In multi-robot collision avoidance navigation problems, it is common to encounter situations where robots get stuck and cannot avoid collisions or complete navigation tasks, known as deadlock problems. There are various reasons for the occurrence of deadlock problems, such as issues with the navigation method itself. Optimal reciprocal collision avoidance (ORCA) is widely used in multi-robot navigation. However, in some scenes, such as where robots distribute symmetrically, ORCA usually fails to plan reasonable collision avoidance velocities, resulting in the robot getting stuck. In this paper, we aim to address the deadlock problem caused by ORCA. We first analyze and simplify the planning process of ORCA from the principal horizon to break the deadlock situation. Then, deep reinforcement learning is used to optimize the escape velocity and collision avoidance responsibility of ORCA to guarantee collision-free navigation. We compare our method with the original ORCA and other learning-based methods. The results show that the proposed method is beneficial in reducing the deadlock probability and the collision probability in multi-robot navigation.

This article analyzes variation in and metalinguistic commentary surrounding the primary stressed vowel of the place-name ‘Chicago’. Sociolinguistic interview data with fifty-six lifelong Chicagoans from two adjacent neighborhoods reveal both social variation and apparent time evolution in the phonetic manifestation and phonemic patterning of the CHICAGO vowel. Contrastive metalinguistic ideologies substantiate this variation, as different speakers map ‘authentic’ versus ‘inauthentic’ Chicagoness to opposite phonemic variants. While previous work on place-names proposed linkages between place identity and linguistic material that can articulate stances toward geographic areas, we document inverted semiotic mappings among residents who otherwise share the same positive orientation to their neighborhood. We draw upon locally constructed chronotopes to account for the inverse polarization characterizing the CHICAGO vowel. We ultimately argue for dynamic conceptions of place-based linguistic features that attend more closely to the ideologically productive nature of local identity. (Authenticity, place, race, sociolinguistic variation, differentiation, chronotope)

We compute the rate of exponential growth of the free inverse monoid of rank r (and hence an upper bound on the corresponding rate for all r-generated inverse monoids and semigroups). This turns out to be an algebraic number strictly between the obvious bounds of $2r-1$ and $2r$, tending to $2r$ as the rank tends to infinity. We also find an explicit expression for the exponential growth rate of the number of idempotents, and prove that this tends to $\sqrt {e(2r-1)}$ as $r \to \infty $.

We explore how information from covariates can be incorporated into the CUSUM-based real-time monitoring procedure for explosive asset price bubbles developed in Homm and Breitung (2012, Journal of Financial Econometrics 10, 198–231). Where dynamic covariates are present in the data generating process (DGP), the false positive rate (FPR) of the basic CUSUM procedure, which is based on the assumption that prices follow a univariate DGP, under the null of no explosivity will not, in general, be properly controlled, even asymptotically. In contrast, accounting for these relevant covariates in the construction of the CUSUM statistics leads to a procedure whose FPR can be controlled using the same asymptotic crossing function as employed by Homm and Breitung (2012). Doing so is also shown to have the potential to significantly increase the chance of detecting an emerging bubble episode in finite samples. We additionally allow for time-varying volatility in the innovations driving the model through the use of a kernel-based variance estimator.

Egalitarianism and prioritarianism are competing views about the ethics of distribution. Both views have wide scopes of concern. But, writing in this journal, Michael Otsuka has discovered a case that seems to show an interesting asymmetry between the limits of egalitarian and prioritarian concern. In that case, intuitively one outcome is better than another (in a respect relevant to the ethics of distribution); prioritarianism can recover that intuitive judgment; but egalitarianism seems unable to recover it. I show, however, that egalitarianism can recover the intuitive judgment in question on a well-motivated basis. That result is of interest because it shows the possibility and prima facie plausibility of a version of egalitarianism with a surprisingly wide scope of concern – one according to which it matters that some are worse off than those who (merely) could have existed.

This study explores the intricate design of title pages in nineteenth-century Persian lithographed books, comparing the Eastern-style title pages prevalent in Indian publications with the Western-influenced designs found in Iranian lithographed books. Rooted in Indian publishing traditions, the Eastern model emphasised structured bibliographic details, refined calligraphy, and floral ornamentation. In contrast, the Western-style Iranian model drew inspiration from Persian manuscript and bookbinding traditions, a broader ornamental vocabulary shared across media, particularly the lachak va turanj (medallion-and-corner) compositional scheme. While Iranian designers rarely adopted the Eastern model in books published in Iran, Indian publications occasionally incorporated Persian design elements, demonstrating selective cross-regional exchanges in Persianate book design. Rather than developing a standardised informational layout, Iranian title pages prioritised visual composition and ornamental hierarchy, often relegating bibliographic information to colophons or extended dedicatory texts. Accordingly, the Western style is defined less by informational structure than by visual organisation, which distinguishes it fundamentally from the Eastern model. This study focuses on Iranian and Indian examples, drawing on rare Persian lithographed books to examine how differing conceptions of the book shaped title page design in the nineteenth century.

In July of 2024, signatures for placing an anti-gerrymandering initiative on the November ballot were certified by the Ohio Secretary of State. The proposed initiative would have replaced a bipartisan redistricting commission with a citizens’ redistricting commission. Though the initiative ultimately failed, polls leading up to the general election showed Ohioans strongly supported redistricting reform. Using a survey of likely voters in Ohio, the research presented here identifies the factors that explain support for redistricting reform. While there is a strong body of research on redistricting, this research is unique because the survey data come from likely voters during an actual redistricting campaign. The findings show that identifying threats to democracy as the most important election issue, awareness of the redistricting issue, identification with the Democratic Party, and liberal ideology are all positively associated with support for redistricting reform. The findings demonstrate how voters are influenced by partisanship on salient issues and how issue awareness interacts with partisanship to determine support for redistricting. This article concludes with a discussion of the context of the ballot initiative in Ohio.

Cet article se propose de revenir sur la question de la reproduction sociale au sein des institutions universitaires françaises au début du xxe siècle à partir de l’exemple du célèbre historien Marc Bloch (1886-1944), normalien dont le père, Gustave Bloch (1848-1923), fut lui-même non seulement normalien mais également professeur à l’École normale supérieure. La question se pose en des termes spécifiques en un temps où l’ENS perdit son autonomie pour devenir un institut pédagogique intégré à l’université de Paris : Marc Bloch fut donc à la fois un pur produit de l’ENS et de l’Université et il eut toujours à cœur de nourrir sa pratique professionnelle avec cette double culture. En s’appuyant sur les nombreuses archives que sa formation à l’ENS a laissées, il est possible de comprendre comment se déroulait la formation d’un historien à l’ENS à l’époque de Marc Bloch, comment la personnalité de ce dernier s’y est peu à peu affirmée en s’appuyant sur certaines dispositions propres à un héritier intellectuel, et d’observer de quelle manière cet héritage normalien a pu être plus ou moins activé pendant l’ensemble de son parcours d’historien et de citoyen.

In this article we introduce a gluing operation on dimer models. This allows us to construct dimer quivers on arbitrary surfaces. We study how the associated dimer and boundary algebras behave under the gluing and how to determine them from the gluing components. We also use this operation to construct homogeneous dimer quivers on annuli.

This article examines the hybrid network structure of the global sustainability governance system, focusing on the evolving relationships between private transnational regulators (PTRs) and intergovernmental organizations (IOs). We argue that a defining feature of this structure is the mutual dependence between PTRs and IOs: PTRs invoke public international law instruments (PILIs) – and, by extension, the authority of the IOs behind them – to bolster their own authority and to enhance the normative force of the standards they promulgate. IOs rely on PTRs to disseminate their norms within corporate settings, thereby strengthening their compliance capacities. This interdependence carries significant synergistic potential. We examine the grounding relationship between PTRs and PILIs/IOs through extensive network analysis based on a specially curated dataset comprising 55 PTRs, 393 private standards, 261 PILIs (including treaties, conventions, and declarations), and 41 IOs. Citation patterns within this network support our thesis. We also offer tentative evidence regarding the second prong of our model and outline directions for future research. Finally, we assess the vulnerabilities of this interdependent structure, highlighting the fragility of the global sustainability legal order in the face of rising nationalism and anti-multilateralist pressures.

In Denver area census tracts during the years 2016–2019, the rate of carbapenem-resistant enterobacterales (CRE) infection increased by 10% for every 0.1 unit increase in Social Vulnerability Index (RR 1.10, 95% CI 1.06, 1.14). This finding suggests that community factors may influence risk of healthcare-associated infections such as CRE.