Current Search: Department of Computer and Electrical Engineering and Computer Science (x) » Computer algorithms (x)
View All Items
Pages
- Title
- Routing in mobile ad-hoc wireless networks.
- Creator
- Li, Hailan., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This thesis describes routing in mobile ad hoc wireless networks. Ad hoc networks are lack of wired backbone to maintain routes as mobile hosts move and power is on or off. Therefore, the hosts in ad hoc networks must cooperate with each other to determine routes in a distributed manner. Routing based on a connected dominating set is a frequently used approach, where the searching space for a route is reduced to nodes in small connected dominating set subnetwork. We propose a simple and...
Show moreThis thesis describes routing in mobile ad hoc wireless networks. Ad hoc networks are lack of wired backbone to maintain routes as mobile hosts move and power is on or off. Therefore, the hosts in ad hoc networks must cooperate with each other to determine routes in a distributed manner. Routing based on a connected dominating set is a frequently used approach, where the searching space for a route is reduced to nodes in small connected dominating set subnetwork. We propose a simple and efficient distributed algorithm for calculating connected dominating set in a given un-directed ad hoc network, then evaluate the proposed algorithm through simulation. We also discuss connected dominating set update/recalculation algorithms when the topology of the ad hoc network changes. We also explore the possible extension of using hierarchical connected dominating set. The shortest path routing and the dynamic source routing, which are based on the connected dominating set subnetwork, are discussed.
Show less - Date Issued
- 1999
- PURL
- http://purl.flvc.org/fcla/dt/15695
- Subject Headings
- Mobile computing, Computer algorithms, Computer networks
- Format
- Document (PDF)
- Title
- Design and implementation of efficient routing protocols in delay tolerant networks.
- Creator
- Liu, Cong., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Delay tolerant networks (DTNs) are occasionally-connected networks that may suffer from frequent partitions. DTNs provide service despite long end to end delays or infrequent connectivity. One fundamental problem in DTNs is routing messages from their source to their destination. DTNs differ from the Internet in that disconnections are the norm instead of the exception. Representative DTNs include sensor-based networks using scheduled intermittent connectivity, terrestrial wireless networks...
Show moreDelay tolerant networks (DTNs) are occasionally-connected networks that may suffer from frequent partitions. DTNs provide service despite long end to end delays or infrequent connectivity. One fundamental problem in DTNs is routing messages from their source to their destination. DTNs differ from the Internet in that disconnections are the norm instead of the exception. Representative DTNs include sensor-based networks using scheduled intermittent connectivity, terrestrial wireless networks that cannot ordinarily maintain end-to-end connectivity, satellite networks with moderate delays and periodic connectivity, underwater acoustic networks with moderate delays and frequent interruptions due to environmental factors, and vehicular networks with cyclic but nondeterministic connectivity. The focus of this dissertation is on routing protocols that send messages in DTNs. When no connected path exists between the source and the destination of the message, other nodes may relay the message to the destination. This dissertation covers routing protocols in DTNs with both deterministic and non-deterministic mobility respectively. In DTNs with deterministic and cyclic mobility, we proposed the first routing protocol that is both scalable and delivery guaranteed. In DTNs with non-deterministic mobility, numerous heuristic protocols are proposed to improve the routing performance. However, none of those can provide a theoretical optimization on a particular performance measurement. In this dissertation, two routing protocols for non-deterministic DTNs are proposed, which minimizes delay and maximizes delivery rate on different scenarios respectively. First, in DTNs with non-deterministic and cyclic mobility, an optimal single-copy forwarding protocol which minimizes delay is proposed., In DTNs with non-deterministic mobility, an optimal multi-copy forwarding protocol is proposed. which maximizes delivery rate under the constraint that the number of copies per message is fixed . Simulation evaluations using both real and synthetic trace are conducted to compare the proposed protocols with the existing ones.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/210522
- Subject Headings
- Computer network protocols, Computer networks, Reliability, Computer algorithms, Wireless communication systems, Technological innovations
- Format
- Document (PDF)
- Title
- A utility-based routing scheme in multi-hop wireless networks.
- Creator
- Lu, Mingming., College of Engineering and Computer Science, Florida Atlantic University, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Multi-hop wireless networks are infrastructure-less networks consisting of mobile or stationary wireless devices, which include multi-hop wireless mesh networks and multi-hop wireless sensor networks. These networks are characterized by limited bandwidth and energy resources, unreliable communication, and a lack of central control. These characteristics lead to the research challenges of multi-hop wireless networks. Building up routing schemes with good balance among the routing QoS (such as...
Show moreMulti-hop wireless networks are infrastructure-less networks consisting of mobile or stationary wireless devices, which include multi-hop wireless mesh networks and multi-hop wireless sensor networks. These networks are characterized by limited bandwidth and energy resources, unreliable communication, and a lack of central control. These characteristics lead to the research challenges of multi-hop wireless networks. Building up routing schemes with good balance among the routing QoS (such as reliability, cost, and delay) is a paramount concern to achieve high performance wireless networks. These QoS metrics are internally correlated. Most existing works did not fully utilize this correlation. We design a metric to balance the trade-off between reliability and cost, and build up a framework of utility-based routing model in multi-hop wireless networks. This dissertation focuses on the variations with applications of utility-based routing models, designing new concepts, and developing new algorithms for them. A review of existing routing algorithms and the basic utility-based routing model for multi-hop wireless networks has been provided at the beginning. An efficient algorithm, called MaxUtility, has been proposed for the basic utility-based routing model. MaxUtility is an optimal algorithm that can find the best routing path with the maximum expected utility., Various utility-based routing models are extended to further enhance the routing reliability while reducing the routing overhead. Besides computing the optimal path for a given benefit value and a given source-destination pair, the utility-based routing can be further extended to compute all optimal paths for all possible benefit values and/or all source-destination pairs. Our utility-based routing can also adapt to different applications and various environments. In the self-organized environment, where network users are selfish, we design a truthful routing, where selfish users have to tell the truth in order to maximize their utilities. We apply our utility-based routing scheme to the data-gathering wireless sensor networks, where a routing scheme is required to transmit data sensed by multiple sensor nodes to a common sink node.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/77647
- Subject Headings
- Wireless communication systems, Security measures, Computer network protocols, Computer algorithms, Computer networks, Security measures
- Format
- Document (PDF)
- Title
- Probabilistic predictor-based routing in disruption-tolerant networks.
- Creator
- Yuan, Quan., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Disruption-Tolerant Networks (DTNs) are the networks comprised of a set of wireless nodes, and they experience unstable connectivity and frequent connection disruption because of the limitations of radio range, power, network density, device failure, and noise. DTNs are characterized by their lack of infrastructure, device limitation, and intermittent connectivity. Such characteristics make conventional wireless network routing protocols fail, as they are designed with the assumption the...
Show moreDisruption-Tolerant Networks (DTNs) are the networks comprised of a set of wireless nodes, and they experience unstable connectivity and frequent connection disruption because of the limitations of radio range, power, network density, device failure, and noise. DTNs are characterized by their lack of infrastructure, device limitation, and intermittent connectivity. Such characteristics make conventional wireless network routing protocols fail, as they are designed with the assumption the network stays connected. Thus, routing in DTNs becomes a challenging problem, due to the temporal scheduling element in a dynamic topology. One of the solutions is prediction-based, where nodes mobility is estimated with a history of observations. Then, the decision of forwarding messages during data delivery can be made with that predicted information. Current prediction-based routing protocols can be divided into two sub-categories in terms of that whether they are probability related: probabilistic and non-probabilistic. This dissertation focuses on the probabilistic prediction-based (PPB) routing schemes in DTNs. We find that most of these protocols are designed for a specified topology or scenario. So almost every protocol has some drawbacks when applied to a different scenario. Because every scenario has its own particular features, there could hardly exist a universal protocol which can suit all of the DTN scenarios. Based on the above motivation, we investigate and divide the current DTNs scenarios into three categories: Voronoi-based, landmark-based, and random moving DTNs. For each category, we design and implement a corresponding PPB routing protocol for either basic routing or a specified application with considering its unique features., Specifically, we introduce a Predict and Relay routing protocol for Voronoi-based DTNs, present a single-copy and a multi-copy PPB routing protocol for landmark-based DTNs, and propose DRIP, a dynamic Voronoi region-based publish/subscribe protocol, to adapt publish/subscribe systems to random moving DTNs. New concepts, approaches, and algorithms are introduced during our work.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/359928
- Subject Headings
- Routers (Computer networks), Computer network protocols, Computer networks, Reliability, Computer algorithms, Wireless communication systems, Technological innovations
- Format
- Document (PDF)
- Title
- Connected Dominating Set in Wireless Ad Hoc Networks: Variations with Applications.
- Creator
- Yang, Shuhui, Wu, Jie, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Wireless ad hoc networks (or simply ad hoc networks) are infrastructureless multihop networks consisting of mobile or stationary wireless devices, which include mobile ad hoc networks (MANETs) and wireless sensor networks (WSNs). These networks are characterized by limited bandwidth and energy resources, frequent topology changes, and a lack of central control. These characteristics lead to the research challenges of ad hoc networks. The algorithms designed for ad hoc networks should be...
Show moreWireless ad hoc networks (or simply ad hoc networks) are infrastructureless multihop networks consisting of mobile or stationary wireless devices, which include mobile ad hoc networks (MANETs) and wireless sensor networks (WSNs). These networks are characterized by limited bandwidth and energy resources, frequent topology changes, and a lack of central control. These characteristics lead to the research challenges of ad hoc networks. The algorithms designed for ad hoc networks should be localized, selforganizing, and energy efficient. A connected dominating set (CDS) is frequently used in ad hoc networks as a virtual backbone to support efficient routing, service discovery, and area monitoring. In addition, efficient broadcasting (i.e., finding a small set of forward nodes to ensure full delivery) can be viewed as forming a CDS on-the-fly. The periodically maintained virtual backbone is called a static CDS, and the temporarily formed forward node set is called a dynamk CDS. For efficiency and robustness, the ideal CDS construction algorithm is lightweight, has fast convergence, and minimizes the CDS size. Recently, due to some specific applications and new techniques, the concept of a connected dominating set can be modified or further extended for more efficient usage. This dissertation focuses on the variations with applications of the connected dominating set, designing new concepts, and developing new algorithms for them. A review of CDS construction algorithms for ad hoc networks has been provided at the beginning. An efficient scheme, called Rule K, has been proposed for static CDS construction. Rule K achieves a probabilistic constant upper bound on the expected CDS size, which is currently the best known performance guarantee for localized CDS algorithms. Several CDS algorithms are extended to generate the extended CDS, which exploits the cooperative communication technique to further reduce the size of CDS. A k-coverage set is developed for higher robustness. With the equipment of directional antennas , the transmission can be restricted to some certain directions to reduce interference and energy consumption. The corresponding directional CDS is discussed. Finally, a wireless sensor and actor network (WSAN) is introduced and localized algorithms are designed for it.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00012580
- Subject Headings
- Computer network protocols, Wireless communication systems--Design and construction, Mobile computing, Computer algorithms
- Format
- Document (PDF)
- Title
- Binary representation of DNA sequences towards developing useful algorithms in bioinformatic data-mining.
- Creator
- Pandya, Shivani., Florida Atlantic University, Neelakanta, Perambur S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This thesis refers to a research addressing the use of binary representation of the DNA for the purpose of developing useful algorithms for Bioinformatics. Pertinent studies address the use of a binary form of the DNA base chemicals in information-theoretic base so as to identify symmetry between DNA and complementary DNA. This study also refers to "fuzzy" (codon-noncodon) considerations in delinating codon and noncodon regimes in a DNA sequences. The research envisaged further includes a...
Show moreThis thesis refers to a research addressing the use of binary representation of the DNA for the purpose of developing useful algorithms for Bioinformatics. Pertinent studies address the use of a binary form of the DNA base chemicals in information-theoretic base so as to identify symmetry between DNA and complementary DNA. This study also refers to "fuzzy" (codon-noncodon) considerations in delinating codon and noncodon regimes in a DNA sequences. The research envisaged further includes a comparative analysis of the test results on the aforesaid efforts using different statistical metrics such as Hamming distance Kullback-Leibler measure etc. the observed details supports the symmetry aspect between DNA and CDNA strands. It also demonstrates capability of identifying non-codon regions in DNA even under diffused (overlapped) fuzzy states.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13089
- Subject Headings
- Bioinformatics, Data mining, Nucleotide sequence--Databases, Computer algorithms
- Format
- Document (PDF)
- Title
- Quality of service support in TDMA-based mobile ad hoc networks.
- Creator
- Jawhar, Imad., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
With the continuing advances in computing and wireless technologies, mobile ad hoc networks (MANETs) are expected to become an indispensable part of the computing environment in the near future. Wireless devices are constantly growing in computing speed, memory, communication capabilities and features, while shrinking in weight and size. With this growth and the proliferation of these devices in every aspect of society, the need for such devices to communicate in a seamless manner is becoming...
Show moreWith the continuing advances in computing and wireless technologies, mobile ad hoc networks (MANETs) are expected to become an indispensable part of the computing environment in the near future. Wireless devices are constantly growing in computing speed, memory, communication capabilities and features, while shrinking in weight and size. With this growth and the proliferation of these devices in every aspect of society, the need for such devices to communicate in a seamless manner is becoming increasingly essential. Multiple routing protocols have been developed for MANETs [51]. As MANETs gain popularity, their need to support real time and multimedia applications is growing as well. Such applications have stringent quality of service (QoS) requirements such as bandwidth, delay, and delay fitter. Design and development of routing algorithms with QoS support is experiencing increased research interest. Several approaches which propose various routing algorithms with QoS support for MANETs have been presented in research. This dissertation addresses the issues and challenges of QoS routing in MANETS and presents three new protocols which provide QoS support for this environment. First, a brief classification of existing QoS routing algorithms is provided. Then, the three new protocols for QoS routing support in MANETs are presented. These protocols focus on resource reservation for QoS provisioning in TDMA-based MANETs. The first protocol improves QoS support by eliminating racing conditions during multiple reservations of QoS paths. The second protocol is a new protocol for resource reservation for QoS support in TDMA-based MANETs using directional antennas. The last protocol provides dynamic range resource reservation for QoS support in MANETs and represents an extension of the previous protocols.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/12158
- Subject Headings
- Digital communications, Time division multiple access, Computer algorithms, Computer network protocols, Wireless communication systems
- Format
- Document (PDF)
- Title
- Fault-tolerant routing in two-dimensional and three-dimensional meshes.
- Creator
- Chen, Xiao., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Mesh-connected multicomputers are one of the simplest and least expensive structures to build a system using hundreds and even thousands of processors. The nodes communicate with each other by sending and receiving messages. As the system gets larger and larger, it not only requires the routing algorithms be efficient but also fault-tolerant. The fault model we use in 2-D meshes is a faulty block while in 3-D meshes, the fault model is a faculty cube. In order to route messages through...
Show moreMesh-connected multicomputers are one of the simplest and least expensive structures to build a system using hundreds and even thousands of processors. The nodes communicate with each other by sending and receiving messages. As the system gets larger and larger, it not only requires the routing algorithms be efficient but also fault-tolerant. The fault model we use in 2-D meshes is a faulty block while in 3-D meshes, the fault model is a faculty cube. In order to route messages through feasible minimum paths, the extended safety level is used to determine the existence of a minimal path and faulty block (cube) information is used to guide the routing. This dissertation presents an in-depth study of fault-tolerant minimal routing in 2-D tori, 3-D meshes, and tree-based fault-tolerant multicasting in 2-D and 3-D meshes using extended safety levels. Also path-based fault-tolerant deadlock-free multicasting in 2-D and 3-D meshes is studied. In fault-tolerant minimal routing in 2-D meshes, if no faulty block is encountered, any adaptive minimal routing can be used until the message encounters a faulty block. The next step is guided by the faulty block information until the message gets away from the faulty block. After that, any minimal adaptive routing can be used again. The minimal routing in 2-D tori is similar to that in 2-D meshes if at the beginning of the routing a conversion is made from a 2-D torus to a 2-D mesh. The fault-tolerant minimal routing in 3-D meshes can be done in a similar way. In the tree-based multicasting in 2-D and 3-D meshes, a time-step optimal and traffic-step suboptimal algorithm is proposed. Several heuristic strategies are presented to resolve a conflict, which are compared by simulations. A path-based fault-tolerant deadlock-free multicast algorithm in 2-D meshes with inter-block distance of at least three is presented to solve the deadlock problem in tree-based multicast algorithms. The approach is then extended to 3-D meshes and to inter-block distance of at least two in 2-D meshes. The path is Hamiltonian that is only updated locally in the neighborhood of a faulty block when a faulty block is encountered. Two virtual channels are used to prevent deadlock in 2-D and 3-D meshes with inter-block (inter-cube) distance of at least three and two more virtual channels are added if the inter-block distance is at least two.
Show less - Date Issued
- 1999
- PURL
- http://purl.flvc.org/fcla/dt/12597
- Subject Headings
- Fault-tolerant computing, Computer algorithms
- Format
- Document (PDF)
- Title
- Label routing protocol: A new cross-layer protocol for multi-hop ad hoc wireless network.
- Creator
- Wang, Yu., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Compared to the traditional wireless network, the multi-hop ad hoc wireless network (simply called ad hoc networks) is self-configurable, dynamic, and distributed. During the past few years, many routing protocols have been proposed for this particular network environment. While in wired and optical networks, multi-protocol label switching (MPLS) has clearly shown its advantages in routing and switching such as flexibility, high efficiency, scalability, and low cost, however MPLS is complex...
Show moreCompared to the traditional wireless network, the multi-hop ad hoc wireless network (simply called ad hoc networks) is self-configurable, dynamic, and distributed. During the past few years, many routing protocols have been proposed for this particular network environment. While in wired and optical networks, multi-protocol label switching (MPLS) has clearly shown its advantages in routing and switching such as flexibility, high efficiency, scalability, and low cost, however MPLS is complex and does not consider the mobility issue for wireless networks, especially for ad hoc networks. This thesis migrates the label concept into the ad hoc network and provides a framework for the efficient Label Routing Protocol (LRP) in such a network. The MAC layer is also optimized with LRP for shorter delay, power saving, and higher efficiency. The simulation results show that the delay is improved significantly with this cross-layer routing protocol.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13321
- Subject Headings
- Computer network protocols, Wireless communication systems, Mobile computing, Computer algorithms, MPLS standard, Operating systems (Computers)
- Format
- Document (PDF)
- Title
- Mobility pattern-based routing algorithm for mobile ad hoc wireless networks.
- Creator
- Vyas, Nirav., Florida Atlantic University, Mahgoub, Imad, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This thesis describes routing in mobile ad hoc wireless networks. Ad hoc networks lack wired backbone to maintain routes as mobile hosts move and power is on or off. Therefore, the hosts in ad hoc networks must cooperate with each other to determine routes in a distributed manner. Routing based on a Location is a frequently used approach, where the searching space for a route is reduced to smaller zone by defining request zone and expected zone. We propose a mobility pattern based algorithm...
Show moreThis thesis describes routing in mobile ad hoc wireless networks. Ad hoc networks lack wired backbone to maintain routes as mobile hosts move and power is on or off. Therefore, the hosts in ad hoc networks must cooperate with each other to determine routes in a distributed manner. Routing based on a Location is a frequently used approach, where the searching space for a route is reduced to smaller zone by defining request zone and expected zone. We propose a mobility pattern based algorithm to reduce the overhead, then evaluate the proposed algorithm through simulation. We have implemented two mobility patterns into Location Aided Routing, namely, leading movement and random walk type mobility patterns. We have developed simulation model for each mobility pattern, using SES/Workbench. The performance is measured in terms of overhead of the network. We also discuss various routing algorithms such as dynamic source routing, zone routing protocol, associativity based routing protocol and ad hoc on demand distance vector routing.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/12662
- Subject Headings
- Mobile computing, Wireless communication systems, Computer algorithms
- Format
- Document (PDF)
- Title
- Mechanisms for prolonging network lifetime in wireless sensor networks.
- Creator
- Yang, Yinying., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Sensors are used to monitor and control the physical environment. A Wireless Sen- sor Network (WSN) is composed of a large number of sensor nodes that are densely deployed either inside the phenomenon or very close to it [18][5]. Sensor nodes measure various parameters of the environment and transmit data collected to one or more sinks, using hop-by-hop communication. Once a sink receives sensed data, it processes and forwards it to the users. Sensors are usually battery powered and it is...
Show moreSensors are used to monitor and control the physical environment. A Wireless Sen- sor Network (WSN) is composed of a large number of sensor nodes that are densely deployed either inside the phenomenon or very close to it [18][5]. Sensor nodes measure various parameters of the environment and transmit data collected to one or more sinks, using hop-by-hop communication. Once a sink receives sensed data, it processes and forwards it to the users. Sensors are usually battery powered and it is hard to recharge them. It will take a limited time before they deplete their energy and become unfunctional. Optimizing energy consumption to prolong network lifetime is an important issue in wireless sensor networks. In mobile sensor networks, sensors can self-propel via springs [14], wheels [20], or they can be attached to transporters, such as robots [20] and vehicles [36]. In static sensor networks with uniform deployment (uniform density), sensors closest to the sink will die first, which will cause uneven energy consumption and limitation of network life- time. In the dissertation, the nonuniform density is studied and analyzed so that the energy consumption within the monitored area is balanced and the network lifetime is prolonged. Several mechanisms are proposed to relocate the sensors after the initial deployment to achieve the desired density while minimizing the total moving cost. Using mobile relays for data gathering is another energy efficient approach. Mobile sensors can be used as ferries, which carry data to the sink for static sensors so that expensive multi-hop communication and long distance communication are reduced. In this thesis, we propose a mobile relay based routing protocol that considers both energy efficiency and data delivery delay. It can be applied to both event-based reporting and periodical report applications., Another mechanism used to prolong network lifetime is sensor scheduling. One of the major components that consume energy is the radio. One method to conserve energy is to put sensors to sleep mode when they are not actively participating in sensing or data relaying. This dissertation studies sensor scheduling mechanisms for composite event detection. It chooses a set of active sensors to perform sensing and data relaying, and all other sensors go to sleep to save energy. After some time, another set of active sensors is chosen. Thus sensors work alternatively to prolong network lifetime.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/1870693
- Subject Headings
- Wireless communication systems, Technological innovations, Wireless communication systems, Design and construction, Ad hoc networks (Computer networks), Technological innovations, Sensor networks, Design and construction, Computer algorithms, Computer network protocols
- Format
- Document (PDF)
- Title
- Comparison of different realizations and adaptive algorithms for channel equalization.
- Creator
- Kamath, Anuradha K., Florida Atlantic University, Sudhakar, Raghavan, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This thesis presents simulation results comparing the performance of different realizations and adaptive algorithms for channel equalization. An attempt is made to study and compare the performance of some filter structures used as an equalizer in fast data transmission over the baseband channel. To this end, simulation experiments are performed using minimum and non minimum phase channel models with adaptation algorithms such as the least mean square (LMS) and recursive least square (RLS)...
Show moreThis thesis presents simulation results comparing the performance of different realizations and adaptive algorithms for channel equalization. An attempt is made to study and compare the performance of some filter structures used as an equalizer in fast data transmission over the baseband channel. To this end, simulation experiments are performed using minimum and non minimum phase channel models with adaptation algorithms such as the least mean square (LMS) and recursive least square (RLS) algorithms, filter structures such as the lattice and transversal filters and the input signals such as the binary phase shift keyed (BPSK) and quadrature phase shift keyed (QPSK) signals. Based on the simulation studies, conclusions are drawn regarding the performance of various adaptation algorithms.
Show less - Date Issued
- 1993
- PURL
- http://purl.flvc.org/fcla/dt/14974
- Subject Headings
- Computer algorithms, Data transmission systems, Equalizers (Electronics)
- Format
- Document (PDF)
- Title
- Embedding binomial trees in faulty hypercube multiprocessors.
- Creator
- Luo, Yinqiu., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
We study the embedding of binomial trees with variable roots in faulty hypercubes. Based on novel embedding strategies, we propose three embedding algorithms with variable nodes as the root. The first algorithm can tolerate up to n - 1 faulty links, but the execution can be done within log2(n - 1) subcube splits. The second one can tolerate up to [(3(n - 1))\2] faulty links. The last one can tolerate up to [(3(n - 4))\2] faulty nodes.
- Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/15345
- Subject Headings
- Hypercube networks (Computer networks), Trees (Graph theory), Multiprocessors, Parallel processing (Electronic computers), Computer algorithms, Fault-tolerant computing, Embedded computer systems
- Format
- Document (PDF)
- Title
- Efficient Resource Discovery Technique in a Mobile Ad Hoc Networks.
- Creator
- Thanawala, Ravi, Wu, Jie, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This thesis describes a resource discovery technique in mobile ad hoc networks. Resource discovery is technique to search data in among the mobile nodes in the network. The highly dynamic nature of the infrastructure-less ad hoc networks poses new challenges in resource discovery, thus there is a need to for an optimized resource discovery technique. Efficient resource discovery algorithm discovers the resources in a mobile ad-hoc network in an optimized way. As there is no pre-established...
Show moreThis thesis describes a resource discovery technique in mobile ad hoc networks. Resource discovery is technique to search data in among the mobile nodes in the network. The highly dynamic nature of the infrastructure-less ad hoc networks poses new challenges in resource discovery, thus there is a need to for an optimized resource discovery technique. Efficient resource discovery algorithm discovers the resources in a mobile ad-hoc network in an optimized way. As there is no pre-established infrastructure in the network, every node takes its decision in forwarding resources and every node dynamically ranks these resources before disseminating them in the network. Ranking of the resources spreads the data which is of high priority at that instance of time. Ranking avoids the spreads the unwanted or low priority data which will utilize the bandwidth unnecessarily. The efficient resource discovery algorithm also keeps a check that redundant information is not spread in the network with the available bandwidth and the bandwidth is utilized in an optimized manner. We then introduce brokers in the algorithm for a better performance. We present a technique to maintain a constant number of brokers in the network. Our simulations show that, in a network with high density, the efficient resource discovery algorithm gives a better performance than the flooding and rank based broadcast algorithms.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fau/fd/FA00012562
- Subject Headings
- Mobile communication systems--Mathematics, Computer algorithms, Wireless communication systems--Mathematics, Ad hoc networks (Computer networks)--Programming
- Format
- Document (PDF)
- Title
- Methods and Algorithms for Human Detection in Video Sequences.
- Creator
- Pertuz, Carlos, Marques, Oge, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Lower prices of video sensors, security concerns and the need for better and faster algorithms to extract high level information from video sequences are all factors which have stimulated research in the area of automated video surveillance systems. In the context of security the analysis of human interrelations and their environment provides hints to proactively identify anomalous behavior. However, human detection is a necessary component in systems where the automatic extraction of higher...
Show moreLower prices of video sensors, security concerns and the need for better and faster algorithms to extract high level information from video sequences are all factors which have stimulated research in the area of automated video surveillance systems. In the context of security the analysis of human interrelations and their environment provides hints to proactively identify anomalous behavior. However, human detection is a necessary component in systems where the automatic extraction of higher level information, such as recognizing individuals' activities, is required. The human detection problem is one of classification. In general, motion, appearance and shape are the classification approaches a system can employ to perform human detection. Techniques representative of these approaches, such us periodic motion detection, skin color detection and MPEG-7 shape descriptors are implemented in this work. An infrastructure that allows data collection for such techniques was also implemented.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00012538
- Subject Headings
- MPEG (Video coding standard), Image processing--Digital techniques, Form perception, Computer algorithms, Video compression
- Format
- Document (PDF)
- Title
- Multi-Path Intelligent Virtual Mobile Nodes for Ad Hoc Networks.
- Creator
- Qian, Binbin, Wu, Jie, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In mobile ad hoc networks, it is challenging to solve the standard problems encountered in fixed network because of the unpredictable motion of mobile nodes. Due to the lack of a fixed infrastructure to serve as the backbone of the network, it is difficult to manage nodes' locations and ensure the stable node performance. The virtual mobile node (VMN) abstraction that has been applied implements an virtual mobile node that consists of a set of real nodes traveling on one predetermined virtual...
Show moreIn mobile ad hoc networks, it is challenging to solve the standard problems encountered in fixed network because of the unpredictable motion of mobile nodes. Due to the lack of a fixed infrastructure to serve as the backbone of the network, it is difficult to manage nodes' locations and ensure the stable node performance. The virtual mobile node (VMN) abstraction that has been applied implements an virtual mobile node that consists of a set of real nodes traveling on one predetermined virtual path to collect messages and deliver them to the destinations when they meet. It conquers the unpredictable motion with virtual nodes' predictable motion. But it encounters unavoidable failure when all the nodes leave the VMN region and stop emulating the VMN. We extend the idea of the VMN abstraction to the Multi-path Intelligent Virtual Mobile Node (MIVMN) abstraction, which allows the messages to switch between multiple Hamiltonian paths to increase the message delivery ratio and decrease the failure rate of the virtual nodes. Through simulation results we show that the MIVMN abstraction successfully meets our goals.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00012542
- Subject Headings
- Routers (Computer networks), Computer network architectures, Wireless communication systems, Computer algorithms
- Format
- Document (PDF)
- Title
- Achieving Higher Receiver Satisfaction using Multicast-Favored Bandwidth Allocation Protocols.
- Creator
- Yousefizadeh, Hooman, Zilouchian, Ali, Ilyas, Mohammad, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In recent years, many protocols for efficient Multicasting have been proposed. However, many of the Internet Service Providers (ISPs) are reluctant to use multicastenabled routers in their networks. To provide such incentives, new protocols are needed to improve the quality of their services. The challenge is to find a compromise between allocating Bandwidth (BW) among different flows in a fair manner, and favoring multicast sessions over unicast sessions. In addition, the overall higher...
Show moreIn recent years, many protocols for efficient Multicasting have been proposed. However, many of the Internet Service Providers (ISPs) are reluctant to use multicastenabled routers in their networks. To provide such incentives, new protocols are needed to improve the quality of their services. The challenge is to find a compromise between allocating Bandwidth (BW) among different flows in a fair manner, and favoring multicast sessions over unicast sessions. In addition, the overall higher level of receiver satisfaction should be achieved. In this dissertation, we propose three new innovative protocols to favor multicast sessions over unicast sessions. Multicast Favored BW Allocation- Logarithmic (MFBA-Log) and Multicast Favored BW Allocation-Linear (MFBALin) protocols allocate BW proportional to the number of down stream receivers. The proposed Multicast Reserved BW Allocation (MRBA) protocol allocates part of the BW in the links only to multicast sessions. Simulation results show the increase in the overall level of Receiver Satisfaction in the network.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fau/fd/FA00012581
- Subject Headings
- Multicasting (Computer networks), Computer network protocols, Computer algorithms
- Format
- Document (PDF)
- Title
- Application level intrusion detection using a sequence learning algorithm.
- Creator
- Dong, Yuhong., Florida Atlantic University, Hsu, Sam, Rajput, Saeed, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
An un-supervised learning algorithm on application level intrusion detection, named Graph Sequence Learning Algorithm (GSLA), is proposed in this dissertation. Experiments prove its effectiveness. Similar to most intrusion detection algorithms, in GSLA, the normal profile needs to be learned first. The normal profile is built using a session learning method, which is combined with the one-way Analysis of Variance method (ANOVA) to determine the value of an anomaly threshold. In the proposed...
Show moreAn un-supervised learning algorithm on application level intrusion detection, named Graph Sequence Learning Algorithm (GSLA), is proposed in this dissertation. Experiments prove its effectiveness. Similar to most intrusion detection algorithms, in GSLA, the normal profile needs to be learned first. The normal profile is built using a session learning method, which is combined with the one-way Analysis of Variance method (ANOVA) to determine the value of an anomaly threshold. In the proposed approach, a hash table is used to store a sparse data matrix in triple data format that is collected from a web transition log instead of an n-by-n dimension matrix. Furthermore, in GSLA, the sequence learning matrix can be dynamically changed according to a different volume of data sets. Therefore, this approach is more efficient, easy to manipulate, and saves memory space. To validate the effectiveness of the algorithm, extensive simulations have been conducted by applying the GSLA algorithm to the homework submission system at our computer science and engineering department. The performance of GSLA is evaluated and compared with traditional Markov Model (MM) and K-means algorithms. Specifically, three major experiments have been done: (1) A small data set is collected as a sample data, and is applied to GSLA, MM, and K-means algorithms to illustrate the operation of the proposed algorithm and demonstrate the detection of abnormal behaviors. (2) The Random Walk-Through sampling method is used to generate a larger sample data set, and the resultant anomaly score is classified into several clusters in order to visualize and demonstrate the normal and abnormal behaviors with K-means and GSLA algorithms. (3) Multiple professors' data sets are collected and used to build the normal profiles, and the ANOVA method is used to test the significant difference among professors' normal profiles. The GSLA algorithm can be made as a module and plugged into the IDS as an anomaly detection system.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/12220
- Subject Headings
- Data mining, Parallel processing (Electronic computers), Computer algorithms, Computer security, Pattern recognition systems
- Format
- Document (PDF)
- Title
- Determination of receptive fields in neural networks using Alopex.
- Creator
- Shah, Gaurang G., Florida Atlantic University, Pandya, Abhijit S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This research aims at proposing a model for visual pattern recognition inspired by the neural circuitry in the brain. Our attempt is to propose few modifications in the Alopex algorithm and try to use it for the calculations of the receptive fields of neurons in the trained network. We have developed a small-scale, four-layered neural network model for simple character recognition as well as complex image patterns, which can recognize the patterns transformed by affine conversion. Here Alopex...
Show moreThis research aims at proposing a model for visual pattern recognition inspired by the neural circuitry in the brain. Our attempt is to propose few modifications in the Alopex algorithm and try to use it for the calculations of the receptive fields of neurons in the trained network. We have developed a small-scale, four-layered neural network model for simple character recognition as well as complex image patterns, which can recognize the patterns transformed by affine conversion. Here Alopex algorithm is presented as an iterative and stochastic processing method, which was proposed for optimization of a given cost function over hundreds or thousands of iterations. In this case the receptive fields of the neurons in the output layers are obtained using the Alopex algorithm.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13298
- Subject Headings
- Pattern recognition systems, Neural networks (Computer science), Computer algorithms, Neuroanatomy, Image processing
- Format
- Document (PDF)
- Title
- Complexity metrics in parallel computing.
- Creator
- Larrondo-Petrie, Maria M., Florida Atlantic University, Fernandez, Eduardo B., Coulter, Neal S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Accompanying the potential increase in power offered by parallel computers is an increase in the complexity of program design, implementation, testing and maintenance. It is important to understand the logical complexity of parallel programs in order to support the development of concurrent software. Measures are needed to quantify the components of parallel software complexity and to establish a basis for comparison and analysis of parallel algorithms at various stages of development and...
Show moreAccompanying the potential increase in power offered by parallel computers is an increase in the complexity of program design, implementation, testing and maintenance. It is important to understand the logical complexity of parallel programs in order to support the development of concurrent software. Measures are needed to quantify the components of parallel software complexity and to establish a basis for comparison and analysis of parallel algorithms at various stages of development and implementation. A set of primitive complexity measures is proposed that collectively describe the total complexity of parallel programs. The total complexity is separated into four dimensions or components: requirements, sequential, parallel and communication. Each proposed primitive measure is classified under one of these four areas. Two additional possible dimensions, fault-tolerance and real-time, are discussed. The total complexity measure is expressed as a vector of dimensions; each component is defined as a vector of primitive metrics. The method of quantifying each primitive metric is explained in detail. Those primitive metrics that contribute to the parallel and communications complexity are exercised against ten published summation algorithms and programs, illustrating that architecture has a significant effect on the complexity of parallel programs--even if the same programming language is used. The memory organization and the processor interconnection scheme had no effect on the parallel component, but did affect the communication component. Programming style and language did not have a noticeable effect on either component. The proposed metrics are quantifiable, consistent, and useful in comparing parallel algorithms. Unlike existing parallel metrics, they are general and applicable to different languages, architectures, algorithms, paradigms, programming styles and stages of software development.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/12296
- Subject Headings
- Parallel programming (Computer Science), Computer algorithms
- Format
- Document (PDF)