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- Title
- RESOURCE ALLOCATION SCHEMES AND PERFORMANCE EVALUATION MODELS FOR WAVELENGTH DIVISION MULTIPLEXED OPTICAL NETWORKS.
- Creator
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El Houmaidi, Mounire, Bassiouni, Mostafa, University of Central Florida
- Abstract / Description
-
Wavelength division multiplexed (WDM) optical networks are rapidly becoming the technology of choice in network infrastructure and next-generation Internet architectures. WDM networks have the potential to provide unprecedented bandwidth, reduce processing cost, achieve protocol transparency, and enable efficient failure handling. This dissertation addresses the important issues of improving the performance and enhancing the reliability of WDM networks as well as modeling and evaluating the...
Show moreWavelength division multiplexed (WDM) optical networks are rapidly becoming the technology of choice in network infrastructure and next-generation Internet architectures. WDM networks have the potential to provide unprecedented bandwidth, reduce processing cost, achieve protocol transparency, and enable efficient failure handling. This dissertation addresses the important issues of improving the performance and enhancing the reliability of WDM networks as well as modeling and evaluating the performance of these networks. Optical wavelength conversion is one of the emerging WDM enabling technologies that can significantly improve bandwidth utilization in optical networks. A new approach for the sparse placement of full wavelength converters based on the concept of the k-Dominating Set (k-DS) of a graph is presented. The k-DS approach is also extended to the case of limited conversion capability using three scalable and cost-effective switch designs: flexible node-sharing, strict node-sharing and static mapping. Compared to full search algorithms previously proposed in the literature, the K-DS approach has better blocking performance, has better time complexity and avoids the local minimum problem. The performance benefit of the K-DS approach is demonstrated by extensive simulation. Fiber delay line (FDL) is another emerging WDM technology that can be used to obtain limited optical buffering capability. A placement algorithm, k-WDS, for the sparse placement of FDLs at a set of selected nodes in Optical Burst Switching (OBS) networks is proposed. The algorithm can handle both uniform and non-uniform traffic patterns. Extensive performance tests have shown that k-WDS provides more efficient placement of optical fiber delay lines than the well-known approach of placing the resources at nodes with the highest experienced burst loss. Performance results that compare the benefit of using FDLs versus using optical wavelength converters (OWCs) are presented. A new algorithm, A-WDS, for the placement of an arbitrary numbers of FDLs and OWCs is introduced and is evaluated under different non-uniform traffic loads. This dissertation also introduces a new cost-effective optical switch design using FDL and a QoS-enhanced JET (just enough time) protocol suitable for optical burst switched WDM networks. The enhanced JET protocol allows classes of traffic to benefit from FDLs and OWCs while minimizing the end-to-end delay for high priority bursts. Performance evaluation models of WDM networks represent an important research area that has received increased attention. A new analytical model that captures link dependencies in all-optical WDM networks under uniform traffic is presented. The model enables the estimation of connection blocking probabilities more accurately than previously possible. The basic formula of the dependency between two links in this model reflects their degree of adjacency, the degree of connectivity of the nodes composing them and their carried traffic. The usefulness of the model is illustrated by applying it to the sparse wavelength converters placement problem in WDM networks. A lightpath containing converters is divided into smaller sub-paths such that each sub-path is a wavelength continuous path and the nodes shared between these sub-paths are full wavelength conversion capable. The blocking probability of the entire path is obtained by computing the blocking probabilities of the individual sub-paths. The analytical-based sparse placement algorithm is validated by comparing it with its simulation-based counterpart using a number of network topologies. Rapid recovery from failure and high levels of reliability are extremely important in WDM networks. A new Fault Tolerant Path Protection scheme, FTPP, for WDM mesh networks based on the alarming state of network nodes and links is introduced. The results of extensive simulation tests show that FTPP outperforms known path protection schemes in terms of loss of service ratio and network throughput. The simulation tests used a wide range of values for the load intensity, the failure arrival rate and the failure holding time. The FTPP scheme is next extended to the differentiated services model and its connection blocking performance is evaluated. Finally, a QoS-enhanced FTPP (QEFTPP) routing and path protection scheme in WDM networks is presented. QEFTPP uses preemption to minimize the connection blocking percentage for high priority traffic. Extensive simulation results have shown that QEFTPP achieves a clear QoS differentiation among the traffic classes and provides a good overall network performance.
Show less - Date Issued
- 2005
- Identifier
- CFE0000346, ucf:46291
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000346
- Title
- MEDIUM ACCESS CONTROL PROTOCOLS AND ROUTING ALGORITHMS FOR WIRELESS SENSOR NETWORKS.
- Creator
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Bag, Anirban, Bassiouni, Mostafa, University of Central Florida
- Abstract / Description
-
In recent years, the development of a large variety of mobile computing devices has led to wide scale deployment and use of wireless ad hoc and sensor networks. Wireless Sensor Networks consist of battery powered, tiny and cheap "motes", having sensing and wireless communication capabilities. Although wireless motes have limited battery power, communication and computation capabilities, the range of their application is vast. In the first part of the dissertation, we have addressed the...
Show moreIn recent years, the development of a large variety of mobile computing devices has led to wide scale deployment and use of wireless ad hoc and sensor networks. Wireless Sensor Networks consist of battery powered, tiny and cheap "motes", having sensing and wireless communication capabilities. Although wireless motes have limited battery power, communication and computation capabilities, the range of their application is vast. In the first part of the dissertation, we have addressed the specific application of Biomedical Sensor Networks. To solve the problem of data routing in these networks, we have proposed the Adaptive Least Temperature Routing (ALTR) algorithm that reduces the average temperature rise of the nodes in the in-vivo network while routing data efficiently. For delay sensitive biomedical applications, we proposed the Hotspot Preventing Routing (HPR) algorithm which avoids the formation of hotspots (regions having very high temperature) in the network. HPR forwards the packets using the shortest path, bypassing the regions of high temperature and thus significantly reduces the average packet delivery delay, making it suitable for real-time applications of in-vivo networks. We also proposed another routing algorithm suitable for being used in a network of id-less biomedical sensor nodes, namely Routing Algorithm for networks of homogeneous and Id-less biomedical sensor Nodes (RAIN). Finally we developed Biocomm, a cross-layer MAC and Routing protocol co-design for Biomedical Sensor Networks, which optimizes the overall performance of an in-vivo network through cross-layer interactions. We performed extensive simulations to show that the proposed Biocomm protocol performs much better than the other existing MAC and Routing protocols in terms of preventing the formation of hotspots, reducing energy consumption of nodes and preventing network congestion when used in an in-vivo network. In the second part of the dissertation, we have addressed the problems of habitat-monitoring sensor networks, broadcast algorithms for sensor networks and the congestion problem in sensor networks as well as one non-sensor network application, namely, on-chip communication networks. Specifically, we have proposed a variation of HPR algorithm, called Hotspot Preventing Adaptive Routing (HPAR) algorithm, for efficient data routing in Networks On-Chip catering to their specific hotspot prevention issues. A protocol similar to ALTR has been shown to perform well in a sensor network deployed for habitat monitoring. We developed a reliable, low overhead broadcast algorithm for sensor networks namely Topology Adaptive Gossip (TAG) algorithm. To reduce the congestion problem in Wireless Sensor Networks, we proposed a tunable cross-layer Congestion Reducing Medium Access Control (CRMAC) protocol that utilizes buffer status information from the Network layer to give prioritized medium access to congested nodes in the MAC layer and thus preventing congestion and packet drops. CRMAC can also be easily tuned to satisfy different application-specific performance requirements. With the help of extensive simulation results we have shown how CRMAC can be adapted to perform well in different applications of Sensor Network like Emergency Situation that requires a high network throughput and low packet delivery latency or Long-term Monitoring application requiring energy conservation.
Show less - Date Issued
- 2007
- Identifier
- CFE0001915, ucf:47480
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001915
- Title
- IMPROVING ROUTING EFFICIENCY, FAIRNESS, DIFFERENTIATED SERVISES AND THROUGHPUT IN OPTICAL NETWORKS.
- Creator
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ZHOU, BIN, Bassiouni, Mostafa, University of Central Florida
- Abstract / Description
-
Wavelength division multiplexed (WDM) optical networks are rapidly becoming the technology of choice in next-generation Internet architectures. This dissertation addresses the important issues of improving four aspects of optical networks, namely, routing efficiency, fairness, differentiated quality of service (QoS) and throughput. A new approach for implementing efficient routing and wavelength assignment in WDM networks is proposed and evaluated. In this approach, the state of a multiple...
Show moreWavelength division multiplexed (WDM) optical networks are rapidly becoming the technology of choice in next-generation Internet architectures. This dissertation addresses the important issues of improving four aspects of optical networks, namely, routing efficiency, fairness, differentiated quality of service (QoS) and throughput. A new approach for implementing efficient routing and wavelength assignment in WDM networks is proposed and evaluated. In this approach, the state of a multiple-fiber link is represented by a compact bitmap computed as the logical union of the bitmaps of the free wavelengths in the fibers of this link. A modified Dijkstra's shortest path algorithm and a wavelength assignment algorithm are developed using fast logical operations on the bitmap representation. In optical burst switched (OBS) networks, the burst dropping probability increases as the number of hops in the lightpath of the burst increases. Two schemes are proposed and evaluated to alleviate this unfairness. The two schemes have simple logic, and alleviate the beat-down unfairness problem without negatively impacting the overall throughput of the system. Two similar schemes to provide differentiated services in OBS networks are introduced. A new scheme to improve the fairness of OBS networks based on burst preemption is presented. The scheme uses carefully designed constraints to avoid excessive wasted channel reservations, reduce cascaded useless preemptions, and maintain healthy throughput levels. A new scheme to improve the throughput of OBS networks based on burst preemption is presented. An analytical model is developed to compute the throughput of the network for the special case when the network has a ring topology and the preemption weight is based solely on burst size. The analytical model is quite accurate and gives results close to those obtained by simulation. Finally, a preemption-based scheme for the concurrent improvement of throughput and burst fairness in OBS networks is proposed and evaluated. The scheme uses a preemption weight consisting of two terms: the first term is a function of the size of the burst and the second term is the product of the hop count times the length of the lightpath of the burst.
Show less - Date Issued
- 2006
- Identifier
- CFE0001019, ucf:46811
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001019
- Title
- DESIGN AND ANALYSIS OF EFFECTIVE ROUTING AND CHANNEL SCHEDULING FOR WAVELENGTH DIVISION MULTIPLEXING OPTICAL NETWORKS.
- Creator
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Gao, Xingbo, Bassiouni, Mostafa, University of Central Florida
- Abstract / Description
-
Optical networking, employing wavelength division multiplexing (WDM), is seen as the technology of the future for the Internet. This dissertation investigates several important problems affecting optical circuit switching (OCS) and optical burst switching (OBS) networks. Novel algorithms and new approaches to improve the performance of these networks through effective routing and channel scheduling are presented. Extensive simulations and analytical modeling have both been used to evaluate...
Show moreOptical networking, employing wavelength division multiplexing (WDM), is seen as the technology of the future for the Internet. This dissertation investigates several important problems affecting optical circuit switching (OCS) and optical burst switching (OBS) networks. Novel algorithms and new approaches to improve the performance of these networks through effective routing and channel scheduling are presented. Extensive simulations and analytical modeling have both been used to evaluate the effectiveness of the proposed algorithms in achieving lower blocking probability, better fairness as well as faster switching. The simulation tests were performed over a variety of optical network topologies including the ring and mesh topologies, the U.S. Long-Haul topology, the Abilene high-speed optical network used in Internet 2, the Toronto Metropolitan topology and the European Optical topology. Optical routing protocols previously published in the literature have largely ignored the noise and timing jitter accumulation caused by cascading several wavelength conversions along the lightpath of the data burst. This dissertation has identified and evaluated a new constraint, called the wavelength conversion cascading constraint. According to this constraint, the deployment of wavelength converters in future optical networks will be constrained by a bound on the number of wavelength conversions that a signal can go through when it is switched all-optically from the source to the destination. Extensive simulation results have conclusively demonstrated that the presence of this constraint causes significant performance deterioration in existing routing and wavelength assignment (RWA) algorithms. Higher blocking probability and/or worse fairness have been observed for existing RWA algorithms when the cascading constraint is not ignored. To counteract the negative side effect of the cascading constraint, two constraint-aware routing algorithms are proposed for OCS networks: the desirable greedy algorithm and the weighted adaptive algorithm. The two algorithms perform source routing using link connectivity and the global state information of each wavelength. Extensive comparative simulation results have illustrated that by limiting the negative cascading impact to the minimum extent practicable, the proposed approaches can dramatically decrease the blocking probability for a variety of optical network topologies. The dissertation has developed a suite of three fairness-improving adaptive routing algorithms in OBS networks. The adaptive routing schemes consider the transient link congestion at the moment when bursts arrive and use this information to reduce the overall burst loss probability. The proposed schemes also resolve the intrinsic unfairness defect of existing popular signaling protocols. The extensive simulation results have shown that the proposed schemes generally outperform the popular shortest path routing algorithm and the improvement could be substantial. A two-dimensional Markov chain analytical model has also been developed and used to analyze the burst loss probabilities for symmetrical ring networks. The accuracy of the model has been validated by simulation. Effective proactive routing and preemptive channel scheduling have also been proposed to address the conversion cascading constraint in OBS environments. The proactive routing adapts the fairness-improving adaptive routing mentioned earlier to the environment of cascaded wavelength conversions. On the other hand, the preemptive channel scheduling approach uses a dynamic priority for each burst based on the constraint threshold and the current number of performed wavelength conversions. Empirical results have proved that when the cascading constraint is present, both approaches would not only decrease the burst loss rates greatly, but also improve the transmission fairness among bursts with different hop counts to a large extent.
Show less - Date Issued
- 2009
- Identifier
- CFE0002965, ucf:47958
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002965
- Title
- A NEW FRAMEWORK FOR QOS PROVISIONING IN WIRELESS LANS USING THE P-PERSISTENT MAC PROTOCOL.
- Creator
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Anna, Kiran Babu, Bassiouni, Mostafa, University of Central Florida
- Abstract / Description
-
The support of multimedia traffic over IEEE 802.11 wireless local area networks (WLANs) has recently received considerable attention. This dissertation has proposed a new framework that provides efficient channel access, service differentiation and statistical QoS guarantees in the enhanced distributed channel access (EDCA) protocol of IEEE 802.11e. In the first part of the dissertation, the new framework to provide QoS support in IEEE 802.11e is presented. The framework uses three...
Show moreThe support of multimedia traffic over IEEE 802.11 wireless local area networks (WLANs) has recently received considerable attention. This dissertation has proposed a new framework that provides efficient channel access, service differentiation and statistical QoS guarantees in the enhanced distributed channel access (EDCA) protocol of IEEE 802.11e. In the first part of the dissertation, the new framework to provide QoS support in IEEE 802.11e is presented. The framework uses three independent components, namely, a core MAC layer, a scheduler, and an admission control. The core MAC layer concentrates on the channel access mechanism to improve the overall system efficiency. The scheduler provides service differentiation according to the weights assigned to each Access Category (AC). The admission control provides statistical QoS guarantees. The core MAC layer developed in this dissertation employs a P-Persistent based MAC protocol. A weight-based fair scheduler to obtain throughput service differentiation at each node has been used. In wireless LANs (WLANs), the MAC protocol is the main element that determines the efficiency of sharing the limited communication bandwidth of the wireless channel. In the second part of the dissertation, analytical Markov chain models for the P-Persistent 802.11 MAC protocol under unsaturated load conditions with heterogeneous loads are developed. The Markov models provide closed-form formulas for calculating the packet service time, the packet end-to-end delay, and the channel capacity in the unsaturated load conditions. The accuracy of the models has been validated by extensive NS2 simulation tests and the models are shown to give accurate results. In the final part of the dissertation, the admission control mechanism is developed and evaluated. The analytical model for P-Persistent 802.11 is used to develop a measurement-assisted model-based admission control. The proposed admission control mechanism uses delay as an admission criterion. Both distributed and centralized admission control schemes are developed and the performance results show that both schemes perform very efficiently in providing the QoS guarantees. Since the distributed admission scheme control does not have a complete state information of the WLAN, its performance is generally inferior to the centralized admission control scheme. The detailed performance results using the NS2 simulator have demonstrated the effectiveness of the proposed framework. Compared to 802.11e EDCA, the scheduler consistently achieved the desired throughput differentiation and easy tuning. The core MAC layer achieved better delays in terms of channel access, average packet service time and end-to-end delay. It also achieved higher system throughput than EDCA for any given service differentiation ratio. The admission control provided the desired statistical QoS guarantees.
Show less - Date Issued
- 2010
- Identifier
- CFE0003243, ucf:48513
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003243
- Title
- Correctness and Progress Verification of Non-Blocking Programs.
- Creator
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Peterson, Christina, Dechev, Damian, Leavens, Gary, Bassiouni, Mostafa, Cash, Mason, University of Central Florida
- Abstract / Description
-
The progression of multi-core processors has inspired the development of concurrency libraries that guarantee safety and liveness properties of multiprocessor applications. The difficulty of reasoning about safety and liveness properties in a concurrent environment has led to the development of tools to verify that a concurrent data structure meets a correctness condition or progress guarantee. However, these tools possess shortcomings regarding the ability to verify a composition of data...
Show moreThe progression of multi-core processors has inspired the development of concurrency libraries that guarantee safety and liveness properties of multiprocessor applications. The difficulty of reasoning about safety and liveness properties in a concurrent environment has led to the development of tools to verify that a concurrent data structure meets a correctness condition or progress guarantee. However, these tools possess shortcomings regarding the ability to verify a composition of data structure operations. Additionally, verification techniques for transactional memory evaluate correctness based on low-level read/write histories, which is not applicable to transactional data structures that use a high-level semantic conflict detection.In my dissertation, I present tools for checking the correctness of multiprocessor programs that overcome the limitations of previous correctness verification techniques. Correctness Condition Specification (CCSpec) is the first tool that automatically checks the correctness of a composition of concurrent multi-container operations performed in a non-atomic manner. Transactional Correctness tool for Abstract Data Types (TxC-ADT) is the first tool that can check the correctness of transactional data structures. TxC-ADT elevates the standard definitions of transactional correctness to be in terms of an abstract data type, an essential aspect for checking correctness of transactions that synchronize only for high-level semantic conflicts. Many practical concurrent data structures, transactional data structures, and algorithms to facilitate non-blocking programming all incorporate helping schemes to ensure that an operation comprising multiple atomic steps is completed according to the progress guarantee. The helping scheme introduces additional interference by the active threads in the system to achieve the designed progress guarantee. Previous progress verification techniques do not accommodate loops whose termination is dependent on complex behaviors of the interfering threads, making these approaches unsuitable. My dissertation presents the first progress verification technique for non-blocking algorithms that are dependent on descriptor-based helping mechanisms.
Show less - Date Issued
- 2019
- Identifier
- CFE0007705, ucf:52433
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007705
- Title
- Scalable Network Design and Management with Decentralized Software-defined Networking.
- Creator
-
Atwal, Kuldip Singh, Bassiouni, Mostafa, Fu, Xinwen, Zou, Changchun, Deo, Narsingh, University of Central Florida
- Abstract / Description
-
Network softwarization is among the most significant innovations of computer networks in the last few decades. The lack of uniform and programmable interfaces for network management led to the design of OpenFlow protocol for the university campuses and enterprise networks. This breakthrough coupled with other similar efforts led to an emergence of two complementary but independent paradigms called software-defined networking (SDN) and network function virtualization (NFV). As of this writing,...
Show moreNetwork softwarization is among the most significant innovations of computer networks in the last few decades. The lack of uniform and programmable interfaces for network management led to the design of OpenFlow protocol for the university campuses and enterprise networks. This breakthrough coupled with other similar efforts led to an emergence of two complementary but independent paradigms called software-defined networking (SDN) and network function virtualization (NFV). As of this writing, these paradigms are becoming the de-facto norms of wired and wireless networks alike. This dissertation mainly addresses the scalability aspect of SDN for multiple network types. Although centralized control and separation of control and data planes play a pivotal role for ease of network management, these concepts bring in many challenges as well. Scalability is among the most crucial challenges due to the unprecedented growth of computer networks in the past few years. Therefore, we strive to grapple with this problem in diverse networking scenarios and propose novel solutions by harnessing capabilities provided by SDN and other related technologies. Specifically, we present the techniques to deploy SDN at the Internet scale and to extend the concepts of softwarization for mobile access networks and vehicular networks. Multiple optimizations are employed to mitigate latency and other overheads that contribute to achieve performance gains. Additionally, by taking care of sparse connectivity and high mobility, the intrinsic constraints of centralization for wireless ad-hoc networks are addressed in a systematic manner. The state-of-the-art virtualization techniques are coupled with cloud computing methods to exploit the potential of softwarization in general and SDN in particular. Finally, by tapping into the capabilities of machine learning techniques, an SDN-based solution is proposed that inches closer towards the longstanding goal of self-driving networks. Extensive experiments performed on a large-scale testbed corroborates effectiveness of our approaches.
Show less - Date Issued
- 2019
- Identifier
- CFE0007600, ucf:52543
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007600
- Title
- Modeling Crowd Mobility and Communication in Wireless Networks.
- Creator
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Solmaz, Gurkan, Turgut, Damla, Bassiouni, Mostafa, Guha, Ratan, Goldiez, Brian, University of Central Florida
- Abstract / Description
-
This dissertation presents contributions to the fields of mobility modeling, wireless sensor networks (WSNs) with mobile sinks, and opportunistic communication in theme parks. The two main directions of our contributions are human mobility models and strategies for the mobile sink positioning and communication in wireless networks.The first direction of the dissertation is related to human mobility modeling. Modeling the movement of human subjects is important to improve the performance of...
Show moreThis dissertation presents contributions to the fields of mobility modeling, wireless sensor networks (WSNs) with mobile sinks, and opportunistic communication in theme parks. The two main directions of our contributions are human mobility models and strategies for the mobile sink positioning and communication in wireless networks.The first direction of the dissertation is related to human mobility modeling. Modeling the movement of human subjects is important to improve the performance of wireless networks with human participants and the validation of such networks through simulations. The movements in areas such as theme parks follow specific patterns that are not taken into consideration by the general purpose mobility models. We develop two types of mobility models of theme park visitors. The first model represents the typical movement of visitors as they are visiting various attractions and landmarks of the park. The second model represents the movement of the visitors as they aim to evacuate the park after a natural or man-made disaster.The second direction focuses on the movement patterns of mobile sinks and their communication in responding to various events and incidents within the theme park. When an event occurs, the system needs to determine which mobile sink will respond to the event and its trajectory. The overall objective is to optimize the event coverage by minimizing the time needed for the chosen mobile sink to reach the incident area. We extend this work by considering the positioning problem of mobile sinks and preservation of the connected topology. We propose a new variant of p-center problem for optimal placement and communication of the mobile sinks. We provide a solution to this problem through collaborative event coverage of the WSNs with mobile sinks. Finally, we develop a network model with opportunistic communication for tracking the evacuation of theme park visitors during disasters. This model involves people with smartphones that store and carry messages. The mobile sinks are responsible for communicating with the smartphones and reaching out to the regions of the emergent events.
Show less - Date Issued
- 2015
- Identifier
- CFE0006005, ucf:51024
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006005
- Title
- Resource Management in Large-scale Systems.
- Creator
-
Paya, Ashkan, Marinescu, Dan, Wocjan, Pawel, Bassiouni, Mostafa, Mucciolo, Eduardo, University of Central Florida
- Abstract / Description
-
The focus of this thesis is resource management in large-scale systems. Our primary concerns are energy management and practical principles for self-organization and self-management. The main contributions of our work are:1. Models. We proposed several models for different aspects of resource management, e.g., energy-aware load balancing and application scaling for the cloud ecosystem, hierarchical architecture model for self-organizing and self-manageable systems and a new cloud delivery...
Show moreThe focus of this thesis is resource management in large-scale systems. Our primary concerns are energy management and practical principles for self-organization and self-management. The main contributions of our work are:1. Models. We proposed several models for different aspects of resource management, e.g., energy-aware load balancing and application scaling for the cloud ecosystem, hierarchical architecture model for self-organizing and self-manageable systems and a new cloud delivery model based on auction-driven self-organization approach.2. Algorithms. We also proposed several different algorithms for the models described above. Algorithms such as coalition formation, combinatorial auctions and clustering algorithm for scale-free organizations of scale-free networks.3. Evaluation. Eventually we conducted different evaluations for the proposed models and algorithms in order to verify them. All the simulations reported in this thesis had been carried out on different instances and services of Amazon Web Services (AWS).All of these modules will be discussed in detail in the following chapters respectively.
Show less - Date Issued
- 2015
- Identifier
- CFE0005862, ucf:50913
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005862
- Title
- Performance Evaluation of TCP Multihoming for IPV6 Anycast Networks and Proxy Placement.
- Creator
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Alsharfa, Raya, Bassiouni, Mostafa, Guha, Ratan, Lin, Mingjie, University of Central Florida
- Abstract / Description
-
In this thesis, the impact of multihomed clients and multihomed proxy servers on the performance of modern networks is investigated. The network model used in our investigation integrates three main components: the new one-to-any Anycast communication paradigm that facilitates server replication, the next generation Internet Protocol Version 6 (IPv6) that offers larger address space for packet switched networks, and the emerging multihoming trend of connecting devices and smart phones to more...
Show moreIn this thesis, the impact of multihomed clients and multihomed proxy servers on the performance of modern networks is investigated. The network model used in our investigation integrates three main components: the new one-to-any Anycast communication paradigm that facilitates server replication, the next generation Internet Protocol Version 6 (IPv6) that offers larger address space for packet switched networks, and the emerging multihoming trend of connecting devices and smart phones to more than one Internet service provider thereby acquiring more than one IP address. The design of a previously proposed Proxy IP Anycast service is modified to integrate user device multihoming and Ipv6 routing. The impact of user device multihoming (single-homed, dual-homed, and triple-homed) on network performance is extensively analyzed using realistic network topologies and different traffic scenarios of client-server TCP flows. Network throughput, packet latency delay and packet loss rate are the three performance metrics used in our analysis. Performance comparisons between the Anycast Proxy service and the native IP Anycast protocol are presented. The number of Anycast proxy servers and their placement are studied. Five placement methods have been implemented and evaluated including random placement, highest traffic placement, highest number of active interface placements, K-DS placement and a new hybrid placement method. The work presented in this thesis provides new insight into the performance of some new emerging communication paradigms and how to improve their design. Although the work has been limited to investigating Anycast proxy servers, the results can be beneficial and applicable to other types of overlay proxy services such as multicast proxies.
Show less - Date Issued
- 2015
- Identifier
- CFE0005919, ucf:50825
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005919
- Title
- Analysis of Commutativity with state-chart graph representation of concurrent programs.
- Creator
-
Debnath, Kishore, Dechev, Damian, Leavens, Gary, Bassiouni, Mostafa, University of Central Florida
- Abstract / Description
-
We present a new approach to check for Commutativity in concurrent programs from their run-time state-chart graphs. Two operations are said to be commutative if changing the order of their execution do not change the resultant effect on the working object. Commutative property is capable of boosting performance in concurrent transactions such that transactional concurrency is comparable to a non-blocking linearizable version of a similar data structure type. Transactional concurrency is a...
Show moreWe present a new approach to check for Commutativity in concurrent programs from their run-time state-chart graphs. Two operations are said to be commutative if changing the order of their execution do not change the resultant effect on the working object. Commutative property is capable of boosting performance in concurrent transactions such that transactional concurrency is comparable to a non-blocking linearizable version of a similar data structure type. Transactional concurrency is a technique that analyses object semantics, as object states, to determine conflicts and recovery between conflicting operations. Processes that commute at object level can be executed concurrently at transaction level without conflicting with one another. In our approach we generate graphs by tracking run-time execution of concurrent program and representing object states in all possible thread interleavings as states and transitions. Using state-chart notations, we capture the object states at each execution step and compare their states before and after transitions as processed by a known set of operations reordered in different ways. Considering the non-deterministic nature of concurrent programs, we exhaustively capture program states during method invocation, method response, atomic instruction execution, etc., for determining commutativity. This helps user to examine state transitions at a thread level granularity, across all possible interleavings. With this methodology user can not only verify commutativity, but also can visually check ways in which functions commute at object level, which is an edge over current state-of-the art tools. The object level commutative information helps in identifying faulty implementations and performance improving considerations. We use a graph database to represent state nodes that further assists to check for other concurrency properties using cypher queries.
Show less - Date Issued
- 2016
- Identifier
- CFE0006290, ucf:51608
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006290
- Title
- A Comparison of Concurrent Correctness Criteria for Shared Memory Based Data Structure.
- Creator
-
Bhattacharya, Dipanjan, Dechev, Damian, Leavens, Gary, Bassiouni, Mostafa, University of Central Florida
- Abstract / Description
-
Developing concurrent algorithms requires safety and liveness to be defined in order to understand their proper behavior. Safety refers to the correctness criteria while liveness is the progress guarantee. Nowadays there are a variety of correctness conditions for concurrent objects. The way these correctness conditions differ and the various trade-offs they present with respect to performance, usability, and progress guarantees is poorly understood. This presents a daunting task for the...
Show moreDeveloping concurrent algorithms requires safety and liveness to be defined in order to understand their proper behavior. Safety refers to the correctness criteria while liveness is the progress guarantee. Nowadays there are a variety of correctness conditions for concurrent objects. The way these correctness conditions differ and the various trade-offs they present with respect to performance, usability, and progress guarantees is poorly understood. This presents a daunting task for the developers and users of such concurrent algorithms who are trying to better understand the correctness of their code and the various trade-offs associated with their design choices and use. The purpose of this study is to explore the set of known correctness conditions for concurrent objects, find their correlations and categorize them, and provide insights regarding their implications with respect to performance and usability. In this thesis, a comparative study of Linearizability, Sequential Consistency, Quiescent Consistency and Quasi Linearizability will be presented using data structures like FIFO Queues, Stacks, and Priority Queues, and with a case study for performance of these implementations using different correctness criteria.
Show less - Date Issued
- 2016
- Identifier
- CFE0006263, ucf:51046
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006263
- Title
- Opportunistic Networks in Campus Environments.
- Creator
-
Bacanli, Salih Safa, Turgut, Damla, Guha, Ratan, Bassiouni, Mostafa, University of Central Florida
- Abstract / Description
-
Opportunistic communication is an active research area in wireless sensor networks. Exploiting the opportunities to communicate between devices in an unstable network is one of the main challenges of the opportunistic communication. In this thesis, we propose an infrastructure-independent opportunistic mobile social networking strategy for efficient message broadcasting in campus environments. Specifically, we focus on the application scenario of university campuses. In our model, the...
Show moreOpportunistic communication is an active research area in wireless sensor networks. Exploiting the opportunities to communicate between devices in an unstable network is one of the main challenges of the opportunistic communication. In this thesis, we propose an infrastructure-independent opportunistic mobile social networking strategy for efficient message broadcasting in campus environments. Specifically, we focus on the application scenario of university campuses. In our model, the students' smartphones forward messages to each other. The messages are created spontaneously as independent events in various places of the campus. The events can be either urgent security alerts or private announcements to the students who are currently on the campus. Our proposed state-based campus routing (SCR) protocol is based on the idle and active states of the students in indoor and outdoor environments. The proposed model is analyzed through extensive network simulations using mobility datasets collected from students on University of Milano, University of Cambridge and University of St Andrews campuses. The opportunistic network model and the SCR protocol is compared with epidemic, epidemic with TTS (Times-To-Send), PROPHET(Probabilistic Routing on History of Encounters), NDAO (Nodes Density Aware Opportunistic) and random routing protocols. We observe that the message delivery performance of SCR is close to Epidemic, PROPHET and NDAO while SCR reduces the amount of message transmissions.
Show less - Date Issued
- 2015
- Identifier
- CFE0006258, ucf:51038
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006258
- Title
- Placement of Mode and Wavelength Converters for Throughput Enhancement in Optical Networks.
- Creator
-
Abdulrahman, Ruaa, Bassiouni, Mostafa, Chatterjee, Mainak, Zou, Changchun, University of Central Florida
- Abstract / Description
-
The success of recent experiments to transport data using combined wavelength division multiplexed (WDM) and mode-division multiplexed (MDM) transmission has generated optimism for the attainment of optical networks with unprecedented bandwidth capacity, exceeding the fundamental Shannon capacity limit attained by WDM alone. Optical mode converters and wavelength converters are devices that can be placed in future optical nodes (routers) to prevent or reduce the connection blocking rate and...
Show moreThe success of recent experiments to transport data using combined wavelength division multiplexed (WDM) and mode-division multiplexed (MDM) transmission has generated optimism for the attainment of optical networks with unprecedented bandwidth capacity, exceeding the fundamental Shannon capacity limit attained by WDM alone. Optical mode converters and wavelength converters are devices that can be placed in future optical nodes (routers) to prevent or reduce the connection blocking rate and consequently increase network throughput. In this thesis, the specific problem of the placement of mode converters (MC) and mode-wavelength converters (MWC) in combined mode and wavelength division multiplexing (MWDM) networks is investigated. Four previously proposed wavelength converter placement heuristics are extended to handle the placement of MC and MWC in MWDM networks. A simple but effective method for the placement of mode and wavelength converters in MWDM networks is proposed based on ranking the nodes with respect to the volume of received connection requests. The results of extensive simulation tests to evaluate the new method and compare its performance with the performance of the other four heuristics are presented. The thesis provides extensive comparison results among the five converter placement methods using different network topologies and under different network loads. The results demonstrate the effectiveness of the new proposed method in achieving lower blocking rates compared to the other more-complex converter placement heuristics.
Show less - Date Issued
- 2014
- Identifier
- CFE0005118, ucf:50756
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005118
- Title
- Improving fairness, throughput and blocking performance for long haul and short reach optical networks.
- Creator
-
Tariq, Sana, Bassiouni, Mostafa, Zou, Changchun, Turgut, Damla, Li, Guifang, University of Central Florida
- Abstract / Description
-
Innovations in optical communication are expected to transform the landscape of global communications, internet and datacenter networks. This dissertation investigates several important issues in optical communication such as fairness, throughput, blocking probability and differentiated quality of service (QoS). Novel algorithms and new approaches have been presented to improve the performance of optical circuit switching (OCS) and optical burst switching (OBS) for long haul, and datacenter...
Show moreInnovations in optical communication are expected to transform the landscape of global communications, internet and datacenter networks. This dissertation investigates several important issues in optical communication such as fairness, throughput, blocking probability and differentiated quality of service (QoS). Novel algorithms and new approaches have been presented to improve the performance of optical circuit switching (OCS) and optical burst switching (OBS) for long haul, and datacenter networks. Extensive simulations tests have been conducted to evaluate the effectiveness of the proposed algorithms. These simulation tests were performed over a number of network topologies such as ring, mesh and U.S. Long-Haul, some high processing computing (HPC) topologies such as 2D and 6D mesh torus topologies and modern datacenter topologies such as FatTree and BCube.Two new schemes are proposed for long haul networks to improve throughput and hop count fairness in OBS networks. The idea is motivated by the observation that providing a slightly more priority to longer bursts over short bursts can significantly improve the throughput of the OBS networks without adversely affecting hop-count fairness. The results of extensive performance tests have shown that proposed schemes improve the throughput of optical OBS networks and enhance the hop-count fairness. Another contribution of this dissertation is the research work on developing routing and wavelength assignment schemes in multimode fiber networks. Two additional schemes for long haul networks are presented and evaluated over multimode fiber networks. First for alleviating the fairness problem in OBS networks using wavelength-division multiplexing as well as mode-division multiplexing while the second scheme for achieving higher throughput without sacrificing hop count fairness.We have also shown the significant benefits of using both mode division multiplexing and wavelength division multiplexing in real-life short-distance optical networks such as the optical circuit switching networks used in the hybrid electronic-optical switching architectures for datacenters. We evaluated four mode and wavelength assignment heuristics and compared their throughput performance. We also included preliminary results of impact of the cascaded mode conversion constraint on network throughput. Datacenter and high performance computing networks share a number of common performance goals. Another highly efficient adaptive mode wavelength- routing algorithm is presented over OBS networks to improve throughput of these networks. The effectiveness of the proposed model has been validated by extensive simulation results.In order to optimize bandwidth and maximize throughput of datacenters, an extension of TCP called multipath-TCP (MPTCP) has been evaluated over an OBS network using dense interconnect datacenter topologies. We have proposed a service differentiation scheme using MPTCP over OBS for datacenter traffic. The scheme is evaluated over mixed workload traffic model of datacenters and is shown to provide tangible service differentiation between flows of different priority levels. An adaptive QoS differentiation architecture is proposed for software defined optical datacenter networks using MPTCP over OBS. This scheme prioritizes flows based on current network state.
Show less - Date Issued
- 2015
- Identifier
- CFE0005721, ucf:50146
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005721
- Title
- Improving the performance of data-intensive computing on Cloud platforms.
- Creator
-
Dai, Wei, Bassiouni, Mostafa, Zou, Changchun, Wang, Jun, Lin, Mingjie, Bai, Yuanli, University of Central Florida
- Abstract / Description
-
Big Data such as Terabyte and Petabyte datasets are rapidly becoming the new norm for various organizations across a wide range of industries. The widespread data-intensive computing needs have inspired innovations in parallel and distributed computing, which has been the effective way to tackle massive computing workload for decades. One significant example is MapReduce, which is a programming model for expressing distributed computations on huge datasets, and an execution framework for data...
Show moreBig Data such as Terabyte and Petabyte datasets are rapidly becoming the new norm for various organizations across a wide range of industries. The widespread data-intensive computing needs have inspired innovations in parallel and distributed computing, which has been the effective way to tackle massive computing workload for decades. One significant example is MapReduce, which is a programming model for expressing distributed computations on huge datasets, and an execution framework for data-intensive computing on commodity clusters as well. Since it was originally proposed by Google, MapReduce has become the most popular technology for data-intensive computing. While Google owns its proprietary implementation of MapReduce, an open source implementation called Hadoop has gained wide adoption in the rest of the world. The combination of Hadoop and Cloud platforms has made data-intensive computing much more accessible and affordable than ever before.This dissertation addresses the performance issue of data-intensive computing on Cloud platforms from three different aspects: task assignment, replica placement, and straggler identification. Both task assignment and replica placement are subjects closely related to load balancing, which is one of the key issues that can significantly affect the performance of parallel and distributed applications. While task assignment schemes strive to balance data processing load among cluster nodes to achieve minimum job completion time, replica placement policies aim to assign block replicas to cluster nodes according to their processing capabilities to exploit data locality to the maximum extent. Straggler identification is also one of the crucial issues data-intensive computing has to deal with, as the overall performance of parallel and distributed applications is often determined by the node with the lowest performance. The results of extensive evaluation tests confirm that the schemes/policies proposed in this dissertation can improve the performance of data-intensive applications running on Cloud platforms.
Show less - Date Issued
- 2017
- Identifier
- CFE0006731, ucf:51896
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006731
- Title
- Value-of-Information based Data Collection in Underwater Sensor Networks.
- Creator
-
Khan, Fahad, Turgut, Damla, Yuksel, Murat, Behal, Aman, Bassiouni, Mostafa, Garibay, Ivan, University of Central Florida
- Abstract / Description
-
Underwater sensor networks are deployed in marine environments, presenting specific challenges compared to sensor networks deployed in terrestrial settings. Among the major issues that underwater sensor networks face is communication medium limitations that result in low bandwidth and long latency. This creates problems when these networks need to transmit large amounts of data over long distances. A possible solution to address this issue is to use mobile sinks such as autonomous underwater...
Show moreUnderwater sensor networks are deployed in marine environments, presenting specific challenges compared to sensor networks deployed in terrestrial settings. Among the major issues that underwater sensor networks face is communication medium limitations that result in low bandwidth and long latency. This creates problems when these networks need to transmit large amounts of data over long distances. A possible solution to address this issue is to use mobile sinks such as autonomous underwater vehicles (AUVs) to offload these large quantities of data. Such mobile sinks are called data mules. Often it is the case that a sensor network is deployed to report events that require immediate attention. Delays in reporting such events can have catastrophic consequences. In this dissertation, we present path planning algorithms that help in prioritizing data retrieval from sensor nodes in such a manner that nodes that require more immediate attention would be dealt with at the earliest. In other words, the goal is to improve the Quality of Information (QoI) retrieved. The path planning algorithms proposed in this dissertation are based on heuristics meant to improve the Value of Information (VoI) retrieved from a system. Value of information is a construct that helps in encoding the valuation of an information segment i.e. it is the price an optimal player would pay to obtain a segment of information in a game theoretic setting. Quality of information and value of information are complementary concepts. In this thesis, we formulate a value of information model for sensor networks and then consider the constraints that arise in underwater settings. On the basis of this, we develop a VoI-based path planning problem statement and propose heuristics that solve the path planning problem. We show through simulation studies that the proposed strategies improve the value, and hence, quality of the information retrieved. It is important to note that these path planning strategies can be applied equally well in terrestrial settings that deploy mobile sinks for data collection.
Show less - Date Issued
- 2019
- Identifier
- CFE0007476, ucf:52683
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007476
- Title
- A(&)nbsp;Framework For Modeling Attacker Capabilities with Deception.
- Creator
-
Hassan, Sharif, Guha, Ratan, Bassiouni, Mostafa, Chatterjee, Mainak, DeMara, Ronald, University of Central Florida
- Abstract / Description
-
In this research we built a custom experimental range using opensource emulated and custom pure honeypots designed to detect or capture attacker activity. The focus is to test the effectiveness of a deception in its ability to evade detection coupled with attacker skill levels. The range consists of three zones accessible via virtual private networking. The first zone houses varying configurations of opensource emulated honeypots, custom built pure honeypots, and real SSH servers. The second...
Show moreIn this research we built a custom experimental range using opensource emulated and custom pure honeypots designed to detect or capture attacker activity. The focus is to test the effectiveness of a deception in its ability to evade detection coupled with attacker skill levels. The range consists of three zones accessible via virtual private networking. The first zone houses varying configurations of opensource emulated honeypots, custom built pure honeypots, and real SSH servers. The second zone acts as a point of presence for attackers. The third zone is for administration and monitoring. Using the range, both a control and participant-based experiment were conducted. We conducted control experiments to baseline and empirically explore honeypot detectability amongst other systems through adversarial testing. We executed a series of tests such as network service sweep, enumeration scanning, and finally manual execution. We also selected participants to serve as cyber attackers against the experiment range of varying skills having unique tactics, techniques and procedures in attempting to detect the honeypots. We have concluded the experiments and performed data analysis. We measure the anticipated threat by presenting the Attacker Bias Perception Profile model. Using this model, each participant is ranked based on their overall threat classification and impact. This model is applied to the results of the participants which helps align the threat to likelihood and impact of a honeypot being detected. The results indicate the pure honeypots are significantly difficult to detect. Emulated honeypots are grouped in different categories based on the detection and skills of the attackers. We developed a framework abstracting the deceptive process, the interaction with system elements, the use of intelligence, and the relationship with attackers. The framework is illustrated by our experiment case studies and the attacker actions, the effects on the system, and impact to the success.
Show less - Date Issued
- 2019
- Identifier
- CFE0007467, ucf:52659
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007467
- Title
- Masquerading Techniques in IEEE 802.11 Wireless Local Area Networks.
- Creator
-
Nakhila, Omar, Zou, Changchun, Turgut, Damla, Bassiouni, Mostafa, Chatterjee, Mainak, Wang, Chung-Ching, University of Central Florida
- Abstract / Description
-
The airborne nature of wireless transmission offers a potential target for attackers to compromise IEEE 802.11 Wireless Local Area Network (WLAN). In this dissertation, we explore the current WLAN security threats and their corresponding defense solutions. In our study, we divide WLAN vulnerabilities into two aspects, client, and administrator. The client-side vulnerability investigation is based on examining the Evil Twin Attack (ETA) while our administrator side research targets Wi-Fi...
Show moreThe airborne nature of wireless transmission offers a potential target for attackers to compromise IEEE 802.11 Wireless Local Area Network (WLAN). In this dissertation, we explore the current WLAN security threats and their corresponding defense solutions. In our study, we divide WLAN vulnerabilities into two aspects, client, and administrator. The client-side vulnerability investigation is based on examining the Evil Twin Attack (ETA) while our administrator side research targets Wi-Fi Protected Access II (WPA2). Three novel techniques have been presented to detect ETA. The detection methods are based on (1) creating a secure connection to a remote server to detect the change of gateway's public IP address by switching from one Access Point (AP) to another. (2) Monitoring multiple Wi-Fi channels in a random order looking for specific data packets sent by the remote server. (3) Merging the previous solutions into one universal ETA detection method using Virtual Wireless Clients (VWCs). On the other hand, we present a new vulnerability that allows an attacker to force the victim's smartphone to consume data through the cellular network by starting the data download on the victim's cell phone without the victim's permission. A new scheme has been developed to speed up the active dictionary attack intensity on WPA2 based on two novel ideas. First, the scheme connects multiple VWCs to the AP at the same time-each VWC has its own spoofed MAC address. Second, each of the VWCs could try many passphrases using single wireless session. Furthermore, we present a new technique to avoid bandwidth limitation imposed by Wi-Fi hotspots. The proposed method creates multiple VWCs to access the WLAN. The combination of the individual bandwidth of each VWC results in an increase of the total bandwidth gained by the attacker. All proposal techniques have been implemented and evaluated in real-life scenarios.
Show less - Date Issued
- 2018
- Identifier
- CFE0007063, ucf:51979
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007063
- Title
- D-FENS: DNS Filtering (&) Extraction Network System for Malicious Domain Names.
- Creator
-
Spaulding, Jeffrey, Mohaisen, Aziz, Leavens, Gary, Bassiouni, Mostafa, Fu, Xinwen, Posey, Clay, University of Central Florida
- Abstract / Description
-
While the DNS (Domain Name System) has become a cornerstone for the operation of the Internet, it has also fostered creative cases of maliciousness, including phishing, typosquatting, and botnet communication among others. To address this problem, this dissertation focuses on identifying and mitigating such malicious domain names through prior knowledge and machine learning. In the first part of this dissertation, we explore a method of registering domain names with deliberate typographical...
Show moreWhile the DNS (Domain Name System) has become a cornerstone for the operation of the Internet, it has also fostered creative cases of maliciousness, including phishing, typosquatting, and botnet communication among others. To address this problem, this dissertation focuses on identifying and mitigating such malicious domain names through prior knowledge and machine learning. In the first part of this dissertation, we explore a method of registering domain names with deliberate typographical mistakes (i.e., typosquatting) to masquerade as popular and well-established domain names. To understand the effectiveness of typosquatting, we conducted a user study which helped shed light on which techniques were more (")successful(") than others in deceiving users. While certain techniques fared better than others, they failed to take the context of the user into account. Therefore, in the second part of this dissertation we look at the possibility of an advanced attack which takes context into account when generating domain names. The main idea is determining the possibility for an adversary to improve their (")success(") rate of deceiving users with specifically-targeted malicious domain names. While these malicious domains typically target users, other types of domain names are generated by botnets for command (&) control (C2) communication. Therefore, in the third part of this dissertation we investigate domain generation algorithms (DGA) used by botnets and propose a method to identify DGA-based domain names. By analyzing DNS traffic for certain patterns of NXDomain (non-existent domain) query responses, we can accurately predict DGA-based domain names before they are registered. Given all of these approaches to malicious domain names, we ultimately propose a system called D-FENS (DNS Filtering (&) Extraction Network System). D-FENS uses machine learning and prior knowledge to accurately predict unreported malicious domain names in real-time, thereby preventing Internet devices from unknowingly connecting to a potentially malicious domain name.
Show less - Date Issued
- 2018
- Identifier
- CFE0007587, ucf:52540
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007587
