7,502 research outputs found
Global mapping of iron and titanium oxides in the lunar megaregolith and subsurface
[Abstract]:
This paper reports mapping results obtained by remote sensing analysis of Iron and Titanium oxides in the megaregolith under the lunar Highlands regolith and in the subsurface under the Mare and South Pole Aitken basin regolith. FeO and TiO2 images were mosaicked from data extracted from the 1994 Clementine lunar orbiter mission from 600 N to 600 S, using the Lucey et al. technique (2000). These images then used to study the ejecta blanket for each of 2059 craters analysed using ISIS software (US Geological Survey). Average weight percentage values for each crater ejecta blanket were interpolated to derive underlying global Province Maps for FeO and TiO2. The Moon was divided into five (5) provinces as a balance of the needs of analysis requirements and simplicity. Division of global TiO2 weight percentages in the megaregolith /subsurface five provinces was matching the observed distribution of that at the surface. In contrast, division of lunar FeO into 5 Provinces reveals unexpectedly elevated iron concentrations (3.8 to 6.4%) in some areas of the Highland megaregolith. This Province of elevated iron oxide is termed “Highland II”
Multiple path prediction for traffic scenes using LSTMs and mixture density models
This work presents an analysis of predicting multiple future paths of moving objects in traffic scenes by leveraging Long Short-Term Memory architectures (LSTMs) and Mixture Density Networks (MDNs) in a single-shot manner. Path prediction allows estimating the future positions of objects. This is useful in important applications such as security monitoring systems, Autonomous Driver Assistance Systems and assistive technologies. Normal approaches use observed positions (tracklets) of objects in video frames to predict their future paths as a sequence of position values. This can be treated as a time series. LSTMs have achieved good performance when dealing with time series. However, LSTMs have the limitation of only predicting a single path per tracklet. Path prediction is not a deterministic task and requires predicting with a level of uncertainty. Predicting multiple paths instead of a single one is therefore a more realistic manner of approaching this task. In this work, predicting a set of future paths with associated uncertainty was archived by combining LSTMs and MDNs. The evaluation was made on the KITTI and the CityFlow datasets on three type of objects, four prediction horizons and two different points of view (image coordinates and birds-eye vie
Beyond Ohba's Conjecture: A bound on the choice number of -chromatic graphs with vertices
Let denote the choice number of a graph (also called "list
chromatic number" or "choosability" of ). Noel, Reed, and Wu proved the
conjecture of Ohba that when . We
extend this to a general upper bound: . Our result is sharp for
using Ohba's examples, and it improves the best-known
upper bound for .Comment: 14 page
The Time of Beauty
For Levinson, the Keats who thus suffers is our angel of history as described by Benjamin - face turned to the past, blown irresistibly into the future - and, in the later work especially, he reappears as the avenging angel who turns the instruments of domination against the culture that wields them.5 A postulate common in the boom years of the new historicism, best captured by Fredric Jameson's famous remark that "History is what hurts," maintained that the force of "history" is chiefly made manifest in forms of affective "hurt," trauma, and so forth.6 Where this is the case, the beautiful may signify no more than as the possibility of momentary consolation or the utopianism of a perpetually deferred redemption of time. Whether this work takes its cue from Newell Ford's description of Keatsian beauty as "prefigurati ve truth," Paul de Man's characterization of Keats's imagination as largely "prospective" in its orientation, or Patricia Parker's account of the "perpetual 'à venir in Keats," it is the forward-looking poet whose voice has most often been claimed for politics.7 Hazlitt's Essay on the Principles of Human Action furnishes a guidebook for the ethical dimensions of this self-divesting orientation towards futurity; the negatively capable chameleon poet is hailed as its literary embodiment
Mary A. Favret, War at a Distance: Romanticism and the Making of Modern Wartime: a Review
Mary Favret’s War at a Distance: Romanticism and the Making of Modern Wartime is a brilliant, beautifully written book on the experience of war in British Romantic writing. Offering intricate close readings of Cowper, Wordsworth, Austen, Coleridge, and others, Favret situates these canonical writers in relation to large historical contexts: writings in a prophetic mode by Robert Brothers and Captain Charles W. Pasley, 18th century weather history, and British paintings of colonial India, to name a few. Beyond the texts and images of the Romantic period. War at a Distance moves with impressive sweep between wartimes past and present, from the Revolution and Napoleonic conflicts of two centuries ago to the first and second Gulf Wars of the 20th and 21st centuries. War at a Distance is a stirring and powerful meditation on what it means to live in a time of war
The unbearable lightness of tourism … as violence: an afterword
This Afterword reviews the special issue of the Journal of Sustainable
Tourism on Critical Geographies, which focuses on the intricate
relationships between tourism and various forms of tourism related
violence. It notes the slippery and complex concept of violence in tourism,
and that it is typically seen from the viewpoint of the tourist, with
researchers working from the anthropological host and guests
relationship model as a way of negotiating kinship and friendship
between societies, with broader aspects of tourism's power play with
socio-cultural change perhaps conveniently forgotten. Tourism and
tourists are seen as hiding their corporate and personal violence behind
destination branding, tourism imaginaries and saleable commodification.
While the innovative approaches adopted by papers in the special issue
are commended, two key and still outstanding issues are highlighted.
Tourism researchers must find ways to share their work more effectively
across all stakeholders, as well as publishing in academic journals. And
researchers should become more self reflexive and critical of themselves,
seeking to address the complex practical challenges for sustainable
tourism thinkers and doers of creating better links between the visitors
and businesses of developed societies, and the culture and communities
of developing societies
WLAN CSMA/CA Performance in a Bluetooth Interference Environment
IEEE 802.11 WLANs and Bluetooth piconets both operate in the 2.4 GHz Industrial Scientific and Medical (ISM) radio band. When operating in close proximity, these two technologies interfere with each other. Current literature suggests that IEEE 802.11 (employing direct sequence spread spectrum technology) is more susceptible to this interference than Bluetooth, which uses frequency hopping spread spectrum technology, resulting in reduced throughput. Current research tends to focus on the issue of packet collisions, and not the fact that IEEE 802.11 may also delay its transmissions while the radio channel is occupied by a Bluetooth signal. This research characterizes previously neglected transmission delay effects. Through analytic modeling and simulation, the impact of this interference is determined to identify all facets of the interference issues. Results show that Bluetooth-induced transmission delays improve network performance in many scenarios. When isolating delay effects, the likelihood that WLAN STA signals collide with each other decreases, causing an overall increase in normalized throughput and decrease in expected delay for many network configurations. As wireless communication technologies become an integral part of national defense, it is imperative to understand every performance characteristic. For instance, if the Air Force uses IEEE 802.11 and wants to incorporate a Bluetooth piconet as well, the impact of concurrent operation should be known beforehand. Since IEEE 802.11 and Bluetooth technologies could become vital for the Air Force to maintain its position of air superiority, all the strengths, weaknesses, and limitations of these systems should be understood
Against the Linguistic Analogy
Recently it has been proposed that humans possess an innate, domain-specific moral faculty, and that this faculty might be fruitfully understood by drawing a close analogy with nativist theories in linguistics. This Linguistic Analogy (LA) hypothesizes that humans share a universal moral grammar. In this paper I argue that this conception is deeply flawed. After profiling a recent and appealing account of universal moral grammar, I suggest that recent empirical findings reveal a significant flaw, which takes the form of a dilemma: either there is something wrong with the moral grammar model because we do not actually possess the innate contents (rules, principles, and concepts) it says we have, or the moral grammar model is simply the wrong model of moral cognition. In light of this dilemma, I conclude we ought to be skeptical that the Linguistic Analogy can adequately serve as a general account of moral cognition
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