Computer Engineering Commons^™

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 …

Safdetection:Sensor Analysis Based Fault Detection In Tightly-Coupledmulti-Robot Team Tasks, Xingyan Li

Doctoral Dissertations

This dissertation addresses the problem of detecting faults based on sensor analysis for tightly-coupled multi-robot team tasks. The approach I developed is called SAFDetection, which stands for Sensor Analysis based Fault Detection, pronounced “Safe Detection”. When dealing with robot teams, it is challenging to detect all types of faults because of the complicated environment they operate in and the large spectrum of components used in the robot system. The SAFDetection approach provides a novel methodology for detecting robot faults in situations when motion models and models of multi-robot dynamic interactions are unavailable. The fundamental idea of SAFDetection is to build …

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.

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 …

Estimating Risk Under Interval Uncertainty: Sequential And Parallel Algorithms, Vladik Kreinovich, Hung T. Nguyen, Songsak Sriboonchitta

Departmental Technical Reports (CS)

In traditional econometrics, the quality of an individual investment -- and of the investment portfolio -- is characterized by its expected return and its risk (variance). For an individual investment or portfolio, we can estimate the future expected return and a future risk by tracing the returns x₁, ..., x_n of this investment (and/or similar investments) over the past years, and computing the statistical characteristics based on these returns. The return (per unit investment) is defined as the selling of the corresponding financial instrument at the ends of, e.g., a one-year period, divided by the buying price …

Intelligence Techniques Are Needed To Further Enhance The Advantage Of Groups With Diversity In Problem Solving, Oscar Castillo, Patricia Melin, J. Esteban Gamez, Vladik Kreinovich, Olga Kosheleva

Departmental Technical Reports (CS)

In practice, there are many examples when the diversity in a group enhances the group's ability to solve problems -- and thus, leads to more efficient groups, firms, schools, etc. Several papers, starting with the pioneering research by Scott E. Page from the University of Michigan at Ann Arbor, provide a theoretical justification for this known empirical phenomenon. However, when the general advise of increasing diversity is transformed into simple-to-follow algorithmic rules (like quotas), the result is not always successful. In this paper, we prove that the problem of designing the most efficient group is computationally difficult (NP-hard). Thus, in …

Mathematical Justification Of Spectral/Covariance Techniques: On The Example Of Arc Detection, Jan Beck, David Nemir, Vladik Kreinovich

Departmental Technical Reports (CS)

Detecting arcing faults is an important but difficult-to-solve practical problem. Many existing methods of arc detection are based upon acquiring a signal that is proportional to current and then making an analysis of the signal's power spectrum (or, equivalently, its covariance function). Since the power spectrum, i.e., the absolute values of the Fourier transform, carries only partial information about the signal, a natural question is: why should we restrict ourselves to the use of this partial information? A related question is caused by the fact that even the most efficient methods still miss some arcing faults and/or lead to false …

Computing With Tensors: Potential Applications Of Physics-Motivated Mathematics To Computer Science, Martine Ceberio, Vladik Kreinovich

Departmental Technical Reports (CS)

In this paper, we explain what are tensors and how tensors can help in computing.

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 …

Ballot Mark Detection, Elisa H. Barney Smith, Daniel Lopresti, George Nagy

Electrical and Computer Engineering Faculty Publications and Presentations

Optical mark sensing, i.e., detecting whether a "bubble" has been filled in, may seem straightforward. However, on US election ballots the shape, intensity, size and position of the marks, while specified, are highly variable due to a diverse electorate. The ballots may be produced and scanned by poorly maintained equipment. Yet near-perfect results are required. To improve the current technology, which has been subject to criticism, components of a process for identifying marks on an optical sense ballot are evaluated. When marked synthetic ballots are compared to an unmarked ballot, the absolute difference of adaptive thresholded images gives best detection …

Mapping Reality Into Virtual Worlds, Josh Mcfarlane

Computer Science and Computer Engineering Undergraduate Honors Theses

As virtual worlds become more prevalent, they become increasingly useful as a means of information dissemination. This thesis examines the possible connections between real world objects and their virtual world counterparts. We look at how, by attaching sensors to an object, or by using a smart object with embedded sensors, the information can be relayed to a server. From this information, it will be possible to create a duplicate object in the virtual world and have it mirror the real world object in terms of state and movement. Almost all current solutions for remotely viewing a room or area are …

Steganography In Ipv6, Barret Miller

Computer Science and Computer Engineering Undergraduate Honors Theses

Steganography is the process of hiding a secret message within another message such that it is difficult to detect the presence of the secret message. In other words, the existence of the secret message is hidden. A covert channel refers to the actual medium that is used to communicate the information such as a message, image, or file. This honors thesis uses steganography within the source address fields of Internet Protocol Version 6 (IPv6) packets to create a covert channel through which clandestine messages are passed from one party to another. A fully functional computer program was designed and written …

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

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 …

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 …

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

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

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, …

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 …

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.

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.

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 …

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 …

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.

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.

Leading Firms As Knowledge Gatekeepers In A Networked Environment, Deogratias Harorimana Mr

Dr Deogratias Harorimana

This chapter introduces the role of the knowledge gatekeeper as a mechanism by which knowledge is created and transferred in a networked environment. Knowledge creation and transfer are essential for building a knowledge based economy. The chapter considers obstacles that inhibit this process and argues that leading firms create a shared socio-cultural context that enables the condivision of tacit meanings and codification of knowledge. Leading firms act as gatekeepers of knowledge through the creation of shared virtual platforms. There will be a leading firm that connects several networks of clients and suppliers may not interact directly with one another, but …

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.

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

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

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 …