Physical Sciences and Mathematics Commons^™

Measures Of Centrality Based On The Spectrum Of The Laplacian, Scott D. Pauls, Daniel Remondini

Dartmouth Scholarship

We introduce a family of new centralities, the k-spectral centralities. k-Spectral centrality is a measurement of importance with respect to the deformation of the graph Laplacian associated with the graph. Due to this connection, k-spectral centralities have various interpretations in terms of spectrally determined information.

We explore this centrality in the context of several examples. While for sparse unweighted net- works 1-spectral centrality behaves similarly to other standard centralities, for dense weighted net- works they show different properties. In summary, the k-spectral centralities provide a novel and useful measurement of relevance (for single network elements as well as whole subnetworks) …

A Survey On Bio-Inspired Algorithms For Web Service Composition, Lijuan Wang, Jun Shen, Jianming Yong

Dr Jun Shen

Web service composition has become a promis- ing technology in a variety of e-science or e-business areas. There are a variety of models and methods to deal with this issue from di#11;erent aspects. Bio-inspired algorithms are becoming main approaches and solutions. This paper reviews the current researches on web service composition based on bio-inspired algorithms, such as Ant Colony Opti- mization(ACO), Genetic Algorithm(GA), Evolutionary Al- gorithm(EA) and Particle Swarm Optimization(PSO). By analyzing and investigating di#11;erent approaches, this paper gives an overview about the researches on bio-inspired al- gorithm in web service composition and point out future directions.

Validation Of Weak Form Thermal Analysis Algorithms Supporting Thermal Signature Generation, Elton Lewis Freeman

Masters Theses

Extremization of a weak form for the continuum energy conservation principle differential equation naturally implements fluid convection and radiation as flux Robin boundary conditions associated with unsteady heat transfer. Combining a spatial semi-discretization via finite element trial space basis functions with time-accurate integration generates a totally node-based algebraic statement for computing. Closure for gray body radiation is a newly derived node-based radiosity formulation generating piecewise discontinuous solutions, while that for natural-forced-mixed convection heat transfer is extracted from the literature. Algorithm performance, mathematically predicted by asymptotic convergence theory, is subsequently validated with data obtained in 24 hour diurnal field experiments for …

Enhancing Effective Depth-Of-Field By Multi-Focus Image Fusion Using Morphological Techniques., Ishita De Ghosh Dr.

Doctoral Theses

A scene to be photographed, usually includes objects at varying distances from the camera. Depth-of-field of a digital camera is the range of distance, all objects within which appear to be sharp in the image. Due to the low depth-of-field of the camera, images acquired by them often suffer from degradation called out-of-foc us blur. One way to enhance the effective depth-of-field is to acquire se veral images of a scene with focus on different parts of it and then combine these images into a single image in such a way that all regions of the scene are in focus. …

Blackbox Reduction Of Some Cryptographic Constructions., Rishiraj Bhattacharyya Dr.

Doctoral Theses

No abstract provided.

On The Computational Complexity Of The Lbg And Pnn Algorithms, Jamshid Shanbehzadeh, Philip Ogunbona

Professor Philip Ogunbona

This correspondence compares the computational complexity of the pair-wise nearest neighbor (PNN) and Linde–Buzo–Gray (LBG) algorithms by deriving analytical expressions for their computational times. It is shown that for a practical codebook size and training vector sequence, the LBG algorithm is indeed more computationally efficient than the PNN algorithm.

Adapting Video Delivery Based On Motion Triggered Visual Attention, Hari Kalva, V. Adzic, Lai-Tee Cheok

Research Collection School Of Computing and Information Systems

Cues from human visual system (HVS) can be used for further optimization of compression in modern hybrid video coding platforms. We present work that explores and exploits motion related attentional limitations. Algorithms for exploiting motion triggered attention were developed and compared with MPEG AVC/H.264 encoder with various settings for different bitrate levels. For the sequences with high motion activity our algorithm provides up to 8% bitrate savings.

Genetic Association Studies Of Copy-Number Variation: Should Assignment Of Copy Number States Precede Testing?, Patrick Breheny, Prabhakar Chalise, Anthony Batzler, Liewei Wang, Brooke L. Fridley

Biostatistics Faculty Publications

Recently, structural variation in the genome has been implicated in many complex diseases. Using genomewide single nucleotide polymorphism (SNP) arrays, researchers are able to investigate the impact not only of SNP variation, but also of copy-number variants (CNVs) on the phenotype. The most common analytic approach involves estimating, at the level of the individual genome, the underlying number of copies present at each location. Once this is completed, tests are performed to determine the association between copy number state and phenotype. An alternative approach is to carry out association testing first, between phenotype and raw intensities from the SNP array …

Determining Angular Frequency From A Video With A Generalized Fast Fourier Transform, Lindsay N. Smith

Theses and Dissertations

Suppose we are given a video of a rotating object and suppose we want to determine the rate of rotation solely from the video itself and its known frame rate. In this thesis, we present a new mathematical operator called the Geometric Sum Transform (GST) that can help one determine the angular frequency of the object in question. The GST is a generalization of the discrete Fourier transform (DFT) and as such, the two transforms have much in common. However, whereas the DFT is applied to a sequence of scalars, the GST can be applied to a sequence of vectors. …

Some Results On Cryptanalysis Of Rsa And Factorization., Santanu Sarkar Dr.

Doctoral Theses

In this thesis, we propose some new results in Cryptanalysis of RSA and related Factorization problems. Till date, the best known algorithm to solve the Integer Factorization problem is the Number Field Sieve, which has a runtime greater than exp(log1/3 N) for factoring an integer N. However, if one obtains certain information about the RSA parameters, there are algorithms which can factor the RSA modulus N = pq quite efficiently. The intention of this thesis is to identify such weaknesses of the RSA cryptosystem and its variants. Further we study results related to factorization.In Africacrypt 2008, Nitaj presented a class …

Convergence Analysis Of A Multigrid Algorithm For The Acoustic Single Layer Equation, Simon Gemmrich, Jay Gopalakrishnan, Nilima Nigam

Mathematics and Statistics Faculty Publications and Presentations

We present and analyze a multigrid algorithm for the acoustic single layer equation in two dimensions. The boundary element formulation of the equation is based on piecewise constant test functions and we make use of a weak inner product in the multigrid scheme as proposed in Bramble et al. (1994) . A full error analysis of the algorithm is presented. We also conduct a numerical study of the effect of the weak inner product on the oscillatory behavior of the eigenfunctions for the Laplace single layer operator.

Positive Semidefinite Metric Learning Using Boosting-Like Algorithms, Chunhua Shen, Junae Kim, Lei Wang, Anton Van Den Hengel

Faculty of Informatics - Papers (Archive)

The success of many machine learning and pattern recognition methods relies heavily upon the identification of an appropriate distance metric on the input data. It is often beneficial to learn such a metric from the input training data, instead of using a default one such as the Euclidean distance. In this work, we propose a boosting-based technique, termed BOOSTMETRIC, for learning a quadratic Mahalanobis distance metric. Learning a valid Mahalanobis distance metric requires enforcing the constraint that the matrix parameter to the metric remains positive semidefinite. Semidefinite programming is often used to enforce this constraint, but does not scale well …

Methane Retrievals From Greenhouse Gases Observing Satellite (Gosat) Shortwave Infrared Measurements: Performance Comparison Of Proxy And Physics Retrieval Algorithms, D Schepers, S Guerlet, A Butz, J Landgraf, C Frankenberg, O Hasekamp, J-F Blavier, N M. Deutscher, D W. T Griffith, F Hase, E Kyro, I Morino, V Sherlock, R Sussmann, I Aben

Faculty of Science - Papers (Archive)

We compare two conceptually different methods for determining methane column-averaged mixing ratios (X_CH4) from Greenhouse Gases Observing Satellite (GOSAT) shortwave infrared (SWIR) measurements. These methods account differently for light scattering by aerosol and cirrus. The proxy method retrieves a CO₂ column which, in conjunction with prior knowledge on CO₂ acts as a proxy for scattering effects. The physics-based method accounts for scattering by retrieving three effective parameters of a scattering layer. Both retrievals are validated on a 19-month data set using ground-based X_CH4 measurements at 12 stations of the Total Carbon Column Observing Network (TCCON), …

Fast Software Multiplication In F_2[X] For Embedded Processors, Serdar Süer Erdem

Turkish Journal of Electrical Engineering and Computer Sciences

We present a novel method for fast multiplication of polynomials over F_2 which can be implemented efficiently in embedded software. Fast polynomial multiplication methods are needed for the efficient implementation of some cryptographic and coding applications. The proposed method follows a strategy to reduce the memory accesses for input data and intermediate values during computation. This strategy speeds up the binary polynomial multiplication significantly on typical embedded processors with limited memory bandwidth. These multiplications are usually performed by the comb method or the Karatsuba-based methods in embedded software. The proposed method has speed and memory advantages over these methods on …

On The Hardness Of Counting And Sampling Center Strings, Christina Boucher, Mohamed Omar

All HMC Faculty Publications and Research

Given a set S of n strings, each of length ℓ, and a nonnegative value d, we define a center string as a string of length ` that has Hamming distance at most d from each string in S. The #CLOSEST STRING problem aims to determine the number of center strings for a given set of strings S and input parameters n, ℓ, and d. We show #CLOSEST STRING is impossible to solve exactly or even approximately in polynomial time, and that restricting #CLOSEST STRING so that any one of the parameters n, ℓ, or d is fixed leads to …

Algorithms For Community Identification In Complex Networks, Mahadevan Vasudevan

Electronic Theses and Dissertations

First and foremost, I would like to extend my deepest gratitude to my advisor, Professor Narsingh Deo, for his excellent guidance and encouragement, and also for introducing me to this wonderful science of complex networks. Without his support this dissertation would not have been possible. I would also like to thank the members of my research committee, professors Charles Hughes, Ratan Guha, Mainak Chatterjee and Yue Zhao for their advice and guidance during the entire process. I am indebted to the faculty and the staff of the Department of Electrical Engineering and Computer Science for providing me the resources and …

Using Monte Carlo Tree Search For Replanning In A Multistage Simultaneous Game, Daniel Beard, Philip Hingston, Martin Masek

Research outputs 2012

In this study, we introduce MC-TSAR, a Monte Carlo Tree Search algorithm for strategy selection in simultaneous multistage games. We evaluate the algorithm using a battle planning scenario in which replanning is possible. We show that the algorithm can be used to select a strategy that approximates a Nash equilibrium strategy, taking into account the possibility of switching strategies part way through the execution of the scenario in the light of new information on the progress of the battle.

A Survey On Bio-Inspired Algorithms For Web Service Composition, Lijuan Wang, Jun Shen, Jianming Yong

Faculty of Informatics - Papers (Archive)

Web service composition has become a promis- ing technology in a variety of e-science or e-business areas. There are a variety of models and methods to deal with this issue from dierent aspects. Bio-inspired algorithms are becoming main approaches and solutions. This paper reviews the current researches on web service composition based on bio-inspired algorithms, such as Ant Colony Opti- mization(ACO), Genetic Algorithm(GA), Evolutionary Al- gorithm(EA) and Particle Swarm Optimization(PSO). By analyzing and investigating dierent approaches, this paper gives an overview about the researches on bio-inspired al- gorithm in web service composition and point out future directions.

Equational Unification : Algorithms And Complexity With Applications To Cryptographic Protocol Analysis, Andrew Marshall

Legacy Theses & Dissertations (2009 - 2024)

The techniques and tools of unification theory have long been a core component of many

Toward Automatic Subpixel Registration Of Unmanned Airborne Vehicle Images, Amr Hussein Yousef, Jiang Li, Mohammad Karim, Mark Allen Neifeld (Ed.), Amit Ashok (Ed.)

Electrical & Computer Engineering Faculty Publications

Many applications require to register images within subpixel accuracy like computer vision especially super-resolution (SR) where the estimated subpixel shifts are very crucial in the reconstruction and restoration of SR images. In our work we have an optical sensor that is mounted on an unmanned airborne vehicle (UAV) and captures a set of images that contain sufficient overlapped area required to reconstruct a SR image. Due to the wind, The UAV may encounter rotational effects such as yaw, pitch and roll which can distort the acquired as well as processed images with shear, tilt or perspective distortions. In this paper …

Fusion Of Visual And Thermal Images Using Genetic Algorithms, Sertan Erkanli, Jiang Li, Ender Oguslu, Shangce Gao (Ed.)

Electrical & Computer Engineering Faculty Publications

No abstract provided.