Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 181 - 190 of 190

Full-Text Articles in Engineering

A Metaevaluation Of Energy Efficiency Evaluations, Brandy Brown Apr 2014

A Metaevaluation Of Energy Efficiency Evaluations, Brandy Brown

Dissertations

This study systematically reviews the methodological characteristics of energy efficiency evaluations and uses metaevaluation to assess its quality. Metaevaluation is used to systematically assess the quality of evaluation products, confirm that evaluations deliver sound findings and conclusions, are useful to the client, are credible, are ethically conducted, and are done as cost-effective as possible. The results of this study show that the ability to accurately assess evaluation for methodological quality using evaluations reports as a primary data source depends on the presence of detailed descriptions of evaluation methods. Furthermore, the study suggests that methodological variations of energy efficiency evaluations coalesce …


Synergy Of The Developed 6d Bim Framework And Conception Of The Nd Bim Framework And Nd Bim Process Ontology, Shawn Edward O'Keeffe Dec 2013

Synergy Of The Developed 6d Bim Framework And Conception Of The Nd Bim Framework And Nd Bim Process Ontology, Shawn Edward O'Keeffe

Dissertations

The author developed a unified nD framework and process ontology for Building Information Modeling (BIM). The research includes a framework developed for 6D BIM, nD BIM, and nD ontology that defines the domain and sub-domain constructs for future nD BIM dimensions. The nD ontology defines the relationships of kinds within any new proposed dimensional domain for BIM. The developed nD BIM framework and ontology takes into account the current 2D-5D BIM dimensions. There is a synergy between the 6D and nD framework that allows the nD framework and ontology to be utilized as a unified template for future dimensional development. …


Organic Solar Cells Based On High Dielectric Constant Materials: An Approach To Increase Efficiency, Khalil Jumah Tawfiq Hamam Jun 2013

Organic Solar Cells Based On High Dielectric Constant Materials: An Approach To Increase Efficiency, Khalil Jumah Tawfiq Hamam

Dissertations

The efficiency of organic solar cells still lags behind inorganic solar cells due to their low dielectric constant which results in a weakly screened columbic attraction between the photogenerated electron-hole system, therefore the probability of charge separating is low. Having an organic material with a high dielectric constant could be the solution to get separated charges or at least weakly bounded electron-hole pairs. Therefore, high dielectric constant materials have been investigated and studied by measuring modified metal-phthalocyanine (MePc) and polyaniline in pellets and thin films. The dielectric constant was investigated as a function of temperature and frequency in the range …


Compositional And Structural Analysis Of Nitrogen Incorporated And Ion Implanted Diamond Thin Films, Elias James Garratt Apr 2013

Compositional And Structural Analysis Of Nitrogen Incorporated And Ion Implanted Diamond Thin Films, Elias James Garratt

Dissertations

Significant progress in area of nano-structured thin film systems has taken place in recent decades. In particular, diamond thin film systems are being widely studied for their wear resistant, optical and electronic properties. Of the various methods researchers use to modify the structure of such films, three techniques in particular are of interest due to their versatility: modification of the growth atmosphere, growth on metalized substrates, providing an interfacial layer, and modification through post-growth ion implantation. The aim of this study is to investigate the effects each has to the structure and composition of elements. Different techniques are applied in …


Tropical Cyclone Intensity Estimation Using Temporal And Spatial Features From Satellite Data, Gholamreza Fetanat Haghighi Jan 2013

Tropical Cyclone Intensity Estimation Using Temporal And Spatial Features From Satellite Data, Gholamreza Fetanat Haghighi

Dissertations

Accurate intensity estimation of tropical cyclones (TC) is an important topic of research due to its economic impact and public safety concerns. An accurate measure of the current wind strength is necessary to accurately predict TC intensity. We have developed and tested automated method to estimate TC intensity based on the existing historical satellite images alone. The Hurricane Satellite data (HURSAT-B1) is used to develop the algorithm, which focuses on the North Atlantic from 1978-2009. The algorithm is trained and validated using aircraft reconnaissance-based data. Here, the data is restricted to include only fixes that are over water and are …


Adaptive Security-Aware Scheduling For Packet Switched Networks Using Real-Time Multi-Agent Systems, Ma'en Saleh Saleh Jun 2012

Adaptive Security-Aware Scheduling For Packet Switched Networks Using Real-Time Multi-Agent Systems, Ma'en Saleh Saleh

Dissertations

Conventional real-time scheduling algorithms are in care of timing constraints; they don’t pay any attention to enhance or optimize the real-time packet’s security performance. In this work, we propose an adaptive security-aware scheduling with congestion control mechanism for packet switching networks using real-time agentbased systems. The proposed system combines the functionality of real-time scheduling with the security service enhancement, where the real-time scheduling unit uses the differentiated-earliest-deadline-first (Diff-EDF) scheduler, while the security service enhancement scheme adopts a congestion control mechanism based on a resource estimation methodology.

The security service enhancement unit was designed based on two models: singlelayer and weighted …


Error Estimation Techniques To Refine Overlapping Aerial Image Mosaic Processes Via Detected Parameters, William Glenn Bond May 2012

Error Estimation Techniques To Refine Overlapping Aerial Image Mosaic Processes Via Detected Parameters, William Glenn Bond

Dissertations

In this paper, I propose to demonstrate a means of error estimation preprocessing in the assembly of overlapping aerial image mosaics. The mosaic program automatically assembles several hundred aerial images from a data set by aligning them, via image registration using a pattern search method, onto a GIS grid.

The method presented first locates the images from a data set that it predicts will not align well via the mosaic process, then it uses a correlation function, optimized by a modified Hooke and Jeeves algorithm, to provide a more optimal transformation function input to the mosaic program. Using this improved …


Leach-Sm: A Protocol For Extending Wireless Sensor Network Lifetime By Management Of Spare Nodes, Bilal Abu Bakr Jan 2011

Leach-Sm: A Protocol For Extending Wireless Sensor Network Lifetime By Management Of Spare Nodes, Bilal Abu Bakr

Dissertations

Operational lifetime of a wireless sensor network (WSN) depends on its energy resources. Significant improvement of WSN lifetime can be achieved by adding spare sensor nodes to WSN. Spares are ready to be switched on when any primary (a node that is not a spare) exhausts its energy. A spare replacing a primary becomes a primary itself.

The LEACH-SM protocol (Low-Energy Adaptive Clustering Hierarchy with Spare Management) proposed by us is a modification of the prominent LEACH protocol. LEACH extends WSN lifetime via rotation of cluster heads but allows for inefficiencies due to redundant sensing target coverage. There are two …


Cloud Computing:Strategies For Cloud Computing Adoption, Faith Shimba Sep 2010

Cloud Computing:Strategies For Cloud Computing Adoption, Faith Shimba

Dissertations

The advent of cloud computing in recent years has sparked an interest from different organisations, institutions and users to take advantage of web applications. This is a result of the new economic model for the Information Technology (IT) department that cloud computing promises. The model promises a shift from an organisation required to invest heavily for limited IT resources that are internally managed, to a model where the organisation can buy or rent resources that are managed by a cloud provider, and pay per use. Cloud computing also promises scalability of resources and on-demand availability of resources.

Although, the adoption …


Investigating Fabrication Methods For Micro Single-Chamber Solid Oxide Fuel Cells, Man Yang Jan 2010

Investigating Fabrication Methods For Micro Single-Chamber Solid Oxide Fuel Cells, Man Yang

Dissertations

A Solid Oxide Fuel Cell (SOFC) is a green energy technology that offers a cleaner and efficient alternative to fossil fuels. The efficiency and utility of SOFCs can be enhanced by fabricating miniaturized component structures within the fuel cell footprint. This research focuses on the microfabrication of parallel-connected inter-digitized design of micro single chamber SOFC (μ-SC-SOFCs). In this dissertation, candidate micro/nano fabrication techniques to precisely fabricate micro patterns on planar substrates have been studied. These include EBL, soft lithography, photolithography, and direct-writing. After analyzing preliminary results, two combinational approaches were further investigated. The first method involves the combination of the …