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- Title
- Innovative video error resilient techniques for MBMS systems.
- Creator
- Sanigepalli, Praveen., Florida Atlantic University, Kalva, Hari, Furht, Borko, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In the current communications age, the capabilities of mobile devices are increasing. The mobiles are capable of communicating at data rates of hundreds of mbps on 4G networks. This enables playback of rich multimedia content comparable to internet and television networks. However, mobile networks need to be spectrum-efficient to be affordable to users. Multimedia Broadcast Multicast Systems (MBMS) is a wireless broadcasting standard that is being drafted to enable multimedia broadcast while...
Show moreIn the current communications age, the capabilities of mobile devices are increasing. The mobiles are capable of communicating at data rates of hundreds of mbps on 4G networks. This enables playback of rich multimedia content comparable to internet and television networks. However, mobile networks need to be spectrum-efficient to be affordable to users. Multimedia Broadcast Multicast Systems (MBMS) is a wireless broadcasting standard that is being drafted to enable multimedia broadcast while focusing on being spectrum-efficient. The hybrid video coding techniques facilitate low bitrate transmission, but result in dependencies across frames. With a mobile environment being error prone, no error correction technique can guarantee error free transmission. Such errors propagate, resulting in quality degradation. With numerous mobiles sharing the broadcast session, any error resilient scheme should account for heterogeneous device capabilities and channel conditions. The current research on wireless video broadcasting focuses on network based techniques such as FEC and retransmissions, which add bandwidth overhead. There is a need to design innovative error resilient techniques that make video codec robust with minimal bandwidth overhead. This Dissertation introduces novel techniques in the area of MBMS systems. First, robust video structures are proposed in Periodic Intra Frame based Prediction (PIFBP) and Periodic Anchor Frame based Prediction (PAFBP) schemes. In these schemes, the Intra frames or anchor frames serve as reference frames for prediction during GOP period. The intermediate frames are independent of others; any errors in such frames are not propagated, thereby resulting in error resilience. In prior art, intra block rate is adapted based on the channel characteristics for error resilience. This scheme has been generalized in multicasting to address a group of users sharing the same session. Average packet loss is used to determine the intra block rate. This improves performance of the overall group and strives for consistent performance. Also, the inherent diversity in the broadcasting session can be used for its advantage. With mobile devices capable of accessing a WLAN during broadcast, they form an adhoc network on a WLAN to recover lost packets. New error recovery schemes are proposed for error recovery and their performance comparison is presented.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/12187
- Subject Headings
- Wireless communication systems, Signal processing, Digital video, Multimedia systems, Digital communications, Data transmission systems
- Format
- Document (PDF)
- Title
- Interactive computer aided digital control design.
- Creator
- Yakali, Huseyin Hakan., Florida Atlantic University, Roth, Zvi S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This thesis outlines the design philosophy and implementation aspects of a new interactive CAD tool implemented in BASIC language on an IBM PC/AT computer for single input single output (SISO) digital control systems. The direct Digital Control design method presented is classical in nature. The program main features are: (1) The use of Modified z-transform to model the effects of transport delay due to control computation time. (2) The use of windows on a split screen to allow the designer...
Show moreThis thesis outlines the design philosophy and implementation aspects of a new interactive CAD tool implemented in BASIC language on an IBM PC/AT computer for single input single output (SISO) digital control systems. The direct Digital Control design method presented is classical in nature. The program main features are: (1) The use of Modified z-transform to model the effects of transport delay due to control computation time. (2) The use of windows on a split screen to allow the designer observation of the closed-loop step response while systematically shaping a root locus or synthesizing closed-loop pole/zero patterns. (3) Display of system response in between sampling instants.
Show less - Date Issued
- 1988
- PURL
- http://purl.flvc.org/fcla/dt/14488
- Subject Headings
- Computer-aided design, Digital control systems, Engineering design--Data processing
- Format
- Document (PDF)
- Title
- Integrating Multi-user Scheduling with Retransmission Diversity over Wireless Links.
- Creator
- Li, Irena, Zhuang, Hanqi, Wang, Xin, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Research presented in this thesis develops a mainly theoretical basis and computer models for enhancing the throughput of multi-user wireless communication networks. The cross-layer combination of an adaptive modulation and coding (AMC) scheme at the physical layer and the use of automatic repeat request (ARQ) retransmi ssions at the data link layer is integrated into a scheduling framework for multi-user networks. Scheduling algorithms incorporating retransmission diversity are derived for...
Show moreResearch presented in this thesis develops a mainly theoretical basis and computer models for enhancing the throughput of multi-user wireless communication networks. The cross-layer combination of an adaptive modulation and coding (AMC) scheme at the physical layer and the use of automatic repeat request (ARQ) retransmi ssions at the data link layer is integrated into a scheduling framework for multi-user networks. Scheduling algorithms incorporating retransmission diversity are derived for three cases of typical network traffic: best-effort, non-realtime, and realtime. For each case, numeric computer si mulations of wireless communications over Nakagami-m block fading channels are developed to examine the effectiveness of the formulated schemes.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fau/fd/FA00012533
- Subject Headings
- Wireless communication networks, Code division multiple access, Modulation (Electronics), Signal processing (Digital techniques)
- Format
- Document (PDF)
- Title
- Information hiding: Digital watermarking techniques.
- Creator
- Sadicoff, Mauricio Levy., Florida Atlantic University, Larrondo-Petrie, Maria M., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Digital Watermarking is a multimedia technique recently developed with the purpose of enhancing copyright protection on multimedia files. This thesis presents a survey of digital watermark features and classifications. It also proposes a classification method that includes most of previous classifications. The thesis then proceeds to detail two digital watermarking methods, Lower Significant Bit Encoding and Spread Spectrum Encoding. Software is designed and implemented to show the...
Show moreDigital Watermarking is a multimedia technique recently developed with the purpose of enhancing copyright protection on multimedia files. This thesis presents a survey of digital watermark features and classifications. It also proposes a classification method that includes most of previous classifications. The thesis then proceeds to detail two digital watermarking methods, Lower Significant Bit Encoding and Spread Spectrum Encoding. Software is designed and implemented to show the capabilities and behavior of each method. The software also shows how each method reacts to four typical transformations (attacks). The results of applying the two methods and their survival rates against the typical transformations are discussed in detail. Finally, the source code for the software is made available.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12897
- Subject Headings
- Computer software--Development, Digital watermarking, Data encryption (Computer science)
- Format
- Document (PDF)
- Title
- Extensions to real-time object-oriented software design methodologies.
- Creator
- Woodcock, Timothy G., Florida Atlantic University, Fernandez, Eduardo B., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Real-time systems are systems where time is considered a system resource that needs to be managed. Time is usually represented in these systems as a deadline to complete a task. Unfortunately, by adding timing to even simple algorithms, it complicates them greatly. Real-time systems are by nature difficult and complex to understand. Object-oriented methodologies have attributes that allow real-time systems to be designed and implemented with less error and some control over the resultant...
Show moreReal-time systems are systems where time is considered a system resource that needs to be managed. Time is usually represented in these systems as a deadline to complete a task. Unfortunately, by adding timing to even simple algorithms, it complicates them greatly. Real-time systems are by nature difficult and complex to understand. Object-oriented methodologies have attributes that allow real-time systems to be designed and implemented with less error and some control over the resultant complexity. With object-oriented design, the system is modeled in the environment that it will be used in. Objects themselves, are partitions of the system, into logical, understandable units. In this dissertation, we start by surveying the current real-time object-oriented design methodologies. By comparing these methodologies and developing a set of criteria for evaluating them, we discover that certain aspects of these methodologies still need some work. The most important aspects of the methodologies are understanding the effects of deadlines on statechart behavioral models and understanding the effects of deadlines when object models are inherited or undergo aggregation. The effects of deadlines on statecharts are then explored in detail. There are two basic ways that deadlines are added to statecharts. The first, and most popular, is adding timing as a condition on a state transition. The second is adding a count down timer to a state and forcing a transition if the timer reaches zero. We show that these are equivalent and can be used interchangeably to simplify designs. Next, the effects of deadlines on behavior models when the corresponding object models undergo inheritance or aggregation are studied. We will first analyze the effects on the behavior model when object inheritance is encountered. We found eight ways that the behavior model can be modified and still maintain the properties of inheritance. Finally, deadlines are added and the analysis is repeated.
Show less - Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/12493
- Subject Headings
- Real-time data processing, Computer software--Development, Object-oriented programming (Computer science)
- Format
- Document (PDF)
- Title
- Mitigating worm propagation on virtual LANs.
- Creator
- Sun, Xiaoguang., Florida Atlantic University, Rajput, Saeed, Hsu, Sam, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Recent worms have used sophisticated propagation techniques to propagate faster than the patch distribution and have utilized previously unknown vulnerabilities. To mitigate repetition of such epidemics in future, active defense mechanisms are needed that not only identify malicious activity, but can also defend against widespread outbreak. We provide a framework capable of reacting quickly to quarantine infections. The fundamental components of our framework are detector and VLAN switch. We...
Show moreRecent worms have used sophisticated propagation techniques to propagate faster than the patch distribution and have utilized previously unknown vulnerabilities. To mitigate repetition of such epidemics in future, active defense mechanisms are needed that not only identify malicious activity, but can also defend against widespread outbreak. We provide a framework capable of reacting quickly to quarantine infections. The fundamental components of our framework are detector and VLAN switch. We have provided a proof of concept implementation, where we use the Blaster worm as an example, and demonstrate that detection of worms is possible, and individual infected hosts can be isolated quickly. Furthermore, using Monte Carlo simulations, we show that such containment of future epidemics is possible. In addition, we also compute the overhead of detection and mitigation approaches and have shown that our approach has lower overhead compared to the others.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13369
- Subject Headings
- Wireless LANs--Security measures, Wireless communication systems--Security measures, Computer viruses--Prevention, Computer security
- Format
- Document (PDF)
- Title
- Modeling and measurement of the response of small antennas near multilayered two or three-dimensional dielectric bodies.
- Creator
- Ponce de Leon, Lorenzo Angel., Florida Atlantic University, Helmken, Henry, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
A theory of the circular loop antenna constructed from finite conductivity wire is developed via a Fourier series expansion of the currents in the loop. Models for a family of small loop antennas are also presented. A new high sensitivity and selectivity heterodyne fiber optic based electromagnetic field detector is developed compatible with open antenna range measurements made at low signal levels and in the presence of strong interfering signals. A new analytical solution pertaining to the...
Show moreA theory of the circular loop antenna constructed from finite conductivity wire is developed via a Fourier series expansion of the currents in the loop. Models for a family of small loop antennas are also presented. A new high sensitivity and selectivity heterodyne fiber optic based electromagnetic field detector is developed compatible with open antenna range measurements made at low signal levels and in the presence of strong interfering signals. A new analytical solution pertaining to the response of a disk loaded dipole antenna representing a dipole configured on a lossy dielectric medium is developed using a field compensation theorem and a geometrical theory of diffraction. The multipole expansions for the scattered fields of a multilayered infinite cylinder illuminated by oblique incidence plane wave are formulated and programmed for numerical analysis. The response of cylinders with constitutive parameters reflecting those used in human phantoms are calculated. The response of a small antenna proximal to a multilayered cylinder is analyzed. The scattered fields from multilayered bodies are coupled to a small wire antenna using a combined methods induced electromagnetic force (EMF) technique. New results concerning the response of a loop antenna near a multilayered body obtained via a zero and first phase current model are presented. The new technique is applied in the analysis of human phantoms tested in an open field antenna range. Validation of the theory of multilayered human phantoms with measurements using the new detector is demonstrated.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/12294
- Subject Headings
- Antennas (Electronics)
- Format
- Document (PDF)
- Title
- Estimation of information-theoretics-based delay-bounds in ATM networks.
- Creator
- Wei, Liqun., Florida Atlantic University, Hsu, Sam, Neelakanta, Perambur S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This thesis addresses a method of deducing the statistical upper and lower bounds associated with the cell-transfer delay variations (CDVs) encountered by the cells transmitted in the asynchronous transfer mode (ATM) networks due to cell losses. This study focuses on: (1) Estimating CDV arising from multiplexing/switching for both constant bit rate and variable bit rate services via simulations. (2) Deducing an information-theoretics based new technique to get an insight of the combined BER...
Show moreThis thesis addresses a method of deducing the statistical upper and lower bounds associated with the cell-transfer delay variations (CDVs) encountered by the cells transmitted in the asynchronous transfer mode (ATM) networks due to cell losses. This study focuses on: (1) Estimating CDV arising from multiplexing/switching for both constant bit rate and variable bit rate services via simulations. (2) Deducing an information-theoretics based new technique to get an insight of the combined BER-induced and multiplexing/switching-induced CDVs in ATM networks. Algorithms on the CDV statistics are derived and the lower and upper bounds of the statistics are obtained via simulations in respect of CBR and VBR traffics. These bounds bounds are useful in the cell-admission control (CAC) strategies adapted in ATM transmissions. Inferential remarks indicating the effects of traffic parameters (such as bandwidth, burstiness etc.) on the values of the statistical bounds are presented, and scope for further work is indicated.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/15444
- Subject Headings
- Asynchronous transfer mode, Telecommunication, Computer networks, Broadband communication systems
- Format
- Document (PDF)
- Title
- Course scheduling support system.
- Creator
- Khan, Jawad Ahmed., Florida Atlantic University, Levow, Roy B., Hsu, Sam, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The Course Scheduling Support System is designed to facilitate manual generation of the faculty course scheduling process. It aids in assigning faculty to courses and assigning each course section to their time block. It captures historic and current scheduling information in an organized manner making information needed to create new schedules more readily and quickly available. The interaction between user and database is made as friendly as possible so that managing, manipulating,...
Show moreThe Course Scheduling Support System is designed to facilitate manual generation of the faculty course scheduling process. It aids in assigning faculty to courses and assigning each course section to their time block. It captures historic and current scheduling information in an organized manner making information needed to create new schedules more readily and quickly available. The interaction between user and database is made as friendly as possible so that managing, manipulating, populating and retrieving scheduling data is simple and efficient. We have implemented an open source web-based prototype of the proposed system using PHP, MySQL, and the Apache Web Server. It can be invoked with a standard Web browser and has an intuitive user interface. It provides tools for customizing web forms that can be easily used by non-technical users. Our department plans to deploy this system by Fall 2006.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13343
- Subject Headings
- Scheduling--Data processing, Constraints (Artificial intelligence), Electronic data processing--Distributed processing
- Format
- Document (PDF)
- Title
- DCVS logic synthesis.
- Creator
- Xiao, Kang., Florida Atlantic University, Barrett, Raymond L. Jr., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Implementation of CMOS combinational logic with Differential Cascode Voltage Switch logic (DCVS) may have many advantages over the traditional CMOS logic approaches with respect to device count, layout density and timing. DCVS is an ideal target technology for a logic synthesis system in that it provides a complete function cover by providing the function and its complement simultaneously. DCVS is also more testable due to this. We have developed for IBM's DCVS technology a synthesis...
Show moreImplementation of CMOS combinational logic with Differential Cascode Voltage Switch logic (DCVS) may have many advantages over the traditional CMOS logic approaches with respect to device count, layout density and timing. DCVS is an ideal target technology for a logic synthesis system in that it provides a complete function cover by providing the function and its complement simultaneously. DCVS is also more testable due to this. We have developed for IBM's DCVS technology a synthesis algorithm and a new test generation approach, that are based on topologies rather than individual logic functions. We have found that 19 and 363 DCVS topologies can represent 256 and 65,536 functions, respectively, for the 3- and 4-varaible cases. Physical defect analysis was conducted with the aid of a building block approach to analyze the n-type logic tree and provides a basis for evolving hierarchical test pattern generation for the topologies.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14850
- Subject Headings
- Integrated circuits--Very large scale integration--Data processing, Metal oxide semiconductors, Complementary, Computer-aided design, Electronic systems, Logic design--Data processing
- Format
- Document (PDF)
- Title
- Correcting noisy data and expert analysis of the correction process.
- Creator
- Seiffert, Christopher N., Florida Atlantic University, Khoshgoftaar, Taghi M., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This thesis expands upon an existing noise cleansing technique, polishing, enabling it to be used in the Software Quality Prediction domain, as well as any other domain where the data contains continuous values, as opposed to categorical data for which the technique was originally designed. The procedure is applied to a real world dataset with real (as opposed to injected) noise as determined by an expert in the domain. This, in combination with expert assessment of the changes made to the...
Show moreThis thesis expands upon an existing noise cleansing technique, polishing, enabling it to be used in the Software Quality Prediction domain, as well as any other domain where the data contains continuous values, as opposed to categorical data for which the technique was originally designed. The procedure is applied to a real world dataset with real (as opposed to injected) noise as determined by an expert in the domain. This, in combination with expert assessment of the changes made to the data, provides not only a more realistic dataset than one in which the noise (or even the entire dataset) is artificial, but also a better understanding of whether the procedure is successful in cleansing the data. Lastly, this thesis provides a more in-depth view of the process than previously available, in that it gives results for different parameters and classifier building techniques. This allows the reader to gain a better understanding of the significance of both model generation and parameter selection.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13223
- Subject Headings
- Computer interfaces--Software--Quality control, Acoustical engineering, Noise control--Computer programs, Expert systems (Computer science), Software documentation
- Format
- Document (PDF)
- Title
- THE DESIGN OF HIGH FREQUENCY OSCILLATORS: NOISE CHARACTERIZATION, DESIGN THEORY, AND MEASUREMENTS.
- Creator
- VICTOR, ALAN MICHAEL., Florida Atlantic University, Gazourian, Martin G., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
A design theory for high frequency oscillators is presented. Emphasis is placed on oscillator design techniques which are applicable to the electrical tuning of LC and transmission line resonators. Attention is paid to design approaches which yield an oscillator with high spectral purity and a large signal to noise ratio. Theory and measurements demonstrate for the oscillator configurations investigated the a small L/C ratio is desirable for improved oscillator signal to noise ratio....
Show moreA design theory for high frequency oscillators is presented. Emphasis is placed on oscillator design techniques which are applicable to the electrical tuning of LC and transmission line resonators. Attention is paid to design approaches which yield an oscillator with high spectral purity and a large signal to noise ratio. Theory and measurements demonstrate for the oscillator configurations investigated the a small L/C ratio is desirable for improved oscillator signal to noise ratio. Equations are developed which define the noise figure the oscillator due to the additive noise of the active device. This analysis demonstrates the need for a high device starting transconductance which should be subsequently reduced during oscillation to minimize the device noise contribution. A relationship is developed between the receiver dynamic range and the oscillator signal to the noise ratio. Oscillator designs in the region 20 Mhz - 200 Mhz verify the analysis. A unified approach to large signal oscillator design is investigated and relationships to oscillator signal to noise ratio using the previously developed theory are noted
Show less - Date Issued
- 1980
- PURL
- http://purl.flvc.org/fcla/dt/14043
- Subject Headings
- Oscillators, Audio-frequency
- Format
- Document (PDF)
- Title
- THE DESIGN OF SWITCHED-CAPACITOR HIGHPASS FILTERS.
- Creator
- LEE, KING FU., Florida Atlantic University, Gazourian, Martin G., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The design of high order switched-capacitor highpass filters is presented. Emphasis is placed on the design procedures of cascaded biquadratic sections and ladder network realizations of switchedcapacitor highpass filters. The stability problem of the doubly terminated switched-capacitor ladder highpass filter is discussed. Design examples are presented to illustrate the design procedures. The sensitivities of the realization methods are discussed. An .analytical equation of the gain...
Show moreThe design of high order switched-capacitor highpass filters is presented. Emphasis is placed on the design procedures of cascaded biquadratic sections and ladder network realizations of switchedcapacitor highpass filters. The stability problem of the doubly terminated switched-capacitor ladder highpass filter is discussed. Design examples are presented to illustrate the design procedures. The sensitivities of the realization methods are discussed. An .analytical equation of the gain deviation for the cascaded biquadratic sections realization is derived. Monte Carlo analysis is performed for the design examples. The results of the analyses are compared to reveal the differences in sensitivities in terms of the order of the filters and the type of realizations.
Show less - Date Issued
- 1983
- PURL
- http://purl.flvc.org/fcla/dt/14169
- Subject Headings
- Switched capacitor circuits, Digital filters (Mathematics)
- Format
- Document (PDF)
- Title
- A very high-performance neural network system architecture using grouped weight quantization.
- Creator
- Karaali, Orhan., Florida Atlantic University, Shankar, Ravi, Gluch, David P., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Recently, Artificial Neural Network (ANN) computing systems have become one of the most active and challenging areas of information processing. The successes of experimental neural computing systems in the fields of pattern recognition, process control, robotics, signal processing, expert system, and functional analysis are most promising. However due to a number of serious problems, only small size fully connected neural networks have been implemented to run in real-time. The primary problem...
Show moreRecently, Artificial Neural Network (ANN) computing systems have become one of the most active and challenging areas of information processing. The successes of experimental neural computing systems in the fields of pattern recognition, process control, robotics, signal processing, expert system, and functional analysis are most promising. However due to a number of serious problems, only small size fully connected neural networks have been implemented to run in real-time. The primary problem is that the execution time of neural networks increases exponentially as the neural network's size increases. This is because of the exponential increase in the number of multiplications and interconnections which makes it extremely difficult to implement medium or large scale ANNs in hardware. The Modular Grouped Weight Quantization (MGWQ) presented in this dissertation is an ANN design which assures that the number of multiplications and interconnections increase linearly as the neural network's size increases. The secondary problems are related to scale-up capability, modularity, memory requirements, flexibility, performance, fault tolerance, technological feasibility, and cost. The MGWQ architecture also resolves these problems. In this dissertation, neural network characteristics and existing implementations using different technologies are described. Their shortcomings and problems are addressed, and solutions to these problems using the MGWQ approach are illustrated. The theoretical and experimental justifications for MGWQ are presented. Performance calculations for the MGWQ architecture are given. The mappings of the most popular neural network models to the proposed architecture are demonstrated. System level architecture considerations are discussed. The proposed ANN computing system is a flexible and a realistic way to implement large fully connected networks. It offers very high performance using currently available technology. The performance of ANNs is measured in terms of interconnections per second (IC/S); the performance of the proposed system changes between 10^11 to 10^14 IC/S. In comparison, SAIC's DELTA II ANN system achieves 10^7. A Cray X-MP achieves 5*10^7 IC/S.
Show less - Date Issued
- 1989
- PURL
- http://purl.flvc.org/fcla/dt/12245
- Subject Headings
- Neural circuitry, Neural computers, Computer architecture
- Format
- Document (PDF)
- Title
- A visual perception threshold matching algorithm for real-time video compression.
- Creator
- Noll, John M., Florida Atlantic University, Pandya, Abhijit S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
A barrier to the use of digital imaging is the vast storage requirements involved. One solution is compression. Since imagery is ultimately subject to human visual perception, it is worthwhile to design and implement an algorithm which performs compression as a function of perception. The underlying premise of the thesis is that if the algorithm closely matches visual perception thresholds, then its coded images contain only the components necessary to recreate the perception of the visual...
Show moreA barrier to the use of digital imaging is the vast storage requirements involved. One solution is compression. Since imagery is ultimately subject to human visual perception, it is worthwhile to design and implement an algorithm which performs compression as a function of perception. The underlying premise of the thesis is that if the algorithm closely matches visual perception thresholds, then its coded images contain only the components necessary to recreate the perception of the visual stimulus. Psychophysical test results are used to map the thresholds of visual perception, and develop an algorithm that codes only the image content exceeding those thresholds. The image coding algorithm is simulated in software to demonstrate compression of a single frame image. The simulation results are provided. The algorithm is also adapted to real-time video compression for implementation in hardware.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14857
- Subject Headings
- Image processing--Digital techniques, Computer algorithms, Visual perception, Data compression (Computer science)
- Format
- Document (PDF)
- Title
- A study on the electromagnetic performance of body-worn radio units in the presence of scatterers in the proximity.
- Creator
- Peterson, Vance Howard, Florida Atlantic University, Ungvichian, Vichate, Neelakanta, Perambur S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The research addressed refers to a study on the electromagnetic performance aspects of body-worn radio units operating in the presence of scatterers in close proximity, using analytical, numerical, and experimental methods. The application potentials of such methods include evaluating the integrity of radio units such as cell phones. Consistent with the scope of the study above, considered in this research are specific details on analytical and numerical modeling of the effects of a nearby...
Show moreThe research addressed refers to a study on the electromagnetic performance aspects of body-worn radio units operating in the presence of scatterers in close proximity, using analytical, numerical, and experimental methods. The application potentials of such methods include evaluating the integrity of radio units such as cell phones. Consistent with the scope of the study above, considered in this research are specific details on analytical and numerical modeling of the effects of a nearby conducting cylindrical object on the electromagnetic field near a human-model phantom. Calculations are performed using the Finite Difference Time Domain (FDTD) method. Considered are various separations of the body wearing the test radio unit from the proximal object and polarization of the incident wave. An anechoic chamber and the test setup used for the measurement of EM field amplitudes near a saline-water phantom are described. Within the anechoic chamber, a small shielded loop is used as a field measurement probe and is positioned near the test phantom. The field probe orientation was in the vertical plane for characterizing the prevailing electromagnetic field intensity. This study indicates that variations in the field amplitude near the phantom occur, which are responsive to phantom rotation and measurement distance from the phantom. The electromagnetic field amplitude decreases rapidly with increasing distance between the probe and the surface of the phantom. The analysis is also extended to examine the electromagnetic field distribution in the gap between a human body phantom model and a nearby conducting cylinder. An appropriate three-dimensional FDTD method is presented and applied to a near-field problem of analyzing the influence of proximal conductive objects on fields near a phantom wearing an RF unit.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fau/fd/FADT12085
- Subject Headings
- Scattering (Mathematics), Sound-waves (Scattering), Electromagnetic waves--Scattering, Electromagnetism--Computer simulation, Finite differences, Time-domain analysis
- Format
- Document (PDF)
- Title
- A study on glucose metabolism: Computer simulation and modeling.
- Creator
- Leesirikul, Meta., Florida Atlantic University, Neelakanta, Perambur S., Roth, Zvi S., Morgera, Salvatore D., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Sorensen's model of glucose metabolism and regulation is reconstructed using SimulinkRTM. Most of the existing glucose metabolism models consist of several mass balance equations that interact with each others. Graphical format used by SimulinkRTM provides a visualized perspective of such relations so that it is easier to modify the model on ad hoc basis. Type-I and Type-II diabetes with relevant clinical details are simulated. Further, a control strategy is introduced in order to simulate...
Show moreSorensen's model of glucose metabolism and regulation is reconstructed using SimulinkRTM. Most of the existing glucose metabolism models consist of several mass balance equations that interact with each others. Graphical format used by SimulinkRTM provides a visualized perspective of such relations so that it is easier to modify the model on ad hoc basis. Type-I and Type-II diabetes with relevant clinical details are simulated. Further, a control strategy is introduced in order to simulate the control of exogenous insulin pump. Simulated results are consistent with available clinical data. Living systems in general, exhibit both stochastical and deterministic characteristics. Activities such as glucose metabolism traditionally modeled do not include stochastical properties, nor that they are viewed in the large framework of complex system with explicit interaction details. Currently, a complexity system model is developed to describe the glucose metabolism related activities. The simulation results obtained thereof illustrate the bounding domain of variations in some clinically observed details.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13254
- Subject Headings
- Glucose--Metabolism, Computer simulation, Diabetes--Metabolism, Computer modeling
- Format
- Document (PDF)
- Title
- A selectively redundant file system.
- Creator
- Veradt, Joy L., Florida Atlantic University, Fernandez, Eduardo B., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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Disk arrays have been proposed as a means of achieving high performance, reliability and availability in computer systems. This study looks at the RAID (Redundant Array of Inexpensive Disks) disk array architecture and its advantages and disadvantages for use in personal computer environments, specifically in terms of how data is protected (redundant information) and the tradeoff required to achieve that protection (sacrifice of disk capacity). It then proposes an alternative to achieving a...
Show moreDisk arrays have been proposed as a means of achieving high performance, reliability and availability in computer systems. This study looks at the RAID (Redundant Array of Inexpensive Disks) disk array architecture and its advantages and disadvantages for use in personal computer environments, specifically in terms of how data is protected (redundant information) and the tradeoff required to achieve that protection (sacrifice of disk capacity). It then proposes an alternative to achieving a real-time method of protecting a user's data, which involves the modification of an operating system's file system to implement selective redundancy at the file level. This approach, based on modified RAIDs, is shown to be considerably more efficient in using the capacity of the available disks. It also provides flexibility in allowing users to tradeoff space for reliability.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14844
- Subject Headings
- Computer files--Reliability, Systems software--Reliability, Databases--Reliability
- Format
- Document (PDF)
- Title
- A system for assisting in the determination of geometric similarity between machined cylindrical parts.
- Creator
- Lockard, Alan A. L., Florida Atlantic University, Hoffman, Frederick, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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The costs associated with the design and manufacture of machined components can be significantly reduced by the ability to identify and group similar parts. This activity is generally accomplished by assigning each part a Group Technology code number based on its most significant characteristics. Attempts to accomplish this are hindered by: the relatively small amount of information that can be encoded in a code of manageable length, inconsistencies in human interpretation of design and...
Show moreThe costs associated with the design and manufacture of machined components can be significantly reduced by the ability to identify and group similar parts. This activity is generally accomplished by assigning each part a Group Technology code number based on its most significant characteristics. Attempts to accomplish this are hindered by: the relatively small amount of information that can be encoded in a code of manageable length, inconsistencies in human interpretation of design and manufacturing data, the commitment of resources required to review and encode all candidate components at a facility, and the heuristic nature of determining what constitutes significant similarity for any particular application. These problems are addressed by the development of a system that assists in the determination of similarity by comparing CAD (Computer Aided Design) files, rather than Group Technology codes, in a manufacturing oriented frame-based system.
Show less - Date Issued
- 1989
- PURL
- http://purl.flvc.org/fcla/dt/14497
- Subject Headings
- Computer-aided design, Machine parts, Group technology, Manufacturing processes--Data processing
- Format
- Document (PDF)
- Title
- A new GMDH type algorithm for the development of neural networks for pattern recognition.
- Creator
- Gilbar, Thomas C., Florida Atlantic University, Pandya, Abhijit S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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Researchers from a wide range of fields have discovered the benefits of applying neural networks to pattern recognition problems. Although applications for neural networks have increased, development of tools to design these networks has been slower. There are few comprehensive network development methods. Those that do exist are slow, inefficient, and application specific, require predetermination of the final network structure, and/or result in large, complicated networks. Finding optimal...
Show moreResearchers from a wide range of fields have discovered the benefits of applying neural networks to pattern recognition problems. Although applications for neural networks have increased, development of tools to design these networks has been slower. There are few comprehensive network development methods. Those that do exist are slow, inefficient, and application specific, require predetermination of the final network structure, and/or result in large, complicated networks. Finding optimal neural networks that balance low network complexity with accuracy is a complicated process that traditional network development procedures are incapable of achieving. Although not originally designed for neural networks, the Group Method of Data Handling (GMDH) has characteristics that are ideal for neural network design. GMDH minimizes the number of required neurons by choosing and keeping only the best neurons and filtering out unneeded inputs. In addition, GMDH develops the neurons and organizes the network simultaneously, saving time and processing power. However, some of the qualities of the network must still be predetermined. This dissertation introduces a new algorithm that applies some of the best characteristics of GMDH to neural network design. The new algorithm is faster, more flexible, and more accurate than traditional network development methods. It is also more dynamic than current GMDH based methods, capable of creating a network that is optimal for an application and training data. Additionally, the new algorithm virtually guarantees that the number of neurons progressively decreases in each succeeding layer. To show its flexibility, speed, and ability to design optimal networks, the algorithm was used to successfully design networks for a wide variety of real applications. The networks developed using the new algorithm were compared to other development methods and network architectures. The new algorithm's networks were more accurate and yet less complicated than the other networks. Additionally, the algorithm designs neurons that are flexible enough to meet the needs of the specific applications, yet similar enough to be implemented using a standardized hardware cell. When combined with the simplified network layout that naturally occurs with the algorithm, this results in networks that can be implemented using Field Programmable Gate Array (FPGA) type devices.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/11994
- Subject Headings
- GMDH algorithms, Neural networks (Computer science), Pattern recognition systems
- Format
- Document (PDF)
