cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Stable-to-unstable transition in quantum friction
Creators: name: Oue, Daigo
name: Pendry, J. B.
name: Silveirinha, Mário G.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We investigate the frictional force arising from quantum fluctuations when two dissipative metallic plates are set in a shear motion. While early studies showed that the electromagnetic fields in the quantum friction setup reach nonequilibrium steady states, yielding a time-independent force, other works have demonstrated the failure to attain steady states, leading to instability and time-varying friction under sufficiently low-loss conditions. Here, we develop a fully quantum-mechanical theory without perturbative approximations and unveil the transition from stable to unstable regimes of the quantum friction setup. Due to the relative motion of the plates, their electromagnetic response may be active in some conditions, resulting in optical gain. We prove that the standard fluctuation-dissipation leads to inconsistent results when applied to our system, and, in particular, it predicts a vanishing frictional force. Using a modified fluctuation-dissipation relation tailored for gain media, we calculate the frictional force in terms of the system Green's function, thereby recovering early works on quantum friction. Remarkably, we also find that the frictional force diverges to infinity as the relative velocity of the plates approaches a threshold. This threshold is determined by the damping strength and the distance between the metal surfaces. Beyond this critical velocity, the system exhibits instability, akin to the behaviour of a laser cavity, where no steady state exists. In such a scenario, the frictional force escalates exponentially. Our findings pave the way for experimental exploration of the frictional force in proximity to this critical regime.
description: Accepted for publication in Physical Review Research
Three intermediate-mass YSOs with different properties emerging from the same natal cloud in IRAS 00117+6412
Creators: name: Palau, Aina
name: Sanchez-Monge, A.
name: Busquet, G.
name: Estalella, R.
name: Zhang, Q.
name: Ho, P. T. P.
name: Beltran, M. T.
name: Beuther, H.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We observed with the VLA, PdBI, and SMA the centimeter and millimeter continuum, N2H+(1-0), and CO(2-1) emission associated with a dusty cloud harboring a nascent cluster with intermediate-mass protostars. At centimeter wavelengths we found a strong source, tracing a UCHII region, at the eastern edge of the dusty cloud, with a shell-like structure, and with the near-infrared counterpart falling in the center of the shell. This is presumably the most massive source of the forming cluster. About 15'' to the west of the UCHII region and well embedded in the dusty cloud, we detected a strong millimeter source, MM1, associated with centimeter and near-infrared emission. MM1 seems to be driving a prominent high-velocity CO bipolar outflow, and is embedded in a ridge of dense gas traced by N2H+. We estimated that MM1 is an intermediate-mass source in the Class 0/I phase. About 15'' to the south of MM1, and still more deeply embedded in the dusty cloud, we detected a compact millimeter source, MM2, with neither centimeter nor near-infrared emission, but with water maser emission. MM2 is associated with a clump of N2H+, whose kinematics reveal a clear velocity gradient and additionally we found signposts of infall motions. MM2, being deeply embedded within the dusty cloud, with an associated water maser but no hints of CO outflow emission, is an intriguing object, presumably of intermediate mass. In conclusion, the UCHII region is found at the border of a dusty cloud which is currently undergoing active star formation. Two intermediate-mass protostars in the dusty cloud seem to have formed after the UCHII region and have different properties related to the outflow phenomenon.
description: accepted to Astronomy and Astrophysics
Visible GeV ALP from TeV Vector-like Leptons
Creators: name: de Giorgi, Arturo
name: Zamoro, Marta Fuentes
name: Merlo, Luca
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a model where a GeV axion-like-particle (ALP) is predicted in a large portion of the parameter space due to the presence of explicit Peccei-Quinn symmetry-breaking terms in an exotic leptonic sector. The latter provides a solution to the muon $g-2$ anomaly, within the framework of the Linear Seesaw neutrino mechanism. The spectrum is extended by a complex scalar singlet only transforming under the Peccei-Quinn symmetry, which generates the ALP. Its couplings with fermions can continuously span over many orders of magnitude, which constitutes a specific feature of this model in contrast to generic ultraviolet constructions. Interestingly, these couplings are suppressed by the ALP characteristic scale that can be as low as the TeV scale, which represents a novel feature of the model and opens up to several phenomenological consequences.
description: 50 pages, 13 figures, 9 tables
Klimawandel - Handlungsempfehlungen für Bauherrschaften (D / F / I)
Creators: name: Büttner, Sina
name: Stampfli, Janine
name: Domingo Irigoyen, Silvia
name: Settembrini, Gianrico
name: Schrader, Björn
Publisher: name: Zenodo
Year: 2021

description: Kein Abstract vorhanden
description: + ID der Publikation: hslu_85896 + Art des Beitrages: Leitfaden + Sprache: Deutsch + Bemerkungen: Wie mit Silvio Gruber heute Vormittag besprochen, erstelle ich hier diesen PPDB Eintrag, da auf LORY keine Dateien ausgetauscht werden können. + Letzte Aktualisierung: 2021-11-02 16:39:26
Studies related to the Veratrum alkaloids : the total synthesis of C-nor-D-homo steriod analogue.
Creators: name: By, William Arnold
Publisher: name: University of British Columbia
Year: 2011

description: A sequence leading to the total synthesis of trans-anti-trans- and trans-syn-cis-C-nor-2-methoxy-8,11-diketo-10a-methyl-4b,5,6,6a,7,8,9,10,10a,10b,11-undecahydrochrysene (LXXXI and LXXXII,respectively) from the known compound, 2-methoxy-8-keto-10a-methyl-5,6,8,9, 10,10a,11,12-octahydrochrysene (XLIII), is described. Oxidation of trans-anti-trans-2-methoxy-8β-acetoxy-10a-methyl-4b,5,6,6as7,8,9,10,10a,10b,11,12-dodecahydrochrysene (LXV) by means of t-butyl chromate led mainly to the 12-keto derivative (LXVIII). An olefinic bond at the 11,12 position (LXXI) was introduced by mild reduction of LXVIII with sodium borohydride followed by dehydration with phosphorus pentoxide. Subsequent reaction at the olefinic linkage by osmium tetroxide provided mainly the β-diol LXXII which upon treatment with periodic acid gave trans-anti-trans-11 ,12-seco-11,12-dioxo-2-methoxy-8β-acetoxy-10a-methyl-4b,5,6,6a,7,8,9, 10,10a,10b11,12-dodecahydrochry-sene (LXXIV). Intramolecular aldol condensation of IXXIV with sodium hydroxide gave the C-nor-D-homo diol aldehyde LXXIX. Oxidation of the latter with Jones reagent followed by deformylacion of the resulting diketo aldehyde IXXX provided the isomeric diketones LXXXI and LXXXII. It is felt that these latter substances show promise as useful intermediates for the total synthesis of Veratrum alkaloids. In another sequence designed as a model for the subsequent elaboration of LXXXI and LXXXII to the Veratrum alkaloid system, trans-anti-trans-anti-2-keto-8β-hydroxy-10a-methyl -2,3,4,4a, 4b, 5,6, 6a,7, 8,9,10,10a,10b,11,12-hexadecahydrochrysene (XCII) was methylated at C-1via the pyrrolidyl dienamine XCIII. A detailed discussion of the nuclear magnetic resonance spectra of the hydrochrysene compounds is also presented.
BagStacking: An Integrated Ensemble Learning Approach for Freezing of Gait Detection in Parkinson's Disease
Creators: name: Cohen, Seffi
name: Rokach, Lior
Publisher: name: arXiv
Year: 2024
Subjects: subject: Signal Processing (eess.SP)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: This paper introduces BagStacking, a novel ensemble learning method designed to enhance the detection of Freezing of Gait (FOG) in Parkinson's Disease (PD) by using a lower-back sensor to track acceleration. Building on the principles of bagging and stacking, BagStacking aims to achieve the variance reduction benefit of bagging's bootstrap sampling while also learning sophisticated blending through stacking. The method involves training a set of base models on bootstrap samples from the training data, followed by a meta-learner trained on the base model outputs and true labels to find an optimal aggregation scheme. The experimental evaluation demonstrates significant improvements over other state-of-the-art machine learning methods on the validation set. Specifically, BagStacking achieved a MAP score of 0.306, outperforming LightGBM (0.234) and classic Stacking (0.286). Additionally, the run-time of BagStacking was measured at 3828 seconds, illustrating an efficient approach compared to Regular Stacking's 8350 seconds. BagStacking presents a promising direction for handling the inherent variability in FOG detection data, offering a robust and scalable solution to improve patient care in PD.
A dedicated Chandra ACIS observation of the central compact object in the Cassiopeia A supernova remnant
Creators: name: Pavlov, G. G.
name: Luna, G. J. M.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present results of a recent Chandra X-ray Observatory observation of the central compact object (CCO) in the supernova remnant Cassiopeia A. This observation was obtained in an instrumental configuration that combines a high spatial resolution with a minimum spectral distortion, and it allowed us to search for pulsations with periods longer than 0.68 s. We found no evidence of extended emission associated with the CCO, nor statistically significant pulsations (the 3-sigma upper limit on pulsed fraction is about 16%). The fits of the CCO spectrum with the power-law model yield a large photon index, Gamma\approx 5, and a hydrogen column density larger than that obtained from the SNR spectra. The fits with the blackbody model are statistically unacceptable. Better fits are provided by hydrogen or helium neutron star atmosphere models, with the best-fit effective temperature kT_{eff}^\infty \approx 0.2 keV, but they require a small star's radius, R = 4 - 5.5 km, and a low mass, M < 0.8 M_sol. A neutron star cannot have so small radius and mass, but the observed emission might emerge from an atmosphere of a strange quark star. More likely, the CCO could be a neutron star with a nonuniform surface temperature and a low surface magnetic field (the so-called anti-magnetar), similar to three other CCOs for which upper limits on period derivative have been established. The bolometric luminosity, L_{bol}^\infty \sim 6\times 10^{33} erg s^{-1}, estimated from the fits with the hydrogen atmosphere models, is consistent with the standard neutron star cooling for the CCO age of 330 yr. The origin of the surface temperature nonuniformity remains to be understood; it might be caused by anisotropic heat conduction in the neutron star crust with very strong toroidal magnetic fields.
description: 12 pages, including 7 figures; the end of Section 3.3 revised; accepted by ApJ
Tax benefits for individuals and extent of their use in Estonia during 2007-2009
Creators: name: Buldas, Velda
name: Sander, Priit
name: Kantshukov, Mark
Publisher: name: MATTIMAR OÜ
Year: 2012
Subjects: tax benefits; tax exemptions; tax system; Estonia

description: In this paper an overview of tax benefits granted by Estonian legal acts is given, and
extent of tax benefits use by resident natural persons using the data from databases
of Estonian Tax and Customs Board (ETCB) is analyzed. Also the possibility of tax
benefits classification is considered and to whom and on which purposes stated tax
benefits are addressed is analyzed. Research based on three years data shows that in
Estonia tax benefits for individuals are widely used. On average uncollected
amounts of tax due to tax benefits approximately equal 9% of the state budget
revenues. Large amount of tax benefits is not a negative indicator per se but they aid
distributed incomes to reach people who really need those benefits. In opposite case
tax benefits are not reasoned but they rather create additional administrative
workload. Talking about Estonian tax system roughly half of tax benefits is
addresses to people who belong to low income stratum, at the same time remarkable
proportion of benefits may be directed to middle-class and wealthy people.
description: Estonian Discussions on Economic Policy, Vol 19, No 1 (2011)
Double helicity asymmetry in π0 production in polarized proton-proton collisions at √s =510 GeV with PHENIX mid-rapidity spectrometor
Creators: name: Yoon, Inseok
Publisher: name: Zenodo
Year: 2015
Subjects: phenix
helicity
asymmetry
polarization
π0
spin

description: PHENIX measurement of longitudinally double helicity asymmetry (ALL) in inclusive π0 production at mid-rapidity from p+p collisions at √s = 510 GeV from the 2012/2013 RHIC runs is presented in this work. The spin contribution of gluon (∆G) might explain the missing part of the proton spin and measuring ∆G, the ultimate goal of the dissertation.
RISnet: A Domain-Knowledge Driven Neural Network Architecture for RIS Optimization with Mutual Coupling and Partial CSI
Creators: name: Peng, Bile
name: Besser, Karl-Ludwig
name: Shen, Shanpu
name: Siegismund-Poschmann, Finn
name: Raghunath, Ramprasad
name: Mittleman, Daniel
name: Jamali, Vahid
name: Jorswieck, Eduard A.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Information Theory (cs.IT)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Space-division multiple access (SDMA) plays an important role in modern wireless communications. Its performance depends on the channel properties, which can be improved by reconfigurable intelligent surfaces (RISs). In this work, we jointly optimize SDMA precoding at the base station (BS) and RIS configuration. We tackle difficulties of mutual coupling between RIS elements, scalability to more than 1000 RIS elements, and high requirement for channel estimation. We first derive an RIS-assisted channel model considering mutual coupling, then propose an unsupervised machine learning (ML) approach to optimize the RIS with a dedicated neural network (NN) architecture RISnet, which has good scalability, desired permutation-invariance, and a low requirement for channel estimation. Moreover, we leverage existing high-performance analytical precoding scheme to propose a hybrid solution of ML-enabled RIS configuration and analytical precoding at BS. More generally, this work is an early contribution to combine ML technique and domain knowledge in communication for NN architecture design. Compared to generic ML, the problem-specific ML can achieve higher performance, lower complexity and permutation-invariance.
description: 13 pages, 11 figures
Wirtschaftliche Hindernisse für den Beitritt der Tschechischen Republik zur Eurozone. Economic barriers of the Czech Republic’s euro-area accession
Creators: name: Helisek, Mojmir
Publisher: name: MATTIMAR OÜ
Year: 2012
Subjects: euro; euro area; euro area enlargement; maastricht criteria; nomial and real convergence; exchange rate stability; excessive deficit procedure

description: The date of introduction of the euro in the Czech Republic has not been set. The
Czech economy fulfils the inflation and interest rate convergence criteria, as well as
the government debt criterion. The exchange rate stability criterion will be most
likely fulfilled. The Czech economy possesses a high level of real convergence in
respect of the euro area. Due to the economic recession, the government deficit
criterion will probably not be fulfilled by 2012. The date of introduction of the euro
in the Czech Republic is therefore postponed to 2015 at the earliest. The main
reason for adopting the single currency is the growing interconnection between the
Czech and the euro area economies. The exchange rate of the Czech crown to the
euro has a higher stability than the exchange rate of the euro to the dollar, however,
a long-term appreciation of the crown’s exchange rate weakens the competitiveness
of the Czech exporters. The financial crisis and the recession have only complicated
and postponed the adoption of the euro, but they have revealed no reasons to refuse
the adoption.
description: Estonian Discussions on Economic Policy, Vol 19, No 1 (2011)
Hypothesis test for normal mixture models: The EM approach
Creators: name: Chen, Jiahua
name: Li, Pengfei
Publisher: name: arXiv
Year: 2009
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62F03 (Primary) 62F05 (Secondary)

description: Normal mixture distributions are arguably the most important mixture models, and also the most technically challenging. The likelihood function of the normal mixture model is unbounded based on a set of random samples, unless an artificial bound is placed on its component variance parameter. Moreover, the model is not strongly identifiable so it is hard to differentiate between over dispersion caused by the presence of a mixture and that caused by a large variance, and it has infinite Fisher information with respect to mixing proportions. There has been extensive research on finite normal mixture models, but much of it addresses merely consistency of the point estimation or useful practical procedures, and many results require undesirable restrictions on the parameter space. We show that an EM-test for homogeneity is effective at overcoming many challenges in the context of finite normal mixtures. We find that the limiting distribution of the EM-test is a simple function of the $0.5χ^2_0+0.5χ^2_1$ and $χ^2_1$ distributions when the mixing variances are equal but unknown and the $χ^2_2$ when variances are unequal and unknown. Simulations show that the limiting distributions approximate the finite sample distribution satisfactorily. Two genetic examples are used to illustrate the application of the EM-test.
description: Published in at http://dx.doi.org/10.1214/08-AOS651 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Households water quality in O’Kiep-South Africa and community perception of related health risks
Creators: name: Ntwampe, Seteno Karabo Obed
Publisher: name: figshare
Year: 2021
Subjects: subject: 90799 Environmental Engineering not elsewhere classified
subject: FOS: Environmental engineering

description: South Africa faced challenges related to potable water quality that has periodically deteriorated,coupled with inconsistent supply of tap water (TW) to households. These challenges are a primaryexasperation in the arid O’Kiep region, where the community has few alternatives regarding drinkablewater sources. The aim of this study was to assess the quality of drinking TW supplied to theO’Kiep community, focusing on health risks associated with the ingestion of such water. The studyincluded both the quantitative assessment of water quality parameters and a qualitative assessmentof adverse human health outcomes experienced by the residents. Furthermore, disease patternswhich were associated with ingestion of supplied water were also identified and subjected toappropriate statistical data analyses. Due to the inadequate drinking water supply and shortages inO’Kiep, households often are dependent on water tankers and commercially bottled water, amongstother potential sources of drinkable water. Water samples (n = 53) from O’Kiep’ drinking water supplysystem (DWSS), that is, n = 3 were collected from source and (n = 50) point-of-use (TW) whilethe questionnaires were simultaneously administered in households. None of the statistical modelssuggested physicochemical properties as predictors of any of the health symptoms. Approximately,88% of community members indicated that the water supplied is often turbid, while a high numberof people with teeth discolouration (72%) are living in the area and experience diarrhoea-likesymptoms, which are likely to be associated with the ingestion of toxin-contaminated water. Thiswas confirmed by some physiochemical parameters quantified, that is, low dissolved oxygen of2.0 mg/L, a high electrical conductivity of 595 mg/L, and SO42– and chlorine concentrations of 557 and47.1 mg/L, respectively, which were not within the range prescribed for drinking water guidelines.Furthermore, a positive confirmatory test indicated the presence of toxins in the water. Therefore,regular monitoring and evaluation of DWSS is essential for this vulnerable community
The role of family business in Estonian economy. Pereettevõtte rollist Eesti majanduses
Creators: name: Kirsipuu, Maret
Publisher: name: MATTIMAR OÜ
Year: 2012
Subjects: family business entrepreneur; family business; family entrepreneurship

description: Family businesses have a remarkable role in the world economy; their role in
economies has been investigated by many researchers. This paper seeks to study the
findings of research conducted over 2008…2011 in Estonia in the field of family
businesses and family business entrepreneurs. This research attempts to define
development and sustainability of family businesses in Estonian economy. After
Estonia regained independence in 1991, private entrepreneurship started to develop,
and many people, particularly in rural areas, set up a family enterprise. After
Estonia’s accession to the European Union in 2004, family business activity boosted
further still. Until 2007, family business activity was rather domestic market
focused; after Estonia was acceded to the Schengen visa area, they started to
successfully sell products and services outside Estonia. The research findings can be
used either for diversifying economic activity of family businesses or for investment
support or in other areas. This research definitely benefits to all enterprising people
who wish to become a family business entrepreneur and who wish to set up a strong
and sustainable family business
description: Estonian Discussions on Economic Policy, Vol 19, No 1 (2011)
Signal Response Model in PandaX-4T
Creators: name: Luo, Yunyang
name: Bo, Zihao
name: Zhang, Shibo
name: Abdukerim, Abdusalam
name: Cheng, Chen
name: Chen, Wei
name: Chen, Xun
name: Chen, Yunhua
name: Cheng, Zhaokan
name: Cui, Xiangyi
name: Fan, Yingjie
name: Fang, Deqing
name: Fu, Changbo
name: Fu, Mengting
name: Geng, Lisheng
name: Giboni, Karl
name: Gu, Linhui
name: Guo, Xuyuan
name: Han, Chencheng
name: Han, Ke
name: He, Changda
name: He, Jinrong
name: Huang, Di
name: Huang, Yanlin
name: Huang, Zhou
name: Hou, Ruquan
name: Ji, Xiangdong
name: Ju, Yonglin
name: Li, Chenxiang
name: Li, Jiafu
name: Li, Mingchuan
name: Li, Shu
name: Li, Shuaijie
name: Lin, Qing
name: Liu, Jianglai
name: Lu, Xiaoying
name: Luo, Lingyin
name: Ma, Wenbo
name: Ma, Yugang
name: Mao, Yajun
name: Shaheed, Nasir
name: Meng, Yue
name: Ning, Xuyang
name: Qi, Ningchun
name: Qian, Zhicheng
name: Ren, Xiangxiang
name: Shang, Changsong
name: Shang, Xiaofeng
name: Shen, Guofang
name: Si, Lin
name: Sun, Wenliang
name: Tan, Andi
name: Tao, Yi
name: Wang, Anqing
name: Wang, Meng
name: Wang, Qiuhong
name: Wang, Shaobo
name: Wang, Siguang
name: Wang, Wei
name: Wang, Xiuli
name: Wang, Zhou
name: Wei, Yuehuan
name: Wu, Mengmeng
name: Wu, Weihao
name: Xia, Jingkai
name: Xiao, Mengjiao
name: Xiao, Xiang
name: Xie, Pengwei
name: Yan, Binbin
name: Yan, Xiyu
name: Yang, Jijun
name: Yang, Yong
name: Yu, Chunxu
name: Yuan, Jumin
name: Yuan, Ying
name: Yuan, Zhe
name: Zeng, Xinning
name: Zhang, Dan
name: Zhang, Minzhen
name: Zhang, Peng
name: Zhang, Shu
name: Zhang, Tao
name: Zhang, Yingxin
name: Zhang, Yuanyuan
name: Zhao, Li
name: Zheng, Qibin
name: Zhou, Jifang
name: Zhou, Ning
name: Zhou, Xiaopeng
name: Zhou, Yong
name: Zhou, Yubo
Publisher: name: arXiv
Year: 2024
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: PandaX-4T experiment is a deep-underground dark matter direct search experiment that employs a dual-phase time projection chamber with a sensitive volume containing 3.7 tonne of liquid xenon. The detector of PandaX-4T is capable of simultaneously collecting the primary scintillation and ionization signals, utilizing their ratio to discriminate dark matter signals from background sources such as gamma rays and beta particles. The signal response model plays a crucial role in interpreting the data obtained by PandaX-4T. It describes the conversion from the deposited energy by dark matter interactions to the detectable signals within the detector. The signal response model is utilized in various PandaX-4T results. This work provides a comprehensive description of the procedures involved in constructing and parameter-fitting the signal response model for the energy range of approximately 1 keV to 25 keV for electronic recoils and 6 keV to 90 keV for nuclear recoils. It also covers the signal reconstruction, selection, and correction methods, which are crucial components integrated into the signal response model.
Thermodynamics of the Three-dimensional Black Hole with a Coulomb-like Field
Creators: name: Larranaga, Alexis
name: Garcia, Luz Angela
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper, we study the thermodynamical properties of the (2+1)dimensional black hole with a Coulomb-like electric field and the differential form of the first law of thermodynamics is derived considering a virtual displacement of its event horizon. This approach shows that it is possible to give a thermodynamical interpretation to the field equations near the horizon. The Lambda=0 solution is studied and its interesting thermodynamical properties are commented.
description: 8 pages
Novel quantum spin liquid ground state in the trimer rhodate Ba$_4$NbRh$_3$O$_{12}$
Creators: name: Bandyopadhyay, Abhisek
name: Lee, S.
name: Adroja, D. T.
name: Stenning, G. B. G.
name: Berlie, Adam
name: Lees, M. R.
name: Saha, R. A.
name: Takegami, D.
name: Melendez-Sans, A.
name: Poelchen, G.
name: Yoshimura, M.
name: Tsuei, K. D.
name: Hu, Z.
name: Kao, Cheng-Wei
name: Huang, Yu-Cheng
name: Chan, Ting-Shan
name: Cho, Kwang-Yong
Publisher: name: arXiv
Year: 2024
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Frustrated magnets offer a plethora of exotic magnetic ground states, including quantum spin liquids (QSLs), in which enhanced quantum fluctuations prevent a long-range magnetic ordering of the strongly correlated spins down to lowest temperature. Here we have investigated the trimer based mixed valence hexagonal rhodate Ba$_4$NbRh$_3$O$_{12}$ using a combination of dc and ac magnetization, electrical resistivity, specific heat, and muon spin rotation/relaxation ($μ$SR) measurements. Despite the substantial antiferromagnetic exchange interactions, as evident from the Weiss temperature ($θ_{\mathrm{W}}\sim -35$ to -45 K), among the Rh-local moments, neither long-range magnetic ordering nor spin-freezing is observed down to at least 50 mK, in ac-susceptibility, specific heat and ZF-$μ$SR measurements (down to 0.26 K). We ascribe the absence of any magnetic transition to enhanced quantum fluctuations as a result of geometrical frustration arising out of the edge-sharing equilateral Rh-triangular network in the structure. Our longitudinal-field $μ$SR result evidences persistent spin fluctuations down to 0.26~K, thus stabilizing a dynamic QSL ground state in Ba$_4$NbRh$_3$O$_{12}$. Furthermore, the magnetic specific heat ($C_{\mathrm{m}}$) data at low-$T$ reveal a significant $T$-linear contribution plus a quadratic $T$-dependence. A $T$-linear behavior is evocative of gapless spin excitations, while the $T^2$-term of $C_{\mathrm{m}}$ may indicate the Dirac QSL phenomenology of the spinon excitations with a linear dispersion.
description: 21 pages, 11 figures
Economic and legal aspects of the patent litigation in the European Union: developments and perspectives. Patendivaidluste lahendamise majandus-õiguslikke küsimusi Euroopa Liidus: arengud ja perspektiivid
Creators: name: Kukrus, Ants
name: Kartus, Raul
Publisher: name: MATTIMAR OÜ
Year: 2012
Subjects: European Patent Litigation Agreement (EPLA); Unified Patent Litigation System (UPLS); European and European Union Patents Court (EEUPC); Agreement on the European and Community Patents Court; European Union patent (EU patent); European Court of Justice (E

description: This article introduces an ongoing process of creation of the Unified Patent
Litigation System (UPLS) in Europe and describes shortly the structure of the
proposed European and European Union Patents Court (EEUPC). Current patent
litigation systems in various European countries and deficiencies in the current
systems are also described. The EEUPC will deal with the infringement and validity
cases of European patents and EU patents. This article contains a detailed list of
court actions over which EEUPC has exclusive jurisdiction, benefits of the new
system as well as stakeholders’ concerns.
description: Estonian Discussions on Economic Policy, Vol 19, No 1 (2011)
Statistical Model for a Complete Supernova Equation of State
Creators: name: Hempel, Matthias
name: Schaffner-Bielich, Jürgen
Publisher: name: arXiv
Year: 2009
Subjects: subject: Nuclear Theory (nucl-th)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: A statistical model for the equation of state (EOS) and the composition of supernova matter is presented with focus on the liquid-gas phase transition of nuclear matter. It consists of an ensemble of nuclei and interacting nucleons in nuclear statistical equilibrium. A relativistic mean field model is applied for the nucleons. The masses of the nuclei are taken from nuclear structure calculations which are based on the same nuclear Lagrangian. For known nuclei experimental data is used directly. Excluded volume effects are implemented in a thermodynamic consistent way so that the transition to uniform nuclear matter at large densities can be described. Thus the model can be applied at all densities relevant for supernova simulations, i.e. rho=10^5 - 10^15 g/cm^3, and it is possible to calculate a complete supernova EOS table. The model allows to investigate the role of shell effects, which lead to narrow-peaked distributions around the neutron magic numbers for low temperatures. At larger temperatures the distributions become broad. The significance of the statistical treatment and the nuclear distributions for the composition is shown. We find that the contribution of light clusters is very important and is only poorly represented by alpha-particles alone. The results for the EOS are systematically compared to two commonly used models for supernova matter which are based on the single nucleus approximation. Apart from the composition, in general only small differences of the different EOSs are found. The differences are most pronounced around the (low-density) liquid-gas phase transition line where the distribution of light and intermediate clusters has an important effect. Possible extensions and improvements of the model are discussed.
description: 33 pages, 22 pages
A Bayesian Approach to OOD Robustness in Image Classification
Creators: name: Kaushik, Prakhar
name: Kortylewski, Adam
name: Yuille, Alan
Publisher: name: arXiv
Year: 2024
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: An important and unsolved problem in computer vision is to ensure that the algorithms are robust to changes in image domains. We address this problem in the scenario where we have access to images from the target domains but no annotations. Motivated by the challenges of the OOD-CV benchmark where we encounter real world Out-of-Domain (OOD) nuisances and occlusion, we introduce a novel Bayesian approach to OOD robustness for object classification. Our work extends Compositional Neural Networks (CompNets), which have been shown to be robust to occlusion but degrade badly when tested on OOD data. We exploit the fact that CompNets contain a generative head defined over feature vectors represented by von Mises-Fisher (vMF) kernels, which correspond roughly to object parts, and can be learned without supervision. We obverse that some vMF kernels are similar between different domains, while others are not. This enables us to learn a transitional dictionary of vMF kernels that are intermediate between the source and target domains and train the generative model on this dictionary using the annotations on the source domain, followed by iterative refinement. This approach, termed Unsupervised Generative Transition (UGT), performs very well in OOD scenarios even when occlusion is present. UGT is evaluated on different OOD benchmarks including the OOD-CV dataset, several popular datasets (e.g., ImageNet-C [9]), artificial image corruptions (including adding occluders), and synthetic-to-real domain transfer, and does well in all scenarios outperforming SOTA alternatives (e.g. up to 10% top-1 accuracy on Occluded OOD-CV dataset).
Einige kritische Betrachtungen zu neuesten Entwicklungen in der Estnischen Wirtschaftspolitik. Mõned kriitilised märkused Eesti majanduspoliitika viimastele arengutele
Creators: name: Raudjärv, Matti
Publisher: name: MATTIMAR OÜ
Year: 2012

description: The paper contains a brief treatment of the economic crisis in Estonia, associating it critically with the general economic situation and reasons. The issues of unemployment, increase in prices and several other important areas are under review. Adoption of euro and the price dynamics in Estonia are treated separately. In the opinion of the author the price increases are not caused by the euro but by the greed for profits and irresponsibility of businesses and traders. National institutions do not view economic policy as an integrated activity either but rather see it as behaviour and choices appropriate for a particular political party. Situation in quite a few areas is critically evaluated, including the activities of the Estonian political parties in power. Organisation of the recent elections of the Estonian Riigikogu (Parliament) is evaluated and suggestions are made both for improvement of the organisation of elections in the spirit of democracy and for the related needs for further development of the Estonian national economy.
description: Estonian Discussions on Economic Policy, Vol 19, No 2 (2011)
MEASUREMENT OF THE DOUBLE HELICITY ASYMMETRY IN INCLUSIVE π0 PRODUCTION IN POLARIZED PROTON-PROTON COLLISIONS AT √s = 510 GeV
Creators: name: Guragain, Hari
Publisher: name: Zenodo
Year: 2015
Subjects: phenix
helicity
gluon
polarization
asymmetry
π0

description: In this dissertation, the results of ALL in π0 production from the data collected in 2013 at center of mass energy = 510 GeV are presented
Competition policy in infrastructure specific sectors in the Estonian case: entwining of natural monopoly and universal service. Konkurentsipoliitika infrastruktuursetes erandvaldkondades Eesti näitel: loomuliku monopoli ja universaalteenuse põimumine
Creators: name: Sepp, Jüri
name: Eerma, Diana
Publisher: name: MATTIMAR OÜ
Year: 2012

description: There is a growing consensus that the successful development of infrastructure specific sectors depends a lot on the adaption of appropriate public policies and the effective implementation of these policies. The way how regulation is implemented plays an important role in infrastructure development and use. In the article the means of regulating economic policy in Estonia are systematized and evaluated looking at practices regarding both natural monopoly and universal service.
description: Estonian Discussions on Economic Policy, Vol 19, No 2 (2011)
Mild and highly efficient deacetylation of acetamido and acetoxy coumarins: A convenient and expeditious synthesis of substituted 3-aminocoumarins
Creators: name: Krajňáková, Jana
name: Joniak, Jakub
name: Putala, Martin
name: Górová, Renáta
name: Jurdáková, Helena
name: Stankovičová, Henrieta
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Biochemistry
subject: Molecular Biology
subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences

description: A convenient protocol for efficient and cost-effective method for synthesis of substituted 3-aminocoumarins has been developed. The synthetic route involves expeditious and fast quantitative deacetylation of readily available acetamido derivative under anhydrous acidic conditions, employing thionyl chloride in methanol, without formation of undesired substituted 3-hydroxycoumarins. The method is suitable for derivatives bearing electron-donating as well as electron-withdrawing groups at position 7 of the coumarin scaffold. Under these conditions, a series of acetoxy substituted 3-dialkylaminocoumarins has been also successfully deacetylated to afford easily isolable corresponding hydroxy derivatives in high yields.
A Free Energy Model for the Plateau Shear Modulus in Thermosensitive Microgel Suspensions
Creators: name: Bergman, Maxime
name: Xu, Yixuan
name: Díaz, José Muñéton
name: Chi, Zhang
name: Mason, Thomas G.
name: Scheffold, Frank
Publisher: name: arXiv
Year: 2024
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Polymer microgels exhibit intriguing macroscopic flow properties arising from their unique microscopic structure. Microgel colloids usually comprise a crosslinked polymer network with a radially decaying density profile, resulting in a dense core surrounded by a fuzzy corona. Notably, microgels synthesized from poly(N-isopropyl acrylamide) (PNIPAM) are thermoresponsive, capable of adjusting their size and density profile based on temperature. Above the lower critical solution temperature ($T_\text{LCST} \sim 33$ $^\circ$C), the microgel's polymer network collapses, expulsing water through a reversible process. Conversely, below $33$ $^\circ$C, the microgel's network swells, becoming highly compressible and allowing overpacking to effective volume fractions exceeding one. Under conditions of dense packing, microgels undergo deformation in distinct stages: corona compression and faceting, interpenetration, and finally, isotropic compression. Each stage exhibits a characteristic signature in the dense microgel suspensions' yield stress and elastic modulus. Here, we introduce a model for the linear elastic shear modulus by minimizing a quasi-equilibrium free energy, encompassing all relevant energetic contributions. We validate our model by comparing its predictions to experimental results from oscillatory shear rheology tests on microgel suspensions at different densities and temperatures. Our findings demonstrate that combining macroscopic rheological measurements with the model allows for temperature-dependent characterization of polymer interaction parameters.
description: 24 pages, 4 figures. Langmuir (online, February 3, 2025)
The redshift evolution of oxygen and nitrogen abundances in emission-line SDSS galaxies
Creators: name: Thuan, T. X.
name: Pilyugin, L. S.
name: Zinchenko, I. A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The oxygen and nitrogen abundance evolutions with redshift and galaxy stellar mass in emission-line SDSS galaxies are investigated. This is the first such study for nitrogen abundances, and it provides an additional constraint for the study of the chemical evolution of galaxies. We have devised a criterion to recognize and exclude from consideration AGNs and star-forming galaxies with large errors in the line flux measurements. To select star-forming galaxies with accurate line fluxes measurements, we require that, for each galaxy, the nitrogen abundances derived with various calibrations based on different emission lines agree. Using this selection criterion, subsamples of star-forming galaxies have been extracted from catalogs of the MPA/JHU group. We found that the galaxies of highest masses, those with masses > 10^11.2 M_sun, have not been enriched in both oxygen and nitrogen over the last 3 Gyr: they have formed their stars in the so distant past that these have returned their nucleosynthesis products to the interstellar medium before z=0.25. The galaxies in the mass range from 10^11.0 M_sun to 10^11.2 M_sun do not show an appreciable enrichment in oxygen, but do show some enrichment in nitrogen: they also formed their stars before z=0.25 but later in comparison to the galaxies of highest masses; these stars have not returned nitrogen to the interstellar medium before z=0.25 because they have not had enough time to evolve. This suggests that stars with lifetimes of 2-3 Gyr contribute to the nitrogen production. Finally, galaxies with masses < 10^11 M_sun show enrichment in both oxygen and nitrogen during the last 3 Gyr: they have undergone appreciable star formation and have converted up to 20% of their mass into stars over this period.
description: 43 pages, 15 figures, accepted for publication in the Astrophysical Journal
Density Functional Theory of Material Design: Fundamentals and Applications -- I
Creators: name: Singh, Prashant
name: Harbola, Manoj K
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: This article is part-I of a review of density-functional theory (DFT) that is the most widely used method for calculating electronic structure of materials. The accuracy and ease of numerical implementation of DFT methods has resulted in its extensive use for materials design and discovery and has thus ushered in the new field of computational material science. In this article we start with an introduction to Schrödinger equation and methods of its solutions. After presenting exact results for some well-known systems, difficulties encountered in solving the equation for interacting electrons are described. How these difficulties are handled using the variational principle for the energy to obtain approximate solutions of the Schrödinger equation is discussed. The resulting Hartree and Hartree-Fock theories are presented along with results they give for atomic and solid-state systems. We then describe Thomas-Fermi theory and its extensions which were the initial attempts to formulate many-electron problem in terms of electronic density of a system. Having described these theories, we introduce modern density functional theory by discussing Hohenberg-Kohn theorems that form its foundations. We then go on to discuss Kohn-Sham formulation of density-functional theory in its exact form. Next, local density approximation is introduced and solutions of Kohn-Sham equation for some representative systems, obtained using the local density approximation, are presented. We end part-I of the review describing the contents of part-II.
description: 44 pages, 3 figures, 5 tables
Bullying at work: do industries differ in the Estonian case? Kas psühholoogilise töövägivalla levik on majandus-sektorites erinev: olukord Eestis?
Creators: name: Tambur, Merle
name: Vadi, Maaja
Publisher: name: MATTIMAR OÜ
Year: 2012

description: The bullying at work has not so far analyzed in Estonia – its dispersal, causes and impact have not studied, while in the countries with long democratic traditions it has been the actual problem of work context for two decades. The current study examines the prevalence of workplace bullying in Estonian organizations and the extent of the problem by industries because bullying may put impact on the employees´ efficiency. The sample consists of 1941 respondents which covers 59 organizations across Estonia and represents in all over 30 000 employee and the unemployed. The results reveal that bullying poses a serious problem in Estonia. According to Leymann´s criteria (1996) at least one negative act per week with a duration of at least 6 months, has been reported by 23,44% of respondents. Although, it came out that bullying is not sector-specific problem in Estonia, several and different industries are vulnerable from bullying.
description: Estonian Discussions on Economic Policy, Vol 19, No 2 (2011)
Personal income tax in Estonia – who’s burden? Füüsilise isiku tulumaks – kelle koorem?
Creators: name: Trasberg, Viktor
Publisher: name: MATTIMAR OÜ
Year: 2012

description: Despite many common features, the personal income tax (PIT) systems are broadly country specific and designed in accordance with society’s preferences. The paper focuses on PIT developments during the last decade in Estonia. There will be considered income dynamics and allocation of taxpayers to income groups. Also will be analyzed PIT burden distribution across the income earners groups and explained main factors, influencing effective tax rates. Also will be given overview and explained dynamics of various deductions, which adjust actual tax burden. Despite the existing flat tax system in Estonia, different deductions are implementing significant progression to the actual tax system.
description: Estonian Discussions on Economic Policy, Vol 19, No 2 (2011)