend it to increased numbers of drum types have met with mixed results. To overcome this an automatic grouping method has been developed to group drum events on their similarity in frequency content. Combined with PSA this creates a system able to handle robustly greater numbers of drum types. The effectiveness of this method is demonstrated in a drum transcription algorithm.

A Simulation Model To Characterize Photolithography Process Of A Semiconductor Wafer Fabrication, Amr Arisha, Paul Young, Mohie El Baradie

Articles

The pressures on semiconductor manufacturers due to cost considerations, rapid growth of process technology, quality constraints, feature size reduction, and increasingly complex products are requiring ever higher efficiency from manufacturing facilities. The complexity of manufacturing high capacity semiconductor devices means that it is impossible to analyze the process control parameters and the production configurations using traditional analytical models. There is, therefore, an increasing need for effective models of each manufacturing process, characterizing and analyzing the process in detail, allowing the effect of changes in the production environment on the process to be predicted. The photolithography process is one of the …

Sensor Networks: An Overview, Malik Tubaishat, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

Advances in hardware and wireless network technologies have created low-cost, low-power, multifunctional miniature sensor devices. These devices make up hundreds or thousands of ad hoc tiny sensor nodes spread across a geographical area. These sensor nodes collaborate among themselves to establish a sensing network. A sensor network can provide access to information anytime, anywhere by collecting, processing, analyzing and disseminating data. Thus, the network actively participates in creating a smart environment.

Rapid Measurement Of Indoor Mass-Transfer Coefficients, Glenn Morrison, Zhao Ping, Deborah J. Wiseman, Maneerat Ongwandee, Hong Chang, Julie Portman, Shekhar Regmi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Indoor air pollutant concentrations can be influenced by how rapidly species are transported to and from surfaces. Consequently, a greater understanding of indoor transport phenomena to surfaces improves estimates of human exposure to indoor air pollutants. Here, we introduce two methods of rapidly and directly measuring species fluxes at indoor surfaces, allowing us to evaluate the transport-limited deposition velocity, v_t (a mass-transfer coefficient). The deposition velocity sensor (DeVS) method employs a small microbalance coated with a pure hydrocarbon, preferably octadecane. We quantify flux (or evaporation rate) of the hydrocarbon into a room by observing the rate of mass loss …

Design And Evaluation Of A Pdf Print Estimating System, Mengtsung Tai

Dissertations and Theses @ UNI

This research consisted of designing and evaluating portable document format (PDF) print estimating system to commercial systems. Taking into account functionality, reliability, standardization, and integration, the conventional design method (Pressman, 1997) was used to develop the print estimating system. Considering the printer's viewpoint, added features make the system function online and offline and compatible with all common computer platforms. After the system was developed, experts and entry-level users evaluated the system for software usability (Nielsen, 2000; Shneiderman, 1998). A total of 26 experts and 38 entry-level users responded to 14 questions about usability in a personal interview survey. Statistical analysis …