Top Research Papers on Space

This work provides the first unambiguous evidence for a hippocampal representation of a conceptual space compared with a general feature-based space, by showing that the hippocampal distance signal selectively reflects the mapping of specifically conceptually relevant rather than of all feature dimensions.

Developer productivity is about more than an individual's activity levels or the efficiency of the engineering systems relied on to ship software, and it cannot be measured by a single metric or dimension. The SPACE framework captures different dimensions of productivity, and here we demonstrate how this framework can be used to understand productivity in practice and why using it will help teams better understand developer productivity and create better measures to inform their work and teams.

The shell bound by the Karman line at a height of ~80–100 km above the Earth’s surface and geosynchronous orbit at ~36,000 km is defined as the orbital space surrounding the Earth. It is within this region, and especially in low Earth orbit, where environmental issues are becoming urgent because of the rapid growth of the anthropogenic space object population, including satellite ‘mega-constellations’. In this Perspective, we summarize the case for considering the orbital space around the Earth as an additional ecosystem, subject to the same care and concerns, and the same broad regulations as...

This open access book provides a comprehensive view on data ecosystems and platform economics from methodical and technological foundations up to reports from practical implementations and applications in various industries.\nTo this end, the book is structured in four parts: Part I “Foundations and Contexts” provides a general overview about building, running, and governing data spaces and an introduction to the IDS and GAIA-X projects. Part II “Data Space Technologies” subsequently details various implementation aspects of IDS and GAIA-X, including eg data usage control, the usage of blockch...

Abstract The article investigates the control of the platform labour process by means of the digital production of space and how workers resist it. The segment of German platform‐mediated food delivery is examined via qualitative interviews and auto‐ethnography. It is shown how the platforms create different spaces to efficiently coordinate and control mobile delivery gig work. Steered by geolocalisation and geofencing, the couriers operate autonomously in spatial corridors defined by the platforms. The agency of the riders is thus limited, but they are occasionally able to undermine the platf...

Abstract The Galilean moons play major roles in the giant magnetosphere of Jupiter. At the same time, the magnetospheric particles and fields affect the moons. The impact of magnetospheric ions on the moons' atmospheres supplies clouds of escaping neutral atoms that populate a substantial fraction of their orbits. At the same time, ionization of atoms in the neutral cloud is the primary source of magnetospheric plasma. The stability of this feedback loop depends on the plasma/moon‐atmosphere interaction. The purpose of this review is to describe the physical processes that shape the space envi...

Space-time wave packets (STWPs) constitute a broad class of pulsed optical fields that are rigidly transported in linear media without diffraction or dispersion, and are therefore propagation-invariant in the absence of optical nonlinearities or waveguiding structures. Such wave packets exhibit unique characteristics, such as controllable group velocities in free space and exotic refractive phenomena. At the root of these behaviors is a fundamental feature underpinning STWPs: their spectra are not separable with respect to the spatial and temporal degrees of freedom. Indeed, the spatiotemporal...

This open access book presents the key aspects of statistics in Wasserstein spaces, i.e. statistics in the space of probability measures when endowed with the geometry of optimal transportation. Further to reviewing state-of-the-art aspects, it also provides an accessible introduction to the fundamentals of this current topic, as well as an overview that will serve as an invitation and catalyst for further research. Statistics in Wasserstein spaces represents an emerging topic in mathematical statistics, situated at the interface between functional data analysis (where the data are functions, ...

The past decade has experienced an increase in the number of studies on organizational space or where work occurs. A number of these studies challenge traditional views of organizational space as a fixed, physical workspace because researchers fail to account for the spatial dynamics that they observe. New technologies, shifting employee-employer relations, and burgeoning expectations of the contemporary workforce blur boundaries between home and work, connect people and things that historically could not be linked, and extend workspaces to nearly everywhere, not just office buildings. Researc...

A bstract We consider black holes in 2d de Sitter JT gravity coupled to a CFT, and entangled with matter in a disjoint non-gravitating universe. Tracing out the entangling matter leaves the CFT in a density matrix whose stress tensor backreacts on the de Sitter geometry, lengthening the wormhole behind the black hole horizon. Naively, the entropy of the entangling matter increases without bound as the strength of the entanglement increases, but the monogamy property predicts that this growth must level off. We compute the entropy via the replica trick, including wormholes between the replica c...

The key technologies of ISA are analyzed from three aspects: assembly structure design, robot technologies and integrated management technologies, which show that ISA will play a vital role in human space exploration in the future.

This textbook deals with the requirements of space physics. The first part starts with a description of the Earth's plasma environment, followed by a derivation of single particle motions in electromagnetic fields, with applications to the Earth's magnetosphere. Then the origin and effects of collisions and conductivities, formation of the ionosphere, magnetospheric convection and dynamics, and solar wind-magnetosphere coupling are discussed.The second part of the book presents a more theoretical foundation of plasma physics, starting from kinetic theory. Introducing moments of the distributio...

Conventional π-conjugated luminophores suffer from problems such as emission quenching, biotoxicity, environmental pollution, etc. The emerging nonconjugated and nonaromatic clusteroluminogens (CLgens) are expected to overcome these stubborn drawbacks, so research of CLgens shows great significance not only for practical application but also for the construction of fundamental photophysical theories. This perspective summarizes the unusual features of CLgens in comparison to traditional chromophores, such as nonconjugated molecular structures, unmatched absorption and excitation, excitation-de...

Recent theoretical and methodological advances in urban sociology, including spatially located data, provide new opportunities to consider the joint influence of mobility and place in urban social life. This review defines the concept of activity space, describes its origins in urban sociology, and examines the extent to which activity space approaches advance sociological research in four substantive domains—spatial inequality and segregation, social connectedness and engagement, crime and offending patterns, and health and health-related behavior. It next describes the evolution of methods f...

Public Places Urban Spaces provides a comprehensive overview of the principles, theory and practices of urban design for those new to the subject and for those requiring a clear and systematic guide. In this new edition the book has been extensively revised and restructured. Carmona advances the idea of urban design as a continuous process of shaping places, fashioned in turn by shifting global, local and power contexts. At the heart of the book are eight key dimensions of urban design theory and practice—temporal, perceptual, morphological, visual, social, functional—and two new process dimen...

A bstract The covariant phase space method of Iyer, Lee, Wald, and Zoupas gives an elegant way to understand the Hamiltonian dynamics of Lagrangian field theories without breaking covariance. The original literature however does not systematically treat total derivatives and boundary terms, which has led to some confusion about how exactly to apply the formalism in the presence of boundaries. In particular the original construction of the canonical Hamiltonian relies on the assumed existence of a certain boundary quantity “ B ”, whose physical interpretation has not been clear. We here give an...

A model of the cascade of events occurring during neuroinflammatory pathology is proposed and described, to advance the comprehension of the pathophysiology of neuroinflammation and open a new therapeutic window for neuroinflammatory diseases such as multiple sclerosis.

People feel lonely when their social needs are not met by the quantity and quality of their social relationships. Most research has focused on individual-level predictors of loneliness. However, macro-level factors related to historical time and geographic space might influence loneliness through their effects on individual-level predictors. In this Review, we summarize empirical findings on differences in the prevalence of loneliness across historical time and geographical space and discuss four groups of macro-level factors that might account for these differences: values and norms, family a...

This review provides an overview of some algorithmic approaches to defining and exploring chemical spaces that have the potential to operationalize the process of molecular discovery and emphasizes the potential roles of machine learning and the consideration of synthetic feasibility, which is a prerequisite to ‘closing the loop’.

There is an urgent demand to introduce a concept, that is, confined space, which is capable of precisely monitoring the process of elec-tron/charge transfer by a designable and controllable sensing interface whose size is comparable with that of single entities.

The Relational Dynamics of Space-Time is a groundbreaking theory that redefines space-time as an emergent and discrete structure, arising from fundamental interactions between elementary entities. Rooted in the principle that “nothing is empty, nothing is solitary; interactions define reality”, this theory challenges the notion of a pre-existing, continuous space-time and introduces a relational framework for its origin and dynamics. The model organizes these interactions into three fundamental levels: Binary interactions, responsible for local equilibrium and structural stability. Triple inte...

Quantum theory has been successfully validated in numerous laboratory\nexperiments. But would such a theory, which excellently describes the behavior\nof microscopic physical systems, and its predicted phenomena such as quantum\nentanglement, be still applicable on very large length scales? From a practical\nperspective, how can quantum key distribution -- where the security of\nestablishing secret keys between distant parties is ensured by the laws of\nquantum mechanics -- be made technologically useful on a global scale? Due to\nphoton loss in optical fibers and terrestrial free space, the a...

It is shown how path integrals can be differentiated with respect to arbitrary differentiable changes of a scene and the design of new Monte Carlo estimators that offer significantly better efficiency than state-of-the-art methods in handling complex geometric discontinuities and light transport phenomena such as caustics are considered.

The covariant phase space method of Iyer, Lee, Wald, and Zoupas gives an elegant way to understand the Hamiltonian dynamics of Lagrangian field theories without breaking covariance. The original literature however does not systematically treat total derivatives and boundary terms, which has led to some confusion about how exactly to apply the formalism in the presence of boundaries. In particular the original construction of the canonical Hamiltonian relies on the assumed existence of a certain boundary quantity “B”, whose physical interpretation has not been clear. We here give an algorithmic...

We consider black holes in 2d de Sitter JT gravity coupled to a CFT, and entangled with matter in a disjoint non-gravitating universe. Tracing out the entangling matter leaves the CFT in a density matrix whose stress tensor backreacts on the de Sitter geometry, lengthening the wormhole behind the black hole horizon. Naively, the entropy of the entangling matter increases without bound as the strength of the entanglement increases, but the monogamy property predicts that this growth must level off. We compute the entropy via the replica trick, including wormholes between the replica copies of t...

Five classes of synthetic light-switchable compounds are discussed—diarylethenes, anthracenes, azobenzenes, spiropyrans, and donor–acceptor Stenhouse adducts—comparing their behaviors under confinement and in solution, and it is found that photoswitches requiring less conformational freedom for switching are, as expected, more straightforward to isomerize reversibly under confinement.

A digital hardware platform is developed and the space multistructure attractors as well as the space coexisting attractors are experimentally demonstrated and a pseudorandom number generator is designed to explore the potential application of the proposed TM-HNN.

The novel results from this study will allow decision-makers better design UGS and directly pinpoint relevant quality dimensions to promote physical activity, reduce the risk of overweight/obesity and boost the use of UGS amongst citizens.

Urban green spaces (UGS) offer a wide range of ecosystem services to city dwellers, contributing to their health and well-being. The resources of formally designated UGS, such as parks and forests, are frequently underprovided, however. This results in unequal access to UGS, which has become an environmental justice issue. We investigated the potential of informal green spaces (IGS) to complement existing formal UGS to reduce distributional inequity in UGS availability. We focused on the most vulnerable groups of citizens, children and elderly residents, for whom the availability of UGS plays ...

This paper applies existing directional similarity measures to identify hypernyms with a state-of-the-art distributional semantic model and proposes a new directional measure that achieves the best performance in hypernym identification.

More precise explanations are needed to better understand why public green spaces are diminishing in cities, leading to the loss of ecosystem services that humans receive from natural systems. This paper is devoted to the incremental change of green spaces—a fate that is largely undetectable by urban residents. The paper elucidates a set of drivers resulting in the subtle loss of urban green spaces and elaborates on the consequences of this for resilience planning of ecosystem services. Incremental changes of greenspace trigger baseline shifts, where each generation of humans tends to take the...

A bstract Recent developments involving JT gravity in two dimensions indicate that under some conditions, a gravitational path integral is dual to an average over an ensemble of boundary theories, rather than to a specific boundary theory. For an example in one dimension more, one would like to compare a random ensemble of two-dimensional CFT’s to Einstein gravity in three dimensions. But this is difficult. For a simpler problem, here we average over Narain’s family of two-dimensional CFT’s obtained by toroidal compactification. These theories are believed to be the most general ones with thei...

This paper presents a comprehensive cross-country database of fiscal space, broadly defined as the availability of budgetary resources for a government to service its financial obligations. The database covers up to 202 countries over the period 1990–2020, and includes 30 indicators of fiscal space grouped into four categories: debt sustainability, balance sheet vulnerability, external and private sector debt-related risks as potential causes of contingent liabilities, and market access. Using the database, the paper, first, documents the weakening of fiscal space in the 1990s, the broad-based...

A bstract We describe an algebra of observables for a static patch in de Sitter space, with operators gravitationally dressed to the worldline of an observer. The algebra is a von Neumann algebra of Type II 1 . There is a natural notion of entropy for a state of such an algebra. There is a maximum entropy state, which corresponds to empty de Sitter space, and the entropy of any semiclassical state of the Type II 1 algebras agrees, up to an additive constant independent of the state, with the expected generalized entropy S gen = ( A/ 4 G N ) + S out . An arbitrary additive constant is present b...

Acknowledgments Introduction 1. Nature and Nurture as Alternatives 2. Changing the Question to One that Does Make Sense-From Trait to Trait Difference 3. From Individuals to Populations 4. What's to Be Done? Notes Bibliography Index

The rapid increase in world population in the 21st century, with associated transport and environmental problems, has encouraged the development of urban underground spaces as an optimal solution in many occasions, including urban renewal schemes. This paper reviews literature on the utilisation of urban underground space for urban renewal to provide a better understanding of how urban underground space can contribute to urban renewal, and of challenges and successes in achieving the goals. The paper concludes that urban underground space present new development opportunities (e.g. land/space ...

This paper adapts Mamba, a state-space language model, into VMamba, a vision backbone with linear time complexity, which develops a family of VMamba architectures and accelerate them through a succession of architectural and implementation enhancements.

A bstract We develop a Mellin space approach to boundary correlation functions in anti-de Sitter (AdS) and de Sitter (dS) spaces. Using the Mellin-Barnes representation of correlators in Fourier space, we show that the analytic continuation between AdS d +1 and dS d +1 is encoded in a collection of simple relative phases. This allows us to determine the late-time tree-level three-point correlators of spinning fields in dS d +1 from known results for Witten diagrams in AdS d +1 by multiplication with a simple trigonometric factor. At four point level, we show that Conformal symmetry fixes excha...

This work will address the recent development of data‐driven technologies for chemical reaction tasks, including forward reaction prediction, retrosynthesis, reaction optimization, catalysts design, inference of experimental procedures, and reaction classification.

Spacematrix explores the potential of urban density as a tool for urban planning and design. This revised and extended edition of Meta Berghauser Pont and Per Haupt’s 2010 volume includes an extensive analysis of the relations between density, urban form and performance – a prerequisite for understanding and successfully predicting the effects of specific designs and planning proposals. The density database that is an integral part of the book has been expanded and now includes 142 examples from five capitals in Europe as well as examples from Asia. Berghauser Pont and Haupt demystify the use ...