Current Search: Simulation (x)
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- Title
- TRAFFIC CONFLICT ANALYSIS UNDER FOG CONDITIONS USING COMPUTER SIMULATION.
- Creator
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Zhang, Binya, Radwan, Essam, Abdel-Aty, Mohamed, Abou-Senna, Hatem, University of Central Florida
- Abstract / Description
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The weather condition is a crucial influence factor on road safety issues. Fog is one of the most noticeable weather conditions, which has a significant impact on traffic safety. Such condition reduces the road's visibility and consequently can affect drivers' vision, perception, and judgments. The statistical data shows that many crashes are directly or indirectly caused by the low-visibility weather condition. Hence, it is necessary for road traffic engineers to study the relationship of...
Show moreThe weather condition is a crucial influence factor on road safety issues. Fog is one of the most noticeable weather conditions, which has a significant impact on traffic safety. Such condition reduces the road's visibility and consequently can affect drivers' vision, perception, and judgments. The statistical data shows that many crashes are directly or indirectly caused by the low-visibility weather condition. Hence, it is necessary for road traffic engineers to study the relationship of road traffic accidents and their influence factors. Among these factors, the traffic volume and the speed limits in poor visibility areas are the primary reasons that can affect the types and occurring locations of road accidents.In this thesis, microscopic traffic simulation, through the use of VISSIM software, was used to study the road safety issue and its influencing factors due to limited visibility. A basic simulation model was built based on previously collected field data to simulate Interstate 4 (I-4)'s environment, geometry characteristics, and the basic traffic volume composition conditions. On the foundation of the basic simulation model, an experimental model was built to study the conflicts' types and distribution places under several different scenarios. Taking into consideration the entire 4-mile study area on I-4, this area was divided into 3 segments: section 1 with clear visibility, fog area of low visibility, and section 2 with clear visibility. Lower speed limits in the fog area, which were less than the limits in no-fog areas, were set to investigate the different speed limits' influence on the two main types of traffic conflicts: lane-change conflicts and rear-end conflicts. The experimental model generated several groups of traffic trajectory data files. The vehicle conflicts data were stored in these trajectory data files which, contains the conflict locations' coordinates, conflict time, time-to-conflict, and post-encroachment-time among other measures. The Surrogate Safety Assessment Model (SSAM), developed by the Federal Highway Administration, was applied to analyze these conflict data.From the analysis results, it is found that the traffic volume is an important factor, which has a large effect on the number of conflicts. The number of lane-change and rear-end conflicts increases along with the traffic volume growth. Another finding is that the difference between the speed limits in the fog area and in the no-fog areas is another significant factor that impacts the conflicts' frequency. Larger difference between the speed limits in two nearing road sections always leads to more accidents due to the inadequate reaction time for vehicle drivers to brake in time. And comparing to the scenarios that with the reduced speed limits in the low visibility zone, the condition that without the reduced speed limit has higher conflict number, which indicates that the it is necessary to put a lower speed limit in the fog zone which has a lower visibility. The results of this research have a certain reference value for studying the relationship between the road traffic conflicts and the impacts of different speed limits under fog condition. Overall, the findings of this research suggest follow up studies to further investigate possible relationships between conflicts as observed by simulation models and reported crashes in fog areas.
Show less - Date Issued
- 2015
- Identifier
- CFE0005747, ucf:50104
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005747
- Title
- THE CALIBRATION AND VERIFICATION OF SIMULATION MODELS FOR TOLL PLAZAS.
- Creator
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Russo, Christopher, Radwan, Essam, University of Central Florida
- Abstract / Description
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A great deal of research has been conducted on Central Florida toll roads to better understand the characteristics of the tolling operation. In this thesis, the development and calibration of a toll plaza simulation models will be analyzed using two simulation programs varying mostly in their modeling theory. The two models utilized are, SHAKER, a deterministic queuing model for vehicles utilizing toll collection facilities, and VISSIM, a globally popular stochastic simulation software. The...
Show moreA great deal of research has been conducted on Central Florida toll roads to better understand the characteristics of the tolling operation. In this thesis, the development and calibration of a toll plaza simulation models will be analyzed using two simulation programs varying mostly in their modeling theory. The two models utilized are, SHAKER, a deterministic queuing model for vehicles utilizing toll collection facilities, and VISSIM, a globally popular stochastic simulation software. The benefits of simulation models leads to the purpose of this thesis, which is to examine the effectiveness of two toll modeling programs that are similar in purpose but vary in approach and methodology. Both SHAKER and VISSIM toll plaza models have the potential to work as a tool that can estimate the maximum throughput and capacity of toll plazas. Major operational benefits resulting from developing these models are to simulate and evaluate how traffic conditions will change when demand increases, when and if queues increase when a lane is closed due to maintenance or construction, the impact of constructing additional lanes, or determining whether or not the best lane type configuration is currently implemented. To effectively calibrate any model available site data must be used to compare simulation results to for model validity. In an effort to correctly calibrate the SHAKER toll plaza tool and VISSIM model, an extensive field collection procedure was conducted at four Florida Turnpike operated toll facilities located in Central Florida. Each site differed from the others in terms of number of lanes, lane configuration, toll base fee, highway location, traffic demand, and vehicle percentage. The sites chosen for data collection were: the Lake Jesup Mainline Plaza along the Seminole Expressway (SR-417), the Beachline West Expressway Toll Plaza along the SR-528, the Daniel Webster Western Beltway Plaza along SR-429, and the Leesburg Toll Plaza along the Florida Turnpike Mainline SR-91. Upon completion of calibration of the two simulation models it is determined that each of the two software are successful in modeling toll plaza capacity and queuing. As expected, each simulation model does possess benefits over the other in terms of set up time, analysis reporting time, and practicality of results. The SHAKER model setup takes mere seconds in order to create a network and input vehicle, another few seconds to calibrate driving parameters, and roughly 10 additional seconds to report analysis. Conversely, setting up the VISSIM model, even for the most experienced user, can take several hours and the report analysis time can take several more hours as it is dependant on the number of required simulation runs and complexity of the network. VISSIM is most beneficial by the fact that its modeling allows for driver variability while SHAKER assumes equilibrium amongst lane choice and queuing. This creates a more realistic condition to observed traffic patterns. Even though differences are prevalent, it is important that in each simulation model the capacity is accurately simulated and each can be used to benefit operational situations related to toll plaza traffic conditions.
Show less - Date Issued
- 2008
- Identifier
- CFE0002376, ucf:47821
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002376
- Title
- AUTOMATIC GENERATION OF SUPPLY CHAIN SIMULATION MODELS FROM SCOR BASED ONTOLOGIES.
- Creator
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Cope, Dayana, Sepulveda, Jose, University of Central Florida
- Abstract / Description
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In today's economy of global markets, supply chain networks, supplier/customer relationship management and intense competition; decision makers are faced with a need to perform decision making using tools that do not accommodate the nature of the changing market. This research focuses on developing a methodology that addresses this need. The developed methodology provides supply chain decision makers with a tool to perform efficient decision making in stochastic, dynamic and distributed...
Show moreIn today's economy of global markets, supply chain networks, supplier/customer relationship management and intense competition; decision makers are faced with a need to perform decision making using tools that do not accommodate the nature of the changing market. This research focuses on developing a methodology that addresses this need. The developed methodology provides supply chain decision makers with a tool to perform efficient decision making in stochastic, dynamic and distributed supply chain environments. The integrated methodology allows for informed decision making in a fast, sharable and easy to use format. The methodology was implemented by developing a stand alone tool that allows users to define a supply chain simulation model using SCOR based ontologies. The ontology includes the supply chain knowledge and the knowledge required to build a simulation model of the supply chain system. A simulation model is generated automatically from the ontology to provide the flexibility to model at various levels of details changing the model structure on the fly. The methodology implementation is demonstrated and evaluated through a retail oriented case study. When comparing the implementation using the developed methodology vs. a "traditional" simulation methodology approach, a significant reduction in definition and execution time was observed.
Show less - Date Issued
- 2008
- Identifier
- CFE0002009, ucf:47625
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002009
- Title
- Exploration of the Impact of Affective Variables on Human Performance in a Live Simulation.
- Creator
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Westerlund, Ken, Kincaid, John, Sims, Valerie, Chin, Matthew, VanderVeen, Cornelius, University of Central Florida
- Abstract / Description
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Live simulations play an important role in allowing users to practice and develop skills they learn in training. Although live simulations are playing an increasingly important role in training, ways to improve them are not well understood or documented. In order to improve the efficacy of live simulation and maximize results from funds spent on training; this research examines the relationship between the affective variables of the participants and their performance in the live simulation....
Show moreLive simulations play an important role in allowing users to practice and develop skills they learn in training. Although live simulations are playing an increasingly important role in training, ways to improve them are not well understood or documented. In order to improve the efficacy of live simulation and maximize results from funds spent on training; this research examines the relationship between the affective variables of the participants and their performance in the live simulation. Prior to participating in the instructor development live simulation used in this study two training preference scales were administered to a group of trainees. These scales measured the trainees' locus of control and immersion tendencies. During the live simulation the trainees' performance was evaluated by a panel of expert observers. The trainees also self-reported their performance through the use of a self-rating instrument. Analysis of the data revealed significant positive correlations between the trainees' internal locus of control and their performance in the simulation, both self-reported (p=0.026) and as reported by the expert observers (p=0.033). The correlation between immersion tendency scores and performance in the live simulation were mixed; while not always statistically significant they did reveal some slight positive correlation. This research did provide a number of lessons learned and implications for instructional and simulation developers wishing to employ live simulation in a training environment. These include performance of sub-populations within the greater population of subjects, consideration of roles assigned to participants, and the need to increase presence within the live simulation. Application of these lessons learned can reduce training costs and/or improve the effectiveness of live simulation in a training environment, this in turn can be of significant benefit to instructional and simulation designers. Additionally, understanding these relationships can lead to better assignments of roles or activities within live simulation and improve the transfer of experience from live simulation training to on the job performance. However, additional research needs to be conducted in order to make more conclusive statements regarding the most appropriate affective variable that would allow for predicting transfer of the simulated experience to the 'real' world, the individuals who would benefit most from live simulation, and to develop additional prescriptive methods for improving live simulation utilized in training environments.
Show less - Date Issued
- 2013
- Identifier
- CFE0004958, ucf:49578
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004958
- Title
- Translocation of a semiflexible polymer through a nanopore.
- Creator
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Adhikari, Ramesh, Bhattacharya, Aniket, Chen, Bo, Kokoouline, Viatcheslav, Hernandez, Florencio, University of Central Florida
- Abstract / Description
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The transport of a biomolecule through a nanopore occurs in many biological functions such as, DNA or RNA transport across nuclear pores and the translocation of proteins across the eukaryotic endoplasmic reticulum. In addition to the biological processes, it has potential applications in technology such as, drug delivery, gene therapy, and single molecule sensing. The DNA translocation through a synthetic nanopore device is considered as the basis for cheap and fast sequencing technology....
Show moreThe transport of a biomolecule through a nanopore occurs in many biological functions such as, DNA or RNA transport across nuclear pores and the translocation of proteins across the eukaryotic endoplasmic reticulum. In addition to the biological processes, it has potential applications in technology such as, drug delivery, gene therapy, and single molecule sensing. The DNA translocation through a synthetic nanopore device is considered as the basis for cheap and fast sequencing technology. Motivated by the experimental advances, many theoretical models have been developed. In this thesis, we explore the dynamics of driven translocation of a semiflexible polymer through a nanopore in two dimensions (2D) using Langevin dynamics (LD) simulation. By carrying out extensive simulation as a function of different parameters such as, driving force, length and rigidity of the chain, viscosity of the solvent, and diameter of the nanopore, we provide a detailed description of the translocation process. Our studies are relevant for fundamental understanding of the translocation process which is essential for making accurate nano-pore based devices.
Show less - Date Issued
- 2015
- Identifier
- CFE0005915, ucf:50830
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005915
- Title
- Integrated Maritime Simulation Complex Management, Quality And Training Effectiveness From The Perspective Of Modeling And Simulation In The State Of Florida, USA (A Case Study).
- Creator
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Sendi, Yaser, Kincaid, John, Rabelo, Luis, Lee, Gene, University of Central Florida
- Abstract / Description
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Naturally, maritime training simulators at all events are valuable instructional and pedagogical tools. Through the history, the maritime simulation was utilized to train prospective maritime apprentices in whom it has filled the gap left by the acute shortage of opportunities for jobs onboard vessels around the globe. However, professional seafarers are the axis of success and competitiveness in the field of maritime training. They are the ones that, who are well trained and have the...
Show moreNaturally, maritime training simulators at all events are valuable instructional and pedagogical tools. Through the history, the maritime simulation was utilized to train prospective maritime apprentices in whom it has filled the gap left by the acute shortage of opportunities for jobs onboard vessels around the globe. However, professional seafarers are the axis of success and competitiveness in the field of maritime training. They are the ones that, who are well trained and have the responsibilities of their work and the surrounding environment. In order to achieve the success along with effective training skills, both maritime companies and seafarers should implement a management of safety onboard ships, which only can be executed through the effective usage of the Bridge Resource Management (BRM) and righteous maritime simulation training.Qualitative upgrading of the maritime training process at higher education levels depends predominantly on the instructive value of the instructors' educational software and the content of these programs which contains advanced and intelligent scenarios that benefit positively in providing effective training in order to, transfer and implement their gained skills from virtual reality to the actual environment with minimal risks and additionally to avoid the unforeseen occurrences at sea. The outcomes of the evaluation have shown the instructional suitability of the maritime educational scheme and significant capabilities, it provides, as well as the domains and frameworks for its instructional development. The above facts are substantial in the refinement and improvement of the current maritime education and growth of the apprentices' capabilities and the professionalism of their skills, along with the farthest purpose of creating more educated marine navigators in the worldwide merchant fleet.This research proposes and demonstrates in details the purpose of the maritime simulation training complexes, the elements that if provided, will lead to an effective maritime simulation training, types of maritime simulation, the International Maritime Organization (IMO), its tools and its power for the effectiveness of the maritime simulation training through different conventions (&) codes and the future for the maritime simulation training, in order to emphasize and accentuate the interplay between instructors and apprentices in an integrated maritime simulation complex on which a serious maritime event is taking place.The distillation of this thesis draws an attention to the effectiveness of the partnership between maritime apprentices and their instructors across a maritime simulation training complex scheme during a virtual maritime scenario event in an advanced facilities located in the state of Florida, which is armed with modern technology, provides both added stimulation for the apprentice himself and elevates the simulator a degree toward a vessel for practical training and/or sailing.
Show less - Date Issued
- 2015
- Identifier
- CFE0005999, ucf:50787
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005999
- Title
- A Hybrid Simulation Framework of Consumer-to-Consumer Ecommerce Space.
- Creator
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Joledo, Oloruntomi, Rabelo, Luis, Lee, Gene, Elshennawy, Ahmad, Ajayi, Richard, University of Central Florida
- Abstract / Description
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In the past decade, ecommerce transformed the business models of many organizations. Information Technology leveled the playing field for new participants, who were capable of causing disruptive changes in every industry. (")Web 2.0(") or (")Social Web(") further redefined ways users enlist for services. It is now easy to be influenced to make choices of services based on recommendations of friends and popularity amongst peers. This research proposes a simulation framework to investigate how...
Show moreIn the past decade, ecommerce transformed the business models of many organizations. Information Technology leveled the playing field for new participants, who were capable of causing disruptive changes in every industry. (")Web 2.0(") or (")Social Web(") further redefined ways users enlist for services. It is now easy to be influenced to make choices of services based on recommendations of friends and popularity amongst peers. This research proposes a simulation framework to investigate how actions of stakeholders at this level of complexity affect system performance as well as the dynamics that exist between different models using concepts from the fields of operations engineering, engineering management, and multi-model simulation. Viewing this complex model from a systems perspective calls for the integration of different levels of behaviors. Complex interactions exist among stakeholders, the environment and available technology. The presence of continuous and discrete behaviors coupled with stochastic and deterministic behaviors present challenges for using standalone simulation tools to simulate the business model.We propose a framework that takes into account dynamic system complexity and risk from a hybrid paradigm. The SCOR model is employed to map the business processes and it is implemented using agent based simulation and system dynamics. By combining system dynamics at the strategy level with agent based models of consumer behaviors, an accurate yet efficient representation of the business model that makes for sound basis of decision making can be achieved to maximize stakeholders' utility.
Show less - Date Issued
- 2016
- Identifier
- CFE0006122, ucf:51171
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006122
- Title
- Information Propagation Algorithms for Consensus Formation in Decentralized Multi-Agent Systems.
- Creator
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Hollander, Christopher, Wu, Annie, Shumaker, Randall, Wiegand, Rudolf, Turgut, Damla, Song, Zixia, University of Central Florida
- Abstract / Description
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Consensus occurs within a multi-agent system when every agent is in agreement about the value of some particular state. For example, the color of an LED, the position or magnitude of a vector, a rendezvous location, the most recent state of data within a database, or the identity of a leader are all states that agents might need to agree on in order to execute their tasking.The task of the decentralized consensus problem for multi-agent systems is to design an algorithm that enables agents to...
Show moreConsensus occurs within a multi-agent system when every agent is in agreement about the value of some particular state. For example, the color of an LED, the position or magnitude of a vector, a rendezvous location, the most recent state of data within a database, or the identity of a leader are all states that agents might need to agree on in order to execute their tasking.The task of the decentralized consensus problem for multi-agent systems is to design an algorithm that enables agents to communicate and exchange information such that, in finite time, agents are able to form a consensus without the use of a centralized control mechanism. The primary goal of this research is to introduce and provide supporting evidence for Stochastic Local Observation/Gossip (SLOG) algorithms as a new class of solutions to the decentralized consensus problem for multi-agent systems that lack a centralized controller, with the additional constraints that agents act asynchronously, information is discrete, and all consensus options are equally preferable to all agents. Examples of where these constraints might apply include the spread of social norms and conventions in artificial populations, rendezvous among a set of specific locations, and task assignment.This goal is achieved through a combination of theory and experimentation. Information propagation process and an information propagation algorithm are derived by unifying the general structure of multiple existing solutions to the decentralized consensus problem. They are then used to define two classes of algorithms that spread information across a network and solve the decentralized consensus problem: buffered gossip algorithms and local observation algorithms. Buffered gossip algorithms generalize the behavior of many push-based solutions to the decentralized consensus problem. Local observation algorithms generalize the behavior of many pull-based solutions to the decentralized consensus problem. In the language of object oriented design, buffered gossip algorithms and local observation algorithms are abstract classes; information propagation processes are interfaces. SLOG algorithms combine the transmission mechanisms of buffered gossip algorithms and local observation algorithms into a single "hybrid" algorithm that is able to push and pull information within the local neighborhood. A common mathematical framework is constructed and used to determine the conditions under which each of these algorithms are guaranteed to produce a consensus, and thus solve the decentralized consensus problem. Finally, a series of simulation experiments are conducted to study the performance of SLOG algorithms. These experiments compare the average speed of consensus formation between buffered gossip algorithms, local observation algorithms, and SLOG algorithms over four distinct network topologies.Beyond the introduction of the SLOG algorithm, this research also contributes to the existing literature on the decentralized consensus problem by: specifying a theoretical framework that can be used to explore the consensus behavior of push-based and pull-based information propagation algorithms; using this framework to define buffered gossip algorithms and local observation algorithms as generalizations for existing solutions to the decentralized consensus problem; highlighting the similarities between consensus algorithms within control theory and opinion dynamics within computational sociology, and showing how these research areas can be successfully combined to create new and powerful algorithms; and providing an empirical comparison between multiple information propagation algorithms.
Show less - Date Issued
- 2015
- Identifier
- CFE0005629, ucf:50229
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005629
- Title
- Physical-Virtual Patient Simulators: Bringing Tangible Humanity to Simulated Patients.
- Creator
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Daher, Salam, Welch, Gregory, Gonzalez, Laura, Cendan, Juan, Proctor, Michael, University of Central Florida
- Abstract / Description
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In lieu of real patients, healthcare educators frequently use simulated patients. Simulated patients can be realized in physical form, such as mannequins and trained human actors, or virtual form, such as via computer graphics presented on two-dimensional screens or head-mounted displays. Each of these alone has its strengths and weaknesses. I introduce a new class of physical-virtual patient (PVP) simulators that combine strengths of both forms by combining the flexibility and richness of...
Show moreIn lieu of real patients, healthcare educators frequently use simulated patients. Simulated patients can be realized in physical form, such as mannequins and trained human actors, or virtual form, such as via computer graphics presented on two-dimensional screens or head-mounted displays. Each of these alone has its strengths and weaknesses. I introduce a new class of physical-virtual patient (PVP) simulators that combine strengths of both forms by combining the flexibility and richness of virtual patients with tangible characteristics of a human-shaped physical form that can also exhibit a range of multi-sensory cues, including visual cues (e.g., capillary refill and facial expressions), auditory cues (e.g., verbal responses and heart sounds), and tactile cues (e.g., localized temperature and pulse). This novel combination of integrated capabilities can improve patient simulation outcomes. In my Ph.D. work I focus on three primary areas of related research. First, I describe the realization of the technology for PVPs and results from two user-studies to evaluate the importance of dynamic visuals and human-shaped physical form in terms of perception, behavior, cognition, emotions, and learning.Second, I present a general method to numerically evaluate the compatibility of any simulator-scenario pair in terms of importance and fidelity of cues. This method has the potential to make logistical, economic, and educational impacts on the choices of utilizing existing simulators.Finally, I describe a method for increasing human perception of simulated humans by exposing participants to the simulated human taking part in a short, engaging conversation prior to the simulation.
Show less - Date Issued
- 2018
- Identifier
- CFE0007750, ucf:52402
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007750
- Title
- The Profession of Modeling and Simulations: Unifying the Organization.
- Creator
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Lord, John, Caulkins, Bruce, Truman, Barbara, Maraj, Crystal, Bockelman, Patricia, University of Central Florida
- Abstract / Description
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The organization of Modeling and Simulation (M(&)S) as a profession started in the early twenty-first century spurred by the advent of computers and the vast networking capabilities of contemporary computing. M(&)S is still in its infancy when compared to other disciplines, such as engineering, computer science and mathematics. However, the profession has experienced significant growth in part due to the varied use of M(&)S techniques and tools within almost every discipline.Professional...
Show moreThe organization of Modeling and Simulation (M(&)S) as a profession started in the early twenty-first century spurred by the advent of computers and the vast networking capabilities of contemporary computing. M(&)S is still in its infancy when compared to other disciplines, such as engineering, computer science and mathematics. However, the profession has experienced significant growth in part due to the varied use of M(&)S techniques and tools within almost every discipline.Professional organizations and academic programs supporting M(&)S across the country have started to materialize. In a short timeframe, the growth of these supporting organizations has outpaced their ability to stay unified as a discipline, aligned with standardized Knowledge, Skills, and Abilities (KSAs) and with growing stakeholder needs.Consequently, there appear to be gaps in the M(&)S professional organization. Such as a lack of synchronization between the three primary stakeholder groups of the M(&)S profession: academia, government, and industry. The discipline's professional organization fails to recognize a single body of knowledge as an authoritative reference for M(&)S KSAs. Academic institutions do not have unanimity regarding targeted KSAs. Industry lacks the confidence to hire M(&)S professionals who have a core understanding of KSAs directly associated with the version of M(&)S used by each separate industry.This research study attempts to take a coordinated step forward in unifying the M(&)S discipline by assessing and prioritizing the current competencies and standards required of M(&)S professionals and identifying the needs and competencies valued by primary stakeholders. A survey instrument was developed in conjunction with Rebecca Leis' doctorate research. The instrument was distributed to M(&)S stakeholders to ascertain the breadth of the needed, valued, and required KSAs within the domain. The survey was evaluated by cross-referencing questions and tabulating responses. Results from this research suggest ways in which stakeholders can coordinate efforts in advancing the M(&)S professional organization and support a uniformed set of KSAs needed in academia, government, and industry now and in the future.
Show less - Date Issued
- 2019
- Identifier
- CFE0007489, ucf:52876
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007489
- Title
- The Design and Evaluation of a Video Game to Help Train Perspective-Taking and Empathy in Children with Autism Spectrum Disorder.
- Creator
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Hughes, Darin, Vasquez, Eleazar, Kincaid, John, Marino, Matthew, Lindgren, Robb, University of Central Florida
- Abstract / Description
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This paper discusses the design, implementation, and evaluation of a serious game intended to reinforce applied behavior analysis (ABA) techniques used with children with autism spectrum disorder (ASD) by providing a low cost and easily accessible supplement to traditional methods. Past and recent research strongly supports the use of computer assisted instruction in the education of individuals with ASD (Moore (&) Calvert, 2000; Noor, Shahbodin, (&) Pee, 2012). Computer games have been shown...
Show moreThis paper discusses the design, implementation, and evaluation of a serious game intended to reinforce applied behavior analysis (ABA) techniques used with children with autism spectrum disorder (ASD) by providing a low cost and easily accessible supplement to traditional methods. Past and recent research strongly supports the use of computer assisted instruction in the education of individuals with ASD (Moore (&) Calvert, 2000; Noor, Shahbodin, (&) Pee, 2012). Computer games have been shown to boost confidence and provide calming mechanisms (Griffiths, 2003) while being a safe environment for social exploration and learning (Moore, Cheng, McGrath, (&) Powell, 2005). Games increase children's motivation and thus increase the rate of learning in computer mediated environments (Moore (&) Calvert, 2000). Furthermore, children with ASD are able to understand basic emotions and facial expressions in avatars more easily than in real-world interactions (Moore, Cheng, McGrath, (&) Powell, 2005).Perspective-taking (also known as role-taking) has been shown to be a crucial component and antecedent to empathy (Gomez-Becerra, Martin, Chavez-Brown, (&) Greer, 2007; Peng, Lee, (&) Heeter, 2010). Though symptoms vary across children with ASD, perspective-taking and empathy are abilities that have been shown to be limited across a wide spectrum of individuals with ASD and Asperger's disorder (Gomez-Becerra, Martin, Chavez-Brown, (&) Greer, 2007). A game called WUBeeS was developed to aid young children with ASD in perspective taking and empathy by placing the player in the role of a caregiver to a virtual avatar. It is hypothesized that through the playing of this game over a series of trials, children with ASD will show an increase in the ability to discriminate emotions, provide appropriate responses to basic needs (e.g. feeding the avatar when it is hungry), and be able to communicate more clearly about emotions.
Show less - Date Issued
- 2014
- Identifier
- CFE0005184, ucf:50654
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005184
- Title
- EVOLVING MODELS FROM OBSERVED HUMAN PERFORMANCE.
- Creator
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Fernlund, Hans Karl Gustav, Gonzalez, Avelino J., University of Central Florida
- Abstract / Description
-
To create a realistic environment, many simulations require simulated agents with human behavior patterns. Manually creating such agents with realistic behavior is often a tedious and time-consuming task. This dissertation describes a new approach that automatically builds human behavior models for simulated agents by observing human performance. The research described in this dissertation synergistically combines Context-Based Reasoning, a paradigm especially developed to model tactical...
Show moreTo create a realistic environment, many simulations require simulated agents with human behavior patterns. Manually creating such agents with realistic behavior is often a tedious and time-consuming task. This dissertation describes a new approach that automatically builds human behavior models for simulated agents by observing human performance. The research described in this dissertation synergistically combines Context-Based Reasoning, a paradigm especially developed to model tactical human performance within simulated agents, with Genetic Programming, a machine learning algorithm to construct the behavior knowledge in accordance to the paradigm. This synergistic combination of well-documented AI methodologies has resulted in a new algorithm that effectively and automatically builds simulated agents with human behavior. This algorithm was tested extensively with five different simulated agents created by observing the performance of five humans driving an automobile simulator. The agents show not only the ability/capability to automatically learn and generalize the behavior of the human observed, but they also capture some of the personal behavior patterns observed among the five humans. Furthermore, the agents exhibited a performance that was at least as good as agents developed manually by a knowledgeable engineer.
Show less - Date Issued
- 2004
- Identifier
- CFE0000013, ucf:46068
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000013
- Title
- AN APPROACH TO AUTOMATING DATA COLLECTION FOR SIMULATION.
- Creator
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Portnaya, Irin, Mollaghasemi, Mansooreh, University of Central Florida
- Abstract / Description
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In past years many industries have utilized simulation as a means for decision making. That wave has introduced simulation as a powerful optimization and development tool in the manufacturing industry. Input data collection is a significant and complex event in the process of simulation. The simulation professionals have grown to accept it is as a strenuous but necessary task. Due to the nature of this task, data collection problems are numerous and vary depending on the situation. These...
Show moreIn past years many industries have utilized simulation as a means for decision making. That wave has introduced simulation as a powerful optimization and development tool in the manufacturing industry. Input data collection is a significant and complex event in the process of simulation. The simulation professionals have grown to accept it is as a strenuous but necessary task. Due to the nature of this task, data collection problems are numerous and vary depending on the situation. These problems may involve time consumption, lack of data, lack of structure, etc. This study concentrates on the challenges of input data collection for Discrete Event Simulation in the manufacturing industry and focuses particularly on speed, efficiency, data completeness and data accuracy. It has been observed that many companies have recently utilized commercial databases to store production data. This study proposes that the key to faster and more efficient input data collection is to extract data directly from these sources in a flexible and efficient way. An approach is introduced here to creating a custom software tool for a manufacturing setting that allows input data to be collected and formatted quickly and accurately.The methodology for the development of such a custom tool and its implementation, Part Data Collection, are laid out in this research. The Part Data Collection application was developed to assist in the simulation endeavors of Lockheed Martin Missiles and Fire Control in Orlando, Florida. It was implemented and tested as an aid in a large simulation project, which included modeling a new factory. This implementation resulted in 93% reduction in labor time associated with data collection and significantly improved data accuracy.
Show less - Date Issued
- 2004
- Identifier
- CFE0000025, ucf:46096
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000025
- Title
- EFFECT OF OPERATOR CONTROL CONFIGURATION ON UNMANNED AERIAL SYSTEM TRAINABILITY.
- Creator
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Neumann, John, Kincaid, Peter, University of Central Florida
- Abstract / Description
-
Unmanned aerial systems (UAS) carry no pilot on board, yet they still require live operators to handle critical functions such as mission planning and execution. Humans also interpret the sensor information provided by these platforms. This applies to all classes of unmanned aerial vehicles (UAV's), including the smaller portable systems used for gathering real-time reconnaissance during military operations in urban terrain. The need to quickly and reliably train soldiers to control small...
Show moreUnmanned aerial systems (UAS) carry no pilot on board, yet they still require live operators to handle critical functions such as mission planning and execution. Humans also interpret the sensor information provided by these platforms. This applies to all classes of unmanned aerial vehicles (UAV's), including the smaller portable systems used for gathering real-time reconnaissance during military operations in urban terrain. The need to quickly and reliably train soldiers to control small UAS operations demands that the human-system interface be intuitive and easy to master. In this study, participants completed a series of tests of spatial ability and were then trained (in simulation) to teleoperate a micro-unmanned aerial vehicle equipped with forward and downward fixed cameras. Three aspects of the human-system interface were manipulated to assess the effects on manual control mastery and target detection. One factor was the input device. Participants used either a mouse or a specially programmed game controller (similar to that used with the Sony Playstation 2 video game console). A second factor was the nature of the flight control displays as either continuous or discrete (analog v. digital). The third factor involved the presentation of sensor imagery. The display could either provide streaming video from one camera at a time, or present the imagery from both cameras simultaneously in separate windows. The primary dependent variables included: 1) time to complete assigned missions, 2) number of collisions, 3) number of targets detected, and 4) operator workload. In general, operator performance was better with the game controller than with the mouse, but significant improvement in time to complete occurred over repeated trials regardless of the device used. Time to complete missions was significantly faster with the game controller, and operators also detected more targets without any significant differences in workload compared to mouse users. Workload on repeated trials decreased with practice, and spatial ability was a significant covariate of workload. Lower spatial ability associated with higher workload scores. In addition, demographic data including computer usage and video gaming experience were collected and analyzed, and correlated with performance. Higher video gaming experience was also associated with lower workload.
Show less - Date Issued
- 2006
- Identifier
- CFE0001496, ucf:47080
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001496
- Title
- PREDICTION AND ALLOCATION OF LIVE TO VIRTUAL COMMUNICATION BRIDGING RESOURCES.
- Creator
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lackey, stephanie, Malone, Linda, University of Central Florida
- Abstract / Description
-
This document summarizes a research effort focused on improving live-to-virtual (L-V) communication systems. The purpose of this work is to address a significant challenge facing the tactical communications training community through the development of the Live-to-Virtual Relay Radio Prediction Algorithm and implementation of the algorithm into an Integrated Live-to-Virtual Communications Server prototype device. The motivation for the work and the challenges of integrating live and virtual...
Show moreThis document summarizes a research effort focused on improving live-to-virtual (L-V) communication systems. The purpose of this work is to address a significant challenge facing the tactical communications training community through the development of the Live-to-Virtual Relay Radio Prediction Algorithm and implementation of the algorithm into an Integrated Live-to-Virtual Communications Server prototype device. The motivation for the work and the challenges of integrating live and virtual communications are presented. Details surrounding the formulation of the prediction algorithm and a description of the prototype system, hardware, and software architectures are shared. Experimental results from discrete event simulation analysis and prototype functionality testing accompany recommendations for future investigation. If the methods and technologies summarized are implemented, an estimated equipment savings of 25%-53% and an estimated cost savings of $150,000.00 - $630,000.00 per site are anticipated. Thus, a solution to a critical tactical communications training problem is presented through the research discussed.
Show less - Date Issued
- 2006
- Identifier
- CFE0001401, ucf:47072
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001401
- Title
- QUANTITATIVE HIGH-ANGLE ANNULAR DARK FIELD SCANNING TRANSMISSION ELECTRON MICROSCOPY FOR MATERIALS SCIENCE.
- Creator
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Petrova, Rumyana, Coffey, Kevin, University of Central Florida
- Abstract / Description
-
Scanning transmission electron microscopy (STEM) has been widely used for characterization of materials; to identify micro- and nano-structures within a sample and to analyze crystal and defect structures. High-angle annular dark field (HAADF) STEM imaging using atomic number (Z) contrast has proven capable of resolving atomic structures with better than 2 Å lateral resolution. In this work, the HAADF STEM imaging mode is used in combination with multislice simulations. This combination...
Show moreScanning transmission electron microscopy (STEM) has been widely used for characterization of materials; to identify micro- and nano-structures within a sample and to analyze crystal and defect structures. High-angle annular dark field (HAADF) STEM imaging using atomic number (Z) contrast has proven capable of resolving atomic structures with better than 2 Å lateral resolution. In this work, the HAADF STEM imaging mode is used in combination with multislice simulations. This combination is applied to the investigation of the temperature dependence of the intensity collected by the HAADF detector in silicon, and to convergent beam electron diffraction (CBED) to measure the degree of chemical order in intermetallic nanoparticles. The experimental and simulation results on the highangle scattering of 300 keV electrons in crystalline silicon provide a new contribution to the understanding of the temperature dependence of the HAADF intensity. In the case of 300 keV, the average high-angle scattered intensity slightly decreases as the temperature increases from 100 K to 300 K, and this is different from the temperature dependence at 100 keV and 200 keV where HAADF intensity increases with temperature, as had been previously reported by other workers. The L10 class of hard magnetic materials has attracted continuous attention as a candidate for high-density magnetic recording media, as this phase is known to have large magnetocrystalline anisotropy, with magnetocrystalline anisotropy constant, Ku, strongly dependent on the long-range chemical order parameter, S. A new method is developed to assess the degree of chemical order in small FePt L10 nanoparticles by implementing a CBED diffraction technique. Unexpectedly, the degree of order of individual particles is highly variable and not a simple function of particle size or sample composition. The particle-to-particle variability observed is an important new aspect to the understanding of phase transformations in nanoparticle systems.
Show less - Date Issued
- 2006
- Identifier
- CFE0001267, ucf:46931
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001267
- Title
- IMPROVING PROJECT MANAGEMENT WITH SIMULATION AND COMPLETION DISTRIBUTION FUNCTIONS.
- Creator
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Cates, Grant, Mollaghasemi, Mansooreh, University of Central Florida
- Abstract / Description
-
Despite the critical importance of project completion timeliness, management practices in place today remain inadequate for addressing the persistent problem of project completion tardiness. Uncertainty has been identified as a contributing factor in late projects. This uncertainty resides in activity duration estimates, unplanned upsetting events, and the potential unavailability of critical resources. This research developed a comprehensive simulation based methodology for conducting...
Show moreDespite the critical importance of project completion timeliness, management practices in place today remain inadequate for addressing the persistent problem of project completion tardiness. Uncertainty has been identified as a contributing factor in late projects. This uncertainty resides in activity duration estimates, unplanned upsetting events, and the potential unavailability of critical resources. This research developed a comprehensive simulation based methodology for conducting quantitative project completion-time risk assessments. The methodology enables project stakeholders to visualize uncertainty or risk, i.e. the likelihood of their project completing late and the magnitude of the lateness, by providing them with a completion time distribution function of their projects. Discrete event simulation is used to determine a project's completion distribution function. The project simulation is populated with both deterministic and stochastic elements. Deterministic inputs include planned activities and resource requirements. Stochastic inputs include activity duration growth distributions, probabilities for unplanned upsetting events, and other dynamic constraints upon project activities. Stochastic inputs are based upon past data from similar projects. The time for an entity to complete the simulation network, subject to both the deterministic and stochastic factors, represents the time to complete the project. Multiple replications of the simulation are run to create the completion distribution function. The methodology was demonstrated to be effective for the on-going project to assemble the International Space Station. Approximately $500 million per month is being spent on this project, which is scheduled to complete by 2010. Project stakeholders participated in determining and managing completion distribution functions. The first result was improved project completion risk awareness. Secondly, mitigation options were analyzed to improve project completion performance and reduce total project cost.
Show less - Date Issued
- 2004
- Identifier
- CFE0000209, ucf:46243
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000209
- Title
- RIGHT TURN SPLIT: A NEW DESIGN TO ALLEVIATE WEAVING ON ARTERIAL STREETS.
- Creator
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Shaaban, Khaled, Radwan, Essam, University of Central Florida
- Abstract / Description
-
While weaving maneuvers occur on every type of roadway, most studies have focused on freeway maneuvers. Weaving occurring on non-freeway facilities, such as arterial streets, can cause significant operational problems. Arterial streets weaving typically occur when vehicles coming from a side street at an upstream intersection attempt to enter the main street from one side to reach access points on the opposite site at a downstream intersection by crossing one or more lanes. This dissertation...
Show moreWhile weaving maneuvers occur on every type of roadway, most studies have focused on freeway maneuvers. Weaving occurring on non-freeway facilities, such as arterial streets, can cause significant operational problems. Arterial streets weaving typically occur when vehicles coming from a side street at an upstream intersection attempt to enter the main street from one side to reach access points on the opposite site at a downstream intersection by crossing one or more lanes. This dissertation investigates the type of problems occurring on arterial streets due to the weaving movements and recommends a new design to alleviate weaving on arterial streets. Firstly, the dissertation examined the different weaving movements occurring between two close-spaced intersections at two sites in Florida and explained the breakdown conditions caused by the weaving movements at the two sites. Secondly, the dissertation proposed a new design, Right Turn Split (RTS), to alleviate the delay caused by the weaving movements. The new design proposed separating the worst weaving movement entering the arterial from the other movements and providing a separate path for this movement. The new method is easy to implement and does not require much right of way. Thirdly, the dissertation compared two microscopic models, SimTraffic and VISSIM, to choose the most suitable model to be used to study the operational benefits of the RTS design. Based on the results of the comparison, it was decided to use SimTraffic for the analysis. Fourthly, the dissertation proposed a new calibration and validation procedure for microscopic simulation models. The procedure was applied on SimTraffic using the traffic data from the two studied sites. The proposed procedure appeared to be properly calibrating and validating the SimTraffic simulation model. Finally, the calibrated and validated model was used to study the operational benefits of the RTS design. Using a wide range of geometric and volume conditions, 729 before and after pairs were created to compare the delay of similar scenarios before and after applying the RTS design. The results were analyzed graphically and statistically. The findings of the analysis showed that the RTS design provided lower delay on the arterial street than the original conditions.
Show less - Date Issued
- 2005
- Identifier
- CFE0000402, ucf:46346
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000402
- Title
- SAFETY ISSUES OF RED-LIGHT RUNNING AND UNPROTECTED LEFT-TURN AT SIGNALIZED INTERSECTIONS.
- Creator
-
Yan, Xuedong, Radwan, Essam, University of Central Florida
- Abstract / Description
-
Crashes categorized as running red light or left turning are most likely to occur at signalized intersections and resulted in substantial severe injuries and property damages. This dissertation mainly focused on these two types of vehicle crashes and the research methodology involved several perspectives. To examine the overall characteristics of red-light running and left-turning crashes, firstly, this study applied 1999-2001 Florida traffic crash data to investigate the accident propensity...
Show moreCrashes categorized as running red light or left turning are most likely to occur at signalized intersections and resulted in substantial severe injuries and property damages. This dissertation mainly focused on these two types of vehicle crashes and the research methodology involved several perspectives. To examine the overall characteristics of red-light running and left-turning crashes, firstly, this study applied 1999-2001 Florida traffic crash data to investigate the accident propensity of three aspects of risk factors related to traffic environments, driver characteristics, and vehicle types. A quasi-induced exposure concept and statistical techniques including classification tree model and multiple logistic regression were used to perform this analysis. Secondly, the UCF driving simulator was applied to test the effect of a proposed new pavement marking countermeasure which purpose is to reduce the red-light running rate at signalized intersections. The simulation experiment results showed that the total red-light running rate with marking is significantly lower than that without marking. Moreover, deceleration rate of stopping drivers with marking for the higher speed limit are significantly less than those without marking. These findings are encouraging and suggesting that the pavement marking may result in safety enhancement as far as right-angle and rear-end traffic crashes at signalized intersections. Thirdly, geometric models to compute sight distances of unprotected left-turns were developed for different signalized intersection configurations including a straight approach leading to a straight one, a straight approach leading to a curved one, and a curved approach leading to a curved one. The models and related analyses can be used to layout intersection design or evaluate the sight distance problem of an existing intersection configuration to ensure safe left-turn maneuvers by drivers.
Show less - Date Issued
- 2005
- Identifier
- CFE0000451, ucf:46389
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000451
- Title
- EFFECTS OF THREE INSTRUCTIONAL SCHEDULES ON SKILL ACQUISITION AND GENERALIZATION IN THE USE OF TWO-WAY RADIOS TO REPORT TASK COMPLETION BY HIGH SCHOOL STUDENTS WITH MODERATE INTELLECTUAL DISABILITIES.
- Creator
-
Perez-Turner, Geraldine, Miller, Kevin, University of Central Florida
- Abstract / Description
-
Educators of students with moderate and severe intellectual disabilities face a significant challenge in preparing their students while in school to function, acquire, and maintain skills that would facilitate successful performance in the workforce while in supported and/or independent employment after graduation. The field of special education still debates about the best way to teach students with moderate intellectual disabilities, the best setting for their instruction and the best...
Show moreEducators of students with moderate and severe intellectual disabilities face a significant challenge in preparing their students while in school to function, acquire, and maintain skills that would facilitate successful performance in the workforce while in supported and/or independent employment after graduation. The field of special education still debates about the best way to teach students with moderate intellectual disabilities, the best setting for their instruction and the best instructional schedule. The current research investigated the effectiveness and efficiency of three instructional schedules in the skill acquisition and generalization of two-way radio usage to report task completion by high school students with moderate intellectual disabilities. The instructional schedules investigated were: (a) community-based instruction only (CBI), (b) community based instruction plus simulated instruction in the classroom-same day (CBISC) and (c) simulated instruction in the classroom only (SICO). A Multiple Probe Design across participants with intermittent probe trials within each instructional group, and an added generalization phase (Horner & Baer, 1978; Tawney & Gast, 1984; Alberto & Troutman, 2003) was employed in this study. Nine high school students with moderate intellectual disabilities, three in each instructional schedule, were taught to use a two-way radio to report task completion. The results of the study revealed that the CBI instructional schedule was the overall most efficient instructional schedule for skill acquisition. Two of the CBI participants required the least number of trials to learn to use a two-way radio to report task completion. The second most efficient schedule was the CBISC and the least efficient instructional schedule was the SICO. Based on Mean scores, learning efficiency appeared to be greater for the participants in the CBI and CBISC instructional schedule. These participants required the least number of intrusive prompts. Results indicated that the SICO instructional scheduled was more efficient for only one participant. This participant only required verbal prompts for acquisition of the skill. However, participant one on the SICO instructional schedule required the most intrusive prompts of all participants across groups. For generalization, the CBISC instructional schedule appeared to be the most effective. In this schedule, the two participants that concluded the study generalized the skill across three novel settings with 100% accuracy. The SICO schedule, also had two participants generalized the skill across three novel settings; however, one participant in that group failed to generalize the skill in two settings. The CBI instructional schedule appeared to be the least effective for skill generalization in this study. In this schedule, only one participant generalized the skill in all three novel settings.
Show less - Date Issued
- 2005
- Identifier
- CFE0000398, ucf:46322
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000398