cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Weak localization of electromagnetic waves and radar polarimetry of Saturn's rings
Creators: name: Mishchenko, Michael I.
name: Dlugach, Janna M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We use a state-of-the-art physics-based model of electromagnetic scattering to analyze average circular polarization ratios measured for the A and B rings of Saturn at a wavelength of 12.6 cm. This model is directly based on the Maxwell equations and accounts for the effects of polarization, multiple scattering, weak localization of electromagnetic waves, and ring particle nonsphericity. Our analysis is based on the assumption that the observed polarization ratios are accurate, mutually consistent, and show a quasi-linear dependence on the opening angle. Also, we assume that the ring system is not strongly stratified in the vertical direction. Our numerical simulations rule out the model of spherical ring particles, favor the model of ring bodies in the form of nearly spherical particles with small-scale surface roughness, and rule out nonspherical particles with aspect ratios significantly exceeding 1.2. They also favor particles with effective radii in the range 4-10 cm and definitely rule out effective radii significantly smaller than 4 cm. Furthermore, they seem to rule out effective radii significantly greater than 10 cm. The retrieved ring optical thickness values are in the range 2-3 or even larger. If the rings do have a wake-like horizontal structure, as has been recently suggested, then these optical thickness values should be attributed to an average wake rather than to the optical thickness averaged over the entire horizontal extent of the rings.
Extended Kohler$^,$s Rule of Magnetoresistance
Creators: name: Xu, Jing
name: Han, Fei
name: Wang, Ting-Ting
name: Thoutam, Laxman R.
name: Pate, Samuel E.
name: Li, Mingda
name: Zhang, Xufeng
name: Wang, Yong-Lei
name: Fotovat, Roxanna
name: Welp, Ulrich
name: Zhou, Xiuquan
name: Kwok, Wai-Kwong
name: Chung, Duck Young
name: Kanatzidis, Mercouri G.
name: Xiao, Zhi-Li
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: A notable phenomenon in topological semimetals is the violation of Kohler$^,$s rule, which dictates that the magnetoresistance $MR$ obeys a scaling behavior of $MR = f(H/ρ_0$), where $MR = [ρ_H-ρ_0]/ρ_0$ and $H$ is the magnetic field, with $ρ_H$ and $ρ_0$ being the resistivity at $H$ and zero field, respectively. Here we report a violation originating from thermally-induced change in the carrier density. We find that the magnetoresistance of the Weyl semimetal, TaP, follows an extended Kohler$^,$s rule $MR = f[H/(n_Tρ_0)]$, with $n_T$ describing the temperature dependence of the carrier density. We show that $n_T$ is associated with the Fermi level and the dispersion relation of the semimetal, providing a new way to reveal information on the electronic bandstructure. We offer a fundamental understanding of the violation and validity of Kohler$^,$s rule in terms of different temperature-responses of $n_T$. We apply our extended Kohler$^,$s rule to BaFe$_2$(As$_{1-x}$P$_x$)$_2$ to settle a long-standing debate on the scaling behavior of the normal-state magnetoresistance of a superconductor, namely, $MR$ ~ $tan^2θ_H$, where $θ_H$ is the Hall angle. We further validate the extended Kohler$^,$s rule and demonstrate its generality in a semiconductor, InSb, where the temperature-dependent carrier density can be reliably determined both theoretically and experimentally.
LBCF: A Large-Scale Budget-Constrained Causal Forest Algorithm
Creators: name: Ai, Meng
name: Li, Biao
name: Gong, Heyang
name: Yu, Qingwei
name: Xue, Shengjie
name: Zhang, Yuan
name: Zhang, Yunzhou
name: Jiang, Peng
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Offering incentives (e.g., coupons at Amazon, discounts at Uber and video bonuses at Tiktok) to user is a common strategy used by online platforms to increase user engagement and platform revenue. Despite its proven effectiveness, these marketing incentives incur an inevitable cost and might result in a low ROI (Return on Investment) if not used properly. On the other hand, different users respond differently to these incentives, for instance, some users never buy certain products without coupons, while others do anyway. Thus, how to select the right amount of incentives (i.e. treatment) to each user under budget constraints is an important research problem with great practical implications. In this paper, we call such problem as a budget-constrained treatment selection (BTS) problem. The challenge is how to efficiently solve BTS problem on a Large-Scale dataset and achieve improved results over the existing techniques. We propose a novel tree-based treatment selection technique under budget constraints, called Large-Scale Budget-Constrained Causal Forest (LBCF) algorithm, which is also an efficient treatment selection algorithm suitable for modern distributed computing systems. A novel offline evaluation method is also proposed to overcome an intrinsic challenge in assessing solutions' performance for BTS problem in randomized control trials (RCT) data. We deploy our approach in a real-world scenario on a large-scale video platform, where the platform gives away bonuses in order to increase users' campaign engagement duration. The simulation analysis, offline and online experiments all show that our method outperforms various tree-based state-of-the-art baselines. The proposed approach is currently serving over hundreds of millions of users on the platform and achieves one of the most tremendous improvements over these months.
description: Published in Web Conference 2022 (WWW'2022)
Neural networks in 3D medical scan visualization
Creators: name: Zukić, Dženan
name: Elsner, Andreas
name: Avdagić, Zikrija
name: Domik, Gitta
Publisher: name: arXiv
Year: 2008
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Graphics (cs.GR)
subject: FOS: Computer and information sciences
subject: I.3; I.2.6

description: For medical volume visualization, one of the most important tasks is to reveal clinically relevant details from the 3D scan (CT, MRI ...), e.g. the coronary arteries, without obscuring them with less significant parts. These volume datasets contain different materials which are difficult to extract and visualize with 1D transfer functions based solely on the attenuation coefficient. Multi-dimensional transfer functions allow a much more precise classification of data which makes it easier to separate different surfaces from each other. Unfortunately, setting up multi-dimensional transfer functions can become a fairly complex task, generally accomplished by trial and error. This paper explains neural networks, and then presents an efficient way to speed up visualization process by semi-automatic transfer function generation. We describe how to use neural networks to detect distinctive features shown in the 2D histogram of the volume data and how to use this information for data classification.
description: 8 pages, 6 figures published on conference 3IA'2008 in Athens, Greece (http://3ia.teiath.gr)
Solving the Eikonal equation for compressional and shear waves in anisotropic media using peridynamic differential operator
Creators: name: Bekar, Ali Can
name: Madenci, Erdogan
name: Haghighat, Ehsan
name: Waheed, Umair bin
name: Alkhalifah, Tariq
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The traveltime of compressional (P) and shear (S) waves have proven essential in many applications of earthquake and exploration seismology. An accurate and efficient traveltime computation for P and S waves is crucial for the success of these applications. However, solutions to the Eikonal equation with a complex phase velocity field in anisotropic media is challenging. The Eikonal equation is a first-order, hyperbolic, nonlinear partial differential equation (PDE) that represents the high-frequency asymptotic approximation of the wave equation. The fast marching and sweeping methods are commonly used due to their efficiency in numercally solving Eikonal equation. However, these methods suffer from numerical inaccuracy in anisotropic media with sharp heterogeneity, irregular surface topography and complex phase velocity fields. This study presents a new method to solving the Eikonal equation by employing the peridynamic differential operator (PDDO). The PDDO provides the nonlocal form of the Eikonal equation by introducing an internal length parameter (horizon) and a weight function with directional nonlocality. The operator is immune to discontinuities in the form sharp changes in field or model variables and invokes the direction of traveltime in a consistent manner. The weight function controls the degree of association among points within the horizon. Solutions are constructed in a consistent manner without upwind assumptions through simple discretization. The capability of this approach is demonstrated by considering different types of Eikonal equations on complex velocity models in anisotropic media. The examples demonstrate its unconditional numerical stability and results compare well with the reference solutions.
description: 30 pages, 26 figures
The Work of Art in the Age of the Australian Misanthropocene
Creators: name: Titmarsh, Mark
name: Transdisciplinary Imaging Conference 2020, Dark Eden
Publisher: name: figshare
Year: 2021
Subjects: subject: 190104 Visual Cultures
subject: FOS: Arts (arts, history of arts, performing arts, music)

description: Through metaphors provided by the Covid Safe app we can say that our relations with technology are inseparable from our coming into being, they design and seek to predetermine our socio-communicative (well) being. Yet it is an uncanny kind of (well) being since it is dissociated from any sense of location. Just as the moment of blue tooth handshake is not tied to a specific place, only the fact that there has been a rendezvous of viral proximity. In this way the truth of being has become unbound from place, since place has become an environment of code-space, a world of techno-mediation. In Australia this means that the process of de-localisation that began with the arrival of Cook has culminated in a variety of colonisations that operates at the level of both land and subjectivity.In this paper I will argue that the counter-project of decolonisation is a movement of liberation to twistfree from the failed Western project of Modernity and its latest emanation in contemporary digital technologies. The former is captured in the single word the Anthropocene, the geographic era when human activity negatively determines the health of the global system. The latter is the latest version of hyper capitalism, masking capitalism’s colonial past with the gloss of techno-mediated connectivity. Using the writings of David Chandler, Bruno Latour and Martin Heidegger I will show that Australia has become the epicentre for the MisAnthropocene, a colonial nonplace where the failure of the enlightenment project, of modernity itself, is being played out as the failure of colonialism, both the crude legalistic version of terra nullius and the networked variety of data colonisation carried out in the back end of social media.This will involve a re-examination of the contemporary image and historical modes of visualisation, reaching from 18th century looking-as-possessing carried out by Lieutenant (Captain) Cook, 20th Century postmodern appropriation practices as a kind of hyperactive glancing in the work of Tillers and Johnston, and finally the long stare of digital surveillance in social media of the 21st Century.
title: Front Matter, Table of Contents, Preface, Awards, Conference Organization, External Reviewers
Creators: name: O'Donnell, Ryan
Publisher: name: Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Year: 2017
Subjects: subject: Front Matter
subject: Table of Contents
subject: Preface
subject: Awards
subject: Conference Organization
subject: External Reviewers
subject: List of Authors

description: Front Matter, Table of Contents, Preface, Awards, Conference Organization, External Reviewers, List of Authors
description: LIPIcs, Vol. 79, 32nd Computational Complexity Conference (CCC 2017), pages 0:i-0:xiv
TSI: an Ad Text Strength Indicator using Text-to-CTR and Semantic-Ad-Similarity
Creators: name: Mishra, Shaunak
name: Hu, Changwei
name: Verma, Manisha
name: Yen, Kevin
name: Hu, Yifan
name: Sviridenko, Maxim
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computation and Language (cs.CL)
subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Coming up with effective ad text is a time consuming process, and particularly challenging for small businesses with limited advertising experience. When an inexperienced advertiser onboards with a poorly written ad text, the ad platform has the opportunity to detect low performing ad text, and provide improvement suggestions. To realize this opportunity, we propose an ad text strength indicator (TSI) which: (i) predicts the click-through-rate (CTR) for an input ad text, (ii) fetches similar existing ads to create a neighborhood around the input ad, (iii) and compares the predicted CTRs in the neighborhood to declare whether the input ad is strong or weak. In addition, as suggestions for ad text improvement, TSI shows anonymized versions of superior ads (higher predicted CTR) in the neighborhood. For (i), we propose a BERT based text-to-CTR model trained on impressions and clicks associated with an ad text. For (ii), we propose a sentence-BERT based semantic-ad-similarity model trained using weak labels from ad campaign setup data. Offline experiments demonstrate that our BERT based text-to-CTR model achieves a significant lift in CTR prediction AUC for cold start (new) advertisers compared to bag-of-words based baselines. In addition, our semantic-textual-similarity model for similar ads retrieval achieves a precision@1 of 0.93 (for retrieving ads from the same product category); this is significantly higher compared to unsupervised TF-IDF, word2vec, and sentence-BERT baselines. Finally, we share promising online results from advertisers in the Yahoo (Verizon Media) ad platform where a variant of TSI was implemented with sub-second end-to-end latency.
description: Accepted for publication at CIKM 2021
A Note on Dominant Contractions of Jordan Algebras
Creators: name: Mukhamedov, Farrukh
name: Temir, Seyit
name: Akin, Hasan
Publisher: name: arXiv
Year: 2008
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 47A35, 17C65, 46L70, 46L52, 28D05

description: In the paper we consider two positive contractions $T,S:L^{1}(A,τ)\longrightarrow L^{1}(A,τ)$ such that $T\leq S$, here $(A,\t)$ is a semi-finite $JBW$-algebra. If there is an $n_{0}\in\mathbb{N}$ such that $\|S^{n_{0}}-T^{n_{0}}\|<1$. Then we prove that $\|S^{n}-T^{n}\|<1$ holds for every $n\geq n_{0}.$
description: 9 pages. Turkish Journal of Mathematics (to appear)
Hot Quark Matter with Neutrino Confinement in the Framework of the Local Nambu--Jona-Lasinio SU(3) Model
Creators: name: Hajyan, G. S.
name: Alaverdyan, G. B.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The thermodynamic characteristics of hot $β$-equilibrium electrically neutral three-flavor quark matter at neutrino confinement are investigated. For the thermodynamic description of such a quark-lepton system, the local SU (3) Nambu--Jona-Lasinio (NJL) model is used, in which also takes into account the 't Hooft interaction, leading to the quark flavor mixing effect. The energy density $\varepsilon$ and pressure $P$ of quark matter are numerically determined for different values of the baryon number density in the range $n_B\in[0.02÷1.8]$ fm$^{-3}$ and temperatures in the range $T\in[0÷100]$ MeV. The results obtained are compared with the results of cold quark matter calculated within the framework of the same model, but under the assumption that all neutrinos have already left the system. The dependence of the contribution of individual quark flavors to the baryon charge of the system at different temperatures is discussed. Both isothermal and adiabatic speeds of sound in hot quark matter are determined depending on the baryon number density.
description: 15 pages, 8 figures
Comment on "Casimir Force Acting on Magnetostatic Bodies Embedded in Media"
Creators: name: Brevik, Iver
name: Ellingsen, Simen A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In a recent paper [C. Raabe and D.-G. Welsch, Phys. Rev. A 71, 013814 (2005)] an electromagnetic energy-momentum tensor is suggested as an alternative to the Abraham-Minkowski tensor and is applied to calculations of Casimir forces in planar geometries. We argue that the universality of the suggested tensor is doubtful; application of the Raabe-Welsch theory to a simple example in classical electrodynamics shows that their proposed tensor is unable to describe the situation in a simple way. We also show that modified Casimir forces acting on the cavity medium as prescribed by these authors suffer from problems of definiteness and peculiar properties which call for experimental support before this theory can be regarded as acceptable.
description: 11 pages, 2 figures
Radio constraints on dark matter annihilation in the galactic halo and its substructures
Creators: name: Borriello, Enrico
name: Cuoco, Alessandro
name: Miele, Gennaro
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Annihilation of Dark Matter usually produces together with gamma rays comparable amounts of electrons and positrons. The e+e- gyrating in the galactic magnetic field then produce secondary synchrotron radiation which thus provides an indirect mean to constrain the DM signal itself. To this purpose, we calculate the radio emission from the galactic halo as well as from its expected substructures and we then compare it with the measured diffuse radio background. We employ a multi-frequency approach using data in the relevant frequency range 100 MHz-100 GHz, as well as the WMAP Haze data at 23 GHz. The derived constraints are of the order =10^{-24} cm3 s^{-1} for a DM mass m_chi=100 GeV sensibly depending however on the astrophysical uncertainties, in particular on the assumption on the galactic magnetic field model. The signal from single bright clumps is instead largely attenuated by diffusion effects and offers only poor detection perspectives.
description: 12 pages, 7 figures; v2: some references added, some discussions enlarged; matches journal version
Van der Waals Anomaly
Creators: name: Efrat, Itai Y.
name: Leonhardt, Ulf
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: In inhomogeneous dielectric media the divergence of the electromagnetic stress is related to the gradients of \varepsilon and μ, which is a consequence of Maxwell's equations. Investigating spherically symmetric media we show that this seemingly universal relationship is violated for electromagnetic vacuum forces such as the generalized van der Waals and Casimir forces. The stress needs to acquire an additional anomalous pressure. The anomaly is a result of renormalization, the need to subtract infinities in the stress for getting a finite, physical force. The anomalous pressure appears in the stress in media like dark energy appears in the energy-momentum tensor in general relativity. We propose and analyse an experiment to probe the van der Waals anomaly with ultracold atoms. The experiment may not only test an unusual phenomenon of quantum forces, but also an analogue of dark energy, shedding light where nothing is known empirically.
Are the red halos of galaxies made of low-mass stars? Constraints from subdwarf star counts in the Milky Way halo
Creators: name: Zackrisson, E.
name: Flynn, C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Surface photometry detections of red and exceedingly faint halos around galaxies have resurrected the old question of whether some non-negligible fraction of the missing baryons of the Universe could be hiding in the form of faint, hydrogen-burning stars. The optical/near-infrared colours of these red halos have proved very difficult to reconcile with any normal type of stellar population, but can in principle be explained by advocating a bottom-heavy stellar initial mass function. This implies a high stellar mass-to-light ratio and hence a substantial baryonic mass locked up in such halos. Here, we explore the constraints imposed by current observations of ordinary stellar halo subdwarfs on a putative red halo of low-mass stars around the Milky Way. Assuming structural parameters similar to those of the red halo recently detected in stacked images of external disk galaxies, we find that a smooth halo component with a bottom-heavy initial mass function is completely ruled out by current star count data for the Milky Way. All viable smooth red halo models with a density slope even remotely similar to that of the stacked halo moreover contain far too little mass to have any bearing on the missing-baryon problem. However, we note that these constraints can be sidestepped if the red halo stars are locked up in star clusters, and discuss potential observations of other nearby galaxies that may be able to put such scenarios to the test.
description: 11 pages, 5 figures, ApJ, in press
Knowledge-Based System Techniques with Applications to Power Systems
Creators: Intelligent Systems Applications Working Group
Publisher: name: IEEE
Year: 1993

Our Goal is to provide information on the new technologies and their applications to practical engineers, consultants, and researchers in a one-day course. This project was sponsored by the Working Group on Artificial Intelligence (AI) Applications, Power System Engineering Committee of the IEEE Power Engineering Society.
Our Goal is to provide information on the new technologies and their applications to practical engineers, consultants, and researchers in a one-day course. This project was sponsored by the Working Group on Artificial Intelligence (AI) Applications, Power System Engineering Committee of the IEEE Power Engineering Society.
Suggested Techniques for Voltage Stability Analysis
Creators: Working Group on Voltage Stability
Publisher: name: IEEE
Year: 1993

The IEEE Working Group on Voltage Stability is pleased to present its second special publication on the subject. Judging by the wide distribution of and referral to our first publication [90TH0358-2-PWR] has been one of the most comprehensive references on the subject that helped guide researchers and power system analysts in dealing with the phenomenon. At the time of its publication, there was noticeable disagreement on the definition and the dynamics of the phenomenon and how it relates to other forms of system instability. Although it did not answer all the questions, it helped focus discussions and activities around the crucial issues. Since then, a better understanding has been developed and specialized tools and analytical methods have evolved to the point where the Working Group feels timely to recommend a set of tools for voltage stability analysis ranging from the simplified conceptual analysis to the detailed long-term dynamic simulation.
The IEEE Working Group on Voltage Stability is pleased to present its second special publication on the subject. Judging by the wide distribution of and referral to our first publication [90TH0358-2-PWR] has been one of the most comprehensive references on the subject that helped guide researchers and power system analysts in dealing with the phenomenon. At the time of its publication, there was noticeable disagreement on the definition and the dynamics of the phenomenon and how it relates to other forms of system instability. Although it did not answer all the questions, it helped focus discussions and activities around the crucial issues. Since then, a better understanding has been developed and specialized tools and analytical methods have evolved to the point where the Working Group feels timely to recommend a set of tools for voltage stability analysis ranging from the simplified conceptual analysis to the detailed long-term dynamic simulation.
Influence of sedimentary layering on tsunami generation
Creators: name: Dutykh, Denys
name: Dias, Frédéric
Publisher: name: arXiv
Year: 2008
Subjects: subject: Geophysics (physics.geo-ph)
subject: Numerical Analysis (math.NA)
subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Classical Physics (physics.class-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The present article is devoted to the influence of sediment layers on the process of tsunami generation. The main scope here is to demonstrate and especially quantify the effect of sedimentation on vertical displacements of the seabed due to an underwater earthquake. The fault is modelled as a Volterra-type dislocation in an elastic half-space. The elastodynamics equations are integrated with a finite element method. A comparison between two cases is performed. The first one corresponds to the classical situation of an elastic homogeneous and isotropic half-space, which is traditionally used for the generation of tsunamis. The second test case takes into account the presence of a sediment layer separating the oceanic column from the hard rock. Some important differences are revealed. We conjecture that deformations in the generation region may be amplified by sedimentary deposits, at least for some parameter values. The mechanism of amplification is studied through careful numerical simulations.
description: 17 pages, 12 figures. Revised version for Computer Methods in Applied Mechanics and Engineering. Other author's papers can be downloaded from http://www.lama.univ-savoie.fr/~dutykh/
Microwave Communication Channels For Protective Relaying Applications
Creators: Microwave Communications for Relaying Applications Working Group
Publisher: name: IEEE
Year: 1985

The purpose of this guide is to familiarize system protection engineers with the use of microwave radio as a telecommunications channel for protective relaying. Many utilities have or are building a microwave system for transmission of voice, data, telemetry and SCADA. In view of the increasing importance of these functions, modern microwave systems are designed to be extremely reliable, and are thus well-suited for many protective relaying applications.
The purpose of this guide is to familiarize system protection engineers with the use of microwave radio as a telecommunications channel for protective relaying. Many utilities have or are building a microwave system for transmission of voice, data, telemetry and SCADA. In view of the increasing importance of these functions, modern microwave systems are designed to be extremely reliable, and are thus well-suited for many protective relaying applications.
title:  Introduction. Aesthetics and the Everyday. Une Liaison Dangereuse
Creators: name: Kvokačka, Adrián
name: Giombini, Lisa
Publisher: name: Roma TrE-Press
Year: 2021

description: What is the philosophy of everydayness and why is it important (if ever)? And what is the role of aesthetics in our dealings with everyday life? This introduction examines some crucial issues that emerge when considering the notion of everydayness from a philosophical perspective. It offers a trajectory of the main approaches to the notion of everyday life that are relevant to understanding its contemporary developments. While interest in the everyday aspects of reality has been a neglected feature in the history of Western thought, everydayness has re-emerged recently as a central theme in aesthetics. The introduction also surveys the papers included in the collection and provides insight into their organization.
description: Everydayness. Contemporary Aesthetic Approaches
Adaptive Coordination of Damping Controllers for Enhanced Power System Stability
Creators: Horacio Silva-Saravia
Héctor Pulgar-Painemal
David A. Schoenwald
and Wenyun Ju
Publisher: name: IEEE
Year: 2020

This paper introduces the concept of adaptive coordination of damping controllers for enhancing power system stability.
This paper introduces the concept of adaptive coordination of damping controllers for enhancing power system stability. The coordination uses phasor measurement units (PMUs) to adapt to different disturbances by selecting the switching status (on/off) of damping controllers that minimizes an energy-based dynamic performance measure. This dynamic performance measure, referred to as total action (TA), uses a physical interpretation of excited modes rather than fixed targeted modes as in the traditional damping control design. The coordination is formulated as a binary integer programming problem, which is solved by using the total action sensitivity (TAS). The concept of oscillation energy and the implementation of the adaptive coordination scheme is tested in the western North America power system (wNAPS). The results show that the proposed adaptive control scheme can improve oscillation damping for different short-circuit locations even in the presence of large communication delays.
The Effects of Human Aspects on the Requirements Engineering Process: A Systematic Literature Review
Creators: name: Hidellaarachchi, Dulaji
name: Grundy, John
name: Hoda, Rashina
name: Madampe, Kashumi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Requirements Engineering (RE) requires the collaboration of various roles in SE, such as requirements engineers, stakeholders and other developers, and it is thus a highly human dependent process in software engineering (SE). Identifying how human aspects such as personality, motivation, emotions, communication, gender, culture and geographic distribution might impact RE would assist us in better supporting successful RE. The main objective of this paper is to systematically review primary studies that have investigated the effects of various human aspects on RE. A systematic literature review (SLR) was conducted and identified 474 initial primary research studies. These were eventually filtered down to 74 relevant, high-quality primary studies. Among the studies, the effects of communication have been considered in many RE studies. Other human aspects such as personality, motivation and gender have mainly been investigated to date related to SE studies including RE as one phase. Findings show that studying more than one human aspect together is beneficial, as this reveals relationships between various human aspects and how they together impact the RE process. However, the majority of these studied combinations of human aspects are unique. From 56.8% of studies that identified the effects of human aspects on RE, 40.5% identified the positive impact, 30.9% negative, 26.2% identified both impacts whereas 2.3% mentioned that there was no impact. This implies that a variety of human aspects positively or negatively affects the RE process and a well-defined theoretical analysis on the effects of different human aspects on RE remains to be defined and practically evaluated. Findings of this SLR help researchers who are investigating the impact of various human aspects on RE by identifying well-studied research areas, and highlight new areas that should be focused on in future research.
description: Published in IEEE Transactions on Software Engineering (Early Access), 25 pages, 16 tables, 9 figures
Meeting Temporary Facility Energy Demand With Climate-Optimized Off-Grid Energy Systems
Creators: Jay Pearson
Torrey Wagner
Justin Delorit
and Steven Schuldt
Publisher: name: IEEE
Year: 2020

To assist planners, this paper proposes an innovative, climate-optimized, hybrid energy system selection model capable of selecting the facility insulation type, solar array size, and battery backup system to minimize the annual operating cost.
Remote and contingency operations, including military and disaster-relief activities, often require the use of temporary facilities powered by inefficient diesel generators that are expensive to operate and maintain. Site planners can reduce operating costs by increasing shelter insulation and augmenting generators with photovoltaic-battery hybrid energy systems, but they must select the optimal design configuration based on the region's climate to meet the power demand at the lowest cost. To assist planners, this paper proposes an innovative, climate-optimized, hybrid energy system selection model capable of selecting the facility insulation type, solar array size, and battery backup system to minimize the annual operating cost. To demonstrate the model's capability in various climates, model performance was evaluated for applications in southwest Asia and the Caribbean. For a facility in Southwest Asia, the model reduced fuel consumption by 93% and saved $271 thousand compared to operating a diesel generator. The simulated facility in the Caribbean resulted in more significant savings, decreasing fuel consumption by 92% and saving $291 thousand. This capability is expected to support planners of remote sites in their ongoing effort to minimize fuel supply requirements and annual operating costs of temporary facilities.
FAPI Controller for Frequency Support in Low-Inertia Power Systems
Creators: Elyas Rakhshani
Arcadio Perilla
José L. Rueda Torres
Francisco M. Gonzalez-Longatt
Thiago Batista Soeiro
and Mart A. M. M. van der Meijden
Publisher: name: IEEE
Year: 2020

This paper presents different forms of Fast Active Power Injection (FAPI) control schemes for the analysis and development of different mitigation measures to address the frequency stability problem due to the growth of the penetration level of the Power Electronic Interfaced Generation (PEIG) in sustainable interconnected energy systems.
This paper presents different forms of Fast Active Power Injection (FAPI) control schemes for the analysis and development of different mitigation measures to address the frequency stability problem due to the growth of the penetration level of the Power Electronic Interfaced Generation (PEIG) in sustainable interconnected energy systems. Among the studied FAPI control schemes, two different approaches in the form of a derivative-based control and a virtual synchronous power (VSP) based control for wind turbine applications are also proposed. All schemes are attached to the PEIG represented by a generic model of wind turbines type 4. The derivative-based FAPI control is applied as an extension of the droop based control scheme, which is dependent on the measurement of the network frequency. By contrast, the proposed VSP-based FAPI is fed by the measurement of the active power deviation. Additionally, unlike existing approaches for virtual synchronous machines, which are characterized by high-order transfer functions, the proposed VSP-based FAPI is defined by a second-order transfer function, which can contribute to fast mitigation of the system primary frequency deviations during containment period. The Great Britain (GB) test system, for the Gone-Green planning scenario for the year 2030 (GG2030), is used to evaluate the effects of the proposed FAPI controllers on the dynamics of the system frequency within the frequency containment period. Thanks to proposed FAPI controllers, it is possible to reach up to 70% for the share of wind power generation without violating the threshold limits for frequency stability. For verification purposes, a full-scale wind turbine facilitated with each FAPI controller is tested in EMT real-time simulation environment.
Tilted Platforms: Rental Housing Technology and the Rise of Urban Big Data Oligopolies
Creators: name: Boeing, Geoff
name: Besbris, Max
name: Wachsmuth, David
name: Wegmann, Jake
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Economics (econ.GN)
subject: Computers and Society (cs.CY)
subject: FOS: Economics and business
subject: FOS: Computer and information sciences

description: This article interprets emerging scholarship on rental housing platforms -- particularly the most well-known and used short- and long-term rental housing platforms - and considers how the technological processes connecting both short-term and long-term rentals to the platform economy are transforming cities. It discusses potential policy approaches to more equitably distribute benefits and mitigate harms. We argue that information technology is not value-neutral. While rental housing platforms may empower data analysts and certain market participants, the same cannot be said for all users or society at large. First, user-generated online data frequently reproduce the systematic biases found in traditional sources of housing information. Evidence is growing that the information broadcasting potential of rental housing platforms may increase rather than mitigate sociospatial inequality. Second, technology platforms curate and shape information according to their creators' own financial and political interests. The question of which data -- and people -- are hidden or marginalized on these platforms is just as important as the question of which data are available. Finally, important differences in benefits and drawbacks exist between short-term and long-term rental housing platforms, but are underexplored in the literature: this article unpacks these differences and proposes policy recommendations.
Optimal Energy Dispatch of Distributed PVs for the Next Generation of Distribution Management Systems
Creators: Fei Ding
Yingchen Zhang
Jeffery Simpson
Andrey Bernstein
and Subramanian Vadari
Publisher: name: IEEE
Year: 2020

This paper proposes an optimal energy dispatch strategy controlling distributed photovoltaic systems for regulating distribution voltages and achieving conservation voltage reduction.
Advanced Distribution Management Systems (ADMS) are being widely adopted by electric utilities for managing and optimizing the operations of their distribution systems. Distributed photovoltaic (DPV) systems with smart inverters can be controlled to adjust active power and reactive power outputs, and they are envisioned to become a part of (centrally or distributed) controllable assets managed by the ADMS for optimizing grid operations. This paper proposes an optimal energy dispatch strategy controlling DPV systems for regulating distribution voltages and achieving conservation voltage reduction. A convex optimization model is proposed with the use of linearized power flow, and the gradient projection algorithm is used to solve the optimal active power and reactive power outputs of smart inverters. The proposed optimal energy dispatch is implemented using an open-source ADMS platform, and simulation results have demonstrated the effectiveness of the proposed approach on improving distribution grid operations.
Energy Consumption Model for Indoor Cannabis Cultivation Facility
Creators: Nafeesa Mehboob
Hany E. Z. Farag
and Abdullah M. Sawas
Publisher: name: IEEE
Year: 2020

This paper proposes a deterministic energy consumption model for indoor cannabis cultivation operations for the two major loads in these facilities, i.e., lighting and HVAC, over a 24-hour period based on equipment specifications and operational requirements of the facility.
The recent legalization of cannabis is facilitating very rapid growth in the cannabis cultivation industry, with the energy intensive indoor cultivation facilities becoming more prevalent. This presents a challenge to utilities as the high energy demand from this industry can overburden the existing utility infrastructure. Hence, from both planning and operational perspectives, it is crucial to understand the energy consumption of the rapidly growing load. This paper proposes a deterministic energy consumption model for indoor cannabis cultivation operations for the two major loads in these facilities, i.e., lighting and HVAC, over a 24-hour period based on equipment specifications and operational requirements of the facility. This model can further be used to estimate or forecast short-term and long-term energy demands and costs of indoor cannabis operation(s). The proposed model successfully simulated the environmental conditions in a real-world cannabis facility, and the model's energy consumption output is validated using actual measurements taken from this facility as well as model output using GridLab-D.
Influence of Heliolatitudinal Anisotropy of Solar FUV/EUV Emissions on Lyman-alpha Helioglow: SOHO/SWAN Observations and WawHelioGlow Modeling
Creators: name: Strumik, Marek
name: Bzowski, Maciej
name: Kubiak, Marzena A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Observations of the Sun's surface suggest a nonuniform radiated flux as related to the presence of bright active regions and darker coronal holes. The variations of the FUV/EUV source radiation can be expected to affect the Lyman-alpha backscatter glow measured by spaceborne instruments. In particular, inferring the heliolatitudinal structure of the solar wind from helioglow variations in the sky can be quite challenging if the heliolatitudinal structure of the solar FUV/EUV radiation is not properly included in the modeling of the heliospheric glow. We present results of analysis of the heliolatitudinal structure of the solar Lyman-alpha radiation as inferred from comparison of SOHO/SWAN satellite observations of the helioglow intensity with modeling results obtained from the recently-developed WawHelioGlow model. We find that in addition to time-dependent heliolatitudinal anisotropy of the solar wind, also time-dependent heliolatitudinal variations of the intensity of the solar Lyman-alpha and photoionizing emissions must be taken into account to reproduce the observed helioglow modulation in the sky. We present a particular latitudinal and temporal dependence of the solar Lyman-alpha flux obtained as a result of our analysis. We analyze also differences between polar-equatorial anisotropies close to the solar surface and seen by an observer located far from the Sun. We discuss the implications of these findings for the interpretation of heliospheric-glow observations.
description: Accepted for publication in Astrophysical Journal Letters, 11 pages, 5 figures
title:  Another Look at the City: Emphasizing Temporality in Urban Aesthetics
Creators: name: Lehtinen  , Sanna
Publisher: name: Roma TrE-Press
Year: 2021

description: Cities are usually formed over long periods of time. The subjective experience of time on the scale of a human individual comes together with the longer lifespan of human made constructions in contemporary cities. Intergenerational aesthetic values are negotiated together with short-term trends and both have an influence on how cities become perceived, experienced, and used. Changes in the material conditions define the aesthetic qualities of urban environments. Building, demolition, and acts of care and maintenance are needed to keep the material system of the city functioning. The forms of urban structures draw direct aesthetic attention as they are being designed and redesigned in these processes. Buildings and architecture as such have for long carried meanings beyond the mere function of giving shelter. Building materials, for example, prove to be a central source of new meanings as they are currently being re-evaluated from the perspective of ecological and sustainability values. This article outlines how philosophical urban aesthetics can take into account the explicit aspects of aesthetic value change in cities. The article shows how the idea of aesthetic sustainability could be introduced into urban aesthetics in a way that will increase our understanding of how aesthetics and sustainability are and could further be interlinked in contemporary and future urban environments.
description: Everydayness. Contemporary Aesthetic Approaches
System Protection and Voltage Stability
Creators: Working Group K12 Protection Aids to Voltage Stability
Publisher: name: IEEE
Year: 1993

This special report was prepared by the Protection Aids to Voltage Stability Working Group of the Substation Protection Subcommittee. At the time the report was submitted for approval, May, 1993, the Working Group membership consisted of M. Begovic, D. Fulton, M.R. Gonzalez, J. Goossens, E.A. Guro, R.W. Haas, C.F. Henville, G. Manchur, G.L. Michel, R.C. Pastore, J. Postforoosh, G.L. Schmitt, J.B. Williams, K. Zimmerman. Contributions from former Working Group member A.A. Burzese are also acknowledged.
This special report was prepared by the Protection Aids to Voltage Stability Working Group of the Substation Protection Subcommittee. At the time the report was submitted for approval, May, 1993, the Working Group membership consisted of M. Begovic, D. Fulton, M.R. Gonzalez, J. Goossens, E.A. Guro, R.W. Haas, C.F. Henville, G. Manchur, G.L. Michel, R.C. Pastore, J. Postforoosh, G.L. Schmitt, J.B. Williams, K. Zimmerman. Contributions from former Working Group member A.A. Burzese are also acknowledged.
Benchmarking the Status of Agricultural Mechanization in Ethiopia
Creators: name: Deribe, Yared
name: Getnet, Bisrat
name: G.Kang, Tae
name: Tesfaye, Agajie
Publisher: name: figshare
Year: 2021
Subjects: subject: 140201 Agricultural Economics
subject: FOS: Economics and business
subject: 99901 Agricultural Engineering
subject: FOS: Other engineering and technologies
subject: 70307 Crop and Pasture Post Harvest Technologies (incl. Transportation and Storage)
subject: FOS: Agriculture, forestry and fisheries

description: The study generates baseline information on farmers’ access and utilization of agricultural mechanization practices in the crop and livestock production systems. It comprises the determination of the level or index of mechanization in the pre and post-harvest stages of farm operations. The key challenges that the farm machinery importers, manufacturers, and hiring service operators are facing has been dealt.
Turbine Startup and Shutdown in Wind Farms Featuring Partial Power Processing Converters
Creators: Marten Pape and Mehrdad Kazerani
Publisher: name: IEEE
Year: 2020

In this paper, the startup and shutdown procedures for a series-dc wind farm featuring diode-bridge rectifiers and partial power processing converters as wind turbine converters, are investigated and constraints on converter ratings are evaluated.
The wind turbine startup and shutdown procedures for electrical subsystems are straightforward for wind turbines featuring full-scale power electronic converters and have not required significant attentions from the research community. However, for offshore wind farms featuring series-connected dc collection systems and differential power processing capabilities, the controllable wind turbine power converters might not be rated in such a way that a full-scale output power difference can be handled within a series string. As startup and shutdown procedures can require a transition from zero to full power, a more elaborate design is required to ensure that wind turbines can still start and stop reliably under all conditions, without compromising advantages in reduced wind turbine converter ratings with differential power processing capabilities. In this paper, the startup and shutdown procedures for a series-dc wind farm featuring diode-bridge rectifiers and partial power processing converters as wind turbine converters, are investigated and constraints on converter ratings are evaluated.