Physical Sciences and Mathematics Commons^™

Specification-Driven Optimization, Sheena Day

Dissertations and Theses

Traditionally, optimizing transformations have been built into compilers. The end-user has little or no control over guiding any optimizations that may be applied by the compiler. Moreover, the compiler-writer does not have a simple way to direct the optimizations. Thus, many potentially beneficial opportunities for code optimization may be lost. We have built a system that allows the user to participate in guiding source-to-source transformations via the specification of rewrite rules. A clean separation of the rules from the strategy of applying them makes the system easier to use and modify, compared to other integrated systems. This is especially relevant …

Studies Of Quantum Chromodynamics With The Aleph Detector, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

Measurement Of The Fraction Of Hadronic Z Decays Into Charm Quark Pairs, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

The full statistics of hadronic Z decays collected with the ALEPH detector are analysed to measure, by three methods, the ratio, RcRc, of the partial decay width of the Z into cc¯cc¯ quarks to the total hadronic width. One method uses the inclusive pp and p⊥p⊥ spectra of electrons. The other two use a double-tagging technique to measure RcRc independently of the charm-tagging efficiency. In one, the tagging procedure uses the reconstruction of high momentum charmed mesons (D∗+D∗+, D+D+ and \({\rm D^0}$) to detect the charm quarks. In the other, a charm quark is tagged from the D∗D∗'s reconstructed in …

Searches For Charginos And Neutralinos In E+E- Collisions At √S = 161 And 172 Gev, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

The data recorded by the ALEPH detector at centre-of-mass energies of 161, 170, and 172 GeV are analysed for signals of chargino and neutralino production. No evidence of a signal is found, although candidate events consistent with the expectations from Standard Model processes are observed. Limits at 95% C.L. on the production cross sections are derived and bounds on the parameters of the Minimal Supersymmetric Standard Model are set. The lower limit on the mass of the lightest ch is 85.5 GeV/c2GeV/c2 for gaugino-like charginos (μ=−500GeV/c2μ=−500GeV/c2), and 85.0 GeV/c2GeV/c2 for Higgsino-like charginos (M2=500GeV/c2M2=500GeV/c2), for heavy sneutrinos (Mν~≥200GeV/c2Mν~≥200GeV/c2) and tanβ=2–√tan⁡β=2. The …

Measurement Of The Axial-Vector Τ Spectral Functions And Determination Of Αs (M2Τ) From Hadronic Τ Decays, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

An analysis based on 124 000 selected ττ pairs recorded by the ALEPH detector at LEP provides the vector (V)(V) and axial-vector (A)(A) spectral functions of hadronic ττ decays together with their total widths. This allows the evaluation of finite energy chiral sum rules that are weighted integrals over the (V−A)(V−A) spectral functions. In addition, a precise measurement of αsαs along with a determination of nonperturbative contributions at the ττ mass scale is performed. The experimentally and theoretically most robust determination of αs(M2τ)αs(Mτ2) is obtained from the (V+A)(V+A) fit that yields αs(M2τ)=0.334±0.022αs(Mτ2)=0.334±0.022 giving αs(M2Z)=0.1202±0.0027αs(MZ2)=0.1202±0.0027 after the extrapolation to the mass …

Search For Evidence Of Compositeness At Lep I, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

Extensive searches for evidence of compositeness of quarks and leptons have been made in the complete set of ALEPH data from LEP running at the Z peak. These include searches for radiative and weak decays of excited fermions, produced either in pairs or singly, and a scalar partner of the Z. Coupling and branching ratio limits deduced from these searches are presented.

Search For Supersymmetry With A Dominant R-Parity Violating Llē Coupling In E+E- Collisions At Centre-Of-Mass Energies Of 130 Gev To 172 Gev, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

A search for pair-production of supersymmetric particles under the assumption that R-parity is violated via a dominant LLE¯LLE¯ coupling has been performed using the data collected by ALEPH at centre-of-mass energies of 130–172 GeV. The observed candidate events in the data are in agreement with the Standard Model expectation. This is translated into lower limits on the mass of charginos, neutralinos, sleptons, sneutrinos and squarks. For instance, charginos with masses less than 73 GeV/c2c2 and neutralinos with masses less than 23 GeV/c2c2 are excluded at 95% confidence level for any generation structure of the LLE¯LLE¯ coupling, and for neutralino, slepton …

Study Of B0s Oscillations And Lifetime Using Fully Reconstructed D̄S Decays, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

A search for B0sBs0 oscillations is performed using approximately 4 million Z→qq¯Z→qq¯ events collected by the ALEPH experiment during 1991–1995. B0sBs0 candidates are partially reconstructed by combining tracks with fully reconstructed D−sDs− candidates. The B0sBs0 production flavour is estimated from the sign of the opposite hemisphere charge, a fragmentation kaon in the same hemisphere, or a lepton in the opposite hemisphere. From a total sample of 1620 candidates, with a B0sBs0 purity estimated to be 22%, all values of ΔmsΔms below 3.9 ps−1−1 and between 6.5 and 8.8 ps−1−1 are excluded at 95% CL. From the same sample, the B0sBs0 …

An Interlibrary Loan System On The World Wide Web, Schubert Shou Boon Foo, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Inter-Library Loan (ILL) service is one of the services provided by libraries that offers users a way to access library resources beyond their affiliated libraries. Additionally, it allows participating libraries to share and maximize their resources. This work examines the ILL process used by libraries in Singapore and proposes that the existing paper-based manual system be replaced by a Web-based ILL system. Such a Web-based system has been successfully designed and implemented at the Nanyang Technological University. The paper presents an overview of the system requirements and architecture, implementation details and demonstrates the feasibility and advantages of the new system.

A Java Implementation Of A Portable Desktop Manager, Scott J. Griswold

UNF Graduate Theses and Dissertations

Computers equipped with a Graphical User Interface (GUI) and connected to the Internet are common in both the business and educational communities. These computers, using a web browser, easily share programs written in the Java programming language that are able to execute on a variety of heterogeneous machines.

While programs written in many languages will not execute unmodified on different computing platforms because of portability restrictions, Java has overcome these limitations and provides a platform independent language. However, every programming language is limited, and no language provides all the features required for every program. Therefore, creation of any portable program …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 14, Number 1, January 1998, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A fourteen page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

An Integrated Web-Based Ill System For Singapore Libraries, Schubert Foo, Ee Peng Lim

Research Collection School Of Computing and Information Systems

The paper proposes an integrated Web-based inter-library loan (ILL) system to replace and enhance the existing manual-based ILL system used by Singapore libraries. It describes the system requirements that must be supported in order to make it a viable and acceptable solution to all participating libraries. Subsequently, it presents the client-server Web-based system architecture, database design and Java development platform that are used to implement the system. The new system exhibits a host of advantages over the manual system including the minimising of human resource by eliminating form-filling and other forms of paper work completely, improving the access and speed …

The Adjoint Alternative For Matrix Operators, C. H. Cooke

Mathematics & Statistics Faculty Publications

The following inverse problem is considered: given a matrix B of rank r, does there exist a matrix A such that

B = T(A) = adjoint (A)

where the classical adjoint operation is intended? Conditions are determined on the rank of B which decides whether or not B lies in the range of the matrix adjoint operator.

Requirement Elicitation For Environmental Life Cycle Processes, Mariam Y. Burmawalla

Theses

To develop a user-satisfying product the most essential ingredient is to understand user's needs and expectations from the system. Lack of communication between the user and the developer results in an unsatifying output from the user's point of view. Thus proper understanding between the stakeholder and the developer is the most important requirement during the development of any system.

Requirement elicitation process is one such means of expressing wants and requirements from the system by both the parties. Based on Software Engineering Institute's model, requirement elicitation is a web-based application that allows all the people involved in the system to …

Parametric Software Project Estimating: An Analysis Of Current Practice, Stuart Hope

Theses: Doctorates and Masters

As society and the world economy moves into the second millennium. the service industries involving knowledge workers will continue to increase. Software is the enabling technology that is driving the knowledge industry. As the development of software is mostly a design process, where new artefacts are conceived and built, the prediction of outcomes in the process is fraught with difficulties. Software project estimating is one of the essential Software Engineering techniques that will enable the rationalisation of decision-making regarding software development. Estimates that are more accurate will increase the probability of success and lower the risk. This thesis analyses the …

Using Multimedia Microworlds To Motivate And Engage Adult Learners, Susan B. Stoney

Theses: Doctorates and Masters

As educational institutions come under increasing pressure from outside forces to restructure the way students learn, efforts are being made by researchers to find ways to assist students to learn through independent thought and to solve problems in a resource-based, self-paced environment. Such an environment needs to be sufficiently interesting and novel to motivate students who begin to use it, and to continue to engage them as they progress through it. This study has sought to identify what such a learning environment needs to encompass in order to motivate and engage adult learners so that they will not only want …

Usability Of Visual Basic For Parallel Programming On Windows Nt, James Scott Barker

Dissertations and Theses

Visual Basic is a very popular language. Many hardware engineers have learned Visual Basic because of its simplicity, but have never learned C or C++. Furthermore, people are choosing not to use C or C++ for business software development, but instead are embracing languages such as Visual Basic. Since one of the goals of the parallel programming community has been to encourage more widespread use of parallelism in software, this body of programming talent needs to be addressed. This thesis intends to prove that Visual Basic can be used for parallel programming, that using it is at least as easy …

A Methodology For The Selection Of A Paradigm Of Reasoning Under Uncertainty In Expert System Development, Vivian Campbell

Theses: Doctorates and Masters

The aim of this thesis is to develop a methodology for the selection of a paradigm of reasoning under uncertainty for the expert system developer. This is important since practical information on how to select a paradigm of reasoning under uncertainty is not generally available. The thesis explores the role of uncertainty in an expert system and considers the process of reasoning under uncertainty. The possible sources of uncertainty are investigated and prove to be crucial to some aspects of the methodology. A variety of Uncertainty Management Techniques (UMTs) are considered, including numeric, symbolic and hybrid methods. Considerably more information …

Automatic Flowchart Displays For Software Visualisation, Paul R. Schurmann

Theses: Doctorates and Masters

Understanding large software projects and maintaining them can be a time consuming process. For instance, when changes are made to source code, corresponding changes have to be made to any related documentation. One large section of the documentation process is the creation and management of diagrams. Currently there are very few automated diagramming systems that can produce diagrams from source code, and the majority of these diagramming systems require a significant amount of time to generate diagrams. This research aims at investigating the process of creating flowchart diagrams from source code and how this process can be fully automated. Automating …

User Response And Organisational Fit For Information Systems In Earth Observation, Jeff Kingwell

Theses: Doctorates and Masters

A group of seventy six scientists and data managers in the Australian research agency CSIRO were surveyed to establish their needs and preferences in relation to information systems for Earth observation data. After study of available alternatives, three prototype Earth observation information management systems were installed and the user response was evaluated through interview of fifteen of the group. The prototypes consisted of web-based client servers which permitted users to interrogate databases of Earth observation datasets; to search for information about sensor or satellite performance, and to retrieve data and information products. The chosen systems were CILS, the CEOS (Committee …

The Auditory Display In Interactive Courseware: Moving Human Factors Into Computer Education, David T. Lauret

CCE Theses and Dissertations

The arrival of inexpensive high fidelity audio capabilities for personal computers has been accompanied by sweeping claims of enhanced educational effectiveness. Research has only served to confuse these claims with both significant and non-significant findings. This may be due partly to the single dimensional model which has been assumed when examining audio. When computer-based audio is examined as a multi-dimensional display analogous in capability and function to the more familiar visual display (computer screen), a different picture emerges. Although it is now clear that integrated audio can enhance learning, the instructional designer is still left with little guidance whether or …

An Interoperability Infrastructure For Developing Multidatabase Systems, Asuman Doğac, Gökhan Özhan, Ebru Kılıç, Fatma Özcan, Sena Nural, Sema Mancuhan, Cevdet Dengi, Pınar Köksal, Uğur Halıcı, Budak Arpınar, Cem Evrendilek, Vahid Sadjadi

Turkish Journal of Electrical Engineering and Computer Sciences

A multidatabase system (MDBS) allows the users to simultaneously access autonomous, heterogeneous databases using a single data model and a query language. This provides for achieving interoperability among heterogeneous, federated DBMSs. In this paper, we describe the interoperability infrastructure of a multidatabase system, namely METU Interoperable DBMS (MIND). The architecture of MIND is based on OMG distributed object management model. It is implemented on top of a CORBA compliant ORB, namely, ObjectBroker. The interface of the generic database object is defined in CORBA IDL and multiple implementations of this interface, one for each component DBMSs, namely, Oracle 7, Sybase, Adabas …

Analysis Of Images Of Cells With Neurites, Florence Cloppet, Georges Stamon

Turkish Journal of Electrical Engineering and Computer Sciences

This study is concerned with the segmentation of cytological images and extraction of cellular entities in order to provide quantitative data about the number of cells in culture (statistical tests, morphology, model of evolution, etc). This quantitative supply is useful in biology to evaluate the consequences of the application of active substances on morphological changes and cellular viability. It is related to the conception of a system dedicated to automatic analysis of cell images, in order to evaluate the effects of drugs on the morphology of neuronal cells. We use a cooperative region / contour segmentation, which gives closed polygonal …

Signal Injection With Perceptual Criteria, T. Engi̇n Tuncer

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel method for increasing the coding performance and information transmission capacity is presented. This method is mainly based on perceptual modelling of input signal such as speech or audio. Presented approach may be seen as an alternative to transforms which dynamically change analysis window for better energy compaction. A perceptual model is established in order to obtain a global masking threshold in frequency below which sounds become inaudible. Certain criteria are developed for identifying the signal injection bands. A new multiband filter design method which is a generalization of windowing method is used to separate the …

Imaging Electrical Current Density Using Nuclear Magnetic Resonance, B. Murat Eyüpoğlu, Ravinder Reddy, John S. Leigh

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, images of nonuniform and uniform electric current density in conductor phantoms, which contain magnetic resonance active nuclei, are produced using Magnetic Resonance Imaging (MRI). A standard spin echo pulse sequence is used, with the addition of a bipolar current pulse. The flux density parallel to the main magnetic field, generated by the current pulse, is encoded in the phase of the complex MR image. The spatial distribution of magnetic flux density is extracted from the phase image. Current density is calculated using the magnetic flux density. This fairly recent technique is known as Magnetic Resonance Current Density …

Genetic Approach For The Determination Of Object Parameters From X Ray Projections, Tayfun Günel, Sedef Kent

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a new method is presented, based on genetic algorithms for determining object parameters such as radii and/or attenuation coefficients with some assumptions and estimating a cross-sectional image of an object from its projections obtained by X ray illumination. After it was tested for projections degraded by different random noise levels, it was observed that the genetic and fuzzy genetic algorithms improved the signal to noise ratio of the projections. The fuzzy genetic algorithm gave better results than the genetic algorithm.

Distribution System Planning Usign Mixed Integer Programming, Belgin Türkay

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an improved mathematical model to optimise the size and locations of substations and the network routing problem. The model was formulated to minimise the total cost of the network by determining the optima of the substation locations and power, the load transfers between the demand centers, the feeder routes and the load flow in the network subject to a set of constraints. The computational results of a devised sample problem indicate that the developed optimisation model and its code are adequate for computer aided planning of distribution systems.

Imaging Tissue Conductivity Via Contactless Measurements: A Feasibility Study, Nevzat G. Gençer, M. Nejat Tek

Turkish Journal of Electrical Engineering and Computer Sciences

The feasibility of a new imaging system is investigated. This system will be used to image electrical conductivity distribution of biological tissues via contactless measurements. This will be achieved by introducing currents in the conductive medium using time-varying magnetic fields and measuring the magnetic fields of the induced currents. Consequently, the imaging system consists of transmitter and receiver coils placed nearby the conductive body. In this study, the basic features of the coplanar and coaxial coils are studied. The validity of the simplifying assumptions for the governing field equations is investigated. It is found that, for operating frequency of 100 …

Reflective Remote Method Invocation, George K. Thiruvathukal, Lovely S. Thomas, Andy T. Korczynski

Computer Science: Faculty Publications and Other Works

Remote Method Invocation (RMI) is available in the current Java language design and implementation, providing the much-needed capability of allowing objects running in different Java processes to collaborate using a variation on the popular Remote Procedure Call (RPC).

Although RMI provides features which are desirable for high-performance distributed computing, its design and implementation are deficient in key areas of importance to the high-performance computing community in general. This paper addresses the key deficiencies of RMI and how these deficiencies affect the design and implementation of distributed object applications.

Reflective RMI (RRMI) is an open RMI implementation which makes better use …

Wide-Area Implementation Of The Message Passing Interface, Ian Foster, Jonathan Geisler, William Gropp, Nicholas Karonis, Ewing Lusk, George K. Thiruvathukal, Steven Tuecke

Computer Science: Faculty Publications and Other Works

The Message Passing Interface (MPI) can be used as a portable, high-performance programming model for wide-area computing systems. The wide-area environment introduces challenging problems for the MPI implementor, due to the heterogeneity of both the underlying physical infrastructure and the software environment at different sites. In this article, we describe an MPI implementation that incorporates solutions to these problems. This implementation has beenconstructed by extending the Argonne MPICH implementation of MPI to use communicationservices provided by the Nexus communication library and authentication, resource allocation, process creation/management, and information services provided by the I-Soft system (initially) and the Globus metacomputing toolkit …