Strong Restrictions Research Articles

Imperfect Substitutability in Real Estate Markets and the Effect of Housing Demand on the Macroeconomy

Changes in housing demand can have a macroeconomic effect through the collateral channel, where the change in residential real estate prices is associated with a change in commercial real estate prices, affecting firm collateral and thus firm investment. We argue that this channel is weaker when residential and commercial real estate are poor substitutes. Using cross-state heterogeneity in the strength of zoning regulations as a proxy for heterogeneity in the substitutability of residential and commercial real estate, we first show with firm level data that the strength of local zoning regulations has a negative effect on the estimated increase in firm investment following an increase in local residential real estate prices. We then construct a DSGE model where land has both residential and commercial uses and estimate it using Bayesian techniques and U.S. macroeconomic data. We find the average elasticity of substitution between commercial and residential real estate in the U.S. to be around 0.35, but in states with strong zoning restrictions it can be as low as 0.16 and in states with weak zoning restrictions it can be as high as 0.66. Simulations of the model show how these differences in zoning restrictions can affect the transmission of a housing demand shock to the macroeconomy.

Condition on the Rényi Entanglement Entropy under Stochastic Local Manipulation

The Rényi entanglement entropy (REE) is an entanglement quantifier considered as a natural generalization of the entanglement entropy. When it comes to stochastic local operations and classical communication (SLOCC), however, only a limited class of the REEs satisfy the monotonicity condition, while their statistical properties beyond mean values have not been fully investigated. Here, we establish a general condition that the probability distribution of the REE of any order obeys under SLOCC. The condition is obtained by introducing a family of entanglement monotones that contain the higher-order moments of the REEs. The contribution from the higher-order moments imposes a strict limitation on entanglement distillation via SLOCC. We find that the upper bound on success probabilities for entanglement distillation exponentially decreases as the amount of raised entanglement increases, which cannot be captured from the monotonicity of the REE. Based on the strong restriction on entanglement transformation under SLOCC, we design a new method to estimate entanglement in quantum many-body systems from experimentally observable quantities.

Solving hard stable matching problems involving groups of similar agents

Many important stable matching problems are known to be NP-hard, even when strong restrictions are placed on the input. In this paper we seek to identify structural properties of instances of stable matching problems which will allow us to design efficient algorithms using elementary techniques. We focus on the setting in which all agents involved in some matching problem can be partitioned into k different types, where the type of an agent determines his or her preferences, and agents have preferences over types (which may be refined by more detailed preferences within a single type). This situation would arise in practice if agents form preferences solely based on some small collection of agents' attributes. We also consider a generalisation in which each agent may consider some small collection of other agents to be exceptional, and rank these in a way that is not consistent with their types; this could happen in practice if agents have prior contact with a small number of candidates. We show that (for the case without exceptions), several well-studied NP-hard stable matching problems including Max SMTI (that of finding the maximum cardinality stable matching in an instance of stable marriage with ties and incomplete lists) belong to the parameterised complexity class FPT when parameterised by the number of different types of agents needed to describe the instance. For Max SMTI this tractability result can be extended to the setting in which each agent promotes at most one “exceptional” candidate to the top of his/her list (when preferences within types are not refined), but the problem remains NP-hard if preference lists can contain two or more exceptions and the exceptional candidates can be placed anywhere in the preference lists, even if the number of types is bounded by a constant.

Toward a large bandwidth photonic correlator for infrared heterodyne interferometry

Context. Infrared heterodyne interferometry has been proposed as a practical alternative for recombining a large number of telescopes over kilometric baselines in the mid-infrared. However, the current limited correlation capacities impose strong restrictions on the sensitivity of this appealing technique. Aims. In this paper, we propose to address the problem of transport and correlation of wide-bandwidth signals over kilometric distances by introducing photonic processing in infrared heterodyne interferometry. Methods. We describe the architecture of a photonic double-sideband correlator for two telescopes, along with the experimental demonstration of this concept on a proof-of-principle test bed. Results. We demonstrate the a posteriori correlation of two infrared signals previously generated on a two-telescope simulator in a double-sideband photonic correlator. A degradation of the signal-to-noise ratio of 13%, equivalent to a noise factor NF = 1.15, is obtained through the correlator, and the temporal coherence properties of our input signals are retrieved from these measurements. Conclusions. Our results demonstrate that photonic processing can be used to correlate heterodyne signals with a potentially large increase of detection bandwidth. These developments open the way to photonic processing of wide bandwidth signals for mid-infrared heterodyne interferometry, in particular for a large number of telescopes and for direct imager recombiners.

A helium mini-cryostat for the nanoprobe beamline ID16B at ESRF: characteristics and performance.

A helium mini-cryostat has been developed for the hard X-ray nanoprobe ID16B of the European Synchrotron to collect X-ray excited optical luminescence and X-ray fluorescence at low temperature (<10 K). The mini-cryostat has been specifically designed to fit within the strong space restrictions and high-demanding mechanical constraints imposed by the beamline to provide vibration-free operation and maximal thermal stability. This paper reports the detailed design, architecture and technical requirements of the mini-cryostat, and presents the first experimental data measured using the cryogenic equipment. The resulting cryo-system features ultimate thermal stability, fast cool-down and ultra-low vibrations. The simultaneous X-ray fluorescence and X-ray excited optical luminescence data acquired from bulk GaN and core/shell InGaN/GaN multi-quantum wells validated the excellent performance of the cryostat with ultimate resolution, stability and sensitivity.

Minimal ordered Ramsey graphs

An ordered graph is a graph equipped with a linear ordering of its vertex set. A pair of ordered graphs is Ramsey finite if it has only finitely many minimal ordered Ramsey graphs and Ramsey infinite otherwise. Here an ordered graph F is an ordered Ramsey graph of a pair (H,H′) of ordered graphs if for any coloring of the edges of F in colors red and blue there is either a copy of H with all edges colored red or a copy of H′ with all edges colored blue (where copies are not necessarily induced subgraphs). Such an ordered Ramsey graph is minimal if neither of its proper subgraphs is an ordered Ramsey graph of (H,H′). If H=H′ then H itself is called Ramsey finite.We show that a connected ordered graph is Ramsey finite if and only if it is a star with center being the first or the last vertex in the linear order. In general we prove that each Ramsey finite (not necessarily connected) ordered graph H has a pseudoforest as a Ramsey graph and therefore is a star forest with strong restrictions on the positions of the centers of the stars. In the asymmetric case we show that (H,H′) is Ramsey finite whenever H is a so-called monotone matching. Among several further results we show that there are Ramsey finite pairs of ordered stars and ordered caterpillars of arbitrary size and diameter. This is in contrast to the unordered setting where for any Ramsey finite pair (H,H′) of forests either one of H or H′ is a matching or both are star forests (with additional constraints).Several of our results give a relation between Ramsey finiteness and the existence of sparse ordered Ramsey graphs. Motivated by these relations we characterize all pairs of ordered graphs that have a forest as an ordered Ramsey graph and all pairs of ordered graphs that have a pseudoforest as a Ramsey graph.Our results show similarities between the ordered and the unordered setting for graphs containing cycles and significant differences for forests.

Shared Spaces in Cities of Poland

The aim of paper is a presentation an idea of shared space in the cities and results of implementation of this solution in the cities of Poland. The methodology of elaboration consisted of carrying out a review of the literature, comparing existing solutions and formulating conclusions regarding implementation. This trend, which has appeared over the past 50 years as a counterbalance to the pedestrianization of public spaces, is at the beginning of the 21st century experiencing its second youth and is being implemented in many areas in intensive urban development, especially in urban centers and areas of historic character. Shared space solutions are an integral way of shaping functions and forms of revitalized public spaces. These solutions contributes to improving the quality of public space and traffic safety, revitalizing social life, improving and reducing the environmental nuisance caused by traffic and finally created liveable city. Analyzes effectuated indicate, that in central areas of cities in Poland whose spatial arrangement is legally protected, the forms of shared spaces solutions are strongly influenced by strong conservation restrictions in these areas. This means the need to respect existing historical conditions in shaping public spaces, as well as limited transformation possibilities. The Polish solutions of shared spaces presented in this paper of in their forms and quality do not differ from the standard functional solutions abroad. Solutions implemented in the Polish conditions, however, are more modest in terms of materials and implemented in a smaller number than is the case in Western European countries.&#x0D; Keywords: Shared spaces, Traffic calming, Cities of Poland, Creation of public space

Restrictions for n-point vertices in higher-spin theories

We give a simple classification of the independent n-point interaction vertices for bosonic higher-spin gauge fields in d-dimensional Minkowski spacetimes. We first give a characterisation of such vertices for large dimensions, d ≥ 2n − 1, where one does not have to consider Schouten identities due to over-antisymmetrisation of spacetime indices. When the dimension is lowered, such identities have to be considered, but their appearance only leads to equivalences of large-d vertices and does not lead to new types of vertices. We consider the case of low dimensions (d < n) in detail, where a large number of Schouten identities leads to strong restrictions on independent vertices. We also comment on the generalisation of our results to the intermediate region n ≤ d ≤ 2n − 2. In all cases, the independent vertices are expressed in terms of elementary manifestly gauge-invariant quantities, suggesting that no deformations of the gauge transformations are induced.

Mean-variance efficiency of optimal power and logarithmic utility portfolios

We derive new results related to the portfolio choice problem for power and logarithmic utilities. Assuming that the portfolio returns follow an approximate log-normal distribution, the closed-form expressions of the optimal portfolio weights are obtained for both utility functions. Moreover, we prove that both optimal portfolios belong to the set of mean-variance feasible portfolios and establish necessary and sufficient conditions such that they are mean-variance efficient. Furthermore, we extend the derived theoretical finding to the general class of the log-skew-normal distributions. Finally, an application to the stock market is presented and the behaviour of the optimal portfolio is discussed for different values of the relative risk aversion coefficient. It turns out that the assumption of log-normality does not seem to be a strong restriction.

#toolittletoolate: JUUL-related content on Instagram before and after self-regulatory action.

IntroductionDigital e-cigarette marketing is largely unregulated and remains easily accessible to young people. The growing public concern around youth JUUL use and its viral presence on social media led the company to engage in several voluntary actions to remove and reduce JUUL-related content on Instagram in May 2018. The current study examined how JUUL-related Instagram content changed in the US following JUUL Labs’ wave of voluntary actions in May 2018.MethodsIn 2019, we collected a total of 50,817 JUUL-relevant posts by 16,323 unique users on Instagram from March 1-May 15, 2018 (Phase 1) and May 16-November 11, 2018 (Phase II) using the application programming interface. We conducted a semantic network analysis to identify major topic clusters over time.ResultsApproximately 14,838 JUUL-related posts were made by 5,201 accounts in Phase I and 35,979 posts were made by 11,122 accounts in Phase II. Major content clusters remained unchanged over time–key topics were JUUL-related product characteristics and JUUL-communities; the general vape community; and cannabis-related behavior. Of note, cannabis-related content grew in Phase II, particularly use of the term CBD.ConclusionsOur results reflect the limits of voluntary industry actions to reduce or change vaping-related content on social media. Rather, strong federal restriction on commercial tobacco marketing is the optimal pathway to reduce initial product marketing exposure among youth. These limits would make the emergence and viral contagion of brand-related social media content less likely and reduce its influence on youth behavior.

Shifts in monetary policy and exchange rate dynamics: Is Dornbusch's overshooting hypothesis intact, after all?

How do nominal exchange rates adjust after surprise contractions in monetary policy? While the seminal contribution by Dornbusch provides concise predictions—exchange rates appreciate, i.e., overshoot on impact before depreciating gradually—empirical support for his hypothesis is at best mixed. I argue that the failure to discover overshooting may result from assumptions researchers have imposed to recover structural VARs. Specifically, simultaneous feedback effects between interest rates and exchange rates, which are inherently forward-looking variables, are often excluded or modeled alongside with strong restrictions. In this paper, I identify U.S. monetary policy shocks using surprises in Federal funds futures around policy announcements as external instruments, which recent literature has established to represent the appropriate laboratory in settings encompassing macroeconomic and financial variables. Resulting adjustments of the dollar, conditional on shifts in policy, generally align with Dornbusch's predictions during the post-Bretton-Woods era, including Volcker's tenure as Fed Chair.

Cauchy problem for stochastic non-autonomous evolution equations governed by noncompact evolution families

This paper investigates the Cauchy problem to a class of stochastic non-autonomous evolution equations of parabolic type governed by noncompact evolution families in Hilbert spaces. Combining the theory of evolution families, the fixed point theorem with respect to convex-power condensing operator and a new estimation technique of the measure of noncompactness, we established some new existence results of mild solutions under the situation that the nonlinear function satisfy some appropriate local growth condition and a noncompactness measure condition. Our results generalize and improve some previous results on this topic, since the strong restriction on the constants in the condition of noncompactness measure is completely deleted, and also the condition of uniformly continuity of the nonlinearity is not required. At last, as samples of applications, we consider the Cauchy problem to a class of stochastic non-autonomous partial differential equation of parabolic type.

CP -violating dark photon interaction

We introduce a scenario for CP-violating (CPV) dark photon interactions in the context of non-abelian kinetic mixing. Assuming an effective field theory that extends the Standard Model (SM) field content with an additional $U(1)$ gauge boson ($X$) and a $SU(2)_L$ triplet scalar, we show that there exist both CP-conserving and CPV dimension five operators involving these new degrees of freedom and the SM $SU(2)_L$ gauge bosons. The former yields kinetic mixing between the $X$ and the neutral $SU(2)_L$ gauge boson (yielding the dark photon), while the latter induces CPV interactions of the dark photon with the SM particles. We discuss experimental probes of these interactions using searches for permanent electric dipole moments (EDMs) and di-jet correlations in high-energy $pp$ collisions. It is found that the experimental limit on the electron EDM currently gives the strongest restriction on the CPV interaction. In principle, high energy $pp$ collisions provide a complementary probe through azimuthal angular correlations of the two forward tagging jets in vector boson fusion. In practice, observation of the associated CPV asymmetry is likely to be challenging.

Optimization of Chance-Constrained Submodular Functions

Submodular optimization plays a key role in many real-world problems. In many real-world scenarios, it is also necessary to handle uncertainty, and potentially disruptive events that violate constraints in stochastic settings need to be avoided. In this paper, we investigate submodular optimization problems with chance constraints. We provide a first analysis on the approximation behavior of popular greedy algorithms for submodular problems with chance constraints. Our results show that these algorithms are highly effective when using surrogate functions that estimate constraint violations based on Chernoff bounds. Furthermore, we investigate the behavior of the algorithms on popular social network problems and show that high quality solutions can still be obtained even if there are strong restrictions imposed by the chance constraint.

Fuel cycle of light water reactor with full consumption of recycled uranium

Abstract The paper describes an approach to solve the problem of closing fuel cycle of light water reactors (LWR) trough the multiple uranium recycling. Since the second uranium recycle there is a problem of full return of the recycled uranium to LWR fuel cycle due to significant increasing of 232U concentration and strong regulatory restrictions on its content. The paper shows that the use of a double cascade is able to provide almost complete return of recycled uranium to the fuel cycle with minor losses. The reason for the losses is the necessity to clean the recycled uranium from the 232U isotope. We developed a multicriteria approach to choosing the optimal cascade scheme parameters. The efficiency of the algorithm is demonstrated by the example of enrichment of the recycled uranium of the second recycle. It is shown that not correctly selected optimization criteria of the double cascade enrichment scheme can lead to the fact that the loss of the 235U isotope, provided with waste treatment from 232U, will exceed its savings.

Smoothly embedding Seifert fibered spaces in 𝑆⁴

Using an obstruction based on Donaldson’s theorem, we derive strong restrictions on when a Seifert fibered space Y = F ( e ; p 1 q 1 , … , p k q k ) Y = F(e; \frac {p_1}{q_1}, \ldots , \frac {p_k}{q_k}) over an orientable base surface F F can smoothly embed in S 4 S^4 . This allows us to classify precisely when Y Y smoothly embeds provided e &gt; k / 2 e &gt; k/2 , where e e is the normalized central weight and k k is the number of singular fibers. Based on these results and an analysis of the Neumann-Siebenmann invariant μ ¯ \overline {\mu } , we make some conjectures concerning Seifert fibered spaces which embed in S 4 S^4 . Finally, we also provide some applications to doubly slice Montesinos links, including a classification of the smoothly doubly slice odd pretzel knots up to mutation.

Plataforma flexible para nodos sensores inalámbricos orientada a la medición de vibraciones en puentes

Las redes inalámbricas de sensores inteligentes tradicionales trabajan con datos escalares como temperatura o humedad, debido a que poseen fuertes restricciones de ancho de banda y consumo de energía. Sin embargo, en los últimos años, los avances tecnológicos han permitido un crecimiento significativo del uso de estas redes para procesamiento y transmisión de señales complejas como audio, video o vibraciones. En este trabajo se reporta el desarrollo de una plataforma flexible para nodos sensores capaces de medir, procesar, almacenar y transmitir inalámbricamente distintas variables físicas. El diseño de estos nodos permite su adaptación para el uso en aplicaciones que requieran mediciones y procesamiento de señales de complejidad diversa. Asimismo, los nodos permiten la transmisión inalámbrica de la información obtenida a partir del procesamiento local de las señales mencionadas. Finalmente, como caso de estudio se describe la adecuación de la plataforma para la medición de vibraciones en puentes carreteros.

MiniNet: An Efficient Semantic Segmentation ConvNet for Real-Time Robotic Applications

Efficient models for semantic segmentation, in terms of memory, speed, and computation, could boost many robotic applications with strong computational and temporal restrictions. This article presents a detailed analysis of different techniques for efficient semantic segmentation. Following this analysis, we have developed a novel architecture, MiniNet-v2, an enhanced version of MiniNet. MiniNet-v2 is built considering the best option depending on CPU or GPU availability. It reaches comparable accuracy to the state-of-the-art models but uses less memory and computational resources. We validate and analyze the details of our architecture through a comprehensive set of experiments on public benchmarks (Cityscapes, Camvid, and COCO-Text datasets), showing its benefits over relevant prior work. Our experiments include a sample application where these models can boost existing robotic applications.

Alcohol marketing policy and advertising exposure in low and middle income Latin American countries

While it is presumed that alcohol marketing policies decrease adolescent exposure to alcohol advertising, scientific literature on the topic is sparse. The current study sought to determine if alcohol marketing policy strength in the World Health Organization’s (WHO) region of the Americas was associated with adolescent alcohol ad exposure. A secondary analysis was conducted using data from the Global School-based Health Survey and the WHO’s Global Information System on Alcohol and Health . Linear regression was used, and the analysis included country-level (i.e. other alcohol policies, human development index (HDI), pattern of drinking score (PDS)) and individual-level (i.e. participant age, sex, socioeconomic status (SES), lifetime drinking status) covariates. Among 47,195 adolescents, 11–16 years old, from 13 countries, marketing policy strength was inversely associated with alcohol ad exposure (β (95% confidence interval (CI)) = −0.82 (−0.96, −0.68), p < .001). Other alcohol control measures, HDI, PDS, and participant SES were also inversely associated with exposure (p’s < .001). As presumed, alcohol marketing policies may reduce adolescent exposure to alcohol advertising, and countries should consider including strong marketing restrictions, or complete marketing bans, when implementing alcohol control policies in their effort to meet the sustainable development goals.

The Frenet-Serret description of Born rigidity and its application to the Dirac equation

The role played by non-inertial frames in physics is one of the most interesting subjects that we can study when dealing with a physical theory. It does not matter whether we are studying classical theories such as special relativity or quantum theory, the idea of an accelerated frame is always one of the first ideas to come to our minds. In the case of special relativity, a problem with the concept of rigidity emerged as soon as Max Born gave a reasonable definition of rigid motion: the Herglotz-Noether theorem imposes a strong restriction on the possible rigid motions. In this paper, the equivalence of this theorem with another one that is formulated with the help of Frenet-Serret formalism is proved, showing the connection between the rigid motion and the curvatures of the observer's trajectory in spacetime. In addition, the Dirac equation in the Frenet-Serret frame for an arbitrary observer is obtained and applied to the rotating observers. The solution in the rotating frame is given in terms of that of an inertial one.