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- Title
- Systems Geometry: A Methodology for Analyzing Emergent System of Systems Behaviors.
- Creator
-
Bouwens, Christina, Sepulveda, Jose, Karwowski, Waldemar, Xanthopoulos, Petros, Kapucu, Naim, University of Central Florida
- Abstract / Description
-
Recent advancements in technology have led to the increased use of integrated 'systems of systems' (SoS) which link together independently developed and usable capabilities into an integrated system that exhibits new, emergent capabilities. However, the resulting SoS is often not well understood, where secondary and tertiary effects of tying systems together are often unpredictable and present severe consequences. The complexities of the composed system stem not only from system integration,...
Show moreRecent advancements in technology have led to the increased use of integrated 'systems of systems' (SoS) which link together independently developed and usable capabilities into an integrated system that exhibits new, emergent capabilities. However, the resulting SoS is often not well understood, where secondary and tertiary effects of tying systems together are often unpredictable and present severe consequences. The complexities of the composed system stem not only from system integration, but from a broad range of areas such as the competing objectives of different constituent system stakeholders, mismatched requirements from multiple process models, and architectures and interface approaches that are incompatible on multiple levels. While successful SoS development has proven to be a valuable tool for a wide range of applications, there are significant problems that remain with the development of such systems that need to be addressed during the early stages of engineering development within such environments. The purpose of this research is to define and demonstrate a methodology called Systems Geometry (SG) for analyzing SoS in the early stages of development to identify areas of potential unintended emergent behaviors as candidates for the employment of risk management strategies. SG focuses on three dimensions of interest when planning the development of a SoS: operational, functional, and technical. For Department of Defense (DoD) SoS, the operational dimension addresses the warfighter environment and includes characteristics such as mission threads and related command and control or simulation activities required to support the mission. The functional dimension highlights different roles associated with the development and use of the SoS, which could include a participant warfighter using the system, an analyst collecting data for system evaluation, or an infrastructure engineer working to keep the SoS infrastructure operational to support the users. Each dimension can be analyzed to understand roles, interfaces and activities. Cross-dimensional effects are of particular interest since such effects are less detectable and generally not addressed with conventional systems engineering (SE) methods. The literature review and the results of this study have identified key characteristics or dimensions that should be examined during SoS analysis and design. Although many methods exist for exploring system dimensions, there is a gap in techniques to explore cross-dimensional interactions and their effect on emergent SoS behaviors. The study has resulted in a methodology for capturing dimensional information and recommended analytical methods for intra-dimensional as well as cross-dimensional analysis. A problem-based approach to the system analysis is recommended combined with the application of matrix methods, network analysis and modeling techniques to provide intra- and cross-dimensional insight. The results of this research are applicable to a variety of socio-technical SoS analyses with applications in analysis, experimentation, test and evaluation and training.
Show less - Date Issued
- 2013
- Identifier
- CFE0005135, ucf:50696
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005135
- Title
- ASCERTAINING THE GROWTH OF A COMPANYA SYSTEM DYNAMICS APPRAOCH.
- Creator
-
Noor Mohideen, Fakir Mohideen, Rabelo, Luis, University of Central Florida
- Abstract / Description
-
Business is often about creating change for other businesses. At times, these changes affect only the company and at other times they affect the entire industry. There is a time in the life of a business when its fundamental way of functioning is questioned and is subjected to change. That change can mean an opportunity to rise to new heights, or it might even signal the beginning of the end. This fundamental change in any business is known as an inflection point. Understanding the nature of...
Show moreBusiness is often about creating change for other businesses. At times, these changes affect only the company and at other times they affect the entire industry. There is a time in the life of a business when its fundamental way of functioning is questioned and is subjected to change. That change can mean an opportunity to rise to new heights, or it might even signal the beginning of the end. This fundamental change in any business is known as an inflection point. Understanding the nature of its inflection point and responding to that point suitably will help to safeguard a company's growth. So today's managers, when faced with such changes, have to be equipped with the adequate tools to guide the company out of troubles and to place it in a position where it can prosper. The fundamental changes can be scrutinized by studying the internal dynamic behavior of the system. Therefore, the managers are required to be systems thinkers so that they can study the internal dynamic behavior of the company and maneuver the inflection point successfully. System dynamics is an effective tool, which helps the managers to understand the structure and internal dynamic behaviors of a large and complex system. System dynamics models are developed to assist the management to navigate its way through the inflection point. This thesis focuses on how system dynamics model-analysis and model based policy development process can help a company to overcome an inflection point. Further enhancements and calibrations can be done to the model to provide industry specific solutions.
Show less - Date Issued
- 2005
- Identifier
- CFE0000335, ucf:46300
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000335
- Title
- Model-Based Systems Engineering Approach to Distributed and Hybrid Simulation Systems.
- Creator
-
Pastrana, John, Rabelo, Luis, Lee, Gene, Elshennawy, Ahmad, Kincaid, John, University of Central Florida
- Abstract / Description
-
INCOSE defines Model-Based Systems Engineering (MBSE) as (")the formalized application of modeling to support system requirements, design, analysis, verification, and validation activities beginning in the conceptual design phase and continuing throughout development and later life cycle phases.(") One very important development is the utilization of MBSE to develop distributed and hybrid (discrete-continuous) simulation modeling systems. MBSE can help to describe the systems to be modeled...
Show moreINCOSE defines Model-Based Systems Engineering (MBSE) as (")the formalized application of modeling to support system requirements, design, analysis, verification, and validation activities beginning in the conceptual design phase and continuing throughout development and later life cycle phases.(") One very important development is the utilization of MBSE to develop distributed and hybrid (discrete-continuous) simulation modeling systems. MBSE can help to describe the systems to be modeled and help make the right decisions and partitions to tame complexity. The ability to embrace conceptual modeling and interoperability techniques during systems specification and design presents a great advantage in distributed and hybrid simulation systems development efforts. Our research is aimed at the definition of a methodological framework that uses MBSE languages, methods and tools for the development of these simulation systems. A model-based composition approach is defined at the initial steps to identify distributed systems interoperability requirements and hybrid simulation systems characteristics. Guidelines are developed to adopt simulation interoperability standards and conceptual modeling techniques using MBSE methods and tools. Domain specific system complexity and behavior can be captured with model-based approaches during the system architecture and functional design requirements definition. MBSE can allow simulation engineers to formally model different aspects of a problem ranging from architectures to corresponding behavioral analysis, to functional decompositions and user requirements (Jobe, 2008).
Show less - Date Issued
- 2014
- Identifier
- CFE0005395, ucf:50464
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005395
- Title
- HEALTHCARE INFORMATION SYSTEMS:DESIGN THEORY, PRINCIPLES AND APPLICATION.
- Creator
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Richardson, Sandra, Courtney, James, University of Central Florida
- Abstract / Description
-
Healthcare information systems (HISs), as a class of systems, are not currently addressed in the MIS literature. This is in spite of a sharp increase in use over the past few years, and the uniquely qualified role that MIS has in the development of, impact and general understanding of HISs. In this project the design science paradigm frames the development of a set of design principles derived from the synthesis of the design literature, ethics literature, and professional guidelines, from...
Show moreHealthcare information systems (HISs), as a class of systems, are not currently addressed in the MIS literature. This is in spite of a sharp increase in use over the past few years, and the uniquely qualified role that MIS has in the development of, impact and general understanding of HISs. In this project the design science paradigm frames the development of a set of design principles derived from the synthesis of the design literature, ethics literature, and professional guidelines, from both the medical and computing professions. The resulting principles are offered to address the design of healthcare information systems. Action research, a widely accepted methodology for testing design principles derived from the design science paradigm, is employed to test the HIS principles and to implement change in a healthcare organization through the use of an HIS. The action research project was a collaborative effort between a Central Florida hospice and the researcher, the result of which was an advanced directives decision support system. The system was design to meet a number of organizational goals that ranged from tracking compliance with federal regulations to increasing the autonomy of the patients that used the system. The result is a set of tested design principles and lessons learned from both anticipated and unanticipated consequences of the action research project.
Show less - Date Issued
- 2006
- Identifier
- CFE0001339, ucf:46960
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001339
- Title
- Factory work as it is and might be: A series of four papers.
- Creator
-
Morris, William
- Date Issued
- 1922
- Identifier
- 357438, CFDT357438, ucf:5185
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/FCLA/DT/357438
- Title
- ULTRAWIDEBAND INDOOR LOCATION AND TRACKING SYSTEM.
- Creator
-
Chen, Qing, Turgut, Damla, University of Central Florida
- Abstract / Description
-
The objective of this thesis is to demonstrate an indoor intruder location and tracking system with UltraWideBand (UWB) technology and use data compression and Constant False Alarm Rate (CFAR) techniques to improve the performance of the location system. Reliable and accurate indoor positioning requires a local replacement for GPS systems since satellite signals are not available indoors. UWB systems are particularly suitable for indoor location systems due their inherent capabilities such as...
Show moreThe objective of this thesis is to demonstrate an indoor intruder location and tracking system with UltraWideBand (UWB) technology and use data compression and Constant False Alarm Rate (CFAR) techniques to improve the performance of the location system. Reliable and accurate indoor positioning requires a local replacement for GPS systems since satellite signals are not available indoors. UWB systems are particularly suitable for indoor location systems due their inherent capabilities such as low-power, multi-path rejection, and wide bandwidth. In our application, we are using UWB radios as a radar system for tracking targets in indoor locations. We also use Discrete Cosine Transform (DCT) to compress the UWB scan waveforms from the receivers to the main computer to conserve bandwidth. At the main computer, we use Inverse DCT to recover the original signal. The UWB intruder detection system has the indoor tracking accuracy of four inches. There are many military and commercial applications such as tracking firefighters and locating trapped people in earthquake zones, and so on. This thesis demonstrates the capability of a UWB radar system to locate and track an intruder to an accuracy of four inches in an indoor cluttered environment.
Show less - Date Issued
- 2006
- Identifier
- CFE0001233, ucf:46924
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001233
- Title
- A COMPARISON AND EVALUATIONOFCOMMON PID TUNING METHODS.
- Creator
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Youney, Justin, Haralambous, Michael, University of Central Florida
- Abstract / Description
-
The motivation behind this thesis is to consolidate and evaluate the most common Proportional Integral Derivative (PID) controller tuning techniques used in industry. These are the tuning techniques used when the plant transfer function is not known. Many of these systems are poorly tuned because such consolidated information is not easily found in one single source such as this thesis. Once one of the tuning methods are applied almost always there will be further fine tuning needed to bring...
Show moreThe motivation behind this thesis is to consolidate and evaluate the most common Proportional Integral Derivative (PID) controller tuning techniques used in industry. These are the tuning techniques used when the plant transfer function is not known. Many of these systems are poorly tuned because such consolidated information is not easily found in one single source such as this thesis. Once one of the tuning methods are applied almost always there will be further fine tuning needed to bring the system into the required design criteria. The purpose here is to find out which tuning technique will yield the lowest percent overshoot and the shortest settling time for all situations. This will give the engineer a good starting point; to minimally further adjust parameters to achieve the desired design criteria. There will also be discussion on the various algorithms used in industry. Four tuning methods will be evaluated based on their ability to control different style plants. The comparison criteria will be percent overshoot and settling time for an applied step input. The tuning methods chosen were the Ziegler-Nichols Open Loop method, the CHR method for 0% overshoot, the Ziegler-Nichols Closed Loop method, and the Rule of Thumb method. It is shown that for a second order plant with a lag and pure integration in its transfer function, the Open Loop method yielded the lowest results in terms of percent overshoot, yet the Closed Loop method had the shortest settling time. For systems of higher order than two it was shown that the CHR method gave the best performance however as the order increased the Closed Loop method gave a shorter settling time. For systems of higher order with varying lags in series the CHR method gave the best results. The Rule of thumb method usually gave similar results to that of the Closed Loop method; however for higher order systems the Rule of Thumb method gave less percent overshoot but with a longer settling time than the Closed Loop method. Since these tuning methods are used when the plant transfer function is not known, and none of the rules were found to give consistently the lowest percent overshoot, and settling time for all plants tested, there can not be a recommendation as to which method an engineer should choose to use. If the plant transfer function is known or can be reasonably modeled then the following recommendations can be followed. When tuning systems with pure integrations in their transfer function the Open Loop or Closed Loop method be used. When tuning systems of order higher than two the CHR or Closed Loop method should be used, however with high order systems with varying lags the CHR method should be used. It is the responsibility of the engineer to know how and when to implement each of the tuning rules properly.
Show less - Date Issued
- 2007
- Identifier
- CFE0001716, ucf:47301
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001716
- Title
- A CUSTOMER PROGRAMMABLE MICROFLUIDIC SYSTEM.
- Creator
-
Liu, Miao, Chen, Quanfang, University of Central Florida
- Abstract / Description
-
Microfluidics is both a science and a technology offering great and perhaps even revolutionary capabilities to impact the society in the future. However, due to the scaling effects there are unknown phenomena and technology barriers about fluidics in microchannel, material properties in microscale and interactions with fluids are still missing. A systematic investigation has been performed aiming to develop "A Customer Programmable Microfluidic System". This innovative Polydimethylsiloxane ...
Show moreMicrofluidics is both a science and a technology offering great and perhaps even revolutionary capabilities to impact the society in the future. However, due to the scaling effects there are unknown phenomena and technology barriers about fluidics in microchannel, material properties in microscale and interactions with fluids are still missing. A systematic investigation has been performed aiming to develop "A Customer Programmable Microfluidic System". This innovative Polydimethylsiloxane (PDMS)-based microfluidic system provides a bio-compatible platform for bio-analysis systems such as Lab-on-a-chip, micro-total-analysis system and biosensors as well as the applications such as micromirrors. The system consists of an array of microfluidic devices and each device containing a multilayer microvalve. The microvalve uses a thermal pneumatic actuation method to switch and/or control the fluid flow in the integrated microchannels. It provides a means to isolate samples of interest and channel them from one location of the system to another based on needs of realizing the customers' desired functions. Along with the fluid flow control properties, the system was developed and tested as an array of micromirrors. An aluminum layer is embedded into the PDMS membrane. The metal was patterned as a network to increase the reflectivity of the membrane, which inherits the deformation of the membrane as a mirror. The deformable mirror is a key element in the adaptive optics. The proposed system utilizes the extraordinary flexibility of PDMS and the addressable control to manipulate the phase of a propagating optical wave front, which in turn can increase the performance of the adaptive optics. Polydimethylsiloxane (PDMS) has been widely used in microfabrication for microfluidic systems. However, few attentions were paid in the past to mechanical properties of PDMS. Importantly there is no report on influences of microfabrication processes which normally involve chemical reactors and biologically reaction processes. A comprehensive study was made in this work to study fundamental issues such as scaling law effects on PDMS properties, chemical emersion and temperature effects on mechanical properties of PDMS, PDMS compositions and resultant properties, as well as bonding strength, etc. Results achieved from this work will provide foundation of future developments of microfluidics utilizing PDMS.
Show less - Date Issued
- 2008
- Identifier
- CFE0002372, ucf:47798
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002372
- Title
- The generation of synthetic speech sounds by digital coding.
- Creator
-
Steinberger, Eddy Alan, null, null, Engineering
- Abstract / Description
-
FLorida Technological University College of Engineering Thesis; The feasibility of representing human speech by serial digital codes was investigated by exercising specially constructed digital logic coupled with standard audio output equipment. The theories being tested represent a radical departure from previous efforts in the field of speech research. Therefore, this initial investigation was limited in scope to a study of unconnected English language speech sounds at the phenome level.
- Date Issued
- 1975
- Identifier
- CFR0002823, ucf:52917
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0002823
- Title
- Torque-speed Linearization of a D.C. Servo System.
- Creator
-
Mantello, Nicholas A., Simons Jr., Fred. O., Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis; In early 1973 Professor Fred O. Simons Jr., of Florida Technological University, suggested the topic for this research report. During control engineering discussions, it was proposed that a D.C. Shunt Motor could be constrained to perform in an idealized sense for the static case. The purposed of this report is to provide a reasonably comprehensive examination of a control which linearizes the torque-speed relationship of a dc...
Show moreFlorida Technological University College of Engineering Thesis; In early 1973 Professor Fred O. Simons Jr., of Florida Technological University, suggested the topic for this research report. During control engineering discussions, it was proposed that a D.C. Shunt Motor could be constrained to perform in an idealized sense for the static case. The purposed of this report is to provide a reasonably comprehensive examination of a control which linearizes the torque-speed relationship of a dc servo system. The fundamental goal is to determine a control which linearizes the torque-speed output relation of a system, in which a dc shunt motor is under basic armature control. Consequently, the emphasis is on a concept and technique rather than the design of the system process. In this regard, the report does not delve into performance analysis, or design of the system to constrain the torque and speed parameters to operate along an idealized curve.
Show less - Date Issued
- 1976
- Identifier
- CFR0011992, ucf:53092
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0011992
- Title
- A survey of weapon system cost effectiveness methodologies.
- Creator
-
Fritz, John T., null, null, Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis; A survey of cost effectiveness methodologies used in the defense industry is presented and an application of cost effectiveness is developed. A breakdown in the level of the decision making is made and follows the example of the Weapon System Effectiveness Industry Advisory Committee. Examples of cost effectiveness methodologies at each decision making level are shown.
- Date Issued
- 1976
- Identifier
- CFR0003499, ucf:53008
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0003499
- Title
- A Simulation Analysis of Traffic Congestion in Telephone Systems.
- Creator
-
Duncan, Raymond B., Clapp, Donald E., Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis
- Date Issued
- 1975
- Identifier
- CFR0011991, ucf:53099
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0011991
- Title
- High resolution time-resolved imaging system in the vacuum ultraviolet region.
- Creator
-
Jang, Yuseong, Richardson, Martin, Moharam, Jim, Likamwa, Patrick, University of Central Florida
- Abstract / Description
-
High-power debris-free vacuum ultraviolet (VUV) light sources have applications in several scientific and engineering areas, such as high volume manufacturing lithography and inspection tools in the semiconductor industry, as well as other applications in material processing and photochemistry.For the past decades, the semiconductor industry has been driven by what is called "Moore's Law". The entire semiconductor industry relies on this rule, which requires chip makers to pack transistors...
Show moreHigh-power debris-free vacuum ultraviolet (VUV) light sources have applications in several scientific and engineering areas, such as high volume manufacturing lithography and inspection tools in the semiconductor industry, as well as other applications in material processing and photochemistry.For the past decades, the semiconductor industry has been driven by what is called "Moore's Law". The entire semiconductor industry relies on this rule, which requires chip makers to pack transistors more tightly with every new generation of chips, shrinking the size of transistors. The ability to solve roadmap challenges is, at least partly, proportional to our ability to measure them. The focus of this thesis is on imaging transient VUV laser plasma sources with specialized reflective imaging optics for metrology applications. The plasma dynamics in novel laser-based Zinc and Tin plasma sources will be discussed. The Schwarzschild optical system was installed to investigate the time evolution of the plasma size in the VUV region at wavelengths of 172 nm and 194 nm. The outcomes are valuable for interpreting the dynamics of low-temperature plasma and to optimize laser-based VUV light sources.
Show less - Date Issued
- 2014
- Identifier
- CFE0005352, ucf:50492
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005352
- Title
- EXPLANATIONS IN CONTEXTUAL GRAPHS:A SOLUTION TO ACCOUNTABILITY INKNOWLEDGE BASED SYSTEMS.
- Creator
-
Sherwell, Brian, Gonzalez, Avelino, University of Central Florida
- Abstract / Description
-
In order for intelligent systems to be a viable and utilized tool, a user must be able to understand how the system comes to a decision. Without understanding how the system arrived at an answer, a user will be less likely to trust its decision. One way to increase a user's understanding of how the system functions is by employing explanations to account for the output produced. There have been attempts to explain intelligent systems over the past three decades. However, each attempt has had...
Show moreIn order for intelligent systems to be a viable and utilized tool, a user must be able to understand how the system comes to a decision. Without understanding how the system arrived at an answer, a user will be less likely to trust its decision. One way to increase a user's understanding of how the system functions is by employing explanations to account for the output produced. There have been attempts to explain intelligent systems over the past three decades. However, each attempt has had shortcomings that separated the logic used to produce the output and that used to produce the explanation. By using the representational paradigm of Contextual Graphs, it is proposed that explanations can be produced to overcome these shortcomings. Two different temporal forms of explanations are proposed, a pre-explanation and a post-explanation. The pre-explanation is intended to help the user understand the decision making process. The post-explanation is intended to help the user understand how the system arrived at a final decision. Both explanations are intended to help the user gain a greater understanding of the logic used to compute the system's output, and thereby enhance the system's credibility and utility. A prototype system is constructed to be used as a decision support tool in a National Science Foundation research program. The researcher has spent the last year at the NSF collecting the knowledge implemented in the prototype system.
Show less - Date Issued
- 2005
- Identifier
- CFE0000713, ucf:46601
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000713
- Title
- A HYBRID SYSTEM DYNAMICS-DISCRETE EVENT SIMULATIONAPPROACH TO SIMULATING THE MANUFACTURING ENTERPRISE.
- Creator
-
Helal, Magdy, Rabelo, Luis, University of Central Florida
- Abstract / Description
-
With the advances in the information and computing technologies, the ways the manufacturing enterprise systems are being managed are changing. More integration and adoption of the system perspective push further towards a more flattened enterprise. This, in addition to the varying levels of aggregation and details and the presence of the continuous and discrete types of behavior, created serious challenges for the use of the existing simulation tools for simulating the modern manufacturing...
Show moreWith the advances in the information and computing technologies, the ways the manufacturing enterprise systems are being managed are changing. More integration and adoption of the system perspective push further towards a more flattened enterprise. This, in addition to the varying levels of aggregation and details and the presence of the continuous and discrete types of behavior, created serious challenges for the use of the existing simulation tools for simulating the modern manufacturing enterprise system. The commonly used discrete event simulation (DES) techniques face difficulties in modeling such integrated systems due to increased model complexity, the lack of data at the aggregate management levels, and the unsuitability of DES to model the financial sectors of the enterprise. System dynamics (SD) has been effective in providing the needs of top management levels but unsuccessful in offering the needed granularity at the detailed operational levels of the manufacturing system. On the other hand the existing hybrid continuous-discrete tools are based on certain assumptions that do not fit the requirements of the common decision making situations in the business systems. This research has identified a need for new simulation modeling approaches that responds to the changing business environments towards more integration and flattened enterprise systems. These tools should be able to develop comprehensive models that are inexpensive, scalable, and able to accommodate the continuous and discrete modes of behavior, the stochastic and deterministic natures of the various business units, and the detail complexity and dynamic complexity perspectives in decision making. The research proposes and develops a framework to combine and synchronize the SD and DES simulation paradigms to simulate the manufacturing enterprise system. The new approach can respond to the identified requirements in simulating the modern manufacturing enterprise systems. It is directed toward building comprehensive simulation models that can accommodate all management levels while explicitly recognizing the differences between them in terms of scope and frequency of decision making as well as the levels of details preferred and used at each level. This SDDES framework maintains the integrity of the two simulation paradigms and can use existing/legacy simulation models without requiring learning new simulation or computer programming skills. The new framework uses a modular structure by which the SD and DES models are treated as members of a comprehensive simulation. A new synchronization mechanism that that maintains the integrity of the two simulation paradigms and is not event-driven is utilized to coordinate the interactions between the simulation modules. It avoids having one simulation paradigm dominating the other. For communication and model management purposes the SDDES formalism provides a generic format to describe, specify, and document the simulation modules and the information sharing processes. The SDDES controller which is the communication manager, implements the synchronization mechanism and manages the simulation run ensuring correct exchange of data in terms of timeliness and format, between the modules. It also offers the user interface through which users interact with the simulation modules.
Show less - Date Issued
- 2008
- Identifier
- CFE0002264, ucf:47835
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002264
- Title
- Development of Decision Support System for Active Traffic Management Systems Considering Travel Time Reliability.
- Creator
-
Chung, Whoibin, Abdel-Aty, Mohamed, Eluru, Naveen, Hasan, Samiul, Cai, Qing, Huang, Hsin-Hsiung, University of Central Florida
- Abstract / Description
-
As traffic problems on roadways have been increasing, active traffic management systems (ATM) using proactive traffic management concept have been deployed on freeways and arterials. The ATM aims to integrate and automate various traffic control strategies such as variable speed limits, queue warning, and ramp metering through a decision support system (DSS). Over the past decade, there have been many efforts to integrate freeways and arterials for the efficient operation of roadway networks....
Show moreAs traffic problems on roadways have been increasing, active traffic management systems (ATM) using proactive traffic management concept have been deployed on freeways and arterials. The ATM aims to integrate and automate various traffic control strategies such as variable speed limits, queue warning, and ramp metering through a decision support system (DSS). Over the past decade, there have been many efforts to integrate freeways and arterials for the efficient operation of roadway networks. It has been required that these systems should prove their effectiveness in terms of travel time reliability. Therefore, this study aims to develop a new concept of a decision support system integrating variable speed limits, queue warning, and ramp metering on the basis of travel time reliability of freeways and arterials.Regarding the data preparation, in addition to collecting multiple data sources such as traffic data, crash data and so on, the types of traffic data sources that can be applied for the analysis of travel time reliability were investigated. Although there are many kinds of real-time traffic data from third-party traffic data providers, it was confirmed that these data cannot represent true travel time reliability through the comparative analysis of measures of travel time reliability. Related to weather data, it was proven that nationwide land-based weather stations could be applicable.Since travel time reliability can be measured by using long-term periods for more than six months, it is necessary to develop models to estimate travel time reliability through real-time traffic data and event-related data. Among various matrix to measure travel time reliability, the standard deviation of travel time rate [minute/mile] representing travel time variability was chosen because it can represent travel time variability of both link and network level. Several models were developed to estimate the standard deviation of travel time rate through average travel time rate, the number of lanes, speed limits, and the amount of rainfall.Finally, a DSS using a model predictive control method to integrate multiple traffic control measures was developed and evaluated. As a representative model predictive control, METANET model was chosen, which can include variable speed limit, queue warning, and ramp metering, separately or combined. The developed DSS identified a proper response plan by comparing travel time reliability among multiple combinations of current and new response values of strategies. In the end, it was found that the DSS provided the reduction of travel time and improvement of its reliability for travelers through the recommended response plans.
Show less - Date Issued
- 2019
- Identifier
- CFE0007615, ucf:52542
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007615
- Title
- Development of a Cognitive Work Analysis Framework Tutorial Using Systems Modeling Language.
- Creator
-
Wells, Wilfred, Karwowski, Waldemar, Williams, Kent, Sala-Diakanda, Serge, Elshennawy, Ahmad, Ahram, Tareq, University of Central Florida
- Abstract / Description
-
At the present time, most systems engineers do not have access to cognitivework analysis information or training in terms they can understand. This may lead to adisregard of the cognitive aspect of system design. The impact of this issue is systemrequirements that do not account for the cognitive strengths and limitations of users.Systems engineers cannot design effective decision support systems without definingcognitive work requirements. In order to improve system requirements, integration...
Show moreAt the present time, most systems engineers do not have access to cognitivework analysis information or training in terms they can understand. This may lead to adisregard of the cognitive aspect of system design. The impact of this issue is systemrequirements that do not account for the cognitive strengths and limitations of users.Systems engineers cannot design effective decision support systems without definingcognitive work requirements. In order to improve system requirements, integration ofcognitive work requirements into the systems engineering process has to be improved.One option to address this gap is the development of a Cognitive Work Analysis (CWA)framework using Systems Modeling Language (SysML). The study had two phases.The first involved aligning the CWA terminology with the SysML to produce a CWAframework using SysML. The second was the creation of an instruction using SysML toinform systems engineers of the process of integrating cognitive work requirements intothe systems engineering process. This methodology provides a structured framework todefine, manage, organize, and model cognitive work requirements. Additionally, itprovides a tool for systems engineers to use in system design which supports a user'scognitive functions, such as situational awareness, problem solving, and decisionmaking.
Show less - Date Issued
- 2011
- Identifier
- CFE0004177, ucf:49079
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004177
- Title
- ROBUST DIALOG MANAGEMENT THROUGH A CONTEXT-CENTRIC ARCHITECTURE.
- Creator
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Hung, Victor, Gonzalez, Avelino, University of Central Florida
- Abstract / Description
-
This dissertation presents and evaluates a method of managing spoken dialog interactions with a robust attention to fulfilling the human user's goals in the presence of speech recognition limitations. Assistive speech-based embodied conversation agents are computer-based entities that interact with humans to help accomplish a certain task or communicate information via spoken input and output. A challenging aspect of this task involves open dialog, where the user is free to converse in an...
Show moreThis dissertation presents and evaluates a method of managing spoken dialog interactions with a robust attention to fulfilling the human user's goals in the presence of speech recognition limitations. Assistive speech-based embodied conversation agents are computer-based entities that interact with humans to help accomplish a certain task or communicate information via spoken input and output. A challenging aspect of this task involves open dialog, where the user is free to converse in an unstructured manner. With this style of input, the machine's ability to communicate may be hindered by poor reception of utterances, caused by a user's inadequate command of a language and/or faults in the speech recognition facilities. Since a speech-based input is emphasized, this endeavor involves the fundamental issues associated with natural language processing, automatic speech recognition and dialog system design. Driven by Context-Based Reasoning, the presented dialog manager features a discourse model that implements mixed-initiative conversation with a focus on the user's assistive needs. The discourse behavior must maintain a sense of generality, where the assistive nature of the system remains constant regardless of its knowledge corpus. The dialog manager was encapsulated into a speech-based embodied conversation agent platform for prototyping and testing purposes. A battery of user trials was performed on this agent to evaluate its performance as a robust, domain-independent, speech-based interaction entity capable of satisfying the needs of its users.
Show less - Date Issued
- 2010
- Identifier
- CFE0003230, ucf:48556
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003230
- Title
- Critical Success Factors for Evolutionary Acquisition Implementation.
- Creator
-
Bjorn, Brig, Kotnour, Timothy, Karwowski, Waldemar, Mollaghasemi, Mansooreh, Farr, John, University of Central Florida
- Abstract / Description
-
Due to extensive challenges to the efficient development and fielding of operationally effective and affordable weapon systems, the U.S. employs a complex management framework to govern defense acquisition programs. The Department of Defense and Congress recently modified this process to improve the levels of knowledge available at key decision points in order to reduce lifecycle cost, schedule, and technical risk to programs. This exploratory research study employed multiple methods to...
Show moreDue to extensive challenges to the efficient development and fielding of operationally effective and affordable weapon systems, the U.S. employs a complex management framework to govern defense acquisition programs. The Department of Defense and Congress recently modified this process to improve the levels of knowledge available at key decision points in order to reduce lifecycle cost, schedule, and technical risk to programs. This exploratory research study employed multiple methods to examine the impact of systems engineering reviews, competitive prototyping, and the application of a Modular Open Systems Approach on knowledge and risk prior to funding system implementation and production. In-depth case studies of two recent Major Defense Acquisition Programs were conducted to verify the existence and relationships of the proposed constructs and identify potential barriers to program success introduced by the new process. The case studies included program documentation analysis as well as interviews with contractor personnel holding multiple roles on the program. A questionnaire-based survey of contractor personnel from a larger set of programs was executed to test the case study findings against a larger data set. The study results indicate that while some changes adversely affected program risk levels, the recent modifications to the acquisition process generally had a positive impact on levels of critical knowledge at the key Milestone B decision point. Based on the results of this study it is recommended that the Government improve its ability to communicate with contractors during competitive phases, particularly with regard to requirements management, and establish verifiable criteria for compliance with theModular Open Systems Approach. Additionally, the Government should clarify the intent of competitive prototyping and develop a strategy to better manage the inevitable gaps between program phases. Contractors are recommended to present more requirements trade-offs and focus less on prototype development during the Technology Development phases of programs. The results of this study may be used by policy makers to shape future acquisition reforms; by Government personnel to improve the implementation of the current regulations; and by contractors to shape strategies and processes for more effective system development. This research may be used by the Government to improve the execution of acquisition programs under this new paradigm. The defense industrial base can use this research to better understand the impacts of the new process and improve strategic planning processes. The research methodology may be applied to new and different types of programs to assess improvement in the execution process over time.
Show less - Date Issued
- 2012
- Identifier
- CFE0004358, ucf:49442
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004358
- Title
- COGNITIVE LEARNING FROM COMPUTER-BASED INFORMATION SYSTEMS BY INCORPORATING KNOWLEDGE CONSTRUCTION INTERVENTIONS.
- Creator
-
Wazzan, Wajdi, Williams, Kent, University of Central Florida
- Abstract / Description
-
The aim of the present study was to develop and empirically evaluate different categories of instructional activities, which stimulate the generation and construction of knowledge on the part of an individual student. These generative activities are primed by prompts or scaffolds, which can easily be inserted into specific curriculum addressing any domain of knowledge. To assess the manner in which the knowledge construction interventions influence the learning outcomes from computerized...
Show moreThe aim of the present study was to develop and empirically evaluate different categories of instructional activities, which stimulate the generation and construction of knowledge on the part of an individual student. These generative activities are primed by prompts or scaffolds, which can easily be inserted into specific curriculum addressing any domain of knowledge. To assess the manner in which the knowledge construction interventions influence the learning outcomes from computerized information systems, we have developed an online computer-based information system that describes the functions and mechanisms associated with the bus system of the US army Abrams M1A2 tank. Seven versions of this interactive instructional computer system were developed for this research; the type of prompt was manipulated among the seven experimental conditions. The seven experimental conditions were control, sentence completion, sentence generation, system provided questions, self-generated questions and answers, system provided advanced organizers, and generated advanced organizers. The results from this study provided strong evidence that the integration of knowledge construction interventions within the curriculum material have improved understanding of the curriculum content and reasoning about such content over and above the mere presentation and study of the curriculum. The research also delineated a practical way on how to incorporate and operationally integrate the knowledge construction interventions within computer-based information systems.
Show less - Date Issued
- 2007
- Identifier
- CFE0001696, ucf:47202
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001696
