Miracle-dz/UniFAR-FTUs huggingface dataset:
The Effect of Immigration on the German Housing Market

This study provides evidence of the causal impact of immigration on housing prices and rents using an extensive dataset from Germany that covers 382 administrative districts over the period 2004−2020. Employing a panel-data approach and a manually constructed Bartik instrument, we show that international migration has a significantly positive short-term effect on flat prices and rents. House prices are not significantly affected. We estimate that an increase in international migration of 1% of the initial district population causes a hike in flat prices of up to 3% as well as a hike in flat rents of about 1%. The increase in flat prices is more than twice as high as this at the lower end of the market, whereas the flat rental market demonstrates a more linear response. We also discover that immigration’s impact on flat prices and rents does not significantly differ across rural and urban areas within the country. JEL
Extremal Point Sets and Gorenstein Ideals

The Hilbert function of a homogeneous ideal in R=k[x0 , . , xn], k a field, is a much studied object. This is not surprising since the Hilbert function encodes important algebraic, combinatorial, and geometric information about the ideal. The fact that recent computer algebra developments have made the Hilbert function computable has not only sustained interest in them but sparked interest in many new questions about them. In this paper, we will concentrate on the Hilbert functions which are the Hilbert functions of points in P. From [11], we know that this is the same as studying 0-dimensional differentiable O-sequences (equivalently, the Hilbert functions of graded artinian quotients of k[x1 , ., xn]). In our earlier paper [9], we began a discussion of n-type vectors and showed that they were in 1 1 correspondence with Hilbert functions of doi:10.1006 aima.1998. 1889, available online at http: www.idealibrary. com on
An analysis of the variable radial velocity of alpha cygni

On the basis of 447 radial velocities obtained at the Lick Observatory by Paddock in the years 1927--1935, an attempt is made to discover the nature of the semiregular variability of . cap alpha. Cygni (A2 Ia). Harmonic analysis of the 144 velocities obtained in 1931 suggests that this variability is due to the simultaneous excitation of many discrete pulsation modes. The amplitudes and periods of these modes are then determined by least-squares fitting to all the data, and a final solution is obtained that comprises 16 terms with periods from 6.9 to 100.8 days. All terms are found to have highly significant amplitudes, and most terms also pass a test of the stability of their amplitudes and phases. Reasons are given for believing that most terms represent nonradial oscillations, and this leads to the suggestion that the resulting surface motions are to be identified with macroturbulence. An argument is also given for believing that the pulsational instability persists down to periods at which atmospheric oscillations become progressive, and this leads to the suggestion that such waves are observed as microturbulence and give rise to the observed mass loss. The importance of further monitoring of the variability of supergiants is stressed.more » (AIP)« less
Loewy matrix, koszul cone and applications

1 Loewy matrix and Koszul cone By a graded algebra over a field k we always mean an algebra A = A. + A1 + 0 . generated by A. and Al, that is, for each i, j > 0, AiAj = Ai+j such that each At is a finite dimensional vector space over t and A. is a finite product of copies of k. So 1 E A0 and we have 1 = el + + en as a decomposition of 1 as a sum of the orthogonal primitive idempotents. Note that A. is semisimple, so A0 = S1 @ S2 @ . @ Sn, where Si are pairwise nonisomorphic graded simple modules, they are called the vertex simple modules. Assume in addition that A is finite dimensional. Let rA = A1 + A2 + . be the radical of A. Then there is an integer m, called the level of A, such that
Does Exposure to Interpersonal Trauma Influence the Relationship between Shame and Posttraumatic Stress Symptoms?

ABSTRACT Although shame is a common emotional response to trauma exposure, it may be precipitated by distinct trauma types. To our knowledge, our study is the first to investigate the relationship between shame and PTSD symptom severity and whether exposure to at least one interpersonal trauma influences the relationship between shame and PTSD symptoms. One-hundred and fifty-seven participants from Australia, Canada, United States, United Kingdom, and New Zealand completed a series of self-report measures. Although shame was significantly associated with PTSD symptom severity, it was not an independent predictor of PTSD when considering anxiety, depression, trauma history and guilt. Participants exposed to at least one interpersonal traumatic event endorsed higher levels of shame and PTSD compared to those who did not. Interpersonal trauma exposure also moderated the relationship between shame and PTSD. Clinical implications and directions for future research are also discussed.
Speed-Sensorless Control of Induction Motor Drives With a STA-FLL Speed Estimation Scheme

Speed-sensorless control (SSC) techniques enhance the overall reliability while reducing the cost, and thus become attractive in induction motors (IMs). Simplicity and flexibility are the main features that make phase-locked loop (PLL)- and frequency-locked loop (FLL)- based speed estimation schemes stand out among considerable estimation methods. However, many PLL and FLL schemes exhibit a poor estimation accuracy in the cases of acceleration and deceleration (AaD). Accordingly, an adaptive second-order generalized integrator-FLL (SOGI-FLL)-based scheme is introduced. While, the issue of the estimated speed feedback (ESF) in the adaptive SOGI-FLL scheme remains an obstacle. With the above, a speed estimation scheme that combines the super-twisting algorithm with an FLL (STA-FLL) is proposed for the SSC of IM drives in this article. In the proposed STA-FLL scheme, an STA-based quadrature signal generator (STA-QSG) is properly designed, in which the ESF is cancelled to further ensure speed estimation. Moreover, a closed-loop flux observer is adopted in the implementation to enhance the proposed STA-FLL scheme in terms of disturbance mitigation. Experimental tests are performed to validate the proposed STA-FLL scheme.
Dynamic Transmission Mode Selection for Multi-Modal Services

Multi-modal services, which integrate emerging haptic signals with audio-video signals, are expected to further improve user’s immersive experience. However, traditional audio-video communication schemes fail to simultaneously meet various transmission requests of low latency, high reliability, and high throughput. To resolve this problem, based on the existing communication paradigms, a dynamic multi-modal service transmission mode selection strategy is proposed. Firstly, according to different types of multi-modal services, three transmission strategies are proposed to satisfy different transmission requests. And a rule for mode selection and resource allocation is designed. Secondly, an improved multi-objective optimization algorithm based on NSGA3 is proposed to select modes and allocate resources, which improves communication performance as much as possible, and achieves better resource utilization efficiency. Finally, simulation results show the effectiveness of proposed method.
Shear softening in tantalum at megabar pressures

Received 13 July 2010; revised manuscript received 6 September 2010; published 4 October 2010We have experimentally and theoretically investigated the aggregate elasticity of tantalum to pressuresexceeding 1 Mbar. Our inelastic x-ray scattering measurements show a softening in the aggregate shearvelocity in the 90–100 GPa range with typical pressure dependence above 120 GPa. Our calculations suggestthat, in analogy with theoretical predictions on vanadium and niobium, this anomalous behavior is likely dueto the intraband nesting of the Fermi surface that leads to an electronic topological transition and a concomitanttransverse-acoustic-phonon mode softening.DOI: 10.1103/PhysRevB.82. 132101 PACS number s : 62.50. p, 62.30. d, 63.20. kd, 64.70. kd
The trade-off between costs and carbon emissions from economic lot-sizing decisions

Abstract Logistics decisions can have a significant impact on carbon emissions, a driver of global warming. We consider emissions reductions from better utilization of a given fleet of vehicles. We study an Economic Lot-Sizing setting in which a decision-maker determines the amount to be shipped in each period, and in which demand can fluctuate. Our paper assesses the trade-off between costs and carbon emissions. The emission parameters are based on a survey of results from empirical studies and on real-life considerations. In order to model the trade-off, we introduce a bi-objective lot-sizing model to find the Pareto optimal solutions with respect to costs and emissions. Our experiments show that it is often costly to reduce carbon emissions from the cost optimal solution, compared to carbon prices in the market. The cases in which carbon emissions can be reduced most cost-efficiently are those in which carbon emissions are large relative to costs, typically because costs are the results of past investments and can be considered sunk.
Event-Triggered State and Disturbance Estimation for Lipschitz Nonlinear Systems With Unknown Time-Varying Delays

We consider the event-triggered state and disturbance simultaneous estimation problem for Lipschitz nonlinear systems with an unknown time-varying delay in the state vector. For the first time, state and disturbance can be robustly estimated by using an event-triggered state observer. Our method uses only information of the output vector when an event-triggered condition is satisfied. This contrasts with previous methods of simultaneous state and disturbance estimation based on augmented state observers where the information of the output vector was assumed to be always continuously available. This salient feature, thus, lessens the stress on communication resources while can still maintain an acceptable estimation performance. First, to solve the new problem of event-triggered state and disturbance estimation, and to tackle unknown time-varying delays, we propose a novel event-triggered state observer and establish a sufficient condition for its existence. Then to overcome some technical difficulties in synthesizing observer parameters, we introduce some algebraic transformations and use inequalities, such as the Cauchy matrix inequality and the Schur complement lemma to establish a convex optimization problem in which observer parameters and optimal disturbance attenuation levels can be systematically derived. Finally, we demonstrate the applicability of the method by using two numerical examples.
1.3 µm range 40 GHz quantum-dot mode-locked laser under external continuous wave light injection or optical feedback

We have investigated the jitter, repetition frequency and spectra of a quantum-dot mode-locked laser operating at 40 GHz under continuous wave external light injection using an external cavity laser or under optical feedback. For the case of the continuous wave light injection we realized a shift of the optical emission of up to 15 nm. With optical feedback we have found a ninefold jitter reduction, down to a record low value of 1 ps over an integration range from 10 kHz to 1 GHz. Optical feedback fixes the repetition frequency while changing current and voltage applied to the diode. This is due to the fact that stable mode locking occurs at frequencies which are integers of the feedback loop frequency.
Determinants of perception of climate change and adaptation strategies of coffee-based agroforestry farmers in western Ethiopia

Background: A range of local social and environmental factors has an impact on farmers' views of climate change and choices on the use of coping mechanisms. This study examines the factors that are limiting farmers' perceptions of climate change and their coping mechanisms in Gimbi district, Western Ethiopia. Methods: A household survey and focus group discussion were employed to collect relevant data. A total of 402 randomly selected households and six focus group discussions containing 72 participants were used to gather data. Binary logit models were used to analyze the collected data. Results: Farmers noted that some of the signs of climate change included increasing temperature, erratic rainfall, late onset of rainfall, and early cessation of rainfall. We discovered that there are three distinct sets of climate adaption strategies used by farmers: crop management, soil and water conservation and intensive farm management. The primary determinants of farmers' perceptions of climate change and adaptation techniques were household head age, education, soil fertility, market access, and agricultural training. Age, education, and soil fertility level were the characteristics that significantly impacted farmers' perspectives and coping mechanisms among the primary drivers evaluated in the area. Use of Agroforestry, shifting planting dates, and fertilizer application were all essential farming practices used as climate adaptation measures. Conclusions: Both socioeconomic and environmental factors have found to affect farmers’ perceptions of climate change in the area. The existing socioeconomic and environmental factors, in turn, affect their choice of strategies to adapt to climate change. When implementing climate change adaption strategies, it is critical to assess farmers' level of awareness of climate change and their coping strategies, as well as the factors limiting their ability to adapt to climate change.
Stratospheric Aerosol Measurements II: The Worldwide Distribution

Abstract Global surveys of stratospheric and upper tropospheric aerosols have been made using balloon-borne photoelectric particle counters. The natural variability observed at each flight station was small enough so that typical profiles could be identified. Data are presented in the form of latitude cross sections showing lines of constant aerosol mixing ratio. The stratospheric aerosol layer is clearly delineated as well as small transient layers in the troposphere and lower stratosphere. At high and low latitudes the aerosol mixing ratio profile apparently experiences a simple shift in altitude corresponding to the change in local tropopause height.
Complete depletion in prestellar cores. Multiply-deuterated species in prestellar cores (Corrigendum)

In our papers, Walmsley et al. (2004) and Flower et al. (2004), the captions to the tables in the Appendices A were inexact with respect to the reactions involving grains. We stated (i) that the parameters α, β, and γ defined the rate coefficients k (cm3 s−1) at temperature T (K) through the relation k = J(ag, T )γ(T/300)αexp(−β/T ), where J allowed for Coulomb focusing in reactions of positive ions and negatively charged grains (Draine & Sutin 1987, Eq. (3.4)); and (ii) that a grain radius ag = 0.1 μm was adopted in the table. In fact, the tabulated values of γ were determined for a size distribution following the Mathis et al. (1977) power law, with limits 0.01 ≤ ag ≤ 0.3 μm. The tabulated value of γ was multiplied by (ag/0.02) within our program, to obtain the grain cross section corresponding to the adopted value of ag = 0.1 μm. (The mean radius for the size distribution of Mathis et al. (1977) is 0.02 μm. ) Thus, the tabulated values of γ for reactions between ions and grains should be increased by a factor of 25 to correspond to the numbers actually used in our models, for a grain size ag = 0.1 μm.
Constant free error bounds for nonuniform order discontinuous Galerkin finite-element approximation on locally refined meshes with hanging nodes

We obtain fully computable constant free a posteriori error bounds on the broken energy seminorm and the discontinuous Galerkin (DG) norm of the error for nonuniform polynomial order symmetric interior penalty Galerkin, nonsymmetric interior penalty Galerkin and incomplete interior penalty Galerkin finite-element approximations of a linear second-order elliptic problem on meshes containing hanging nodes and comprised of triangular elements. The estimators are completely free of unknown constants and provide guaranteed numerical bounds on the broken energy seminorm and the DG norm of the error. These estimators are also shown to provide a lower bound for the broken energy seminorm and the DG norm of the error up to a constant and higher-order data oscillation terms.
Enlargement of the Spleen Index Is a Predictor of the Occurrence of Esophageal Varices and Hepatocellular Carcinoma after Administering Direct-acting Antiviral Agents

Objective Direct-acting antiviral agents (DAAs) can eliminate hepatitis C virus at a high rate, although the long-term incidence of portal hypertension and hepatocellular carcinoma (HCC) has not yet been elucidated. In this observational study, we clarified the predictors associated with the incidence of esophageal varices (EVs) and HCC after DAAs treatment based on ultrasound findings and blood examinations. Methods A total of 78 patients treated with DAAs were enrolled in this study. The primary endpoint was to identify the predictors associated with EVs and HCC occurrence using univariate and multivariate analyses. Secondary endpoints were to extract the cutoff values for EVs and HCC occurrence and clarify the changes in liver stiffness (LS), spleen stiffness (SS), spleen index (SI), portal venous flow volume (PVF), and blood examination at 12 weeks after the end of DAAs treatment. Results The mean observation period was 1,402±546 days. SI change (SI after DAAs-SI before DAAs) was a predictor of EVs occurrence in multivariate analysis (p=0.045). The treatment history of HCC, albumin value before DAAs, and SI change were predictors of HCC occurrence in multivariate analysis (p=0.002, p=0.032, and p=0.009, respectively). LS, SS, PVF, SI, and liver function significantly improved after DAAs treatment. Conclusion Portal hypertension seems to improve after DAAs treatment over a long period. Patients with splenomegaly deterioration after DAAs treatment need to be carefully monitored for the occurrence of EVs and HCC.
The Problem of Three Stars: Stability Limit

Abstract The problem of three stars arises in many connections in stellar dynamics: three-body scattering drives the evolution of star clusters, and bound triple systems form long-lasting intermediate structures in them. Here we address the question of stability of triple stars. For a given system the stability is easy to determine by numerical orbit calculation. However, we often have only statistical knowledge of some of the parameters of the system. Then one needs a more general analytical formula. Here we start with the analytical calculation of the single encounter between a binary and a single star by Heggie (1975). Using some of the later developments we get a useful expression for the energy change per encounter as a function of the pericenter distance, masses, and relative inclination of the orbit. Then we assume that the orbital energy evolves by random walk in energy space until the accumulated energy change leads to instability. In this way we arrive at a stability limit in pericenter distance of the outer orbit for different mass combinations, outer orbit eccentricities and inclinations. The result is compared with numerical orbit calculations.
OPTIMAL CONVERGENCE RATES FOR THE COMPRESSIBLE NAVIER–STOKES EQUATIONS WITH POTENTIAL FORCES

For the viscous and heat-conductive fluids governed by the compressible Navier–Stokes equations with an external potential force, there exist non-trivial stationary solutions with zero velocity. By combining the Lp - Lq estimates for the linearized equations and an elaborate energy method, the convergence rates are obtained in various norms for the solution to the stationary profile in the whole space when the initial perturbation of the stationary solution and the potential force are small in some Sobolev norms. More precisely, the optimal convergence rates of the solution and its first order derivatives in L2-norm are obtained when the L1-norm of the perturbation is bounded.
THE RATIO OF MOLECULAR TO ATOMIC GAS IN SPIRAL GALAXIES AS A FUNCTION OF MORPHOLOGICAL TYPE

In order to gain an understanding of the global processes which influence cloud and star formation in disk galaxies, it is necessary to determine the relative amounts of atomic, molecular, and ionized gas both as a function of position in galaxies and from galaxy to galaxy. With observations of the CO distributions in over 200 galaxies now completed as part of the Five College Radio Astronomy Observatory (FCRAO) Extragalactic CO Survey (Young et al. 1989), researchers are finally in a position to determine the type dependence of the molecular content of spiral galaxies, along with the ratio of molecular to atomic gas as a function of type. Do late type spirals really have more gas than early types when the molecular gas content is included. Researchers conclude that there is more than an order of magnitude decrease in the ratio of molecular to atomic gas mass as a function of morphological type from Sa-Sd; an average Sa galaxy has more molecular than atomic gas, and an average Sc has less. Therefore, the total interstellar gas mass to blue luminosity ratio, M sub gas/L sub B, increases by less than a factor of two as a function of type from Sa-Sd. The dominant effect found is that the phase of the gas in the cool interstellar medium (ISM) varies along the Hubble sequence. Researchers suggest that the more massive and centrally concentrated galaxies are able to achieve a molecular-dominated ISM through the collection of more gas in the potential. That gas may then form molecular clouds when a critical density is exceeded. The picture which these observations support is one in which the conversion of atomic gas to molecular gas is a global process which depends on large scale dynamics (cf Wyse 1986). Among interacting and merging systems, researchers find considerable scatter in the M(H2)/M(HI) ratio, with the mean ratio similar to that in the early type galaxies. The high global ratio of molecular to atomic gas could result from the removal of HI gas, the enhanced conversion of HI into H2, or both.