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2006

Missouri University of Science and Technology

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Articles 1 - 30 of 131

Full-Text Articles in Physical Sciences and Mathematics

Differential Electron Emission For Single And Multiple Ionization Of Argon By 500 Ev Positrons, Jared M. Gavin, Robert D. Dubois, O. G. De Lucio Dec 2006

Differential Electron Emission For Single And Multiple Ionization Of Argon By 500 Ev Positrons, Jared M. Gavin, Robert D. Dubois, O. G. De Lucio

Physics Faculty Research & Creative Works

Triply differential electron emission cross sections are measured for single ionization of argon by 500 eV positrons. Data are presented for coincidences between projectiles scattered into angles of 3° and electrons with emission energies less than 10 eV that are observed between 45 and 135° along the beam direction. For interpretation, these are compared to cosine squared representations of the binary and recoil lobes which are convoluted over experimental parameters. Singly differential electron emission data for double and triple ionization by positrons are also presented.

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Two-Loop Bethe Logarithms For Non- S Levels, Ulrich D. Jentschura Dec 2006

Two-Loop Bethe Logarithms For Non- S Levels, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

Two-loop Bethe logarithms are calculated for excited P and D states in hydrogenlike systems, and estimates are presented for all states with higher angular momenta. These results complete our knowledge of the P and D energy levels in hydrogen at the order of α8 mec2, where me is the electron mass and c is the speed of light, and scale as Z6, where Z is the nuclear charge number. Our analytic and numerical calculations are consistent with the complete absence of logarithmic terms of order (απ)2 (Zα)6 ln [(Zα)-2] …

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Optimal Placement And Control Of Unified Power Flow Control Devices Using Evolutionary Computing And Sequential Quadratic Programming, Radha P. Kalyani, Mariesa Crow, Daniel R. Tauritz Nov 2006

Optimal Placement And Control Of Unified Power Flow Control Devices Using Evolutionary Computing And Sequential Quadratic Programming, Radha P. Kalyani, Mariesa Crow, Daniel R. Tauritz

Electrical and Computer Engineering Faculty Research & Creative Works

A crucial factor effecting modern power systems today is power flow control. An effective means for controlling and improving power flow is by installing fast reacting devices such as a unified power flow controller (UPFC). For maximum positive impact of this device on the power grid, it should be installed at an optimal location and employ an optimal realtime control algorithm. This paper proposes the combination of an evolutionary algorithm (EA) to find the optimal location and sequential quadratic programming (SQP) to optimize the UPFC control settings. Simulations are conducted using the classic IEEE 118 bus test system. For comparison …

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K Α₁ Radiation From Heavy, Heliumlike Ions Produced In Relativistic Collisions, Andrey S. Surzhykov, Ulrich D. Jentschura, Th H. Stohlker, Stephan Fritzsche Nov 2006

K Α₁ Radiation From Heavy, Heliumlike Ions Produced In Relativistic Collisions, Andrey S. Surzhykov, Ulrich D. Jentschura, Th H. Stohlker, Stephan Fritzsche

Physics Faculty Research & Creative Works

Bound-state transitions in few-electron, heavy ions following radiative electron capture are studied within the framework of the density matrix theory and the multiconfiguration Dirac-Fock approach. Special attention is paid to the K α1 (1 s1/2 2 p3/2 1.3PJ=1,2→1s21/2 1SJ=0) radiative decay of heliumlike uranium U90+ projectiles. This decay has recently been observed at the GSI facility in Darmstadt, giving rise to a surprisingly isotropic angular distribution, which is inconsistent with previous experiments and calculations based on a "one-particle" model. We show that the unexpected isotropy essentially results from …

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Analysis Of Two-Dimensional Photoelectron Momentum Spectra And The Effect Of The Long-Range Coulomb Potential In Single Ionization Of Atoms By Intense Lasers, Zhangjin Chen, Toru Morishita, Anh-Thu Le, M. Wickenhauser, X. M. Tong, C. D. Lin Nov 2006

Analysis Of Two-Dimensional Photoelectron Momentum Spectra And The Effect Of The Long-Range Coulomb Potential In Single Ionization Of Atoms By Intense Lasers, Zhangjin Chen, Toru Morishita, Anh-Thu Le, M. Wickenhauser, X. M. Tong, C. D. Lin

Physics Faculty Research & Creative Works

Two-dimensional (2D) electron momentum distributions and energy spectra for multiphoton ionization of atoms by intense laser pulses, calculated by solving the time-dependent Schrödinger equation (TDSE) for different wavelengths and intensities, are compared to those predicted by the strong-field approximation (SFA). It is shown that the momentum spectra at low energies between the TDSE and SFA are quite different and the differences arise largely from the absence of a long-range Coulomb interaction in the SFA. We further found that the low-energy 2D momentum spectra from the TDSE exhibit ubiquitous fanlike features where the number of stripes is due to a single …

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Dynamic Programming-Based Energy-Efficient Rate Adaptation For Wireless Ad Hoc Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani Nov 2006

Dynamic Programming-Based Energy-Efficient Rate Adaptation For Wireless Ad Hoc Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Resource constraints require that ad hoc wireless networks are energy efficient during transmission and rate adaptation. In this paper we propose a novel cross-layer energy-efficient rate adaptation scheme that employs dynamic programming (DP) principle to analytically select the modulation scheme online. The scheme uses channel state information from the physical layer and congestion information from the scheduling layer to select a modulation rate. This online selection maximizes throughput while saving energy and preventing congestion. The simulation results indicate that an increase in throughput by 96% and energy-efficiency by 131% is observed when compared to the Receiver Based AutoRate (RBAR) protocol.

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Mantle Transition Zone Discontinuities Beneath The Baikal Rift And Adjacent Areas, Kelly H. Liu, Stephen S. Gao Nov 2006

Mantle Transition Zone Discontinuities Beneath The Baikal Rift And Adjacent Areas, Kelly H. Liu, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Like most other major continental rifts, the Baikal rift zone (BRZ) in Siberia is presumably underlain by a hot and partially molten mantle, which has a reduced seismic velocity relative to surrounding areas. Recent seismic tomography studies, however, gave conflicting results about the depth extent and even the existence of the low-velocity anomaly beneath the BRZ, suggesting that additional constraints are needed. Here we present results from stacking of about 1700 radial P-to-S receiver functions from a single long-running seismic station, TLY, located at the SW tip of Lake Baikal. A clear uplift of the 410 km discontinuity (d410) with …

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Improving Database Quality Through Eliminating Duplicate Records, Mingzhen Wei, Andrew H. Sung, Martha E. Cather Nov 2006

Improving Database Quality Through Eliminating Duplicate Records, Mingzhen Wei, Andrew H. Sung, Martha E. Cather

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Redundant or duplicate data are the most troublesome problem in database management and applications. Approximate field matching is the key solution to resolve the problem by identifying semantically equivalent string values in syntactically different representations. This paper considers token-based solutions and proposes a general field matching framework to generalize the field matching problem in different domains. By introducing a concept of String Matching Points (SMP) in string comparison, string matching accuracy and efficiency are improved, compared with other commonly-applied field matching algorithms. The paper discusses the development of field matching algorithms from the developed general framework. The framework and corresponding …

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Quantum Dot Potentials: Symanzik Scaling, Resurgent Expansions, And Quantum Dynamics, Andrey S. Surzhykov, Michael Lubasch, Jean Zinn-Justin, Ulrich D. Jentschura Nov 2006

Quantum Dot Potentials: Symanzik Scaling, Resurgent Expansions, And Quantum Dynamics, Andrey S. Surzhykov, Michael Lubasch, Jean Zinn-Justin, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

This article is concerned with a special class of the "double-well- like" potentials that occur naturally in the analysis of finite quantum systems. Special attention is paid, in particular, to the so-called Fokker-Planck potential, which has a particular property: the perturbation series for the ground-state energy vanishes to all orders in the coupling parameter, but the actual ground-state energy is positive and dominated by instanton configurations of the form exp (-a g), where a is the instanton action. The instanton effects are most naturally taken into account within the modified Bohr-Sommerfeld quantization conditions whose expansion leads to the generalized perturbative …

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A P2p Integration Architecture For Protein Resources, K. T. Claypool, Sanjay Kumar Madria Oct 2006

A P2p Integration Architecture For Protein Resources, K. T. Claypool, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

The availability of a direct pathway from a primary sequence (denovo or DNA derived) to macromolecular structure to biological function using computer-based tools is the ultimate goal for a protein scientist. Today's state of the art protein resources and on-going research and experiments provide the raw data that can enable protein scientists to achieve at least some steps of this goal. Thus, protein scientists are looking towards taking their benchtop research from the specific to a much broader base of using the large resources of available electronic information. However, currently the burden falls on the scientist to manually interface with …

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Gravitational Diffraction Radiation, Vitor Cardoso, Marco Cavaglia, Mario Pimenta Oct 2006

Gravitational Diffraction Radiation, Vitor Cardoso, Marco Cavaglia, Mario Pimenta

Physics Faculty Research & Creative Works

We show that if the visible universe is a membrane embedded in a higher-dimensional space, particles in uniform motion radiate gravitational waves because of spacetime lumpiness. This phenomenon is analogous to the electromagnetic diffraction radiation of a charge moving near to a metallic grating. In the gravitational case, the role of the metallic grating is played by the inhomogeneities of the extra-dimensional space, such as a hidden brane. We derive a general formula for gravitational diffraction radiation and apply it to a higher-dimensional scenario with flat compact extra dimensions. Gravitational diffraction radiation may carry away a significant portion of the …

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Adaptive Critic Neural Network Force Controller For Atomic Force Microscope-Based Nanomanipulation, Qinmin Yang, Jagannathan Sarangapani Oct 2006

Adaptive Critic Neural Network Force Controller For Atomic Force Microscope-Based Nanomanipulation, Qinmin Yang, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Automating the task of nanomanipulation is extremely important since it is tedious for humans. This paper proposes an atomic force microscope (AFM) based force controller to push nano particles on the substrates. A block phase correlation-based algorithm is embedded into the controller for the compensation of the thermal drift which is considered as the main external uncertainty during nanomanipulation. Then, the interactive forces and dynamics between the tip and the particle, particle and the substrate are modeled and analyzed. Further, an adaptive critic NN controller based on adaptive dynamic programming algorithm is designed and the task of pushing nano particles …

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Multiple Scattering Mechanisms In Simultaneous Projectile-Electron And Target-Electron Ejection In H⁻ + He Collisions, Michael Schulz, T. Ferger, Daniel Fischer, R. Moshammer, J. D. Ullrich Oct 2006

Multiple Scattering Mechanisms In Simultaneous Projectile-Electron And Target-Electron Ejection In H⁻ + He Collisions, Michael Schulz, T. Ferger, Daniel Fischer, R. Moshammer, J. D. Ullrich

Physics Faculty Research & Creative Works

We studied simultaneous electron ejection from both collision partners in 200-keV H-+He collisions in a kinematically complete experiment by measuring the fully momentum-analyzed recoil ions and both active electrons in coincidence. The data were analyzed in terms of Dalitz spectra, in which the momentum exchange between three particles is plotted simultaneously in a single spectrum. We found that the energy transfer occurs predominantly between the active electrons, but most of the momentum is exchanged in elastic scattering between the cores of the collision partners.

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An Automated Method For Rapid Identification Of Putative Gene Family Members In Plants, Ronald L. Frank, Ajay Mane, Fikret Erçal Sep 2006

An Automated Method For Rapid Identification Of Putative Gene Family Members In Plants, Ronald L. Frank, Ajay Mane, Fikret Erçal

Biological Sciences Faculty Research & Creative Works

Background: Gene duplication events have played a significant role in genome evolution, particularly in plants. Exhaustive searches for all members of a known gene family as well as the identification of new gene families has become increasingly important. Subfunctionalization via changes in regulatory sequences following duplication (adaptive selection) appears to be a common mechanism of evolution in plants and can be accompanied by purifying selection on the coding region. Such negative selection can be detected by a bias toward synonymous over nonsynonymous substitutions. However, the process of identifying this bias requires many steps usually employing several different software programs. We …

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Pervasive Data Access In Wireless And Mobile Computing Environments, Ken C. K. Lee, Wang-Chien Lee, Sanjay Kumar Madria Sep 2006

Pervasive Data Access In Wireless And Mobile Computing Environments, Ken C. K. Lee, Wang-Chien Lee, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

The rapid advance of wireless and portable computing technology has brought a lot of research interests and momentum to the area of mobile computing. One of the research focus is on pervasive data access. with wireless connections, users can access information at any place at any time. However, various constraints such as limited client capability, limited bandwidth, weak connectivity, and client mobility impose many challenging technical issues. In the past years, tremendous research efforts have been put forth to address the issues related to pervasive data access. A number of interesting research results were reported in the literature. This survey …

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Volumes Of Critical Bubbles From The Nucleation Theorem, Gerald Wilemski Sep 2006

Volumes Of Critical Bubbles From The Nucleation Theorem, Gerald Wilemski

Physics Faculty Research & Creative Works

A corollary of the nucleation theorem due to Kashchiev [Nucleation: Basic Theory with Applications (Butterworth-Heinemann, Oxford, 2000)] allows the volume V* of a critical bubble to be determined from nucleation rate measurements. The original derivation was limited to one-component, ideal gas bubbles with a vapor density much smaller than that of the ambient liquid. Here, an exact result is found for multicomponent, nonideal gas bubbles. Provided a weak density inequality holds, this result reduces to Kashchiev's simple form which thus has a much broader range of applicability than originally expected. Limited applications to droplets are also mentioned, and the utility …

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Exploring Relativistic Many-Body Recoil Effects In Highly Charged Ions, R. Soria Orts, Zoltan Harman, Jose R. Crespo Lopez-Urrutia, Anton N. Artemyev, Hjalmar Bruhns, Antonio J. Gonzalez, Ulrich D. Jentschura, Christoph H. Keitel, Alain Lapierre, Vladimir Sergeyevich Mironov, Vladimir M. Shabaev, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka Sep 2006

Exploring Relativistic Many-Body Recoil Effects In Highly Charged Ions, R. Soria Orts, Zoltan Harman, Jose R. Crespo Lopez-Urrutia, Anton N. Artemyev, Hjalmar Bruhns, Antonio J. Gonzalez, Ulrich D. Jentschura, Christoph H. Keitel, Alain Lapierre, Vladimir Sergeyevich Mironov, Vladimir M. Shabaev, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka

Physics Faculty Research & Creative Works

The relativistic recoil effect has been the object of experimental investigations using highly charged ions at the Heidelberg electron beam ion trap. Its scaling with the nuclear charge Z boosts its contribution to a measurable level in the magnetic-dipole (M1) transitions of B- and Be-like Ar ions. The isotope shifts of 36Ar versus 40Ar have been detected with sub-ppm accuracy, and the recoil effect contribution was extracted from the 1s22s22p 2P1/2-2P3/2 transition in Ar13+ and the 1s22s2p 3P1-3P2 transition …

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Microbial Growth And Biofilm Formation In Geologic Media Is Detected With Complex Conductivity Measurements, Caroline A. Davis, Estella A. Atekwana, Eliot A. Atekwana, Lee D. Slater, Silvia Rossbach, Melanie R. Mormile Sep 2006

Microbial Growth And Biofilm Formation In Geologic Media Is Detected With Complex Conductivity Measurements, Caroline A. Davis, Estella A. Atekwana, Eliot A. Atekwana, Lee D. Slater, Silvia Rossbach, Melanie R. Mormile

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Complex conductivity measurements (0.1-1000 Hz) were obtained from biostimulated sand-packed columns to investigate the effect of microbial growth and biofilm formation on the electrical properties of porous media. Microbial growth was verified by direct microbial counts, pH measurements, and environmental scanning electron microscope imaging. Peaks in imaginary (interfacial) conductivity in the biostimulated columns were coincident with peaks in the microbial cell concentrations extracted from sands. However, the real conductivity component showed no discernible relationship to microbial cell concentration. We suggest that the observed dynamic changes in the imaginary conductivity (σ″) arise from the growth and attachment of microbial cells and …

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A Methodology For Structured Object-Oriented Elicitation And Analysis Of Temporal Constraints In Hardware/Software Co-Analysis And Co-Design Of Real-Time Systems, Sun Yan, Xiaoqing Frank Liu, Bruce M. Mcmillin Sep 2006

A Methodology For Structured Object-Oriented Elicitation And Analysis Of Temporal Constraints In Hardware/Software Co-Analysis And Co-Design Of Real-Time Systems, Sun Yan, Xiaoqing Frank Liu, Bruce M. Mcmillin

Computer Science Faculty Research & Creative Works

The hardware/software co-design of a high-quality real-time system relies heavily on the modeling of both the hardware and software components from three aspects: structures, functionalities, and constraints, especially the temporal constraints. However, there is not a systematic process for the elicitation and analysis of temporal constraints in hardware/software co-design. Furthermore, existing object-oriented methods provide no means for the explicit specification of system/component constraints in object models. This paper presents a systematic methodology for structured object-oriented analysis and specification of temporal constraints in hardware/software co-analysis and co-design using an extended High-Order Object-Oriented Modeling Technique (HOOMT). This methodology hierarchically elicits and analyzes …

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An Instance-Based Structured Object Oriented Method For Co-Analysis/Co-Design Of Concurrent Embedded Systems, Matt Ryan, Xiaoqing Frank Liu, Bruce M. Mcmillin, Ying Cheng, Sule Simsek Sep 2006

An Instance-Based Structured Object Oriented Method For Co-Analysis/Co-Design Of Concurrent Embedded Systems, Matt Ryan, Xiaoqing Frank Liu, Bruce M. Mcmillin, Ying Cheng, Sule Simsek

Computer Science Faculty Research & Creative Works

The current object-oriented class-based approaches to hardware/software co-analysis/co-design of embedded systems are limited in their abilities to properly capture the structure of individual instances of hardware and software components and their interactions. This paper discusses a methodology to extend a structured objectoriented hardware/software co-design methodology based on the High Order Object-oriented Modeling Technique (HOOMT) to incorporate instance-based object and behavioral models. The instance-based structured object-oriented methodology will enable description of a system's structure based on individual instances of hardware and software components and specification of the interactions among them. In addition, lattices are introduced to specify the concurrent behavior of …

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Microwave Reflectometry As A Novel Diagnostic Tool For Detection Of Skin Cancers, Pratik Mehta, Kundan Chand, Deepak Narayanswamy, Daryl G. Beetner, R. Zoughi, William V. Stoecker Aug 2006

Microwave Reflectometry As A Novel Diagnostic Tool For Detection Of Skin Cancers, Pratik Mehta, Kundan Chand, Deepak Narayanswamy, Daryl G. Beetner, R. Zoughi, William V. Stoecker

Electrical and Computer Engineering Faculty Research & Creative Works

More than 1 000 000 people are diagnosed with skin cancer each year in the United States, and more than 10 000 people die from the disease. Methods such as visual inspection and dermoscopy are available for early detection of skin cancers, but improvement in accuracy is needed. This paper investigates the use of microwave reflectometry as a potential diagnostic tool for detection of skin cancers. Open-ended coaxial probes were used to measure microwave properties of skin. The influences of measurement parameters such as probe application pressure, power level, and variation in reflection properties of skin with location and hydration …

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Two Energy Efficient Algorithms For Tracking Objects In A Sensor Network, Arvind Rapaka, Sanjay Kumar Madria Jul 2006

Two Energy Efficient Algorithms For Tracking Objects In A Sensor Network, Arvind Rapaka, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

We propose two energy efficient algorithms for locating a target object moving in an area covered by a wireless ad hoc network. The first algorithm developed conserve energy by efficiently identifying sensor nodes, as Home Nodes, and use only local messages between neighboring nodes to follow the trail of the object. Since we avoid the long-range transmission and maximize the localization, the algorithms reduce the communication cost. The dynamic nature of the second algorithm exploits the predefined parameters such as the object velocity. Our algorithm represents query shipping against the conventional data shipping as a means to reduce the amount …

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Erratum: The Emergence Of A Large-Scale Coherent Structure Under Small-Scale Random Bombardments (Communications On Pure And Applied Mathematics (2006) 59:4 (467-500)), Andrew Majda, Xiaoming Wang Jul 2006

Erratum: The Emergence Of A Large-Scale Coherent Structure Under Small-Scale Random Bombardments (Communications On Pure And Applied Mathematics (2006) 59:4 (467-500)), Andrew Majda, Xiaoming Wang

Mathematics and Statistics Faculty Research & Creative Works

No abstract provided.

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Neural Network Based Decentralized Excitation Control Of Large Scale Power Systems, Wenxin Liu, Ganesh K. Venayagamoorthy, Donald C. Wunsch, David A. Cartes, Jagannathan Sarangapani Jul 2006

Neural Network Based Decentralized Excitation Control Of Large Scale Power Systems, Wenxin Liu, Ganesh K. Venayagamoorthy, Donald C. Wunsch, David A. Cartes, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a neural network (NN) based decentralized excitation controller design for large scale power systems. The proposed controller design considers not only the dynamics of generators but also the algebraic constraints of the power flow equations. The control signals are calculated using only local signals. The transient stability and the coordination of the subsystem controllers can be guaranteed. NNs are used to approximate the unknown/imprecise dynamics of the local power system and the interconnections. All signals in the closed loop system are guaranteed to be uniformly ultimately bounded (UUB). Simulation results with a 3-machine power system demonstrate the …

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Hyperspherical Close-Coupling Calculations For Electron-Capture Cross Sections In Low-Energy Ne¹⁰⁺ +H (1s) Collisions, P. Barragan, Anh-Thu Le, C. D. Lin Jul 2006

Hyperspherical Close-Coupling Calculations For Electron-Capture Cross Sections In Low-Energy Ne¹⁰⁺ +H (1s) Collisions, P. Barragan, Anh-Thu Le, C. D. Lin

Physics Faculty Research & Creative Works

We present total and partial electron-capture cross sections for Ne¹⁰⁺ +H (1s) collisions at energies from 0.01 eV to 1 keV using the hyperspherical close-coupling method. Good agreements with the previous calculations by the classical-trajectory Monte-Carlo method are found for total capture cross section, but not for partial cross sections, especially below about 200 eV/amu. We found that the total cross section is mainly due to the population of n=7 channels and only at energies above 50 eV/amu n = 5,6 channels begin to contribute to the total cross section.

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Direct Experimental Evidence For The Atomic Tunneling Of Europium In Crystalline Eu₈Ga₁₆Ge₃₀, Raphäel P. Hermann, Veerle M. Keppens, Pierre Bonville, George S. Nolas, Fernande Grandjean, Gary J. Long, Hans Martin Christen, Bryan C. Chakoumakos, Brian C. Sales, David G. Mandrus Jul 2006

Direct Experimental Evidence For The Atomic Tunneling Of Europium In Crystalline Eu₈Ga₁₆Ge₃₀, Raphäel P. Hermann, Veerle M. Keppens, Pierre Bonville, George S. Nolas, Fernande Grandjean, Gary J. Long, Hans Martin Christen, Bryan C. Chakoumakos, Brian C. Sales, David G. Mandrus

Chemistry Faculty Research & Creative Works

Mössbauer-effect and microwave absorption experimental evidence unambiguously demonstrates the presence of slow, ~450 MHz, tunneling of magnetic europium between four equivalent sites in Eu8Ga16Ge30, a stoichiometric clathrate. Remarkably, six of the eight europium atoms, or 11% of the constituents in this solid, tunnel between these four sites separated by 0.55 Å. The off centering of the atoms or ions in crystalline clathrates appears to be a promising route for producing Rabi oscillators in solid-state materials.

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Genetic Code Based Coding And Mathematical Formulation For Dna Computation, Mingjun Zhang, Maggie Xiaoyan Cheng, Tzyh-Jong Tarn Jun 2006

Genetic Code Based Coding And Mathematical Formulation For Dna Computation, Mingjun Zhang, Maggie Xiaoyan Cheng, Tzyh-Jong Tarn

Computer Science Faculty Research & Creative Works

DNA computation is to use DNA molecules for information storing and processing. Challenges currently faced by DNA computation are (1) lack of theoretical computational models for applications, and (2) high error rate for implementation. This paper attempts to address these problems from genetic coding and mathematical modeling aspects. The proposed genetic coding approach provides a promising alternative to reduce high error rate. The mathematical formulation lays down groundwork for studying theoretical aspects of DNA computation.

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Adaptive Neural Network Control And Wireless Sensor Network Based Localization For Uav Formation, H. Wu, Jagannathan Sarangapani Jun 2006

Adaptive Neural Network Control And Wireless Sensor Network Based Localization For Uav Formation, H. Wu, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

We consider a team of unmanned aerial vehicles (UAV's) equipped with sensors and motes for wireless communication for the task of navigating to a desired location in a formation. First a neural network (NN)-based control scheme is presented that allows the UAVs to track a desired position and orientation with reference to the neighboring UAVs or obstacles in the environment. Second, we discuss a graph theory-based scheme for discovery, localization and cooperative control. The purpose of the NN cooperative controller is to achieve and maintain the desired formation shape in the presence of unmodeled dynamics and bounded unknown disturbances. Numerical …

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Young-Type Interference In (E, 2e) Ionization Of H₂, D. S. Milne-Brownlie, Matthew S. Foster, Junfang Gao, B. Lohmann, Don H. Madison Jun 2006

Young-Type Interference In (E, 2e) Ionization Of H₂, D. S. Milne-Brownlie, Matthew S. Foster, Junfang Gao, B. Lohmann, Don H. Madison

Physics Faculty Research & Creative Works

We have investigated the electron impact single ionization of the hydrogen molecule, with fully determined kinematics. The experimental and theoretical results are compared with He ionization under the same conditions. The results indicate that the ejected electron angular distribution for H2 is modified due to Young-type interference between ionization amplitudes for scattering from the two centers in the hydrogen molecule. The observable result is a suppression of the backward scattering (recoil) peak compared with the binary peak.

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Quantum Electrodynamic Corrections To The Hyperfine Structure Of Excited S States, Ulrich D. Jentschura, Vladimir A. Yerokhin Jun 2006

Quantum Electrodynamic Corrections To The Hyperfine Structure Of Excited S States, Ulrich D. Jentschura, Vladimir A. Yerokhin

Physics Faculty Research & Creative Works

State-dependent quantum electrodynamic corrections are evaluated for the hyperfine splitting of nS states for arbitrary principal quantum number n. The calculations comprise both the self-energy and the vacuum-polarization correction of order α(Zα) 2 EF and the recoil correction of order (Zα)2 (m/M) EF. Higher-order corrections are summarized and partly reevaluated as well. Accurate predictions for hydrogen hyperfine splitting intervals of nS states with n=2,...,8 are presented. The results obtained are important due to steady progress in hydrogen spectroscopy for transitions involving highly excited S states.

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