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(1 - 20 of 39)
Pages
- Title
- A PERFORMANCE COMPARISON OF CLUSTERING ALGORITHMS IN AD HOCNETWORKS.
- Creator
-
Yeung, Chun, Turgut, Damla, University of Central Florida
- Abstract / Description
-
An ad hoc network is comprised of wireless mobile nodes without the need of wired network infrastructure. Due to the limited transmission range of nodes, the exchange of data between them may not be possible using direct communication. Partitioning the network into clusters and electing a clusterhead for each cluster to assist with the resource allocation and data packet transmissions among its members and neighboring clusterheads is one of the most common ways of providing support for the...
Show moreAn ad hoc network is comprised of wireless mobile nodes without the need of wired network infrastructure. Due to the limited transmission range of nodes, the exchange of data between them may not be possible using direct communication. Partitioning the network into clusters and electing a clusterhead for each cluster to assist with the resource allocation and data packet transmissions among its members and neighboring clusterheads is one of the most common ways of providing support for the existing ad hoc routing protocols. This thesis presents the performance comparison of four ad hoc network clustering protocols: Dynamic Mobile Adaptive Clustering (DMAC), Highest-Degree and Lowest-ID algorithms, and Weighted Clustering Algorithm (WCA). Yet Another Extensible Simulation (YAES) was used as the simulator to carry out the simulations.
Show less - Date Issued
- 2006
- Identifier
- CFE0001314, ucf:47022
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001314
- Title
- Multiple-Case Study and Exploratory Analysis of the Implementation of Value-Added Teacher Performance Assessment on Eighth Grade Student Achievement in Ohio, Pennsylvania, and Tennessee.
- Creator
-
Carter, James, Taylor, Rosemarye, Doherty, Walter, Hahs-Vaughn, Debbie, Gordon, William, University of Central Florida
- Abstract / Description
-
The goal of this research was to analyze the academic impact of the implementation of the Value Added Assessment Model. The researcher analyzed the Value Added Assessment Models in the three Value Added Assessment Model states that had implemented the Value Added Assessment Model for more than five years. Additionally, the research was done by analyzing the academic impact as measured by the eighth grade reading NAEP and the eighth grade mathematics NAEP. The researcher paired the three...
Show moreThe goal of this research was to analyze the academic impact of the implementation of the Value Added Assessment Model. The researcher analyzed the Value Added Assessment Models in the three Value Added Assessment Model states that had implemented the Value Added Assessment Model for more than five years. Additionally, the research was done by analyzing the academic impact as measured by the eighth grade reading NAEP and the eighth grade mathematics NAEP. The researcher paired the three states that had implemented Value Added Assessment Model for more than five years, with three demographically matched states that had not implemented Value Added Assessment Model. The states were matched as follows: Ohio (Value Added Assessment Model implementing state) with Michigan (non Value Added Assessment Model state), Pennsylvania (Value Added Assessment Model implementing state) with Virginia (non Value Added Assessment Model state) and Tennessee (Value Added Assessment Model implementing state) with Georgia (non Value Added Assessment Model state). The mean composite scale score in NAEP from the following categories of students were compared and analyzed: 1) All students 2) White students 3) Black students 4) National School Lunch Program Eligible Students 5) National School Lunch Program Ineligible Students 6) Exceptional Education students. The results of the study indicated that the impact of Value Added Assessment Model on academic impact as measured by the eighth grade reading NAEP and the eighth grade mathematics NAEP was negligible.
Show less - Date Issued
- 2014
- Identifier
- CFE0005468, ucf:52862
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005468
- Title
- IS ECONOMIC VALUE ADDED (EVA) THE BEST WAY TO ASSEMBLE A PORTFOLIO?.
- Creator
-
Pataky, Tamas, Gilkeson, James, University of Central Florida
- Abstract / Description
-
In search of a better investment metric, researchers began to study Economic Value Added, or EVA, which was introduced in 1991 by Stern Stewart & Co in their book, "The Quest for Value" (Turvey, 2000). Stern Stewart & Co devised EVA as a better alternative to evaluate investment projects within the corporate finance field, later to be considered for use as a performance metric for investor use. A wide array of multinational corporations, such as Coca-Cola, Briggs and Stratton, and AT&T...
Show moreIn search of a better investment metric, researchers began to study Economic Value Added, or EVA, which was introduced in 1991 by Stern Stewart & Co in their book, "The Quest for Value" (Turvey, 2000). Stern Stewart & Co devised EVA as a better alternative to evaluate investment projects within the corporate finance field, later to be considered for use as a performance metric for investor use. A wide array of multinational corporations, such as Coca-Cola, Briggs and Stratton, and AT&T adopted the EVA method, which led to EVA's worldwide acclaim. Several points in the study reveal that EVA does not offer less risk, higher returns, and more adaptability for an investor. In fact, EVA underperformed the traditional portfolio performance metrics in key measurements including mean returns, and confidence intervals. EVA is a difficult performance metric to calculate, with several complex components that can be calculated in several different ways such as NOPAT, cost of equity, and cost of debt. Any information that is inaccurate or lacking can significantly impact the outcomes. Traditional performance metrics, on the other hand, such as ROA, ROE, and E/P are simple to calculate with few components, and only one way to calculate them.
Show less - Date Issued
- 2012
- Identifier
- CFH0004289, ucf:44909
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004289
- Title
- MITIGATING MISBEHAVIOR IN WIRELESS NETWORKS: A GAME THEORETIC APPROACH.
- Creator
-
Wang, Wenjing, Chatterjee, Mainak, University of Central Florida
- Abstract / Description
-
In a distributed wireless system, multiple network nodes behave cooperatively towards a common goal. Though such assumptions on cooperation are desirable (e.g., controlling the transmit power level, reducing interference for each other, revealing private information, adhering to network policies) for analyzing and modeling, certain nodes belonging to a real-world system have often shown to deviate. These nodes, known as misbehaving nodes, bring more challenges to the design of the wireless...
Show moreIn a distributed wireless system, multiple network nodes behave cooperatively towards a common goal. Though such assumptions on cooperation are desirable (e.g., controlling the transmit power level, reducing interference for each other, revealing private information, adhering to network policies) for analyzing and modeling, certain nodes belonging to a real-world system have often shown to deviate. These nodes, known as misbehaving nodes, bring more challenges to the design of the wireless network because the unreliable channel makes the actions of the nodes hidden from each other. In this dissertation, we analyze two types of misbehavior, namely, selfish noncooperation and malicious attacking. We apply game theoretic techniques to model the interactions among the nodes in the network. First, we consider a homogeneous unreliable channel and analyze the necessary and sufficient conditions to enforce cooperative packet forwarding among a node pair. We formulate an anti-collusion game and derive the conditions that achieve full cooperation when the non-cooperative nodes collude. In addition, we consider multi-hop communication with a heterogeneous channel model. We refine our game model as a hidden action game with imperfect private monitoring. A state machine based strategy is proposed to reach Nash Equilibrium. The strategy attains cooperative packet forwarding with heterogeneous channel and requires only partial and imperfect information. Furthermore, it also enforces cooperation in multi-hop packet forwarding. To tackle the malicious attacks, we use Bayesian game analysis to show the existence of equilibrium in the detection game and argue that it might not be profitable to isolate the malicious nodes upon detection. We propose the concept of "coexistence with malicious nodes" by proving the co-existence equilibrium and derive the conditions that achieve the equilibrium. This research is further accomplished by extensive simulation studies. Simulation results illustrate the properties of the games and the derived equilibria. The results validate our design philosophy and clearly indicate that the proposed game theoretic solutions can be effectively used to enforce cooperation and mitigate attacks.
Show less - Date Issued
- 2010
- Identifier
- CFE0003080, ucf:48294
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003080
- Title
- An analysis of the difference between assessed instructional practices, value-added measures, and learning gains of secondary reading teachers.
- Creator
-
Fritz, Ronald, Taylor, Rosemarye, Baldwin, Lee, Doherty, Walter, Kennedy, Mary, University of Central Florida
- Abstract / Description
-
The purpose of this study was to analyze the relationship that exists among instructional practice scores, value-added measures, and learning gains for the Large Urban School District (LUSD) among reading teachers in Grades 6-12 for the 2012-2013 school year. In addition, this study was also conducted to address the perceptions of secondary school principals and assistant principals regarding the relationship of the three variables and their relevance in making personnel decisions....
Show moreThe purpose of this study was to analyze the relationship that exists among instructional practice scores, value-added measures, and learning gains for the Large Urban School District (LUSD) among reading teachers in Grades 6-12 for the 2012-2013 school year. In addition, this study was also conducted to address the perceptions of secondary school principals and assistant principals regarding the relationship of the three variables and their relevance in making personnel decisions. Quantitative data were obtained from school district databases for observation scores, value-added measures, and standardized assessment achievement data to determine the relationship among the variables. In addition, a perception survey was completed by secondary school principals and assistant principals. With a sample size of 138, the survey yielded a return rate of 84%. The data were analyzed to determine actual relationships among instructional practice scores, value-added measures, and learning gains, as well as how the participants perceived each variable in isolation. The literature review supported the findings regarding the inflation of observation scores by school administrators. The only significant relationship (.48) existed between value-added measures and learning gains. Likewise, school leaders in the LUSD believed that their observations were important in analyzing the needs of their teachers and should be included in summative evaluations. Learning gains were supported by the participants more than instructional practice scores and value-added measures as evidence of effective instruction. The literature review revealed past program evaluation studies regarding the Florida Comprehensive Achievement Test (FCAT) as a valid measure for assessing grade level benchmarks. The information in this study is valuable and suggests that continued professional learning for school leaders regarding classroom observations to improve inter-rater reliability is needed. Likewise, school leaders would benefit from understanding the relationships that exist among instructional practice scores, value-added measures, and learning gains to drive conversations with teachers regarding rigorous instruction.
Show less - Date Issued
- 2014
- Identifier
- CFE0005494, ucf:50362
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005494
- Title
- VOICE ONSET TIME PRODUCTION IN INDIVIDUALS WTH ALZHEIMER'S DISEASE.
- Creator
-
Baker, Julie Baker, Ryalls, Jack, University of Central Florida
- Abstract / Description
-
In the present study, voice onset time (VOT) measurements were compared between a group of individuals with moderate Alzheimer's disease (AD) and a group of healthy age- and gender-matched peers. Participants read a list of consonant-vowel-consonant (CVC) words, which included the six stop consonants. Recordings were gathered and digitized. The VOT measurements were made from oscillographic displays obtained from the Brown Laboratory Interactive Speech System (BLISS) implemented on an IBM...
Show moreIn the present study, voice onset time (VOT) measurements were compared between a group of individuals with moderate Alzheimer's disease (AD) and a group of healthy age- and gender-matched peers. Participants read a list of consonant-vowel-consonant (CVC) words, which included the six stop consonants. Recordings were gathered and digitized. The VOT measurements were made from oscillographic displays obtained from the Brown Laboratory Interactive Speech System (BLISS) implemented on an IBM-compatible computer. VOT measures for the participants' six stop consonant productions were subjected to statistical analysis. The results of the study indicated that differences in VOT values were not statistically significant in the speakers with Alzheimer's disease from the normal control speakers.
Show less - Date Issued
- 2006
- Identifier
- CFE0001269, ucf:46918
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001269
- Title
- COLLABORATION ENFORCEMENT IN MOBILE AD HOC NETWORKS.
- Creator
-
Jiang, Ning, Hua, Kien, University of Central Florida
- Abstract / Description
-
Mobile Ad hoc NETworks (MANETs) have attracted great research interest in recent years. Among many issues, lack of motivation for participating nodes to collaborate forms a major obstacle to the adoption of MANETs. Many contemporary collaboration enforcement techniques employ reputation mechanisms for nodes to avoid and penalize malicious participants. Reputation information is propagated among participants and updated based on complicated trust relationships to thwart false accusation of...
Show moreMobile Ad hoc NETworks (MANETs) have attracted great research interest in recent years. Among many issues, lack of motivation for participating nodes to collaborate forms a major obstacle to the adoption of MANETs. Many contemporary collaboration enforcement techniques employ reputation mechanisms for nodes to avoid and penalize malicious participants. Reputation information is propagated among participants and updated based on complicated trust relationships to thwart false accusation of benign nodes. The aforementioned strategy suffers from low scalability and is likely to be exploited by adversaries. To address these problems, we first propose a finite state model. With this technique, no reputation information is propagated in the network and malicious nodes cannot cause false penalty to benign hosts. Misbehaving node detection is performed on-demand; and malicious node punishment and avoidance are accomplished by only maintaining reputation information within neighboring nodes. This scheme, however, requires that each node equip with a tamper-proof hardware. In the second technique, no such restriction applies. Participating nodes classify their one-hop neighbors through direct observation and misbehaving nodes are penalized within their localities. Data packets are dynamically rerouted to circumvent selfish nodes. In both schemes, overall network performance is greatly enhanced. Our approach significantly simplifies the collaboration enforcement process, incurs low overhead, and is robust against various malicious behaviors. Simulation results based on different system configurations indicate that the proposed technique can significantly improve network performance with very low communication cost.
Show less - Date Issued
- 2006
- Identifier
- CFE0001047, ucf:46820
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001047
- 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
- A Framework for Measuring the Value-Added of Knowledge Processes with Analysis of Process Interactions and Dynamics.
- Creator
-
Cintron, Jose, Rabelo, Luis, Elshennawy, Ahmad, Thompson, William, Ajayi, Richard, University of Central Florida
- Abstract / Description
-
The most known and widely used methods use cash flows and tangible assets to measure the impact of investments in the organization's outputs. But in the last decade many newer organizations whose outputs are heavily dependent on information technology utilize knowledge as their main asset. These organizations' market values lie on the knowledge of its employees and their technological capabilities. In the current technology-based business landscape the value added by assets utilized for...
Show moreThe most known and widely used methods use cash flows and tangible assets to measure the impact of investments in the organization's outputs. But in the last decade many newer organizations whose outputs are heavily dependent on information technology utilize knowledge as their main asset. These organizations' market values lie on the knowledge of its employees and their technological capabilities. In the current technology-based business landscape the value added by assets utilized for generation of outputs cannot be appropriately measured and managed without considering the role that intangible assets and knowledge play in executing processes. The analysis of processes for comparison and decision making based on intangible value added can be accomplished using the knowledge required to execute processes. The measurement of value added by knowledge can provide a more realistic framework for analysis of processes where traditional cost methods are not appropriate, enabling managers to better allocate and control knowledge-based processes. Further consideration of interactions and complexity between proposed process alternatives can yield answers about where and when investments can improve value-added while dynamically providing higher returns on investment.
Show less - Date Issued
- 2013
- Identifier
- CFE0004983, ucf:49585
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004983
- Title
- A Priori Analysis of Error and Bias in Value-Added Models.
- Creator
-
Lavery, Matthew, Hahs-Vaughn, Debbie, Sivo, Stephen, Bai, Haiyan, Amrein-Beardsley, Audrey, University of Central Florida
- Abstract / Description
-
Over the past 20 years, value-added models (VAMs) have become increasingly popular in educational assessment and accountability policies because of the sophisticated statistical controls these models use to purportedly isolate the effect of a single teacher on the learning gains of his or her students. The present research uses a Monte Carlo simulation study design in order to investigate whether VAMs are able to provide accurate estimates of teacher effectiveness when all assumptions are met...
Show moreOver the past 20 years, value-added models (VAMs) have become increasingly popular in educational assessment and accountability policies because of the sophisticated statistical controls these models use to purportedly isolate the effect of a single teacher on the learning gains of his or her students. The present research uses a Monte Carlo simulation study design in order to investigate whether VAMs are able to provide accurate estimates of teacher effectiveness when all assumptions are met and to determine how robust the models are to endogenous peer effects and nonrandom assignment of students to classroom. The researcher generates three years of simulated achievement data for 18,750 students taught by 125 teachers, and analyzes this data with a linear mixed model similar to the SAS(&)#174; EVAAS(&)#174; Multivariate Response Model (MRM; M1), a basic covariate adjustment model (M2), and variations on these models designed to estimate random classroom effects. Findings indicate that the modified EVAAS may be too computationally onerous to be of practical use, and that modified covariate adjustment models do not perform significantly differently than the basic covariate adjustment model. When all assumptions are met, M1 is more accurate than M2, but both models perform reasonably well, misclassifying fewer than 5% of teachers on average. M1 is more robust to endogenous peer effects than M2, however both models misclassified more teachers than when all assumptions are met. M2 is more robust to nonrandom assignment of students than M1. Assigning teachers a balanced schedule of nonrandom classes with low, medium, and high prior achievement seemed to mitigate the problems that nonrandom assignment caused for M1, but made M2 less accurate. Implications for practice and future research are discussed.
Show less - Date Issued
- 2016
- Identifier
- CFE0006344, ucf:51568
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006344
- Title
- A Study of The Marzano Teacher Evaluation Model and Student Achievement at 24 Elementary Schools In A Large Suburban School District In Central Florida.
- Creator
-
Flowers, Amy, Murray, Kenneth, Doherty, Walter, Murray, Barbara, Baldwin, Gordon, University of Central Florida
- Abstract / Description
-
The focus of this research was to examine the initial year of implementation of the Marzano Teacher Evaluation Model and iObservation(&)#174; tool (Learning Sciences International, 2012) as it related to student achievement in the School District of Osceola County, Florida and to determine if the Marzano model improved the ability to determine teacher effectiveness with more accuracy than previous models of teacher evaluation used in the school district. Twelve research questions guided this...
Show moreThe focus of this research was to examine the initial year of implementation of the Marzano Teacher Evaluation Model and iObservation(&)#174; tool (Learning Sciences International, 2012) as it related to student achievement in the School District of Osceola County, Florida and to determine if the Marzano model improved the ability to determine teacher effectiveness with more accuracy than previous models of teacher evaluation used in the school district. Twelve research questions guided this study concerning the relationship and predictability between the variables of teacher instructional practice scores, number of observations reported in the iObservation(&)#174; tool, and student achievement in Grades 3-5 using reading and mathematics FCAT 2.0 DSS scores.Linear Regression analysis suggested that for Grade 3 reading and mathematics the instructional practice mean had statistical significance in predicting performance and was a strong predictor of Grade 3 FCAT reading and mathematics performance. Linear Regression analysis suggested that for Grade 3 reading and mathematics the instructional practice mean had statistical significance in predicting performance and was a strong predictor of Grade 3 FCAT reading and mathematics performance. Linear Regression analysis further suggested no statistical significance or predictability for Grades 4, 5 for instructional practice mean and Grades 3,4,5 for observation mean related to FCAT reading and mathematics performance. Caution should be used when attempting to interpret these findings, as this study was based solely on initial year implementation data. Implications for practice are also discussed in this study.
Show less - Date Issued
- 2013
- Identifier
- CFE0004841, ucf:49711
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004841
- Title
- The fortune teller.
- Creator
-
Brewer, Edward V.
- Date Created
- 1921
- Identifier
- DP0015497_a
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015497_a
- Title
- CONNECTIONLESS APPROACH – A LOCALIZED SCHEME TO MOBILE AD HOC NETWORKS.
- Creator
-
Ho, Yao, Hua, Kien, University of Central Florida
- Abstract / Description
-
According to a Gartner Group (www.gartner.com) report in September 2008, the worldwide telecommunications market is on pace to reach $2 trillion in 2008. Gartner predicts that by 2012, the ratio of mobile to fixed connections will exceed 4-to-1. The North American mobile data market grew to 141.1 million connections in 2007, with a compound annual growth rate of 41.7 percent. It is believed that a large portion will be ad hoc and multi-hop connections, which will open many opportunities for...
Show moreAccording to a Gartner Group (www.gartner.com) report in September 2008, the worldwide telecommunications market is on pace to reach $2 trillion in 2008. Gartner predicts that by 2012, the ratio of mobile to fixed connections will exceed 4-to-1. The North American mobile data market grew to 141.1 million connections in 2007, with a compound annual growth rate of 41.7 percent. It is believed that a large portion will be ad hoc and multi-hop connections, which will open many opportunities for Mobile Ad hoc NETwork (MANET) applications and Wireless Mesh Network (WMN) applications. A MANET is a self-organizing multi-hop wireless network where all nodes participate in the routing and data forwarding process. Such a network can be easily deployed in situations where no base station is available, and a network must be build spontaneously. In applications such as battlefield communications, national crises, disaster recovery, and sensor deployment, a wired network is not available and ad hoc networks provide the only feasible means of communications and information access. Ad hoc networks have also become commonplace for gaming, conferencing, electronic classrooms, and particularly vehicle-to-vehicle communications. A Wireless mash network (WMN) is collection of mesh clients and mesh nodes (routers), with mesh nodes forming the backbone of the network and providing connection to the Internet and other network. Their rapid deployment and ease of maintenance are suitable for on-demand network such as disaster recovery, homeland security, convention centers, hard-to-wire buildings and unfriendly terrains. One important problem with MANET is the routing protocol that needs to work well not just with a small network, but also sustain efficiency and scalability as the network gets expanded and the application transmits data in greater volume. In such an environment, mobility, channel error, and congestion are the main causes for packet loss. Due to mobility of mobile hosts, addressing frequent and unpredictable topology changes is fundamental to MANET research. Two general approaches have been considered: connection-oriented approach and connectionless-oriented approach. In the former, the emphasis is on how to reconnect quickly with low overhead when a broken link occurs. Examples of this approach includes , , , , , , , , , and . In contrast, connectionless-oriented approach focuses on minimizing the occurrence of broken links. We proposed one such scheme called Connectionless Approach (CLA) and . In CLA, the network area is divided into non-overlapping grid cells, each serving as a virtual router. Any physical router (i.e., mobile host), currently inside a virtual router, can help forward the data packet to the next virtual router along the virtual link. This process is repeated until the packet reaches its final destination. Since a virtual link is based on virtual routers which do not move, it is much more robust than physical links used in the connection-oriented techniques. Simulation results in our previous works and , based on GloMoSim , indicate that CLA performs significantly better than connection-oriented techniques (i.e., AODV, DSR, LAR, GRID, TMNR, and GPSR). The contribution of this work consists of investigating and developing new Connectionless-Oriented Approach for Mobile Ad Hoc Network. Two of the greatest impacts of this research are as follows. First, the new approach is targeted towards robustly support high mobility and large scale environment which has been adapted for vehicle-to-vehicle environment in . Second, the detailed simulations which compare eight representative routing protocols, namely AODV, DSR, LAR, GRID, TMNR, GPSR, CBF, and CLA, under high-mobility environments. As many important emergent applications of the technology involved high-mobility nodes, very little is known about the existing routing methods perform relative to each other in high-mobility environments. The simulation results provide insight into ad hoc routing protocols and offer guidelines for mobile ad hoc network applications. Next, we enhanced and extend the connectionless-oriented approach. The current connectionless-oriented approach, however, may suffer from packet drops since traffic congestion is not considered in the packet forwarding policy. We address this weakness by considering the connectionless-oriented approach with a collision avoidance routing technique. After that, we investigate techniques to enforce collaboration among mobile devices in supporting the virtual router functionality. Many works have been published to combat such problem - misbehaving nodes are detected and a routing algorithm is employed to avoid and penalize misbehaving nodes. These techniques, however, cannot be applied to the connectionless-oriented approach since any node in the general direction towards the destination node can potentially help forward the data packets. To address the security and cooperation issues for connectionless-oriented approach, we introduce a cooperation enforcement technique called 3CE (3-Counter Enforcement). In addition, wireless mesh networks have become increasingly popular in recent years. Wireless mash network (WMNs) are collection of mesh clients and mesh nodes (routers), with mesh nodes forming the backbone of the network and providing connection to the Internet and other network. We propose a paradigm that combines virtual routers and mesh nodes to create a hybrid network call VR-Mesh Network. This hybrid network can reduce number of mesh node needed without decrease the performance of the network.
Show less - Date Issued
- 2009
- Identifier
- CFE0002742, ucf:48146
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002742
- Title
- MAMMY.
- Date Created
- 1930s
- Identifier
- DP0015356
- Format
- Image (JPEG)
- PURL
- http://purl.flvc.org/ucf/fd/DP0015356
- Title
- Howe Scales Co. Tradecard.
- Date Created
- 1840s
- Identifier
- DP0015387
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015387
- Title
- Knox's gelatine.
- Date Created
- 1920s?
- Identifier
- DP0015493
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015493
- Title
- Baker's Delight Baking Powder.
- Identifier
- DP0015375
- Format
- Image (JPEG)
- PURL
- http://purl.flvc.org/ucf/fd/DP0015375
- Title
- "Topsies" and "Evas".
- Creator
-
Woody, Elizabeth, Muray, Nickolas
- Date Created
- 1940
- Identifier
- DP0015370
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015370
- Title
- Seal of North Carolina: Smoking Tobacco Marburg Bros.
- Date Created
- 1840-1880
- Identifier
- DP0015388
- Format
- Set of related objects
- PURL
- http://purl.flvc.org/ucf/fd/DP0015388
- Title
- "Dis sho' am good".
- Identifier
- DP0015342
- Format
- Image (JPEG)
- PURL
- http://purl.flvc.org/ucf/fd/DP0015342
