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Title: Free trade: An address delivered before the Democratic Association of Brussels, Belgium, January 9, 1848.
Creator: Marx, Karl, Engels, Friedrich, Kelley, Florence
Date Issued: 1921
Identifier: 358384, CFDT358384, ucf:5209
Format: Document (PDF)
PURL: http://purl.flvc.org/FCLA/DT/358384

Title: The nature of freedom.
Creator: Carmichael, Peter Archibald
Date Issued: c1931
Identifier: 369219, CFDT369219, ucf:5388
Format: Document (PDF)
PURL: http://purl.flvc.org/FCLA/DT/369219

Title: The Design, Implementation, and Refinement of Wait-Free Algorithms and Containers.
Creator: Feldman, Steven, Dechev, Damian, Heinrich, Mark, Orooji, Ali, Mucciolo, Eduardo, University of Central Florida
Abstract / Description: My research has been on the development of concurrent algorithms for shared memory systems that provide guarantees of progress.Research into such algorithms is important to developers implementing applications on mission critical and time sensitive systems.These guarantees of progress provide safety properties and freedom from many hazards, such as dead-lock, live-lock, and thread starvation.In addition to the safety concerns, the fine-grained synchronization used in implementing these...
Show moreMy research has been on the development of concurrent algorithms for shared memory systems that provide guarantees of progress.Research into such algorithms is important to developers implementing applications on mission critical and time sensitive systems.These guarantees of progress provide safety properties and freedom from many hazards, such as dead-lock, live-lock, and thread starvation.In addition to the safety concerns, the fine-grained synchronization used in implementing these algorithms promises to provide scalable performance in massively parallel systems.My research has resulted in the development of wait-free versions of the stack, hash map, ring buffer, vector, and a multi-word compare-and-swap algorithms.Through this experience, I have learned and developed new techniques and methodologies for implementing non-blocking and wait-free algorithms.I have worked with and refined existing techniques to improve their practicality and applicability.In the creation of the aforementioned algorithms, I have developed an association model for use with descriptor-based operations.This model, originally developed for the multi-word compare-and-swap algorithm, has been applied to the design of the vector and ring buffer algorithms.To unify these algorithms and techniques, I have released Tervel, a wait-free library of common algorithms and containers.This library includes a framework that simplifies and improves the design of non-blocking algorithms.I have reimplemented several algorithms using this framework and the resulting implementation exhibits less code duplication and fewer perceivable states.When reimplementing algorithms, I have adapted their Application Programming Interface (API) specification to remove ambiguity and non-deterministic behavior found when using a sequential API in a concurrent environment.To improve the performance of my algorithm implementations, I extended OVIS's Lightweight Distributed Metric Service (LDMS)'s data collection and transport system to support performance monitoring using perf_event and PAPI libraries.These libraries have provided me with deeper insights into the behavior of my algorithms, and I was able to use these insights to improve the design and performance of my algorithms.
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Date Issued: 2015
Identifier: CFE0005946, ucf:50813
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005946

Title: AN EVALUATION OF THE EFFECTS OF A LEISURE EDUCATION CURRICULUM ON DELINQUENTS' MOTIVATION, KNOWLEDGE, AND BEHAVIOR CHANGES RELATED TO BOREDOM.
Creator: Finn, Jr., Paul, Wan, Thomas, University of Central Florida
Abstract / Description: Adolescents today have more unsupervised and unstructured free time than ever before. Poor decisions by youth during periods of free time may lead to substance abuse, teen pregnancy and juvenile delinquency. The highest frequency of juvenile crime, a major social problem, occurs during the 2-4 hours following the end of the school day. Research has demonstrated the benefits of engaging adolecents in prosocial leisure activity. However, no research has studied the issues of free time and...
Show moreAdolescents today have more unsupervised and unstructured free time than ever before. Poor decisions by youth during periods of free time may lead to substance abuse, teen pregnancy and juvenile delinquency. The highest frequency of juvenile crime, a major social problem, occurs during the 2-4 hours following the end of the school day. Research has demonstrated the benefits of engaging adolecents in prosocial leisure activity. However, no research has studied the issues of free time and leisure education with a delinquent population. This paper documents the impact of a leisure education curriculum on a population of delinquent youth in a randomized experiment. The delinquent youths who received the leisure education reported higher intrinsic motivation and better use of free time. The delinquent youths also reported improved decision making related to their involvement in healthy, prosocial free time activities. Finally, the improvement in the delinquent youths' motivation influenced a significant decrease in the delinquent youths' proneness to boredom during their free time.
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Date Issued: 2006
Identifier: CFE0001472, ucf:47104
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001472

Title: Lithographic Vertical-Cavity Surface-Emitting Lasers.
Creator: Zhao, Guowei, Deppe, Dennis, Likamwa, Patrick, Fathpour, Sasan, Sundaram, Kalpathy, University of Central Florida
Abstract / Description: Remarkable improvements in vertical-cavity surface-emitting lasers (VCSELs) have been made by the introduction of mode- and current-confining oxide optical aperture now used commercially. However, the oxide aperture blocks heat flow inside the device, causing a larger thermal resistance, and the internal strain caused by the oxide can degrade device reliability, also the diffusion process used for the oxide formation can limit device uniformity and scalability.Oxide-free lithographic VCSELs...
Show moreRemarkable improvements in vertical-cavity surface-emitting lasers (VCSELs) have been made by the introduction of mode- and current-confining oxide optical aperture now used commercially. However, the oxide aperture blocks heat flow inside the device, causing a larger thermal resistance, and the internal strain caused by the oxide can degrade device reliability, also the diffusion process used for the oxide formation can limit device uniformity and scalability.Oxide-free lithographic VCSELs are introduced to overcome these device limitations, with both the mode and current confined within the lithographically defined intracavity mesa, scaling and mass production of small size device could be possible. The 3 ?m diameter lithographic VCSEL shows a threshold current of 260 ?A, differential quantum efficiency of 60% and maximum output power density of 65 kW/cm2, and shows single-mode single-polarization operation with side-mode-suppression-ratio over 25 dB at output power up to 1 mW. The device also shows reliable operation during 1000 hours stress test with high injection current density of 142 kA/cm2. The lithographic VCSELs have much lower thermal resistance than oxide-confined VCSELs due to elimination of the oxide aperture. The improved thermal property allows the device to have wide operating temperature range of up to 190 (&)deg;C heat sink temperature, high output power density especially in small device, high rollover current density and high rollover cavity temperature. Research is still underway to reduce the operating voltage of lithographic VCSELs for high wall plug efficiency, and the voltage of 6 (&)#181;m device at injection current density of 10 kA/cm2 is reduces to 1.83 V with optimized mesa and DBR mirror structure. The lithographic VCSELS are promising to become the next generation VCSEL technology.
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Date Issued: 2012
Identifier: CFE0004634, ucf:49912
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004634

Title: FORMALITY.
Creator: Emley, Bryce, Thaxton, Terry, University of Central Florida
Abstract / Description: Of the many aspects of the composition of poetry, the most common component of the form involves emotional response. There is an infinite number of ways to write a poem, and likewise an infinite number of forms which a poem can be structured according to. In writing this collection of poems composing my thesis, I set out to write poetry in as many ways as I could to explore how different forms, devices, voices, points of view, sounds, tones, and as many other variables as I could think of...
Show moreOf the many aspects of the composition of poetry, the most common component of the form involves emotional response. There is an infinite number of ways to write a poem, and likewise an infinite number of forms which a poem can be structured according to. In writing this collection of poems composing my thesis, I set out to write poetry in as many ways as I could to explore how different forms, devices, voices, points of view, sounds, tones, and as many other variables as I could think of affect poetry as stimulus. The poems in this collection cover a range of classic poetic forms and styles as well as variations of free verse and contemporary forms. My hope is that the readers of these poems will be able to experience a wide range of emotional responses and gain the same insight into the vast abilities inherent in poetry that I gained in writing them.
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Date Issued: 2011
Identifier: CFH0003783, ucf:44735
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH0003783

Title: Joint Optimization of Illumination and Communication for a Multi-Element VLC Architecture.
Creator: Ibne Mushfique, Sifat, Yuksel, Murat, Pourmohammadi Fallah, Yaser, Turgut, Damla, University of Central Florida
Abstract / Description: Because of the ever increasing demand wireless data in the modern era, the Radio Frequency (RF) spectrum is becoming more congested. The remaining RF spectrum is being shrunk at a very heavy rate, and spectral management is becoming more difficult. Mobile data is estimated to grow more than 10 times between 2013 and 2019, and due to this explosion in data usage, mobile operators are having serious concerns focusing on public Wireless Fidelity (Wi-Fi) and other alternative technologies....
Show moreBecause of the ever increasing demand wireless data in the modern era, the Radio Frequency (RF) spectrum is becoming more congested. The remaining RF spectrum is being shrunk at a very heavy rate, and spectral management is becoming more difficult. Mobile data is estimated to grow more than 10 times between 2013 and 2019, and due to this explosion in data usage, mobile operators are having serious concerns focusing on public Wireless Fidelity (Wi-Fi) and other alternative technologies. Visible Light Communication (VLC) is a recent promising technology complementary to RF spectrum which operates at the visible light spectrum band (roughly 400 THz to 780 THz) and it has 10,000 times bigger size than radio waves (roughly 3 kHz to 300 GHz). Due to this tremendous potential, VLC has captured a lot of interest recently as there is already an extensive deployment of energy efficient Light Emitting Diodes (LEDs). The advancements in LED technology with fast nanosecond switching times is also very encouraging. In this work, we present hybrid RF/VLC architecture which is capable of providing simultaneous lighting and communication coverage in an indoor setting. The architecture consists of a multi-element hemispherical bulb design, where it is possible to transmit multiple data streams from the multi-element hemispherical bulb using LED modules. We present the detailed components of the architecture and make simulations considering various VLC transmitter configurations. Also, we devise an approach for an efficient bulb design mechanism to maintain both illumination and communication at a satisfactory rate, and analyze it in the case of two users in a room. The approach involves formulating an optimization problem and tackling the problem using a simple partitioning algorithm. The results indicate that good link quality and high spatial reuse can be maintained in a typical indoor communication setting.
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Date Issued: 2018
Identifier: CFE0007016, ucf:52025
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007016

Title: REACTION VELOCITIES IN FREE STANDING ALUMINUM AND COPPER OXIDE THIN FILMS.
Creator: Erickson, Matthew, Coffey, Kevin, University of Central Florida
Abstract / Description: In this work we investigate the reaction propagation velocity of aluminum and copper oxide Metastable Intermolecular Composites (MIC's). All samples were deposited in a magnetron sputtering system using 2 aluminum targets and 2 copper targets. The copper is sputtered in an oxygen rich environment in order to obtain copper oxide rich films. Three different layer structures are used for various measurements that are composed of alternating 20 layer pairs, 30 layer pairs, and 40 layer pairs....
Show moreIn this work we investigate the reaction propagation velocity of aluminum and copper oxide Metastable Intermolecular Composites (MIC's). All samples were deposited in a magnetron sputtering system using 2 aluminum targets and 2 copper targets. The copper is sputtered in an oxygen rich environment in order to obtain copper oxide rich films. Three different layer structures are used for various measurements that are composed of alternating 20 layer pairs, 30 layer pairs, and 40 layer pairs. All layer pairs maintain a constant total thickness of 3.2 microns. Each layer structure can be prepared independent of a substrate and is measured with the use of photodiodes or with direct device contact. Aluminum and copper oxide structures have potential use as propellants and additives to explosives, thus, accurate propagation velocity or burn rate measurements are important. The developed measurement system for burn rate measurements of Al/CuO MIC's can achieve and accuracy of 0.1 m/s. In order to determine the velocity limiting characteristics, MIC's on glass and silicon substrates were measured as well as free standing Al/CuO MIC's. Separate burn rate measurement devices were created in order to handle the variety of substrates. In addition, the ignition energy of the Al/CuO MIC was studied to further characterize the samples. This was done using both voltage and current probes of a reacting sample. Rutherford backscattering spectroscopy (RBS) was used for sample composition calibration. The pre- and post-reaction Al/CuO MIC's were also characterized by transmission electron microscopy (TEM).
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Date Issued: 2009
Identifier: CFE0002786, ucf:48093
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002786

Title: Practical Dynamic Transactional Data Structures.
Creator: Laborde, Pierre, Dechev, Damian, Leavens, Gary, Turgut, Damla, Mucciolo, Eduardo, University of Central Florida
Abstract / Description: Multicore programming presents the challenge of synchronizing multiple threads.Traditionally, mutual exclusion locks are used to limit access to a shared resource to a single thread at a time.Whether this lock is applied to an entire data structure, or only a single element, the pitfalls of lock-based programming persist.Deadlock, livelock, starvation, and priority inversion are some of the hazards of lock-based programming that can be avoided by using non-blocking techniques.Non-blocking...
Show moreMulticore programming presents the challenge of synchronizing multiple threads.Traditionally, mutual exclusion locks are used to limit access to a shared resource to a single thread at a time.Whether this lock is applied to an entire data structure, or only a single element, the pitfalls of lock-based programming persist.Deadlock, livelock, starvation, and priority inversion are some of the hazards of lock-based programming that can be avoided by using non-blocking techniques.Non-blocking data structures allow scalable and thread-safe access to shared data by guaranteeing, at least, system-wide progress.In this work, we present the first wait-free hash map which allows a large number of threads to concurrently insert, get, and remove information.Wait-freedom means that all threads make progress in a finite amount of time --- an attribute that can be critical in real-time environments.We only use atomic operations that are provided by the hardware; therefore, our hash map can be utilized by a variety of data-intensive applications including those within the domains of embedded systems and supercomputers.The challenges of providing this guarantee make the design and implementation of wait-free objects difficult.As such, there are few wait-free data structures described in the literature; in particular, there are no wait-free hash maps.It often becomes necessary to sacrifice performance in order to achieve wait-freedom.However, our experimental evaluation shows that our hash map design is, on average, 7 times faster than a traditional blocking design.Our solution outperforms the best available alternative non-blocking designs in a large majority of cases, typically by a factor of 15 or higher.The main drawback of non-blocking data structures is that only one linearizable operation can be executed by each thread, at any one time.To overcome this limitation we present a framework for developing dynamic transactional data containers.Transactional containers are those that execute a sequence of operations atomically and in such a way that concurrent transactions appear to take effect in some sequential order.We take an existing algorithm that transforms non-blocking sets into static transactional versions (LFTT), and we modify it to support maps.We implement a non-blocking transactional hash map using this new approach.We continue to build on LFTT by implementing a lock-free vector using a methodology to allow LFTT to be compatible with non-linked data structures.A static transaction requires all operands and operations to be specified at compile-time, and no code may be executed between transactions.These limitations render static transactions impractical for most use cases.We modify LFTT to support dynamic transactions, and we enhance it with additional features.Dynamic transactions allow operands to be specified at runtime rather than compile-time, and threads can execute code between the data structure operations of a transaction.We build a framework for transforming non-blocking containers into dynamic transactional data structures, called Dynamic Transactional Transformation (DTT), and provide a library of novel transactional containers.Our library provides the wait-free progress guarantee and supports transactions among multiple data structures, whereas previous work on data structure transactions has been limited to operating on a single container.Our approach is 3 times faster than software transactional memory, and its performance matches its lock-free transactional counterpart.
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Date Issued: 2018
Identifier: CFE0007215, ucf:52212
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007215

Title: MICROMACHINED ELECTROCHEMICAL SENSORS FOR HYDROGEN PEROXIDE AND CHLORINE DETECTION.
Creator: Mehta, Anjum, Cho, Hyoung (Joe), University of Central Florida
Abstract / Description: Hydrogen peroxide and chlorine detection is critical for many biological and environmental applications. Hydrogen peroxide plays important roles in a variety of fields including plant physiology, medical, environmental and biochemical applications. Its role in plant defense and signal transduction, diseases such as Parkinson's and Alzhemier's, industrial processes such as disinfection and wastewater treatment and biochemical enzymatic reactions is critical. Given the gamut of areas that...
Show moreHydrogen peroxide and chlorine detection is critical for many biological and environmental applications. Hydrogen peroxide plays important roles in a variety of fields including plant physiology, medical, environmental and biochemical applications. Its role in plant defense and signal transduction, diseases such as Parkinson's and Alzhemier's, industrial processes such as disinfection and wastewater treatment and biochemical enzymatic reactions is critical. Given the gamut of areas that hydrogen peroxide is a key component of; its detection assumes great importance. Similarly chlorine has long been used as a disinfectant for making drinking water safe, but excessive chlorination is an environmental and health hazard in itself. In this work, micromachining techniques have been used to design, fabricate and test electrochemical sensors and microneedle structure that can be integrated for detection of hydrogen peroxide and free chlorine. A novel nanomaterial has been integrated with the hydrogen peroxide microsensor, which greatly increases the sensor lifetime and robustness. Miniaturization, low detection limits, high sensitivity and selectivity, as well as ease of fabrication are some of the other advantages of this work.
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Date Issued: 2005
Identifier: CFE0000895, ucf:46627
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000895

Title: FREE TO BE ACCOUNTABLE: EXTENDED SELF AS A MODERATOR OF CHEATING AMONG THOSE PRIMED WITH DETERMINISM.
Creator: Iula, Vincent M., Whitten, Shannon N., University of Central Florida
Abstract / Description: The idea that free will may be an illusion has been a source of great concern. It has led to suggestions that it may be wise to avoid public discussion of this topic lest it lead to a general moral decay. This concern has seemingly been supported by research demonstrating that individuals, when primed with the notion they lack free will, tend to cheat more and prefer less retributive punishment. The current research suggests that these effects can be moderated by the introduction of a second...
Show moreThe idea that free will may be an illusion has been a source of great concern. It has led to suggestions that it may be wise to avoid public discussion of this topic lest it lead to a general moral decay. This concern has seemingly been supported by research demonstrating that individuals, when primed with the notion they lack free will, tend to cheat more and prefer less retributive punishment. The current research suggests that these effects can be moderated by the introduction of a second prime. In experiment one, participants believed they were being tested on note-taking and the subsequent recall of the content of two articles when, in fact, the dependent measure was actually the degree to which, after being primed with the articles, they cheated on a math task. It was hypothesized that the cheating effect noted in prior research would be moderated by the introduction of a second prime � one that extends the concept of self beyond our dualistic intuitions. In a second experiment, it was hypothesized that this prime would also moderate the reported reduction of preference toward retributivist punishment. In each experiment, the results trended in the direction hypothesized but in neither case were they statistically significant. The difficulties surrounding methodology and reproducibility in this type of research is discussed and suggestions for improvements in experiment design are offered.
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Date Issued: 2016
Identifier: CFH2000018, ucf:45594
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000018

Title: AN INVESTIGATION OF STUDENTSÃƒÂƒÃ‚Â‚ÃƒÂ‚Ã‚Â' PROBLEM SOLVING SKILLS IN AN INTRODUCTORY PHYSICS CLASS.
Creator: McDonald, Frank, Jeanpierre, Bobby, University of Central Florida
Abstract / Description: The purpose of this study was to document the specific errors that introductory physics students make in each phase of the solution of Force and Motion problems. A mixed methods design was used to identify those errors, and it was determined that the errors which students made the most frequently were the omission of mgcosθ , mgsinθ, and the lack of a clearly defined coordinate system as part of the free-body diagram. Additionally, there was a negative statistically significant...
Show moreThe purpose of this study was to document the specific errors that introductory physics students make in each phase of the solution of Force and Motion problems. A mixed methods design was used to identify those errors, and it was determined that the errors which students made the most frequently were the omission of mgcosθ , mgsinθ, and the lack of a clearly defined coordinate system as part of the free-body diagram. Additionally, there was a negative statistically significant relationship between the quality of the free-body diagram and the quality of equations that were produced to describe the objectÃƒÂƒÃ‚Â‚ÃƒÂ‚Ã‚Â's motion. The results indicate that students do not have a full understanding of the role of a free-body diagram or its relationship to the system of equations that are generated as a result of the application of NewtonÃƒÂƒÃ‚Â‚ÃƒÂ‚Ã‚Â's Second Law to the free-body diagram.
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Date Issued: 2010
Identifier: CFE0003456, ucf:48407
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003456

Title: Fabrication and Investigation of an enzyme-free, Nanoparticle-based Biosensor for Hydrogen Peroxide determination.
Creator: Neal, Craig, Seal, Sudipta, Cho, Hyoung Jin, Florczyk, Stephen, University of Central Florida
Abstract / Description: Electrochemical biosensors often employ enzymes as detection elements. These sensors are highly selective towards target analytes, however the scope of their application is limited by the poor stability of the enzyme. In this study, multi-valent inorganic cerium oxide nanoparticles were used as detection elements for the analysis of hydrogen peroxide. The electrochemical response of the cerium oxide towards hydrogen peroxide analyte is defined through cyclic voltammetry and chronoamperometry....
Show moreElectrochemical biosensors often employ enzymes as detection elements. These sensors are highly selective towards target analytes, however the scope of their application is limited by the poor stability of the enzyme. In this study, multi-valent inorganic cerium oxide nanoparticles were used as detection elements for the analysis of hydrogen peroxide. The electrochemical response of the cerium oxide towards hydrogen peroxide analyte is defined through cyclic voltammetry and chronoamperometry. This response was found to be dependent on nanoparticle Ce3+:Ce4+ redox state ratio and this property is exploited to fabricate a biosensor. As produced, the biosensor demonstrated sensitivity at picomolar analyte concentrations. Further, the sensitivity of the electrode is stable across a range of temperatures and pH's which inhibit the function of standard enzyme-based sensors. Additionally, the produced sensor retained function in sheep serum demonstrating the high selectivity and robustness of the sensor.
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Date Issued: 2016
Identifier: CFE0006362, ucf:51540
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006362

Title: High-Performance Composable Transactional Data Structures.
Creator: Zhang, Deli, Dechev, Damian, Leavens, Gary, Zou, Changchun, Lin, Mingjie, University of Central Florida
Abstract / Description: Exploiting the parallelism in multiprocessor systems is a major challenge in the post ``power wall'' era. Programming for multicore demands a change in the way we design and use fundamental data structures. Concurrent data structures allow scalable and thread-safe accesses to shared data. They provide operations that appear to take effect atomically when invoked individually.A main obstacle to the practical use of concurrent data structures is their inability to support composable operations,...
Show moreExploiting the parallelism in multiprocessor systems is a major challenge in the post ``power wall'' era. Programming for multicore demands a change in the way we design and use fundamental data structures. Concurrent data structures allow scalable and thread-safe accesses to shared data. They provide operations that appear to take effect atomically when invoked individually.A main obstacle to the practical use of concurrent data structures is their inability to support composable operations, i.e., to execute multiple operations atomically in a transactional manner. The problem stems from the inability of concurrent data structure to ensure atomicity of transactions composed from operations on a single or multiple data structures instances. This greatly hinders software reuse because users can only invoke data structure operations in a limited number of ways.Existing solutions, such as software transactional memory (STM) and transactional boosting, manage transaction synchronization in an external layer separated from the data structure's own thread-level concurrency control. Although this reduces programming effort, it leads to significant overhead associated with additional synchronization and the need to rollback aborted transactions. In this dissertation, I address the practicality and efficiency concerns by designing, implementing, and evaluating high-performance transactional data structures that facilitate the development of future highly concurrent software systems.Firstly, I present two methodologies for implementing high-performance transactional data structures based on existing concurrent data structures using either lock-based or lock-free synchronizations. For lock-based data structures, the idea is to treat data accessed by multiple operations as resources. The challenge is for each thread to acquire exclusive access to desired resources while preventing deadlock or starvation. Existing locking strategies, like two-phase locking and resource hierarchy, suffer from performance degradation under heavy contention, while lacking a desirable fairness guarantee. To overcome these issues, I introduce a scalable lock algorithm for shared-memory multiprocessors addressing the resource allocation problem. It is the first multi-resource lock algorithm that guarantees the strongest first-in, first-out (FIFO) fairness. For lock-free data structures, I present a methodology for transforming them into high-performance lock-free transactional data structures without revamping the data structures' original synchronization design. My approach leverages the semantic knowledge of the data structure to eliminate the overhead of false conflicts and rollbacks.Secondly, I apply the proposed methodologies and present a suite of novel transactional search data structures in the form of an open source library. This is interesting not only because the fundamental importance of search data structures in computer science and their wide use in real world programs, but also because it demonstrate the implementation issues that arise when using the methodologies I have developed. This library is not only a compilation of a large number of fundamental data structures for multiprocessor applications, but also a framework for enabling composable transactions, and moreover, an infrastructure for continuous integration of new data structures. By taking such a top-down approach, I am able to identify and consider the interplay of data structure interface operations as a whole, which allows for scrutinizing their commutativity rules and hence opens up possibilities for design optimizations.Lastly, I evaluate the throughput of the proposed data structures using transactions with randomly generated operations on two difference hardware systems. To ensure the strongest possible competition, I chose the best performing alternatives from state-of-the-art locking protocols and transactional memory systems in the literature. The results show that it is straightforward to build efficient transactional data structures when using my multi-resource lock as a drop-in replacement for transactional boosted data structures. Furthermore, this work shows that it is possible to build efficient lock-free transactional data structures with all perceived benefits of lock-freedom and with performance far better than generic transactional memory systems.
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Date Issued: 2016
Identifier: CFE0006428, ucf:51453
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006428

Title: Optimization problem in single period markets.
Creator: Jiang, Tian, Yong, Jiongmin, Qi, Yuanwei, Shuai, Zhisheng, University of Central Florida
Abstract / Description: There had been a number of researches that investigated on the security market without transactioncosts. The focus of this research is in the area that when the security market with transaction costsis fair and in such fair market how one chooses a suitable portfolio to optimize the financial goal.The research approach adopted in this thesis includes linear algebra and elementary probability.The thesis provides evidence that we can maximize expected utility function to achieve our goal...
Show moreThere had been a number of researches that investigated on the security market without transactioncosts. The focus of this research is in the area that when the security market with transaction costsis fair and in such fair market how one chooses a suitable portfolio to optimize the financial goal.The research approach adopted in this thesis includes linear algebra and elementary probability.The thesis provides evidence that we can maximize expected utility function to achieve our goal(maximize expected return under certain risk tolerance). The main conclusions drawn from thisstudy are under certain conditions the security market is arbitrage-free, and we can always find anoptimal portfolio maximizing certain expected utility function.
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Date Issued: 2013
Identifier: CFE0004696, ucf:49875
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004696

Title: FUNDAMENTAL ASPECTS OF REGENERATIVE CERIUM OXIDE NANOPARTICLES AND THEIR APPLICATIONS IN NANOBIOTECHNOLOGY.
Creator: Patil, Swanand, Seal, Sudipta, University of Central Florida
Abstract / Description: Cerium oxide has been used extensively for various applications over the past two decades. The use of cerium oxide nanoparticles is beneficial in present applications and can open avenues for future applications. The present study utilizes the microemulsion technique to synthesize uniformly distributed cerium oxide nanoparticles. The same technique was also used to synthesize cerium oxide nanoparticles doped with trivalent elements (La and Nd). The fundamental study of cerium oxide...
Show moreCerium oxide has been used extensively for various applications over the past two decades. The use of cerium oxide nanoparticles is beneficial in present applications and can open avenues for future applications. The present study utilizes the microemulsion technique to synthesize uniformly distributed cerium oxide nanoparticles. The same technique was also used to synthesize cerium oxide nanoparticles doped with trivalent elements (La and Nd). The fundamental study of cerium oxide nanoparticles identified variations in properties as a function of particle size and also due to doping with trivalent elements (La and Nd). It was found that the lattice parameter of cerium oxide nanoparticles increases with decrease in particle size. Also Raman allowed mode shift to lower energies and the peak at 464 cm-1 becomes broader and asymmetric. The size dependent changes in cerium oxide were correlated to increase in oxygen vacancy concentration in the cerium oxide lattice. The doping of cerium oxide nanoparticles with trivalent elements introduces more oxygen vacancies and expands the cerium oxide lattice further (in addition to the lattice expansion due to the size effect). The lattice expansion is greater for La-doped cerium oxide nanoparticles compared to Nd-doping due to the larger ionic radius of La compared to Nd, the lattice expansion is directly proportional to the dopant concentration. The synthesized cerium oxide nanoparticles were used to develop an electrochemical biosensor of hydrogen peroxide (H2O2). The sensor was useful to detect H2O2 concentrations as low as 1µM in water. Also the preliminary testing of the sensor on tomato stem and leaf extracts indicated that the sensor can be used in practical applications such as plant physiological studies etc. The nanomolar concentrations of cerium oxide nanoparticles were also found to be useful in decreasing ROS (reactive oxygen species) mediated cellular damages in various in vitro cell cultures. Cerium oxide nanoparticles reduced the cellular damages to the normal breast epithelial cell line (CRL 8798) induced by X-rays and to the Keratinocyte cell line induced by UV irradiation. Cerium oxide nanoparticles were also found to be neuroprotective to adult rat spinal cord and retinal neurons. We propose that cerium oxide nanoparticles act as free radical scavenger (via redox reactions on its surface) to decrease the ROS induced cellular damages. Additionally, UV-visible spectroscopic studies indicated that cerium oxide nanoparticles possess auto-regenerative property by switching its oxidation state between Ce3+ and Ce4+. The auto-regenerative antioxidant property of these nanoparticles appears to be a key component in all the biological applications discussed in the present study.
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Date Issued: 2006
Identifier: CFE0001271, ucf:46932
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001271

Title: THE GENERATION AND SCAVENGING OF RADICALS VIA CERIUM AND NANOCERIA.
Creator: Heckert, Eric, self, william, University of Central Florida
Abstract / Description: Cerium is the most abundant of the rare earth metals, found on average at a level of 66 parts per million in the earth's crust. The unique redox properties of cerium and cerium oxide nanoparticles have led to its use in a wide variety of industrial and commercial uses such as oxygen sensors, fertilizers and as a catalyst to remove toxic gases in automobile exhaust. The use of cerium has also garnered interest in the nanotechnology field. Nanoceria has been generated in its oxide form as...
Show moreCerium is the most abundant of the rare earth metals, found on average at a level of 66 parts per million in the earth's crust. The unique redox properties of cerium and cerium oxide nanoparticles have led to its use in a wide variety of industrial and commercial uses such as oxygen sensors, fertilizers and as a catalyst to remove toxic gases in automobile exhaust. The use of cerium has also garnered interest in the nanotechnology field. Nanoceria has been generated in its oxide form as nanoparticles and nanorods. Recently, nanoceria has been shown to protect against oxidative stress in both animal and cell culture models. Although not fully understood, this observed protective effect of nanoceria is believed to be the result of recently identified SOD mimetic activity. Currently there is little understanding as to how nanoceria is capable of scavenging radicals or what properties makes nanoceria an effective SOD mimetic. Our data shows strong evidence that the oxidation state of nanoceria is directly related to its reported SOD mimetic activity. As such, future studies of nanoceria should be mindful of the oxidation state of nanoceria preparations as only nanoceria with a high concentration of cerium (III) have shown effective SOD mimetic activity. In addition to the characterization of nanoceria and its SOD mimetic activity, we have evidence that free cerium is capable of generating radicals and damaging DNA in vitro in the presence of hydrogen peroxide. These data strongly suggests that the rare earth inner-transition metal cerium is capable of generating hydroxyl radicals via a Fenton-like reaction. Based on these results the use of free cerium salts should be monitored to limit environmental exposure to cerium. Altogether our data would suggest that cerium by virtue of its unique redox chemistry is quite capable of accepting and donating electrons from its surroundings. In its free form cerium is able to redox cycle easily and can generate radicals. However, paradoxically nanoceria may not easily redox cycle due to the bound lattice structure of the particle. The unique nature of nanoceria and cerium leads to a unique circumstance where nanoceria is a radical scavenger while free cerium generates radicals. As such, further investigation is needed to insure that leeching or cerium from nanoceria does not abrogate any potential benefit nanoceria may provide.
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Date Issued: 2007
Identifier: CFE0001892, ucf:47417
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001892

Title: MESHFREE APPROXIMATION METHODS FOR FREE-FORM OPTICAL SURFACES WITH APPLICATIONS TO HEAD-WORN DISPLAYS.
Creator: Cakmakci, Ozan, Rolland, Jannick, University of Central Florida
Abstract / Description: Compact and lightweight optical designs achieving acceptable image quality, field of view, eye clearance, eyebox size, operating across the visible spectrum, are the key to the success of next generation head-worn displays. The first part of this thesis reports on the design, fabrication, and analysis of off-axis magnifier designs. The first design is catadioptric and consists of two elements. The lens utilizes a diffractive optical element and the mirror has a free-form surface described...
Show moreCompact and lightweight optical designs achieving acceptable image quality, field of view, eye clearance, eyebox size, operating across the visible spectrum, are the key to the success of next generation head-worn displays. The first part of this thesis reports on the design, fabrication, and analysis of off-axis magnifier designs. The first design is catadioptric and consists of two elements. The lens utilizes a diffractive optical element and the mirror has a free-form surface described with an x-y polynomial. A comparison of color correction between doublets and single layer diffractive optical elements in an eyepiece as a function of eye clearance is provided to justify the use of a diffractive optical element. The dual-element design has an 8 mm diameter eyebox, 15 mm eye clearance, 20 degree diagonal full field, and is designed to operate across the visible spectrum between 450-650 nm. 20% MTF at the Nyquist frequency with less than 3% distortion has been achieved in the dual-element head-worn display. An ideal solution for a head-worn display would be a single free-form surface mirror design. A single surface mirror does not have dispersion; therefore, color correction is not required. A single surface mirror can be made see-through by machining the appropriate surface shape on the opposite side to form a zero power shell. The second design consists of a single off-axis free-form mirror described with an x-y polynomial, which achieves a 3 mm diameter exit pupil, 15 mm eye relief, and a 24 degree diagonal full field of view. The second design achieves 10% MTF at the Nyquist frequency set by the pixel spacing of the VGA microdisplay with less than 3% distortion. Both designs have been fabricated using diamond turning techniques. Finally, this thesis addresses the question of "what is the optimal surface shape for a single mirror constrained in an off-axis magnifier configuration with multiple fields?" Typical optical surfaces implemented in raytrace codes today are functions mapping two dimensional vectors to real numbers. The majority of optical designs to-date have relied on conic sections and polynomials as the functions of choice. The choice of conic sections is justified since conic sections are stigmatic surfaces under certain imaging geometries. The choice of polynomials from the point of view of surface description can be challenged. A polynomial surface description may link a designer's understanding of the wavefront aberrations and the surface description. The limitations of using multivariate polynomials are described by a theorem due to Mairhuber and Curtis from approximation theory. This thesis proposes and applies radial basis functions to represent free-form optical surfaces as an alternative to multivariate polynomials. We compare the polynomial descriptions to radial basis functions using the MTF criteria. The benefits of using radial basis functions for surface description are summarized in the context of specific head-worn displays. The benefits include, for example, the performance increase measured by the MTF, or the ability to increase the field of view or pupil size. Even though Zernike polynomials are a complete and orthogonal set of basis over the unit circle and they can be orthogonalized for rectangular or hexagonal pupils using Gram-Schmidt, taking practical considerations into account, such as optimization time and the maximum number of variables available in current raytrace codes, for the specific case of the single off-axis magnifier with a 3 mm pupil, 15 mm eye relief, 24 degree diagonal full field of view, we found the Gaussian radial basis functions to yield a 20% gain in the average MTF at 17 field points compared to a Zernike (using 66 terms) and an x-y polynomial up to and including 10th order. The linear combination of radial basis function representation is not limited to circular apertures. Visualization tools such as field map plots provided by nodal aberration theory have been applied during the analysis of the off-axis systems discussed in this thesis. Full-field displays are used to establish node locations within the field of view for the dual-element head-worn display. The judicious separation of the nodes along the x-direction in the field of view results in well-behaved MTF plots. This is in contrast to an expectation of achieving better performance through restoring symmetry via collapsing the nodes to yield field-quadratic astigmatism.
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Date Issued: 2008
Identifier: CFE0002479, ucf:47674
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002479

Title: AN INVESTIGATION OF THE EVOLUTION OF THE MINIMALIST SHOETHROUGH A REVIEW OF RESEARCH LITERATURE.
Creator: Sommarvong, Samantha, Fisher, Thomas, University of Central Florida
Abstract / Description: As an investigation of the evolution of the minimalist shoes, the purpose of this thesis was to examine popularity trends of the rise and fall of the minimalist movement. By evaluating the history and research behind the designs of the minimalist shoes, this thesis viewed the peak in popularity when minimalist shoes first made their debut. Initially, footwear sales skyrocketed upon its introduction. Its popularity grew due the prospective effects of improving athletic performance and the...
Show moreAs an investigation of the evolution of the minimalist shoes, the purpose of this thesis was to examine popularity trends of the rise and fall of the minimalist movement. By evaluating the history and research behind the designs of the minimalist shoes, this thesis viewed the peak in popularity when minimalist shoes first made their debut. Initially, footwear sales skyrocketed upon its introduction. Its popularity grew due the prospective effects of improving athletic performance and the possibility of decreasing the prevalence of running-related injuries. To understand the sales trends of the footwear industry, various shoe examples from the different categories of footwear padding were also examined. Hence, after learning more about each type of footwear, it is crucial to understand how to transition safely and without injury. Injury prevalence has been suggested to be associated with the change in biomechanics involved with changing a runner's footwear. Through the review of research literature on the subject, 33 sources of peer-reviewed studies, found via Google Scholar or EBSCOHost using select key word searches, were taken into account. After reviewing the results and conclusions, a common finding suggest that more research is needed to come to clear consensus. There is not enough evidence to suggest that the use of minimalist shoes either lowered the risk of injury or improved performance. Hence, the decline of minimalist movement may have been due to the unfulfilled benefits that were proposed. After consumers did not reap the benefits of transitioning to minimalist shoes, sales trends continued to fall.
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Date Issued: 2015
Identifier: CFH0004905, ucf:45495
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH0004905

Title: UCF STUDENT PERCEPTIONS OF A SMOKE-FREE CAMPUS POLICY.
Creator: Roman, Alyssa, Ford, Jason, University of Central Florida
Abstract / Description: Within the last few decades, the prevalence of cigarette smoking has decreased because of the vast amount of research which indicates that smoking leads to health problems many of which are potentially fatal. Also, smoking harms not only those whom choose to smoke but non-smokers in the area are affected by even low levels of cigarette smoke. Thus, cigarette smoking has become a public health concern. Around the globe, countries are passing smoke-free laws in public areas such as businesses,...
Show moreWithin the last few decades, the prevalence of cigarette smoking has decreased because of the vast amount of research which indicates that smoking leads to health problems many of which are potentially fatal. Also, smoking harms not only those whom choose to smoke but non-smokers in the area are affected by even low levels of cigarette smoke. Thus, cigarette smoking has become a public health concern. Around the globe, countries are passing smoke-free laws in public areas such as businesses, restaurants, and bars. In the United States, many universities have enacted smoke-free campus policies to ensure the health of all their students in all places on campus. The purpose of this research is to identify the support or opposition for a smoke-free campus policy at the University of Central Florida by UCF students. A survey was distributed to undergraduate students at UCF which asks whether they would support such a policy along with characterizing questions about their smoking habits, lifestyle, history, and opinion. The analysis of the data shows that the majority of UCF student would support a smoke-free campus policy.
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Date Issued: 2011
Identifier: CFH0003706, ucf:44716
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH0003706

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