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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

An intelligent assistant to re-configure parameter-driven systems

Poon, Josiah Chun-Fai, josiah.poon@deakin.edu.au January 1994 (has links)
Parameter-Driven Systems (PDS) are widely used in commerce for large-scale applications. Reusability is achieved with a PDS design by relocating implicit control structures in the software and the storage of explicit data in database files. This approach can accommodate various user requirements without tedious modification of the software. In order to specify appropriate parameters in a system, knowledge of both business activities and system behaviour are required. For large, complex software packages, this task becomes time consuming and requires specialist knowledge, yet the consistency and correctness still cannot be guaranteed. My research studied the types of knowledge required and agents involved in the PDS customisation. The work also identified the associated problems and constraints. A solution is proposed and implemented as an Intelligent Assistant prototype than a manual approach. Three areas of achievement have been highlighted: 1. The characteristics and problems of maintaining parameter instances in a PDS are defined. It is found that the verification is not complete with the technical/structural knowledge alone, but a context is necessary to provide semantic information and related business activities (thus the implemented parameters) so that mainline functions can relate with each other. 2. A knowledge-based modelling approach has been proposed and demonstrated via a practical implementation. A Specification Language was designed which can model various types of knowledge in a PDS and encapsulate relationships. The Knowledge-Based System (KBS) developed verifies parameters based on the interpreted model of a given context. 3. The performance of the Intelligent Assistant prototype was well received by the domain specialist from the participating organisation. The modelling and KBS approach developed in my research offers considerable promise in solving practical problems in the software industry.
22

Experimental investigation on evaporation induced convection in water using laser based measurement techniques

Song, Xudong 11 1900 (has links)
Recent studies showed that evaporation of water can induce surface tension gradients along the water surface and ultimately lead to convection, known as Marangoni convection. This study was devoted to visualization and characterization of the evaporation-induced, surface-tension-driven convection in water using laser-based measurement techniques. The evaporation of water at various low vapor-phase pressures in the absence of buoyancy driven flow was investigated. Strong symmetric convection was observed and its velocity field was measured using stereo particle image velocimetry. The temperature field obtained from using both a thermocouple and planar laser induced fluorescence indicated that no buoyancy driven flow was generated. The strength of the convection was found to be correlated with the evaporation rate of water. In addition, the estimated Marangoni number exceeded the critical value for onset of Marangoni convection. It can be concluded that the observed evaporative convection of water can only be Marangoni convection.
23

Smart Modeling of Drilling-Well in an Integrated Approach

Rahman, Shah Md Rajiur 06 1900 (has links)
The current well planning practice is usually done section by section with limited help of some knowledge-based tools. This thesis presents an integrated approach and a software prototype developed for well planning. It considers the geological input, i.e. pore pressure, over burden etc., to generate a step by step interactive drilling plan. The implemented well planning stages include the casing setting depth, casing and hole size determination, casing selection and then drill string design and modeling. The system is integrated with a Computer Aided Design (CAD) system for generating three-dimensional parametric model. The conceptual design and CAD modeling system are integrated in such a way that any changes in the design will be reflected to the CAD model. Such intelligent CAD design practice is new in the drilling industry. An Operational Parameters module is also attached with the system to predict the drilling coefficients by using offset well data and determine the optimum weight on bit, and the drill string rotation that minimizes drilling cost per foot for a single bit run. Based on this approach, an integrated well planning system can be fully developed and it will be very useful for the decision making of drilling companies.
24

Data-driven human body morphing

Zhang, Xiao 01 November 2005 (has links)
This thesis presents an efficient and biologically informed 3D human body morphing technique through data-driven alteration of standardized 3D models. The anthropometric data is derived from a large empirical database and processed using principal component analysis (PCA). Although techniques using PCA are relatively commonplace in computer graphics, they are mainly used for scientific visualizations and animation. Here we focus on uncovering the underlying mathematical structure of anthropometric data and using it to build an intuitive interface that allows the interactive manipulation of body shape within the normal range of human variation. We achieve weight/gender based body morphing by using PCA. First we calculate the principal vector space of the original data. The data then are transformed into a new orthogonal multidimensional space. Next, we reduce the dimension of the data by only keeping the components of the most significant principal vectors. We then fit a curve through the original data points and are able to generate a new human body shape by inversely transforming the data from principal vector space back to the original measuring data space. Finally, we sort the original data by the body weight, calculating males and females separately. This enables us to use weight and gender as two intuitive controls for body morphing. The Deformer program is implemented using the programming language C++ with OPENGL and FLTK API. 3D and human body models are created using Alias MayaTm.
25

ESL Model of the Hyper-scalar Processor on a Chip

Chen, Po-kai 20 August 2007 (has links)
This paper proposed a scalable chip multiprocessor architecture, which is called Hyper-scalar combined with the concept of superscalar and multithreaded architecture; hence, this architecture can enhance single-threaded performance by using core group and also supports multithreaded applications. System programmer can dynamically allocate the core groups to accelerate a single thread by extended system instructions. In order to solve the data dependence between all issued instructions the virtual shared register file is proposed. This mechanism allows the data in local register files to be accessed from other cores through the data switching path hardware and the instructions are executed only when the operands are available. The instructions within a single-threaded application can be dispatched to variable cores without re-compilation. This execution paradigm accelerates the single-threaded performance more flexibly. In the case of simulation and experimental framework, the ESL Model written in SystemC, a modeling language based on C++ is to provide hardware-oriented simulation platform and the MediaBench suite is selected for the experiments. On average, the Hyper-scalar architecture can accelerate single-threaded performance by 30% to 110% using 2 ~ 8 cores.
26

Table Driven Algorithm for Joint Sparse Form

Chen, Bing-hong 25 August 2007 (has links)
In Cryptography, computing a^xb^y mod n is the most important and the most time-consuming calculation The problem can be solved by classical binary method. Later research is based on this basis to increase computational efficiency. Furthermore, Binary signed-digit representation recoding algorithm, the Sparse Form, the DJM recoding method, and the Joint Sparse Form can be used to decrease the number of multiplication by aligning more non-zero bits. Another method is to pre-compute and store the part of the results to decrease the number of computations by shifting bits. Joint Sparse Form recording method is not a table driven algorithm in converting source codes into joint sparse form. In this paper, we first proposed a table driven algorithm for joint sparse form to simply recording concept. This algorithm can be constructed a finite state machine to denote the recording procedure. According to this finite state machine, we show that the average joint Hamming weight among joint sparse form is 0.5n when n approaches infinity. Finally, we show that the average joint Hamming weights of SS1 method and DS1 method among joint sparse form are 0.469n and 0.438n by using a similar method, respectively.
27

A UML Extension for the Model-driven Specification of Audit Rules

Hoisl, Bernhard, Strembeck, Mark January 2012 (has links) (PDF)
In recent years, a number of laws and regulations (such as the Basel II accord or SOX) demand that organizations record certain activities or decisions to fulfill legally enforced reporting duties. Most of these regulations have a direct impact on the information systems that support an organization's business processes. Therefore, the definition of audit requirements at the modeling-level is an important prerequisite for the thorough implementation and enforcement of corresponding policies in a software system. In this paper, we present a UML extension for the specification of audit properties. The extension is generic and can be applied to a wide variety of UML elements. In a model-driven development (MDD) approach, our extension can be used to generate corresponding audit rules via model transformations. (author's abstract)
28

Parameterized Code Generation From Template Semantics

Prout, Adam January 2006 (has links)
We have developed a tool that can create a Java code generator for a behavioural modelling notation given only a description of the notation's semantics as a set of parameters. This description is based on template semantics, which has previously been used to describe a wide variety of notations. As a result, we have a technique for generating Java code for models written in any notation describable in template semantics. Since template semantics allows for models containing nondeterminism, we introduce mechanisms for eliminating this nondeterminism when generating code. We describe Java implementations of several template-semantics composition operators that have no natural Java representations and give some techniques for optimizing the generated code without sacrificing correctness. The efficiency of our generated code is comparable to that of commercial notation-specific code generators.
29

Parameterized Code Generation From Template Semantics

Prout, Adam January 2006 (has links)
We have developed a tool that can create a Java code generator for a behavioural modelling notation given only a description of the notation's semantics as a set of parameters. This description is based on template semantics, which has previously been used to describe a wide variety of notations. As a result, we have a technique for generating Java code for models written in any notation describable in template semantics. Since template semantics allows for models containing nondeterminism, we introduce mechanisms for eliminating this nondeterminism when generating code. We describe Java implementations of several template-semantics composition operators that have no natural Java representations and give some techniques for optimizing the generated code without sacrificing correctness. The efficiency of our generated code is comparable to that of commercial notation-specific code generators.
30

Data-driven human body morphing

Zhang, Xiao 01 November 2005 (has links)
This thesis presents an efficient and biologically informed 3D human body morphing technique through data-driven alteration of standardized 3D models. The anthropometric data is derived from a large empirical database and processed using principal component analysis (PCA). Although techniques using PCA are relatively commonplace in computer graphics, they are mainly used for scientific visualizations and animation. Here we focus on uncovering the underlying mathematical structure of anthropometric data and using it to build an intuitive interface that allows the interactive manipulation of body shape within the normal range of human variation. We achieve weight/gender based body morphing by using PCA. First we calculate the principal vector space of the original data. The data then are transformed into a new orthogonal multidimensional space. Next, we reduce the dimension of the data by only keeping the components of the most significant principal vectors. We then fit a curve through the original data points and are able to generate a new human body shape by inversely transforming the data from principal vector space back to the original measuring data space. Finally, we sort the original data by the body weight, calculating males and females separately. This enables us to use weight and gender as two intuitive controls for body morphing. The Deformer program is implemented using the programming language C++ with OPENGL and FLTK API. 3D and human body models are created using Alias MayaTm.

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