Stony Brook University

About: Stony Brook University is a education organization based out in Stony Brook, New York, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 32534 authors who have published 68218 publications receiving 3035131 citations. The organization is also known as: State University of New York at Stony Brook & SUNY Stony Brook.

Indoor Tracking: Theory, Methods, and Technologies

Abstract: In the last decade, the research on and the technology for outdoor tracking have seen an explosion of advances. It is expected that in the near future, we will witness similar trends for indoor scenarios where people spend more than 70% of their lives. The rationale for this is that there is a need for reliable and high-definition real-time tracking systems that have the ability to operate in indoor environments, thus complementing those based on satellite technologies, such as the Global Positioning System (GPS). The indoor environments are very challenging, and as a result, a large variety of technologies have been proposed for coping with them, but no legacy solution has emerged. This paper presents a survey on indoor wireless tracking of mobile nodes from a signal processing perspective. It can be argued that the indoor tracking problem is more challenging than the problem on indoor localization. The reason is simple: From a set of measurements, one has to estimate not one location but a series of correlated locations of a mobile node. The paper illustrates the theory, the main tools, and the most promising technologies for indoor tracking. New directions of research are also discussed.

Water on an Urban Planet: Urbanization and the Reach of Urban Water Infrastructure

Abstract: A B S T R A C T Urban growth is increasing the demand for freshwater resources, yet surprisingly the water sources of the world’s large cities have never been globally assessed, hampering efforts to assess the distribution and causes of urban water stress. We conducted the first global survey of the large cities’ water sources, and show that previous global hydrologic models that ignored urban water infrastructure significantly overestimated urban water stress. Large cities obtain 78 � 3% of their water from surface sources, some of which are far away: cumulatively, large cities moved 504 billion liters a day (184 km 3 yr � 1 ) a distance of 27,000 � 3800 km, and the upstream contributing area of urban water sources is 41% of the global land surface. Despite this infrastructure, one in four cities, containing $4.8 � 0.7 trillion in economic activity, remain water stressed due to geographical and financial limitations. The strategic management of these cities’ water sources is therefore important for the future of the global economy.

Archaeological Evidence for the Emergence of Language, Symbolism, and Music–An Alternative Multidisciplinary Perspective

Abstract: In recent years, there has been a tendency to correlate the origin of modern culture and language with that of anatomically modern humans. Here we discuss this correlation in the light of results provided by our first hand analysis of ancient and recently discovered relevant archaeological and paleontological material from Africa and Europe. We focus in particular on the evolutionary significance of lithic and bone technology, the emergence of symbolism, Neandertal behavioral patterns, the identification of early mortuary practices, the anatomical evidence for the acquisition of language, the development of conscious symbolic storage, the emergence of musical traditions, and the archaeological evidence for the diversification of languages during the Upper Paleolithic. This critical reappraisal contradicts the hypothesis of a symbolic revolution coinciding with the arrival of anatomically modern humans in Europe some 40,000 years ago, but also highlights inconsistencies in the anatomically–culturally modern equation and the potential contribution of anatomically “pre-modern” human populations to the emergence of these abilities. No firm evidence of conscious symbolic storage and musical traditions are found before the Upper Paleolithic. However, the oldest known European objects that testify to these practices already show a high degree of complexity and geographic variability suggestive of possible earlier, and still unrecorded, phases of development.

Geometry of the complex of curves ii: hierarchical structure

Abstract: This paper continues a geometric study of Harvey's Complex of Curves, whose ultimate goal is to apply the theory of hyperbolic spaces and groups to algorithmic questions for the Mapping Class Group and geometric properties of Kleinian representations. The authors' previous result that the complex is delta-hyperbolic was hard to apply because the complex is not locally finite; in this paper some tools are developed for overcoming this problem, and a combinatorial mechanism introduced which describes sequences of elementary moves in the graph of markings on a surface. These tools are applied to give a family of quasi-geodesic words in the Mapping Class Group, and a linear bound on the shortest word conjugating two conjugate pseudo-Anosov elements. A basic tool in the analysis is a family of subsurface projections, which are roughly analogous to closest-point projections to horoballs in classical hyperbolic space. These projections have a strong contraction property which makes it possible to tie together the geometry of the complex and that of the (infinite) subcomplexes that arise as links of vertices. The resulting layered structure of the complex is controlled by means of a combinatorial device called a hierarchy of geodesics, which is the central construction of the paper.

Conversion Reaction Mechanisms in Lithium Ion Batteries: Study of the Binary Metal Fluoride Electrodes

Abstract: Materials that undergo a conversion reaction with lithium (e.g., metal fluorides MF2: M = Fe, Cu, ...) often accommodate more than one Li atom per transition-metal cation, and are promising candidates for high-capacity cathodes for lithium ion batteries. However, little is known about the mechanisms involved in the conversion process, the origins of the large polarization during electrochemical cycling, and why some materials are reversible (e.g., FeF2) while others are not (e.g., CuF2). In this study, we investigated the conversion reaction of binary metal fluorides, FeF2 and CuF2, using a series of local and bulk probes to better understand the mechanisms underlying their contrasting electrochemical behavior. X-ray pair-distribution-function and magnetization measurements were used to determine changes in short-range ordering, particle size and microstructure, while high-resolution transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) were used to measure the atomic-level s...