cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Anomalous Hall effect in insulating Ga1-xMnxAs
Creators: name: Yuldashev, Sh. U.
name: Jeon, H. C.
name: Im, H. S.
name: Kang, T. W.
name: Lee, S. H.
name: Furdyna, J. K.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We have investigated the effect of doping by Te on the anomalous Hall effect in Ga1-xMnxAs (x = 0.085). For this relatively high value of x the temperature dependence of resistivity shows an insulating behavior. It is well known that in Ga1-xMnxAs the Mn ions naturally act as acceptors. Additional doping by Te donors decreases the Curie temperature and increases the anomalous Hall resistivity. With increasing Te concentration the long-range ferromagnetic order in Ga1-xMnxAs eventually disappears, and paramagnetic-to-spin glass transition is observed instead. The critical concentration of holes required for establishing ferromagnetic order in Ga1-xMnxAs (x = 0.085) has been estimated by using the magnetic polaron percolation theory proposed by Kaminski and Das Sarma [Phys.Rev.Lett. 88, 247202 (2002)].
description: 15 pages, 5 figures. Phys. Rev. B (to be published)
Uimastite tarvitamine Eesti noorte ja täisealiste seas. AAA-uuringu esmased tulemused
Creators: name: Haring, Liina
name: Leedo, Anni
name: Kisand, Helena
name: Voormansik, Liina
name: Viimsalu, Annika
name: Karis, Karina
name: Kangro, Raul
name: Vasar, Eero
Publisher: name: Eesti Arst
Year: 2021

description: Taust ja eesmärk. Alkoholi, tubakatoodete ja illegaalsete uimastite tarvitamine on üha suurenev üleilmne probleem. Artikli eesmärk on anda ülevaade Eesti noorte inimeste uimastite kasutamise levimusuuringu „Ained ja arenevad ajud“ (AAA-uuring) esmastest tulemustest. Metoodika. Uuringus osales 4922 isikut, kelle keskmine vanus oli 21,4 ± 6,8 aastat (vahemik 16–45 a). Elu jooksul ja viimase 3 kuu jooksul tarvitatud uimastite määr tuvastati mõõtevahendi ASSIST (Alcohol, Smoking and Substance use Involvement Screening Test) abil. Andmete kogumiseks kasutati veebiplatvormi REDCap. Tulemused. Uuringus osalejatest oli elu jooksul vähemalt korra tarvitanud alkoholi 86,1% ja tubakatooteid 60,5%. Kanep oli kõige sagedamini (43,0%) proovitud illegaalne uimasti. Amfetamiinitüüpi stimulante oli vähemalt korra elus proovinud 15,2%, hallutsinogeene 12,5%, inhalante 8,1%, kokaiini 7,7% ja opioide 3,7% küsimustikule vastanutest. Kolme viimase kuu jooksul oli 77,6% uuringus osalenutest pruukinud alkoholi, sageduselt järgnesid tubaka (43,0%) ja kanepi (24,5%) tarvitamine. Esitatud on ka andmed erinevaid uimasteid elu jooksul vähemalt korra tarvitanud isikute jaotuse kohta maakonniti ning piirkonniti. Arutelu. Uuring kinnitab varasemaid tulemusi, et noorte hulgas on uimastite tarvitamise levimus suur. Nii legaalsete kui ka illegaalsete uimastite tarvitamine on sagedasem kui arvatud, eriti noorte hulgas. Seetõttu on soovitatav tõhustada alkoholi, tubaka ja illegaalsete ainete tarvitamise vähendamisele suunatud ennetuse ja sekkumisega seotud tegevusi Eesti noorte hulgas.
description: Eesti Arst, 2021: Jaanuar
Bang-Bang refocusing of a qubit exposed to telegraph noise
Creators: name: Gutmann, H.
name: Wilhelm, F. K.
name: Kaminsky, W. M.
name: Lloyd, S.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We investigate the decoherence effect of telegraph noise on a single qubit, usually provoked by bistable fluctuators. To diminish the dephasing and relaxation impact an effective refocusing scheme (so-called Bang-Bang pulses) is proposed. Detailed numerical as well as analytical random walk analysis allows in particular to evaluate the applicability of non-perfect Bang-Bang pulses.
Optical-state truncation and teleportation of qudits by conditional eight-port interferometry
Creators: name: Miranowicz, Adam
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum scissors device of Pegg et al. (1998 Phys. Rev. Lett. 81, 1604) enables truncation of the Fock-state expansion of an input optical field to qubit and qutrit (three-dimensional) states only. Here, a generalized scissors device is proposed using an eight-port optical interferometer. Upon post-selection based on photon counting results, the interferometer implements generation and teleportation of qudit (d-dimensional) states by truncation of an input field at the (d-1)th term of its Fock-state expansion up to d=6. Examples of selective truncations, which can be interpreted as a Fock-state filtering and hole burning in the Fock space of an input optical field, are discussed. Deterioration of the truncation due to imperfect photon counting is discussed including inefficiency, dark counts and realistic photon-number resolutions of photodetectors.
description: 10 pages, 3 figures
Witness-based Approach for Scaling Distributed Ledgers to Massive IoT Scenarios
Creators: name: Nguyen, Lam D.
name: Leyva-Mayorga, Israel
name: Popovski, Petar
Publisher: name: arXiv
Year: 2020
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Distributed Ledger Technologies (DLTs) are playing a major role in building security and trust in Internet of Things (IoT) systems. However, IoT deployments with a large number of devices, such as in environment monitoring applications, generate and send massive amounts of data. This would generate vast number of transactions that must be processed within the distributed ledger. In this work, we first demonstrate that the Proof of Work (PoW) blockchain fails to scale in a sizable IoT connectivity infrastructure. To solve this problem, we present a lightweight distributed ledger scheme to integrate PoW blockchain into IoT. In our scheme, we classify transactions into two types: 1) global transactions, which must be processed by global blockchain nodes and 2) local transactions, which can be processed locally by entities called witnesses. Performance evaluation demonstrates that our proposed scheme improves the scalability of integrated blockchain and IoT monitoring systems by processing a fraction of the transactions, inversely proportional to the number of witnesses, locally. Hence, reducing the number of global transactions.
description: 6 pages, 7 figures, conference paper
Dynamic roughening of the magnetic flux landscape in YBa$_2$Cu$_3$O$_{7-x}$
Creators: name: Aegerter, C. M.
name: Welling, M. S.
name: Wijngaarden, R. J.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study the magnetic flux landscape in YBa$_2$Cu$_3$O$_{7-x}$ thin films as a two dimensional rough surface. The vortex density in the superconductor forms a self-affine structure in both space and time. This is characterized by a roughness exponent $α= 0.76(3)$ and a growth exponent $β= 0.57(6)$. This is due to the structure and distribution of flux avalanches in the self-organized critical state, which is formed in the superconductor. We also discuss our results in the context of other roughening systems in the presence of quenched disorder.
description: 13 pages, 7 figures, accepted for publication in Physica A
Fano resonances in optical spectra of semiconductor quantum wells driven by an oscillating field
Creators: name: Kibis, O. V.
name: Kolodny, S. A.
name: Iorsh, I. V.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Optical spectra of semiconductor quantum wells driven by an off-resonant oscillating field are studied theoretically. Due to the dynamical stabilization effect, the field induces the quasi-stationary electron states confined at repulsive scatterers and immersed into the continuum of states of conduction electrons. As a result, the Fano resonances in the spectra of interband optical transitions appear near the energies of the quasi-stationary states.
description: Published version
Diagnosis and treatment of a choledochal cyst during pregnancy. A case Report
Creators: name: Jonathan Abraham Escamilla Escobar M.D.
name: Maria Fernanda Figueroa Romo M.D.
name: Paul Vicente Molinar Orozco M.D.
name: Alfredo Gallardo Carreon M.D.
name: Jose Yair Senakarib Barbosa Santana M.D.
name: Edgardo Camarena M.D.
Publisher: name: Zenodo
Year: 2024

description: Background:

Choledochal cysts are a rare pathology of the biliary tree, more commonly found in females and predominantly presented in childhood. Their occurrence in adulthood, particularly during pregnancy, is rare, often presenting with nonspecific signs and symptoms, which can lead to a delay in diagnosis.

We present the case of a 29-year-old female patient who began experiencing symptoms at 8 weeks of gestation. She was initially misdiagnosed with acute lithiasic cholecystitis. During intervention at 12 weeks of gestation, a Type IVa choledochal cyst was found. Initial management involved decompressing the biliary tract via a T-tube due to the complexity of the case. Subsequently, after two episodes of cholangitis, surgical management was decided before the resolution of the pregnancy, through resection of the choledochal cyst and Roux-en-Y hepaticojejunostomy. Currently, her clinical status is favorable; she completed her pregnancy at term via scheduled cesarean section without apparent maternal-fetal complications.

 

Keywords: Choledochal cysts.
Modelling human-to-human transmission of monkeypox: Supporting Information
Creators: name: Grant, Rebecca
name: Liem-Binh Luong Nguyen
name: Breban, Romulus
Publisher: name: figshare
Year: 2020
Subjects: subject: 111706 Epidemiology
subject: FOS: Health sciences
subject: 110309 Infectious Diseases

description: This material brings technical information in support of the publication:
R Grant, L-B Nguyen, and R Breban. Modelling human-to-human transmission of monkeypox. Bulletin of the World Health Organization, 2020.
"Chileans' anger at inequality boils over" : The "Estallido Social" and the role of relative deprivation feelings and perceptions of economic inequality in social protests
Creators: name: Lattz, Miguel
Publisher: name: The Australian National University
Year: 2024

description: In October 2019, the "Estallido Social" demonstrations began in Chile. The protests originated from a growing critique of the government economic development model and the levels of inequality in the country. The social demands were varied and included several areas of Chilean society, from writing a new constitution to improving gender disparities. As a result, these Chilean demands for a more equalitarian country led to a 2020 referendum and the later creation of the Constitutional Assembly. Using International Social Survey Programme data from 2009 and 2019, and a theoretical framework based on Social Justice and Relative Deprivation Theory, I argue that the protests that started in 2019 were a consequence of a process that began years ago. Initial analysis pointed out that the 2019 demonstrations stemmed from earlier public discontent based on a perception that inequality was increasing, generating a more socially segregated society. Thus, the "Estallido Social" is based on the perception of an unequal country and a lack of trust in the institutions that should prevent it. However, my research also shows that the "Estallido" has a counter-intuitive origin, namely from a criticism of the perceived levels of economic inequality at a time when Chileans perceived less inequality than in the past. Thus, why did the "Estallido" begin in 2019 and not before when perceived inequality was greater? The research concludes that at the base of the demonstrations was an imbalance between what Chileans perceived and what they tolerated as a fair level of economic inequality. Perceptions of actual and just economic inequality relate to each other in order to explain deprivation feelings. Relative deprivation feelings regarding perceived economic inequality have increased in the last years among Chileans, and it is another variable that must be included to explicate the massiveness of the Chileans' protests.
Brane world generation by matter and gravity
Creators: name: Andrianov, A. A.
name: Andrianov, V. A.
name: Giacconi, P.
name: Soldati, R.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a non-compact (4 + 1) dimensional model with a local strong four-fermion interaction supplementing it with gravity. In the strong coupling regime it reveals the spontaneous translational symmetry breaking which eventually leads to the formation of domain walls, or thick 3-branes, embedded in the AdS-5 manifold. To describe this phenomenon we construct the appropriate low-energy effective Action and find kink-like vacuum solutions in the quasi-flat Riemannian metric. We discuss the generation of ultra-low-energy (3 + 1) dimensional physics and we establish the relation among the bulk five dimensional gravitational constant, the brane Newton's constants and the curvature of AdS-5 space-time. The plausible relation between the compositeness scale of the scalar matter and the symmetry breaking scale is shown to support the essential decoupling of branons, the scalar fluctuations of the brane, from the Standard Model matter, supporting their possible role in the dark matter saturation. The induced cosmological constant on the brane does vanish due to exact cancellation of matter and gravity contributions.
description: 35 pages, JHEP3 style, refs.added
Vertical coordination in high-value commodities: Implications for Smallholders
Creators: name: Birthal, Pratap Singh
name: Joshi, P.K.
name: Gulati, Ashok
name: Birthal, Pratap Singh
name: Joshi, P.K.
name: Gulati, Ashok
Publisher: name: Unknown
Year: 2005
Subjects: subject: Agribusiness
subject: High value commodities
subject: Urbanization
subject: High value agriculture
subject: Scaling up

description: Rising per capita income, urbanization and globalization are changing the consumption basket in the developing countries towards high-value commodities (like fruits & vegetables, milk, meat, poultry, fish, etc.). This paper explores how smallholders can benefit from the emerging opportunities from a silent demand-driven changes in high-value agriculture in India. The study examines the institutional mechanisms adopted by different firms to integrate small producers of milk, broilers and vegetables in supply chain and their effects on producers’ transaction costs and farm profitability. The study finds that the innovative institutional arrangements in the form of contract farming have considerably reduced transaction costs and improved market efficiency to benefit the smallholders. The study does not find any bias against smallholders in contract farming. Also, the study does not find that the relevant firms have exploited their monopsonistic position by paying lower prices to farmers. On the contrary, contract producers were found enjoying benefits of assured procurement of their produce and higher prices. The study lists policy hurdles in scaling up the innovative models of vertical coordination in high-value food commodities.
3D Bird Reconstruction: a Dataset, Model, and Shape Recovery from a Single View
Creators: name: Badger, Marc
name: Wang, Yufu
name: Modh, Adarsh
name: Perkes, Ammon
name: Kolotouros, Nikos
name: Pfrommer, Bernd G.
name: Schmidt, Marc F.
name: Daniilidis, Kostas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences
subject: I.4.8

description: Automated capture of animal pose is transforming how we study neuroscience and social behavior. Movements carry important social cues, but current methods are not able to robustly estimate pose and shape of animals, particularly for social animals such as birds, which are often occluded by each other and objects in the environment. To address this problem, we first introduce a model and multi-view optimization approach, which we use to capture the unique shape and pose space displayed by live birds. We then introduce a pipeline and experiments for keypoint, mask, pose, and shape regression that recovers accurate avian postures from single views. Finally, we provide extensive multi-view keypoint and mask annotations collected from a group of 15 social birds housed together in an outdoor aviary. The project website with videos, results, code, mesh model, and the Penn Aviary Dataset can be found at https://marcbadger.github.io/avian-mesh.
description: In ECCV 2020
Fault-Tolerant Quantum Dynamical Decoupling
Creators: name: Khodjasteh, K.
name: Lidar, D. A.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Dynamical decoupling pulse sequences have been used to extend coherence times in quantum systems ever since the discovery of the spin-echo effect. Here we introduce a method of recursively concatenated dynamical decoupling pulses, designed to overcome both decoherence and operational errors. This is important for coherent control of quantum systems such as quantum computers. For bounded-strength, non-Markovian environments, such as for the spin-bath that arises in electron- and nuclear-spin based solid-state quantum computer proposals, we show that it is strictly advantageous to use concatenated, as opposed to standard periodic dynamical decoupling pulse sequences. Namely, the concatenated scheme is both fault-tolerant and super-polynomially more efficient, at equal cost. We derive a condition on the pulse noise level below which concatenated is guaranteed to reduce decoherence.
description: 5 pages, 4 color eps figures. v3: Minor changes. To appear in Phys. Rev. Lett
Epigeobiont Carabidae and Pselaphinae beetles (Coleoptera) from high altitude coniferous forests in Bulgaria. Preliminary results.
Creators: name: Kostova, Rumyana
name: Bekchiev, Rostislav
Publisher: name: Zenodo
Year: 2021
Subjects: Ground beetles, Pselaphines, biodiversity, endemism, coniferous communities

description: The presented preliminary study summarizes the available information and adds new data about the Carabidae and Pselaphinae (Insecta: Coleoptera) species composition in high altitude coniferous forests. The study of these beetle groups in endemic and relict Pinus peuce and Pinus heldreichii communities in Bulgaria was made for the first time. The results from the first period of the field expeditions in the forests with Pinus peuce and Pinus heldreichii communities, as well the literature data about both beetle groups in high altitude Picea abies communities in Bulgaria are shown. The species richness and endemism of Carabidae and Pselaphinae is commented.
Physics of Transport and Traffic Phenomena in Biology: from molecular motors and cells to organisms
Creators: name: Chowdhury, Debashish
name: Schadschneider, Andreas
name: Nishinari, Katsuhiro
Publisher: name: arXiv
Year: 2005
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Traffic-like collective movements are observed at almost all levels of biological systems. Molecular motor proteins like, for example, kinesin and dynein, which are the vehicles of almost all intra-cellular transport in eukayotic cells, sometimes encounter traffic jam that manifests as a disease of the organism. Similarly, traffic jam of collagenase MMP-1, which moves on the collagen fibrils of the extracellular matrix of vertebrates, has also been observed in recent experiments. Traffic-like movements of social insects like ants and termites on trails are, perhaps, more familiar in our everyday life. Experimental, theoretical and computational investigations in the last few years have led to a deeper understanding of the generic or common physical principles involved in these phenomena. In particular, some of the methods of non-equilibrium statistical mechanics, pioneered almost a hundred years ago by Einstein, Langevin and others, turned out to be powerful theoretical tools for quantitaive analysis of models of these traffic-like collective phenomena as these systems are intrinsically far from equilibrium. In this review we critically examine the current status of our understanding, expose the limitations of the existing methods, mention open challenging questions and speculate on the possible future directions of research in this interdisciplinary area where physics meets not only chemistry and biology but also (nano-)technology.
description: 33 page Review article, REVTEX text, 29 EPS and PS figures
On characteristic initial data for a star orbiting a black hole
Creators: name: Bishop, Nigel T.
name: Gomez, Roberto
name: Lehner, Luis
name: Maharaj, Manoj
name: Winicour, Jeffrey
Publisher: name: arXiv
Year: 2004
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We take further steps in the development of the characteristic approach to enable handling the physical problem of a compact self-gravitating object, such as a neutron star, in close orbit around a black hole. We examine different options for setting the initial data for this problem and, in order to shed light on their physical relevance, we carry out short time evolution of this data. To this end we express the matter part of the characteristic gravity code so that the hydrodynamics are in conservation form. The resulting gravity plus matter relativity code provides a starting point for more refined future efforts at longer term evolution. In the present work we find that, independently of the details of the initial gravitational data, the system quickly flushes out spurious gravitational radiation and relaxes to a quasi-equilibrium state with an approximate helical symmetry corresponding to the circular orbit of the star.
description: 20 pages, 10 figures
Adaptive Matrix Completion
Creators: name: Ramazanli, Ilqar
Publisher: name: Carnegie Mellon University
Year: 2020
Subjects: subject: 80201 Analysis of Algorithms and Complexity
subject: FOS: Computer and information sciences

description: In this thesis we study the problem of exact completion for 𝑚 × 𝑛 sized matrix of rank 𝑟 and the problem of low-rank estimation with the adaptive sampling method. We introduce a relation of the exact completion problem with the sparsest vector of column and row spaces. Using this relation, wepropose matrix completion algorithms that exactly recovers the target matrix. These algorithms are superior to previous works in two important ways. First, our algorithms exactly recovers 𝜇0-coherent column space matrices byprobability at least 1 − 𝜖 using much smaller observations complexity than - 𝒪(𝜇0𝑟𝑛log𝑟 𝜖 )—the state of art. Specifically, many of the previous adaptive sampling methods require to observe the entire matrix when the column space is highly coherent. However, we show that our method is still able to recover this type of matrices by observing a small fraction of entries under many scenarios. Second, we propose an exact completion algorithm, whichrequires minimal pre-information as either row or column space is not being highly coherent. We provide an extension of these algorithms that is robust to sparse random noise. Besides, we propose an additional low-rank estimationalgorithm that is robust to any small noise by adaptively studying the shape of column space. At the end of the thesis, we provide experimental results that illustrate the strength of the algorithms proposed here. This thesis have been written mainly based on the paper [12].
A certificação orgânica como fator estratégico na governança das transações no mercado de alimentos
Creators: name: Cesar, Aldara Da Silva
name: Batalha, Mario Otavio
name: Pimenta, Marcio Lopes
name: Cesar, Aldara Da Silva
name: Batalha, Mario Otavio
name: Pimenta, Marcio Lopes
Publisher: name: Unknown
Year: 2008
Subjects: subject: Agribusiness
subject: Agricultural Finance
subject: Industrial Organization
subject: certification
subject: transaction costs
subject: organic products
subject: organic production

description: Food consumers are, in general, concerned with acquiring healthy food which does not pose risks to their health. These preferences are directly related to the way the economic agents organize themselves inside the food sector. In this context, the organic products’ share in the food market is rising considerably, mainly because they consist not only of a healthier product, but also because they contribute positively to the environment. Nevertheless, these characteristics are not immediately observed by the consumers, which makes the certification process an essential mechanism not in the transaction process but also in gaining the confidence of several markets. This article lists some advantages and disadvantages of the certification process raised in the literature, pointing out the reorganization that this process promotes inside the described productive chain. It can be affirmed that certification represents an impediment, as the conversion costs from the conventional system to the organic system and the entire certification process make the entrance into this sector difficult, especially for small-scale producers. However, some limitations have been compensated by the enhanced position of the differentiated product in the market. In most countries, including Brazil, consumers are willing to pay a price-premium for this kind of product, which has been the main reason behind the segment’s sustainability.
Quantifying Community Characteristics of Maternal Mortality Using Social Media
Creators: name: Abebe, Rediet
name: Giorgi, Salvatore
name: Tedijanto, Anna
name: Buffone, Anneke
name: Schwartz, H. Andrew
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computation and Language (cs.CL)
subject: Computers and Society (cs.CY)
subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: While most mortality rates have decreased in the US, maternal mortality has increased and is among the highest of any OECD nation. Extensive public health research is ongoing to better understand the characteristics of communities with relatively high or low rates. In this work, we explore the role that social media language can play in providing insights into such community characteristics. Analyzing pregnancy-related tweets generated in US counties, we reveal a diverse set of latent topics including Morning Sickness, Celebrity Pregnancies, and Abortion Rights. We find that rates of mentioning these topics on Twitter predicts maternal mortality rates with higher accuracy than standard socioeconomic and risk variables such as income, race, and access to health-care, holding even after reducing the analysis to six topics chosen for their interpretability and connections to known risk factors. We then investigate psychological dimensions of community language, finding the use of less trustful, more stressed, and more negative affective language is significantly associated with higher mortality rates, while trust and negative affect also explain a significant portion of racial disparities in maternal mortality. We discuss the potential for these insights to inform actionable health interventions at the community-level.
description: In Proceedings of The Web Conference 2020(WWW '20)
Exploring drought resilience in Australian tree species.
Creators: name: Bryant, Cal
Publisher: name: The Australian National University
Year: 2024

description: Global climate change is challenging many forested ecosystems with elevated temperatures and increasingly severe and frequent drought, heat waves, and outbreaks of biotic agents. Escalating forest dieback occurrences in response to changing abiotic and biotic pressures have significant implications for ecosystem structure, biodiversity, and terrestrial fluxes of carbon and water. This thesis comprises a compilation of four independent studies exploring the contribution of hydraulic and water relations traits to drought resilience and vulnerability in Australian tree species. Chapter 1 focuses on novel pathways of top-down tree rehydration from atmospheric water sources in two mangrove species of the Sonneratia genus, and variability in the conductance of these pathways due to seasonality and dehydration. Chapter 2 explores the contribution of dry season acclimation of traits influencing water use and water storage to the maintenance of gas exchange and mitigation of loss of hydraulic function in the mangrove Sonneratia alba. Chapter 3 explores variation in drought and structural traits among two snow-gum subspecies (Eucalyptus pauciflora subsp. pauciflora and Eucalyptus pauciflora subsp. niphophila) and trait associations with elevation-dependent spatial patterns of wood borer-mediated dieback in Australia's subalpine woodlands. Finally, Chapter 4 explores the cross-tolerant effects of salinity gradients and leaf dehydration on photosynthetic (PSII) heat tolerance in twelve mangrove species distributed along a salinity gradient. These chapters provide evidence of spatial and seasonal variation in trait expression and their interactions with plant-water balance and drought resilience within and between species. For many unmanaged forests, greater resolution of these complex biotic-environmental interactions will be essential for the reliable modelling and effective management of forest resilience under future climates.
The Summarization of hierarchical data with exceptions
Creators: name: Bu, Shaofeng
Publisher: name: University of British Columbia
Year: 2009

description: In many applications of OLAP or data warehouse, users need to query data of interest, such as a set of data that satisfies specific properties. A normal answer to such query just enumerates all the interesting cells. This is the most accurate but not the most informative method. Summarizations need to be done in order to return more concise descriptions of these interesting cells to the users. MDL approach has been applied on the hierarchical data to get concise descriptions. However in many cases the descriptions are not concise enough to the users. Another method, GMDL, can generate much shorter descriptions, but the GMDL descriptions are not truly pure. The motivation of our research is to overcome the disadvantages in the above methods. In this thesis, we bring up a methodology that focuses on generating the summarization with exceptions of the hierarchical data. We extend the MDL approach to include some exceptions in the description. The exceptios are some uninteresting cells. The result shows that the description with exceptions is pure, which means that the description only covers "interesting cells". We call this new approach MDLE, i.e. MDL with exceptions. Our new approach aims to find the shortest description with exceptions to cover all "interesting cells". Firstly, we study two simple cases that can be solved in polynomial time and we give the algorithms. Secondly, we prove that MDL with exceptions is an NP-Hard problem in general cases and we propose three heuristics. Finally, we show some experiments that we have done to compare MDLE with MDL and GMDL . The experiment results show that MDLE generates more concise descriptions than MDL and meantime MDLE gets shorter descriptions than GMDL when the white-ratio is low or there are some red cells.
Optical estimation of unitary Gaussian processes without phase reference using Fock states
Creators: name: Oh, Changhun
name: Park, Kimin
name: Filip, Radim
name: Jeong, Hyunseok
name: Marek, Petr
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Since a general Gaussian process is phase-sensitive, a stable phase reference is required to take advantage of this feature. When the reference is missing, either due to the volatile nature of the measured sample or the measurement's technical limitations, the resulting process appears as random in phase. Under this condition, we consider two single-mode Gaussian processes, displacement and squeezing. We show that these two can be efficiently estimated using photon number states and photon number resolving detectors. For separate estimation of displacement and squeezing, the practical estimation errors for hundreds of probes' ensembles can saturate the Cramér-Rao bound even for arbitrary small values of the estimated parameters and under realistic losses. The estimation of displacement with Fock states always outperforms estimation using Gaussian states with equivalent energy and optimal measurement. For estimation of squeezing, Fock states outperform Gaussian methods, but only when their energy is large enough. Finally, we show that Fock states can also be used to estimate the displacement and the squeezing simultaneously.
description: 16 pages, 8 figures
Photothermal effects, Optomechanics and Optical Levitation
Creators: name: Gu, Chenyue
Publisher: name: The Australian National University
Year: 2024

description: The invention of lasers enabled strong and controllable interactions between light and small objects. Radiation pressure provides a unique tool for optomechanical control and manipulation of the quantum state of a mechanical oscillator. The high power density and photon flux of laser radiation lead to extremely high heating rates at surfaces, which induce measurement noise and is hence considered harmful in sensing systems. Optomechanical interaction can also be mediated by photothermal effects which, although frequently overlooked, may compete with radiation pressure interaction. A complete understanding of how these phenomena affect the coherent exchange of information between optical and mechanical degrees of freedom is yet undeveloped, particularly in mesoscale high-power systems where photothermal effects can fully dominate the interaction. Here we investigate the photothermal effects in a unique optomechanical system: a cavity-enhanced setup for macroscopic optical levitation, where a free-standing mirror acts as the optomechanical oscillator. In this system, we observe the photothermally induced instability when the optical cavity is driven by a high-power laser. We show that the possible thermally induced parametric gain can be reduced and even cancelled out with a modification to the photothermal properties of an optomechanical cavity experimentally, by inserting windows into the cavity. Theocratically, we report an effective theoretical model to predict and successfully reconstruct the dynamics of this system. By decomposing the photothermal interaction into two opposing light-induced effects, photothermal expansion and thermo-optic effects, we reconstruct a heuristic model based on the mutual interaction between the intracavity field and four position degrees of freedom, offering refined predictions that provide a high agreement with the experimental result. We also provided a detailed discussion on the effectiveness of different models, and have concluded that two photothermal effects are necessary in the model for simulating the dynamics of the optomechanical levitation system studied. Overall, the experimental and theoretical investigations presented in this thesis set essential groundwork for the characterization and stabilisation of existing systems and a deeper understanding of photothermal effects in optomechanical systems. The methods that used in the investigation and cancellation of photothermal effects in this system can be easily applied to other similar optomechanical system where high-intensity laser is used or high precision of the measurement is desired. This work facilitates the development of new and more precise optomechanical systems for integrated photonics and sensing, and paves the way to fundamental studies in quantum mechanics.
Quantum computing and polynomial equations over the finite field Z_2
Creators: name: Dawson, Christopher M.
name: Haselgrove, Henry L.
name: Hines, Andrew P.
name: Mortimer, Duncan
name: Nielsen, Michael A.
name: Osborne, Tobias J.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: What is the computational power of a quantum computer? We show that determining the output of a quantum computation is equivalent to counting the number of solutions to an easily computed set of polynomials defined over the finite field Z_2. This connection allows simple proofs to be given for two known relationships between quantum and classical complexity classes.
description: 7 pages, 3 figures
Fluctuating Relativistic hydrodynamics from Crooks theorem
Creators: name: Torrieri, Giorgio
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We use the Crooks fluctuation theorem together with Zubarev hydrodynamics to develop a bottom-up theory of hydrodynamic fluctuations. We also use thermodynamic uncertainity relations to estimate bottom-up limits to dissipative transport coefficients.
description: Small typos fixed in accordance to proofs
A novel series solution to the renormalization group equation in QCD
Creators: name: Magradze, B. A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Recently, the QCD renormalization group (RG) equation at higher orders in MS-like renormalization schemes has been solved for the running coupling as a series expansion in powers of the exact 2-loop order coupling. In this work, we prove that the power series converges to all orders in perturbation theory. Solving the RG equation at higher orders, we determine the running coupling as an implicit function of the 2-loop order running coupling. Then we analyze the singularity structure of the higher order coupling in the complex 2-loop coupling plane. This enables us to calculate the radii of convergence of the series solutions at the 3- and 4-loop orders as a function of the number of quark flavours $n_{\rm f}$. In parallel, we discuss in some detail the singularity structure of the ${\bar{\rm MS}}$ coupling at the 3- and 4-loops in the complex momentum squared plane for $ 0\leq n_{\rm f} \leq 16 $. The correspondence between the singularity structure of the running coupling in the complex momentum squared plane and the convergence radius of the series solution is established. For sufficiently large $n_{\rm f}$ values, we find that the series converges for all values of the momentum squared variable $Q^2=-q^2>0$. For lower values of $n_{\rm f}$, in the ${\bar{\rm MS}}$ scheme, we determine the minimal value of the momentum squared $Q_{\rm min}^2$ above which the series converges. We study properties of the non-power series corresponding to the presented power series solution in the QCD Analytic Perturbation Theory approach of Shirkov and Solovtsov. The Euclidean and Minkowskian versions of the non-power series are found to be uniformly convergent over whole ranges of the corresponding momentum squared variables.
description: 29 pages,LateX file, uses IOP LateX class file, 2 figures, 13 Tables. Formulas (4)-(7) and Table 1 were relegated to Appendix 1, some notations changed, 2 footnotes added. Clarifying discussion added at the end of Sect. 3, more references and acknowledgments added. Accepted for publication in Few-Body Systems
COMÉRCIO JUSTO INTERNACIONAL: O CASO DO SUCO DE LARANJA ENTRE O BRASIL E A FRANÇA
Creators: name: Machado, Melise Dantas
name: Paulillo, Luiz Fernando
name: Lambert, Annie
name: Machado, Melise Dantas
name: Paulillo, Luiz Fernando
name: Lambert, Annie
Publisher: name: Unknown
Year: 2008
Subjects: subject: Agribusiness
subject: Agricultural Finance
subject: Industrial Organization
subject: transaction costs
subject: governance structures
subject: networks
subject: fair trade
subject: orange juice.

description: This paper is a preliminary analysis of the governance structure of the faire trade of orange juice between Brazil and France. Fair trade is an organizational field composed of complex organizational networks that maintain relations of mutual dependence and share the same values system. As fair trade is a subject that has received relatively little study and presents many particularities, an exploratory study was considered appropriate. Primary and secondary data were collected. In the case of the trade of orange juice between Brazil and France, two commercial networks were identified. The integrated network is constituted by professionals who specialize in fair trade, while the certified network includes more conventional commercial organizations, such as supermarkets. However, although they adopt different functioning mechanisms, in the case of orange juice the importers in the integrated network have integrated themselves into the certified network. In this way, they meet the requirements of the certified network and follow its rules for importing Brazilian orange juice. After analyzing the intrinsic characteristics of the product, the asset specificity, the frequency and the uncertainty of the transactions, the governance structure observed was the hybrid arrangement, in which long-term contracts are used to coordinate relations.
Learnability and Robustness of Shallow Neural Networks Learned With a Performance-Driven BP and a Variant PSO For Edge Decision-Making
Creators: name: He, Hongmei
name: Chen, Mengyuan
name: Xu, Gang
name: Zhu, Zhilong
name: Zhu, Zhenhuan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: Machine Learning (cs.LG)
subject: Performance (cs.PF)
subject: FOS: Computer and information sciences
subject: I.2; I.2.6
subject: 68T07, 68T05

description: In many cases, the computing resources are limited without the benefit from GPU, especially in the edge devices of IoT enabled systems. It may not be easy to implement complex AI models in edge devices. The Universal Approximation Theorem states that a shallow neural network (SNN) can represent any nonlinear function. However, how fat is an SNN enough to solve a nonlinear decision-making problem in edge devices? In this paper, we focus on the learnability and robustness of SNNs, obtained by a greedy tight force heuristic algorithm (performance driven BP) and a loose force meta-heuristic algorithm (a variant of PSO). Two groups of experiments are conducted to examine the learnability and the robustness of SNNs with Sigmoid activation, learned/optimised by KPI-PDBPs and KPI-VPSOs, where, KPIs (key performance indicators: error (ERR), accuracy (ACC) and $F_1$ score) are the objectives, driving the searching process. An incremental approach is applied to examine the impact of hidden neuron numbers on the performance of SNNs, learned/optimised by KPI-PDBPs and KPI-VPSOs. From the engineering prospective, all sensors are well justified for a specific task. Hence, all sensor readings should be strongly correlated to the target. Therefore, the structure of an SNN should depend on the dimensions of a problem space. The experimental results show that the number of hidden neurons up to the dimension number of a problem space is enough; the learnability of SNNs, produced by KPI-PDBP, is better than that of SNNs, optimized by KPI-VPSO, regarding the performance and learning time on the training data sets; the robustness of SNNs learned by KPI-PDBPs and KPI-VPSOs depends on the data sets; and comparing with other classic machine learning models, ACC-PDBPs win for almost all tested data sets.
description: 36 pages, 21 figues for corresponding eps files. Neural Comput & Applic (2021)
Advancing the Field of Soft Scorpionates Ligated to Carbyne, Aminocarbyne and Tricarbido Complexes
Creators: name: Welsh, Steven
Publisher: name: The Australian National University
Year: 2024

description: Although the first Scorpionate ligand, Tp, was prepared some 56 years prior to the writing of this thesis, Scorpionates continue to be widely used throughout multiple areas of chemistry. In particular, Scorpionates have found broad utility in organometallic and coordination chemistry, due to the ease at which their steric and electronic impacts may be tailored to suit various metal-containing systems. In this regard, they have become a cornerstone within the field, and remain a common feature in new literature publications. Taking all pre-existing literature into account, pyrazole-based Scorpionate ligands, containing hard-donor atoms, feature in the majority of these publications. However, the work detailed in this thesis aims to further bolster the relatively underdeveloped field of Scorpionate ligands featuring soft donor groups, and their incorporation into organometallic systems. Examples of such soft Scorpionate ligands include Bm, Tm, Hbt, and Htt, which coordinate to metal centres via their exocyclic sulfur atoms, situated on their heterocyclic rings. The sections within this thesis describe the methods through which these soft Scorpionate ligands have been successfully incorporated into: tungsten and molybdenum propargylidyne complexes; tungsten and molybdenum metallacarbyne complexes containing polycyclic aromatic hydrocarbons; and, tungsten and molybdenum aminocarbyne complexes. Wherever possible, full spectral characterisation has been carried out and discussed briefly throughout these chapters. However, full details may be found in the Experimental Section, and in the accompanying Supplementary Information.
Bidirectional importance sampling for illumination from environment maps
Creators: name: Burke, David
Publisher: name: University of British Columbia
Year: 2009

description: Image-based representations for illumination are able to capture complex real-world lighting that is difficult to represent in other forms. Current importance sampling strategies for image-based illumination have difficulties in the case where both the environment map and the surface BRDF contain important high-frequency detail, for example, when a specular surface is illuminated by an environment map containing small light sources. We introduce the notion of bidirectional importance sampling, in which samples are drawn from the product distribution of both the surface reflectance and the energy in the environment map. Although this makes the sample selection process more expensive, we show significant quality improvements over traditional importance sampling strategies for the same compute time.