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Theory and Algorithms

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Articles 1891 - 1920 of 2151

Full-Text Articles in Computer Sciences

Intelligent System Applications Based On Genetic Algorithms, Yasin Volkan Pehlivanoglu Apr 2006

Intelligent System Applications Based On Genetic Algorithms, Yasin Volkan Pehlivanoglu

Mechanical & Aerospace Engineering Theses & Dissertations

As a stochastic search method, evolutionary algorithm (EA) is an emergent optimization algorithm mimicking the natural evolution, where a "biological population" evolves over generations to adapt to an environment by selection, recombination, and mutation. When EA is applied to optimization problems, fitness, individual, and genes usually correspond to an objective function value, a design candidate, and design variables, respectively.

One of the key features of EA is that they search from multiple points in design space, instead of moving from a single point as in gradient-based methods. Furthermore, EA works on function evaluations alone and does not require derivatives or …


The Reliability Of The Computer Communication Networks Including Mobile Nodes, Sahin Yasar Apr 2006

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 …


A Unified Log-Based Relevance Feedback Scheme For Image Retrieval, Steven Hoi, Michael R. Lyu, Rong Jin Apr 2006

A Unified Log-Based Relevance Feedback Scheme For Image Retrieval, Steven Hoi, Michael R. Lyu, Rong Jin

Research Collection School Of Computing and Information Systems

Relevance feedback has emerged as a powerful tool to boost the retrieval performance in content-based image retrieval (CBIR). In the past, most research efforts in this field have focused on designing effective algorithms for traditional relevance feedback. Given that a CBIR system can collect and store users' relevance feedback information in a history log, an image retrieval system should be able to take advantage of the log data of users' feedback to enhance its retrieval performance. In this paper, we propose a unified framework for log-based relevance feedback that integrates the log of feedback data into the traditional relevance feedback …


Type Ii Quantum Computing Algorithm For Computational Fluid Dynamics, James A. Scoville Mar 2006

Type Ii Quantum Computing Algorithm For Computational Fluid Dynamics, James A. Scoville

Theses and Dissertations

An algorithm is presented to simulate fluid dynamics on a three qubit type II quantum computer: a lattice of small quantum computers that communicate classical information. The algorithm presented is called a three qubit factorized quantum lattice gas algorithm. It is modeled after classical lattice gas algorithms which move virtual particles along an imaginary lattice and change the particles’ momentums using collision rules when they meet at a lattice node. Instead of moving particles, the quantum algorithm presented here moves probabilities, which interact via a unitary collision operator. Probabilities are determined using ensemble measurement and are moved with classical communications …


Multiframe Shift Estimation, Stephen A. Bruckart Mar 2006

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. …


An Estimation Theory Approach To Detection And Ranging Of Obscured Targets In 3-D Ladar Data, Charles R. Burris Mar 2006

An Estimation Theory Approach To Detection And Ranging Of Obscured Targets In 3-D Ladar Data, Charles R. Burris

Theses and Dissertations

The purpose of this research is to develop an algorithm to detect obscured images in 3-D LADAR data. The real data used for this research was gathered using a FLASH LADAR system under development at AFRL/SNJM. The system transmits light with a wavelength of 1.55 micrometers and produces 20 128 X 128 temporally resolved images from the return pulse separated by less than 2 nanoseconds in time. New algorithms for estimating the range to a target in 3-D FLASH LADAR data were developed. Results from processing real data are presented and compared to the traditional correlation receiver for extracting ranges …


Verification Of A Decision Level Fusion Algorithm Using A Proven Atr System And Measured Sar Data, James Douglas Thompson Mar 2006

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.


A Hybrid Scatter Search/Electromagnetism Meta-Heuristic For Project Scheduling, Dieter Debels, Bert De Reyck, Roel Leus, Mario Vanhoucke Mar 2006

A Hybrid Scatter Search/Electromagnetism Meta-Heuristic For Project Scheduling, Dieter Debels, Bert De Reyck, Roel Leus, Mario Vanhoucke

Research Collection Lee Kong Chian School Of Business

In the last few decades, several effective algorithms for solving the resource-constrained project scheduling problem have been proposed. However, the challenging nature of this problem, summarised in its strongly NP-hard status, restricts the effectiveness of exact optimisation to relatively small instances. In this paper, we present a new meta-heuristic for this problem, able to provide near-optimal heuristic solutions for relatively large instances. The procedure combines elements from scatter search, a generic population-based evolutionary search method, and from a recently introduced heuristic method for the optimisation of unconstrained continuous functions based on an analogy with electromagnetism theory. We present computational …


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 Jan 2006

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 …


Fast Bounds On The Distribution Of Smooth Numbers, Scott T. Parsell, Jonathan P. Sorenson Jan 2006

Fast Bounds On The Distribution Of Smooth Numbers, Scott T. Parsell, Jonathan P. Sorenson

Scholarship and Professional Work - LAS

In this paper we present improvements to Bernstein’s algorithm, which finds rigorous upper and lower bounds for (x, y).


The Pseudosquares Prime Sieve, Jonathan P. Sorenson Jan 2006

The Pseudosquares Prime Sieve, Jonathan P. Sorenson

Scholarship and Professional Work - LAS

We present the pseudosquares prime sieve, which finds all primes up to n.


Realtime Query Expansion And Procedural Interfaces For Information Hierarchies, Saverio Perugini Jan 2006

Realtime Query Expansion And Procedural Interfaces For Information Hierarchies, Saverio Perugini

Computer Science Faculty Publications

We demonstrate the use of two user interfaces for interacting with web hierarchies. One uses the dependencies underlying a hierarchy to perform real-time query expansion and, in this way, acts as an in situ feedback mechanism. The other enables the user to cascade the output from one interaction to the input of another, and so on, and, in this way, supports procedural information-seeking tasks without disrupting the flow of interaction.


Information Assurance Through Binary Vulnerability Auditing, William B. Kimball, Saverio Perugini Jan 2006

Information Assurance Through Binary Vulnerability Auditing, William B. Kimball, Saverio Perugini

Computer Science Faculty Publications

The goal of this research is to develop improved methods of discovering vulnerabilities in software. A large volume of software, from the most frequently used programs on a desktop computer, such as web browsers, e-mail programs, and word processing applications, to mission-critical services for the space shuttle, is unintentionally vulnerable to attacks and thus insecure. By seeking to improve the identification of vulnerabilities in software, the security community can save the time and money necessary to restore compromised computer systems. In addition, this research is imperative to activities of national security such as counterterrorism. The current approach involves a systematic …


Unsymmetrical And Symmetrical Sparse Iterative Algorithm With Multiple Right-Hand-Sides Strategies, D. T. Nguyen, A. P. Honrao, G. Hou, O. Akan, O. Baysal Jan 2006

Unsymmetrical And Symmetrical Sparse Iterative Algorithm With Multiple Right-Hand-Sides Strategies, D. T. Nguyen, A. P. Honrao, G. Hou, O. Akan, O. Baysal

Civil & Environmental Engineering Faculty Publications

Unified unsymmetrical and symmetrical iterative solvers for handling multiple right-hand-side vectors are examined in this work. Efficient computer implementation strategies (to reduce computational time and in-core memory requirements) are proposed. In-core, out-of-core, linear, multiple right hand side (RHS) vectors, non-linear, symmetrical, and unsymmetrical capabilities of the developed software are demonstrated by solving variety of problems selected form different engineering disciplines. Results indicate that the developed algorithm and software is reliable and efficient.


Classical And Quantum Algorithms For Finding Cycles, Jill Cirasella Jan 2006

Classical And Quantum Algorithms For Finding Cycles, Jill Cirasella

Publications and Research

Quantum computing—so weird, so wonderful—inspires much speculation about the line between the possible and the impossible. (Of course, there is still unclarity about how “impossible” intractable problems are and about how “possible” quantum computers are.) This thesis takes a slightly different tack: instead of focusing on how to make the impossible possible, it focuses on how to make the possible easier.

More specifically, this paper discusses quantum algorithms for finding cycles in graphs, a problem for which polynomial-time classical algorithms already exist. It explains and compares the classical and quantum algorithms, and it introduces a few new algorithms and observations. …


Efficient Scheduling For Sdmg Cioq Switches, Mei Yang, S. Q. Zheng Jan 2006

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 …


Handling The Subclassing Anomaly With Object Teams, Jeff Furlong, Atanas Radenski Jan 2006

Handling The Subclassing Anomaly With Object Teams, Jeff Furlong, Atanas Radenski

Mathematics, Physics, and Computer Science Faculty Articles and Research

Existing Java software or libraries can evolve via subclassing. Unfortunately, subclassing may not properly support code adaptation when there are dependencies between classes. More precisely, subclassing in collections of related classes may require reimplementation of otherwise valid classes. This problem is defined as the subclassing anomaly, which is an issue when software evolution or code reuse is a goal of the programmer who is using existing classes. Object Teams offers an implicit fix to this problem and is largely compatible with the existing JVM’s. In this paper, we evaluate how well Object Teams succeeds in providing a solution for a …


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.) Jan 2006

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 …


Group Key Management In Wireless Ad-Hoc And Sensor Networks, Mohammed A. Moharrum Jan 2006

Group Key Management In Wireless Ad-Hoc And Sensor Networks, Mohammed A. Moharrum

Computer Science Theses & Dissertations

A growing number of secure group applications in both civilian and military domains is being deployed in WAHNs. A Wireless Ad-hoc Network (WARN) is a collection of autonomous nodes or terminals that communicate with each other by forming a multi-hop radio network and maintaining connectivity in a decentralized manner. A Mobile Ad-hoc Network (MANET) is a special type of WARN with mobile users. MANET nodes have limited communication, computational capabilities, and power. Wireless Sensor Networks (WSNs) are sensor networks with massive numbers of small, inexpensive devices pervasive throughout electrical and mechanical systems and ubiquitous throughout the environment that monitor and …


Robust And Efficient Localization Techniques For Cellular And Wireless Sensor Networks, Haseebulla M. Khan Dec 2005

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 …


On Static And Dynamic Partitioning Behavior Of Large-Scale Networks, Derek Leonard, Zhongmei Yao, Xiaoming Wang, Dmitri Loguinov Nov 2005

On Static And Dynamic Partitioning Behavior Of Large-Scale Networks, Derek Leonard, Zhongmei Yao, Xiaoming Wang, Dmitri Loguinov

Computer Science Faculty Publications

In this paper, we analyze the problem of network disconnection in the context of large-scale P2P networks and understand how both static and dynamic patterns of node failure affect the resilience of such graphs. We start by applying classical results from random graph theory to show that a large variety of deterministic and random P2P graphs almost surely (i.e., with probability 1-o(1)) remain connected under random failure if and only if they have no isolated nodes. This simple, yet powerful, result subsequently allows us to derive in closed-form the probability that a P2P network develops isolated nodes, and therefore partitions, …


Nil Is Not Nothing: Recognition Of Chinese Network Informal Language Expressions, Yunqing Xia, Wong, Wei Gao, Wei Gao Oct 2005

Nil Is Not Nothing: Recognition Of Chinese Network Informal Language Expressions, Yunqing Xia, Wong, Wei Gao, Wei Gao

Research Collection School Of Computing and Information Systems

Informal language is actively used in network-mediated communication, e.g. chat room, BBS, email and text message. We refer the anomalous terms used in such context as network informal language (NIL) expressions. For example, “偶(ou3)” is used to replace “我(wo3)” in Chinese ICQ. Without unconventional resource, knowledge and techniques, the existing natural language processing approaches exhibit less effectiveness in dealing with NIL text. We propose to study NIL expressions with a NIL corpus and investigate techniques in processing NIL expressions. Two methods for Chinese NIL expression recognition are designed in NILER system. The experimental results show that pattern matching method produces …


Poster Session A: Address Auto-Configuration In Mobile Ad Hoc Networks Using Olsr, M.U. Saleem, Shoaib Mukhtar Aug 2005

Poster Session A: Address Auto-Configuration In Mobile Ad Hoc Networks Using Olsr, M.U. Saleem, Shoaib Mukhtar

International Conference on Information and Communication Technologies

Mobile Ad Hoc Networks is dynamic multi-hop network that is formed by a set of mobile wireless nodes that are sharing the same bandwidth. So every node possibly acts as a host as well as a router. In traditional networks, hosts can depend on the central servers like DHCP for IP assignment and management, but it cannot be extended to MANET due to its distributed and dynamic nature. Many solutions have been proposed, amongst them some are try to extend the stateless configuration of IPv6 for MANET; others distribute IP addresses among nodes (using binary distribution). Most of these proposed …


Keynote: The Segmentation Problem In Arabic Character Recognition: The State Of The Art, Ahmed M. Zeki Aug 2005

Keynote: The Segmentation Problem In Arabic Character Recognition: The State Of The Art, Ahmed M. Zeki

International Conference on Information and Communication Technologies

Arabic characters are used in several languages other than Arabic, despite to this fact; Arabic Character Recognition (ACR) has not received enough interests by researchers. Little researchprogress has been achieved comparing to the one done on the Latin or Chinese and the solutions available in the market are still far from being perfect. However, recent years have shown a considerable increase in the number of research papers. The cursive nature of Arabic writing makes the process of recognition a very challenging one. Several methods to segment the Arabic words into characters have been proposed in the past two decades. This …


A Visual Tool For Trellis Construction And Decoder Debugging Rac Array Codes, Lami Kaya, Muhammad -Al- Qudah Aug 2005

A Visual Tool For Trellis Construction And Decoder Debugging Rac Array Codes, Lami Kaya, Muhammad -Al- Qudah

International Conference on Information and Communication Technologies

We have developed a visual tool for can be added to a specific RAC array positions and their effect can be easily determined by the help of the visual tool. The program environment has been set in a adaptive manner in order to change different parameters of the RAC codes and see their effect directly. decoding of row and column (RAC) array codes. The visual tool provides interface to view all paths corresponding selected input information bits. Errors constructing trellis diagram and tracing Viterbi.


A Performance Comparison Of Data Encryption Algorithms, Aamer Nadeem, Dr. M. Younus Javed Aug 2005

A Performance Comparison Of Data Encryption Algorithms, Aamer Nadeem, Dr. M. Younus Javed

International Conference on Information and Communication Technologies

The principal goal guiding the design of any encryption algorithm must be security against unauthorized attacks. However, for all practical applications, performance and the cost of implementation are also important concerns. A data encryption algorithm would not be of much use if it is secure enough but slow in performance because it is a common practice to embed encryption algorithms in other applications such as e-commerce, banking, and online transaction processing applications. Embedding of encryption algorithms in other applications also precludes a hardware implementation, and is thus a major cause of degraded overall performance of the system. In this paper, …


Using Agents For Unification Of Information Extraction And Data Mining, Sharjeel Imtiaz, Azmat Hussain, Dr. Sikandar Hiyat Aug 2005

Using Agents For Unification Of Information Extraction And Data Mining, Sharjeel Imtiaz, Azmat Hussain, Dr. Sikandar Hiyat

International Conference on Information and Communication Technologies

Early work for unification of information extraction and data mining is motivational and problem stated work. This paper proposes a solution framework for unification using intelligent agents. A Relation manager agent extracted feature with cross feedback approach and also provide a Unified Undirected graphical handle. An RPM agent an approach to minimize loop back proposes pooling and model utilization with common parameter for both text and entity level abstractions.


Visualization Of Retrieved Positive Data Using Blending Function, Muhammad Shoaib, Habib -Ur- Rehman, Dr. Abad Ali Shah Aug 2005

Visualization Of Retrieved Positive Data Using Blending Function, Muhammad Shoaib, Habib -Ur- Rehman, Dr. Abad Ali Shah

International Conference on Information and Communication Technologies

Data visualization is an important technique used in data mining. We present the retrieved data into visual format to discover features and trends inherent to the data. Some features of the data to be retrieved are already known to us. Visualization should preserve these known features inherent to the data. Positivity is one such known feature that is inherent to most of the scientific and business data sets. For example, mass, volume and percentage concentration are meaningful only when they are positive values. However certain visualization techniques do not guarantee to preserve this feature while constructing visualization of retrieved data …


Mobility-Pattern Based Localization Update Algorithm For Mobile Wireless Sensor Networks, Mohammad Yacoub Al-Laho Jul 2005

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 …


Automatically Discovering The Number Of Clusters In Web Page Datasets, Zhongmei Yao Jun 2005

Automatically Discovering The Number Of Clusters In Web Page Datasets, Zhongmei Yao

Computer Science Faculty Publications

Clustering is well-suited for Web mining by automatically organizing Web pages into categories, each of which contains Web pages having similar contents. However, one problem in clustering is the lack of general methods to automatically determine the number of categories or clusters. For the Web domain in particular, currently there is no such method suitable for Web page clustering. In an attempt to address this problem, we discover a constant factor that characterizes the Web domain, based on which we propose a new method for automatically determining the number of clusters in Web page data sets. We discover that the …