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Pages
- Title
- Sodium valproate-induced congenital cardiac abnormalities in mice are associated with the inhibition of histone deacetylase.
- Creator
- Wu, Gang, Nan, Changlong, Rollo, Johnathon C, Huang, Xupei, Tian, Jie
- Date Issued
- 2010
- PURL
- http://purl.flvc.org/fau/fd/FAUIR000219
- Format
- Citation
- Title
- Checkpointing schemes for high-performance parallel applications in networks of workstations.
- Creator
- He, Fusen., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
In this thesis, a low interprocessor communication overhead and high performance data parallelism parallel application model in a network of workstations (NOWs) is proposed. Checkpointing and rollback technologies are used in this model for performance enhancement purpose. The proposed model is analyzed both theoretically and numerically. The simulation results show that a high performance of the parallel application model is expected. As a case study, the proposed model is used to the...
Show moreIn this thesis, a low interprocessor communication overhead and high performance data parallelism parallel application model in a network of workstations (NOWs) is proposed. Checkpointing and rollback technologies are used in this model for performance enhancement purpose. The proposed model is analyzed both theoretically and numerically. The simulation results show that a high performance of the parallel application model is expected. As a case study, the proposed model is used to the parallel Everglades Landscape Fire Model (ELFM) code which was developed by South Florida Water Management District (SFWMD). The parallel programming environment is Message-Passing Interface (MPI). A synchronous checkpointing and rollback mechanism is used to handle the spread of fire which is a dynamic and irregular component of the model. Results show that the performance of the parallel ELFM using MPI is significantly enhanced by the application of checkpointing and rollback.
Show less - Date Issued
- 1998
- PURL
- http://purl.flvc.org/fcla/dt/15597
- Subject Headings
- Computer networks, Electronic data processing--Distributed processing, Fault-tolerant computing
- Format
- Document (PDF)
- Title
- Enhanced ticket-based QoS routing protocols in ad hoc networks.
- Creator
- Huang, Chun-Jung, Florida Atlantic University, Wu, Jie
- Abstract/Description
-
This thesis describes QoS routing techniques in ad hoc networks. QoS routing is to find paths between given source and destinations that fulfill a set of QoS requirements. QoS routing in ad hoc networks is a challenging problem due to the dynamical nature of ad hoc networks and the complexity of the QoS routing problem. Ticket-based probing scheme (TBP) is a creative approach to solve QoS routing problem, however, its proactive nature makes it deficient and unscalable. In this thesis, we...
Show moreThis thesis describes QoS routing techniques in ad hoc networks. QoS routing is to find paths between given source and destinations that fulfill a set of QoS requirements. QoS routing in ad hoc networks is a challenging problem due to the dynamical nature of ad hoc networks and the complexity of the QoS routing problem. Ticket-based probing scheme (TBP) is a creative approach to solve QoS routing problem, however, its proactive nature makes it deficient and unscalable. In this thesis, we first present the adaptive ticket-based routing protocol (ATBR), a proactive protocol enhanced from TBP, by introducing a new imprecise QoS state model. We then present the location-aided, ticket-based routing protocol (LTBR), an integration of locate-based routing and ticket-based routing, where tickets are dynamically generated and guided by location and QoS metric. Our simulations show that, in networks under any density, LTBR achieves close performances to flooding with considerably lower routing overhead.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13060, http://purl.flvc.org/fau/fd/FADT13060
- Subject Headings
- Computer network protocols, Mobile computing, Wireless communication systems, Routers (Computer networks)
- Format
- Document (PDF)
- Title
- Energy-efficient routing in ad hoc wireless networks.
- Creator
- Dai, Qing., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
The ad hoc wireless network is an infrastructureless network, where mobile stations are typically powered by batteries. Energy conservation has therefore becomes a very important issue. In this thesis, we discuss our work on several problems in energy-efficient routing. Chapter 3 focuses on how to compute the minimum uniform broadcast transmission power in an ad hoc wireless network. Several algorithms are proposed and their running time compared through simulation. It is shown that Prim's...
Show moreThe ad hoc wireless network is an infrastructureless network, where mobile stations are typically powered by batteries. Energy conservation has therefore becomes a very important issue. In this thesis, we discuss our work on several problems in energy-efficient routing. Chapter 3 focuses on how to compute the minimum uniform broadcast transmission power in an ad hoc wireless network. Several algorithms are proposed and their running time compared through simulation. It is shown that Prim's Minimum Spanning Tree (MST) has better performance than Kruskal's MST and the two binary search algorithms. In the following two chapters, routing algorithms are studied for specific situations, when directional antenna is used (Chapter 4) or when partial signal could be collected, stored and integrated (Chapter 5). Different algorithms are discussed and their energy performance illustrated by simulation study. Their application and limitation are also discussed in the thesis.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13077
- Subject Headings
- Wireless communication systems, Routers (Computer networks), Electronic digital computers--Power supply, Mobile computing
- Format
- Document (PDF)
- Title
- Parallel algorithms for domain load balance.
- Creator
- Huang, Hao., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
To improve the performance of parallel/distributed systems, we propose four parallel load balance algorithms. The new partition algorithm achieves load balance among processors via domain partition. If we assume the problem domain is evenly load distributed, this algorithm will divide the whole domain into a required number of subdomains with the same area. If a problem domain has a dynamic load distribution, although the new partition algorithm is still suitable for the initial mapping, we...
Show moreTo improve the performance of parallel/distributed systems, we propose four parallel load balance algorithms. The new partition algorithm achieves load balance among processors via domain partition. If we assume the problem domain is evenly load distributed, this algorithm will divide the whole domain into a required number of subdomains with the same area. If a problem domain has a dynamic load distribution, although the new partition algorithm is still suitable for the initial mapping, we propose three dynamic load balance algorithms. These dynamic algorithms achieve load balance among processors by transferring load among processors. We applied the new partition algorithm to a specific domain and compared the method to some existing partition algorithms. We also simulated three dynamic load balance algorithms. Results of comparisons and simulations show that all the four algorithms have satisfactory performance.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/15478
- Subject Headings
- Algorithms, Parallel processing (Electronic computers)
- Format
- Document (PDF)
- Title
- Optimal planning of robot calibration experiments by genetic algorithms.
- Creator
- Huang, Weizhen., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
In this thesis work, techniques developed in the science of genetic computing is applied to solve the problem of planning a robot calibration experiment. Robot calibration is a process by the robot accuracy is enhanced through modification of its control software. The selection of robot measurement configurations is an important element in successfully completing a robot calibration experiment. A classical genetic algorithm is first customized for a type of robot measurement configuration...
Show moreIn this thesis work, techniques developed in the science of genetic computing is applied to solve the problem of planning a robot calibration experiment. Robot calibration is a process by the robot accuracy is enhanced through modification of its control software. The selection of robot measurement configurations is an important element in successfully completing a robot calibration experiment. A classical genetic algorithm is first customized for a type of robot measurement configuration selection problem in which the robot workspace constraints are defined in terms of robot joint limits. The genetic parameters are tuned in a systematic way to greatly enhance the performance of the algorithm. A recruit-oriented genetic algorithm is then proposed, together with new genetic operators. Examples are also given to illustrate the concepts of this new genetic algorithm. This new algorithm is aimed at solving another type of configuration selection problem, in which not all points in the robot workspace are measurable by an external measuring device. Extensive simulation studies are conducted for both classical and recruit-oriented genetic algorithms, to examine the effectiveness of these algorithms.
Show less - Date Issued
- 1995
- PURL
- http://purl.flvc.org/fcla/dt/15186
- Subject Headings
- Genetic algorithms, Robots--Calibration, Combinatorial optimization
- Format
- Document (PDF)
- Title
- Reputation-based system for encouraging cooperation of nodes in mobile ad hoc networks.
- Creator
- Anantvalee, Tiranuch., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
In a mobile ad hoc network, node cooperation in packet forwarding is required for the network to function properly. However, since nodes in this network usually have limited resources, some selfish nodes might intend not to forward packets to save resources for their own use. To discourage such behavior, we propose RMS, a reputation-based system, to detect selfish nodes and respond to them by showing that being cooperative will benefit there more than being selfish. We also detect, to some...
Show moreIn a mobile ad hoc network, node cooperation in packet forwarding is required for the network to function properly. However, since nodes in this network usually have limited resources, some selfish nodes might intend not to forward packets to save resources for their own use. To discourage such behavior, we propose RMS, a reputation-based system, to detect selfish nodes and respond to them by showing that being cooperative will benefit there more than being selfish. We also detect, to some degree, nodes who forward only the necessary amount of packets to avoid being detected as selfish. We introduce the use of a state model to decide what we should do or respond to nodes in each state. In addition, we introduce the use of a timing period to control when the reputation should be updated and to use as a timeout for each state. The simulation results show that RMS can identify selfish nodes and punish them accordingly, which provide selfish nodes with an incentive to behave more cooperatively.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13406
- Subject Headings
- Computer networks--Security measures, Wireless communication systems, Routers (Computer networks), Computer network architectures
- Format
- Document (PDF)
- Title
- A class-based search system in unstructured peer-to-peer networks.
- Creator
- Huang, Juncheng., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
Efficient searching is one of the important design issues in peer-to-peer (P2P) networks. Among various searching techniques, semantic-based searching has drawn significant attention recently. Gnutella-like efficient searching system (GES) [29] is such a system. GES derives node vector , a semantic summary of all documents on a node based on vector space model (VSM). The node-based topology adaptation algorithm and search protocol are then discussed. However, when there are many categories of...
Show moreEfficient searching is one of the important design issues in peer-to-peer (P2P) networks. Among various searching techniques, semantic-based searching has drawn significant attention recently. Gnutella-like efficient searching system (GES) [29] is such a system. GES derives node vector , a semantic summary of all documents on a node based on vector space model (VSM). The node-based topology adaptation algorithm and search protocol are then discussed. However, when there are many categories of documents at each node, the node vector representation may be inaccurate. We extend the idea of GES and present a class-based search system (CSS). It makes use of a document clustering algorithm: OSKM [27] to cluster all documents on a node into several classes. Each class can be viewed as a virtual node. As a result, class vector replaces node vector and plays an important role in class-based topology adaptation and search process, which makes CSS very efficient. Our simulation demonstrates that CSS outperforms GES.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13367
- Subject Headings
- Peer-to-peer architecture (Computer networks), Management information systems, Computer security, Cascading style sheets, Web sites--Design
- Format
- Document (PDF)
- Title
- A connected dominating-set-based routing in ad hoc wireless networks.
- Creator
- Gao, Ming., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
In ad hoc wireless networks, routing protocols are challenged with establishing and maintaining multihop routes in the face of mobility, bandwidth limitation and power constraints. Routing based on a connected dominating set is a promising approach, where the searching space for a router reduced to nodes in the set. A set is dominating if all the nodes in the system are either in the dominating set or adjacent to some nodes in the dominating set. In this thesis, we propose a method of...
Show moreIn ad hoc wireless networks, routing protocols are challenged with establishing and maintaining multihop routes in the face of mobility, bandwidth limitation and power constraints. Routing based on a connected dominating set is a promising approach, where the searching space for a router reduced to nodes in the set. A set is dominating if all the nodes in the system are either in the dominating set or adjacent to some nodes in the dominating set. In this thesis, we propose a method of calculating power-aware connected dominating set. Our simulation results show that the proposed approach outperforms several existing approaches in terms of life span of the network. We also discuss mobility management in dominating-set-based networks. Three operations are considered which are mobile host switch on, mobile host switch off and mobile host movement. We also discuss the use of dynamic source routing as an application of the connected dominating set.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12780
- Subject Headings
- Mobile computing, Computer networks, Computer algorithms
- Format
- Document (PDF)
- Title
- Energy-efficient protocols for wireless sensor networks.
- Creator
- Du, Kemei., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
This thesis describes energy-conserving techniques in wireless sensor networks. In wireless sensor networks the sensor nodes gather information and send the information to a base station periodically. Some important messages need be broadcast to all nodes. Due to the limited battery capacity in sensor nodes, energy efficiency is becoming a major challenging problem in these power-constrained networks. Chain-based protocols construct a transmission chain connecting all nodes to save energy...
Show moreThis thesis describes energy-conserving techniques in wireless sensor networks. In wireless sensor networks the sensor nodes gather information and send the information to a base station periodically. Some important messages need be broadcast to all nodes. Due to the limited battery capacity in sensor nodes, energy efficiency is becoming a major challenging problem in these power-constrained networks. Chain-based protocols construct a transmission chain connecting all nodes to save energy dissipation of data transmission. We propose a multiple-chain scheme for all-to-all broadcasting. Furthermore, we develop an energy-efficient chain-construction algorithm which uses a sequence of insertions to minimize the energy consumption along the chain. We propose an energy-based adaptive clustering protocol, in which cluster-head elections depend on not only a probabilistic model but also the remaining energy in each node. This protocol improves the life time of the network by distributing energy usage effectively among the sensor nodes.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12912
- Subject Headings
- Wireless communication systems, Computer network protocols
- Format
- Document (PDF)
- Title
- A reduced overhead routing protocol for ad hoc wireless networks.
- Creator
- Ibriq, Jamil, Florida Atlantic University, Wu, Jie
- Abstract/Description
-
This document describes the Reduced Overhead Routing (ROR) protocol for use in mobile wireless ad hoc networks. The protocol is highly bandwidth-efficient. The protocol has three distinguishing features: First, it maintains, for each destination, multiple paths. Second, routing table updates are localized. Updates are initiated only when the update table is not empty and the update frequency has not exceeded a specified rate. Third, ROR uses threshold routing technique; it allows an...
Show moreThis document describes the Reduced Overhead Routing (ROR) protocol for use in mobile wireless ad hoc networks. The protocol is highly bandwidth-efficient. The protocol has three distinguishing features: First, it maintains, for each destination, multiple paths. Second, routing table updates are localized. Updates are initiated only when the update table is not empty and the update frequency has not exceeded a specified rate. Third, ROR uses threshold routing technique; it allows an intermediate node to deliver data packet via a longer sub-optimal route that is within the distance. To prevent frequent updates, at most one update is initiated every predefined period of time. A node transmits each update with propagation radius that is determined on the basis of node's network region using a novel probabilistic technique. Threshold routing and localized probabilistic updates greatly reduce routing overhead and network congestion and improve bandwidth efficiency.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/12703
- Subject Headings
- Mobile computing, Computer networks, Wireless communication systems
- Format
- Document (PDF)
- Title
- Group structures in object-oriented database authorization.
- Creator
- Fernandez, Minjie Hua., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
When there are a large number and a variety of users in a system, the authorization rules for these users will become too difficult and cumbersome to maintain and the evaluation algorithm would not be efficient. Also, it is hard for security administrators to understand why a specific user is given a set of rights. In this thesis we develop group structures to solve these problems. Groups of users rather than individual users are subjects that receive access rights from the authorization...
Show moreWhen there are a large number and a variety of users in a system, the authorization rules for these users will become too difficult and cumbersome to maintain and the evaluation algorithm would not be efficient. Also, it is hard for security administrators to understand why a specific user is given a set of rights. In this thesis we develop group structures to solve these problems. Groups of users rather than individual users are subjects that receive access rights from the authorization system. We present structurings and primitives for user groups. Although they are presented in the context of an object-oriented database system they are general and could be applied to other data model, and even in operating systems.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14878
- Subject Headings
- Electronic data processing--Security measures, User interfaces (Computer systems)
- Format
- Document (PDF)
- Title
- Time-step optimal broadcasting in mesh networks with minimum total communication distance.
- Creator
- Cang, Songluan., Florida Atlantic University, Wu, Jie
- Abstract/Description
-
We propose a new minimum total communication distance (TCD) algorithm and an optimal TCD algorithm for broadcast in a 2-dimensional mesh (2-D mesh). The former generates a minimum TCD from a given source node, and the latter guarantees a minimum TCD among all the possible source nodes. These algorithms are based on a divide-and-conquer approach where a 2-D mesh is partitioned into four submeshes of equal size. The source node sends the broadcast message to a special node called an eye in each...
Show moreWe propose a new minimum total communication distance (TCD) algorithm and an optimal TCD algorithm for broadcast in a 2-dimensional mesh (2-D mesh). The former generates a minimum TCD from a given source node, and the latter guarantees a minimum TCD among all the possible source nodes. These algorithms are based on a divide-and-conquer approach where a 2-D mesh is partitioned into four submeshes of equal size. The source node sends the broadcast message to a special node called an eye in each submesh. The above procedure is then recursively applied in each submesh. These algorithms are extended to a 3-dimensional mesh (3-D mesh), and are generalized to a d-dimensional mesh or torus. In addition, the proposed approach can potentially be used to solve optimization problems in other collective communication operations.
Show less - Date Issued
- 1999
- PURL
- http://purl.flvc.org/fcla/dt/15647
- Subject Headings
- Computer algorithms, Parallel processing (Electronic computers), Computer architecture
- Format
- Document (PDF)
- Title
- Power-aware broadcasting and activity scheduling in ad hoc wireless networks using connected dominating sets.
- Creator
- Wu, Bing., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In mobile ad hoc wireless networks (MANET), due to host mobility, broadcasting is expected to be frequently used to find a route to a particular host, to page a host, and to alarm all hosts. A straightforward broadcasting by flooding is usually very costly and results in substantial redundancy and more energy consumption. Power consumption is an important issue since most mobile hosts operate on battery. Broadcasting based on a connected dominating set (CDS) is a promising approach, where...
Show moreIn mobile ad hoc wireless networks (MANET), due to host mobility, broadcasting is expected to be frequently used to find a route to a particular host, to page a host, and to alarm all hosts. A straightforward broadcasting by flooding is usually very costly and results in substantial redundancy and more energy consumption. Power consumption is an important issue since most mobile hosts operate on battery. Broadcasting based on a connected dominating set (CDS) is a promising approach, where only nodes inside CDS need to relay the broadcast packet. Wu and Li proposed a simple distributed algorithm for calculating CDS in MANET. In general, nodes inside CDS consume more energy to handle various bypass traffics than nodes outside the set. To prolong the life span of each node and, hence, the network by balancing the energy consumption in the system, nodes should be alternated in being chosen to form a CDS. Activity scheduling deals with the way to rotate the role of each node among a set of given operation modes. In thesis I propose to apply power-aware CDS notions to broadcasting and activity scheduling. I also introduce distance rule and extended rules to further reduce broadcasting energy consumption. The effectiveness of the proposed method are confirmed through my simulation experiment.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12958
- Subject Headings
- Mobile computing, Wireless communication systems, Electronic digital computers--Power supply
- Format
- Document (PDF)
- Title
- Key management in mobile ad hoc networks.
- Creator
- Wu, Bing., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
In mobile ad hoc networks (MANETs), providing secure communications is a big challenge due to unreliable wireless media, host mobility and lack of infrastructure. Usually, cryptographic techniques are used for secure communications in wired networks. Symmetric and asymmetric cryptography have their advantages and disadvantages. In fact, any cryptographic means is ineffective if its key management is weak. Key management is also a central aspect for security in mobile ad hoc networks. In...
Show moreIn mobile ad hoc networks (MANETs), providing secure communications is a big challenge due to unreliable wireless media, host mobility and lack of infrastructure. Usually, cryptographic techniques are used for secure communications in wired networks. Symmetric and asymmetric cryptography have their advantages and disadvantages. In fact, any cryptographic means is ineffective if its key management is weak. Key management is also a central aspect for security in mobile ad hoc networks. In MANETs, the computational load and complexity for key management are strongly subject to restriction by the node's available resources and the dynamic nature of network topology. We proposed a secure and efficient key management framework (SEKM) for MANETs. SEKM builds a PKI by applying a secret sharing scheme and using an underlying multicast server groups. In SEKM, each server group creates a view of the certificate authority (CA) and provides certificate update service for all nodes, including the servers themselves. Motivated by the distributed key management service, we introduced k-Anycast concept and proposed three k-anycast routing schemes for MANETs. k-anycast is proposed to deliver a packet to any threshold k members of a set of hosts. Our goal is to reduce the routing control messages and network delay to reach any k servers. The first scheme is called controlled flooding. The second scheme, called component-based scheme I, is to form multiple components such that each component has at least k members. The third scheme, called component-based scheme II, in which the membership a component maintains is relaxed to be less than k. Collaborative and group-oriented applications in MANETs is an active research area. Group key management is a central building block in securing group communications in MANETs. However, group key management for large and dynamic groups in MANETs is a difficult problem. We propose a simple and efficient group key management scheme that we named SEGK for MANETs, which is based on n-party Diffie-Hellman (DH). The basic idea of our scheme is that a physical multicast tree is formed in MANETs for efficiency. To achieve fault tolerance, double multicast trees are constructed and maintained. A group coordinator computes and distributes intermediate keying materials to all members through multicast tree links. All group members take turns acting as group coordinator and distributing the workload of group rekeying during any change of group membership. Every group member computes the group key in a distributed manner.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/12234
- Subject Headings
- Electronic commerce--Technological innovations, Mobile commerce--Technological innovations, Wireless communication systems--Management, Mobile communication systems--Management
- Format
- Document (PDF)
- Title
- Spatiotemporal expression of histone acetyltransferases, p300 and CBP, in developing embryonic hearts.
- Creator
- Chen, Guozhen, Zhu, Jing, Lv, Tiewei, Wu, Gang, Sun, Hui-Chao, Huang, Xupei, Tian, Jie
- Date Issued
- 2009
- PURL
- http://purl.flvc.org/fau/fd/FAUIR000153
- Format
- Citation
- Title
- Active networking and innovation: An evaluation of active networking as a driver of accelerated Internet innovation.
- Creator
- Wood, James L., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Innovation has flourished at the edge of the Internet; however, the core has experienced a slower pace of innovation. This lag is impacting the pace of innovation at the edge and threatening quality as ad hoc solutions are implemented to overcome core network barriers to innovation. Active networking technology, which opens up the architecture of routers, is proposed as a standard solution. Researchers draw an analogy to the computer industry where innovation is claimed to be accelerated by...
Show moreInnovation has flourished at the edge of the Internet; however, the core has experienced a slower pace of innovation. This lag is impacting the pace of innovation at the edge and threatening quality as ad hoc solutions are implemented to overcome core network barriers to innovation. Active networking technology, which opens up the architecture of routers, is proposed as a standard solution. Researchers draw an analogy to the computer industry where innovation is claimed to be accelerated by modularization. This argument is valid to the extent that the router market is similar to the computer market; however, contemporary innovation theories cast doubt on this likelihood. These theories indicate that for active networking technology to accelerate Internet innovation, extraordinary measures will be required to break the status quo. This paper analyzes this situation and makes recommendations, based on innovation theory, on how active networking can be successful in accelerating Internet innovation.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fcla/dt/13161
- Subject Headings
- Computer industry--Technological innovations, Computer networks--Management, Computer networks--Software, Routers (Computer networks), Internetworking (Telecommunication)
- Format
- Document (PDF)
- Title
- Dynamic routing in grid-connected networks.
- Creator
- Jiang, Zhen., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
This dissertation describes the effect of collection and distribution of fault information on routing capacity in grid-connected networks with faults occurring during the routing process. The grid-connected network, such as hypercubes, 2-D meshes, and 3-D meshes, is one of the simplest and least expensive structures to build a system using hundreds and even thousands of processors. In such a system, efficient communication among the processors is critical to performance. Hence, the routing of...
Show moreThis dissertation describes the effect of collection and distribution of fault information on routing capacity in grid-connected networks with faults occurring during the routing process. The grid-connected network, such as hypercubes, 2-D meshes, and 3-D meshes, is one of the simplest and least expensive structures to build a system using hundreds and even thousands of processors. In such a system, efficient communication among the processors is critical to performance. Hence, the routing of messages is an important issue that needs to be addressed. As the number of nodes in the networks increases, the chance of failure also increases. The complex nature of networks also makes them vulnerable to disturbances. Therefore, the ability to route messages efficiently in the presence of faulty components, especially those might occur during the routing process, is becoming increasingly important. A central issue in designing a fault-tolerant routing algorithm is the way fault information is collected and used. The safety level model is a special coded fault information model in hypercubes which is more cost effective and more efficient than other information models. In this model, each node is associated with an integer, called safety level, which is an approximated measure of the number and distribution of faulty nodes in the neighborhood. The safety level of each node in an n-dimensional hypercube can be easily calculated through (n - 1)-rounds information exchanges among neighboring nodes. A k-safe node indicates the existence of at least one Hamming distance path (also called optimal path or minimal path) from this node to any node with Hamming distance k. We focus on routing capacity using safety levels in a dynamic system. In this case, the update of safety levels and the routing process proceed hand-in-hand. During the converging period, the routing process may experience extra hops based on unstable (inconsistent) information. Under the assumption that the total number of faults is less than n, we provide an upper bound of extra hops and show its accuracy and effectiveness. After that, we extend the results to meshes. Our simulation results show the effectiveness of our information model and scalability of our fault-information-based routing in the grid-connected networks with dynamic faults. Because our information is easy to update and maintain and optimality is still preserved, it is more cost effective than the others.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12002
- Subject Headings
- Fault-tolerant computing, Hypercube networks (Computer networks)
- Format
- Document (PDF)
- Title
- Efficient localized broadcast algorithms in mobile ad hoc networks.
- Creator
- Lou, Wei., Florida Atlantic University, Wu, Jie, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
The broadcast operation has a most fundamental role in mobile ad hoc networks because of the broadcasting nature of radio transmission, i.e., when a sender transmits a packet, all nodes within the sender's transmission range will be affected by this transmission. The benefit of this property is that one packet can be received by all neighbors while the negative effect is that it interferes with other transmissions. Flooding ensures that the entire network receives the packet but generates...
Show moreThe broadcast operation has a most fundamental role in mobile ad hoc networks because of the broadcasting nature of radio transmission, i.e., when a sender transmits a packet, all nodes within the sender's transmission range will be affected by this transmission. The benefit of this property is that one packet can be received by all neighbors while the negative effect is that it interferes with other transmissions. Flooding ensures that the entire network receives the packet but generates many redundant transmissions which may trigger a serious broadcast storm problem that may collapse the entire network. The broadcast storm problem can be avoided by providing efficient broadcast algorithms that aim to reduce the number of nodes that retransmit the broadcast packet while still guaranteeing that all nodes receive the packet. This dissertation focuses on providing several efficient localized broadcast algorithms to reduce the broadcast redundancy in mobile ad hoc networks. In my dissertation, the efficiency of a broadcast algorithm is measured by the number of forward nodes for relaying a broadcast packet. A classification of broadcast algorithms for mobile ad hoc networks has been provided at the beginning. Two neighbor-designating broadcast algorithms, called total dominant pruning and partial dominant pruning, have been proposed to reduce the number of the forward nodes. Several extensions based on the neighbor-designating approach have also been investigated. The cluster-based broadcast algorithm shows good performance in dense networks, and it also provides a constant upper bound approximation ratio to the optimum solution for the number of forward nodes in the worst case. A generic broadcast framework with K hop neighbor information has a trade-off between the number of the forward nodes and the size of the K-hop zone. A reliable broadcast algorithm, called double-covered broadcast, is proposed to improve the delivery ratio of a broadcast package when the transmission error rate of the network is high. The effectiveness of all these algorithms has been confirmed by simulations.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fau/fd/FADT12103
- Subject Headings
- Wireless LANS, Mobile communication systems, Wireless communication systems--Mathematics, Algorithms
- Format
- Document (PDF)
- Title
- Efficient and Effective Searching m Unstructured FileSharing Peer-to-Peer Networks.
- Creator
- Li, Xiuqi, Wu, Jie, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
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Peer-to-peer (P2P) networking has been receiving increasing attention from the research community recently. How to conduct efficient and effective searching in such networks has been a challenging research topic. This dissertation focuses on unstructured file-sharing peer-to-peer networks. Three novel searching schemes are proposed, implemented, and evaluated. In the first scheme named ISRL (Intelligent Search by Reinforcement Learning), we propose to systematically learn the best route to...
Show morePeer-to-peer (P2P) networking has been receiving increasing attention from the research community recently. How to conduct efficient and effective searching in such networks has been a challenging research topic. This dissertation focuses on unstructured file-sharing peer-to-peer networks. Three novel searching schemes are proposed, implemented, and evaluated. In the first scheme named ISRL (Intelligent Search by Reinforcement Learning), we propose to systematically learn the best route to desired files through reinforcement learning when topology adaptation is impossible or infeasible. To discover the best path to desired files, ISRL not only explores new paths by forwarding queries to randomly chosen neighbors, but also exploits the paths that have been discovered for reducing the cumulative query cost. Three models of ISRL are put forwarded: a basic version for finding one desired file, MP-ISRL (MP stands for Multiple-Path ISRL) for finding at least k files, and C-ISRL (C refers to Clustering) for reducing maintenance overhead through clustering when there are many queries. ISRL outperforms existing searching approaches in unstructured peer-to-peer networks by achieving similar query quality with lower cumulative query cost. The experimental results confirm the performance improvement of ISRL. The second approach, HS-SDBF (Hint-based Searching by Scope Decay Bloom Filter), addresses the issue of effective and efficient hint propagation. We design a new data structure called SDBF (Scope Decay Bloom Filter) to represent and advertise probabilistic hints. Compared to existing proactive schemes, HSSDBF can answer many more queries successfully at a lower amortized cost considering both the query traffic and hint propagation traffic. Both the analytic and the experimental results support the performance improvement of our protocol. The third algorithm, hybrid search, seeks to combine the benefits of both forwarding and non-forwarding searching schemes. In this approach, a querying source directly probes its own extended neighbors and forwards a query to a subset of its extended neighbors and guides these neighbors to probe their own extended neighbors on its behalf. The hybrid search is able to adapt query execution to the popularity of desired files without generating too much state maintenance overhead because of the 1-hop forwarding inherent in the approach. It achieves a higher query efficiency than the forwarding scheme and a better success rate than the non-forwarding approach. To the best of our knowledge, this work is the first attempt to integrate forwarding and non-forwarding schemes. Simulation results demonstrate the effectiveness of the hybrid search.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fau/fd/FA00012572
- Subject Headings
- Peer-to-peer architecture (Computer networks), Computer security, Database searching, Internetworking (Telecommunication), Heterogeneous computing
- Format
- Document (PDF)
