Numerical Analysis and Scientific Computing Commons^™

Export Database Derivation Approach For Supporting Object-Oriented Wrapper Queries, Ee Peng Lim, Hon-Kuan Lee

Research Collection School Of Computing and Information Systems

Wrappers export the schema and data of existing heterogeneous databases and support queries on them. In the context of cooperative information systems, we present a flexible approach to specify the derivation of object-oriented (OO) export databases from local relational databases. Our export database derivation consists of a set of extent derivation structures (EDS) which defines the extent and deep extent of export classes. Having well-defined semantics, the EDS can be readily used in transforming wrapper queries to local queries. Based on the EDS, we developed a wrapper query evaluation strategy which handles OO queries on the export databases. The strategy …

Images 2.1 : An Integrated Model Of An Arid Grazing System, Z G. Yan, K M. Wang

Resource management technical reports

The name IMAGES stands for An Integrated Model of an Arid Grazing Ecological System. The model was initiated by Dr R. Hacker in 1987-8 as an activity to (1) evaluate alternative management strategies and (2) identify key ecological processes and research priorities in shrub rangelands of Western Australia. Version 1 of the model was published in Agriculture Systems in 1991 (Hacker et al. 1991) and here after will be referred to as IMAGES 1. IMAGES 1 is a vegetation model, capable of predicting the prob ility of recruitment and mortality of the desirable species in a given vegetation type under …

An Evidential Reasoning Approach To Attribute Value Conflict Resolution In Database Integration, Ee Peng Lim, Jaideep Srivastava, Shashi Shekhar

Research Collection School Of Computing and Information Systems

Resolving domain incompatibility among independently developed databases often involves uncertain information. DeMichiel [1] showed that uncertain information can be generated by the mapping of conflicting attributes to a common domain, based on some domain knowledge. In this paper, we show that uncertain information can also arise when the database integration process requires information not directly represented in the component databases, but can be obtained through some summary of data. We therefore propose an extended relational model based on Dempster-Shafer theory of evidence [2] to incorporate such uncertain knowledge about the source databases. The extended relation uses evidence sets to represent …

Monte Carlo Simulations Of Photoemission Characteristics From Gaas And Diamond, Abhishek Srivastava

Electrical & Computer Engineering Theses & Dissertations

Monte Carlo based numerical simulations were performed to study photoemission from GaAs and diamond. The central goal was to assess the potential for NEA photoemission from diamond, and to predict its characteristics. The GaAs material system was also included in the simulation study to provide: (i) calibration and validation of the numerical model developed by carefully matching the simulation results with available experimental data, and (ii) quantitative comparisons between the response characteristics of diamond and the better known GaAs system.

Predictions of the energy distribution, temporal response and angular distribution of emitted electrons were obtained. Effects of various parameters, such …

A New Soft Tissue Analysis : To Establish Facial Esthetic Norms In Young Adult Females, Anne Béress

Loma Linda University Electronic Theses, Dissertations & Projects

Two hundred and fifty-five articles, books, and masters theses were reviewed for the most frequently applied soft tissue measurements in the literature in order to develop a new soft tissue analysis computer program that includes established soft tissue measurements and the newly developed globe analysis. A meta analysis of 20 normal occlusion studies, was performed to obtain mean values and standard deviations to form a large sample size. Inclusion criteria for articles in the meta analysis were normal occlusion, no orthodontic treatment, pleasing faces, statement on age, race, and lip position of the population. For the lateral view, angular and …

On Integrating Existing Bibliographic Databases And Structured Databases, Ying Lu, Ee Peng Lim

Research Collection School Of Computing and Information Systems

It is widely accepted that future digital library applications have to be built upon different kinds of database servers to draw different forms of data from them. These data include bibliographic data, text data, multimedia data, and structured data. We address the problem of integrating existing bibliographic and structured databases which reside at different locations in the network. To integrate bibliographic data and structured data, we extended the well-known SQL model to represent bibliographic related attributes and queries. In particular, we have added a new data type to model attributes in the bibliographic database. We have also designed specialized predicates …

Specifying Object-Oriented Federated Database From Existing Databases, Ee Peng Lim, M. L. Lim, J. Srivastava

Research Collection School Of Computing and Information Systems

In this paper, we present a mapping strategy that is based on a proposed set of DB integration operations. We first define an OO federated DB as a virtual view on multiple OO export DBs. Our DB mapping strategy systematically derives each of the class extents, deep class extents and relationships of the federated DB using an operator tree consisting of the integration operations. This mapping approach differs from the other existing approaches in that it is algebraic based, and is therefore very suitable for implementing federated query processing.

Supporting Search For Reusable Software Objects, T. Isakowitz, Robert J. Kauffman

Research Collection School Of Computing and Information Systems

Prior research has shown that achieving high levels of software reuse in the presence of repository and object-based computer-aided software engineering (CASE) development methods presents interesting human, managerial and technical challenges. This article presents research that seeks to enhanced software development performance through reuse. We propose automated support for developers who search large repositories for the appropriate reusable software objects. We characterize search for repository objects in terms of a multistage model involving screening, identification, and the subsequent choice between new object construction or reusable object implementation. We propose automated support tools, including ORCA, a software Object Reuse Classification Analyzer, …

Gnarly Rantings About The Hacker And The Ants, Rudy Rucker

SWITCH

The article is an excerpt from Rucker’s book “The Happy Mutant”. It begins with his reflection of his career with GoMotion. He discusses the relation that he saw between design and cyberspace. Later he discusses his experience with a game a colleague found on the net: a virtual world where player is an ant. He talks about the struggles he goes through in this virtual world because of game difficulty and poor visuals. He ties it all in with how the Silicon Valley works in a similar way, and is filled with hackers and programers all needing each other to …

How I Got Gnarly, Rudy Rucker

SWITCH

The article describes how Rudy Rucker’s curious interest in celluar automata led to his career in mathematical computer science at San José State University. After conducting interviews on the theory of cellular automata as a freelance writer, he felt compelled to be involved in this great intellectual revolution in computer-aided experimental mathematics. Committed to reinventing himself, Rucker's interactions with mathematicians inspired him to write “Mind Tools”, a book that surveys mathematics from the standpoint that is information. After publishing his book, in 1987, he was eventually offered a position at SJSU in the Mathematics and Computer Science department. With assistance …

Entity Identification In Database Integration, Ee Peng Lim, Jaideep Srivastava, Satya Prabhakar, James Richardson

Research Collection School Of Computing and Information Systems

The objective of entity identification is to determine the correspondence between objective instances from more than one database. This paper examines the problem at the instance level assuming that schema level heterogeneity has been resolved a priori. Soundness and completeness are defined as the desired properties of any entity-identification technique. To achieve soundness, a set of identity and distinctness rules have to be established for the entities in the integrated world. We then propose the use of extended key, which is the union of keys (and possibly other attributes) from the relations to be matched, and its corresponding identity rule …

Volunteer Water Quality Monitoring Programs: An Assessment Of Public Participation As A Means Of Fostering Environmental Stewardship, Christopher Damon

Marine Affairs Theses and Major Papers

Volunteer water quality monitoring organizations from across the country were surveyed (n=516) to determine the relationship between public involvement and the generation of stewardship within the community. Program coordinators were asked first to rate the level of stewardship values within the community, and then respond to questions covering four broad areas of public involvement: pre-existing conditions, public education, volunteer behavior, and communal involvement. For each question, organizations were aggregated by response, and a frequency analysis was performed to discover the most common responses in each of the four public involvement categories. the mean of perceived stewardship values was graphed as …

On The Complexity Of Manpower Shift Scheduling, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

We consider the shift assignment problem in manpower scheduling, and show that a restricted version of it is NP-hard by a reduction from 3SAT. We then present polynomial algorithms to solve special cases of the problem and show how they can be deployed to solve more complex versions of the shift assignment problem. Our work formally defines the computational intractibility of manpower shift scheduling and thus justifies existing works in developing manpower scheduling systems using combinatorial and heuristic techniques.

Parallel Newton-Krylov-Schwarz Solvers For The Full Potential Flow Equation, Jie Zhang

Computer Science Theses & Dissertations

Newton-Krylov-Schwarz methods are increasingly applied in Computational Fluid Dynamics (CFD). We develop a parallel analysis code based on this method for the full potential flow model. The full potential model consists of a single nonlinear second-order partial differential equation of mixed type (elliptic/hyperbolic), which we solve as a steady boundary-value problem.

We use a nine-point finite-difference stencil to discretize the equation. A Newtonlike linearization and correction method is used to solve the resulting set of nonlinear algebraic equations. To solve the inner linear equations, we employ a Krylov space method. Preconditioners are used to improve the convergence rate. In order …