Engineering Commons^™

Using Pareto Fronts To Evaluate Polyp Detection Algorithms For Ct Colonography, Adam Huang, Jiang Li, Ronald M. Summers, Nicholas Petrick, Amy K. Hara

Electrical & Computer Engineering Faculty Publications

We evaluate and improve an existing curvature-based region growing algorithm for colonic polyp detection for our CT colonography (CTC) computer-aided detection (CAD) system by using Pareto fronts. The performance of a polyp detection algorithm involves two conflicting objectives, minimizing both false negative (FN) and false positive (FP) detection rates. This problem does not produce a single optimal solution but a set of solutions known as a Pareto front. Any solution in a Pareto front can only outperform other solutions in one of the two competing objectives. Using evolutionary algorithms to find the Pareto fronts for multi-objective optimization problems has been …

Cosign: A Parallel Algorithm For Coordinated Traffic Signal Control, Shih-Fen Cheng, Marina A. Epelman, Robert L. Smith

Research Collection School Of Computing and Information Systems

The problem of finding optimal coordinated signal timing plans for a large number of traffic signals is a challenging problem because of the exponential growth in the number of joint timing plans that need to be explored as the network size grows. In this paper, the game-theoretic paradigm of fictitious play to iteratively search for a coordinated signal timing plan is employed, which improves a system-wide performance criterion for a traffic network. The algorithm is robustly scalable to realistic-size networks modeled with high-fidelity simulations. Results of a case study for the city of Troy, MI, where there are 75 signalized …

An Operational Model For Mobile Sensor Cloud Management, Indrajeet Kalyankar

Electrical & Computer Engineering Theses & Dissertations

Mobile sensors provide a safe, cost effective method for gathering information in hazardous environments. When the hazardous environment is either unexplored, such as the surface of Mars, or unanticipated, such as the result of chemical contamination, it is desirable for a system to gather information with a minimal amount of outside control (localization, decision control, etc.) and prepositioned sensors. If one takes a look at the number of the sensors deployed on a scale, at the lower end is the sole, multipurpose sensor unit. The upper end deals with hordes of inexpensive, expendable sensors. In the middle, a cluster of …

An Adaptive Algorithm To Identify Ambiguous Prostate Capsule Boundary Lines For Three-Dimensional Reconstruction And Quantitation, Rania Yousry Hussein

Electrical & Computer Engineering Theses & Dissertations

Currently there are few parameters that are used to compare the efficiency of different methods of cancerous prostate surgical removal. An accurate assessment of the percentage and depth of extra-capsular soft tissue removed with the prostate by the various surgical techniques can help surgeons determine the appropriateness of surgical approaches. Additionally, an objective assessment can allow a particular surgeon to compare individual performance against a standard. In order to facilitate 3D reconstruction and objective analysis and thus provide more accurate quantitation results when analyzing specimens, it is essential to automatically identify the capsule line that separates the prostate gland tissue …

Adaptive Interpolation Algorithms For Temporal-Oriented Datasets, Jun Gao

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Spatiotemporal datasets can be classified into two categories: temporal-oriented and spatial-oriented datasets depending on whether missing spatiotemporal values are closer to the values of its temporal or spatial neighbors. We present an adaptive spatiotemporal interpolation model that can estimate the missing values in both categories of spatiotemporal datasets. The key parameters of the adaptive spatiotemporal interpolation model can be adjusted based on experience.

A Multilane Pipelined Architecture For Real Time Enhancement Of Color Video Streams, Adam Redd Livingston

Electrical & Computer Engineering Theses & Dissertations

Video stream enhancement is a key fixture in a wide variety of applications from video surveillance, automatic navigation, medical imagery, to facial/object recognition systems. When a video stream contains non-uniform lighting it can be difficult to obtain what is in the darker regions without over enhancing brighter regions. The Adaptive and Integrated Neighborhood Dependant Approach for Nonlinear Enhancement (AINDANE) algorithm combines a tunable nonlinear transfer function, convolution by a multi-scale Gaussian kernel, and tunable contrast enhancement to address this problem for a single image. Luminance values are tuned based on the global cumulative distribution function (CDF) of an image. Contrast …

A Non-Linear Technique For The Enhancement Of Extremely Non-Uniform Lighting Images, Ender Oguslu

Electrical & Computer Engineering Theses & Dissertations

At night scenes, either the low intensity areas that are under poor light or the high intensity areas that are overexposed cannot be clearly seen. Various image processing techniques have been developed to recover the meaningful information under extremely low lighting conditions. Among these, the algorithms based on integrated neighborhood dependency of pixel characteristics and based on the illuminance reflectance model perform well for improving the visual quality of digital images captured under nonuniform and extremely low lighting conditions. Although these techniques perform well in low lighting conditions, they cannot perform well in overexposed regions under dark environments such as …

Reversing Ticket Based Probing (Rtbp) Routing For Manet, Turgut Yucel

Electrical & Computer Engineering Theses & Dissertations

The delay-constrained maximum-bandwidth routing problem in MANET (Mobile Ad hoc Networks) is to find the maximum bandwidth path which satisfies a given delay constraint. The research challenge for this problem is that the networking information used for routing may be imprecise. The Ticket-Based Probing (TBP) routing algorithm provides a heuristic approach by using two types of ticket. In this thesis a Reversing Ticket-based Probing (RTBP) routing algorithm is proposed. The RTBP has two novel features compared to the original ticket based probing algorithms. The first feature is using just one type ticket, instead of two types of ticket. RTBP generates …

Mobius: An Omnidirectional Robotic Platform And Software Architecture For Network Teleoperation, Samuel Aaron Miller

Electrical & Computer Engineering Theses & Dissertations

The following thesis presents the results of a project to develop and test an omnidirectional robotic system (hardware and software) at NASA Langley Research Center's Robotics and Intelligent Machines Lab. The impetus for the project was the unique capabilities of omnidirectional systems. Some of the many potential benefits these systems have include improved material-handling capabilities in constrained environments (such as might be found in extraterrestrial manned habitats), efficient camera-based vehicle teleoperation, and simplified route planning for autonomous robot operations.

The project's focus was to design, build, and test a system that used Mecanum wheels to achieve omnidirectional motion. In addition …

The Reliability Of The Computer Communication Networks Including Mobile Nodes, Sahin Yasar

Electrical & Computer Engineering Theses & Dissertations

The wireless computer networks have an uncertainty in their structures aside from their big advantages for the users. The environmental conditions, changing locations of the mobile hosts and the changing components in the system can easily affect their reliability. In order to know a system capability performing its functions, keep the reliability at a certain level and/or detect the deficiency of the system, it is necessary to analyze the reliability of a computer communication network including the wired and wireless parts. But the above reasons also make the analysis and a unique solution difficult so a set of algorithms is …

Verification Of A Decision Level Fusion Algorithm Using A Proven Atr System And Measured Sar Data, James Douglas Thompson

Theses and Dissertations

Decision level fusion (DLF) algorithms combine outputs of multiple single sensors to make one confident declaration of a target. This research compares performance results of a DLF algorithm using measured data and a proven ATR system with results from simulated data and a modeled ATR system. This comparison indicates that DLF offers significant performance improvements over single sensor looks. However, results based on simulated data and a modeled ATR are slightly optimistic and overestimate results from measured data and a proven ATR system by nearly 10% over all targets tested.

Multiframe Shift Estimation, Stephen A. Bruckart

Theses and Dissertations

The purpose of this research was to develop a fundamental framework for a new approach to multiframe translational shift estimation in image processing. This thesis sought to create a new multiframe shift estimator, to theoretically prove and experimentally test key properties of it, and to quantify its performance according to several metrics. The new estimator was modeled successfully and was proven to be an unbiased estimator under certain common image noise conditions. Furthermore its performance was shown to be superior to the cross correlation shift estimator, a robust estimator widely used in similar image processing cases, according to several criteria. …

Efficient Scheduling For Sdmg Cioq Switches, Mei Yang, S. Q. Zheng

Electrical & Computer Engineering Faculty Research

Combined input and output queuing (CIOQ) switches are being considered as high-performance switch architectures due to their ability to achieve 100% throughput and perfectly emulate output queuing (OQ) switch performance with a small speedup factor S. To realize a speedup factor S, a conventional CIOQ switch requires the switching fabric and memories to operate S times faster than the line rate. In this paper, we propose to use a CIOQ switch with space-division multiplexing expansion and grouped input/output ports (SDMG CIOQ switch for short) to realize speedup while only requiring the switching fabric and memories to operate at the line …

A Tabu Search Algorithm To Minimize The Makespan For The Unrelated Parallel Machines Scheduling Problem With Setup Times, Magdy Helal, Ghaith Rabadi, Ameer Al-Salem

Engineering Management & Systems Engineering Faculty Publications

In this paper we propose a tabu search implementation to solve the unrelated parallel machines scheduling problem with sequence- and machine- dependent setup times to minimize the schedules makespan. The problem is NP-hard and finding an optimal solution efficiently is unlikely. Therefore, heuristic techniques are more appropriate to find near-optimal solutions. The proposed tabu search algorithm uses two phases of perturbation schemes: the intra-machine perturbation, which optimizes the sequence of jobs on the machines, and the inter-machine perturbation, which balances the assignment of the jobs to the machines. We compare the proposed algorithm to an existing one that addressed the …

Hybrid Committee Classifier For A Computerized Colonic Polyp Detection System, Jiang Li, Jianhua Yao, Nicholas Petrick, Ronald M. Summers, Amy K. Hara, Joseph M. Reinhardt (Ed.), Josien P.W. Pluim (Ed.)

Electrical & Computer Engineering Faculty Publications

We present a hybrid committee classifier for computer-aided detection (CAD) of colonic polyps in CT colonography (CTC). The classifier involved an ensemble of support vector machines (SVM) and neural networks (NN) for classification, a progressive search algorithm for selecting a set of features used by the SVMs and a floating search algorithm for selecting features used by the NNs. A total of 102 quantitative features were calculated for each polyp candidate found by a prototype CAD system. 3 features were selected for each of 7 SVM classifiers which were then combined to form a committee of SVMs classifier. Similarly, features …

Robust And Efficient Localization Techniques For Cellular And Wireless Sensor Networks, Haseebulla M. Khan

Computer Science Theses & Dissertations

Localization in wireless networks refers to a collection of tasks that, collectively, determines the location of a mobile user, striving to hide the effects of mobility from the user and/or application. Localization has become an important issue and has drawn considerable attention, as many applications including E-911, cargo tracking, locating patients, location-sensitive billing, etc., require knowledge of the location of user/objects. It was realized, quite a while back, that extending emergency 911-like services (E-911) to continually growing mobile population is one of the extremely important localization applications. The bulk of the proposed solutions to emergency location management in wireless environments …

Mobility-Pattern Based Localization Update Algorithm For Mobile Wireless Sensor Networks, Mohammad Yacoub Al-Laho

Electrical & Computer Engineering Theses & Dissertations

In mobile wireless sensor networks, sensors move in the monitored area at any direction and speed. Unlike many other networking hosts, sensor nodes do not have global addresses. They are often identified by using a location-based addressing scheme. Therefore, it is important to have the knowledge of the sensor location indicating where the data came from. In this thesis, three localization update algorithms were designed, Specifically, a sensor movement is divided into three states: Pause, Linear, and Random. Each state adopts different localization update algorithm. Since complex movement involves different mobility patterns, a state transition model is developed to …

Determination Of Structure From Motion Using Aerial Imagery, Paul R. Graham

Theses and Dissertations

The structure from motion process creates three-dimensional models from a sequence of images. Until recently, most research in this field has been restricted to land-based imagery. This research examines the current methods of land-based structure from motion and evaluates their performance for aerial imagery. Current structure from motion algorithms search the initial image for features to track though the subsequent images. These features are used to create point correspondences between the two images. The correspondences are used to estimate the motion of the camera and then the three-dimensional structure of the scene. This research tests current algorithms using synthetic data …

Introduction: Data Communication And Topology Algorithms For Sensor Networks, Stephan Olariu, David Simplot-Ryl, Ivan Stojmenovic

Computer Science Faculty Publications

(First paragraph) We are very proud and honored to have been entrusted to be Guest Editors for this special issue. Papers were sought to comprehensively cover the algorithmic issues in the “hot” area of sensor networking. The concentration was on network layer problems, which can be divided into two groups: data communication problems and topology control problems. We wish to briefly introduce the five papers appearing in this special issue. They cover specific problems such as time division for reduced collision, fault tolerant clustering, self-stabilizing graph optimization algorithms, key pre-distribution for secure communication, and distributed storage based on spanning trees …

Vector Operations In Superscalar Architectures, Nathan Daniel Flinn

Electrical & Computer Engineering Theses & Dissertations

Vector calculations are very prevalent today. Though the vector-processing computer is quite an old concept, superscalar processors lack hardware support for vector operations. This thesis investigates whether an ordinary superscalar computer architecture can be designed to include hardware support for improved vector operations without drastically changing the existing superscalar design and behavior. A computer architecture design was created and implemented that included the vector multiply (dot product) operation. The design includes a Vector Operations Unit that captures incoming vector operations and generates the necessary set of machine instructions to complete the vector operation internally. It then delivers these instructions to …

Hierarchical Hybrid Multicast An End System Multicast Algorithm Approach, Guillermo Loaisiga

Electrical & Computer Engineering Theses & Dissertations

Due to the rapid development in the computer and communication technologies, the Internet is experiencing an increasing demand of high-speed, real-time distributed applications, such as live streaming multimedia, videoconferencing, distributed simulations, and multiparty games. Multicast is an efficient transmission mechanism to support these applications. Historically, IP Multicast (IPM) has provided multicast support with well-known benefits, especially in bandwidth savings. However, it has experienced little deployment due to economic and architectural limitations.

Overlay multicast holds promise for the implementation of large scale Internet multicast services. An overlay network is a virtual topology constructed on top of the Internet infrastructure. This concept …

A Fast And Simple Algorithm For Computing M Shortest Paths In Stage Graph, M. Sherwood, Laxmi P. Gewali, Henry Selvaraj, Venkatesan Muthukumar

Electrical & Computer Engineering Faculty Research

We consider the problem of computing m shortest paths between a source node s and a target node t in a stage graph. Polynomial time algorithms known to solve this problem use complicated data structures. This paper proposes a very simple algorithm for computing all m shortest paths in a stage graph efficiently. The proposed algorithm does not use any complicated data structure and can be implemented in a straightforward way by using only array data structure. This problem appears as a sub-problem for planning risk reduced multiple k-legged trajectories for aerial vehicles.

A Fast And Simple Algorithm For Computing M-Shortest Paths In State Graph, M. Sherwood, Laxmi P. Gewali, Henry Selvaraj, Venkatesan Muthukumar

Electrical & Computer Engineering Faculty Research

We consider the problem of computing m shortest paths between a source node s and a target node t in a stage graph. Polynomial time algorithms known to solve this problem use complicated data structures. This paper proposes a very simple algorithm for computing all m shortest paths in a stage graph efficiently. The proposed algorithm does not use any complicated data structure and can be implemented in a straightforward way by using only array data structure. This problem appears as a sub-problem for planning risk reduced multiple k-legged trajectories for aerial vehicles.

Qos Routing Optimization Strategy Using Genetic Algorithm In Optical Fiber Communication Networks, Zhaoxia Wang, Zengqiang Chen, Zhuzhi Yuan

Research Collection School Of Computing and Information Systems

This paper describes the routing problems in optical fiber networks, defines five constraints, induces and simplifies the evaluation function and fitness function, and proposes a routing approach based on the genetic algorithm, which includes an operator [OMO] to solve the QoS routing problem in optical fiber communication networks. The simulation results show that the proposed routing method by using this optimal maintain operator genetic algorithm (OMOGA) is superior to the common genetic algorithms (CGA). It not only is robust and efficient but also converges quickly and can be carried out simply, that makes it better than other complicated GA.

Unidirectional Cordic For Efficient Computation Of Trigonometric And Hyperbolic Functions, Satish Ravichandran

Electrical & Computer Engineering Theses & Dissertations

CORDIC (Coordinate Rotation Digital Computer) is an iterative algorithm to compute values of trigonometric, logarithmic and transcendental functions by performing vector rotations, which can be implemented with only shift and add operations in a digital system. CORDIC algorithms are extensively used in the areas of digital signal processing, digital image processing and artificial neural networks. A new technique, named unidirectional CORDIC, for efficient computation of trigonometric and hyperbolic functions is presented in this thesis. In the conventional CORDIC algorithm, the vector rotations are performed in both clockwise and counterclockwise directions, but in the unidirectional CORDIC the vectors are rotated only …

Automatic Speaker Identification Using Reusable And Retrainable Binary-Pair Partitioned Neural Networks, Ashutosh Mishra

Electrical & Computer Engineering Theses & Dissertations

This thesis presents an extension of the work previously done on speaker identification using Binary Pair Partitioned (BPP) neural networks. In the previous work, a separate network was used for each pair of speakers in the speaker population. Although the basic BPP approach did perform well and had a simple underlying algorithm, it had the obvious disadvantage of requiring an extremely large number of networks for speaker identification with large speaker populations. It also requires training of networks proportional to the square of the number of speakers under consideration, leading to a very large number of networks to be trained …

Interpolation Techniques For Overset Grids, Paul S. Sherman, Nathan B. Edgar

Journal of the Arkansas Academy of Science

The use of finite difference schemes in computational aeroacoustics requires the use of structured grids incomputational space. Complex geometries in the physical space can be modeled using multiple overlapping grids that are transformed into computational space. In this work, finite difference schemes are used that necessitate the addition of psuedo- or ghost-points in the overlap region of the grids for closure of the difference stencil. The functional values at these ghost points must be approximated from the values at the original grid points. This paper investigates interpolation techniques for these overset grids. An n th order interpolation scheme using Lagrange …

Study Of Transport Properties Of Inas Using Monte Carlo Simulation, Satyanadh Gundimada

Electrical & Computer Engineering Theses & Dissertations

The present research is aimed at ascertaining the usefulness of InAs semiconductor material for single photon avalanche photo detectors operating in the Geiger mode at 2 μm wavelengths. InAs is considered as the material suitable for the purpose because of its less bandgap and lower effective mass of the electrons when compared to other semiconductor materials presently in use. Hence, theoretically transient transport properties of bulk InAs are superior and the velocity overshoot phenomena stronger. InAs is a relatively less explored material when compared to other materials like GaAs. The choice of the material is justified with thorough exploration of …

Yet Another Algorithm For Pitch Tracking (Yaapt), Kavita Kasi

Electrical & Computer Engineering Theses & Dissertations

This thesis presents a pitch detection algorithm that is extremely robust for both high quality and telephone speech. The kernel method for this algorithm is the Normalized Cross Correlation (NCCF) reported by David Talkin [16]. Major innovations include: processing of the original acoustic signal and a nonlinearly processed version of the signal to partially restore very weak F0 components; intelligent peak picking to select multiple F0 candidates and assign merit factors; and, incorporation of highly robust pitch contours obtained from smoothed versions of low frequency portions of spectrograms. Dynamic programming is used to find the ''best" pitch track among all …

On The Area Of Hypercube Layouts, Ronald I. Greenberg, Lee Guan

Computer Science: Faculty Publications and Other Works

This paper precisely analyzes the wire density and required area in standard styles for the hypercube. It shows that the most natural, regular layout of a hypercube of N^2 nodes in the plane, in a NxN grid arrangement, uses floor(2N/3)+1 horizontal wiring tracks for each row of nodes. (In the process, we see that the number of tracks per row can be reduced by 1 with a less regular design, as can also be seen from an independent argument of Bezrukov et al.) This paper also gives a simple formula for the wire density at any cut position and a …