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Full-Text Articles in Engineering

Dependence Of The Performance Of Single Photon Avalanche Diodes On The Multiplication Region Width, David A. Ramirez, Majeed M. Hayat, Mark A. Itzler Dec 2008

Dependence Of The Performance Of Single Photon Avalanche Diodes On The Multiplication Region Width, David A. Ramirez, Majeed M. Hayat, Mark A. Itzler

Electrical and Computer Engineering Faculty Research and Publications

The dependence of the performance of separate-absorption-multiplication (SAM) single-photon avalanche diodes (SPADs) on the width of the multiplication region is theoretically investigated. The theory is applied to SAM SPADs with InP homojunction multiplication regions and InAlAs-InP heterojunction multiplication regions. In both cases the absorber layer is InGaAs. Two scenarios for the dark counts are considered: (i) low-temperature operation, when the number of dark carriers is dominated by field-assisted mechanisms of band-to-band tunneling and tunneling through defects; and (ii) room-temperature operation, when the number of dark carriers in the multiplication region is dominated by the generation/recombination mechanism. The analysis utilizes a …


A Reconfigurable Motor For Experimental Emulation Of Stator Winding Inter-Turn And Broken Bar Faults In Polyphase Induction Machines (Journal Article), Chia-Chou Yeh, Gennadi Y. Sizov, Ahmed Sayed-Ahmed, Nabeel Demerdash, Richard J. Povinelli, Edwin E. Yaz, Dan M. Ionel Dec 2008

A Reconfigurable Motor For Experimental Emulation Of Stator Winding Inter-Turn And Broken Bar Faults In Polyphase Induction Machines (Journal Article), Chia-Chou Yeh, Gennadi Y. Sizov, Ahmed Sayed-Ahmed, Nabeel Demerdash, Richard J. Povinelli, Edwin E. Yaz, Dan M. Ionel

Electrical and Computer Engineering Faculty Research and Publications

The benefits and drawbacks of a 5-hp reconfigurable induction motor, which was designed for experimental emulation of stator winding interturn and broken rotor bar faults, are presented in this paper. It was perceived that this motor had the potential of quick and easy reconfiguration to produce the desired stator and rotor faults in a variety of different fault combinations. Hence, this motor was anticipated to make a useful test bed for evaluation of the efficacy of existing and new motor fault diagnostics techniques and not the study of insulation failure mechanisms. Accordingly, it was anticipated that this reconfigurable motor would …


Distributed Control For Robotic Swarms Using Centroidal Voronoi Tessellations, Shelley Rounds Dec 2008

Distributed Control For Robotic Swarms Using Centroidal Voronoi Tessellations, Shelley Rounds

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis introduces a design combining an emerging area in robotics with a well established mathematical research topic: swarm intelligence and Voronoi tessellations, respectively. The main objective for this research is to design an economical and robust swarm system to achieve distributed control. This research combines swarm intelligence with Voronoi tessellations to localize a source and create formations. Extensive software coding must be implemented for this design, such as the development of a discrete centroidal Voronoi tessellation (CVT) algorithm.

The ultimate purpose of this research is to advance the existing Mobile Actuator and Sensor Network (MASnet) platform to eventually develop …


Application Of Parent-Child Uav Tasking For Wildfire Detection And Response, Stephen T. Kubik Dec 2008

Application Of Parent-Child Uav Tasking For Wildfire Detection And Response, Stephen T. Kubik

Master's Theses

In recent years, unmanned aerial vehicles (UAVs) have become a dominant force in the aerospace industry. Recent technological developments have moved these aircraft from remote operation roles to more active response missions. Of particular interest is the possibility of applying UAVs toward solving complex problems in long-endurance missions. Under that belief, the feasibility of utilizing UAVs for wildfire detection and response was investigated in a partnership that included NASA’s Aeronautics Research Mission Directorate and Science Mission Directorate, and the United States Forest Service. Under NASA’s Intelligent Mission Management (IMM) project, research was conducted to develop a mission architecture that would …


Gene Order Phylogeny Of The Genus Prochlorococcus, Haiwei Luo, Jian Shi, William Arndt, Jijun Tang, Robert Friedman Dec 2008

Gene Order Phylogeny Of The Genus Prochlorococcus, Haiwei Luo, Jian Shi, William Arndt, Jijun Tang, Robert Friedman

Faculty Publications

Background
Using gene order as a phylogenetic character has the potential to resolve previously unresolved species relationships. This character was used to resolve the evolutionary history within the genus Prochlorococcus, a group of marine cyanobacteria.

Methodology/Principal Findings
Orthologous gene sets and their genomic positions were identified from 12 species of Prochlorococcus and 1 outgroup species of Synechococcus. From this data, inversion and breakpoint distance-based phylogenetic trees were computed by GRAPPA and FastME. Statistical support of the resulting topology was obtained by application of a 50% jackknife resampling technique. The result was consistent and congruent with nucleotide sequence-based and gene-content based …


A Special-Purpose Architecture For Solving The Breakpoint Median Problem, Jason D. Bakos, Panormitis E. Elenis Dec 2008

A Special-Purpose Architecture For Solving The Breakpoint Median Problem, Jason D. Bakos, Panormitis E. Elenis

Faculty Publications

In this paper, we describe the design for a co-processor for whole-genome phylogenetic reconstruction. Our current design performs a parallelized breakpoint median computation, which is an expensive component of the overall application. When implemented on a field-programmable gate array (FPGA), our hardware breakpoint median achieves a maximum speedup of 1005times over software. When the coprocessor is used to accelerate the entire reconstruction procedure, we achieve a maximum application speedup of 417times. The results in this paper suggest that FPGA-based acceleration is a promising approach for computationally expensive phylogenetic problems, in spite of the fact that the involved algorithms are based …


A Three-Dimensional Pattern-Space Representation For Volumetric Arrays, William C. Barott, Paul G. Steffes Dec 2008

A Three-Dimensional Pattern-Space Representation For Volumetric Arrays, William C. Barott, Paul G. Steffes

Publications

A three-dimensional pattern-space representation is presented for volumetric arrays. In this representation, the radiation pattern of an array is formed by the evaluation of the three-dimensional pattern-space on a spherical surface. The scan angle of the array determines the position of this surface within the pattern-space. This pattern-space representation is used in conjunction with a genetic algorithm to minimize the sidelobe levels exhibited by a thinned volumetric array during scanning.


Graphical User Interfaces As Updatable Views, James Felger Terwilliger Nov 2008

Graphical User Interfaces As Updatable Views, James Felger Terwilliger

Dissertations and Theses

In contrast to a traditional setting where users express queries against the database schema, we assert that the semantics of data can often be understood by viewing the data in the context of the user interface (UI) of the software tool used to enter the data. That is, we believe that users will understand the data in a database by seeing the labels, dropdown menus, tool tips, help text, control contents, and juxtaposition or arrangement of controls that are built in to the user interface. Our goal is to allow domain experts with little technical skill to understand and query …


Multi-Break Rearrangements And Breakpoint Re-Uses: From Circular To Linear Genomes, Max A. Alekseyev Nov 2008

Multi-Break Rearrangements And Breakpoint Re-Uses: From Circular To Linear Genomes, Max A. Alekseyev

Faculty Publications

Multi-break rearrangements break a genome into multiple fragments and further glue them together in a new order. While 2-break rearrangements represent standard reversals, fusions, fissions, and translocations, 3-break rearrangements represent a natural generalization of transpositions. Alekseyev and Pevzner (2007a, 2008a) studied multi-break rearrangements in circular genomes and further applied them to the analysis of chromosomal evolution in mammalian genomes. In this paper, we extend these results to the more difficult case of linear genomes. In particular, we give lower bounds for the rearrangement distance between linear genomes and for the breakpoint re-use rate as functions of the number and proportion …


Improving Reversal Median Computation Using Commuting Reversals And Cycle Information, William Arndt, Jijun Tang Nov 2008

Improving Reversal Median Computation Using Commuting Reversals And Cycle Information, William Arndt, Jijun Tang

Faculty Publications

In the past decade, genome rearrangements have attracted increasing attention from both biologists and computer scientists as a new type of data for phylogenetic analysis. Methods for reconstructing phylogeny from genome rearrangements include distance-based methods, MCMC methods, and direct optimization methods. The latter, pioneered by Sankoff and extended with the software suites GRAPPA and MGR, is the most accurate approach, but is very limited due to the difficulty of its scoring procedure—it must solve multiple instances of the reversal median problem to compute the score of a given tree. The reversal median problem is known to be NP-hard and all …


Isolation Of Methyl Laurate From Coconut Oil As Raw Material For Fatty Alcohol Sulfate, Rita Arbianti, Tania Surya Utami, Astri Nugroho Nov 2008

Isolation Of Methyl Laurate From Coconut Oil As Raw Material For Fatty Alcohol Sulfate, Rita Arbianti, Tania Surya Utami, Astri Nugroho

Makara Journal of Technology

Isolation of Methyl Laurate from Coconut Oil as Raw Material for Fatty Alcohol Sulfate. Methyl laurate is a raw or base material for many industries, including surfactant industries. In this research, coconut oil (VCO) is transesterified with methanol to produce methyl ester, using NaOH as the catalyst. Methyl laurate is then separated by method based on the difference in melting point. This research focuses at determining the effects of some variables in transesterification on the concentration of produced methyl laurate. The variables are temperature (40 oC, 50 oC, 60 oC, 80 oC), time of transesterification reaction (0,5 hour, 1 hour, …


The Decompositioning Of Volatile-Matter Of Tanjung Enim Coal By Using Thermogravimetry Analyzer (Tga), Nukman Nukman Nov 2008

The Decompositioning Of Volatile-Matter Of Tanjung Enim Coal By Using Thermogravimetry Analyzer (Tga), Nukman Nukman

Makara Journal of Technology

The Decompositioning of Volatile-Matter of Tanjung Enim Coal by using Thermogravimetry Analyzer (TGA). Coal is a nature material which a kind of energy source. The decompotition of coal could analyze by heat treated using thermogravimetry analyzer. The decomposition of the volatile matter for three kinds of Tanjung Enim coal could be known. The value of activation energy that be found diference, then for Semi Anthracite, Bitumonius and Sub Bituminous Coal, the initial temperatures are 60.8 oC, 70.7 oC, 97.8oC, and the last temperatures are 893.8 oC, 832 oC, 584.6oC.


Phase Unwrapping Insar Image Using Local Energy Minimization Approach, Kusworo Adi, Tati L.R. Mengko, Andriyan B. Suksmono, Hendra Gunawan Nov 2008

Phase Unwrapping Insar Image Using Local Energy Minimization Approach, Kusworo Adi, Tati L.R. Mengko, Andriyan B. Suksmono, Hendra Gunawan

Makara Journal of Technology

Phase Unwrapping InSAR Image Using Local Energy Minimization Approach. Reconstruction process of phase data from its cover is called Phase Unwrapping (PU). Ideally, without any noise phrase, singularity, and aliasing problems, the phase information can be unwrapped easily. However, in fact, the phase data actually always get noise disturbance and discontinuity. The PU process becomes more complicated and needs a better PU algorithm to address the problems properly. In this research, the local PU algorithm is developed using minimization of close related firstorder pixels energy approach. In this method, the energy difference between four close related pixels is counted, followed …


Two Element Microstrip Antenna Array With Defected Ground Structure, Fitri Yuli Zulkifli, Eko Tjipto Rahardjo, Muhamad Asvial, Djoko Hartanto Nov 2008

Two Element Microstrip Antenna Array With Defected Ground Structure, Fitri Yuli Zulkifli, Eko Tjipto Rahardjo, Muhamad Asvial, Djoko Hartanto

Makara Journal of Technology

Two Element Microstrip Antenna Array with Defected Ground Structure. This paper presents a two element microstrip antenna array using trapezium shape defected ground structure (DGS). The DGS is inserted in the ground plane between two elements of antenna array. Insertion of the DGS is intended to suppress the mutual coupling effect produced by antenna array. Simulation and measurement results were taken and compared between antenna array with and without DGS. Measurement results show that the antenna with DGS compared to antenna without DGS can suppress mutual coupling effect to 7.9 dB, improve the return loss to 33.29% from -30.188 dB …


Neutron Irradiation On Ss316 Material For Radioactive Endovascular Stent Production, Rohadi Awaludin, Abidin Abidin, Sriyono Sriyono Nov 2008

Neutron Irradiation On Ss316 Material For Radioactive Endovascular Stent Production, Rohadi Awaludin, Abidin Abidin, Sriyono Sriyono

Makara Journal of Technology

Neutron Irradiation on SS316 Material for Radioactive Endovascular Stent Production. It was reported that restenosis could be prevented by radioactive endovascular stent. SS316 material of endovascular stent has been irradiated at pneumatic rabbit system of G.A. Siwabessy reactor for 5 minutes for producing radioactive stent by neutron activation. After 10 days of decay, the irradiated SS316 was measured by gamma spectrometer. The radioisotopes of 51Cr, 59Fe and 60Co were detected in the irradiated SS316 with radioactivity of 5990, 107 and 109 Bq/mg respectively. The Calculation results showed that radioisotopes of 51Cr, 59Fe and 55Fe were produced by neutron activation. The …


Physical Characteristics And Utilization Oft The Karst Beaches In Kabupaten Gunungkidul, Astrid Damayanti, Ranum Ayuningtyas Nov 2008

Physical Characteristics And Utilization Oft The Karst Beaches In Kabupaten Gunungkidul, Astrid Damayanti, Ranum Ayuningtyas

Makara Journal of Technology

Physical Characteristics and Utilization oft the Karst Beaches in Kabupaten Gunungkidul. Karsts beaches at Gunungkidul Regency (Baron, Kukup, Sepanjang, Drini, Krakal, Ngandong, and Sundak), located in south of Daerah Istimewa Yogyakarta Province, have economic potential. Even they have similarity in geological condition (genesis and morphological processes), but they have different physical characteristics. Based on result of observation environment on morphological conditions and spatial analysis method, we found the proper utilization of the beaches.


Hydrogen Absorption In Weldments Of Overlaid Claded Pressure Vessel, Ronnie Higuchi Rusli Nov 2008

Hydrogen Absorption In Weldments Of Overlaid Claded Pressure Vessel, Ronnie Higuchi Rusli

Makara Journal of Technology

Cracks was found in type 347 stainless steel internal attachment welds of a reactor for a high temperature, and high pressure hydrogen service. One of the possible causes of cracking is low cycle fatigue cracking induced by repetition of thermal stress to embrittled weld metal. Type 347 weld metal loses its ductility by presence of sigma phase and hydrogen.


Spectral Response Surfaces And The Ringing Response Of Offshore Structures, I Ketut Suastika Nov 2008

Spectral Response Surfaces And The Ringing Response Of Offshore Structures, I Ketut Suastika

Makara Journal of Technology

A method, called spectral response surface method, is proposed for the study of the ringing phenomenon of offshore structures. Newman’s results for diffraction force on a column were reformulated in terms of the frequency components of the ocean surface and their Hilbert transforms. Using a first-order reliability method together with a dynamic model for the structural response, it is straightforward to calculate the ocean surface history most likely to generate an extreme ringing response and the ringing response history.


An Aspect-Based Approach To Checking Design Constraints At Run-Time, Yoonsik Cheon, Carmen Avila, Steve Roach, Cuauhtemoc Munoz, Neith Estrada, Valeria Fierro, Jessica Romo Nov 2008

An Aspect-Based Approach To Checking Design Constraints At Run-Time, Yoonsik Cheon, Carmen Avila, Steve Roach, Cuauhtemoc Munoz, Neith Estrada, Valeria Fierro, Jessica Romo

Departmental Technical Reports (CS)

Design decisions and constraints of a software system can be specified precisely using a formal notation such as the Object Constraint Language (OCL). However, they are not executable, and assuring the conformance of an implementation to its design is hard. The inability of expressing design constraints in an implementation and checking them at runtime invites, among others, the problem of design drift and corrosion. We propose runtime checks as a solution to mitigate this problem. The key idea of our approach is to translate design constraints written in a formal notation such as OCL into aspects that, when applied to …


On Chromatic Numbers Of Space-Times: Open Problems, Olga Kosheleva, Vladik Kreinovich Nov 2008

On Chromatic Numbers Of Space-Times: Open Problems, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

No abstract provided.


A Paradox Of Altruism: How Caring About Future Generations Can Result In Poverty For Everyone (Game-Theoretic Analysis), Tanja Magoc, Vladik Kreinovich Nov 2008

A Paradox Of Altruism: How Caring About Future Generations Can Result In Poverty For Everyone (Game-Theoretic Analysis), Tanja Magoc, Vladik Kreinovich

Departmental Technical Reports (CS)

Political and social activists are rightfully concerned about future generations: whenever a country borrows money, or an environmental situation worsens, this means, in effect, that we impose an additional burdens on future generations. There is clearly a conflict between the present generation's actions and interests and the welfare of the future generations. There exists a mathematical toolbox that provides solutions to many well-defined conflict situations: namely, the toolbox of game theory. It therefore seems reasonable to apply game theory techniques to the conflict between the generations. In this paper, we show that we need to be very cautious about this …


Viability Of Travel-Time Sensitivity Testing For Estimating Uncertainty Of Tomographic Velocity Models: A Case Study, Matthew G. Averill, Kate C. Miller, Vladik Kreinovich, Aaron A. Velasco Nov 2008

Viability Of Travel-Time Sensitivity Testing For Estimating Uncertainty Of Tomographic Velocity Models: A Case Study, Matthew G. Averill, Kate C. Miller, Vladik Kreinovich, Aaron A. Velasco

Departmental Technical Reports (CS)

Seismic tomography is now a common approach to estimating velocity structure of the Earth, regardless of whether the data sources are earthquake recordings or controlled sources such as explosions, airguns or Vibroseis. Seismic tomography is convenient to implement because it requires little to no a priori knowledge of Earth structure and is much less time consuming than forward modeling schemes. Despite its convenience, the method still lacks satisfactory quantitative assessments of model reliability. Here we explore the viability of applying travel-time sensitivity testing that uses a modified Cauchy distribution as its statistical foundation to assessing the uncertainty in velocity models …


A New Simplified Derivation Of Nash Bargaining Solution, Tanja Magoc, Vladik Kreinovich Nov 2008

A New Simplified Derivation Of Nash Bargaining Solution, Tanja Magoc, Vladik Kreinovich

Departmental Technical Reports (CS)

In the 1950s, the Nobel Prize winner John F. Nash has shown that under certain conditions, the best solution to the bargaining problem is when the product of the (increase in) utilities is the largest. Nash's derivation assumed that we are looking for strategies that assign a single situation to each bargaining situation. In this paper, we propose a simplified derivation of Nash bargaining solution that does not requires this assumption.


Irrelevance, Polymorphism, And Erasure In Type Theory, Richard Nathan Mishra-Linger Nov 2008

Irrelevance, Polymorphism, And Erasure In Type Theory, Richard Nathan Mishra-Linger

Dissertations and Theses

Dependent type theory is a proven technology for verified functional programming in which programs and their correctness proofs may be developed using the same rules in a single formal system. In practice, large portions of programs developed in this way have no computational relevance to the ultimate result of the program and should therefore be removed prior to program execution. In previous work on identifying and removing irrelevant portions of programs, computational irrelevance is usually treated as an intrinsic property of program expressions. We find that such an approach forces programmers to maintain two copies of commonly used datatypes: a …


Evaluating Shape Correspondence For Statistical Shape Analysis: A Benchmark Study, Brent C. Munsell, Pahal Dalal, Song Wang Nov 2008

Evaluating Shape Correspondence For Statistical Shape Analysis: A Benchmark Study, Brent C. Munsell, Pahal Dalal, Song Wang

Faculty Publications

This paper introduces a new benchmark study to evaluate the performance of landmark-based shape correspondence used for statistical shape analysis. Different from previous shape-correspondence evaluation methods, the proposed benchmark first generates a large set of synthetic shape instances by randomly sampling a given statistical shape model that defines a ground-truth shape space. We then run a test shape-correspondence algorithm on these synthetic shape instances to identify a set of corresponded landmarks. According to the identified corresponded landmarks, we construct a new statistical shape model, which defines a new shape space. We finally compare this new shape space against the ground-truth …


Implementing Arabic-To-English Machine Translation Using The Role And Reference Grammar Linguistic Model, Yasser Salem, Arnold Hensman, Brian Nolan Oct 2008

Implementing Arabic-To-English Machine Translation Using The Role And Reference Grammar Linguistic Model, Yasser Salem, Arnold Hensman, Brian Nolan

Conference Papers

This paper presents work-in-progress investigating the development of a rule-based lexical framework for Arabic language processing using the Role and Reference Grammar (RRG) linguistic model. A system, called UniArab is introduced in this research to support the framework. The paper outlines the conceptual structure of UniArab System, which utilizes the framework and translates the Arabic language into another natural language. Also, this paper explores how the characteristics of the Arabic language will effect the development of a Machine Translation (MT) tool from Arabic to English. Several distinguishing features of Arabic pertinent to MT will be explored in detail with reference …


Minimum Mean-Squared Error Estimation Of Mel-Frequency Cepstral Coefficients Using A Novel Distortion Model, Kevin M. Indrebo, Richard J. Povinelli, Michael T. Johnson Oct 2008

Minimum Mean-Squared Error Estimation Of Mel-Frequency Cepstral Coefficients Using A Novel Distortion Model, Kevin M. Indrebo, Richard J. Povinelli, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

In this paper, a new method for statistical estimation of Mel-frequency cepstral coefficients (MFCCs) in noisy speech signals is proposed. Previous research has shown that model-based feature domain enhancement of speech signals for use in robust speech recognition can improve recognition accuracy significantly. These methods, which typically work in the log spectral or cepstral domain, must face the high complexity of distortion models caused by the nonlinear interaction of speech and noise in these domains. In this paper, an additive cepstral distortion model (ACDM) is developed, and used with a minimum mean-squared error (MMSE) estimator for recovery of MFCC features …


Asymmetric Information Measures: How To Extract Knowledge From An Expert So That The Expert's Effort Is Minimal, Hung T. Nguyen, Vladik Kreinovich, Elizabeth N. Kamoroff Oct 2008

Asymmetric Information Measures: How To Extract Knowledge From An Expert So That The Expert's Effort Is Minimal, Hung T. Nguyen, Vladik Kreinovich, Elizabeth N. Kamoroff

Departmental Technical Reports (CS)

Knowledge acquisition is when we ask experts questions, and put the answers into the computer system. Since this is a very time-consuming task, it is desirable to minimize the effort of an expert.

As a crude estimate for this effort, we can take a number of binary (yes-no) questions that we ask. The procedure that minimizes this number is binary search.

This approach does not take into account that people often feel more comfortable answering "yes" than answering "no". So, to make our estimates more realistic, we will take into consideration that for a negative answer the effort is bigger. …


Optimisation Of Multicast Routing In Wireless Mesh Networks, Brian Keegan, Karol Kowalik, Mark Davis Oct 2008

Optimisation Of Multicast Routing In Wireless Mesh Networks, Brian Keegan, Karol Kowalik, Mark Davis

Conference papers

In recent years Wireless Mesh Networks have been deployed and grown in popularity in many metropolitan areas. The deployment of such networks has allowed clients to gain access to publicly available broadband networks. The implementation of wireless mesh networks requires that backhaul services (traditionally carried by wired networks) be maintained via wireless mesh points. Because of their structure, wireless mesh networks provide an excellent means for targeting a large group of end users or simply to relay data. This may be achieved by means of broadcasting or more specifically multicasting. The lack of standards and support for multicasting over wireless …


Current Financial Crisis And Inadequate Uncertainty Processing: A Comment, Tanja Magoc, Vladik Kreinovich Oct 2008

Current Financial Crisis And Inadequate Uncertainty Processing: A Comment, Tanja Magoc, Vladik Kreinovich

Departmental Technical Reports (CS)

No abstract provided.