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Adamek, Jordan MatthewConcurrent Geometric Routing
PHD, Kent State University, 2017, College of Arts and Sciences / Department of Computer Science
Geometric routing is navigating the message on the basis of node coordinates. In ad hoc wireless networks, geometric routing allows stateless message navigation with minimum routing tables and constant message size. Concurrent geometric routing improves message delivery latency and reliability at the expense of greater message cost. In this dissertation, we study concurrent geometric routing solutions to geocasting, multicasting and multisource broadcast. For each solution, we present theoretical performance bounds as well as performance comparison through abstract and concrete simulation.

Committee:

Mikhail Nesterenko (Advisor); Gokarna Sharma (Committee Member); Hassan Peyravi (Committee Member); Volodymyr Andriyevskyy (Committee Member); Andrew Tonge (Committee Member)

Subjects:

Computer Science

Keywords:

distributed routing, ad hoc routing, wireless sensor networks, distributed algorithms, geometric routing, concurrent routing, multicast, geocast, multisource broadcast, worldSENS, concrete simulation, stateless algorithms

Venkata Narasimha, Koushik SrinathAnt Colony Optimization Technique to Solve Min-Max MultiDepot Vehicle Routing Problem
MS, University of Cincinnati, 2011, Engineering and Applied Science: Mechanical Engineering
This research focuses on solving the min-max Multi Depot Vehicle Routing Problem (MDVRP) based on a swarm intelligence based algorithm called ant colony optimization. A traditional MDVRP tries to minimize the total distance travelled by all the vehicles to all customer locations. The min-max MDVRP, on the other hand, tries to minimize the maximum distance travelled by any vehicle. The algorithm developed is an extension of Single Depot Vehicle Routing Problem (SDVRP) algorithm developed by Bullnheimer et al. in 1997 based upon ant colony optimization. In SDVRP, all the vehicles start from a single depot and return to the same depot, and solution aims at finding tours of vehicles so that every customer location is visited exactly once and that minimizes the total distance travelled. Building upon the SDVRP algorithm, this study first involves developing an algorithm for the min-max variant of SDVRP problem where the maximum distance travelled by any vehicle is minimized. Later, the algorithm has been extended to address the Multi Depot variant of this problem. In this case, vehicles can start from multiple depots unlike SDVRP case and have to come back to their respective depot of origin once they visit a set of customer locations. The min-max multi-depot vehicle routing problem involves minimizing the maximum distance travelled by any vehicle in case of vehicles starting from multiple depots and travelling to each customer location at least once. This problem is of specific significance in case of time critical applications such as emergency response in large-scale disasters, and server-client network latency. The proposed algorithm uses an equitable region partitioning approach aimed at assigning customer locations to depots so that MDVRP is reduced to SDVRP. A background study on swarm intelligence based optimization techniques, region partitioning methods, approximation algorithms and also various techniques of optimization has been included in this research. The proposed method has been implemented in Matlab for obtaining the solution for the min-max MDVRP with any number of vehicles and customer locations. A comparative study is carried out to evaluate the proposed algorithm’s performance with respect to a currently available algorithm in literature in terms of the optimality of solution and time taken to reach the solution. Based on an extensive simulation study, it has been demonstrated that the ant colony optimization technique proposed in this thesis leads to more optimal results as compared to an existing method.

Committee:

Manish Kumar, PhD (Committee Chair); Sundararaman Anand, PhD (Committee Member); Kelly Cohen, PhD (Committee Member)

Subjects:

Mechanics

Keywords:

Ant Colony Optimization;Min-Max Multi Depot Vehicle Routing Problem;Optimization Techniques;Vehicle Routing Problem;Min-Max Single Depot Vehicle Routing Problem;Combinatorial Optimization Problems;

WANG, HONGHAOAn Efficient and Secure Overlay Network for General Peer-to-Peer Systems
PhD, University of Cincinnati, 2008, Engineering : Computer Science and Engineering
Currently, Peer-to-Peer overlays can be classified into two main categories: unstructured and structured ones. Unstructured overlays are simple, robust, and powerful in keyword search. Structured ones can scale to very large systems in terms of node number and geography, and guarantee to locate an object within O(Log N) hops. However, both of them face difficulties in efficiency and security of overlays. For unstructured ones, the efficiency problem presented is poor scalability. For structured ones, it is long routing latency and enormous overhead on handling system churn. Moreover, both of them are vulnerable to malicious attacks. Peer-to-Peer overlays belong to application-level network. To a great extension, overlay network designs ignore physical characteristics. As the result, their structures are far from underlying physical network or the distribution pattern of overlay peers. These inconsistencies induce system common operations costly, such as routing and lookup. On the other hand, most peers are assumed to have uniform resources and similar behaviors. Thus, Peer-to-Peer protocols were designed to be symmetric. However, in the realistic environment, peers' resources and behaviors are highly skewed. Symmetric protocols actually compromise system performance. Frequently joining and leaving of peers generates enormous traffic. The significant fraction of peers with high latency/low bandwidth links increase lookup latency. Moreover, under the environment without mutual trust, Peer-to-Peer systems are very vulnerable for varied attacks because they lack a practical authentication mechanism. From a different perspective, this dissertation proposes to construct a highly efficient and secure Peer-to-Peer overlay based on the physical network structure of the Internet and network locality of overlay peers. By naturally integrating different network-aware techniques into the Peer-to-Peer overlay, a novel SNSA (Scalable Network Structure Aware) technique has been developed. It can provide accurate information of network locality of overlay peers and sufficient physical network structure of the Internet. Based on the valuable information, a unique Peer-to-Peer overlay, which can reflect network structure and locality of overlay peers, is constructed. Also, peers are assigned different roles by their resources and behaviors. Minor capable peers are involved in overlay core operations, such as routing and lookup. Major normal ones are organized into highly dependable teams, and assigned usual tasks, such as storing objects. Not only can this overlay support both structured and unstructured systems, but also the systems are highly efficient in routing and consuming much less bandwidth. As the observation that every peer must subject to the network configuration and administration imposed by ISPs, we propose to identify each peer by its physical network characteristic, net-print. Based on the SNSA technique and the net-print, a distributed authentication and secure routing mechanisms are developed under Peer-to-Peer environment. Beware of the fact that every overlay network maintains its own network proximity system. This dissertation proposes to build a common layer to provide such information for all overlays. By deeply analyzing requirements of current overlays, three kinds of primitives are designed to provide valued knowledge of physical network and overlay peers. Not only dose this method save network resource by eliminating duplicated probes, but it also provides an efficient way to share information between overlays.

Committee:

Dr. Yiming Hu (Advisor)

Subjects:

Computer Science

Keywords:

Peer-to-Peer; Overlay Network; Overlay Routing; Overlay Structure; Distributed Hash Table (DHT); Network Topology; Network Aware; Network Locality; Network Proximity; Network Security; Secure Routing; System Churn

Agarwal, Aarti SubhashUse of Query Control and Location for Routing in Mobile Ad Hoc Networks
MS, University of Cincinnati, 2002, Engineering : Computer Science
A mobile ad hoc network is a collection of wireless mobile nodes dynamically forming a network without the use of any existing network infrastructure or centralized administration. As the nodes are mobile, the network topology is dynamic leading to frequent unpredictable connectivity changes. It is critical to route packets to destinations effectively without generating excessive overhead. This presents a challenging issue for protocol design since the protocol must adapt to frequently changing network topologies in a way that is transparent to the end user. A class of routing protocols called on-demand protocols has received a lot of interest because of their low routing overhead. In this thesis, we study techniques that can reduce this routing overhead even further. The on-demand protocols depend on query floods to discover routes whenever a new route is needed. Network-wide floods incur substantial overhead. Techniques have been proposed to contain the flood in a limited region where a route to the destination is highly likely to be found. Techniques have also been proposed to reduce redundant broadcasts. We propose various mechanisms to improve on these existing techniques. We propose adaptive mechanisms that utilize prior routing histories, mobility pattern and network load to choose the area in which the query flood should be contained. In addition, we propose a technique that utilizes the neighborhood information to reduce or eliminate redundant broadcasts. We evaluate their performances in isolation and in tandem. In the next part of the thesis, we turn our attention to use of location information for routing. In has been shown in prior work that availability of location information can substantially reduce routing overheads. However, equipping all mobile nodes with GPS or other positioning system is not a cost effective proposition. We develop and evaluate a localization technique that can localize mobile nodes even when only a fraction of nodes in the network has direct access to location information. The rest of the nodes localize themselves by hearing radio beacons emitted from the nodes that have access to direct location information. We evaluate the localization accuracy using our technique via simulations. We show that the accuracy is better than the radio range even when only about 10% of the network nodes have direct access to location information. To be useful for routing, each node in the network must learn the location of every other node. However, disseminating this information sufficiently frequently can incur large overhead. To counter this, we develop a mobility prediction and location tracking model based on the dead-reckoning navigation technique. Here, both current location and movement model of mobile nodes are disseminated via flooding. Every other node is now able to track the movement with some accuracy until the movement model changes bstantially. We use this technique along with a geographic routing protocol to solve the unicast routing problem in ad hoc networks. Simulation studies show that it performs better than well-known on-demand routing protocols.

Committee:

Dr. Samir Das (Advisor)

Subjects:

Computer Science

Keywords:

Ad Hoc Networks; Routing; Dead Reckoning Model; Location based routing

Qi, YangjieFPGA Based High Throughput Low Power Multi-core Neuromorphic Processor
Master of Science (M.S.), University of Dayton, 2015, Electrical Engineering
The interest in specialized neuromorphic computing architectures has been increasing recently, and several applications have been shown to be capable of being accelerated on such platforms. This thesis describes the implementation of multicore digital neuromorphic processing systems on FPGAs. Static and Dynamic routing were used to allow communication between the cores on the FPGA. Several applications were mapped to the system including image edge detection, MNIST image classification, and biometric ECG classification. Given that all the applications were implemented on the same processor (hence same base Verilog code), with only a change in the synaptic weights and number of neurons utilized, the system has the capability to accelerate a broad range of applications.

Committee:

Tarek Taha (Committee Chair); Vijayan Asari (Committee Member); Eric Balster (Committee Member)

Subjects:

Computer Engineering; Electrical Engineering

Keywords:

FPGA; Neural Network; Static Routing; Dynamic Routing; Low Power; High Throughput

Zhang, HongweiDependable messaging in wireless sensor networks
Doctor of Philosophy, The Ohio State University, 2006, Computer and Information Science
The lack of a basic understanding of its essential components has been an obstacle for reliable, efficient, and reusable messaging services in sensornets. To address this problem, this dissertation identifies the basic components of sensornet messaging and studies the related algorithmic design issues. More specifically, we propose the messaging architecture SMA that consists of three components: traffic-adaptive link estimation and routing (TLR), application-adaptive structuring (AST), and application-adaptive scheduling (ASC). TLR deals with dynamic wireless links as well as the impact of application traffic patterns on link dynamics; AST and ASC control the spatial and temporal flow of data packets to support application-specific in-network processing and QoS requirements. To provide an instance of TLR, we propose the routing protocol Learn-on-the-Fly that solves the problem of precisely estimating wireless link properties in the presence of varying network conditions. Then, we study ASC from the perspective of in-network processing and QoS provisioning. Taking packet packing as an example of in-network processing, we study the problem of scheduling packet transmissions to improve messaging efficiency. For the basic problem of reliable and real-time data transport in event-detection sensornets, we propose the protocol Reliable-Bursty-Convergecast that innovates the window-less block acknowledgment scheme and the retransmission-aware differentiated contention control. The architecture SMA provides a framework for sensornet messaging, and the study of TLR and ASC provides algorithmic references for instantiating SMA. This part of the dissertation work has also provided dependable messaging services for several real-world sensornet systems. The second part of this dissertation addresses the challenges that complex faults and large system scale bring to the design of fault-tolerant protocols. To this end, we propose the concept of “local stabilization“. In a locally-stabilizing system, fault impact is locally contained around where the fault has occurred, and the time taken for the system to stabilize depends only on the size of the fault-perturbed region instead of the system size. For shortest path routing, a basic problem in messaging, we propose a locally-stabilizing protocol LSRP. The concept of local stabilization and the algorithmic approach of LSRP are generically applicable to other networking and distributed computing problems.

Committee:

Anish Arora (Advisor)

Subjects:

Computer Science

Keywords:

wireless sensor networks; messaging; wireless communication; resource constraints; application diversity; routing; data-driven link estimation and routing; transport; reliable and real-time data transport; in-network processing; scalable dependability

Gajurel, SanjayaMulti-Criteria Direction Antenna Multi-Path Location Aware Routing Protocol for Mobile Ad Hoc Networks
Doctor of Philosophy, Case Western Reserve University, 2008, Computer Engineering
In this paper, I develop Directional Antenna Multi-path Location Aware Routing (DA-MLAR) that is a location aware routing with directional antenna capability. DA-MLAR is a reactive routing protocol that minimizes the protocol overhead of other reactive routing protocols. DA-MLAR also improves the packet delivery ratio and end-to-end delay. The long radio transmission range obtained using directional antenna can decrease the number of network partitions there by reducing the number of rebroadcasts. It also reduces the number of routing hops. The directionality further reduces the network interferences by directing the beam only towards the receiving node and involving few intermediate nodes that are in the direction of receiving node. Two extensions of DA-MLAR - DA-MLAR with on demand adjustment of transmission power (DA-MLAR-ODTP) and beam width (DA-MLAR-ODBW) are proposed which further improves the performance metrics of ad hoc networks. In the first phase, the adjustment is made based on the calculated distance between the current sending node and the receiving node in the network. In the second phase, the adjustment also incorporates the effect of random Received Signal Strength (RSS) environment. Multi-objective approach is adopted to assess the network performance of MANET with complex, competing and conflicting objectives – maximizing packet delivery ratio, minimizing protocol overhead, and minimizing energy consumption. The preference of objectives depends on the type of application. In space, energy consumption is given more preference than other objectives. I have used the Normalized Weighted Additive Utility Function (NWAUF) approach to obtain the best alternatives. Through simulations using ns-2, I have demonstrated that DA-MLAR exhibits better network performance. Some performance metrics like packet delivery ratio and end-to-end delay have been significantly improved using DA-MLAR-ODTP and DA-MLAR-ODBW with check in protocol overhead and energy consumption. Subsequent simulation analysis using ns-2 is provided.

Committee:

Behnam Malakooti (Advisor)

Keywords:

Ad Hoc Network; Directional Antenna; Location Aware Routing Protocol; Mobile Ad-hoc Network; Network Performance Computation and Evaluation; On Demand Routing; Beam Width adjustment; Transmission power adjustment; Multi-objective Analysis

Tahboub, Omar YTHE PRINCIPLE OF DATA FLOW EQUILIBRIUM FOR RESERVOIR MINIMIZATION IN PERIODIC INTERMITTENT NETWORKS
PHD, Kent State University, 2013, College of Arts and Sciences / Department of Computer Science
Network with link intermittency is a growing class of emerging networks of interest. Such networks exhibit long data transfer delay caused by discrete communication services. A particular challenge in such networks is the requirement of very large intermediate storage – or “reservoir” - in all the transit elements at their core infrastructure. In this dissertation, we investigate a forwarding principle called “data flow equilibrium,” which aims to substantially reduce transit reservoir consumption compared with conventional Classic IP data forwarding in periodical intermittent networks. We show that this principle can drastically reduce the transit reservoir requirement without degrading the delay. We validate the result in two ways: analytical and simulation. First, we analytically derive the transit reservoir capacity requirement and transfer delay upper bounds of a single dataflow and critical hop case both, with the equilibrium principle and without it. We devised a data flow equilibrium algorithm, which aims to gear link-hop capacities to preserve transit reservoir. Second, we validated by simulation the analytical reservoir capacity requirement and transfer delay upper bounds for the general multi-flow case with and without data flow equilibrium. We experiment a data backup drill scenario over a simulated network, whose links are periodically intermittent. We devised two types of Constraint Resource Planning (CRP) routing solvers: Classic and Optimized. Classic solvers are based on the conventional greedy routing and Classis IP forwarding. Optimized solvers are based on scheduling-based intelligent routing and data flow equilibrium forwarding. Simulation results have revealed that data flow equilibrium achieves a near-optimal performance, where the majority of reservoir demands were within their analytical upper bounds. We also shown that data flow equilibrium did not adversely impact data flow transfer delay. Surprisingly, the presence of data flow equilibrium played the deciding factor in the achievement of perfect completion schedulability. Finally, the most distinguishing aspect of this work is the formal treatment of network intermittency, which, has not been undertaken before.

Committee:

Javed Khan, PhD (Advisor)

Subjects:

Computer Engineering; Computer Science; Electrical Engineering

Keywords:

Networking; Routing; Forwarding; Data Flow; Equilibrium; Protocol

Alshraiedeh, Juman Wear-out Leveling in Network on Chips (NoCs)
Master of Science (MS), Ohio University, 2017, Electrical Engineering & Computer Science (Engineering and Technology)
According to Moore's Law, the number of transistors on a single chip doubles every two years, allowing tens or even hundreds of cores to be integrated. As multicores communicate with memory, the underlying Network-on-Chip (NoC) experiences different stress levels due to asymmetric traffic patterns and complex routing algorithms. Unfortunately, the growth in the number of transistors in NoCs will significantly impact both reliability (physical failures) and aging (uneven utilization) due to the increasing effects of Electromigration (EM), Hot carrier injection (HCI) and Negative Bias Temperature Instability (NBTI). A novel in-flight, adaptive, routing algorithm is presented to reduce the accumulation of EM, HCI, and NBTI effects on the lifetime of NoC. The proposed routing algorithm is based on a new metric called Packet-Per-Port (P3) which equalizes the stress throughout the network. The net impact is that the network components such as the links and the routers will age evenly and thereby improve NoC reliability and maximize the lifetime of the chip. Results indicated that for Splash-2 traces, we observe 7.3% to 13.7% energy per bit reduction and up to 6.23% improvement in the transistor reliability when compared to Dimensional Order Routing (DOR) on 8x8 mesh. P3 was also compared to age-adaptive routing proposed in [1] and we observe 1% improvement in reliability and up to 11% energy per bit reduction.

Committee:

Avinash Kodi (Advisor)

Subjects:

Computer Engineering; Electrical Engineering

Keywords:

Aging; NBTI; HCI; Electromigration; Routing Algorithm; Reliability

Iyengar, NavneetProviding QoS in Autonomous and Neighbor-aware multi-hop Wireless Body Area Networks
MS, University of Cincinnati, 2015, Engineering and Applied Science: Computer Science
Continued evolution of Wireless Body Area Networks (WBANs) has made effective monitoring of vital parameters of a person much faster and efficient, thereby providing better personal healthcare. Sensor nodes of a WBAN acquire critical physiological parameters like heartbeat, neural activity, limb motion, muscle movement and fatigue, temperature, etc. that are monitored by a physician. Important factors in the acceptance of WBAN performance are energy efficiency and the Quality of Service (QoS) supported for such critical data that impact human lives. The sensor nodes of a WBAN are highly constrained in terms of their battery life. Most of the work till date on WBANs uses a star topology which employs single hop communication. This work discusses various factors that affect energy efficiency in a WBAN and establishes the need for a multi-hop tree based topology. It also studies the need for QoS in WBANs and existing support provided by the current Body Area Sensor Network (BASN) Standard. This thesis tackles the all important challenge of providing QoS in autonomous and neighbor-aware multi-hop WBANs in significant detail spread across multiple chapters. In case of independent, autonomous multi-hop WBANs, the aforementioned issue is resolved by implementing a two layer priority-mapping scheme over a reactive Media Access Control (MAC) layer designed to alter durations of the access phases involved as per QoS requirement. In the case of neighbor-aware WBANs, a framework is defined under which a cooperative inter-WBAN routing scheme is implemented through power based weight assignment and fault detection is carried out by employing Kosaraju's two-pass algorithm that discovers the strongly connected components in the network deployment graph.

Committee:

Dharma Agrawal, D.Sc. (Committee Chair); Raj Bhatnagar, Ph.D. (Committee Member); Prabir Bhattacharya, Ph.D. (Committee Member)

Subjects:

Computer Science

Keywords:

Wireless Body Area Networks - WBANs;Quality of Service - QoS;Reactive Media Access Control;Multi-hop network topology;Cooperative inter- Neighbor-Aware WBAN routing;Fault Detection and Localization with Recovery

Hasan, Md. RaqibulMulti-core Architectures for Feed-forward Neural Networks
Master of Science (M.S.), University of Dayton, 2014, Electrical Engineering
Power density constraints and processor reliability concerns are causing energy efficient processor architectures to gain more interest in recent years. One approach to reduce processor power consumption is through the use of specialized multi-core architectures that provide significant speedups for neural network applications. Several studies have shown that a large variety of processing tasks can be represented as neural networks. This thesis examines specialized multi-core processor designs for such specialized architectures. Both SRAM and memristor based specialized neural core designs are studied. The thesis also examines the on-chip routing needed to enable communications between cores. The routing bandwidth needed to enable processing of large multi-layered feed forward neural networks is studied. Two routing bandwidth models were developed for mesh interconnection networks: one examined sending neuron outputs from one layer to the next, while the other examined the streaming of synaptic weights from off-chip memory. The models were validated through simulations. Both static and dynamic routing approaches for large multi-core feed forward neural network accelerators were examined. We have observed that the accumulated bandwidth requirement in the on-chip network to access off-chip data is much greater than bandwidth required to send neuron outputs between cores. In almost all cases, static routing was significantly more efficient than dynamic routing, requiring both lower area and power. We compared our proposed SRAM and memristor based digital systems to more traditional HPC systems. Two commodity high performance processors were examined: a six core Intel Xeon processor, and an NVIDIA Tesla M2070 GPGPU. Care was taken to ensure the code on each platform was very efficient: multi-threaded and accounting for vector parallelism on the Xeon processor, and a high device utilization CUDA program on the GPGPU. Our results indicate that the specialized systems can be between two to five orders more energy efficient compared to the traditional HPC systems.

Committee:

Tarek Taha, Dr. (Committee Chair); Vijayan Asari, Prof. (Committee Member); John Loomis, Dr. (Committee Member)

Subjects:

Electrical Engineering

Keywords:

Multi-core architectures, neuromorphic architecture, on-chip routing, memristor crossbar, specialized core

Kallio, Rebecca MaeEvaluation of Channel Evolution and Extreme Event Routing for Two-Stage Ditches in a Tri-State Region of the USA
Master of Science, The Ohio State University, 2010, Food, Agricultural and Biological Engineering
There were five objectives addressed in this thesis: 1) evaluation of the evolution of two-stage ditches in a tri-state region in the upper Midwest, USA; 2) developing a unit hydrograph that accounts for subsurface drainage discharges into surface collection ditches; 3) evaluation and/or enhancement of the developed unit hydrograph method for extreme events; 4) estimation, at a reach scale of, the percentage of peak flood reduction in five constructed two-stage ditches; and 5) estimation of the influence on flow discharges of constructing two-stage channels along all surface ditches within a watershed. Objective 1 or channel evolution evaluation was performed on 5 two-stage ditches from Michigan, Ohio and Indiana with watershed sizes ranging between 2 to 6 mi2. The following ditches were evaluated: Crommer Ditch in Hillsdale County, Michigan; Klase Ditch in Shelby County, Ohio; Bull Creek of Hancock in Ohio; Creel Ditch in Steuben County, Indiana; and Shatto Ditch in Kosciusko County in Indiana. System evolution was evaluated to determine if ditches were assuming a state of quasi-equilibrium or defined as the morphological change in the stream channel that occurs as a stream seeks for greater channel stability. Evolution evaluation indicated that Crommer Ditch was in a state of quasi-equilibrium. Klase Ditch was evolving towards a state of quasi-equilibrium. Bull Creek downstream segment was in a state of quasi-equilibrium; whereas, the upstream segment was still evolving. At Shatto Ditch may be evolving towards a state of quasi-equilibrium. The double-triangle unit hydrograph method was used to modeling the hydrology of agricultural ditches receiving subsurface agricultural drainage. Gowda et al. (1999) double triangle unit hydrograph method, and four curve fitting techniques were evaluated to determine which parameters best account of subsurface drainage. Curve fitting technique 4, which had neglected the watershed land properties, best predicted the measured storms at Crommer Ditch, Klase Ditch, and Bull Creek. Curve fitting technique 4, as well as, two additional unit hydrograph methods were examined to model extreme events in agricultural ditches receiving subsurface, agricultural drainage. Unit hydrograph method 2 was a single triangle with calibrated peak discharges. Unit hydrograph method 3 was the hydrograph shape from curve fitting technique 4 with calibrated peak discharges. Unit hydrograph method 3 was effective at modeling extreme events in the ditches because it had retained the calibrated peak discharges and gave base times that characteristic of systems receiving subsurface drainage. Hydraulic routing was performed using HEC-RAS software to determine the attenuation of peak discharge and stage occurrence at the 5 constructed two-stage ditches. The results indicated little reduction in peak discharge; however, substantial reductions in the peak stage and flow velocities occurred. A second study, at Bull Creek determined the impact on peak discharge and stage when converting the entire upstream watershed into a two-stage ditch, with varying floodplain storage. The results indicated a large decrease in the peak stage and flow velocities and an increase in the peak discharge. Additionally, the backwater conditions resulted in an increase in peak discharge when floodplain storage increased.

Committee:

Andy D. Ward, PhD (Advisor); Jon D. Witter, PhD (Committee Member); Larry C. Brown, PhD (Committee Member)

Subjects:

Agricultural Engineering

Keywords:

two-stage ditches; channel evolution; hydrulic routing

Venkatraman, LakshmiSECURED ROUTING PROTOCOL FOR AD HOC NETWORKS
MS, University of Cincinnati, 2001, Engineering : Computer Science
In this thesis, we have analyzed the threats to the routing protocols in ad hoc wireless networks and have put forth methods to enhance secure routing. Mobile ad hoc networking is a new emerging field with its potential applications in extremely unpredictable and dynamic environments. Due to such characteristics, these networks have much harder security requirements than the traditional, wired and static Internet. Efficient and effective routing in such networks is an especially hard task to accomplish securely, robustly and efficiently at the same time. One of the most severe threats to routing in such networks is the possibility of compromised nodes, which inflict unpredictable and undetectable Byzantine failures. The contemporary routing protocols do seem to manage the dynamically changing conditions rather well. In contrary, they offer either no security mechanisms at all, or have only partial solutions for protecting the routing. We believe that security schemes should be integrated with the routing protocols because the kinds of attacks and their solutions would differ from one protocol to another. Moreover, the imple-mentation will be optimal if it is designed for a specific protocol. We have presented a scheme for reactive routing protocols, specifically AODV, that performs the dual functions of preventing external attacks and also detecting compromised nodes. External attacks are prevented by means of authentication techniques that rely on mutual trust between nodes. We have also minimized the overhead involved in authentication. We have identified various forms of misbehaviors and have proposed solutions for certain deterministic ones. When either form of attack is detected, the system responds suitably to negate the effect of these attacks and also prevent future threats from the same nodes. Besides routing security, we have studied the issue of data authentication for hierarchical ad hoc networks and have proposed a data authentication scheme. In our scheme each cluster head acts as the certification authority for its cluster members.

Committee:

Dharma Agrawal (Advisor)

Keywords:

AODV; Authentication; Routing-table consistency; Heirararchical; Replay

Sehgal, RahulGreedy routing in a graph by aid of its spanning tree: Experimental results and Analysis
MS, Kent State University, 2009, College of Arts and Sciences / Department of Computer Science

In wireless networks, greedy routing is a method of routing message from source to destination in which the current vertex, holding the message, sends the message to its neighbor whose geographic distance from destination is minimum among all its neighbors. This method often suffers a problem of local minima. A local minimum is a situation in which the vertex which is holding the message is closer to the destination than any of its neighbors and destination is not its neighbor. Various methods have been proposed for getting out of local minima but they have different limitations imposed on them.

Recently, more robust solutions for getting out of local minima have been proposed based on the idea of assigning to each vertex a virtual coordinate in some metric space. One of the methods is greedy routing using an embedding of the graph topology into the hyperbolic plane. This method uses a spanning tree of the graph, embedded into the hyperbolic plane, and guarantees that the message will always reach the destination. However, it also has a limitation that the message may take a very long route even if a shorter route exists in the graph.

In our work, we propose a method of greedy routing in a graph with the aid of its spanning tree and we investigate the problem of selecting a "good" spanning tree in a graph such that the greedy routing using this tree guaranties relatively short greedy routing paths. The experiments are performed on different types of graphs, like Random graphs, Unit Disk graphs and Power Law graphs, and different densities (dense, average dense and sparse). The spanning trees used for greedy routing are Breadth First Search, Depth First Search, Minimum Spanning Tree (Prim's algorithm), Dijkstra's algorithm (weighted variant of breadth first search) and Hamiltonian path (weighted variant of Depth First Search). The experiments results compare greedy paths generated by these spanning trees in terms of stretch factor, and give preferences for selecting a spanning tree for greedy routing for a given graph type and graph's density type.

Committee:

Feodor Dragan, PhD (Advisor); Hassan Peyravi, PhD (Committee Member); Ruoming Jin, PhD (Committee Member)

Subjects:

Computer Science

Keywords:

Greedy Routing

Prakash, AbhinavAnonymous and Secure Communication in a Wireless Mesh Network
MS, University of Cincinnati, 2012, Engineering and Applied Science: Computer Science

With the rapid advancement of different types of wireless technologies the problem arose of combining them together to provide improved bandwidth and enhanced throughput. The answer came out in the form of a Wireless Mesh Network (WMN). A typical WMN is made up of mesh routers and mesh clients where mesh routers have somewhat limited mobility and they form the backbone of the network whereas mesh clients are allowed to be highly mobile or completely stationary or somewhere in between. This forms a very versatile network which allows clients with different levels of mobility, interface and bandwidth requirements to be a part of the same network. The communication can be achieved by directly communicating with the router by being in its range or in an ad hoc fashion through several hops. A WMN is mainly designed to be self-configured and self-adjusting dynamically. This ensures large network coverage with minimum infrastructure requirements, hence low cost. Although a WMN gives multifold advantages it is also vulnerable to several security and privacy threats being a dynamic open medium. Different types of clients such as laptops, cell phones, smart devices can join or leave the network anytime they wish. This opens up issues like fake registrations and packet sniffing.

This work deals with the issues of security and privacy separately in two parts in great detail by simulating countermeasures for different kinds of attacks in a WMN. The first part mainly deals with creating a perfectly secure network for safe communication by using a bi-variate polynomial scheme for low overheads instead of a public-private key mechanism. The second part deals with making any communication in the network anonymous by hiding the node initiating the session by using redundancy at the cost of some associated overheads.

Committee:

Dharma Agrawal, DSc (Committee Chair); Yizong Cheng, PhD (Committee Member); Chia Han, PhD (Committee Member)

Subjects:

Computer Science

Keywords:

Mesh Networks; Security; Onion Routing; Bivariate Polynomial Function; Backbone; Hybrid Networks

Todakar, OnkarFPGA-based fault tolerant design and deterministic routing-based synthesis for Digital Microfluidic Biochips
MS, University of Cincinnati, 2015, Engineering and Applied Science: Computer Engineering
Microfluidic biochips have been widely used as an alternative to traditional laboratory equipment. They offer a considerable advantage over traditional equipment when the reduction in cost, area and efforts is considered. A lot of research has been done on designing general purpose, cost-effective architectures and also on methods to automate the mapping of assays on to these biochips. Biochips are susceptible to failures due to various reasons such as manufacturing defects, wear and tear etc. We propose a fault tolerant scheduling algorithm which reconfigures the DMFBs in the presence of such faults. A faulty module (for example a mixer with 2x5 electrodes) can be reconfigured using a droplet routing approach that routes droplet, avoiding the faulty electrodes. We observe an average 23% reduction in the assay completion time, when compared to a DMFB with a faulty module. We further extend this routing-based approach to propose an algorithm to map assays to DMFBs. Most of the previous work on mapping assays assumes the presence of virtual modules on DMFBs and schedules operations on them. In our work we propose a deterministic greedy algorithm that routes the droplet on a random sequence of electrodes rather than restricting it to a virtual module to execute the operation. Our algorithm moves the droplets on the DMFB such that the operation is completed in the minimum possible time. The results show approximately 43% reduction in assay completion time, when compared to traditional module based mapping algorithm on a FPGA style DMFB array, and 26% improvement compared to the randomized routing - based synthesis algorithm GRASP.

Committee:

Wen-Ben Jone, Ph.D. (Committee Chair); Rashmi Jha, Ph.D. (Committee Member); Ian Papautsky, Ph.D. (Committee Member)

Subjects:

Engineering

Keywords:

Routing-based synthesis;DMFBs;Fault-tolerant

Patel, Chintankumar R.Development of the Simulation Based Integrative Decision Support Framework for Flexible Manufacturing System with Real Time Process Plan Selection
Master of Science (MS), Ohio University, 2010, Industrial and Systems Engineering (Engineering and Technology)
In order to maximize FMS benefits, it is necessary to consider real-time decision making process, based on updated information about the FMS status. This thesis reports on a simulation study of a sample FMS with integration of two flexibility types: routing flexibility and scheduling flexibility. Integrative framework developed in this thesis integrates process planning module and simulated FMS module through real time data exchange. FMS is simulated in Arena with four different routing decision policies: a) static best, b) static random, c) routing dynamic, and d) feature focused dynamic. Simulation model has been executed on the same data set for four mentioned routing decision policies and for four dispatching policies (FIFO, SPT, SIPT, and LIPT). Results of each simulation run in terms of five performance measures have been compared in order to determine best routing alternative selection policy, corresponding dispatching policy, and identify the best combination of those two policies.

Committee:

Dušan Šormaz (Advisor)

Subjects:

Engineering; Industrial Engineering

Keywords:

Discrete event simulation; Arena; Decision support framework; Flexible manufacturing system; Process plan; Dispatching rule; Routing policy

Ganapathysubramanian, KarthickDevelopment and Evaluation of Order Batching Procedures for a Distribution Center
Master of Science (MS), Ohio University, 2005, Industrial and Manufacturing Systems Engineering (Engineering)

The rise of e-commerce in warehouses and encouraging customers to order online has not only increased sales but also handling of products at an order picking warehouse since such orders are often only a few items, rather than cases or a pallet of items.

The objective of this thesis is to develop and evaluate three methods to create waves that will increase the number of orders shipped per week (throughput of orders attended). A continuous updating of new order entries and a class-based layout for storage was considered.

The Earliest Due Date Method includes orders with a priority on due dates. The Savings Method includes orders with the maximum amount of savings attained in terms of picking tour time. The Smallest Increase Method includes orders with the smallest increase in route tour time. It is shown that by implementing the MS method or the SI method leads to an increased number of orders shipped per week.

Committee:

Dale Masel (Advisor)

Keywords:

Distribution Center; Batching; Routing; Storage

JAIN, NEHAENERGY AWARE AND ADAPTIVE ROUTING PROTOCOLS IN WIRELESS SENSOR NETWORKS
PhD, University of Cincinnati, 2004, Engineering : Computer Science and Engineering
Recent technological advances have enabled distributed micro-sensing for large scale information gathering through a network of tiny, low power devices or nodes equipped with programmable computing, multiple sensing and communication capabilities. This network of sensor nodes, known as a wireless sensor network, has revolutionized remote monitoring applications because of its ease of deployment, ad hoc connectivity and cost-effectiveness. In this dissertation, we design distributed routing protocols for minimizing energy consumption in a sensor network. There are two main contributions of this work. The first contribution is the design of an energy aware multiple path routing protocol to route heavy data traffic between a source and a destination node in a sensor network. The protocol spreads the routing load between the source and destination nodes over a large number of sensor nodes to minimize disparity in the energy levels of the sensor nodes. We also grade the multiple paths based on their route length to support time critical queries on the shortest available paths. The second contribution is the design of a communication architecture that supports distributed query processing to evaluate spatio-temporal queries within the network. We represent these queries by query trees and distribute query operators to appropriate sensor nodes. As operator execution demands high computation capability, we propose use of a heterogenous sensor network where query operators are assigned to sparsely deployed resource-rich nodes within a dense network of low power sensor nodes. We design an adaptive, decentralized, low communication overhead algorithm to determine an operator placement on the resource-rich nodes in the network to minimize cost of transmitting data in the routing tree constructed to continuously retrieve data from a set of spatially distributed geographical regions to the sink. To the best of our knowledge, this is the first attempt to build an energy aware routing infrastructure to enable in-network processing of spatio-temporal queries. In order to maximize energy savings the proposed multiple path routing protocol can be used to route data between the nodes that form the routing tree.

Committee:

Dr. Dharma Agrawal (Advisor)

Subjects:

Computer Science

Keywords:

Wireless Sensor Networks; Routing Protocols; Energy Aware; Decentralized algorithms

Chang, Chia-ShengA period vehicle routing problem with time windows and backhauls
Doctor of Philosophy, Case Western Reserve University, 1993, Operations Research
This dissertation develops solution procedures for the Period Vehicle Routing Problem with Time-windows and Backhauls (PVRPTWB). The problem includes many real-world considerations, such as time-window constraints, driver waiting cost, backhauls, layovers, and others, simultaneously. A mathematical formulation for the PVRPTWB is given. An exact algorithm based on a set-partitioning formulation is presented. The algorithm combines column generation with a branch-and-bound approach. The columns are generated by solving a shortest-path problem with additional side constraints. Heuristic algorithms are also given. Extensive computational test have been performed. Results on a real-world case study are also included. These results indicate that this approach is particularly efficient when the time-window constraints are relatively tight.

Committee:

Daniel Solow (Advisor)

Keywords:

period vehicle; routing problem; time windows; backhauls

Mamidisetty, Kranthi KumarGeneralizing Contour Guided Dissemination in Mesh Topologies
Master of Science, University of Akron, 2008, Electrical Engineering
Wireless mesh topologies are important for a variety of engineered systems. Despite the mesh connectivity, where every node is connected to several neighbors, the number of shortest paths between a pair of nodes is limited by the relative locations of the nodes. Prior work in this area has resulted in the characterization of the structure of the shortest paths between a pair of nodes in a regular mesh topology in which each node has eight neighbors. This thesis presents new results that characterize the structure of the union of all the shortest paths between a pair of nodes in mesh topologies where each node has three, four, or six neighbors. When a source sends M messages to the sink, and every node spreads the messages over every available shortest path uniformly, it is shown that nodes along one shortest path will always handle more messages than the nodes along other shortest paths. Optimal rules which ensure that nodes at a same distance from the source along different paths handle roughly the same number of messages, are presented. Simulation results that validate the analytical conclusions are also presented. In the future, similar methods for dissemination can be developed for general topologies.

Committee:

Shivakumar Sastry, PhD (Advisor); James Grover, PhD (Committee Member); S.I. Hariharan, PhD (Committee Member)

Subjects:

Electrical Engineering

Keywords:

Contour; Dissemination; Mesh Topologies; Routing; Neighbor; QoS

RAJSHIVA, KIRTIMAANPERFORMANCE ENHANCEMENTS FOR Ad Hoc NETWORKS USING MOBILITY-LOCATION INFORMATION
MS, University of Cincinnati, 2005, Engineering : Computer Science
Performance of a mobile ad hoc network (MANET) depends directly on the quality of routes selected by the routing protocol at the network layer and the packet transmission efficiency of the MAC layer protocol. The network layer routing protocol used in a MANET does not truly reflect the exact network topology as there is always a delay between topology changes in the network due to user’s mobility and its corresponding routing table changes at the network layer by the routing protocol. Therefore, high user mobility in MANETs causes frequent link breaks when a pair of mobile user nodes, which have moved out of the transmission range of each other but are still shown as neighbors by the routing table, try to communicate with each other. This causes several unnecessary retransmissions between them at the MAC layer before the link is declared dead. Such retransmissions result in inefficient network resource utilization as power and bandwidth are wasted in transmission attempts by the sender node to send packet to the out-of-range receiver node. This research work proposes enhancements for the MAC layer protocol with associated changes at the network layer routing protocol that reduce link break probability, collision probability faced by a transmission, and solve the channel under-utilization problem because of the exposed terminal problem. The proposed schemes, i.e., location prediction check, transmission awareness and service differentiation, use current ongoing transmission information contained in the MAC layer protocol’s handshake packets with piggybacked transmitting node’s mobility-location information. A higher overall performance is achieved with the proposed implementation of the routing protocol over the MAC layer protocol in terms of throughput, power utilization and better quality of service (QoS).

Committee:

Qing-An Zeng (Advisor)

Subjects:

Computer Science

Keywords:

Ad Hoc networks; DSDV routing protocol; CSMA/CA MAC protocol; Cross layer; Location prediction techniques; exposed terminal problem

Aleman, Rafael E.A Guided Neighborhood Search Applied to the Split Delivery Vehicle Routing Problem
Doctor of Philosophy (PhD), Wright State University, 2009, Engineering PhD

The classic vehicle routing problem considers the distribution of goods to geographically scattered customers from a central depot using a homogeneous fleet of vehicles with finite capacity. Each customer has a known demand and can be visited by exactly one vehicle. Each vehicle services the assigned customers in such a way that all customers are fully supplied and the total service does not exceed the vehicle capacity. In the split delivery vehicle routing problem, a customer can be visited by more than one vehicle, i.e., a customer demand can be split between various vehicles. Allowing split deliveries has been proven to potentially reduce the operational costs of the fleet.

This study efficiently solves the split delivery vehicle routing problem using three new approaches. In the first approach, the problem is solved in two stages. During the first stage, an initial solution is found by means of a greedy approach that can produce high quality solutions comparable to those obtained with existing sophisticated approaches. The greedy approach is based on a novel concept called the route angle control measure that helps to produce spatially thin routes and avoids crossing routes. In the second stage, this constructive approach is extended to an iterative approach using adaptive memory concepts, and then a variable neighborhood descent process is added to improve the solution obtained.

A new solution diversification scheme is presented in the second approach based on concentric rings centered at the depot that partitions the original problem. The resulting sub-problems are then solved using the greedy approach with route angle control measures. Different ring settings produce varied partitions and thus different solutions to the original problem are obtained and improved via a variable neighborhood descent.

The third approach is a learning procedure based on a set or population of solutions. Those solutions are used to find attractive attributes and construct new solutions within a tabu search framework. As the search progresses, the existing population evolves, better solutions are included in it whereas bad solutions are removed from it. The initial set is constructed using the greedy approach with the route angle control measure whereas new solutions are created using an adaptation of the well known savings algorithm of Clarke and Wright (1964) and improved by means of an enhanced version of the variable neighborhood descent process. The proposed approaches are tested on benchmark instances and results are compared with existing implementations.

Committee:

Raymond R. Hill, PhD (Advisor); Xinhui Zhang, PhD (Committee Member); James T. Moore, PhD (Committee Member); George G. Polak, PhD (Committee Member); Zhiqiang Wu, PhD (Committee Member)

Subjects:

Engineering; Industrial Engineering; Operations Research; Transportation

Keywords:

vehicle routing; split delivery; variable neighborhood descent; adaptive memory; greedy approach; diversification; tabu search

Sridharan, MukundanDesign of Mobile and Static Sensor Fabrics
Doctor of Philosophy, The Ohio State University, 2011, Computer Science and Engineering

Over the last few years, two fundamental changes have happened in the domain of Wireless Sensor Networks (WSN). One, the applications have ceased to be edge-alone and have morphed into a edge-enterprise co-design. Two, sensor networks are beginning to be shared by a number of stake holders, with varied requirements. This translates into three key requirements for today's WSNs. One, the networks to be designed should be customizable and repurposeable on short notice. Two, the networks should be sliceable--the ability to deploy and run multiple applications simultaneously. Three, the networks need to be designed in such a way as to enable interaction, collaboration and federation with other networks or agents outside of the network to achieve some common goal. This has led to the re-examination of the application development model for WSNs.

This dissertation proposes an architecture called the fabric model for designing WSN as generic sensing networks, on which applications can be tailored. The model focuses on standardizing services and APIs that are common to most sensor fabrics, so that the common services can be reused across fabrics.

We illustrate the usefulness of the fabric model by specifying and building three different fabrics, but by reusing a number of common services. The three fabrics, Kansei--a sensor testbed with a wired control channel, PeopleNet--a mobile wireless network and VillageNet--an intermittently-connected mobile network, use the same fault-tolerant fabric manager and I/O services. As one of the key contributions we present the architecture for a fault-tolerant, scalable and autonomous fabric manager that can manage thousands of sensor nodes.

While we reuse a number of services in PeopleNet and VillageNet from Kansei, a few significant challenges remain in designing mobile WSN fabrics. An energy constrained multi-hop mobile network, such as, PeopleNet and VillageNet, needs an efficient and reliable routing protocol. Thus, we make two key contributions in the mobile routing space. We have designed & implemented the Asymmetric Event-driven Routing (AER) service, which provides energy efficient messaging service in a slowly mobile network, and the Reliable Energy Aware Predictive Routing (REAPER) service, which provides end-to-end messaging for intermittently-connected mobile networks.

The fabric model provides a number of advantages in designing customizable fabrics and its services based design lends itself to WSN federations naturally. But, a number of other challenges remain in federating WSN fabrics. We present KanseiGenie, a GENI-compliant software architecture for federating geographically separated sensor fabrics and to provide the user with a common interface to program across the federated fabrics. KansiGenie, builds on top of the fabric model and tackles issues related to resource and experiment specification in federating sensor fabrics. We also demonstrate through WEAVE--a domain specific service--how a federated application can be stitched using multiple sensor fabrics.

As sensor networks become ubiquitous and federated, we hope and believe that our work in this dissertation will serve as one of the cornerstones, which will encourage further research in the design and integration of sensor networks.

Committee:

Anish Arora, PhD (Committee Chair); Prasu Sinha, PhD (Committee Member); Rajiv Ramnath, PhD (Committee Member)

Subjects:

Communication; Computer Engineering; Computer Science; Experiments; Information Science

Keywords:

WSN; sensor fabric; fabric model; Asymmetric Event-Driven Routing; DTN; REAPER; invariant-based fault model; autonomic manager; WSN federation; GENI

Shukla, ManishTCP Performance With Multipath Routing in Wireless Ad Hoc Networks
MS, University of Cincinnati, 2003, Engineering : Computer Science
Majority of applications on the Internet today use TCP for reliable communication. TCP has been designed for and fine tuned to wired environments, but recent studies have shown that its performance suffers in wireless network environments, particularly in ad hoc networks because of the presence of multiple wireless hops. Routing has been the most focused area of research in recent years in wireless ad hoc networking area. Many on-demand routing protocols have been proposed to improve robustness in the face of link and route failures and facilitate packet transmission. Using multiple paths to route packets is one of them. We examine the performance of the TCP protocol with multiple paths in mobile ad hoc networks (MANETs). We set up multiple routes between the TCP source and destination either manually or using an on-demand multipath routing protocol, and forward packets on both paths to reduce the load on one single path. Ordinarily one would expect the multiple paths to reduce conflict between TCP data and acknowledgement packets thus giving better overall performance. Our results do incidate that TCP performance with multipath routing shows some improvement for long routes; however, shorter routes may experience slight degradation in performance as compared to single path routing. This observation remains true even when contention-based scheduling is used to schedule packets on different paths, or the multiple routes are chosen such that they have a minimum radio interference among themselves. We conclude that the TCP could gain only limited benefits with multipath routing.

Committee:

Dr. Samir R. Das (Advisor)

Keywords:

TCP over wireless; TCP over AD HOC Networks; multipath routing; TCP performance with multipath; multipath in wireless network

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