cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Hubble Space Telescope Snapshot Survey for Resolved Companions of Galactic Cepheids: Final Results
Creators: name: Evans, Nancy Remage
name: Guenther, H. Moritz
name: Bond, Howard E.
name: Schaefer, Gail H.
name: Mason, Brian D.
name: Karovska, Margarita
name: Tingle, Evan
name: Wolk, Scott
name: Engle, Scott
name: Guinan, Edward
name: Pillitteri, Ignazio
name: Proffitt, Charles
name: Kervella, Pierre
name: Gallenne, Alexandre
name: Anderson, Richard I.
name: Moe, Maxwell
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Cepheids in multiple systems provide information on the outcome of the formation of massive stars. They can also lead to exotic end-stage objects. This study concludes our survey of 70 galactic Cepheids using the {\it Hubble Space Telescope\} (\HST) Wide Field Camera~3 (WFC3) with images at two wavelengths to identify companions closer than $5\arcsec$. In the entire WFC3 survey we identify 16 probable companions for 13 Cepheids. The seven Cepheids having resolved candidate companions within $2"$ all have the surprising property of themselves being spectroscopic binaries (as compared with a 29\% incidence of spectroscopic binaries in the general Cepheid population). That is a strong suggestion that an inner binary is linked to the scenario of a third companion within a few hundred~AU\null. This characteristic is continued for more widely separated companions. Under a model where the outer companion is formed first, it is unlikely that it can anticipate a subsequent inner binary. Rather it is more likely that a triple system has undergone dynamical interaction, resulting in one star moving outward to its current location. {\it Chandra\} and {\it Gaia\} data as well as radial velocities and \HSTSTIS and {\it IUE\} spectra are used to derive properties of the components of the Cepheid systems. The colors of the companion candidates show a change in distribution at approximately 2000~AU separations, from a range including both hot and cool colors for closer companions, to only low-mass companions for wider separations.
description: Accepted by ApJ
Design, Fabrication and Characterization of Hetero-PN-junction Devices for Photovoltaic and Photodetection Applications
Creators: name: Gu, Yonglin
Publisher: name: Maryland Shared Open Access Repository
Year: 2008
Subjects: Engineering, Electronics and Electrical(0544)

description: The main objective of this dissertation's research was to develop single-photon detectors with high detection efficiencies for photodetection application, as well as solar cells with high conversion efficiencies and radiance resistance for photovoltaic space applications. Hetero-PN-junctions, which can provide unique material combinations, were utilized in order to accomplish these goals. One of research focuses is on the high efficient four-junction solar cells using AlAsSb, InP, InGaAsP and InGaAs materials for space applications. The temperature and radiation effect on these solar cells performance were discussed. The effect of cell structure on the radiation response was studied. We fabricated the 1.0 eV InGaAsP cell, which is critical for this four-junction solar cell. A heterojunction AlInAs/InP tunnel diode, which interconnects the cells, was designed, fabricated and tested with low zero-bias resistivity of 4.76×10-3 ? cm2 and high peak tunnel current of 147 A/cm2. Avalanche photodiodes (APDs) with the structure of a single-avalanche-stage were proposed to achieve high gain, high speed, and low noise operation for telecommunication applications. Simulation results show that it is possible to realize such a device with the InGaAs/InGaAlAs/InAlAs/InGaAsP/InGaAs materials system by combing the high doping with the heterojunction band discontinuity. Mesa-terminated N = 1 APDs were fabricated with the procedure developed using the equipment and facilities available at UMBC cleanroom. Multiplication gains were demonstrated at low bias voltages of ~ 7 V. The results show the dark current decreased a factor of 10 at a gain of 10 by changing the p-dopant from Zn to carbon. We believe that the high performance device can be obtained by carefully controlling the doping profile. Photon counting (PC) detection devices in the 1.0-1.6 µm wavelength range are important for LIDAR image, remote sensing, standoff chemical detection, and deep-space communications. Lacking of sufficient single photon detection efficiency (SPDE), one of the most important performance metrics, has been a primary issue for PC devices operating at the near infrared wavelength range. A method to improve single photon avalanche photodiodes (SPADs) performance was proposed by reducing the voltage difference between the punch-through and breakdown voltages of APDs. SPADs based on the proposed structure were fabricated. Results demonstrate the improvement in the leakage current and the I-V characteristics of APDs. Device's dark count probability (DCP) and SPDE were measured using our innovative gated current bias scheme under different operating conditions to obtain a maximum SPDE. We found that the SPDE can be enhanced with the proposed structure and a SPDE of ~ 25% was achieved.
A Network-Based High-Level Data Classification Algorithm Using Betweenness Centrality
Creators: name: Vilca, Esteban
name: Zhao, Liang
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Social and Information Networks (cs.SI)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Data classification is a major machine learning paradigm, which has been widely applied to solve a large number of real-world problems. Traditional data classification techniques consider only physical features (e.g., distance, similarity, or distribution) of the input data. For this reason, those are called \textit{low-level} classification. On the other hand, the human (animal) brain performs both low and high orders of learning and it has a facility in identifying patterns according to the semantic meaning of the input data. Data classification that considers not only physical attributes but also the pattern formation is referred to as \textit{high-level} classification. Several high-level classification techniques have been developed, which make use of complex networks to characterize data patterns and have obtained promising results. In this paper, we propose a pure network-based high-level classification technique that uses the betweenness centrality measure. We test this model in nine different real datasets and compare it with other nine traditional and well-known classification models. The results show us a competent classification performance.
How do the codon assignments of the genetic code influence the evolution of protein coding gene?
Creators: name: Zhu, Wen
Publisher: name: Maryland Shared Open Access Repository
Year: 2007
Subjects: Biology, Bioinformatics (0715)

description: The standard genetic code is non-randomly organized. The Error minimization hypothesis interprets this non-randomness as an adaptation, proposing that natural selection produced a pattern of codon assignments that buffers genomes against the impact of mutations. However, might the case be that its non-random nature affects the rate of adaptive evolution? To investigate this, we develop population genetic simulations to test the rate of adaptive gene evolution under different genetic codes. We identify two independent properties of a genetic code that profoundly influence the speed of adaptive evolution. We offer a new insight into the effects of the error minimizing code: such a code enhances the efficacy of adaptive sequence evolution. Upon studying the effects of the genetic code on adaptive evolution of proteins, we further asked: does it matter how we model adaptive protein evolution? Specifically, what type of fitness function should we use to map the genotype, phenotype and fitness projection: a traditional random fitness function or a non-random fitness function? By comparing different fitness functions in various traditional adaptive models, we concluded: the genetic code's effect on adaptive protein evolution varies according to assumptions about the connection between genotype and phenotype. To understand which assumption more realistically represents adaptive evolution, we merged the field of protein threading algorithms into existing adaptive models. After conducting simulations that made explicit use of sequence-to-structure mapping algorithms, we assert that a model in which mutational effects are constrained by biological meaning is better supported than one in which mutational effects are measured by a random fitness function. The threading model also indicated that genes translated by the standard genetic code outperform those translated by randomized genetic codes. This finding supports our previous simple model.  We also tested the roles of code error value and redundancy. We discovered that code error value alone enhances the adaptive evolution of proteins regardless of mutational bias. However, code redundancy exerts no influence over evolutionary dynamics regardless of mutational bias. This differs from our simple linear model. This inconsistency suggests the detailed relationship between mutational spectra and protein evolution through such neutral networks remains poorly understood.
On the cross-correlation of sub-mm sources and optically-selected galaxies
Creators: name: Blake, Chris
name: Pope, Alexandra
name: Scott, Douglas
name: Mobasher, Bahram
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Bright sub-mm galaxies are expected to arise in massive highly-biased haloes, and hence exhibit strong clustering. We argue that a valuable tool for measuring these clustering properties is the cross-correlation of sub-mm galaxies with faint optically-selected sources. We analyze populations of SCUBA-detected and optical galaxies in the GOODS-N survey area. Using optical/IR photometric-redshift information, we search for correlations induced by two separate effects: (1) cosmic magnification of background sub-mm sources by foreground dark matter haloes traced by optical galaxies at lower redshifts; and (2) galaxy clustering due to sub-mm and optical sources tracing the same population of haloes where their redshift distributions overlap. Regarding cosmic magnification, we find no detectable correlation. Our null result is consistent with a theoretical model for the cosmic magnification, and we show that a dramatic increase in the number of sub-mm sources will be required to measure the effect reliably. Regarding clustering, we find evidence at the 3.5-sigma level for a cross-correlation between sub-mm and optical galaxies analyzed in identical photometric redshift slices. The data hint that the sub-mm sources have an enhanced bias parameter compared to the optically-selected population (with a significance of 2-sigma). The next generation of deep sub-mm surveys can potentially perform an accurate measurement of each of these cross-correlations, adding a new set of diagnostics for understanding the development of massive structure in the Universe.
description: 10 pages, 10 figures, accepted for publication by MNRAS
Interpolation and Gap Filling of Landsat Reflectance Time Series
Creators: name: Moreno-Martinez, Alvaro
name: Maneta, Marco
name: Camps-Valls, Gustau
name: Martino, Luca
name: Robinson, Nathaniel
name: Allred, Brady
name: Running, Steven W
Publisher: name: arXiv
Year: 2020
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Products derived from a single multispectral sensor are hampered by a limited spatial, spectral or temporal resolutions. Image fusion in general and downscaling/blending in particular allow to combine different multiresolution datasets. We present here an optimal interpolation approach to generate smoothed and gap-free time series of Landsat reflectance data. We fuse MODIS (moderate-resolution imaging spectroradiometer) and Landsat data globally using the Google Earth Engine (GEE) platform. The optimal interpolator exploits GEE ability to ingest large amounts of data (Landsat climatologies) and uses simple linear operations that scale easily in the cloud. The approach shows very good results in practice, as tested over five sites with different vegetation types and climatic characteristics in the contiguous US.
Dynamical stability of collisionless stellar systems and barotropic stars: the nonlinear Antonov first law
Creators: name: Chavanis, P. H.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We complete previous investigations on the dynamical stability of barotropic stars and collisionless stellar systems. A barotropic star that minimizes the energy functional at fixed mass is a nonlinearly dynamically stable stationary solution of the Euler-Poisson system. Formally, this minimization problem is similar to a condition of ``canonical stability'' in thermodynamics. A stellar system that maximizes an H-function at fixed mass and energy is a nonlinearly dynamically stable stationary solution of the Vlasov-Poisson system. Formally, this maximization problem is similar to a condition of ``microcanonical stability'' in thermodynamics. Using a thermodynamical analogy, we provide a derivation and an interpretation of the nonlinear Antonov first law in terms of ``ensembles inequivalence'': a spherical stellar system with f=f(epsilon) and f'(epsilon)<0 is nonlinearly dynamically stable with respect to the Vlasov-Poisson system if the corresponding barotropic star with the same equilibrium density distribution is nonlinearly dynamically stable with respect to the Euler-Poisson system. This is similar to the fact that ``canonical stability implies microcanonical stability'' in thermodynamics. The converse is wrong in case of ``ensembles inequivalence'' which is generic for systems with long-range interactions like gravity. We show that criteria of nonlinear dynamical stability can be obtained very simply from purely graphical constructions by using the method of series of equilibria and the turning point argument of Poincare, as in thermodynamics.
The boundary states and correlation functions of the tricritical Ising model from the Coulomb-gas formalism
Creators: name: Balaska, S.
name: Sahabi, T.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We consider the minimal conformal model describing the tricritical Ising model on the disk and on the upper half plane. Using the coulomb-gas formalism we determine its consistents boundary states as well as its 1-point and 2-point correlation functions.
description: 20 pages, no figure. Version 2:A paragraph for the calculation of the 2-point correlators was added. Some typos and garammatical errors were corrected.Version 3: Equations 24 are modified. Version 4 : new introduction and minor corrections
Spin liquid correlations in Nd-langasite anisotropic Kagomé antiferromagnet
Creators: name: Robert, Julien
name: Simonet, Virginie
name: Canals, Benjamin
name: Ballou, Rafik
name: Bordet, Pierre
name: Lejay, Pascal
name: Stunault, Anne
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Dynamical magnetic correlations in the geometrically frustrated Nd$\_3$Ga$\_5$SiO$\_{14}$ compound were probed by inelastic neutron scattering on a single crystal. A scattering signal with a ring shape distribution in reciprocal space and unprecedented dispersive features was discovered. Comparison with calculated static magnetic scattering from models of correlated spins suggests that the observed phase is a spin liquid inherent to an antiferromagnetic kagomé-like lattice of anisotropic Nd moments.
description: 4 pages
Hybrid gap structure in the heavy-fermion superconductor CeIrIn$_5$
Creators: name: Shakeripour, H.
name: Tanatar, M. A.
name: Li, S. Y.
name: Taillefer, Louis
name: Petrovic, C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The thermal conductivity $κ$ of the heavy-fermion superconductor CeIrIn$_5$ was measured as a function of temperature down to $T_c$/8, for current directions perpendicular ($J \parallel a$) and parallel ($J \parallel c$) to the tetragonal c axis. For $J \parallel a$, a sizable residual linear term $κ_0 / T$ is observed, as previously, which confirms the presence of line nodes in the superconducting gap. For $J \parallel c$, on the other hand, $κ/ T \to 0$ as $T \to 0$. The resulting precipitous decline in the anisotropy ratio $κ_c / κ_a$ at low temperature rules out a gap structure with line nodes running along the c-axis, such as the d-wave state favoured for CeCoIn$_5$, and instead points to a hybrid gap of $E_g$ symmetry. It therefore appears that two distinct superconducting states are realized in the Ce$M$In$_5$ family.
description: 4 pages, 3 figures, submitted to Phys. Rev. Lett
Distributed Model Consensus for Models of Locally Biased Measurements in Wireless Sensor Networks
Creators: name: THOMPSON, JACOB W.
Publisher: name: Maryland Shared Open Access Repository
Year: 2012
Subjects: gabp
gaussian belief propagation
gossip averaging
linear regression
model consensus
wireless sensor network

description: Wireless sensor networks (WSNs) consist of interconnected microsensors, each of which collects measurements from its local environment, which are often used in monitoring and control applications.  These applications make inferences about the global and local states of the deployment environment.  However, due to the limited communication and energy resources at the sensors, gathering all the raw data at a central fusion/control point is impractical. Hence, it is essential to have distributed learning and inference in WSNs, such as learning a consensus model from the locally learned models. Consensus is challenging due to the limited resources of the sensors and the inherent bias of the individual sensor models learned from their local sensing environments.  Two leading approaches for this problem are the approach by Zheng et al which uses loopy belief propagation on a certain graphical model based on the WSN topology and the local models, and the approach by Xiao et al which relies on gossip averaging of the parameters of the local models. We focus on multivariate linear regression models, such as Bayesian, Ridge, and LASSO regression models.  We analyze and extend the loopy Gaussian belief propagation (GaBP) approach to model consensus, and compare its performance to the gossip averaging approach.  We experimentally find that GaBP tends to converge much faster than gossip averaging, but to a less accurate estimated consensus model (especially in the presence of multiple cycles in its corresponding graphical model).  We also find that gossip averaging along paths in the WSN, tends to provide much faster convergence to more accurate estimated consensus models as compared to GaBP.
Who has the key? accessing the technology citadel
Creators: name: Kootte, Judith Anne
Publisher: name: University of British Columbia
Year: 2009

description: Perceptions of new technologies originate from well-established community practices and provide arenas for political and social manipulation. In British Columbia (1995-1996) all school districts were required to submit technology plans in order to qualify for targeted funding. These plans publicly embody the social and political organization of gendered technologies and bring into view the social relations and practices in which the texts are embedded. My rationale for constructing this document is to assess the deployment of technology in the education planning of the school districts in British Columbia as evidenced in the narratives of their texts thus making visible the gendered power relations that define the prevailing knowledge and practices of technology. A quantitative analysis of courses related to the areas of science and technology was undertaken wherein class composition was analyzed by sex for both students and instructors. Female students and instructors were not represented in numbers consistent with their representation in the system as a whole. Omission of women in representative numbers in the technology planning process was also found. This brings into direct view the social relations/organization and "biased" practices of the education system. Official government texts preceding the initiative were summarized and District Technology Plans were also analyzed to interpret the social relations and social practices embedded in the texts. Specifically, these texts were examined to determine their understandings and representations in four areas: equity, curriculum, staff development and technology. Generally plans were presented in a manner that suggested factual status with scant engagement with ideas outside of Ministry requirements. Cost effective and efficient delivery of services, programs and resources were depicted as commensurate with the introduction of new technologies and as justification for their introduction. The requisiteness of technology was a common theme in all documents. The detailing of the material tangibles (hardware inventories, cabling, etc.) was virtually universal whereas the detailing of the human enterprise (teacher development, equity issues, and implementation) was relatively deficient in comparison. The connection between technology and the social issues associated with gender equity was not at all developed with the exception of three school districts.
GEORGIA WHEELCHAIR FINAL REPORT 08112014
Creators: name: Curtis, Bruce
Publisher: name: Zenodo
Year: 2021
Subjects: Wheelchair Factory
WHO Wheelchair provision
Community inclusion of persons with disabilities

description: For 5 years, the World Institute on Disability (WID), with the assistance of Whirlwind Wheelchair International (WWI), provided international expert training and technical assistance to the Coalition for Independent Living (CIL) in order to address some of the most basic problems affecting Georgian wheelchair users: 1) Lack of affordable and maneuverable wheelchairs; 2) Lack of wheelchair mobility training; 3) High rates of unemployment of persons with disabilities; and 4) Need to remove architectural and attitudinal barriers to the full integration of persons with mobility impairments in the community. WID’s strategy and approach was to create, with our 4 Georgian NGO partners, a “Georgian Wheelchair Production Network,” by establishing: (1) a sustainable wheelchair production and repair business in Tbilisi, which produces and sells an adult and child model of the manual RoughRider™ indoor-outdoor wheelchair; an electric version of the RoughRider™ wheelchair; pressure relief wheelchair cushions; metal folding ramps; car hand controls and other assistive mobility products for Georgian wheelchair users; (2) postural support seating products and services, according to WHO guidelines, provided by trained and certified (WHO Intermediate and Advanced Services) OTs at clinics held at NDC; (3) the local production of pressure relief cushions in Gori; and (4) small, networked wheelchair sales outreach and repair businesses in Gori and Zugdidi; and (5) supported by Disability Advocacy/Community Accessibility Teams in Tbilisi, Gori and Zugdidi working to improve accessibility and raise awareness of the rights and needs of persons with disabilities in their communities and provide opportunities for mobility skills training for wheelchair-users.
HISTORY OF TOURISM
Creators: name: Bo'tayeva, Sojida
Publisher: name: Zenodo
Year: 2024

description: In this contemporary world, tourism is becoming a large business which plays a key role in the economy of many developed and developing countries. It offers great opportunities especially for developing parts of the globe and emerging economies. Tourism creates a number of job opportunities for the residents of the countries, strengthens the local economy, contributes to local infrastructure development and can help to conserve the natural environment and cultural assets and traditions, and to reduce poverty and inequality. The number of jobs created by tourism in many different areas is significant. These jobs are not only a part of the tourism sector but may also include the agricultural sector, communication sector, health sector, and the educational sector. Many tourists travel to experience the hosting destination’s culture, different traditions ang the gastronomy. This is very profitable to local restaurants, shopping centres, and stores. But do you know when did tourism appear?
Analysis of Generalizability of Deep Neural Networks Based on the Complexity of Decision Boundary
Creators: name: Guan, Shuyue
name: Loew, Murray
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: For supervised learning models, the analysis of generalization ability (generalizability) is vital because the generalizability expresses how well a model will perform on unseen data. Traditional generalization methods, such as the VC dimension, do not apply to deep neural network (DNN) models. Thus, new theories to explain the generalizability of DNNs are required. In this study, we hypothesize that the DNN with a simpler decision boundary has better generalizability by the law of parsimony (Occam's Razor). We create the decision boundary complexity (DBC) score to define and measure the complexity of decision boundary of DNNs. The idea of the DBC score is to generate data points (called adversarial examples) on or near the decision boundary. Our new approach then measures the complexity of the boundary using the entropy of eigenvalues of these data. The method works equally well for high-dimensional data. We use training data and the trained model to compute the DBC score. And, the ground truth for model's generalizability is its test accuracy. Experiments based on the DBC score have verified our hypothesis. The DBC is shown to provide an effective method to measure the complexity of a decision boundary and gives a quantitative measure of the generalizability of DNNs.
description: 7 pages, 11 figures. Accepted by ICMLA 2020
Ditidaht elders’ strategies for the introduction of immersion programs in a First Nation community
Creators: name: Touchie, Bernice
Publisher: name: University of British Columbia
Year: 2009

description: The thesis explores the possibilities for immersion in a First Nation small community whose language survival hinges on the action by the 5% fluent speakers. Curriculum planning is needed at a time when First Nations do not have the resources or experience in teaching their language as a second language and very limited experience with curriculum development and school administration. The author is familiar with the deep emotional desire for effective language programs but the communities cannot find an effective means for truly successful results. The occasional Native teacher searches for methods by learning linguistic strategies or modeling literate classroom lessons. Community leaders face surmounting obstacles while elders pass away with each crucial decade. These obstacles and constraints are not only due to social ills but also to the attempt at developing curriculum with models which do not origninate with the community, the culture, or the language itself. The thesis therefore attempts to find avenues for blending learning strategies of an oral culture and recognizing and validating the culture which embraces the cultural background to the language. The avenues for language revitalization involve ethnographic research which is seen as practical to the community if these are steps toward cultural development. The social issues level is considered as Native language speakers are often adversely effected due to schooling in residential schools. The thesis then concludes the specific needs for the Ditidaht context as concerns community process, as traditional protocol, and as the nature of an effective curriculum (received in generalized concepts from the community interviews). Other First Nation Community strategies are reviewed from many nations throughout Canada and the United States. The Canadian French immersion experience provides a preview into immersion evolution. The research is found necessary for any First Nation community in search of the crucial need for effective second-language curriculum focus.
Use of cumulants to quantify uncertainties in the HBT measurements of the homogeneity regions
Creators: name: Zalewski, K.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Let us denote p(x|K) the space density of the points where identical particles of some kind, e.g. pi+ mesons, with momentum K are produced. When using the HBT method to determine p(x|K) one encounters ambiguities. We show that these ambiguities do not affect the even cumulants of the distribution p(x|K). In particular, the HBT radii of the homogeneity regions, which are given by the second order cumulants, and the distribution of distances between the pairs of production points for particles with momentum K can be reliably measured. The odd cumulants are ambiguous. The are, however, correlated. In particular, when the average position (K) is known as a function of K there is no further ambiguity.
description: LateX, 10 pages, no figures
Letter from Colin C. MacRae to James Goldie, September 11, 1909
Creators: name: MacRae, Colin C.
Publisher: name: The University of British Columbia
Year: 2017

description: Letter to James Goldie from Colin C. MacRae, manager of the Royal Bank of Canada in Vernon, B.C., dated September 11, 1909, regarding request for Goldie's approval on an agreement.
GAN Ensemble for Anomaly Detection
Creators: name: Han, Xu
name: Chen, Xiaohui
name: Liu, Li-Ping
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: When formulated as an unsupervised learning problem, anomaly detection often requires a model to learn the distribution of normal data. Previous works apply Generative Adversarial Networks (GANs) to anomaly detection tasks and show good performances from these models. Motivated by the observation that GAN ensembles often outperform single GANs in generation tasks, we propose to construct GAN ensembles for anomaly detection. In the proposed method, a group of generators and a group of discriminators are trained together, so every generator gets feedback from multiple discriminators, and vice versa. Compared to a single GAN, a GAN ensemble can better model the distribution of normal data and thus better detect anomalies. Our theoretical analysis of GANs and GAN ensembles explains the role of a GAN discriminator in anomaly detection. In the empirical study, we evaluate ensembles constructed from four types of base models, and the results show that these ensembles clearly outperform single models in a series of tasks of anomaly detection.
description: 8 pages, 6 figures. To appear in Proceedings 35th AAAI Conference on Artificial Intelligence (AAAI 21)
Cosmological science enabled by Planck
Creators: name: White, Martin
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Planck will be the first mission to map the entire cosmic microwave background (CMB) sky with mJy sensitivity and resolution better than 10'. The science enabled by such a mission spans many areas of astrophysics and cosmology. In particular it will lead to a revolution in our understanding of primary and secondary CMB anisotropies, the constraints on many key cosmological parameters will be improved by almost an order of magnitude (to sub-percent levels) and the shape and amplitude of the mass power spectrum at high redshift will be tightly constrained.
description: 10 pages, 6 figures, proceedings of the UC Irvine conference on cosmic microwave background temperature and polarization anisotropies
ACDER: Augmented Curiosity-Driven Experience Replay
Creators: name: Li, Boyao
name: Lu, Tao
name: Li, Jiayi
name: Lu, Ning
name: Cai, Yinghao
name: Wang, Shuo
Publisher: name: arXiv
Year: 2020
Subjects: subject: Robotics (cs.RO)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Exploration in environments with sparse feedback remains a challenging research problem in reinforcement learning (RL). When the RL agent explores the environment randomly, it results in low exploration efficiency, especially in robotic manipulation tasks with high dimensional continuous state and action space. In this paper, we propose a novel method, called Augmented Curiosity-Driven Experience Replay (ACDER), which leverages (i) a new goal-oriented curiosity-driven exploration to encourage the agent to pursue novel and task-relevant states more purposefully and (ii) the dynamic initial states selection as an automatic exploratory curriculum to further improve the sample-efficiency. Our approach complements Hindsight Experience Replay (HER) by introducing a new way to pursue valuable states. Experiments conducted on four challenging robotic manipulation tasks with binary rewards, including Reach, Push, Pick&Place and Multi-step Push. The empirical results show that our proposed method significantly outperforms existing methods in the first three basic tasks and also achieves satisfactory performance in multi-step robotic task learning.
Promoting Self-Care Behaviours Among Cancer Caregivers
Creators: name: Wolfe Phillips, Emily
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2021
Subjects: Caregivers
Cancer
Self-care behaviours
Self-determination theory
Mixed-methods
Behaviour change

description: Caregivers play an integral role in the cancer care system in Canada as they provide unpaid care and support for millions of adults living with and beyond cancer. Although caregiving can be a positive experience for some, assuming a caregiving role can be detrimental to caregivers’ own physical and mental health. Research over the past decade has highlighted the negative impacts of caregiving and called for more efforts focused on improving caregivers’ wellbeing. Most interventions targeting caregivers are largely designed to support them in providing care, with little emphasis placed on specifically promoting self-care behaviours. To address this gap, we designed a brief 4-week self-determination theory-based intervention to improve two self-care behaviours (i.e., physical activity and fruit and vegetable consumption) among cancer caregivers. The primary objective of the mixed-methods research presented in this thesis was to assess the feasibility and acceptability of the intervention. Exploratory objectives included understanding participants’ experiences within the intervention. The single-arm intervention was delivered via four weekly video calls to 13 caregivers (mean age=57.6 [15.4 years]) across Canada. The enrollment rate was 62% and the retention, adherence, and fidelity rates ranged from 90 to 99%. The intervention was generally deemed acceptable by participants; however, modifications such as adding psychological support were suggested. Participants’ experiences participating in the intervention were captured within three themes: (1) (Re)prioritizing self-care behaviours; (2) Finding support for self-care behaviours within the caregiving context; and, (3) Becoming a better caregiver through self-care behaviours. Although promising, modifications to the intervention methods are needed to improve enrolment and better meet caregivers’ needs. This study highlights the importance of self-care behaviours for caregivers and provides valuable information on how to foster these behaviours among this population.
Can sterile neutrinos be the dark matter?
Creators: name: Seljak, Uros
name: Makarov, Alexey
name: McDonald, Patrick
name: Trac, Hy
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We use the Ly-alpha forest power spectrum measured by the SDSS and high-resolution spectroscopy observations in combination with cosmic microwave background and galaxy clustering constraints to place limits on a sterile neutrino as a dark matter candidate in the warm dark matter (WDM) scenario. Such a neutrino would be created in the early universe through mixing with an active neutrino and would suppress structure on scales smaller than its free streaming scale. We ran a series of high-resolution hydrodynamic simulations with varying neutrino mass to describe the effect of a sterile neutrino on the Ly-alpha forest power spectrum. We find that the mass limit is m_s >14 keV at 95% c.l. (10keV at 99.9%), which is nearly an order of magnitude tighter constraint than previously published limits and is above the upper limit allowed by X-ray constraints, excluding this candidate as dark matter in this model. The corresponding limit for a neutrino that decoupled early while in thermal equilibrium is 2.5keV (95% c.l.).
description: 4 pages, 2 figures, submitted to PRL
Complementizer variation, multiple verbs
Creators: name: Doko, Jeanne
name: Koutouan, Evelyne
name: Jarvis, Rebecca
name: Russell, Katherine
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2023
Subjects: subject: ebr

description: Eliciting constructions with multiple verbs (e.g. 'I know how to X'), complementizers in embedded imperatives ('I told her to X'), adjectives.
Chemical Evolution in a Protoplanetary Disk within Planet Carved Gaps and Dust Rings
Creators: name: Alarcon, Felipe
name: Teague, Richard
name: Zhang, Ke
name: Bergin, Edwin
name: Barraza-Alfaro, Marcelo
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Recent surveys of protoplanetary disks show that substructure in dust thermal continuum emission maps is common in protoplanetary disks. These substructures, most prominently rings and gaps, shape and change the chemical and physical conditions of the disk, along with the dust size distributions. In this work, we use a thermochemical code to focus on the chemical evolution that is occurring within the gas-depleted gap and the dust-rich ring often observed behind it. The composition of these spatial locations are of great import, as the gas and ice-coated grains will end up being part of the atmospheres of gas giants and/or the seeds of rocky planets. Our models show that the dust temperature at the midplane of the gap increases, enough to produce local sublimation of key volatiles and pushing the molecular layer closer to the midplane, while it decreases in the dust-rich ring, causing a higher volatile deposition onto the dust grain surfaces. Further, the ring itself presents a freeze-out trap for volatiles in local flows powered by forming planets, becoming a site of localized volatile enhancement. Within the gas depleted gap, the line emission depends on several different parameters, such as: the depth of the gap in surface density, the location of the dust substructure, and the abundance of common gas tracers, such as CO. In order to break this uncertainty between abundance and surface density, other methods such as disk kinematics, become necessary to constrain the disk structure and its chemical evolution.
description: 21 pages,16 figures
The Complexity of Monitoring Hyperproperties
Creators: name: Bonakdarpour, Borzoo
name: Finkbeiner, Bernd
Publisher: name: arXiv
Year: 2021
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: We study the runtime verification of hyperproperties, expressed in the temporal logic HyperLTL, as a means to inspect a system with respect to security polices. Runtime monitors for hyperproperties analyze trace logs that are organized by common prefixes in the form of a tree-shaped Kripke structure, or are organized both by common prefixes and by common suffixes in the form of an acyclic Kripke structure. Unlike runtime verification techniques for trace properties, where the monitor tracks the state of the specification but usually does not need to store traces, a monitor for hyperproperties repeatedly model checks the growing Kripke structure. This calls for a rigorous complexity analysis of the model checking problem over tree-shaped and acyclic Kripke structures. We show that for trees, the complexity in the size of the Kripke structure is L-complete independently of the number of quantifier alternations in the HyperLTL formula. For acyclic Kripke structures, the complexity is PSPACE-complete (in the level of the polynomial hierarchy that corresponds to the number of quantifier alternations). The combined complexity in the size of the Kripke structure and the length of the HyperLTL formula is PSPACE-complete for both trees and acyclic Kripke structures, and is as low as NC for the relevant case of trees and alternation-free HyperLTL formulas. Thus, the size and shape of both the Kripke structure and the formula have significant impact on the complexity of the model checking problem.
ModelArchive – a deposition system for persistent archiving of theoretical protein structure models
Creators: name: Behringer, Dario
name: Waterhouse, Andrew
name: Juergen Haas
name: Roth, Steven
name: Tauriello, Gerardo
name: Schwede, Torsten
Publisher: name: F1000 Research Limited
Year: 2019

description: Since 2006, the Protein Data Bank (PDB) only archives protein structures that have been determined experimentally. Recently, PDB-Dev has been established as a prototype archiving system for structural models obtained through integrative/hybrid (I/H) methods. However, purely theoretical models of macromolecular structures cannot be deposited in either system. At the same time, the application of computational macromolecular models in life science research has rapidly increased in recent years thanks to improved accuracy of the prediction algorithms and more reliable methods for model quality estimation. Archiving of those models is crucial for interpretation and reproducibility of results published in the scientific literature. To address this need, we have created ModelArchive following a community workshop recommendation with the aim of persistent archiving of these models.

ModelArchive (https://modelarchive.org/) provides stable accession codes (DOI) for depositions associated with a publication. Besides the model coordinates, details about modelling methods, parameters and constraints are archived. Reviewers can access these details to check a model prior to publication. All models are searchable and publicly accessible under an open license following FAIR data principles. To date, ModelArchive contains 1'591 theoretical model depositions.
The Emerging Threats of Deepfake Attacks and Countermeasures
Creators: name: Buo, Shadrack Awah
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cryptography and Security (cs.CR)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Deepfake technology (DT) has taken a new level of sophistication. Cybercriminals now can manipulate sounds, images, and videos to defraud and misinform individuals and businesses. This represents a growing threat to international institutions and individuals which needs to be addressed. This paper provides an overview of deepfakes, their benefits to society, and how DT works. Highlights the threats that are presented by deepfakes to businesses, politics, and judicial systems worldwide. Additionally, the paper will explore potential solutions to deepfakes and conclude with future research direction.
description: 5
Star Formation in a Cosmological Simulation of Reionization
Creators: name: Harford, A. Gayler
name: Gnedin, Nickolay Y.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the luminosity functions of high-redshift galaxies in detailed hydrodynamic simulations of cosmic reionization, which are designed to reproduce the evolution of the Lyman-alpha forest between z=5 and z=6. We find that the luminosity functions and total stellar mass densities are in agreement with observations when plausible assumptions about reddenning at z=6 are made. Our simulations support the conclusion that stars alone reionized the universe.
description: Accepted for publication in ApJ
Optimal conditions for multiplexing information into ring-core optical fibers
Creators: name: Rojas-Rojas, Santiago
name: Cañas, Gustavo
name: Saavedra, Gabriel
name: Sepulveda, Esteban
name: Walborn, Stephen
name: Lima, Gustavo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Signal Processing (eess.SP)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In optical communications, space-division multiplexing is a promising strategy to augment the fiber network capacity. It relies on modern fiber designs that support the propagation of multiple spatial modes. One of these fibers, the ring-core fiber (RCF), is able to propagate modes that carry orbital angular momentum (OAM), and has been shown to enhance not only classical, but also quantum communication systems. Typically, the RCF spatial modes are used as orthogonal transmission channels for data streams that are coupled into the fiber using different Laguerre-Gaussian (LG) beams. Here, we study the optimal conditions to multiplex information into ring-core fibers in this scheme. We determine which are the most relevant LG beams to be considered, and how their coupling efficiency can be maximized by properly adjusting the beam width with respect to the fiber parameters. Our results show that the coupling efficiency depends upon the OAM value, and that this can limit the achievable transmission rates. In this regard, we show that LG beams are not the optimal choice to couple information into RCF. Rather, another class of OAM-carrying beam, the perfect vortex beam, allows for nearly perfect coupling efficiencies for all spatial modes supported by these fibers.