Computer Sciences Commons^™

Module Embedding, Atanas Radenski

Mathematics, Physics, and Computer Science Faculty Articles and Research

This paper proposes a code reuse mechanism called module embedding that enables the building of new modules from existing ones through inheritance, overriding of procedures, and overriding of types; the paper also describes an implementation scheme for this mechanism. Module embedding is beneficial when modules and classes are used in combination and need to be extended together, or when modules are more appropriate medium than classes.

Ta Da! - The Text Adventure Design Assistant A Visual Tool For The Development Of Adventure Games, Sean Molley

Masters Theses & Specialist Projects

In this paper, I survey past and present tools available to text adventure game authors, and then describe a new product: the Text Adventure Design Assistant (TA DA!), a visual programming system for creating text adventure games. My system consists of two parts: an abstract framework which defines an archetypical game, and a user interface which allows for the construction of games in a visual manner by manipulating the elements of the abstract game to produce a concrete design. The two most popular contemporary programming languages for creating text adventure games, TADS and Inform, are compared and contrasted, and my …

Velocity Estimation Via A Neural Network Enhanced By Classical Detection Algorithms, Zeki Berk Hamşioğlu

Electrical & Computer Engineering Theses & Dissertations

The goal of this research is to show how to solve a velocity estimation problem using a neural network connected to an array of sensors. Motivated by biological studies involving insect vision, the neural network utilized is a member of a class of shunting neural networks. When an object moves across the face of the sensor array, the neural network's pulse response is first temporally located using classical M-ary detection techniques. Both the deterministic and stochastic cases are considered. Then the network's pulse response is post-processed via an existing velocity estimation algorithm based on a Volterra series model of the …

Search For Sleptons In E+E- Collisions At Centre-Of-Mass Energies Of 161 Gev And 172 Gev, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

The data recorded by the ALEPH experiment at LEP at centre–of–mass energies of 161 GeV and 172 GeV were analysed to search for sleptons, the supersymmetric partners of leptons. No evidence for the production of these particles was found. The number of candidates observed is consistent with the background expected from four–fermion processes and γγ–interactions. Improved mass limits at 95% C.L. are reported.

Measurement Of The Transverse Spin Correlations In The Decay Z → Τ+Τ-, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

A measurement of the transverse-transverse, CTT, and transverse-normal CTN, τ spin correlations in the decay Z0 → τ+ τ− is presented based on the aplanarity angle of the decay products of both taus. Based on 80 pb−1 of data collected by ALEPH[1] in 1992, 1993 and 1994 on the peak of the Z resonance, the results are: CTT = 1.00 ± 0.14(stat) ± 0.04(syst), CTN =−0.08 ± 0.14(stat) ± 0.02(syst). These values are in agreement with the Standard Model predictions, CTT = 0.989 and CTN = 0.

Technologies For Ubiquitous Supercomputing: A Java Interface To The Nexus Communication System, Ian Foster, George K. Thiruvathukal, Steven Tuecke

Computer Science: Faculty Publications and Other Works

We use the term ubiquitous supercomputing to refer to systems that integrate low- and mid-range computing systems, advanced networks and remote high-end computers with the goal of enhancing the computational power accessible from local environments. Such systems promise to enable new applications in areas as diverse as smart instruments and collaborative environments. However, they also demand tools for transporting code between computers and for establishing flexible, dynamic communication structures. In this article, we propose that these requirements be satisfied by introducing Java classes that implement the global pointer and remote service request mechanisms defined by a communication library called Nexus. …

Search For The Bc Meson In Hadronic Z Decays, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

A search for the Bc meson decaying into the channels Jψπ+ and Jψℓ+νℓ (ℓ = e or μ) is performed in a sample of 3.9 million hadronic Z decays collected by the ALEPH detector. This search results in the observation of 0 and 2 candidates in each of these channels, respectively, while 0.44 and 0.81 background events are expected. The following 90% confidence level upper limits are derived:Br(Z→BcXBr(Z→qq̄Br(Bc+→Jψπ+)

Designing A High-Quality Network: An Application-Oriented Approach, Sudheer Dharanikota

Computer Science Theses & Dissertations

As new computer network technologies emerge, the application designers and the application users expect an increasing level of quality of service from them. Hence, it is a common practice in the newer technologies to provide more Quality of Service (QoS) components. Until now, these QoS solutions have been both network-technology specific and network-oriented solutions. In this thesis, we present an application-oriented approach to design a high quality network which is independent of the underlying communication technology. In this thesis, we propose a QoS architecture to "provide predictable performance to the end-to-end application users in a high quality networking environment." In …

A System For Query Comprehension, Hock Chuan Chan, Kwok Kee Wei, Keng Siau

Research Collection School Of Computing and Information Systems

A major difficulty of query writing is that users do not fully understand queries. A system providing feedback is proposed so as to enable users to better understand their queries. It is a multi-functional rule-based system. In addition to providing an English translation for the query, it pin-points syntax errors, and suggests possible solutions. It also finds likely semantic errors, and provides possible solutions. The system was implemented for a query language based on the entity relationship model. It is expected to lead to better user performance. Empirical testing showed significant improvement in user performance with the feedback system. The …

Experiments With "Hp Java", Bryan Carpenter, Yuh-Jye Chang, Geoffrey C. Fox, Donald Leskiw

Northeast Parallel Architecture Center

We consider the possible role of Java as a language for High Performance Computing. After discussing reasons why Java may be a natural candidate for a portable parallel programming language, we describe several case studies. These cover Java socket programming, message-passing through a Java interface to MPI, and class libraries for data-parallel programming in Java.

Microlanguages For Operating System Specialization, Calton Pu, Andrew P. Black, Crispin Cowan, Jonathan Walpole, Charles Consel

Computer Science Faculty Publications and Presentations

Specialization is a technique that has the potential to provide operating system clients with the performance and functionality that they need, while still retaining the advantages of a simple generic code base for the operating system maintainer. However, at present the specialization process is labor-intensive and requires the knowledge of an expert in the domain of application behavior. In order to realize the full advantages of specialization, we believe that the process must be automated. This means building tools for specialization, and also making the domain knowledge explicit in some form or other. A specialization toolkit has been developed jointly …

Four-Fermion Production In E+E- Collisions At Centre-Of-Mass Energies Of 130 And 136 Gev, D. Buskulic, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

Four-fermion events have been selected in a data sample of 5.8 pb−1 collected with the aleph detector at centre-of-mass energies of 130 and 136 GeV. The final states ℓ+ℓ−qq, ℓ+ℓ−ℓ+ℓ−, ννqq, and ννℓ+ℓ− have been examined. Five events are observed in the data, in agreement with the Standard Model predictions of 6.67±0.38 events from four-fermion processes and 0.14−0.05+0.19 from background processes.

A Computational Paradigm On Network-Based Models Of Computation, Venkatavasu Bokka

Computer Science Theses & Dissertations

The maturation of computer science has strengthened the need to consolidate isolated algorithms and techniques into general computational paradigms. The main goal of this dissertation is to provide a unifying framework which captures the essence of a number of problems in seemingly unrelated contexts in database design, pattern recognition, image processing, VLSI design, computer vision, and robot navigation. The main contribution of this work is to provide a computational paradigm which involves the unifying framework, referred to as the multiple Query problem, along with a generic solution to the Multiple Query problem.

To demonstrate the applicability of the paradigm, a …

Measurement Of The Mass Of The Λb Baryon, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

On The Interaction Of Object-Oriented Design Patterns And Programming Languages, Gerald Baumgartner, Konstantin Läufer, Vincent F. Russo

Computer Science: Faculty Publications and Other Works

Design patterns are distilled from many real systems to catalog common programming practice. However, some object-oriented design patterns are distorted or overly complicated because of the lack of supporting programming language constructs or mechanisms. For this paper, we have analyzed several published design patterns looking for idiomatic ways of working around constraints of the implementation language. From this analysis, we lay a groundwork of general-purpose language constructs and mechanisms that, if provided by a statically typed, object-oriented language, would better support the implementation of design patterns and, transitively, benefit the construction of many real systems. In particular, our catalog of …

Compiling Evaluable Functions In The GöDel Programming Language, David Shapiro

Dissertations and Theses

We present an extension of the Gödel logic programming language code generator which compiles user-defined functions. These functions may be used as arguments in predicate or goal clauses. They are defined in extended Gödel as rewrite rules. A translation scheme is introduced to convert function definitions into predicate clauses for compilation. This translation scheme and the compilation of functional arguments both employ leftmost-innermost narrowing. As function declarations are indistinguishable from constructor declarations, a function detection method is implemented.

The ultimate goal of this research is the implementation of extended Gödel using needed narrowing. The work presented here is …

Compile-Time Performance Prediction Of Hpf/Fortran 90d, Manish Parashar, Salim Hariri

Electrical Engineering and Computer Science - All Scholarship

In this paper we present an interpretive approach for accurate and cost-effective performance prediction in a high performance computing environment, and describe the design of a compile-time HPF/Fortran 90D performance prediction framework based on this approach. The performance prediction framework has been implemented as a part of the HPF/Fortran 90D application development environment that integrates it with a HPF/Fortran 90D compiler and a functional interpreter. The current implementation of the environment framework is targeted to the iPSC/860 hypercube multicomputer system. A set of benchmarking kernels and application codes have been used to validate the accuracy, utility, and usability of the …

Measurement Of The Λb Polarization In Z Decays, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

The Λb polarization in hadronic Z decays is measured in semileptonic decays from the average energies of the charged lepton and the neutrino. In a data sample of approximately 3 million hadronic Z decays collected by the ALEPH detector at LEP between 1991 and 1994, 462 ± 31 Λb candidates are selected using (Λπ+)-lepton correlations. From this event sample, the Λb polarization is measured to be PΛb = −0.23−0.20+0.24(stat.)−0.07+0.08(syst.).

Test Of The Flavour Independence Of Αs, D. Buskulic, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

Using about 950 000 hadronic events collected during 1991 and 1992 with the ALEPH detector, the ratios r b = bs=udsc s and r uds = uds s =cbs have been measured in order to test the avour independence of the strong coupling constant s . The analysis is based on event{shape variables using the full hadronic sample, two b-quark samples enriched by lepton tagging and lifetime tagging, and a light-quark sample enriched by lifetime antitagging. The combined results are r b = 1:002 0:023 and r uds = 0:971 0:023.

The Forward-Backward Asymmetry For Charm Quarks At The Z Pole, D. Buskulic, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

From 1.4 million hadronic Z decays collected by the ALEPH detector at LEP, an enriched sample of Z → cc̄ events is extracted by requiring the presence of a high momentum D∗±. The charm quark forward-backward charge asymmetry at the Z pole is measured to be AFB0.c = (8.0 ± 2.4) % corresponding to an effective electroweak mixing angle of sin2θWeff = 0.2302 ± 0.0054.

Search For Supersymmetric Particles With R-Parity Violation In Z Decays, D. Buskulic, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

Searches for supersymmetric particles produced in e+e− interactions at the Z peak have been performed under the assumptions that R-parity is not conserved, that the dominant R-parity violating coupling involves only leptonic fields, and that the lifetime of the lightest supersymmetric particle can be neglected. In a data sample collected by the ALEPH detector at LEP up to 1993, and corresponding to almost two million hadronic Z decays, no signal was observed. As a result, supersymmetric particle masses and couplings are at least as well constrained as under the usual assumption of R-parity conservation.

Michel Parameters And Τ Neutrino Helicity From Decay Correlations In Z → Τ+Τ-, D. Buskulic, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

Objects, Interference, And The Yoneda Embedding, Peter W. O'Hearn, Uday S. Reddy

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

We present a new semantics for Algol-like languages that combines methods from two prior lines of development: [1] the object-based approach of [28,29], where the meaning of an imperative program is described in terms of sequences of observable actions, and [2] the functor-category approach initiated by Reynolds [31], where the varying nature of the run-time stack is explained using functors from a category of store shapes to a category of cpos. The semantics gives an account of both the phenomena of local state and irreversibility of state change. As an indication of the accuracy obtained, we present a full abstraction …

Syntactic Control Of Interference Revisited, Peter W. O'Hearn, A. J. Power, M. Takeyama, R. D. Tennent

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

In "Syntactic Control of Interference" (POPL, 1978), J. C. Reynolds proposes three design principles intended to constrain the scope of imperative state effects in Algol-like languages. The resulting linguistic framework seems to be a very satisfactory way of combining functional and imperative concepts, having the desirable attributes of both purely functional languages (such as pcf) and simple imperative languages (such as the language of while programs). However, Reynolds points out that the "obvious" syntax for interference control has the unfortunate property that fi-reductions do not always preserve typings. Reynolds has subsequently presented a solution to this problem (ICALP, 1989), but …

Parametricity And Local Variables, Peter W. O'Hearn, R. D. Tennent

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

We propose that the phenomenon of local state may be understood in terms of Strachey 's concept of parametric (i.e., uniform) polymorphism. The intuitive basis for our proposal is the following analogy: a non-local procedure is independent of locally-declared variables in the same way that a parametrically polymorphic function is independent of types to which it is instantiated. A connection between parametricity and representational abstraction was first suggested by J. C. Reynolds. Reynolds used logical relations to formalize this connection in languages with type variables and user-defined types. We use relational parametricity to construct a model for an Algol-like language …

Note On Algol And Conservatively Extending Functional Programming, Peter W. O'Hearn

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

A simple Idealized Algol is considered, based on Reynolds's "essence of Algol." It is shown that observational equivalence in this language conservatively extends observational equivalence in its assignment-free functional sublanguage.

Exploiting High Performance Fortran For Computational Fluid Dynamics, Volume 919, Ken Hawick, Geoffrey C. Fox

Northeast Parallel Architecture Center

We discuss the High Performance Fortran data parallel programming language as an aid to software engineering and as a tool for exploiting High Performance Computing systems for computational uid dynamics applications. We discuss the use of intrinsic functions, data distribution directives and explicitly parallel constructs to optimize performance by minimizing communications requirements in a portable manner. In particular we use an implicit method such as the ADI algorithm to illustrate the major issues. We focus on regular mesh problems, since these can be efficiently represented by the existing HPF definition, but also discuss issues arising from the use of irregular …

An Ada-Like Language To Facilitate Reliable Coding Of Low Cost Embedded Systems, Michael Collins

Theses : Honours

Due to a lack of operating system (0/S) support, it is more difficult to develop programs for embedded systems than for workstations. For those developing on a low budget, the problem is often further compounded by the necessity of using inappropriate, 0/S dependent, compilers. This study attempts to ascertain those elements of a High Level Language (HLL) which are absolutely necessary and implementable to produce reliable, efficient, embedded programs without the benefit of a large budget. The study is based upon the Ada philosophy as the Ada language incorporates many desirable features for modelling real-world problems in terms of embedded …

Implementation And Evaluation Of Enhanced Areal Interpolation Using Mapinfo And Mapbasic, Gordon Wragg

Theses : Honours

Many researchers today have a need to analyse data in a spatial context. An inherent problem is the mismatch of boundaries between the geographic regions for which data is collected and those regions for which the data is required. Often the solution is to interpolate data from one set of regions to another. This project examines and implements a method of areal interpolation that enables the user to use extra information in areal interpolation to increase the "intelligence ' of the process. This method of Enhanced Areal Interpolation uses a conditional Poisson distribution and the EM algorithm to provide estimated …

First Measurement Of The Quark-To-Photon Fragmentation Function, D. Buskulic, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

Earlier measurements at LEP of isolated hard photons in hadronic Z decays, attributed to radiation from primary quark pairs, have been extended in the ALEPH experiment to include hard photon production inside hadron jets. Events are selected where all particles combine democratically to form hadron jets, one of which contains a photon with a fractional energy z 0:7. After statistical subtraction of non-prompt photons, the quark-to-photon fragmentation function, D(z), is extracted directly from the measured 2-jet rate. By taking into account the perturbative contributions to D(z) obtained from an O(S ) QCD calculation, the unknown non-perturbative component of D(z) is …