Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 62641 - 62670 of 294419

Full-Text Articles in Physical Sciences and Mathematics

How To Make Quantum Ideas Less Counter-Intuitive: A Simple Analysis Of Measurement Uncertainty Can Help, Olga Kosheleva, Vladik Kreinovich, Louis Ray Lopez Mar 2022

How To Make Quantum Ideas Less Counter-Intuitive: A Simple Analysis Of Measurement Uncertainty Can Help, Olga Kosheleva, Vladik Kreinovich, Louis Ray Lopez

Departmental Technical Reports (CS)

Our intuition about physics is based on macro-scale phenomena, phenomena which are well described by non-quantum physics. As a result, many quantum ideas sound counter-intuitive -- and this slows down students' learning of quantum physics. In this paper, we show that a simple analysis of measurement uncertainty can make many of the quantum ideas much less counter-intuitive and thus, much easier to accept and understand.


Physical Meaning Often Leads To Natural Derivations In Elementary Mathematics: On The Examples Of Solving Quadratic And Cubic Equations, Christian Servin, Olga Kosheleva, Vladik Kreinovich Mar 2022

Physical Meaning Often Leads To Natural Derivations In Elementary Mathematics: On The Examples Of Solving Quadratic And Cubic Equations, Christian Servin, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

Usual derivation of many formulas of elementary mathematics -- such as the formulas for solving quadratic equation -- often leave un unfortunate impression that mathematics is a collection of unrelated unnatural trick. In this paper, on the example of formulas for solving quadratic and cubic equations, we show that these derivations can be made much more natural if we take physical meaning into account.


Why Immunodepressive Drugs Often Make People Happier, Joshua Ramos, Dario Vasquez, Ruth Trejo, Vladik Kreinovich Mar 2022

Why Immunodepressive Drugs Often Make People Happier, Joshua Ramos, Dario Vasquez, Ruth Trejo, Vladik Kreinovich

Departmental Technical Reports (CS)

Many immunodepressive drugs have an unusual side effect on the patient's mood: they often make the patient happier. This side hae been observed for many different immunodepressive drugs, with different chemical composition. Thus, it is natural to conclude that there must be some general reason for this empirical phenomenon, a reason not related to the chemical composition of any specific drug -- but rather with their general functionality. In this paper, we provide such an explanation.


Explaining An Empirical Formula For Bioreaction To Similar Stimuli (Covid-19 And Beyond), Olga Kosheleva, Vladik Kreinovich, Nguyen Hoang Phuong Mar 2022

Explaining An Empirical Formula For Bioreaction To Similar Stimuli (Covid-19 And Beyond), Olga Kosheleva, Vladik Kreinovich, Nguyen Hoang Phuong

Departmental Technical Reports (CS)

A recent comparative analysis of biological reaction to unchanging vs. rapidly changing stimuli -- such as Covid-19 or flu viruses -- uses an empirical formula describing how the reaction to a similar stimulus depends on the distance between the new and original stimuli. In this paper, we provide a from-first-principles explanation for this empirical formula.


The International Pulsar Timing Array Second Data Release: Search For An Isotropic Gravitational Wave Background, J. Antoniadis, Z. Arzoumanian, S. Babak, M. Bailes, A.-S. Bak Nielsen, P. T. Baker, C. G. Bassa, B. Bécsy, A. Berthereau, M. Bonetti, A. Brazier, P. R. Brook, M. Burgay, S. Burke-Spolaor, R. N. Caballero, J. A. Casey-Clyde, A. Chalumeau, D. J. Champion, M. Charisi, S. Chatterjee, S. Chen, I. Cognard, J. M. Cordes, N. J. Cornish, F. Crawford, H. T. Cromartie, K. Crowter, S. Dai, M. E. Decesar, P. B. Demorest, G. Desvignes, T. Dolch, B. Drachler, M. Falxa, E. C. Ferrara, W. Fiore, E. Fonseca, J. R. Gair, N. Garver-Daniels, B. Goncharov, D. C. Good, E. Graikou, L. Guillemot, Y. J. Guo, J. S. Hazboun, G. Hobbs, H. Hu, K. Islo, G. H. Janssen, R. J. Jennings, A. D. Johnson, M. L. Jones, A. R. Kaiser, D. L. Kaplan, R. Karuppusamy, M. J. Keith, L. Z. Kelley, M. Kerr, J. S. Key, M. Kramer, M. T. Lam, W. G. Lamb, T. J. W. Lazio, K. J. Lee, L. Lentati, K. Liu, J. Luo, R. S. Lynch, A. G. Lyne, D. R. Madison, R. A. Main, R. N. Manchester, A. Mcewen, J. W. Mckee, M. A. Mclaughlin, M. B. Mickaliger, C. M. F. Mingarelli, C. Ng, D. J. Nice, S. Osłowski, A. Parthasarathy, T. T. Pennucci, B. B. P. Perera, D. Perrodin, A. Petiteau, N. S. Pol, N. K. Porayko, A. Possenti, S. M. Ransom, P. S. Ray, D. J. Reardon, C. J. Russell, S. Samajdar, L. M. Sampson, S. Sanidas, J. M. Sarkissian, K. Schmitz, L. Schult, A. Sesana, G. Shaifullah, R. M. Shannon, B. J. Shapiro-Albert, X. Siemens, J. Simon, Tristan L. Smith, L. Speri, R. Spiewak, I. H. Stairs, B. W. Stappers, D. R. Stinebring, J. K. Swiggum, S. R. Taylor, G. Theureau, C. Tiburzi, M. Vallisneri, E. Van Der Wateren, A. Vecchio, J. P. W. Verbiest, S. J. Vigeland, H. Wahl, J. B. Wang, J. Wang, L. Wang, C. A. Witt, S. Zhang, X. J. Zhu Mar 2022

The International Pulsar Timing Array Second Data Release: Search For An Isotropic Gravitational Wave Background, J. Antoniadis, Z. Arzoumanian, S. Babak, M. Bailes, A.-S. Bak Nielsen, P. T. Baker, C. G. Bassa, B. Bécsy, A. Berthereau, M. Bonetti, A. Brazier, P. R. Brook, M. Burgay, S. Burke-Spolaor, R. N. Caballero, J. A. Casey-Clyde, A. Chalumeau, D. J. Champion, M. Charisi, S. Chatterjee, S. Chen, I. Cognard, J. M. Cordes, N. J. Cornish, F. Crawford, H. T. Cromartie, K. Crowter, S. Dai, M. E. Decesar, P. B. Demorest, G. Desvignes, T. Dolch, B. Drachler, M. Falxa, E. C. Ferrara, W. Fiore, E. Fonseca, J. R. Gair, N. Garver-Daniels, B. Goncharov, D. C. Good, E. Graikou, L. Guillemot, Y. J. Guo, J. S. Hazboun, G. Hobbs, H. Hu, K. Islo, G. H. Janssen, R. J. Jennings, A. D. Johnson, M. L. Jones, A. R. Kaiser, D. L. Kaplan, R. Karuppusamy, M. J. Keith, L. Z. Kelley, M. Kerr, J. S. Key, M. Kramer, M. T. Lam, W. G. Lamb, T. J. W. Lazio, K. J. Lee, L. Lentati, K. Liu, J. Luo, R. S. Lynch, A. G. Lyne, D. R. Madison, R. A. Main, R. N. Manchester, A. Mcewen, J. W. Mckee, M. A. Mclaughlin, M. B. Mickaliger, C. M. F. Mingarelli, C. Ng, D. J. Nice, S. Osłowski, A. Parthasarathy, T. T. Pennucci, B. B. P. Perera, D. Perrodin, A. Petiteau, N. S. Pol, N. K. Porayko, A. Possenti, S. M. Ransom, P. S. Ray, D. J. Reardon, C. J. Russell, S. Samajdar, L. M. Sampson, S. Sanidas, J. M. Sarkissian, K. Schmitz, L. Schult, A. Sesana, G. Shaifullah, R. M. Shannon, B. J. Shapiro-Albert, X. Siemens, J. Simon, Tristan L. Smith, L. Speri, R. Spiewak, I. H. Stairs, B. W. Stappers, D. R. Stinebring, J. K. Swiggum, S. R. Taylor, G. Theureau, C. Tiburzi, M. Vallisneri, E. Van Der Wateren, A. Vecchio, J. P. W. Verbiest, S. J. Vigeland, H. Wahl, J. B. Wang, J. Wang, L. Wang, C. A. Witt, S. Zhang, X. J. Zhu

Physics & Astronomy Faculty Works

We searched for an isotropic stochastic gravitational wave background in the second data release of the International Pulsar Timing Array, a global collaboration synthesizing decadal-length pulsar-timing campaigns in North America, Europe, and Australia. In our reference search for a power-law strain spectrum of the form hc = A(f/1 yr⁻¹)α, we found strong evidence for a spectrally similar low-frequency stochastic process of amplitude A = 3.8 (+6.3)/(-2.5) × 10⁻¹⁵ and spectral index α = −0.5 ± 0.5, where the uncertainties represent 95 per cent credible regions, using information from the auto- and cross-correlation terms between …


Autonomous, Long-Range, Sensor Emplacement Using Unmanned Aircraft Systems, Adam Plowcha, Justin Bradley, Jacob Hoberg, Thomas Ammon, Mark Nail, Brittany Duncan, Carrick Detweiler Mar 2022

Autonomous, Long-Range, Sensor Emplacement Using Unmanned Aircraft Systems, Adam Plowcha, Justin Bradley, Jacob Hoberg, Thomas Ammon, Mark Nail, Brittany Duncan, Carrick Detweiler

School of Computing: Faculty Publications

Automated, in-ground sensor emplacement can significantly improve remote, terrestrial, data collection capabilities. Utilizing a multicopter, unmanned aircraft system (UAS) for this purpose allows sensor insertion with minimal disturbance to the target site or surrounding area. However, developing an emplacement mechanism for a small multicopter, autonomy to manage the target selection and implantation process, as well as long-range deployment are challenging to address. We have developed an autonomous, multicopter UAS that can implant subsurface sensor devices. We enhanced the UAS autopilot with autonomy for target and landing zone selection, as well as ensuring the sensor is implanted properly in the ground. …


Peak Chlorophyll A Concentrations In The Lower Mississippi River From 1997 To 2018, R. Eugene Turner, Charles S. Milan, Erick M. Swenson, James M. Lee Mar 2022

Peak Chlorophyll A Concentrations In The Lower Mississippi River From 1997 To 2018, R. Eugene Turner, Charles S. Milan, Erick M. Swenson, James M. Lee

Faculty Publications

Large and turbid rivers have varying temperatures, light conditions, nutrient availability, and nutrient ratios that may affect phytoplankton communities and occur within a changing world of point and nonpoint source nutrient loadings. We investigated how these physical and chemical factors affect Chlorophyll a (Chl a) concentrations in the Mississippi River, the largest river in North America, by sampling 878 times from February 1997 to December 2018 near its terminus at Baton Rouge, Louisiana. We hypothesized that nutrient concentrations and ratios were significant factors limiting phytoplankton biomass accumulations in this turbid river. The Chl a concentrations were in the "poor" water …


The Coastal Monitor: Vol. 8 No. 4, John Tanacredi Ph.D. Mar 2022

The Coastal Monitor: Vol. 8 No. 4, John Tanacredi Ph.D.

The Coastal Monitor

The original five acre of land portion of the historic Blue Points Oyster Company is located at the southern end of Atlantic Ave in West Sayville, Islip Town, Suffolk County, New York on the shore of Great South Bay. The Center for Environmental Research and Coastal Oceans Monitoring (CERCOM) is the science field station serving Molloy College’s BCES programs in Earth & Environmental Sciences and Biology. Our mission is to provide unique hands-on educational opportunities in the physical and life sciences, in collaboration with a host of Federal, State, and local and NGO groups, to bolster students’ career path. Great …


Iowa Waste Reduction Center Newsletter, March 2022, University Of Northern Iowa. Iowa Waste Reduction Center. Mar 2022

Iowa Waste Reduction Center Newsletter, March 2022, University Of Northern Iowa. Iowa Waste Reduction Center.

Iowa Waste Reduction Center Newsletter

Contents:

--- Upcoming Events
--- Important Reminder about Student Health Insurance
--- UNI Hosts Cedar Valley Sustainability Business Workshops and Competition
--- Compost Operator Re-certification Training Course
--- Welcome, Molly!
--- International Compost Awareness Week
--- Minor Source Emissions Inventory Assistance
--- Industry News


Adaptive Output Tracking Of Distributed Parameter Systems, İhsan Berk Altiner, Mustafa Doğan, Janset Daşdemi̇r Mar 2022

Adaptive Output Tracking Of Distributed Parameter Systems, İhsan Berk Altiner, Mustafa Doğan, Janset Daşdemi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we consider the unknown trajectory tracking problem for stable distributed parameter systems. The main assumptions are that trajectory signals are generated by an unknown finite-dimensional exosystem that is a marginally stable system and the tracking error is available for measurement. In order to achieve perfect error regulation, a frequency estimator scheme is proposed to estimate unknown exosystem parameters, and the control law that is designed based on geometric output regulation theory is revisited. The success of the proposed method is demonstrated on a parabolic heat equation and a first-order hyperbolic partial differential equation.


Improving Adversarial Attacks Against Malconv, Justin Burr Mar 2022

Improving Adversarial Attacks Against Malconv, Justin Burr

Masters Theses & Doctoral Dissertations

This dissertation proposes several improvements to existing adversarial attacks against MalConv, a raw-byte malware classifier for Windows PE files. The included contributions greatly improve the success rates and performance of gradient-based file overlay attacks. All improvements are included in a new open-source attack utility called BitCamo.

Several new payload initialization strategies for use with gradient-based attacks are proposed and evaluated as potential replacements for the randomized initialization method used by current attacks. An algorithm for determining the optimal payload size is also proposed. The resulting improvements achieve a 100% evasion rate against eligible target executables using an average payload size …


Polymer Coated Urea Microplastics: Urban Landscape, C. J. Seely, B. T. Geary, B. G. Hopkins Mar 2022

Polymer Coated Urea Microplastics: Urban Landscape, C. J. Seely, B. T. Geary, B. G. Hopkins

Library/Life Sciences Undergraduate Poster Competition 2022

  • Polymer Coated Urea (PCU) is an effective fertilizer.
  • Microplastics, from a wide range of waste materials, pollute water bodies.
  • One potential source of microplastics are from PCU fertilizers if the coatings are transported overland into water bodies.
  • Various urban landscape systems vary in the potential for surface runoff.


Exploiting Non-Linear Scales In Galaxy–Galaxy Lensing And Galaxy Clustering: A Forecast For The Dark Energy Survey, Andrés N. Salcedo, David H. Weinberg, Hao-Yi Wu, Benjamin D. Wibking Mar 2022

Exploiting Non-Linear Scales In Galaxy–Galaxy Lensing And Galaxy Clustering: A Forecast For The Dark Energy Survey, Andrés N. Salcedo, David H. Weinberg, Hao-Yi Wu, Benjamin D. Wibking

Physics Faculty Publications and Presentations

No abstract provided.


Kemar Hats Head Orientation Directivity, Samuel D. Bellows, Timothy W. Leishman Mar 2022

Kemar Hats Head Orientation Directivity, Samuel D. Bellows, Timothy W. Leishman

Directivity

This directivity data set for a KEMAR head head-and-torso simulator (HATS) includes head orientations in 14 directions in 5° steps starting from 0° to 40° and then in 10° steps from 40° to 90°. The full spherical measurements followed at an a = 0.97 m radius with the mouth aperture at the spherical center. The sampling density and distribution followed the AES 5° dual-equiangular sampling standard, omitting the south pole (θ = 180°). Thus, each spherical directivity assessment included 36 polar-angle θ samples and 72 azimuthal-angle ϕ samples. The presented data include 22 1/3-octave bands, ranging from 80 Hz …


Chemical Thermodynamics—A Practical Wonderland, Rubin Battino, Trevor M. Letcher Mar 2022

Chemical Thermodynamics—A Practical Wonderland, Rubin Battino, Trevor M. Letcher

Chemistry Faculty Publications

Chemical thermodynamics is frequently thought of as being a hard subject and quite abstract. In fact, it is one of the most practical of subjects when you consider that the field of chemical engineering (responsible for endless useful applications) is effectively applied chemical thermodynamics. In this essay, examples of these applications are given, especially with respect to sustainability. The essay first considers the limits of thermodynamics and the constraints put on it in terms of the rigorous definitions of the principal function’s energy, entropy, and Gibbs energy.


Co-Seismic And Post-Seismic Deformation For The 1995 Colima–Jalisco And 2003 Tecoman Thrust Earthquakes, Mexico Subduction Zone, ́ From Modelling Of Gps Data, Beatriz Cosenza-Muralles, Charles Demets, O. Sanchez, Enrique Cabral-Cano, J. Stock, B. Márquez-Azúa, Robert Mccaffrey Mar 2022

Co-Seismic And Post-Seismic Deformation For The 1995 Colima–Jalisco And 2003 Tecoman Thrust Earthquakes, Mexico Subduction Zone, ́ From Modelling Of Gps Data, Beatriz Cosenza-Muralles, Charles Demets, O. Sanchez, Enrique Cabral-Cano, J. Stock, B. Márquez-Azúa, Robert Mccaffrey

Geology Faculty Publications and Presentations

We invert ∼25 yr of campaign and continuous Global Positioning System daily positions at 62 sites in southwestern Mexico to estimate co-seismic and post-seismic afterslip solutions for the 1995 Mw = 8.0 Colima–Jalisco and the 2003 Mw = 7.5 Tecomán earthquakes, and the long-term velocity of each GPS site. Estimates of the viscoelastic effects of both earthquakes from a 3-D model with an elastic crust and subducting slab, and linear Maxwell viscoelastic mantle are used to correct the GPS position time-series prior to our time-dependent inversions. The preferred model, which optimizes the fit to data from several years …


Uranium Isotopic Composition And Constraints On The Provenance Of The Qinghai-Tibet Plateau's Surface Dust, Xiaoyu Jiao, Zhiwen Dong, Eric J. R. Parteli, Janice Brahney, Ting Wei, Marcelli Augusto, Junsheng Nie, Jiawen Ren, Xiang Qin Mar 2022

Uranium Isotopic Composition And Constraints On The Provenance Of The Qinghai-Tibet Plateau's Surface Dust, Xiaoyu Jiao, Zhiwen Dong, Eric J. R. Parteli, Janice Brahney, Ting Wei, Marcelli Augusto, Junsheng Nie, Jiawen Ren, Xiang Qin

Watershed Sciences Faculty Publications

The production and emission of aeolian dust can provide key information on the contemporary and historical links between geological evolution and climate. Here we use 234U/238U isotope ratios and the uranium (U) comminution age method on samples collected from Qinghai-Tibet Plateau (TP) surface dust and glacier snowpack/cryoconites to determine the erosion and potential transport provenance of the dust, regardless of petrological origin. The spatial variation of the (234U/238U) isotope ratios of TP dust showed relatively high values in the Songpan-Ganzi-Hoh Xil, Himalayan and the Kunlun-Qaidam-Qilian terranes, while showing relatively low (234U/ …


Deception-Based Knowledge In Indigenous And Scientific Societies American Indian Tricksters And Experimental Research Designs, Yancey Orr, Raymond Orr Mar 2022

Deception-Based Knowledge In Indigenous And Scientific Societies American Indian Tricksters And Experimental Research Designs, Yancey Orr, Raymond Orr

Environmental Science and Policy: Faculty Publications

The emerging movement to decolonize the sciences, social sciences, and humanities has emphasized the differences between Indigenous and Western scientific ways of knowing. Paradoxically, emphasizing the difference between these systems has also been the principle undergirding modern science’s claim to being a uniquely valid means of knowledge creation. Yet as each approach focused solely on contrasting Indigenous and scientific ways of knowing, potential similarities between these knowledge systems may have been ignored. One such oversight is the use of deception by each system, which is central to experimental research designs in the social and psychological sciences, and in American Indian …


A Privacy-Preserving National Clinical Data Warehouse: Architecture And Analysis, Md Raihan Mia, Abu Sayed Md Latiful Hoque, Shahidul Islam Khan, Sheikh Iqbal Ahamed Mar 2022

A Privacy-Preserving National Clinical Data Warehouse: Architecture And Analysis, Md Raihan Mia, Abu Sayed Md Latiful Hoque, Shahidul Islam Khan, Sheikh Iqbal Ahamed

Computer Science Faculty Research and Publications

A centralized clinical data repository is essential for inspecting patients’ medical history, disease analysis, population-wide disease research, treatment decision support, and improving existing healthcare policies and services. Bangladesh, a rapidly developing country, poses several unusual challenges for developing such a centralized clinical data repository as the existing Electronic Health Records (EHR) are stored in unconnected, heterogeneous sources with no unique patient identifier and consistency. Data integration with secure record linkage, privacy preservation, quality control, and data standardization are the main challenges for developing a consistent and interoperable centralized clinical data repository. Based on the findings from our previous researches, we …


Light Curve Test Of Grb 200716c As A Gravitationally Lensed Echo, Oindabi Mukherjee, Robert J. Nemiroff Mar 2022

Light Curve Test Of Grb 200716c As A Gravitationally Lensed Echo, Oindabi Mukherjee, Robert J. Nemiroff

Michigan Tech Publications, Part 1

A gravitational lens can imprint distinct features on the light curve of a gamma-ray burst (GRB). Most prominently, when creating multiple images, the light curves for all images should be identical, within a scale factor in amplitude. For GRB images that are bright enough to have significant counts in multiple time bins, the similarity of the light curves can be assessed with a straightforward χ2 test. In response to a recent claim that the two pulses in GRB 200716C are lensed images of the same pulse, such a χ2 test was computed. The test indicated that the likelihood …


Physical Significance Of Noether Symmetries, Asghar Qadir, Ugur Camci Mar 2022

Physical Significance Of Noether Symmetries, Asghar Qadir, Ugur Camci

Arts & Sciences Faculty Publications

In this paper, we will trace the development of the use of symmetry in discussing the theory of motion initiated by Emmy Noether in 1918. Though it started with its use in classical mechanics, and has been heavily used in engineering applications of mechanics, it came into its own in relativity, and quantum theory and their applications in particle physics and field theory. It will be beyond the scope of this article to explain the quantum field theory applications in any detail, but the base for understanding it will be provided here. We will also go on to discuss an …


Delaunay Walk For Fast Nearest Neighbor: Accelerating Correspondence Matching For Icp, James D. Anderson, Ryan M. Raettig, Josh Larson, Scott L. Nykl, Clark N. Taylor, Thomas Wischgoll Mar 2022

Delaunay Walk For Fast Nearest Neighbor: Accelerating Correspondence Matching For Icp, James D. Anderson, Ryan M. Raettig, Josh Larson, Scott L. Nykl, Clark N. Taylor, Thomas Wischgoll

Computer Science and Engineering Faculty Publications

Point set registration algorithms such as Iterative Closest Point (ICP) are commonly utilized in time-constrained environments like robotics. Finding the nearest neighbor of a point in a reference 3D point set is a common operation in ICP and frequently consumes at least 90% of the computation time. We introduce a novel approach to performing the distance-based nearest neighbor step based on Delaunay triangulation. This greedy algorithm finds the nearest neighbor of a query point by traversing the edges of the Delaunay triangulation created from a reference 3D point set. Our work integrates the Delaunay traversal into the correspondences search of …


Computational Characterization Of Charge Transport Resiliency In Molecular Solids, Balaji Sesha Sarath Pokuri, Seab M. Ryno, Ramin Noruzi, Chad Risko, Baskar Ganapathysubramanian Mar 2022

Computational Characterization Of Charge Transport Resiliency In Molecular Solids, Balaji Sesha Sarath Pokuri, Seab M. Ryno, Ramin Noruzi, Chad Risko, Baskar Ganapathysubramanian

Chemistry Faculty Publications

Organic semiconductors have found utility in a diverse array of applications. A key property impacting device performance is the charge transport mobility of the molecular solids making up the active layer in these devices. There is increasing interest in accessing, quantifying, and understanding the resilience of charge transport mobility to thermal, mechanical, and chemical perturbations in molecular solids. Here, we integrate molecular simulations with graph characterization to quantify the resilience of charge transport. We consider all-atom simulations of the PTB7 system and build on earlier graph approaches to rapidly characterize the charge mobility of the PTB7 molecular simulations. We introduce …


90snet:, Seth Richard Mar 2022

90snet:, Seth Richard

Honors Capstones

No abstract provided.


Gaia Gral: Gaia Dr2 Gravitational Lens Systems. Vii. Xmm-Newton Observations Of Lensed Quasars, Thomas Connor, Daniel Stern, Alberto Krone-Martins, S. G. Djorgovski, Matthew J. Graham Mar 2022

Gaia Gral: Gaia Dr2 Gravitational Lens Systems. Vii. Xmm-Newton Observations Of Lensed Quasars, Thomas Connor, Daniel Stern, Alberto Krone-Martins, S. G. Djorgovski, Matthew J. Graham

Faculty Publications

We present XMM-Newton X-ray observations of nine confirmed lensed quasars at 1 less than or similar to z less than or similar to 3 identified by the Gaia Gravitational Lens program. Eight systems are strongly detected, with 0.3-8.0 keV fluxes F (0.3-8.0) greater than or similar to 5 x10(-14) erg cm(-2) s(-1). Modeling the X-ray spectra with an absorbed power law, we derive power-law photon indices and 2-10 keV luminosities for the eight detected quasars. In addition to presenting sample properties for larger quasar population studies and for use in planning for future caustic-crossing events, we also identify three quasars …


A Multiparameter Degeneracy In Microlensing Events With Extreme Finite Source Effects, Samson A. Johnson, Matthew T. Penny, B. Scott Gaudi Mar 2022

A Multiparameter Degeneracy In Microlensing Events With Extreme Finite Source Effects, Samson A. Johnson, Matthew T. Penny, B. Scott Gaudi

Faculty Publications

For microlenses with sufficiently low mass, the angular radius of the source star can be much larger than the angular Einstein ring radius of the lens. For such extreme finite source effect (EFSE) events, finite source effects dominate throughout the duration of the event. Here, we demonstrate and explore a continuous degeneracy between multiple parameters of such EFSE events. The first component in the degeneracy arises from the fact that the directly observable peak change of the flux depends on both the ratio of the angular source radius to the angular Einstein ring radius and the fraction of the baseline …


Microwave Hyperthermia Application With Bioimplant Single Slot Coaxial Antennadesign For Mouse Breast Cancer Treatment, Ahmet Ri̇fat Görgün, Cem Baytöre, Selçuk Çömlekçi̇, Mehmet İbrahi̇m Tuğlu, Adnan Kaya Mar 2022

Microwave Hyperthermia Application With Bioimplant Single Slot Coaxial Antennadesign For Mouse Breast Cancer Treatment, Ahmet Ri̇fat Görgün, Cem Baytöre, Selçuk Çömlekçi̇, Mehmet İbrahi̇m Tuğlu, Adnan Kaya

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a novel animal model for the breast cancer treatment which contains hyperthermia is proposed. For this main purpose a low cost, interstitial, bioimplant antenna by short ended single slot design is proposed to heat the cancerous tissues. Both the theoretical background of the proposed system and the simulation and measurement results of antenna design are presented. An artificial tissue phantom model has been created under laboratory conditions and then the utility of the proposed antenna has been tested on this model. Artificial tissues have been heated by 25W to (41-44 ? C) in a short time like …


Identification And Mitigation Of Non-Line-Of-Sight Path Effect Using Repeater Forhybrid Ultra-Wideband Positioning And Networking System, Gwo Chin Chung, Mohd. Aqmal Syafiq Kamarudin, It Ee Lee, Soo Fun Tan Mar 2022

Identification And Mitigation Of Non-Line-Of-Sight Path Effect Using Repeater Forhybrid Ultra-Wideband Positioning And Networking System, Gwo Chin Chung, Mohd. Aqmal Syafiq Kamarudin, It Ee Lee, Soo Fun Tan

Turkish Journal of Electrical Engineering and Computer Sciences

At least two decades ago, various applications have been proposed for the implementation of ultra-wideband (UWB) technology, but only a few of them are being realised such as radar detection, home networking, and indoor positioning. Although UWB positioning offers precise locality tracking, the accuracy of the estimation is greatly affected by the non-line-of-sight (NLOS) path effect. In this paper, we propose a hybrid indoor UWB positioning and networking system that utilises the existing repeater of the data network to eliminate the NLOS paths. A switching algorithm is written to identify the existence of NLOS paths based on received signal strength …


A Factor Graph Optimization Mapping Based On Normaldistributions Transform, Kedi Zhong, Yuansheng Liu, Jiansuo Yang, Ming Lu, Jun Zhang Mar 2022

A Factor Graph Optimization Mapping Based On Normaldistributions Transform, Kedi Zhong, Yuansheng Liu, Jiansuo Yang, Ming Lu, Jun Zhang

Turkish Journal of Electrical Engineering and Computer Sciences

This paper aims to achieve highly accurate mapping results and real time pose estimation of autonomous vehicle by using the normal distribution transform (NDT) algoritm. A factor graph optimization algorithm (FGO-NDT) is proposed to address the poor real-time performance and pose drift errors of the NDT algorithm. Smooth point cloud data are obtained by multisensor calibration and data preprocessing. NDT registration is then used for lidar odometry and feature matching. The global navigation satellite system (GNSS) data and loop detection results are added to the factor graph framework as the pose constraint factors to optimize the pose trajectory and eliminate …


Independent Closed Loop Control Of Di/Dt And Dv/Dt For High Power Igbts, Osman Tanriverdi̇, Deni̇z Yildirim Mar 2022

Independent Closed Loop Control Of Di/Dt And Dv/Dt For High Power Igbts, Osman Tanriverdi̇, Deni̇z Yildirim

Turkish Journal of Electrical Engineering and Computer Sciences

As the insulated gate bipolar transistor (IGBT) modules have their own specific characteristic switching forms, their turn-on and turn-off times are changed according to practical applications. For the conventional gate drives, gate resistors are used to adjust the turn-on and turn-off times which change switching losses that have a significant amount in total losses. Collector current rate of change, $di_{C}/ dt$ and collector-emitter rate of change, $dv_{CE}/ dt$ are dependent on each other and they affect operating parameters in high power converters. Relations between current and voltages during the switching transitions are given and effects of the changes in electrical …