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Sub-Symbolic Re-Representation To Facilitate Learning Transfer, Dan A. Ventura Mar 2008

Sub-Symbolic Re-Representation To Facilitate Learning Transfer, Dan A. Ventura

Faculty Publications

We consider the issue of knowledge (re-)representation in the context of learning transfer and present a subsymbolic approach for effecting such transfer. Given a set of data, manifold learning is used to automatically organize the data into one or more representational transformations, which are then learned with a set of neural networks. The result is a set of neural filters that can be applied to new data as re-representation operators. Encouraging preliminary empirical results elucidate the approach and demonstrate its feasibility, suggesting possible implications for the broader field of creativity.


Capacity Of The Continuous-Space Electromagnetic Channel, Michael A. Jensen, Jon W. Wallace Mar 2008

Capacity Of The Continuous-Space Electromagnetic Channel, Michael A. Jensen, Jon W. Wallace

Faculty Publications

Constructing the capacity bound of a multiple-input multiple-output wireless system is often performed by assuming specified antenna configurations and a propagation environment and determining the signaling strategy which maximizes throughput. This paper extends this approach to further determine the optimal antenna characteristics which maximize the capacity for the propagation scenario, with the resulting capacity bound representing the ultimate maximum achievable value if optimal antenna design and signaling are used. In this approach, the spatially-continuous transmit currents and receive fields are represented using eigenfunctions of appropriate operators. It is shown that, except under certain conditions where array supergain solutions emerge, the …


Experimental Analysis Of A Wideband Adaptive-Mimo Antenna, Michael A. Jensen Mar 2008

Experimental Analysis Of A Wideband Adaptive-Mimo Antenna, Michael A. Jensen

Faculty Publications

An experimental measurement campaign to investigate the wideband performance of an adaptive multiple-input multiple-output (AdaM) antenna consisting of two active and six parasitic antenna elements. The measurements are conducted over a 30 MHz bandwidth at a center frequency of 2.55 GHz and in a variety of locations in an indoor environment. The system uses a traditional two-element array at the transmitter and either a two-element traditional array or the AdaM antenna at the receiver. The results show that compared to the traditional array, the AdaM receive antenna can achieve the same throughput with an average power reduction of 2.7 dB …


Conformation Of A Coarse-Grained Protein Chain (An Aspartic Acid Protease) Model In Effective Solvent By A Bond-Fluctuating Monte Carlo Simulation, Ras B. Pandey, B.L. Farmer Mar 2008

Conformation Of A Coarse-Grained Protein Chain (An Aspartic Acid Protease) Model In Effective Solvent By A Bond-Fluctuating Monte Carlo Simulation, Ras B. Pandey, B.L. Farmer

Faculty Publications

In a coarse-grained description of a protein chain, all of the 20 amino acid residues can be broadly divided into three groups: Hydrophobic (H), polar (P), and electrostatic (E). A protein can be described by nodes tethered in a chain with a node representing an amino acid group. Aspartic acid protease consists of 99 residues in a well-defined sequence of H, P, and E nodes tethered together by fluctuating bonds. The protein chain is placed on a cubic lattice where empty lattice sites constitute an effective solvent medium. The amino groups (nodes) interact with the solvent (S) sites with appropriate …


Peer Review In An Undergraduate Biology Curriculum: Effects On Students’ Scientific Reasoning, Writing And Attitudes, Briana Eileen Timmerman Mar 2008

Peer Review In An Undergraduate Biology Curriculum: Effects On Students’ Scientific Reasoning, Writing And Attitudes, Briana Eileen Timmerman

Faculty Publications

Scientific reasoning and writing skills are ubiquitous processes in science and therefore common goals of science curricula, particularly in higher education. Providing the individualized feedback necessary for the development of these skills is often costly in terms of faculty time, particularly in large science courses common at research universities. Past educational research literature suggests that the use of peer review may accelerate students’ scientific reasoning skills without a concurrent demand on faculty time per student. Peer review contains many elements of effective pedagogy such as peer-peer collaboration, repeated practice at evaluation and critical thinking, formative feedback, multiple contrasting examples, and …


Ant Clustering With Locally Weighting Ant Perception And Diversified Memory, Gilbert L. Peterson, Christopher B. Mayer, Thomas L. Kubler Mar 2008

Ant Clustering With Locally Weighting Ant Perception And Diversified Memory, Gilbert L. Peterson, Christopher B. Mayer, Thomas L. Kubler

Faculty Publications

Ant clustering algorithms are a robust and flexible tool for clustering data that have produced some promising results. This paper introduces two improvements that can be incorporated into any ant clustering algorithm: kernel function similarity weights and a similarity memory model replacement scheme. A kernel function weights objects within an ant’s neighborhood according to the object distance and provides an alternate interpretation of the similarity of objects in an ant’s neighborhood. Ants can hill-climb the kernel gradients as they look for a suitable place to drop a carried object. The similarity memory model equips ants with a small memory consisting …


The Importance Of Generalizability To Anomaly Detection, Gilbert L. Peterson, Brent T. Mcbride Mar 2008

The Importance Of Generalizability To Anomaly Detection, Gilbert L. Peterson, Brent T. Mcbride

Faculty Publications

In security-related areas there is concern over novel “zero-day” attacks that penetrate system defenses and wreak havoc. The best methods for countering these threats are recognizing “nonself” as in an Artificial Immune System or recognizing “self” through clustering. For either case, the concern remains that something that appears similar to self could be missed. Given this situation, one could incorrectly assume that a preference for a tighter fit to self over generalizability is important for false positive reduction in this type of learning problem. This article confirms that in anomaly detection as in other forms of classification a tight fit, …


Multi-Class Classification Fusion Using Boosting For Identifying Steganography Methods, Benjamin M. Rodriguez, Gilbert L. Peterson Mar 2008

Multi-Class Classification Fusion Using Boosting For Identifying Steganography Methods, Benjamin M. Rodriguez, Gilbert L. Peterson

Faculty Publications

No abstract provided.


Clouds Search For Variability In Brown Dwarf Atmospheres: Infrared Spectroscopic Time Series Of L/T Transition Brown Dwarfs, D. Stephens, B. Goldman, M. C. Cushing, M. S. Marley, E. Artigau, K. S. Baliyan, V. J. S. Bejar, J. A. Caballero, N. Chanover, M. Connelley, R. Doyon, T. Forveille, S. Ganesh, C. R. Gelino, H. B. Hammel, J. Holtzman, S. Joshi, U. C. Joshi, S. K. Leggett, M. C. Liu Feb 2008

Clouds Search For Variability In Brown Dwarf Atmospheres: Infrared Spectroscopic Time Series Of L/T Transition Brown Dwarfs, D. Stephens, B. Goldman, M. C. Cushing, M. S. Marley, E. Artigau, K. S. Baliyan, V. J. S. Bejar, J. A. Caballero, N. Chanover, M. Connelley, R. Doyon, T. Forveille, S. Ganesh, C. R. Gelino, H. B. Hammel, J. Holtzman, S. Joshi, U. C. Joshi, S. K. Leggett, M. C. Liu

Faculty Publications

L-type ultra-cool dwarfs and brown dwarfs have cloudy atmospheres that could host weather-like phenomena. The detection of photometric or spectral variability would provide insight into unresolved atmospheric heterogeneities, such as holes in a global cloud deck. Indeed, a number of ultra-cool dwarfs have been reported to vary. Additional time-resolved spectral observations of brown dwarfs offer the opportunity for further constraining and characterising atmospheric variability. Aims. It has been proposed that growth of heterogeneities in the global cloud deck may account for the L- to T-type transition when brown dwarf photospheres evolve from cloudy to clear conditions. Such a mechanism is …


Below- And Aboveground Biomass Of Spartina Alterniflora: Response To Nutrient Addition In A Louisiana Salt Marsh, Faith A. Darby, R. Eugene Turner Feb 2008

Below- And Aboveground Biomass Of Spartina Alterniflora: Response To Nutrient Addition In A Louisiana Salt Marsh, Faith A. Darby, R. Eugene Turner

Faculty Publications

The responses of Spartina alterniflora above- and belowground biomass to various combinations of N, P, and Fe were documented in a 1-year field experiment in a Louisiana salt marsh. Five levels of N additions to 0.25 m2 plots resulted in 18% to 138% more live aboveground biomass compared to the control plots and higher stem densities, but had no effect on the amount of live belowground biomass (roots and rhizomes; R&R). There was no change in the aboveground biomass when P or Fe was added as part of a factorial experiment of +P, +N, and +Fe additions, but there was …


Observations Of Piezoresistivity For Polysilicon In Bending That Are Unexplained By Linear Models, Tyler L. Waterfall, Gary K. Johns, Robert K. Messenger, Brian D. Jensen, Timothy W. Mclain, Larry L. Howell Feb 2008

Observations Of Piezoresistivity For Polysilicon In Bending That Are Unexplained By Linear Models, Tyler L. Waterfall, Gary K. Johns, Robert K. Messenger, Brian D. Jensen, Timothy W. Mclain, Larry L. Howell

Faculty Publications

Compliant piezoresistive MEMS sensors exhibit great promise for improved on-chip sensing. As compliant sensors may experience complex loads, their design and implementation require a greater understanding of the piezoresistive effect of polysilicon in bending and combined loads. This paper presents experimental results showing the piezoresistive effect for these complex loads. Several n-type polysilicon test structures, fabricated in MUMPs and SUMMiT processes, were tested. Results show that, while tensile stresses cause a linear decrease in resistance, bending stresses induce a nonlinear rise in resistance, contrary to the effect predicted by linear models. In addition, tensile, compressive, and bending loads combine in …


Current-Voltage Characteristics Of Semiconductor/Ferromagnet Junctions In The Spin-Blockade Regime, Yuriy V. Pershin Dr, Massimiliano Di Ventra Feb 2008

Current-Voltage Characteristics Of Semiconductor/Ferromagnet Junctions In The Spin-Blockade Regime, Yuriy V. Pershin Dr, Massimiliano Di Ventra

Faculty Publications

It was recently predicted [Phys. Rev. B, 193301 (2007)] that spin blockade may develop at nonmagnetic semiconductor/perfect ferromagnet junctions when the electron flow is directed from the semiconductor into the ferromagnet. Here we consider current-voltage characteristics of such junctions. By taking into account the contact resistance, we demonstrate a current stabilization effect: by increasing the applied voltage, the current density through the junction saturates at a specific value. The transient behavior of the current density is also investigated. We show that an abrupt change in the applied voltage is accompanied by a spike in the current density. It is anticipated …


A Precise Measurement Of The Muon Neutrino–Nucleon Inclusive Charged Current Cross Section Off An Isoscalar Target In The Energy Range 2.5 < EV < 40 Gev By Nomad, Nomad Collaboration, Q. Wu, S. R. Mishra, A. Godley, Roberto Petti, S. Alekhin, P. Astier, D. Autiero, A. Baldisseri, M. Baldo-Ceolin, M. Banner, G. Bassompierre, K. Benslama, N. Besson, I. Bird, B. Blumenfeld, F. Bobisut, J. Bouchez, S. Boyd, A. Bueno, Et. Al. Feb 2008

A Precise Measurement Of The Muon Neutrino–Nucleon Inclusive Charged Current Cross Section Off An Isoscalar Target In The Energy Range 2.5 < EV < 40 Gev By Nomad, Nomad Collaboration, Q. Wu, S. R. Mishra, A. Godley, Roberto Petti, S. Alekhin, P. Astier, D. Autiero, A. Baldisseri, M. Baldo-Ceolin, M. Banner, G. Bassompierre, K. Benslama, N. Besson, I. Bird, B. Blumenfeld, F. Bobisut, J. Bouchez, S. Boyd, A. Bueno, Et. Al.

Faculty Publications

We present a measurement of the muon neutrino–nucleon inclusive charged current cross section, off an isoscalar target, in the neutrino energy range 2.5⩽Ev ⩽ 40GeV. The significance of this measurement is its precision, ±4% in 2.5⩽Ev ⩽ 10GeV, and ± 2.6% in 10⩽Ev ⩽ 40GeV regions, where significant uncertainties in previous experiments still exist, and its importance to the current and proposed long baseline neutrino oscillation experiments.


Quenching Of Highly Vibrationally Excited Pyrimidine By Collisions With Co4, Jeremy A. Johnson, Andrew M. Duffin, Brian J. Hom, Karl E. Jackson, Eric T. Sevy Feb 2008

Quenching Of Highly Vibrationally Excited Pyrimidine By Collisions With Co4, Jeremy A. Johnson, Andrew M. Duffin, Brian J. Hom, Karl E. Jackson, Eric T. Sevy

Faculty Publications

Relaxation of highly vibrationally excited pyrimidine (C4N2H4) by collisions with carbon dioxide has been investigated using diode laser transient absorption spectroscopy. Vibrationally hot pyrimidine (E'=40,635 cm^-1) was prepared by 248-nm excimer laser excitation, followed by rapid radiationless relaxation to the ground electronic state. The nascent rotational population distribution (J=58–80) of the 0000 ground state of CO2 resulting from collisions with hot pyrimidine was probed at short times following the excimer laser pulse. Doppler spectroscopy was used to measure the CO2 recoil velocity distribution for J=58–80 of the 0000 state. Rate constants and probabilities for collisions populating these CO2 rotational states …


Ozone Exposure In A Mouse Model Induces Airway Hyperreactivity That Requires The Presence Of Natural Killer T Cells And Il-17, Paul B. Savage, Muriel Pichavant, Sho Goya, Everett H. Meyer, Richard A. Johnston, Hye Y. Kim, Ponpan Matangkasombut, Ming Zhu, Yoichiro Iwakura, Rosemarie H. Dekruyff, Stephanie A. Shore, Dale T. Umetsu Feb 2008

Ozone Exposure In A Mouse Model Induces Airway Hyperreactivity That Requires The Presence Of Natural Killer T Cells And Il-17, Paul B. Savage, Muriel Pichavant, Sho Goya, Everett H. Meyer, Richard A. Johnston, Hye Y. Kim, Ponpan Matangkasombut, Ming Zhu, Yoichiro Iwakura, Rosemarie H. Dekruyff, Stephanie A. Shore, Dale T. Umetsu

Faculty Publications

Exposure to ozone, which is a major component of air pollution, induces a form of asthma that occurs in the absence of adaptive immunity. Although ozone-induced asthma is characterized by airway neutrophilia, and not eosinophilia, it is nevertheless associated with airway hyperreactivity (AHR), which is a cardinal feature of asthma. Because AHR induced by allergens requires the presence of natural killer T (NKT) cells, we asked whether ozone-induced AHR had similar requirements. We found that repeated exposure of wild-type (WT) mice to ozone induced severe AHR associated with an increase in airway NKT cells, neutrophils, and macrophages. Surprisingly, NKT cell-deficient …


Mathematics Library News 3, Aaron Lercher Feb 2008

Mathematics Library News 3, Aaron Lercher

Faculty Publications

No abstract provided.


On Atkin And Swinnerton-Dyer Congruence Relations (2), A. O.L. Atkin, Wen Ching Winnie Li, Ling Long Feb 2008

On Atkin And Swinnerton-Dyer Congruence Relations (2), A. O.L. Atkin, Wen Ching Winnie Li, Ling Long

Faculty Publications

In this paper we give an example of a noncongruence subgroup whose three-dimensional space of cusp forms of weight 3 has the following properties. For each of the four residue classes of odd primes modulo 8 there is a basis whose Fourier coefficients at infinity satisfy a three-term Atkin and Swinnerton-Dyer congruence relation, which is the p-adic analogue of the three-term recursion satisfied by the coefficients of classical Hecke eigenforms. We also show that there is an automorphic L-function over mathbb{Q} whose local factors agree with those of the l-adic Scholl representations attached to the space of noncongruence cusp forms. …


Stokes Antenna Temperatures, David G. Long, Jeffrey R. Piepmeier, Eni G. Njoku Feb 2008

Stokes Antenna Temperatures, David G. Long, Jeffrey R. Piepmeier, Eni G. Njoku

Faculty Publications

The growing importance of polarimetric radiometers has led to the need for a detailed theory for Stokes antenna temperatures. In this paper, we provide a full Stokes vector formulation of an antenna temperature that accounts for the entire antenna pattern, which includes polarization mixing in the main-beam and sidelobe effects. To derive the Stokes antenna temperatures, we follow the conventional methods in the Earth remote sensing literature while relying on a coherency algebra approach from radio astronomy. Connections and parallels to the conventional approaches are noted along the way. We also introduce generalizations of beam efficiency and cross polarization for …


A Systematic Approach For Securing Our Space Assets, Heather Yates, Michael R. Grimaila Feb 2008

A Systematic Approach For Securing Our Space Assets, Heather Yates, Michael R. Grimaila

Faculty Publications

We are surrounded by the use of space assets, but for the most part are unaware of their impact on our lives. On a daily basis, space assets contribute to our well-being and others around the world. Space activities have enhanced security, monitored the environment, improved and increased information growth and flow, created economic growth, and changed the way people around the world live and work.[1] Since the 1991 Gulf War, we have also come to understand how much the US military depends on space. Military forces use satellite information for communications, intelligence, surveillance, reconnaissance, warning, weather, navigation, and timing. …


Using Plsi-U To Detect Insider Threats By Datamining Email, James S. Okolica, Gilbert L. Peterson, Robert F. Mills Feb 2008

Using Plsi-U To Detect Insider Threats By Datamining Email, James S. Okolica, Gilbert L. Peterson, Robert F. Mills

Faculty Publications

Despite a technology bias that focuses on external electronic threats, insiders pose the greatest threat to an organisation. This paper discusses an approach to assist investigators in identifying potential insider threats. We discern employees' interests from e-mail using an extended version of PLSI. These interests are transformed into implicit and explicit social network graphs, which are used to locate potential insiders by identifying individuals who feel alienated from the organisation or have a hidden interest in a sensitive topic. By applying this technique to the Enron e-mail corpus, a small number of employees appear as potential insider threats.


Open Educational Resources: Enabling Universal Education, David Wiley, Tom Caswell, Shelley Henson, Marion Jensen Feb 2008

Open Educational Resources: Enabling Universal Education, David Wiley, Tom Caswell, Shelley Henson, Marion Jensen

Faculty Publications

The role of distance education is shifting. Traditionally distance education was limited in the number of people served because of production, reproduction, and distribution costs. Today, while it still costs the university time and money to produce a course, technology has made it such that reproduction costs are almost non-existent. This shift has significant implications, and allows distance educators to play an important role in the fulfillment of the promise of the right to universal education. At little or no cost, universities can make their content available to millions. This content has the potential to substantially improve the quality of …


Robustness Of Key Features Of Loop Quantum Cosmology, Abhay Ashtekar, Alejandro Corichi, Parampreet Singh Jan 2008

Robustness Of Key Features Of Loop Quantum Cosmology, Abhay Ashtekar, Alejandro Corichi, Parampreet Singh

Faculty Publications

A small simplification based on well-motivated approximations is shown to make loop quantum cosmology of the k=0 Friedman-Robertson-Walker model (with a massless scalar field) exactly soluble. Analytical methods are then used i) to show that the quantum bounce is generic; ii) to establish that the matter density has an absolute upper bound which, furthermore, equals the critical density that first emerged in numerical simulations and effective equations; iii) to bring out the precise sense in which the Wheeler-DeWitt theory approximates loop quantum cosmology and the sense in which this approximation fails; and iv) to show that discreteness underlying loop quantum …


Expanded Mathematical Treatment For "Spectral Bias In Adaptive Beamforming With Narrowband Interference'', Brian D. Jeffs, Karl F. Warnick Jan 2008

Expanded Mathematical Treatment For "Spectral Bias In Adaptive Beamforming With Narrowband Interference'', Brian D. Jeffs, Karl F. Warnick

Faculty Publications

This technical note presents extended versions of some mathematical derivations found in the paper Spectral Bias in Adaptive Beamforming with Narrowband Interference which is under review for publication in IEEE Signal Processing Letters. Though the SP Letters paper is self contained and complete, this note provides intermediate steps for some of the equation derivations to assist the interested readers who would like to re-create the results.


Oligocene Deep Water Export From The North Atlantic And The Development Of The Antarctic Circumpolar Current Examined With Neodymium Isotopes, Howie Scher, Ellen E. Martin Jan 2008

Oligocene Deep Water Export From The North Atlantic And The Development Of The Antarctic Circumpolar Current Examined With Neodymium Isotopes, Howie Scher, Ellen E. Martin

Faculty Publications

Neodymium (Nd) isotopes were measured on 181 samples of fossil fish teeth recovered from Oligocene toMiocene sections at Ocean Drilling Program Site 1090 (3700 m water depth) on Agulhas Ridge in the Atlanticsector of the Southern Ocean. A long-term decreasing trend toward less radiogenic Nd isotope compositionsdominates the record. This trend is interrupted by shifts toward more radiogenic compositions near the early/lateOligocene boundary and the Oligocene/Miocene boundary. Overall, eNd values at Agulhas Ridge are moreradiogenic than at other Atlantic locations, and are similar to those at Indian Ocean locations. The pattern ofvariability is remarkably similar to Nd isotope results from …


All-Sky Search For Periodic Gravitational Waves In Ligo S4 Data, B. Abbott, R. Abbott, R. Adhikari, J. Agresti, P. Ajith, B. Allen, R. Amin, S. B. Anderson, W. G. Anderson, M. Arain, M. Araya, H. Armandula, M. Ashley, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, K. Bayer, K. Belczynski, J. Betzwieser, P. T. Beyersdorf, B. Bhawal, I. A. Bilenko, Tiffany Z. Summerscales Jan 2008

All-Sky Search For Periodic Gravitational Waves In Ligo S4 Data, B. Abbott, R. Abbott, R. Adhikari, J. Agresti, P. Ajith, B. Allen, R. Amin, S. B. Anderson, W. G. Anderson, M. Arain, M. Araya, H. Armandula, M. Ashley, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, K. Bayer, K. Belczynski, J. Betzwieser, P. T. Beyersdorf, B. Bhawal, I. A. Bilenko, Tiffany Z. Summerscales

Faculty Publications

We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1000 Hz and with the frequency's time derivative in the range -1×10-8Hzs-1 to zero. Data from the fourth LIGO science run (S4) have been used in this search. Three different semicoherent methods of transforming and summing strain power from short Fourier transforms (SFTs) of the calibrated data have been used. The first, known as StackSlide, averages normalized power from each SFT. A "weighted Hough" scheme is also developed and used, which also allows for a multi-interferometer search. The third method, known as …


Attitude And Divergence In Business Students: An Examination Of Personality Differences In, Todd A. Brown Jan 2008

Attitude And Divergence In Business Students: An Examination Of Personality Differences In, Todd A. Brown

Faculty Publications

Many studies have reported that economics and business students have been more apt to act in self-interested ways when compared to their counterparts in other academic fields. It is our contention that past studies have not shed light on the underlying psychological differences which might be leading to this difference in behavior. We put forth evidence that certain business majors are correlated with a marked increase in levels of narcissism and decreased levels of empathy, as measured by psychological personality tests.


Watershed Forest Management Information System (Wfmis), Yanli Zhang, P. K. Barten Jan 2008

Watershed Forest Management Information System (Wfmis), Yanli Zhang, P. K. Barten

Faculty Publications

Maintenance of a sustainable clean water supply is critical for our future. However, watershed degradation is a common phenomenon around the world that leads to poor water quality. In order to protect water resources, the Watershed Forest Management Information System (WFMIS), was developed as an extension of ArcGIS® and is described in this paper. There are three submodels to address nonpoint source pollution mitigation, road system management, and silvicultural operations, respectively. The Watershed Management Priority Indices (WMPI) is a zoning approach to prioritize critical areas for conservation and restoration management. It meets the critical need to spatially differentiate land cover …


A Geowall With Physics And Astronomy Applications, Phillip Dukes, Dan Bruton Jan 2008

A Geowall With Physics And Astronomy Applications, Phillip Dukes, Dan Bruton

Faculty Publications

A GeoWall is a passive stereoscopic projection system that can be used by students, teachers, and researchers for visualization of the structure and dynamics of three-dimensional systems and data. The type of system described here adequately provides 3-D visualization in natural color for large or small groups of viewers. The name “GeoWall” derives from its initial development to visualize data in the geosciences.1 An early GeoWall system was developed by Paul Morin at the electronic visualization laboratory at the University of Minnesota and was applied in an introductory geology course in spring of 2001. Since that time, several stereoscopic media, …


Pid Parameter Optimization Of An Uav Longitudinal Flight Control System, Kamran Turkoglu, Ugur Ozdemir, Melike Nikbay, Elbrous Jafarov Jan 2008

Pid Parameter Optimization Of An Uav Longitudinal Flight Control System, Kamran Turkoglu, Ugur Ozdemir, Melike Nikbay, Elbrous Jafarov

Faculty Publications

In this paper, an automatic control system design based on Integral Squared Error (ISE) parameter optimization technique has been implemented on longitudinal flight dynamics of an UAV. It has been aimed to minimize the error function between the reference signal and the output of the plant. In the following parts, objective function has been defined with respect to error dynamics. An unconstrained optimization problem has been solved analytically by using necessary and sufficient conditions of optimality, optimum PID parameters have been obtained and implemented in control system dynamics.


The Dark Matter Halo Of Ngc 1399- Cdm Or Mond?, T. Richtler, Y. Schuberth, M. Hilker, B. Dirsch, L. Bassino, Aaron J. Romanowsky Jan 2008

The Dark Matter Halo Of Ngc 1399- Cdm Or Mond?, T. Richtler, Y. Schuberth, M. Hilker, B. Dirsch, L. Bassino, Aaron J. Romanowsky

Faculty Publications

Context. Central galaxies in galaxy clusters may be key discriminants in the competition between the cold dark matter (CDM) paradigm and modified Newtonian dynamics (MOND). Aims. We investigate the dark halo of NGC 1399, the central galaxy of the Fornax cluster, out to a galactocentric distance of 80 kpc. Methods.The data base consists of 656 radial velocities of globular clusters obtained with MXU/VLT and GMOS/Gemini, which is the largest sample so far for any galaxy. We performed a Jeans analysis for a non-rotating isotropic model. Results.An NFW halo with the parameters $r_{\rm s} = 50\,\rm {kpc}$ and $\varrho_{\rm s} = …