Physical Sciences and Mathematics Commons^™

Gps Constraints On Deformation In Northern Central America From 1999 To 2017, Part 1 – Time-Dependent Modelling Of Large Regional Earthquakes And Their Post-Seismic Effects, A. Ellis, Charles Demets, P. Briole, Beatriz Cosenza, Omar Flores, Shannon Graham, Marco Guzmán-Speziale, Douglas Hernandez, Vladimir Kostoglodov, Peter Lafemina, Neal Lord, Cécile Lasserre, Hélène Lyon-Caen, Manuel Rodriguez Maradiaga, Robert Mccaffrey, Enrique Molina, Jeffrey Rivera, Robert Rogers, Alejandra Staller

Geology Faculty Publications and Presentations

We use continuous and campaign measurements from 215 GPS sites in northern Central America and southern Mexico to estimate coseismic and afterslip solutions for the 2009 Mw = 7.3 Swan Islands fault strike-slip earthquake and the 2012 Mw = 7.3 El Salvador and Mw = 7.4 Guatemala thrust-faulting earthquakes on the Middle America trench. Our simultaneous, time-dependent inversion of more than 350 000 daily GPS site positions gives the first jointly consistent estimates of the coseismic slips for all three earthquakes, their combined time-dependent post-seismic effects and secular station velocities corrected for both the coseismic and post-seismic deformation. Our geodetic …

Decadal Topographic Change In The Mcmurdo Dry Valleys Of Antarctica: Thermokarst Subsidence, Glacier Thinning, And Transfer Of Water Storage From The Cryosphere To The Hydrosphere, J. S. Levy, Andrew G. Fountain, M. K. Obryk, J. Telling, Craig Glennie, M. Gooseff, David J. Van Horn

Geology Faculty Publications and Presentations

Recent local-scale observations of glaciers, streams, and soil surfaces in the McMurdo Dry Valleys of Antarctica (MDV) have documented evidence for rapid ice loss, glacial thinning, and ground surface subsidence associated with melting of ground ice. To evaluate the extent,magnitude, and location of decadal-scale landscape change in the MDV, we collected airborne lidar elevation data in 2014–2015 and compared these data to a 2001–2002 airborne lidar campaign. This regional assessment of elevation change spans the recent acceleration of warming and melting observed by long-term meteorological and ecosystem response experiments, allowing us to assess the response of MDV surfaces to warming …

Gps Constraints On Deformation In Northern Central America From 1999 To 2017, Part 1 – Time-Dependent Modelling Of Large Regional Earthquakes And Their Post-Seismic Effects, A. Ellis, Charles Demets, P. Briole, Beatriz Cosenza, Omar Flores, Shannon E. Graham, Robert Mccaffrey, Multiple Additional Authors

Geology Faculty Publications and Presentations

We use continuous and campaign measurements from 215 GPS sites in northern Central America and southern Mexico to estimate coseismic and afterslip solutions for the 2009 M_w = 7.3 Swan Islands fault strike-slip earthquake and the 2012 M_w = 7.3 El Salvador and M_w = 7.4 Guatemala thrust-faulting earthquakes on the Middle America trench. Our simultaneous, time-dependent inversion of more than 350 000 daily GPS site positions gives the first jointly consistent estimates of the coseismic slips for all three earthquakes, their combined time-dependent post-seismic effects and secular station velocities corrected for both the coseismic and post-seismic …

Concessive Online/Offline Attribute Based Encryption With Cryptographic Reverse Firewalls: Secure And Efficient Fine-Grained Access Control On Corrupted Machines, Hui Ma, Rui Zhang, Guomin Yang, Zishuai Song, Shuzhou Sun, Yuting Xiao

Research Collection School Of Computing and Information Systems

Attribute based encryption (ABE) has potential to be applied in various cloud computing applications. However, the Snowden revelations show that powerful adversaries can corrupt users’ machines to compromise the security, and many implementations of provably secure encryption schemes may present undetectable vulnerabilities that can expose secret, e.g., the scheme still works properly even some backdoors have been stealthily engineered on users’ machines. Undoubtedly, ABE is also facing the above security threats. Recently, Mironov and Stephens-Davidowitz proposed cryptographic reverse firewall (CRF) to solve the problem. Unfortunately, no CRF-based protection for ABE has been proposed so far due to the complex system …

Transferring Time-Series Discrete Choice To Link-Based Route Choice In Space: Estimating Vehicle Type Preference Using Recursive Logit Model, Fabian Bastin, Yan Liu, Cinzia Cirillo, Tien Mai

Research Collection School Of Computing and Information Systems

This paper considers a sequential discrete choice problem in a time domain, formulated and solved as a route choice problem in a space domain. Starting from a dynamic specification of time-series discrete choices, we show how it is transferrable to link-based route choices that can be formulated by a finite path choice multinomial logit model. This study establishes that modeling sequential choices over time and in space are equivalent as long as the utility of the choice sequence is additive over the decision steps, the link-specific attributes are deterministic, and the decision process is Markovian. We employ the recursive logit …

Teaching Basic Programming To Pre-University Students Through Blended Learning Pedagogy: A Descriptive Study, Vandana Ramachandra Rao, Ngee Mok Heng

Research Collection School Of Computing and Information Systems

Students enrolling for undergraduate programmes in Singapore would have either finished their polytechnic diploma or completed Junior College (JC) studies. Most pre-university students coming through the JC pathway are not exposed to programming as computing is offered as a subject in a very few JCs. The authors of this paper conducted four runs of an introductory programing course between 2016 and 2017 for a research project funded by the Ministry of Education, Singapore. The project named “Let’s Code!” was intended to introduce fundamental programming concepts to students and guide them to consider taking a computer-science related degree for their university …

Diversity In Online Advertising: A Case Study Of 69 Brands On Social Media, Jisun An, Ingmar Weber

Research Collection School Of Computing and Information Systems

Lack of diversity in advertising is a long-standing problem. Despite growing cultural awareness and missed business opportunities, many minorities remain under- or inappropriately represented in advertising. Previous research has studied how people react to culturally embedded ads, but such work focused mostly on print media or television using lab experiments. In this work, we look at diversity in content posted by 69 U.S. brands on two social media platforms, Instagram and Facebook. Using face detection technology, we infer the gender, race, and age of both the faces in the ads and of the users engaging with ads. Using this dataset, …

Resonance Attacks On Load Frequency Control Of Smart Grids, Yongdong Wu, Zhuo Wei, Jian Weng, Xin Li, Robert H. Deng

Research Collection School Of Computing and Information Systems

Load frequency control (LFC) is widely employed to regulate power plants in modern power generation systems of smart grids. This paper presents a simple and yet powerful type of attacks, referred to as resonance attacks, on LFC power generation systems. Specifically, in a resonance attack, an adversary craftily modifies the input of a power plant according to a resonance source (e.g., rate of change of frequency) to produce a feedback on LFC power generation system, such that the state of the power plant quickly becomes instable. Extensive computer simulations on popular LFC power generation system models which consist of linear, …

Question-Guided Hybrid Convolution For Visual Question Answering, Peng Gao, Pan Lu, Hongsheng Li, Shuang Li, Yikang Li, Steven C. H. Hoi, Xiaogang Wang

Research Collection School Of Computing and Information Systems

In this paper, we propose a novel Question-Guided Hybrid Convolution (QGHC) network for Visual Question Answering (VQA). Most state-of-the-art VQA methods fuse the high-level textual and visual features from the neural network and abandon the visual spatial information when learning multi-modal features.To address these problems, question-guided kernels generated from the input question are designed to convolute with visual features for capturing the textual and visual relationship in the early stage. The question-guided convolution can tightly couple the textual and visual information but also introduce more parameters when learning kernels. We apply the group convolution, which consists of question-independent kernels and …

Blockchain Based Efficient And Robust Fair Payment For Outsourcing Services In Cloud Computing, Yinghui Zhang, Robert H. Deng, Ximeng Liu, Dong Zheng

Research Collection School Of Computing and Information Systems

As an attractive business model of cloud computing, outsourcing services usually involve online payment and security issues. The mutual distrust between users and outsourcing service providers may severely impede the wide adoption of cloud computing. Nevertheless, most existing payment solutions only consider a specific type of outsourcing service and rely on a trusted third-party to realize fairness. In this paper, in order to realize secure and fair payment of outsourcing services in general without relying on any third-party, trusted or not, we introduce BCPay, a blockchain based fair payment framework for outsourcing services in cloud computing. We first present the …

Are You On The Right Track? Learning Career Tracks For Job Movement Analysis, Meng-Fen Chiang, Ee-Peng Lim, Wang-Chien Lee, Yuan Tian, Chih-Chieh Hung

Research Collection School Of Computing and Information Systems

Career track represents a vertical career pathway, where one can gradually move up to take up higher job appointments when relevant skills are acquired. Understanding the propensity of career movements in an evolving job market can enable timely career guidance to job seekers and working professionals. To this end, we harvest career trajectories from online professional network (OPN). Our focus lies on obtaining a macro view on career movements at the track granularity. Specifically, we propose a semi-supervised career track labelling framework to automatically assign career tracks for large set of jobs. To contextually label jobs, we collect example jobs …

A Hybrid Model For Identity Obfuscation By Face Replacement, Qianru Sun, Ayush Tewari, Weipeng Xu, Mario Fritz, Christian Theobalt, Bernt Schiele

Research Collection School Of Computing and Information Systems

As more and more personal photos are shared and tagged in social media, avoiding privacy risks such as unintended recognition, becomes increasingly challenging. We propose a new hybrid approach to obfuscate identities in photos by head replacement. Our approach combines state of the art parametric face synthesis with latest advances in Generative Adversarial Networks (GAN) for data-driven image synthesis. On the one hand, the parametric part of our method gives us control over the facial parameters and allows for explicit manipulation of the identity. On the other hand, the data-driven aspects allow for adding fine details and overall realism as …

Welcome Message From The Dysdoc3 2018 Chairs, Martin P. Robillard, Andrian Marcus, Christoph Treude, Michele Lanza

Research Collection School Of Computing and Information Systems

Presents the introductory welcome message from the conference proceedings. May include the conference officers' congratulations to all involved with the conference event and publication of the proceedings record.

Impact Of Climate Change On The Transition Of Neanderthals To Modern Humans In Europe, Michael Staubwasser, Virgil Drăgușin, Bogdan P. Onac, Sergey Assonov, Vasile Ersek, Dirk L. Hoffman, Daniel Veres

School of Geosciences Faculty and Staff Publications

Two speleothem stable isotope records from East-Central Europe demonstrate that Greenland Stadial 12 (GS12) and GS10—at 44.3–43.3 and 40.8–40.2 ka—were prominent intervals of cold and arid conditions. GS12, GS11, and GS10 are coeval with a regional pattern of culturally (near-)sterile layers within Europe’s diachronous archeologic transition from Neanderthals to modern human Aurignacian. Sterile layers coeval with GS12 precede the Aurignacian throughout the middle and upper Danube region. In some records from the northern Iberian Peninsula, such layers are coeval with GS11 and separate the Châtelperronian from the Aurignacian. Sterile layers preceding the Aurignacian in the remaining Châtelperronian domain are coeval …

Marikina Flood Hazard Models Using Historical Data Of Water Level, Elvira P. De Lara-Tuprio, Evangeline P. Bautista, Reginaldo M. Marcelo, Ramil T. Bataller, Divino Angelo B. Esteban, Yvanne Paolo B. Yutuc

Mathematics Faculty Publications

In this paper, ten-year historical data of water levels recorded at Sto. Niño, Marikina station of MMDA-EFCOS were analysed and processed to determine the number of times per year (annual frequency) that critical levels of the Marikina River near the Sto. Niño station were reached and for how long (duration). Probability distributions for the annual frequency and duration were then fitted to the samples obtained. Monte Carlo simulation was applied in order to generate possible realizations of the random variables. Summary statistics were then obtained from the simulated values. Finally, backtesting using historical data of water levels after the period …

Tutte-Equivalent Matroids, Maria Margarita Rocha

Electronic Theses, Projects, and Dissertations

We begin by introducing matroids in the context of finite collections of vectors from a vector space over a specified field, where the notion of independence is linear independence. Then we will introduce the concept of a matroid invariant. Specifically, we will look at the Tutte polynomial, which is a well-defined two-variable invariant that can be used to determine differences and similarities between a collection of given matroids. The Tutte polynomial can tell us certain properties of a given matroid (such as the number of bases, independent sets, etc.) without the need to manually solve for them. Although the Tutte …

Characterization And Quantification Of Covalent Modification Of Proteins Using Mass Spectrometry, Pratikkumar N. Rathod

Dissertations, Theses, and Capstone Projects

Identification and characterization of various post-translational modifications of protein is a key to understanding many unknown cellular processes. In the last few decades, mass spectrometry has evolved as an essential and effective analytical tool for qualitative and quantitative analysis of proteins. In this research, we have developed a novel MALDI-MS² based quantification method for Desmosine and Isodesmosine, which served as cross-linking amino acids of elastin, in order to measure the elastin degradation in the body. This is the first quantification method that not only illustrates the potential of MALDI-Ion Trap MS², but also improvement over the current …

The Development Of Novel Platforms For The Imaging Of Cancer By Positron Emission Tomography, Brendon E. Cook

Dissertations, Theses, and Capstone Projects

The role of antibody-based imaging of cancer by positron emission tomography (PET) has expanded significantly in recent years and is poised to radically alter the way that cancer is diagnosed and treated. However, one hurdle that remains is the potentially harmful radiation dose that comes from these imaging agents, as the long circulation time of antibodies (days to weeks) necessitates the use of radionuclides with comparable physical half-lives (i.e. ⁸⁹Zr, ¹²⁴I, etc.). One particularly promising solution is the use of the inverse electron demand Diels-Alder (IEDDA) reaction between a 1,2,4,5-tetrazine (Tz) and a trans-cyclooctene (TCO) for pretargeting. …

Using Cogenerative Dialogue To Catalyse Change, Carol A. Woodburn-Mcdonald

Dissertations, Theses, and Capstone Projects

Cogenerative dialogue is an empowering pedagogical approach to advance research. In my study cogenerative dialogue and coteaching were employed in an algebra 1 class in an urban high school in New York City. Lessons were cotaught with students and were videotaped for further analysis. The findings suggest that cogens constitute an excellent avenue to catalyze change in an urban algebra class.

Enhancing 3d Visual Odometry With Single-Camera Stereo Omnidirectional Systems, Carlos A. Jaramillo

Dissertations, Theses, and Capstone Projects

We explore low-cost solutions for efficiently improving the 3D pose estimation problem of a single camera moving in an unfamiliar environment. The visual odometry (VO) task -- as it is called when using computer vision to estimate egomotion -- is of particular interest to mobile robots as well as humans with visual impairments. The payload capacity of small robots like micro-aerial vehicles (drones) requires the use of portable perception equipment, which is constrained by size, weight, energy consumption, and processing power. Using a single camera as the passive sensor for the VO task satisfies these requirements, and it motivates the …

Supercharged Models Of Intrinsically Disordered Proteins And Their Utility In Sensing, Peter J. Schnatz

Dissertations, Theses, and Capstone Projects

In this thesis I show that greatly increasing the magnitude of a protein’s net charge using surface supercharging transforms that protein into a ligand-gated or counterion-gated conformational molecular switch. To demonstrate this I first modified the designed helical bundle hemoprotein H4 using simple molecular modeling, creating a highly charged protein which both unfolds reversibly at low ionic strength and undergoes the ligand-induced folding transition commonly observed in signal transduction by intrinsically disordered proteins in biology. Due to the high surface charge density, ligand binding to this protein is allosterically activated by low concentrations of divalent cations and the polyamine spermine. …

Charge State Dynamics And Quantum Sensing With Defects In Diamond, Jacob D. Henshaw

Dissertations, Theses, and Capstone Projects

In recent years, defect centers in wide band gap semiconductors such as diamond, have received significant attention. Defects offer great utility as single photon emitters, nanoscale sensors, and quantum memories and registers for quantum computation. Critical to the utility of these defects, is their charge state.

In this dissertation, experiments surrounding the charge state dynamics and the carrier dynamics are performed and analyzed. Extensive studies of the ionization and recombination processes of defects in diamond, specifically, the Nitrogen Vacancy (NV) center, have been performed. Diffusion of ionized charge carriers has been imaged indirectly through the recapture of said carriers by …

Regulation Of Dissolved Arsenic Using Zero-Valent Iron With Gypsum And Sulfate Reducing Bacteria: Laboratory Microcosm And Column Studies, Ying Liu

Dissertations, Theses, and Capstone Projects

Bench scale microcosm incubation was first conducted in two stages to examine the removal of arsenic (As) by zero-valent iron (ZVI) in the presence of sulfate reducing bacteria, gypsum as well as organic substrates under anaerobic condition. About 98% of dissolved As was removed from solution within 20 days with concurrent decrease of dissolved sulfate and growth of bacterial population. Mineralogy analysis using SEM-EDS found the formation of iron sulfide and Fourier-transformed infrared (FTIR) spectroscopy analysis indicates that some As is associated with pyrite. The main iron corrosion product was found as ferrihydrite with traces of lepidocrocite. Sequential leaching shows …

List, Sample, And Count, Ali Assarpour

Dissertations, Theses, and Capstone Projects

Counting plays a fundamental role in many scientific fields including chemistry, physics, mathematics, and computer science. There are two approaches for counting, the first relies on analytical tools to drive closed form expression, while the second takes advantage of the combinatorial nature of the problem to construct an algorithm whose output is the number of structures. There are many algorithmic techniques for counting, they cover the explicit approach of counting by listing to the approximate approach of counting by sampling.

This thesis looks at counting three sets of objects. First, we consider a subclass of boolean functions that are monotone. …

Synthesis And Evaluation Of Densely-Functionalized Troponoids, Danielle R. Hirsch

Dissertations, Theses, and Capstone Projects

Herein, we document our efforts to expand the scope of troponoid synthetic methodology towards densely-substituted scaffolds. This body of work has focused primarily on an oxidopyrylium cycloaddition/ring-opening strategy for the synthesis and biochemical evaluation of troponoids for assistance in a variety of medicinal chemistry studies. In Chapter 1, we outline the use of this synthetic strategy in the profiling of a library of synthetic αHTs against an aminoglycoside antibiotic resistance enzyme known as aminoglycoside-2’’-O-nucleotidyltransferase [ANT(2’’)-Ia]. Enzymatic mechanistic insights have been gleaned from an assessment of troponoid/antibiotic synergistic potential. In particular, two synthetic constructs were identified as promising antibiotic adjuvant candidates, …

Private-Key Fully Homomorphic Encryption For Private Classification Of Medical Data, Alexander N. Wood

Dissertations, Theses, and Capstone Projects

A wealth of medical data is inaccessible to researchers and clinicians due to privacy restrictions such as HIPAA. Clinicians would benefit from access to predictive models for diagnosis, such as classification of tumors as malignant or benign, without compromising patients’ privacy. In addition, the medical institutions and companies who own these medical information systems wish to keep their models private when used by outside parties.

Fully homomorphic encryption (FHE) enables practical polynomial computation over encrypted data. This dissertation begins with coverage of speed and security improvements to existing private-key fully homomorphic encryption methods. Next this dissertation presents a protocol for …

Baryons And Interactions In Magnetic Fields, Amol Deshmukh

Dissertations, Theses, and Capstone Projects

The QCD external field problem allows one to probe the rich behavior of strongly interacting systems under external conditions, including the modification of hadron structure and interactions due to external electromagnetic fields. These dynamics, moreover, are likely relevant to describe the physics in the interiors of magnetars and in non-central heavy-ion collisions, for which large magnetic fields upwards of $10^{19}$ Gauss are conceivable. Additionally motivated by lattice QCD calculations in external fields, we study the behavior of single- and two-baryon (specifically, two-nucleon) systems in large magnetic fields. The dependence of single-baryon energies on magnetic fields is explored using chiral dynamics. …

Direct Experimental Evidence Of Toroidal Symmetry In A Lanthanide-Based Molecular Magnet, Qing Zhang

Dissertations, Theses, and Capstone Projects

Molecular magnets (MM) are finite clusters of identical exchange-coupled magnetic systems arranged within a crystalline array such that interactions between neighboring MMs are negligible. Their small size has proven them amenable test beds for the investigation of a wide range of fundamental quantum phenomena such as spin frustration quantum tunneling (QT) of magnetization and Neel vector quantum coherence and Berry phase interference.

Cases where MMs have been found to exhibit quantum wave-functions that evolve coherently are particularly interesting due to their potential for use in quantum information processing. Toroidal magnetic moments, a kind of MM, have fascinating properties that could …

Strong Equivalence And Conservative Extensions Hand In Hand For Arguing Correctness Of New Action Language C Formalization, Yuliya Lierler

Yuliya Lierler

The Periglacial Landscape Of Mars: Insight Into The 'Decameter-Scale Rimmed Depressions' In Utopia Planitia, Arya Bina

Electronic Thesis and Dissertation Repository

Currently, Mars appears to be in a ‘frozen’ and ‘dry’ state, with the clear majority of the planet’s surface maintaining year-round sub-zero temperatures. However, the discovery of features consistent with landforms found in periglacial environments on Earth, suggests a climate history for Mars that may have involved freeze and thaw cycles. Such landforms include hummocky, polygonised, scalloped, and pitted terrains, as well as ice-rich deposits and gullies, along the mid- to high-latitude bands, typically with no lower than 20o N/S. The detection of near-surface and surface ice via the Phoenix lander, excavation of ice via recent impact cratering activity as …