cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
CFD Analysis of a Rail Way Tunnel Ventilation
Creators: name: Aberahm, Berhanu
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2016

description: The aim of a tunnel ventilation system is to reach the major safety levels as possible both in fire and service situations. In service situation the system has to guarantee that the atmosphere of the tunnel assembles a suitable condition of comfort and safety for the users; assuring the dilution of the pollutants from the vehicles to admissible limits, and allowing a suitable reaction capacity in case of a quick demand of flow. On the other hand, in case of fire the aims would be to control the smoke layer as far from the users as possible, to avoid the spreading of the incident to zones not implied in the fire and to support in rescue tasks. ANSYS FLUENT is Computational Fluid Dynamics (CFD) software that allows users to simulate flow problems of ranging complexity. It contains broad physical modeling capabilities needed to model flow, turbulence, heat transfer, and reactions over objects designed by the user. In this thesis the objective of the study is to analyze the rail way tunnel ventilation system using CFD software to create comfort ventilation system in the tunnel. The comfort ventilation concept refers to the situation when air quality within the tunnel is reduced due to presence of polluted air in the tunnel. Based on the conditions on, Mekele tunnel numerical analysis of air flow field is carried out by the finite element software—CFD and k-ɛ turbulence model to show the volume flow rate of the expelled air out of the tunnel by using jet fans in this paper.The result shows that the required amount of air is removed by using a series arrangement of jet fans to create the comfort ventilation system in the tunnel.
On the Link Between Energy Equipartition and Radial Variation in the Stellar Mass Function of Star Clusters
Creators: name: Webb, Jeremy J.
name: Vesperini, Enrico
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We make use of $N$-body simulations to determine the relationship between two observable parameters that are used to quantify mass segregation and energy equipartition in star clusters. Mass segregation can be quantified by measuring how the slope of a cluster's stellar mass function $α$ changes with clustercentric distance r, and then calculating $δ_α= \frac{d α(r)}{d ln(r/r_m)}$ where $r_m$ is the cluster's half-mass radius. The degree of energy equipartition in a cluster is quantified by $η$, which is a measure of how stellar velocity dispersion $σ$ depends on stellar mass m via $σ(m) \propto m^{-η}$. Through a suite of $N$-body star cluster simulations with a range of initial sizes, binary fractions, orbits, black hole retention fractions, and initial mass functions, we present the co-evolution of $δ_α$ and $η$. We find that measurements of the global $η$ are strongly affected by the radial dependence of $σ$ and mean stellar mass and the relationship between $η$ and $δ_α$ depends mainly on the cluster's initial conditions and the tidal field. Within $r_m$, where these effects are minimized, we find that $η$ and $δ_α$ initially share a linear relationship. However, once the degree of mass segregation increases such that the radial dependence of $σ$ and mean stellar mass become a factor within $r_m$, or the cluster undergoes core collapse, the relationship breaks down. We propose a method for determining $η$ within $r_m$ from an observational measurement of $δ_α$. In cases where $η$ and $δ_α$ can be measured independently, this new method offers a way of measuring the cluster's dynamical state.
description: 9 pages, 5 figures, 2 tables, Accepted for publication in MNRAS
Mechanical thermal expression : characterisation and modelling of the compression mechanism
Creators: name: Wheeler., Rory Alexander
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Power Line Communication Based Real Time Train Tracking System for Addis Ababa Light Rail Transit
Creators: name: Solomon, Firew
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2015

description: In railway traffics the low friction between wheel and rail causes long braking distances, normally much longer than the driver"s sight distance, i.e. if the driver starts the braking when he discovers a problem on the track it is too late to stop the train. The conclusion will be that the railway traffic can not only rely on the driver for the traffic safety, there must also be a signaling or even an automatic surveyor system, which can supervise the positions of different trains along the track and organize the traffic. Having the traffics information on the track helps to avoid situations of conflict and those that might be potentially unsafe. There are different train detection systems in service worldwide. Track circuit, Axle counter and GPS are the most prevailed approaches. The first two types provide the information that whether the section is occupied or not. They don"t provide the information "where exactly the train is?" Beside Axle counter has huge installation cost and maintenance cost. Regarding GPS, since it is using satellites to determine the location of the train and the accuracy is dependent on the no of satellites tracked, the error spread is variable. In addition to this it doesn"t operate in tunnels like we have for A.A LRT (Addis Ababa Light Rail Transit) track, from St. George church to Atikilit tera. Not only these but also since the satellites are administered by third party, the operation is totally out of the control of the railway company. With this research, Power line based real-time train tracking system is proposed for A.A LRT. It has an advantage of providing continuous distance information, low capital cost, low maintenance cost and under a full control of Railway Company. Since it uses the power line communication, the channel is secured since the train is on the track and the overhead contact system exists. Beside of the train detection software is developed to display visually the train movement according to the distance information obtained. The system can also extend to broadcasting the information obtained via a possible communication means (GSM-R) to control center or other trains on the track. This increases the movement confidence of the trains since the driver operates with the knowledge of distance, direction and speed of trains at the back and front that helps a lot for efficient use of the track.
Integrated Urban Drainage System; the Case of Ayat to Megenagna Light Rail Transit Route
Creators: name: Anteneh, Zewdu
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2015

description: Addis Ababa is one of the fastest growing cities in Africa and urbanization is known to increase the amount of runoff generated from the urban catchment. Due to urbanization and lack of proper design and management, the cities transport infrastructure has experienced frequent flooding. The application of Integrated Sustainable Urban Drainage System (SUDS) is a recent trend in developed countries (like the UK) for flood mitigation with added benefit of amenity and water quality. The aim of this study was to assess SUDS applicability in solving the existing drainage problem and minimizing the flood risk associated to transport infrastructure. In this study Ayat to Megenagna section of the Addis Ababa Light Railway Transit (LRT) line was chosen as a study area. Areas along the route with drainage problems have been identified and catchment was delineated. IDF curves were developed and rational method was used to estimate the existing runoff. Rooftop rainwater harvesting and rain gardens were proposed to solve the drainage problem. A tool that uses daily rainfall records of 30 years is developed in Microsoft Excel to quantify the amount of runoff reduction that can be achieved by using SUDS. The tool calculates the percentage of runoff that can be intercepted using a given storage capacity of rainwater harvesting system for a given daily non potable water demand. The tool is developed in such a way that allows modelling of different demand and storage size scenario. The result is presented in terms of a typical 90 square meters' parcel found in the study area of which 89% is covered with roof area and 11% with rain garden. For daily non potable water demand of 257 liters it is found that the optimum storage tank capacity is 1500 liters. Using a tank of 1500 liters' storage capacity, the percent reduction in runoff that can be achieved is found to be 51% of runoff generated from rainfall of 2cm or less depth. This shows that considerable runoff reduction can be achieved using rainwater harvesting and rainwater gardening. These study shows that integrated sustainable drainage systems can be used to protect transport infrastructure along Ayat to Megenagna route and the author recommends further detailed study and implementation.
Our Sky now and then $-$ searches for lost stars and impossible effects as probes of advanced extra-terrestrial civilisations
Creators: name: Villarroel, Beatriz
name: Imaz, Iñigo
name: Bergstedt, Josefine
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Searches for extra-terrestrial intelligence (SETI) using large survey data often look for possible signatures of astroengineering. We propose to search for physically impossible effects caused by highly advanced technology, by carrying out a search for disappearing galaxies and Milky Way stars. We select $\sim$ 10 million objects from USNO-B1.0 with low proper motion ($μ$ $
description: Accepted to the Astronomical Journal
Gravitational wave observations may constrain gamma-ray burst models: the case of GW 150914 - GBM
Creators: name: Veres, P.
name: Preece, R. D.
name: Goldstein, A.
name: Mészáros, P.
name: Burns, E.
name: Connaughton, V.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The possible short gamma-ray burst (GRB) observed by {\it Fermi}/GBM in coincidence with the first gravitational wave (GW) detection, offers new ways to test GRB prompt emission models. Gravitational wave observations provide previously unaccessible physical parameters for the black hole central engine such as its horizon radius and rotation parameter. Using a minimum jet launching radius from the Advanced LIGO measurement of GW~150914, we calculate photospheric and internal shock models and find that they are marginally inconsistent with the GBM data, but cannot be definitely ruled out. Dissipative photosphere models, however have no problem explaining the observations. Based on the peak energy and the observed flux, we find that the external shock model gives a natural explanation, suggesting a low interstellar density ($\sim 10^{-3}$ cm$^{-3}$) and a high Lorentz factor ($\sim 2000$). We only speculate on the exact nature of the system producing the gamma-rays, and study the parameter space of a generic Blandford Znajek model. If future joint observations confirm the GW-short GRB association we can provide similar but more detailed tests for prompt emission models.
description: 10 pages, 4 figures, minor additions, ApJL accepted
Floquet prethermalization and regimes of heating in a periodically driven, interacting quantum system
Creators: name: Weidinger, Simon A.
name: Knap, Michael
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the regimes of heating in the periodically driven $O(N)$-model, which represents a generic model for interacting quantum many-body systems. By computing the absorbed energy with a non-equilibrium Keldysh Green's function approach, we establish three dynamical regimes: at short times a single-particle dominated regime, at intermediate times a stable Floquet prethermal regime in which the system ceases to absorb, and at parametrically late times a thermalizing regime. Our simulations suggest that in the thermalizing regime the absorbed energy grows algebraically in time with an the exponent that approaches the universal value of $1/2$, and is thus significantly slower than linear Joule heating. Our results demonstrate the parametric stability of prethermal states in a generic many-body system driven at frequencies that are comparable to its microscopic scales. This paves the way for realizing exotic quantum phases, such as time crystals or interacting topological phases, in the prethermal regime of interacting Floquet systems.
description: 4+4 pages, 3+3 figures
Monte-Carlo study of Dirac semimetals phase diagram
Creators: name: Braguta, V. V.
name: Katsnelson, M. I.
name: Kotov, A. Yu.
name: Nikolaev, A. A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: In this paper the phase diagram of Dirac semimetals is studied within lattice Monte-Carlo simulation. In particular, we concentrate on the dynamical chiral symmetry breaking which results in semimetal/insulator transition. Using numerical simulation we determined the values of the critical coupling constant of the semimetal/insulator transition for different values of the anisotropy of the Fermi velocity. This measurement allowed us to draw tentative phase diagram for Dirac semimetals. It turns out that within the Dirac model with Coulomb interaction both Na$_3$Bi and Cd$_3$As$_2$ known experimentally to be Dirac semimetals would lie deeply in the insulating region of the phase diagram. It probably shows a decisive role of screening of the interelectron interaction in real materials, similar to the situation in graphene.
description: 5 pages, 5 figures
Analyzing Addis Ababa Light Rail Transit Railway Operation Reliability
Creators: name: Abdourahman, Omar Hassan
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2017

description: Delays in railway networks cause problems in the daily operation and result in reduced reliability of the railway operation. Since the delay is not caused only by the overcrowded train schedules but also the congestion at railway stations during the peak hours. In fact the determination of train dwell time is an essential step in planning railway timetable with taking the passengers' experience into account. In view of that, this research focuses on describing how it is possible to use passenger flow to estimate the actual delays on Addis Ababa LRT. The combination of the passenger flow on dwell time and the headway of a train is described, the research methodology adopt a strategy to estimate these paramaters to consider various kinds of improvement and demonstrating the possibility of predicting an eventual decreasing the delay of the trip and by the same time satisfy the customers. The result demonstrated that using together between dwell time and headway time to analyse the reliability of AALRT have given a benefit return concerning about the delay caused but the daily operation.. Finally, as the proposed investigated method is relatively easy to implement based on collection passengers flow data, the contributions from the outcomes of these models are briefly addressed.
Phase transformations in near-eutectoid titanium-nickel alloys
Creators: name: Wexler., David
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
ATLASGAL-selected massive clumps in the inner Galaxy III. Dust Continuum Characterization of an Evolutionary Sample
Creators: name: König, C.
name: Urquhart, J. S.
name: Csengeri, T.
name: Leurini, S.
name: Wyrowski, F.
name: Giannetti, A.
name: Wienen, M.
name: Pillai, T.
name: Kauffmann, J.
name: Menten, K. M.
name: Schuller, F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The ATLASGAL survey provides an ideal basis for detailed studies of large numbers of massive star forming clumps covering the whole range of evolutionary stages. The ATLASGAL Top100 is a sample of clumps selected from their infrared and radio properties to be representative for the whole range of evolutionary stages. The ATLASGAL Top100 sources are the focus of a number of detailed follow-up studies that will be presented in a series of papers. In the present work we use the dust continuum emission to constrain the physical properties of this sample and identify trends as a function of source evolution. We determine flux densities from mid-infrared to submm wavelength (8-870 micron) images and use these values to fit their spectral energy distributions (SEDs) and determine their dust temperature and flux. Combining these with recent distances from the literature including maser parallax measurements we determine clump masses, luminosities and column densities. We find trends for increasing temperature, luminosity and column density with the proposed evolution sequence, confirming that this sample is representative of different evolutionary stages of massive star formation. We show that most of the sample has the ability to form massive stars (including the most massive O-type stars) and that the majority is gravitationally unstable and hence likely to be collapsing. The highest column density ATLASGAL sources presented cover the whole range of evolutionary stages from the youngest to the most evolved high-mass star forming clumps. Their study provides a unique starting point for more in-depth research on massive star formation in four distinct evolutionary stages whose well defined physical parameters afford more detailed studies. As most of the sample is closer than 5 kpc, these sources are also ideal for follow-up observations with high spatial resolution.
description: 20 pages, 14 figures, 5 tables, accepted for publication in A&A
title: Phosphorylation of LKB1 by PDK1 Inhibits Cell Proliferation and Organ Growth by Decreased Activation of AMPK
Creators: name: Borkowsky, Sarah
name: Gass, Maximilian
name: Alavizargar, Azadeh
name: Hanewinkel, Johannes
name: Hallstein, Ina
name: Nedvetsky, Pavel I.
name: Heuer, Andreas
name: Krahn, Michael Peter Rolf
Publisher: name: University of Muenster, Institutional Repository MIAMI
Year: 2023
Subjects: subject: 610 Medicine and health

description: The master kinase LKB1 is a key regulator of several cellular processes, including cell proliferation, cell polarity and cellular metabolism. It phosphorylates and activates several downstream kinases, including AMP-dependent kinase, AMPK. Activation of AMPK by low energy supply and phosphorylation of LKB1 results in an inhibition of mTOR, thus decreasing energy-consuming processes, in particular translation and, thus, cell growth. LKB1 itself is a constitutively active kinase, which is regulated by posttranslational modifications and direct binding to phospholipids of the plasma membrane. Here, we report that LKB1 binds to Phosphoinositide-dependent kinase (PDK1) by a conserved binding motif. Furthermore, a PDK1-consensus motif is located within the kinase domain of LKB1 and LKB1 gets phosphorylated by PDK1 in vitro. In Drosophila, knockin of phosphorylation-deficient LKB1 results in normal survival of the flies, but an increased activation of LKB1, whereas a phospho-mimetic LKB1 variant displays decreased AMPK activation. As a functional consequence, cell growth as well as organism size is decreased in phosphorylation-deficient LKB1. Molecular dynamics simulations of PDK1-mediated LKB1 phosphorylation revealed changes in the ATP binding pocket, suggesting a conformational change upon phosphorylation, which in turn can alter LKB1's kinase activity. Thus, phosphorylation of LKB1 by PDK1 results in an inhibition of LKB1, decreased activation of AMPK and enhanced cell growth.
Optimizing Traffic Network around Grade Crossing for the Case of AALRT
Creators: name: Tibebu, Tiruneh
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2016

description: The existing public transport system in Addis Ababa is critically insufficient to provide service for the existing travel demand. Public transportation is one and the most important means of easing traffic congestion for it makes roads work better by reducing the number of vehicles on the road. This shows that a great concern should go towards the expansion of high- capacity public transportation system like introduction of light rail, heavy rail, road bus transit, and high occupancy vehicles lanes, which coupled with better management of the existing road network and traffic management. We need therefore to have a clearly defined transport management technology to challenge the mobility issues of the city. Grade Crossing is a location where a public highway, road, street, or private roadway, including associated sidewalks, and pathways, crosses railroad tracks at grade (same level as the street).The aim of this thesis is to encourage grade crossing safety and reduce highway traffic delay. The safety of grade crossing can be promoted by removing those vehicles detected on the railroad tracks before the arrival of trains using CCTV camera by image processing technology. Reduce highway traffic delay by proper managing the phase sequence of the intersection. A system model is proposed and developing with the system. The optimization will be implemented into two steps. The first step, the delay function is approximated and represented by artificial neural network. Secondly optimization will be applied based on Levenberg-Marquardt optimization. We use different approach, instead of protecting grade crossing manually and showing the hostility to the highway drivers, we could develop an advanced traffic management system smart enough to control the traffic near grade crossings. In such a system, we could incorporate grade crossing information into traffic control and prevent the queue from backing onto the railroad tracks. Preemption of the traffic signal at/near a grade crossing is such an alternative to target safety improvement. Artificial neural network is design for both train arrival time at grade crossing and forecasting of traffic signal phase length at intersection. MATLAB programing is applied for the designs simulation. From the simulation result the network is optimized by decreasing MSE of train arrival time and traffic signal phase length prediction by 2.2696x10-19 and 8.338x10-9 respectively. Image processing is applied for obstacle detections on grade crossing by the concept of image segmented in matrix form.
From asymptotic freedom toward heavy quarkonia within the renormalization group procedure for effective particles
Creators: name: Gómez-Rocha, María
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The renormalization group procedure for effective particles (RGPEP), developed as a nonperturbative tool for constructing bound states in quantum field theories, is applied to QCD. The approach stems from the similarity renormalization group and introduces the concept of effective particles. It has been shown that the RGPEP passes the test of exhibiting asymptotic freedom. We present the running of the Hamiltonian coupling with the renormalization-group scale and summarize the basic elements needed in the formulation of the bound-state problem.
description: Presented at Light Cone 2016, IST, Universidade de Lisboa, Portugal, September 5-8 2016. 8 pages, 3 figures
Homogeneous kinetics of cyclohexane oxidation
Creators: name: Wen., Yu
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Cosmology with AGN dust time lags -- Simulating the new VEILS survey
Creators: name: Hönig, S. F.
name: Watson, D.
name: Kishimoto, M.
name: Gandhi, P.
name: Goad, M.
name: Horne, K.
name: Shankar, F.
name: Banerji, M.
name: Boulderstone, B.
name: Jarvis, M.
name: Smith, M.
name: Sullivan, M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The time lag between optical and near-infrared continuum emission in active galactic nuclei (AGN) shows a tight correlation with luminosity and has been proposed as a standardisable candle for cosmology. In this paper, we explore the use of these AGN hot-dust time lags for cosmological model fitting under the constraints of the new VISTA Extragalactic Infrared Legacy Survey VEILS. This new survey will target a 9 deg^2 field observed in J- and Ks-band with a 14-day cadence and will run for three years. The same area will be covered simultaneously in the optical griz bands by the Dark Energy Survey, providing complementary time-domain optical data. We perform realistic simulations of the survey setup, showing that we expect to recover dust time lags for about 450 objects out of a total of 1350 optical type 1 AGN, spanning a redshift range of 0.1 < z < 1.2. We use the lags recovered from our simulations to calculate precise distance moduli, establish a Hubble diagram, and fit cosmological models. Assuming realistic scatter in the distribution of the dust around the AGN as well as in the normalisation of the lag-luminosity relation, we are able to constrain Ω_Λ in ΛCDM with similar accuracy as current supernova samples. We discuss the benefits of combining AGN and supernovae for cosmology and connect the present work to future attempts to reach out to redshifts of z > 4.
description: 12 pages, 6 figures, 2 tables. MNRAS in press
Driven Discrete Time Quantum Walks
Creators: name: Hamilton, Craig S.
name: Barkhofen, Sonja
name: Sansoni, Linda
name: Jex, Igor
name: Silberhorn, Christine
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We introduce the driven discrete time quantum walk, where walkers are added during the walk instead of only at the beginning. This leads to interference in walker number and very different dynamics when compared to the original quantum walk. These dynamics have two regimes, which we illustrate using the one-dimensional line. Then, we explore a search application which has certain advantages over current search protocols, namely that it does not require a complicated initial state nor a specific measurement time to observe the marked state. Finally, we describe a potential experimental implementation using existing technology.
description: accepted for publication in NJP
Two Distinct-Absorption X-Ray Components from Type IIn Supernovae: Evidence for Asphericity in the Circumstellar Medium
Creators: name: Katsuda, Satoru
name: Maeda, Keiichi
name: Bamba, Aya
name: Terada, Yukikatsu
name: Fukazawa, Yasushi
name: Kawabata, Koji
name: Ohno, Masanori
name: Sugawara, Yasuharu
name: Tsuboi, Yohko
name: Immler, Stefan
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present multi-epoch X-ray spectral observations of three Type IIn supernovae (SNe) 2005kd, 2006jd, and 2010jl, acquired with Chandra, XMM-Newton, Suzaku, and Swift. Previous extensive X-ray studies of SN 2010jl have revealed that X-ray spectra are dominated by thermal emission, which likely arises from a hot plasma heated by a forward shock propagating into a massive circumstellar medium (CSM). Interestingly, an additional soft X-ray component was required to reproduce the spectra at a period of ~1-2 yr after the SN explosion. Although this component is likely associated with the SN, its origin remained an open question. We find a similar, additional soft X-ray component from the other two SNe IIn as well. Given this finding, we present a new interpretation for the origin of this component; it is thermal emission from a forward shock essentially identical to the hard X-ray component, but directly reaches us from a void of the dense CSM. Namely, the hard and soft components are responsible for the heavily- and moderately-absorbed components, respectively. The co-existence of the two components with distinct absorptions as well as the delayed emergence of the moderately-absorbed X-ray component would be evidence for asphericity of the CSM. We show that the X-ray spectral evolution can be qualitatively explained by considering a torus-like geometry for the dense CSM. Based on our X-ray spectral analyses, we estimate the radius of the torus-like CSM to be on the order of ~5 times 10^{16} cm.
description: 11 pages, 3 figures, accepted for publication in The Astrophysical Journal
Approximate Furthest Neighbor with Application to Annulus Query
Creators: name: Pagh, Rasmus
name: Silvestri, Francesco
name: Sivertsen, Johan
name: Skala, Matthew
Publisher: name: arXiv
Year: 2016
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: FOS: Computer and information sciences

description: Much recent work has been devoted to approximate nearest neighbor queries. Motivated by applications in recommender systems, we consider approximate furthest neighbor (AFN) queries and present a simple, fast, and highly practical data structure for answering AFN queries in high- dimensional Euclidean space. The method builds on the technique of In- dyk (SODA 2003), storing random projections to provide sublinear query time for AFN. However, we introduce a different query algorithm, improving on Indyk's approximation factor and reducing the running time by a logarithmic factor. We also present a variation based on a query- independent ordering of the database points; while this does not have the provable approximation factor of the query-dependent data structure, it offers significant improvement in time and space complexity. We give a theoretical analysis, and experimental results. As an application, the query-dependent approach is used for deriving a data structure for the approximate annulus query problem, which is defined as follows: given an input set S and two parameters r > 0 and w >= 1, construct a data structure that returns for each query point q a point p in S such that the distance between p and q is at least r/w and at most wr.
Fibre optic chemical sensors and systems
Creators: name: Welti., Neal Arthur
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Scheduling Distributed Clusters of Parallel Machines: Primal-Dual and LP-based Approximation Algorithms [Full Version]
Creators: name: Murray, Riley
name: Khuller, Samir
name: Chao, Megan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: FOS: Computer and information sciences
subject: F.2.2

description: The Map-Reduce computing framework rose to prominence with datasets of such size that dozens of machines on a single cluster were needed for individual jobs. As datasets approach the exabyte scale, a single job may need distributed processing not only on multiple machines, but on multiple clusters. We consider a scheduling problem to minimize weighted average completion time of N jobs on M distributed clusters of parallel machines. In keeping with the scale of the problems motivating this work, we assume that (1) each job is divided into M "subjobs" and (2) distinct subjobs of a given job may be processed concurrently. When each cluster is a single machine, this is the NP-Hard concurrent open shop problem. A clear limitation of such a model is that a serial processing assumption sidesteps the issue of how different tasks of a given subjob might be processed in parallel. Our algorithms explicitly model clusters as pools of resources and effectively overcome this issue. Under a variety of parameter settings, we develop two constant factor approximation algorithms for this problem. The first algorithm uses an LP relaxation tailored to this problem from prior work. This LP-based algorithm provides strong performance guarantees. Our second algorithm exploits a surprisingly simple mapping to the special case of one machine per cluster. This mapping-based algorithm is combinatorial and extremely fast. These are the first constant factor approximations for this problem.
description: A shorter version of this paper (one that omitted several proofs) appeared in the proceedings of the 2016 European Symposium on Algorithms
Beyond the Maltese cross: geometry of turbulence between 0.2 and 1 AU
Creators: name: Verdini, Andrea
name: Grappin, Roland
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The spectral anisotropy of turbulent structures has been measured in the solar wind since 1990, relying on the assumption of axisymmetry about the mean magnetic field, B0. However, several works indicate that this hypothesis might be partially wrong, thus raising two questions: (i) is it correct to interpret measurements at 1 AU (the so-called Maltese cross) in term of a sum of slab and 2D turbulence? (ii) what information is really contained in the Maltese cross? We solve direct numerical simulations of the MHD equations including the transverse stretching exerted by the solar wind flow and study the genuine 3D anisotropy of turbulence as well as that one resulting from the assumption of axisymmetry about B0. We show that the evolution of the turbulent spectrum from 0.2 to 1 AU depends strongly on its initial anisotropy. An axisymmetric spectrum with respect to B0 keeps its axisymmetry, i.e., resists stretching perpendicular to radial, while an isotropic spectrum becomes essentially axisymmetric with respect to the radial direction. We conclude that close to the Sun, slow-wind turbulence has a spectrum that is axisymmetric around B0 and the measured 2D component at 1 AU describes the real shape of turbulent structures. On the contrary, fast-wind turbulence has a more isotropic spectrum at the source and becomes radially symmetric at 1 AU. Such structure is hidden by the symmetrization applied to the data that instead returns a slab geometry.
description: 8 pages, 8 figures, accepted for publication in ApJ
title: A case of lipomatous hypertrophy of interatrial septum
Creators: name: Singh, Ankit
Publisher: name: EURORAD
Year: 2022
Subjects: subject: Cardiovascular
subject: Anatomy
subject: Cardiovascular system
subject: Anatomy
subject: Cardiovascular system
subject: Anatomy and Functional Imaging

description: Clinical History: A CT thorax, abdomen and pelvis was performed for a 73-year-old lady with a history of dyspepsia and possible mass appearance on gastroscopy. An incidental finding of a hypodense mass adjacent to the right atrium was made.

description: 73 years, female
Development of Adaptive Control for Railway Vehicles Braking System: Case study for AA-LRT
Creators: name: Yared, Kassahu
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2017

description: Since railway transport is one of the main modes of land transportation, stopping rail vehicles at stations is the eventual routine of the service. The critical challenge in railway vehicles braking system is accurately limiting train braking distance under different operation conditions, since the train movement is on metal rail with low adhesion coefficient relative to road lines. Accurate estimation of the braking distance will allow trains to be spaced closer together, with reasonable confidence that they will stop without colliding each other. Therefore, a dedicated braking control system is intensely required, which can enhance fast and reliable control actions. Currently trams used in Addis Ababa Light Rail Transit equipped with Proportional and Integral controller based closed loop Variable Voltage Variable Frequency drive system. The conventional Proportional and Integral controller with fixed gain and normal feedback is unable to achieve desired braking control performance under different disturbances. The motive of this work is to investigate the existing train braking control system and develop a new adaptive control mechanism that can handle disturbances and gives adequate control response. Model reference adaptive controller tunes a given proportional and integral controller in such a way that error between the speed command and actual speed will be minimized to improve braking control action. A well-known Massachusetts Institute of Technology (gradient) adaptation algorithm is used to develop the proposed adaptive control system. The existing and the newly developed control systems are compared using MathLab environment. According to the simulation results for disturbance handling model reference adaptive system has 1.504 % overshoot and 1.876 rad/sec speed error which is much smaller than proportional and integral controller with 92.7 % overshoot and 6.26 rad/sec speed error. Also model reference adaptive controller significantly improved braking distance and time around 25% more than proportional and integral controller by giving fast response.
Pseudo-3D animations using 2D image morphing techniques
Creators: name: Welsh., Stephen
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Modeling the low-carbon transition of the European energy system - A quantitative assessment of the stranded assets problem
Creators: name: Löffler, Konstantin
name: Burandt, Thorsten
name: Hainsch, Karlo
name: Oei, Pao-Yu
Publisher: name: Technische Universität Berlin
Year: 2019
Subjects: subject: 333 Boden- und Energiewirtschaft
subject: 620 Ingenieurwissenschaften und zugeordnete Tätigkeiten
subject: decarbonization
subject: energy policy
subject: energy system modeling
subject: energy transition
subject: GENeSYS-MOD
subject: renewables
subject: stranded assets

description: In this paper, multiple pathways for the European energy system until 2050 are computed, focusing on one of the major challenges of the low-carbon transition: the issue of unused capacities and stranded assets. Three different scenarios are analyzed, utilizing the Global Energy System Model (GENeSYS-MOD) for calculations. A major feature is the introduction of limited foresight and imperfect planning to the multi-sectoral approach of the model. A swift transition towards renewable energy sources is needed in order to ensure the goal of staying below 2 °C is maintained. This leads to the underutilization of current fossil-fueled plant capacities, an effect compounded by the prioritization of short-term goals over long-term targets. In the worst case, capacities with a combined value of up to 200 billion € corresponding to 260 GW total capacity may end up stranded by 2035, with significant shares in the coal and gas sectors. Contrary, in the baseline scenario featuring perfect foresight, this amount can by reduced by as much as 75%. Thus, the need for strong, clear signals from policy makers arises in order to combat the threat of short-sighted planning and investment losses.
Modeling and Analyzing the Deformation of Ballast Structure Due to Repetition of Loads
Creators: name: Shimelis, Assefa
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2015

description: The issue of permanent deformation of ballast structure due to repetition of loads is the most important element in railway maintenance planning and policy making. It affects the general operation and management of railway transportation plus the overall costs of track structure and its life spans. To allow a safe, reliable and efficient rail network and to provide a good ride quality, the vertical profile of a railway track has to be maintained at a satisfactory level. And timely maintenance of ballast structure is essential to provide continuous service at reasonable costs since the track permanent deformation is a function of traffic load, environmental condition and track structure response behavior to the applied loads at different times of service life. Although most of the time deterioration process is very slow, but it might lead to massive failures with an enormous financial lose. This research determines the permanent deformation of railway ballast, particularly the vertical settlement under repeated traffic loading. Experimental data reviewed in the literature were assumed to represent the ballast materials used in LRT projects. After initial elastic modeling, the extended Drucker-Prager model with hardening, which simulates the initial plastic deformation of granular materials under cyclic loads, were used in the FEM analysis in order to account for the inelastic behavior of railway ballast. Besides, FEM analysis provides the information to predict railway ballast deformation in terms of number of loading under wheel loading. And it can be observed that the vertical stresses were concentrated underneath the sleeper and ballast permanent deformation is increasing exponentially with increasing number of loading cycles and deform non- linearly with increasing depths of ballast.
Analysis of a Frequency-Hopping Millimeter-Wave Cellular Uplink
Creators: name: Torrieri, Don
name: Talarico, Salvatore
name: Valenti, Matthew C.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Fifth-generation (5G) cellular networks are expected to exhibit at least three primary physical-layer differences relative to fourth-generation ones: millimeter-wave propagation, massive antenna arrays, and densification of base stations. As in fourth-generation systems, such as LTE, 5G systems are likely to continue to use single-carrier frequency division multiple-access (SC-FDMA) on the uplink due to its advantageous peak-to-average power ratio. Moreover, 5G systems are likely to use frequency hopping on the uplink to help randomize interference and provide diversity against frequency-selective fading. In this paper, the implications of these and other physical-layer features on uplink performance are assessed using a novel millimeter-wave propagation model featuring distance-dependent parameters that characterize the path-loss, shadowing, and fading. The analysis proceeds by first fixing the location of the mobile devices and finding the performance conditioned on the topology. The spatially averaged performance is then found by averaging with respect to the location of the mobile devices. The analysis allows for the use of actual base-station topologies and the propagation model can leverage empirical millimeter-wave measurements. The benefits of base-station densification, highly directional sectorization, frequency hopping, a large available bandwidth, and a high code rate are illustrated. The minor importance of fractional power control is shown.
description: 24 pages, 10 figures, 1 Table, 23 references, accepted to IEEE Transactions on Wireless Communications
The Outdoor Type
Creators: name: Washington, Katrina Renee
Publisher: name: University of Illinois at Chicago
Year: 2023

description: The novel manuscript, The Outdoor Type, explores the trauma of imposed motherhood on women. The protagonist, Claire, is a woman begrudgingly transitioning into motherhood after her husband’s first wife is diagnosed with cancer and subsequently dies, leaving behind a teen daughter. While making a statement about motherhood’s assumed proximity to womanhood, The Outdoor Type, titled after Toni Morrison’s rendition of being ‘outdoors’ in The Bluest Eye, considers the intersection of marriage, memory, and comfort. The novel, set in Chicago, simultaneously characterizes Chicago and black experiences by fictionalizing actual south side of Chicago events and community members.
Dynamical Mass Measurement of the Young Spectroscopic Binary V343 Normae AaAb Resolved With the Gemini Planet Imager
Creators: name: Nielsen, Eric L.
name: De Rosa, Robert J.
name: Wang, Jason
name: Rameau, Julien
name: Song, Inseok
name: Graham, James R.
name: Macintosh, Bruce
name: Ammons, Mark
name: Bailey, Vanessa P.
name: Barman, Travis S.
name: Bulger, Joanna
name: Chilcote, Jeffrey K.
name: Cotten, Tara
name: Doyon, Rene
name: Duchene, Gaspard
name: Fitzgerald, Michael P.
name: Follette, Katherine B.
name: Greenbaum, Alexandra Z.
name: Hibon, Pascale
name: Hung, Li-Wei
name: Ingraham, Patrick
name: Kalas, Paul
name: Konopacky, Quinn M.
name: Larkin, James E.
name: Maire, Jerome
name: Marchis, Franck
name: Marley, Mark S.
name: Marois, Christian
name: Metchev, Stanimir
name: Millar-Blanchaer, Maxwell A.
name: Oppenheimer, Rebecca
name: Palmer, David W.
name: Patience, Jenny
name: Perrin, Marshall D.
name: Poyneer, Lisa A.
name: Pueyo, Laurent
name: Rajan, Abhijith
name: Rantakyro, Fredrik T.
name: Savransky, Dmitry
name: Schneider, Adam C.
name: Sivaramakrishnan, Anand
name: Soummer, Remi
name: Thomas, Sandrine
name: Wallace, J. Kent
name: Ward-Duong, Kimberly
name: Wiktorowicz, Sloane J.
name: Wolff, Schuyler G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present new spatially resolved astrometry and photometry from the Gemini Planet Imager of the inner binary of the young multiple star system V343 Normae, which is a member of the beta Pictoris moving group. V343 Normae comprises a K0 and mid-M star in a ~4.5 year orbit (AaAb) and a wide 10" M5 companion (B). By combining these data with archival astrometry and radial velocities we fit the orbit and measure individual masses for both components of M_Aa = 1.10 +/- 0.10 M_sun and M_Ab = 0.290 +/- 0.018 M_sun. Comparing to theoretical isochrones, we find good agreement for the measured masses and JHK band magnitudes of the two components consistent with the age of the beta Pic moving group. We derive a model-dependent age for the beta Pic moving group of 26 +/- 3 Myr by combining our results for V343 Normae with literature measurements for GJ 3305, which is another group member with resolved binary components and dynamical masses.
description: 12 pages, 7 figures. Accepted to AJ