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- Title
- DAGS: AN INFORMATION SYSTEM DESIGN RESEARCH FRAMEWORK SUPPORTING THE DESIGN, DEVELOPMENT AND DELIVERY OF MORE EFFECTIVE INFORMATION SYSTEMS.
- Creator
-
Adams, Lascelles, Cheney, Paul, University of Central Florida
- Abstract / Description
-
Many IT systems fail to realize their objectives because not enough attention has been paid to the business context in which the system functions. One reason expressed - an emphasized technical focus which tend to omit business and organizational issues germane to the organization's and the system's success. When an organization's information system is in line with, and provides support for its business strategy – strategic alignment – superior business performance is...
Show moreMany IT systems fail to realize their objectives because not enough attention has been paid to the business context in which the system functions. One reason expressed - an emphasized technical focus which tend to omit business and organizational issues germane to the organization's and the system's success. When an organization's information system is in line with, and provides support for its business strategy – strategic alignment – superior business performance is often the result. Within the Requirements Engineering (RE) community there has been several attempts to develop and utilize approaches which can illuminate business and organizational informational needs. In this dissertation, the DAGS framework is used to develop an integrated web-based requirements elicitation system which is based on Critical Success Factors (CSFs), Jackson's problem diagrams and organizational strategy analysis technique to represent and model an organization's IT requirements. This research employs the DAGS (multi-methodological approach consisting of Design Science, Action Research, Grounded Theory and System Development research methodologies) framework for Information System (IS) design to assist the Information Technology (IT) department in developing a collaborative user requirements system to assist in designing and constructing more effective information systems by incorporating the needs of various stakeholders in support of organizational goals while satisfying these varied needs. Top management's field of vision is represented in the CSFs which provide a compelling clarification of what is important to the organization. Failure to achieve a CSF directly affects the organization's ability to accomplish its mission; Research shows that alignment of IT systems with business strategy leads to superior organizational performance. Industry professionals have consistently considered alignment of IT with business strategy essential to their success thus requirements for an organization's information systems need to be aligned with the objectives of the business strategy that its stakeholders intend to support. This dissertation contributes to the literature on validating an organization's IT and Business Strategic alignment. It has also provided an example of research, grounded in theory but which is nevertheless relevant to business.
Show less - Date Issued
- 2009
- Identifier
- CFE0002966, ucf:47947
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002966
- Title
- Blockchain-Driven Secure and Transparent Audit Logs.
- Creator
-
Ahmad, Ashar, Mohaisen, David, Awad, Amro, Zhang, Wei, Posey, Clay, University of Central Florida
- Abstract / Description
-
In enterprise business applications, large volumes of data are generated daily, encoding business logic and transactions. Those applications are governed by various compliance requirements, making it essential to provide audit logs to store, track, and attribute data changes. In traditional audit log systems, logs are collected and stored in a centralized medium, making them prone to various forms of attacks and manipulations, including physical access and remote vulnerability exploitation...
Show moreIn enterprise business applications, large volumes of data are generated daily, encoding business logic and transactions. Those applications are governed by various compliance requirements, making it essential to provide audit logs to store, track, and attribute data changes. In traditional audit log systems, logs are collected and stored in a centralized medium, making them prone to various forms of attacks and manipulations, including physical access and remote vulnerability exploitation attacks, and eventually allowing for unauthorized data modification, threatening the guarantees of audit logs. Moreover, such systems, and given their centralized nature, are characterized by a single point of failure. To harden the security of audit logs in enterprise business applications, in this work we explore the design space of blockchain-driven secure and transparent audit logs. We highlight the possibility of ensuring stronger security and functional properties by a generic blockchain system for audit logs, realize this generic design through BlockAudit, which addresses both security and functional requirements, optimize BlockAudit through multi-layered design in BlockTrail, and explore the design space further by assessing the functional and security properties the consensus algorithms through comprehensive evaluations. The first component of this work is BlockAudit, a design blueprint that enumerates structural, functional, and security requirements for blockchain-based audit logs. BlockAudit uses a consensus-driven approach to replicate audit logs across multiple application peers to prevent the single-point-of-failure. BlockAudit also uses the Practical Byzantine Fault Tolerance (PBFT) protocol to achieve consensus over the state of the audit log data. We evaluate the performance of BlockAudit using event-driven simulations, abstracted from IBM Hyperledger. Through the performance evaluation of BlockAudit, we pinpoint a need for high scalability and high throughput. We achieve those requirements by exploring various design optimizations to the flat structure of BlockAudit inspired by real-world application characteristics. Namely, enterprise business applications often operate across non-overlapping geographical hierarchies including cities, counties, states, and federations. Leveraging that, we applied a similar transformation to BlockAudit to fragment the flat blockchain system into layers of codependent hierarchies, capable of processing transactions in parallel. Our hierarchical design, called BlockTrail, reduced the storage and search complexity for blockchains substantially while increasing the throughput and scalability of the audit log system. We prototyped BlockTrail on a custom-built blockchain simulator and analyzed its performance under varying transactions and network sizes demonstrating its advantages over BlockAudit. A recurring limitation in both BlockAudit and BlockTrail is the use of the PBFT consensus protocol, which has high complexity and low scalability features. Moreover, the performance of our proposed designs was only evaluated in computer simulations, which sidestepped the complexities of the real-world blockchain system. To address those shortcomings, we created a generic cloud-based blockchain testbed capable of executing five well-known consensus algorithms including Proof-of-Work, Proof-of-Stake, Proof-of-Elapsed Time, Clique, and PBFT. For each consensus protocol, we instrumented our auditing system with various benchmarks to measure the latency, throughput, and scalability, highlighting the trade-off between the different protocols.
Show less - Date Issued
- 2019
- Identifier
- CFE0007773, ucf:52375
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007773
- Title
- System justification theory: Synthesizing and applying its theoretical motivations in behavioral accounting research.
- Creator
-
Olczak, Wioleta, Roberts, Robin, Libby, Theresa, Tian, Yu, Patten, Dennis, University of Central Florida
- Abstract / Description
-
This dissertation consists of two studies on System Justification Theory, hereafter SJT. SJT (Jost and Banaji 1994) is a psychology theory stating that individuals justify the status quo even if doing so is against their own or their group's interest (Jost et al. 2004). Comprised of twenty propositions, SJT attempts to explain social and psychological factors driving individuals to perceive the social system as legitimate. These factors also drive individuals to support and maintain the...
Show moreThis dissertation consists of two studies on System Justification Theory, hereafter SJT. SJT (Jost and Banaji 1994) is a psychology theory stating that individuals justify the status quo even if doing so is against their own or their group's interest (Jost et al. 2004). Comprised of twenty propositions, SJT attempts to explain social and psychological factors driving individuals to perceive the social system as legitimate. These factors also drive individuals to support and maintain the social system. The synthesis and application of this psychological theory in behavioral accounting research is limited, but could provide explanatory evidence on individual decision-making in accounting. The first study of this dissertation synthesizes SJT's four foundational theories (-) cognitive dissonance, social identity, social dominance, and belief in a just world (-) in behavioral accounting research, specifically focusing on two predominantly used theoretical motivations, cognitive dissonance and social identity theory. Behavioral accounting and corporate social responsibility (CSR) have increasingly become more complex as interest in these two areas continues to grow. The first study reviews prior behavioral accounting research that applied cognitive dissonance or social identity theory, and then demonstrates how the application of SJT in behavioral accounting research addresses more complex research questions that cannot be addressed solely from one or a combination of SJT's four foundational theories. The second study then applies SJT's theoretical motivations in a complex managerial accounting setting by investigating whether maintaining the status quo is a factor explaining managers' decisions to overstate environmental capital expenditure (ECE) projections. This study uses an experimental design to understand whether the presence of an overstatement status quo and a system threat affects managers' decisions to overstate environmental projections. The results indicate that managers are more likely to overstate ECE projections when the industry exhibits an overstatement status quo. Additionally, this propensity to overstate ECE projections is further exacerbated when managers face a stakeholder threat, suggesting they (")dig in their heels(") and maintain the status quo. This study extends environmental accounting research by demonstrating that the societal status quo affects managers cognitively and psychologically as they make environmental disclosure decisions. Results also contribute to practice by shedding insight as to why managers make certain environmental disclosure decisions. Specifically, the results show that the social system impacts managers' willingness to use environmental disclosures as a legitimating tool. Overall these two studies contribute to behavioral accounting research by exploring and applying a psychological theory in a managerial environmental accounting setting. It demonstrates how a commonly used psychology theory that has never been utilized in accounting research could address broad and complex accounting topics
Show less - Date Issued
- 2019
- Identifier
- CFE0007697, ucf:52447
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007697
- Title
- An investigation into a least squares method for image registration.
- Creator
-
Cordon, Ernest William, Patz, B.W., Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis; One of the problems associated with the automatic image processing of satellite photographs such as weather maps is the need for image registration; that is, the fitting of a map that has some translational and rotational bias to a known data base. This paper investigates a least square method of image registration using an image that has been converted into a boundary map with a pixel representation 1 for land, -1 for water and...
Show moreFlorida Technological University College of Engineering Thesis; One of the problems associated with the automatic image processing of satellite photographs such as weather maps is the need for image registration; that is, the fitting of a map that has some translational and rotational bias to a known data base. This paper investigates a least square method of image registration using an image that has been converted into a boundary map with a pixel representation 1 for land, -1 for water and zero for cloud pixels. A sampled correlation array is constructed by shifting the weather map to locations on a given grid, centered around a sampled correlation peak, and performing an accumulation of the pixel-by-pixel comparisons between the weather map and its data base over the whole map or a smaller search window. A least square approximation 0 f the translational and rotational bias is performed using the data from this sampled correlation array, fitted against the shape of an elliptical cone.
Show less - Date Issued
- 1978
- Identifier
- CFR0003516, ucf:53005
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0003516
- Title
- Realization of a fast automatic correlation algorithm for registration of satellite images.
- Creator
-
Kassak, John E., Patz, B.W., Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis; The requirement for a fast automated correlation algorithm for registration of satellite images is discussed. An overview of current registration techniques is presented indicating a correlator, matching binary maps compressed from the original imagery, may provide the required throughput when implemented with a dedicated hardware/processor. An actual registration problem utilizing GOES digitally processed imagery is chosen and...
Show moreFlorida Technological University College of Engineering Thesis; The requirement for a fast automated correlation algorithm for registration of satellite images is discussed. An overview of current registration techniques is presented indicating a correlator, matching binary maps compressed from the original imagery, may provide the required throughput when implemented with a dedicated hardware/processor. An actual registration problem utilizing GOES digitally processed imagery is chosen and defined. The realization of a fast correlator, matching image input data with sampled data base reference image data in real time is considered.
Show less - Date Issued
- 1978
- Identifier
- CFR0003495, ucf:53010
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0003495
- Title
- Research on Improving Reliability, Energy Efficiency and Scalability in Distributed and Parallel File Systems.
- Creator
-
Zhang, Junyao, Wang, Jun, Zhang, Shaojie, Lee, Jooheung, University of Central Florida
- Abstract / Description
-
With the increasing popularity of cloud computing and "Big data" applications, current data centers are often required to manage petabytes or exabytes of data. To store this huge amount of data, thousands or tens of thousands storage nodes are required at a single site. This imposes three major challenges for storage system designers: (1) Reliability---node failure in these datacenters is a normal occurrence rather than a rare situation. This makes data reliability a great concern. (2) Energy...
Show moreWith the increasing popularity of cloud computing and "Big data" applications, current data centers are often required to manage petabytes or exabytes of data. To store this huge amount of data, thousands or tens of thousands storage nodes are required at a single site. This imposes three major challenges for storage system designers: (1) Reliability---node failure in these datacenters is a normal occurrence rather than a rare situation. This makes data reliability a great concern. (2) Energy efficiency---a data center can consume up to 100 times more energy than a standard office building. More than 10% of this energy consumption can be attributed to storage systems. Thus, reducing the energy consumption of the storage system is key to reducing the overall consumption of the data center.(3) Scalability---with the continuously increasing size of data, maintaining the scalability of the storage systems is essential. That is, the expansion of the storage system should be completed efficiently and without limitations on the total number of storage nodes or performance.This thesis proposes three ways to improve the above three key features for current large-scale storage systems. Firstly, we define the problem of "reverse lookup", namely finding the list of objects (blocks) for a failed node. As the first step of failure recovery, this process is directly related to the recovery/reconstruction time. While existing solutions use metadata traversal or data distribution reversing methods for reverse lookup, which are either time consuming or expensive, a deterministic block placement can achieve fast and efficient reverse lookup.However, the deterministic placement solutions are designed for centralized, small-scale storage architectures such as RAID etc.. Due to their lacking of scalability, they cannot be directly applied in large-scale storage systems. In this paper, we propose Group-Shifted Declustering (G-SD), a deterministic data layout for multi-way replication. G-SD addresses the scalability issue of our previous Shifted Declustering layout and supports fast and efficient reverse lookup.Secondly, we define a problem: "how to balance the performance, energy, and recovery in degradation mode for an energy efficient storage system?". While extensive researches have been proposed to tradeoff performance for energy efficiency under normal mode, the system enters degradation mode when node failure occurs, in which node reconstruction is initiated. This very process requires a number of disks to be spun up and requires a substantial amount of I/O bandwidth, which will not only compromise energy efficiency but also performance. Without considering the I/O bandwidth contention between recovery and performance, we find that the current energy proportional solutions cannot answer this question accurately. This thesis present PERP, a mathematical model to minimize the energy consumption for a storage systems with respect to performance and recovery. PERP answers this problem by providing the accurate number of nodes and the assigned recovery bandwidth at each time frame.Thirdly, current distributed file systems such as Google File System(GFS) and Hadoop Distributed File System (HDFS), employ a pseudo-random method for replica distribution and a centralized lookup table (block map) to record all replica locations. This lookup table requires a large amount of memory and consumes a considerable amount of CPU/network resources on the metadata server. With the booming size of "Big Data", the metadata server becomes a scalability and performance bottleneck. While current approaches such as HDFS Federation attempt to "horizontally" extend scalability by allowing multiple metadata servers, we believe a more promising optimization option is to "vertically" scale up each metadata server. We propose Deister, a novel block management scheme that builds on top of a deterministic declustering distribution method Intersected Shifted Declustering (ISD). Thus both replica distribution and location lookup can be achieved without a centralized lookup table.
Show less - Date Issued
- 2015
- Identifier
- CFE0006238, ucf:51082
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006238
- Title
- investigation of dual-stage high efficiency (&)density micro inverter for solar application.
- Creator
-
Chen, Lin, Batarseh, Issa, Mikhael, Wasfy, Wu, Xinzhang, Behal, Aman, Kutkut, Nasser, University of Central Florida
- Abstract / Description
-
Module integrated converters (MIC), also called micro inverter, in single phase have witnessed recent market success due to unique features (1) improved energy harvest, (2) improved system efficiency, (3) lower installation costs, (4) plug-N-play operation, (5) and enhanced flexibility and modularity. The MIC sector has grown from a niche market to mainstream, especially in the United States. Due to the fact that two-stage architecture is commonly used for single phase MIC application. A DC...
Show moreModule integrated converters (MIC), also called micro inverter, in single phase have witnessed recent market success due to unique features (1) improved energy harvest, (2) improved system efficiency, (3) lower installation costs, (4) plug-N-play operation, (5) and enhanced flexibility and modularity. The MIC sector has grown from a niche market to mainstream, especially in the United States. Due to the fact that two-stage architecture is commonly used for single phase MIC application. A DC-DC stage with maximum power point tracking to boost the output voltage of the Photovoltaic (PV) panel is employed in the first stage, DC-AC stage is used for use to connect the grid or the residential application. As well known, the cost of MIC is key issue compared to convention PV system, such as the architecture: string inverter or central inverter. A high efficiency and density DC-DC converter is proposed and dedicated for MIC application. Assuming further expansion of the MIC market, this dissertation presents the micro-inverter concept incorporated in large size PV installations such as MW-class solar farms where a three phase AC connection is employed. A high efficiency three phase MIC with two-stage ZVS operation for grid tied photovoltaic system is proposed which will reduce cost per watt, improve reliability, and increase scalability of MW-class solar farms through the development of new solar farm system architectures. This dissertation presents modeling and triple-loop control for a high efficiency three-phase four-wire inverter for use in grid-connected two-stage micro inverter applications. An average signal model based on a synchronous rotation frame for a three-phase four-wire inverter has been developed. The inner current loop consists of a variable frequency bidirectional current mode (VFBCM) controller which regulates output filter inductor current thereby achieving ZVS, improved system response, and reduced grid current THD. Active damping of the LCL output filter using filter inductor current feedback is discussed along with small signal modeling of the proposed control method. Since the DC-link capacitor plays a critical role in two-stage micro inverter applications, a DC-link controller is implemented outside of the two current control loops to keep the bus voltage constant. In the end, simulation and experimental results from a 400 watt prototype are presented to verify the validity of the theoretical analysis.
Show less - Date Issued
- 2014
- Identifier
- CFE0005148, ucf:50699
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005148
- Title
- Vehicle Tracking and Classification via 3D Geometries for Intelligent Transportation Systems.
- Creator
-
Mcdowell, William, Mikhael, Wasfy, Jones, W Linwood, Haralambous, Michael, Atia, George, Mahalanobis, Abhijit, Muise, Robert, University of Central Florida
- Abstract / Description
-
In this dissertation, we present generalized techniques which allow for the tracking and classification of vehicles by tracking various Point(s) of Interest (PoI) on a vehicle. Tracking the various PoI allows for the composition of those points into 3D geometries which are unique to a given vehicle type. We demonstrate this technique using passive, simulated image based sensor measurements and three separate inertial track formulations. We demonstrate the capability to classify the 3D...
Show moreIn this dissertation, we present generalized techniques which allow for the tracking and classification of vehicles by tracking various Point(s) of Interest (PoI) on a vehicle. Tracking the various PoI allows for the composition of those points into 3D geometries which are unique to a given vehicle type. We demonstrate this technique using passive, simulated image based sensor measurements and three separate inertial track formulations. We demonstrate the capability to classify the 3D geometries in multiple transform domains (PCA (&) LDA) using Minimum Euclidean Distance, Maximum Likelihood and Artificial Neural Networks. Additionally, we demonstrate the ability to fuse separate classifiers from multiple domains via Bayesian Networks to achieve ensemble classification.
Show less - Date Issued
- 2015
- Identifier
- CFE0005976, ucf:50790
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005976
- Title
- Dynamic Modeling Approach to Quantify Change Orders Impact on Labor Productivity.
- Creator
-
Al-Kofahi, Zain, Oloufa, Amr, Tatari, Omer, Uddin, Nizam, Xanthopoulos, Petros, University of Central Florida
- Abstract / Description
-
In construction projects, change orders are commonly faced. These change orders, which are issued by the owner, may cause interruption to the contractor's work, resulting in damages such as loss of labor productivity, delay damages, and cost overruns which may lead to claims. The relationship between change orders and loss of labor productivity is not well understood because of the difficulty in linking the cause of the productivity loss to the change order. So, to receive compensation, the...
Show moreIn construction projects, change orders are commonly faced. These change orders, which are issued by the owner, may cause interruption to the contractor's work, resulting in damages such as loss of labor productivity, delay damages, and cost overruns which may lead to claims. The relationship between change orders and loss of labor productivity is not well understood because of the difficulty in linking the cause of the productivity loss to the change order. So, to receive compensation, the contractor needs to prove with a credible calculation that the productivity loss was a result of the change order issued by the owner. Compared to all available productivity loss quantification methods, the (")Measured Mile(") approach is considered the most acceptable and popular approach in litigation. In this study, loss of labor productivity due to change orders is studied using a system dynamics method. A system dynamics model is developed using Vensim Software, validated, and utilized to quantitatively measure the impact of the change in the project scope on labor productivity. Different road construction projects were analyzed using both methods: measured mile analysis and system dynamics model; then, the results from those two approaches were compared
Show less - Date Issued
- 2016
- Identifier
- CFE0006430, ucf:51448
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006430
- Title
- SYSTEMS DESIGN: ACADEMIC ADVISING SYSTEM IMPLEMENTATION, A CASE STUDY OF USER CENTERED SYSTEM DESIGN AT THE UNIVERSITY OF CENTRAL FLORIDA.
- Creator
-
Jones, Tracy, Boote, David, Hayes, Grant, Little, Mary, Vitale, Thomas, University of Central Florida
- Abstract / Description
-
This dissertation presents a case study in user-centered design completed at the University of Central Florida. Leadership in the College of Graduate Studies at UCF realized the need for an advisement tool to assist advisors in the academic colleges to track the success of their students.After an advisement product was selected, the user-centered design approach started to be implemented. End-users were shown the basic functionality and known benefits of the product. Then they were asked how...
Show moreThis dissertation presents a case study in user-centered design completed at the University of Central Florida. Leadership in the College of Graduate Studies at UCF realized the need for an advisement tool to assist advisors in the academic colleges to track the success of their students.After an advisement product was selected, the user-centered design approach started to be implemented. End-users were shown the basic functionality and known benefits of the product. Then they were asked how they could make it standardized across programs. The users selected the order in which information and degree requirements should display. The users asked for additional information to be shown on the new advising report called the Graduate Plan of Study (GPS). This information would assist them in advising students and certifying that the students' had met requirements to earn their degree.With the help of the end-users, a prototype was developed and delivered to computer services. End users assisted with the testing of current and additional functionality. After attending focus groups, the end-users had a better understanding of the need for testing. They assisted in providing ideas for training and a deployment plan to the university. The use of the user-centered design approach helped to keep our end-users engaged in the project. They were the central cause of the successful implementation of a new advisement module for graduate students at UCF.
Show less - Date Issued
- 2015
- Identifier
- CFE0005637, ucf:50230
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005637
- Title
- A Framework For Workforce Management An Agent Based Simulation Approach.
- Creator
-
Marin, Mario, Rabelo, Luis, Lee, Gene, Elshennawy, Ahmad, Kincaid, John, University of Central Florida
- Abstract / Description
-
In today's advanced technology world, enterprises are in a constant state of competition. As the intensity of competition increases the need to continuously improve organizational performance has never been greater. Managers at all levels must be on a constant quest for finding ways to maximize their enterprises' strategic resources. Enterprises can develop sustained competitiveness only if their activities create value in unique ways. There should be an emphasis to transfer this...
Show moreIn today's advanced technology world, enterprises are in a constant state of competition. As the intensity of competition increases the need to continuously improve organizational performance has never been greater. Managers at all levels must be on a constant quest for finding ways to maximize their enterprises' strategic resources. Enterprises can develop sustained competitiveness only if their activities create value in unique ways. There should be an emphasis to transfer this competitiveness to the resources it has on hand and the resources it can develop to be used in this environment. The significance of human capital is even greater now, as the intangible value and the tacit knowledge of enterprises' resources should be strategically managed to achieve a greater level of continuous organizational success. This research effort seeks to provide managers with means for accurate decision making for their workforce management. A framework for modeling and managing human capital to achieve effective workforce planning strategies is built to assist enterprise in their long term strategic organizational goals.
Show less - Date Issued
- 2014
- Identifier
- CFE0005375, ucf:50439
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005375
- Title
- Exploring new boundaries in team cognition: Integrating knowledge in distributed teams.
- Creator
-
Zajac, Stephanie, Salas, Eduardo, Bowers, Clint, Burke, Shawn, University of Central Florida
- Abstract / Description
-
Distributed teams continue to emerge in response to the complex organizational environments brought about by globalization, technological advancements, and the shift toward a knowledge-based economy. These teams are comprised of members who hold the disparate knowledge necessary to take on cognitively demanding tasks. However, knowledge coordination between team members who are not co-located is a significant challenge, often resulting in process loss and decrements to the effectiveness of...
Show moreDistributed teams continue to emerge in response to the complex organizational environments brought about by globalization, technological advancements, and the shift toward a knowledge-based economy. These teams are comprised of members who hold the disparate knowledge necessary to take on cognitively demanding tasks. However, knowledge coordination between team members who are not co-located is a significant challenge, often resulting in process loss and decrements to the effectiveness of team level knowledge structures. The current effort explores the configuration dimension of distributed teams, and specifically how subgroup formation based on geographic location, may impact the effectiveness of a team's transactive memory system and subsequent team process. In addition, the role of task cohesion as a buffer to negative intergroup interaction is explored.
Show less - Date Issued
- 2014
- Identifier
- CFE0005449, ucf:50393
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005449
- Title
- Characterization of Dynamic Structures Using Parametric and Non-parametric System Identification Methods.
- Creator
-
Al Rumaithi, Ayad, Yun, Hae-Bum, Catbas, Necati, Mackie, Kevin, University of Central Florida
- Abstract / Description
-
The effects of soil-foundation-structure (SFS) interaction and extreme loading on structural behaviors are important issues instructural dynamics. System identification is an important technique to characterize linear and nonlinear dynamic structures.The identification methods are usually classified into the parametric and non-parametric approaches based on how to modeldynamic systems. The objective of this study is to characterize the dynamic behaviors of two realistic civil...
Show moreThe effects of soil-foundation-structure (SFS) interaction and extreme loading on structural behaviors are important issues instructural dynamics. System identification is an important technique to characterize linear and nonlinear dynamic structures.The identification methods are usually classified into the parametric and non-parametric approaches based on how to modeldynamic systems. The objective of this study is to characterize the dynamic behaviors of two realistic civil engineeringstructures in SFS configuration and subjected to impact loading by comparing different parametric and non-parametricidentification results. First, SFS building models were studied to investigate the effects of the foundation types on the structural behaviors underseismic excitation. Three foundation types were tested including the fixed, pile and box foundations on a hydraulic shaketable, and the dynamic responses of the SFS systems were measured with the instrumented sensing devices.Parametric modal analysis methods, including NExT-ERA, DSSI, and SSI, were studied as linear identification methodswhose governing equations were modeled based on linear equations of motion. NExT-ERA, DSSI, and SSI were used toanalyze earthquake-induced damage effects on the global behavior of the superstructures for different foundation types.MRFM was also studied to characterize the nonlinear behavior of the superstructure during the seismic events. MRFM is anonlinear non-parametric identification method which has advantages to characterized local nonlinear behaviors using theinterstory stiffness and damping phase diagrams. The major findings from the SFS study are: *The investigated modal analysis methods identified the linearized version of the model behavior. The change of globalstructural behavior induced by the seismic damage could be quantified through the modal parameter identification. Thefoundation types also affected the identification results due to different SFS interactions. The identification accuracy wasreduced as the nonlinear effects due to damage increased. *MRFM could characterize the nonlinear behavior of the interstory restoring forces. The localized damage could bequantified by measuring dissipated energy of each floor. The most severe damage in the superstructure was observed withthe fixed foundation. Second, the responses of a full-scale suspension bridge in a ship-bridge collision accident were analyzed to characterizethe dynamic properties of the bridge. Three parametric and non-parametric identification methods, NExT-ERA, PCA andICA were used to process the bridge response data to evaluate the performance of mode decomposition of these methodsfor traffic, no-traffic, and collision loading conditions. The PCA and ICA identification results were compared with those ofNExT-ERA method for different excitation, response types, system damping and sensor spatial resolution. The major findings from the ship-bridge collision study include: *PCA was able to characterize the mode shapes and modal coordinates for velocity and displacement responses. Theresults using the acceleration were less accurate. The inter-channel correlation and sensor spatial resolution had significanteffects on the mode decomposition accuracy. *ICA showed the lowest performance in this mode decomposition study. It was observed that the excitation type andsystem characteristics significantly affected the ICA accuracy.
Show less - Date Issued
- 2014
- Identifier
- CFE0005567, ucf:50295
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005567
- Title
- AN INVESTIGATION TO DETERMINE THE LEVEL OF KNOWLEDGE OF FACILITY MAINTENANCE BY PUBLIC SCHOOL-BUILDING LEVEL ADMINISTRATORS.
- Creator
-
Paradise, Richard, Murray, Kenneth, University of Central Florida
- Abstract / Description
-
This investigation studied the level of knowledge that principals have concerning the maintenance of their schools. A questionnaire was developed to address three research questions. These research questions were: (1) what is the extent that facilities maintenance is an important issue for school principals? (2) in what specific areas of facilities maintenance do principals lack knowledge? and (3) in what specific areas does the lack of facilities maintenance knowledge by principals exceed 30...
Show moreThis investigation studied the level of knowledge that principals have concerning the maintenance of their schools. A questionnaire was developed to address three research questions. These research questions were: (1) what is the extent that facilities maintenance is an important issue for school principals? (2) in what specific areas of facilities maintenance do principals lack knowledge? and (3) in what specific areas does the lack of facilities maintenance knowledge by principals exceed 30%? A questionnaire was developed to gather data to analyze comparative relationships to the research questions. Data indicated that principals do believe facilities maintenance is an important issue. Reponses to the questionnaire indicated most principals have a general understanding of facilities maintenance in its broadest sense. However, the data supported that most principals lack knowledge concerning the specific facilities maintenance information and issues. Recommendations were made to address the lack of knowledge principals have concerning facilities maintenance. Recommendations were also made for additional research in the area of the principal's knowledge concerning facilities maintenance.
Show less - Date Issued
- 2006
- Identifier
- CFE0001200, ucf:46943
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001200
- Title
- FORMALIZATION OF INPUT AND OUTPUT IN MODERN OPERATING SYSTEMS: THE HADLEY MODEL.
- Creator
-
Gerber, Matthew, Leeson, John, University of Central Florida
- Abstract / Description
-
We present the Hadley model, a formal descriptive model of input and output for modern computer operating systems. Our model is intentionally inspired by the Open Systems Interconnection model of networking; I/O as a process is defined as a set of translations between a set of computer-sensible forms, or layers, of information. To illustrate an initial application domain, we discuss the utility of the Hadley model and a potential associated I/O system as a tool for digital forensic...
Show moreWe present the Hadley model, a formal descriptive model of input and output for modern computer operating systems. Our model is intentionally inspired by the Open Systems Interconnection model of networking; I/O as a process is defined as a set of translations between a set of computer-sensible forms, or layers, of information. To illustrate an initial application domain, we discuss the utility of the Hadley model and a potential associated I/O system as a tool for digital forensic investigators. To illustrate practical uses of the Hadley model we present the Hadley Specification Language, an essentially functional language designed to allow the translations that comprise I/O to be written in a concise format allowing for relatively easy verifiability. To further illustrate the utility of the language we present a read/write Microsoft DOS FAT12 and read-only Linux ext2 file system specification written in the new format. We prove the correctness of the read-only side of these descriptions. We present test results from operation of our HSL-driven system both in user mode on stored disk images and as part of a Linux kernel module allowing file systems to be read. We conclude by discussing future directions for the research.
Show less - Date Issued
- 2005
- Identifier
- CFE0000392, ucf:46339
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000392
- Title
- EARLY INTERVENTION SYSTEMS: AN EVALUATIVE REVIEW OF THEIR HISTORY AND USE.
- Creator
-
Ceriale, Matthew A., Paoline, Eugene, University of Central Florida
- Abstract / Description
-
It is the intention of this thesis to effectively describe what is known about EI systems to date. Many sources of information are used, beginning with peer reviewed journals such as Justice Quarterly, Police Quarterly, Policing: An International Journal of Police Strategies & Management, Police and Society and The American Journal of Criminal Justice. Also reports from criminal justice research affiliates will be used like the National Institute of Justice and the National Criminal Justice...
Show moreIt is the intention of this thesis to effectively describe what is known about EI systems to date. Many sources of information are used, beginning with peer reviewed journals such as Justice Quarterly, Police Quarterly, Policing: An International Journal of Police Strategies & Management, Police and Society and The American Journal of Criminal Justice. Also reports from criminal justice research affiliates will be used like the National Institute of Justice and the National Criminal Justice Reference Service. This thesis will work towards creating a comprehensive outline of the history of EI and future possibilities. With the aid of extant research, inquiries into the effectiveness of various EI systems, their shortcomings, or even best practices will be addressed. The aim is to review the existing discussion essentially paving the way for future researchers to conduct primary research studies on EI effectiveness. By accumulating, and subsequently compiling available research, the hope is to identify key arguments and perspectives on these systems and their implementation.
Show less - Date Issued
- 2016
- Identifier
- CFH2000032, ucf:45605
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000032
- Title
- Reliability and Robustness Enhancement of Cooperative Vehicular Systems: A Bayesian Machine Learning Perspective.
- Creator
-
Nourkhiz Mahjoub, Hossein, Pourmohammadi Fallah, Yaser, Vosoughi, Azadeh, Yuksel, Murat, Atia, George, Eluru, Naveen, University of Central Florida
- Abstract / Description
-
Autonomous vehicles are expected to greatly transform the transportation domain in the near future. Some even envision that the human drivers may be fully replaced by automated systems. It is plausible to assume that at least a significant part of the driving task will be done by automated systems in not a distant future. Although we are observing a rapid advance towards this goal, which gradually pushes the traditional human-based driving toward more advanced autonomy levels, the full...
Show moreAutonomous vehicles are expected to greatly transform the transportation domain in the near future. Some even envision that the human drivers may be fully replaced by automated systems. It is plausible to assume that at least a significant part of the driving task will be done by automated systems in not a distant future. Although we are observing a rapid advance towards this goal, which gradually pushes the traditional human-based driving toward more advanced autonomy levels, the full autonomy concept still has a long way before being completely fulfilled and realized due to numerous technical and societal challenges. During this long transition phase, blended driving scenarios, composed of agents with different levels of autonomy, seems to be inevitable. Therefore, it is critical to design appropriate driving systems with different levels of intelligence in order to benefit all participants. Vehicular safety systems and their more advanced successors, i.e., Cooperative Vehicular Systems (CVS), have originated from this perspective. These systems aim to enhance the overall quality and performance of the current driving situation by incorporating the most advanced available technologies, ranging from on-board sensors such as radars, LiDARs, and cameras to other promising solutions e.g. Vehicle-to-Everything (V2X) communications. However, it is still challenging to attain the ideal anticipated benefits out of the cooperative vehicular systems, due to the inherent issues and challenges of their different components, such as sensors' failures in severe weather conditions or the poor performance of V2X technologies under dense communication channel loads. In this research we aim to address some of these challenges from a Bayesian Machine- Learning perspective, by proposing several novel ideas and solutions which facilitate the realization of more robust, reliable, and agile cooperative vehicular systems. More precisely, we have a two-fold contribution here. In one aspect, we have investigated the notion of Model-Based Communications (MBC) and demonstrated its effectiveness for V2X communication performance enhancement. This improvement is achieved due to the more intelligent communication strategy of MBC in comparison with the current state-of-the-art V2X technologies. Essentially, MBC proposes a conceptual change in the nature of the disseminated and shared information over the communication channel compared to what is being disseminated in current technologies. In the MBC framework, instead of sharing the raw dynamic information among the network agents, each agent shares the parameters of a stochastic forecasting model which represents its current and future behavior and updates these parameters as needed. This model sharing strategy enables the receivers to precisely predict the future behaviors of the transmitter even when the update frequency is very low. On the other hand, we have also proposed receiver-side solutions in order to enhance the CVS performance and reliability and mitigate the issues caused by imperfect communication and detection processes. The core concept for these solutions is incorporating other informative elements in the system to compensate for the lack of information which is lost during the imperfect communication or detection phases. For proof of concept, we have designed an adaptive FCW framework which considers the driver's feedbacks to the CVS system. This adaptive framework mitigates the negative impact of imperfectly received or detected information on system performance, using the inherent information of these feedbacks and responses. The effectiveness and superiority of this adaptive framework over traditional design has been demonstrated in this research.
Show less - Date Issued
- 2019
- Identifier
- CFE0007845, ucf:52807
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007845
- Title
- Computer Simulation of 911 Emergency Telephone System for Orange County, Florida.
- Creator
-
Veillette, Ronald J., null, null, Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis; The State of Florida has mandated that a statewide 911 system be implemented, and the Department of General Services, Division of Communications, has performed a study of possible 911 system configurations for Orange County based on the findings of a study performed by the Stanford Research Institute for the whole of the State of Florida. The Orange County study determined operator manning levels of the primary law enforcement...
Show moreFlorida Technological University College of Engineering Thesis; The State of Florida has mandated that a statewide 911 system be implemented, and the Department of General Services, Division of Communications, has performed a study of possible 911 system configurations for Orange County based on the findings of a study performed by the Stanford Research Institute for the whole of the State of Florida. The Orange County study determined operator manning levels of the primary law enforcement agencies involved in the system and response times to citizen calls for each of the configurations proposed. This research generated computer simulation models of the two most likely to be implemented configurations for handling citizen calls. The models were run sing the input parameters defined in the Orange County study, and the results compared favorably. Additional runs were made with varying resource assignments to evaluate call service with respect to the level of performance and response time. The models were designed in modular form, such that they can easily be structured to conform to other operational configurations. This will allow evaluation of prosed systems prior to actual start up and analysis of resource requirements based on population predictions.
Show less - Date Issued
- 1977
- Identifier
- CFR0004777, ucf:52962
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0004777
- Title
- System for metal coated fiber fabrication.
- Creator
-
Zhang, Da, Amezcua Correa, Rodrigo, Schulzgen, Axel, Shah, Lawrence, University of Central Florida
- Abstract / Description
-
For many specific applications, such as sensors, aerospace, chemical industry, deep-well oil-field industry, metal-coated fiber shows strong abilities to satisfy people's requirement. With in-line coating technology, we are able to coat Aluminum on the fibers.Using electromagnetic induction, we can easily heat an electrically conducting thing such as a metal with the eddy current. This process is defined as Induction heating. And we will melt the Aluminum by this induction heating during...
Show moreFor many specific applications, such as sensors, aerospace, chemical industry, deep-well oil-field industry, metal-coated fiber shows strong abilities to satisfy people's requirement. With in-line coating technology, we are able to coat Aluminum on the fibers.Using electromagnetic induction, we can easily heat an electrically conducting thing such as a metal with the eddy current. This process is defined as Induction heating. And we will melt the Aluminum by this induction heating during drawing the fibers on the tower. Introduce the fiber tower system. The drawing process of in-line technology is formed of the following steps: Position, Melting, Forming into fibers, Checking the diameter, Revising, Protective coatings. We will follow these to make the Aluminum coating fiber.With the help of the software which is 123D Design, I have four 3D model of the coating systems. Show the details of the all the coating systems such as the shape and the length of coated-fiber we can get.Talk about the photonic lantern which is the first project that I took part in when I joined the group. Show the mode profiles of our 6 to 1 lantern.
Show less - Date Issued
- 2017
- Identifier
- CFE0006677, ucf:51251
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006677
- Title
- A Holistic Framework for Transitional Management.
- Creator
-
Elattar, Ahmed, Rabelo, Luis, Pazour, Jennifer, Mollaghasemi, Mansooreh, Ajayi, Richard, University of Central Florida
- Abstract / Description
-
For all business organizations, there comes a time when a change must take place within their eco-system. It consumes a great deal of thought and planning to ensure that the right decision is made as it could alter the entire course of their business for a number of years to come. This change may appear in the form of a brilliant CEO reaching the age of retirement, or an unsuccessful Managing Director being asked to leave before fulfilling the term of her contract. Regardless of the cause, a...
Show moreFor all business organizations, there comes a time when a change must take place within their eco-system. It consumes a great deal of thought and planning to ensure that the right decision is made as it could alter the entire course of their business for a number of years to come. This change may appear in the form of a brilliant CEO reaching the age of retirement, or an unsuccessful Managing Director being asked to leave before fulfilling the term of her contract. Regardless of the cause, a transition must occur in which a suitable successor is chosen and put into place while minimizing costs, satisfying stakeholders, ensuring that the successor has been adequately prepared for their new position, and minimizing work place gossip, among other things. It is also important to understand how the nature of the business, as well as its financial standing, effects such a transition.Engineering and management principles come together in this study to ensure that organizations going through such a change are on the right course. As the problem of transitional management is not one of concrete values and contains many ambiguous concepts, one way to tackle the problem is by utilizing various industrial engineering methodologies that allow these companies to systematically begin preparing for such a change. By default, organizational strategy has to change, technology is continually being renewed and it becomes very hard for the same leader to constantly implement new and innovative developments.Organizations today have a very poor understanding of where they currently stand and as a result the cause for a company's lack of profitability is often overlooked with time and money being wasted in an attempt to fix something that is not broken. To be able to look at the bigger picture of an organization and from there begin to close in on the main problems causing a negative impact, the Matrix of Change is used and takes in many factors to layout an accurate representation of the direction in which an organization should be headed and how it can continue to grow and remain successful. The Theory of Constraints on the other hand is used here as a step-by-step guide allowing companies to be better organized during times of change. And System Dynamics modeling is where these companies can begin to simulate and solve the dilemma of transitional management using causal loop diagrams and stock and flow diagrams.Through such tools a framework can begin to be developed, one that is valued by corporations and continually reviewed. Several case studies, simulation modeling, and a panel of experts were used in order to demonstrate and validate this framework.
Show less - Date Issued
- 2014
- Identifier
- CFE0005160, ucf:50708
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005160
