scholarly journals Real Tropicalization and Analytification of Semialgebraic Sets

Author(s):  
Philipp Jell ◽  
Claus Scheiderer ◽  
Josephine Yu

Abstract Let $K$ be a real closed field with a nontrivial non-archimedean absolute value. We study a refined version of the tropicalization map, which we call real tropicalization map, that takes into account the signs on $K$. We study images of semialgebraic subsets of $K^n$ under this map from a general point of view. For a semialgebraic set $S \subseteq K^n$ we define a space $S_r^{{\operatorname{an}}}$ called the real analytification, which we show to be homeomorphic to the inverse limit of all real tropicalizations of $S$. We prove a real analogue of the tropical fundamental theorem and show that the tropicalization of any semialgebraic set is described by tropicalization of finitely many inequalities, which are valid on the semialgebraic set. We also study the topological properties of real analytification and tropicalization. If $X$ is an algebraic variety, we show that $X_r^{{\operatorname{an}}}$ can be canonically embedded into the real spectrum $X_r$ of $X$, and we study its relation with the Berkovich analytification of $X$.

1974 ◽  
Vol 26 (6) ◽  
pp. 1455-1465 ◽  
Author(s):  
Donald J. Mallory

It has been shown (Mallory and Sion [6]) that the problem of finding "limit" measures for inverse systems of measure spaces (Xi, μi)i∊I can be successfully attacked by establishing the existence of a “limit” measure on the product space , then considering the restriction to the inverse limit set .In this paper we use a similar point of view to establish conditions under which a system of Radón measures has a “limit” measure which is also Radón.


Healthcare ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 331
Author(s):  
Daniele Giansanti ◽  
Ivano Rossi ◽  
Lisa Monoscalco

The development of artificial intelligence (AI) during the COVID-19 pandemic is there for all to see, and has undoubtedly mainly concerned the activities of digital radiology. Nevertheless, the strong perception in the research and clinical application environment is that AI in radiology is like a hammer in search of a nail. Notable developments and opportunities do not seem to be combined, now, in the time of the COVID-19 pandemic, with a stable, effective, and concrete use in clinical routine; the use of AI often seems limited to use in research applications. This study considers the future perceived integration of AI with digital radiology after the COVID-19 pandemic and proposes a methodology that, by means of a wide interaction of the involved actors, allows a positioning exercise for acceptance evaluation using a general purpose electronic survey. The methodology was tested on a first category of professionals, the medical radiology technicians (MRT), and allowed to (i) collect their impressions on the issue in a structured way, and (ii) collect their suggestions and their comments in order to create a specific tool for this professional figure to be used in scientific societies. This study is useful for the stakeholders in the field, and yielded several noteworthy observations, among them (iii) the perception of great development in thoracic radiography and CT, but a loss of opportunity in integration with non-radiological technologies; (iv) the belief that it is appropriate to invest in training and infrastructure dedicated to AI; and (v) the widespread idea that AI can become a strong complementary tool to human activity. From a general point of view, the study is a clear invitation to face the last yard of AI in digital radiology, a last yard that depends a lot on the opinion and the ability to accept these technologies by the operators of digital radiology.


1967 ◽  
Vol 113 (501) ◽  
pp. 813-822 ◽  
Author(s):  
Örnulv Ödegård

My choice of Kraepelin as a point of departure for this lecture has definite reasons. If one wants to stay within the field of clinical psychiatry (as opposed to psychiatric history), that is as far back as one can reasonably go. By this no slight is intended upon the pre-Kraepelinian psychiatrists. For our topic Henry Maudsley would indeed have been a most appropriate starting point, and by no means for reasons of courtesy. His general point of view is admirably sound as a basis for the scientific study of prognosis in psychiatry. I quote: “There is no accident in madness. Causality, not casualty, governs its appearance in the universe, and it is very far from being a good and sufficient practice simply to mark its phenomena and straightway to pass on as if they belonged not to an order but to a disorder of events that called for no explanation.” On the special problem of prognosis he shows his clinical acumen by stating that the outlook is poor when the course of illness is insidious, but this only means that these cases develop their psychoses on the basis of mental deviations which go very far back in the patient's life, so that in fact they are generally in a chronic stage at the time of their first admission to hospital. Here he actually corrects a mistake which is still quite often made. He shows his dynamic attitude when he says that prognosis is to a large extent modified by external conditions, in particular by the attitude of friends and relatives. Maudsley's dynamic reasoning was limited by the narrow framework of the degeneration hypothesis of those days. He had a sceptical attitude towards classification, which he regarded as artificial and dangerously pseudo-exact. His own classification was deliberately provisional, with very wide groups. He held that a description of various sub-forms of chronic insanity was useless, as it would mean nothing but a tiresome enumeration of unconnected details.


1886 ◽  
Vol 3 (11) ◽  
pp. 481-489 ◽  
Author(s):  
J. J. H. Teall

If we take a general view of the present position of geological science, we are struck by the fact that, although there is substantial agreement amongst geologists on matters relating to the origin of the rocks usually designated as aqueous and igneous, the greatest diversity of opinion prevails with regard to the circumstances under which the so-called metamorphic rocks have been produced. Every fragment of evidence calculated to throw light on the origin of these rocks, therefore, deserves the most careful consideration. Of recent years special attention has been directed to the effects of mechanical energy in modifying the mineralogical and structural characters of rocks originally formed by aqueous and igneous agencies; and a suspicion has been aroused that it is in this direction that we must look for a solution of many of the problems connected with the origin of the crystalline schists. A visit to the Lizard Peninsula of Cornwall during the present summer has convinced me of the immense importance of this view so far as that district is concerned. That portion of the peninsula which lies south of a line drawn from Porthalla on the east to Polurrian Cove on the west is formed.partly of igneous rocks—such as gabbro, greenstone, serpentine, and granite—and partly of crystalline schists. The igneous rocks, in certain places, become foliated and sohistose and sometimes show a definite banding due to a variation in the relative proportions of the different constituents. In other words they present characters which are usually regarded as distinctive of the crystalline schists. There is, moreover, evidence to show that these characters are mainly the result of a yielding to earth-pressure subsequent to the consolidation of the original rock. At the present moment, having just returned from the district, I am unable to treat the subject from a general point of view with any prospect of success; but it has occurred to me that some details with regard to one of the rocks may not be without interest to members of the Association.


1897 ◽  
Vol 29 (3) ◽  
pp. 485-549
Author(s):  
M. Gaster

More marvellous and more remarkable than the real conquests of Alexander are the stories circulated about him, and the legends which have clustered round his name and his exploits. The history of Alexander has, from a very early period, been embellished with legends and tales. They spread from nation to nation during the whole of the ancient times, and all through the Middle Ages. Many scholars have followed up the course of this dissemination of the fabulous history of Alexander. It would, therefore, be idle repetition of work admirably done by men like Zacher, Wesselofsky, Budge, and others, should I attempt it here. All interested in the legend of Alexander are familiar with those works, where also the fullest bibliographical information is to be found. I am concerned here with what may have appeared to some of these students as the bye-paths of the legend, and which, to my mind, has not received that attention which is due to it, from more than one point of view. Hitherto the histories of Alexander were divided into two categories; the first were those writings which pretended to give a true historical description of his life and adventures, to the exclusion of fabulous matter; the other included all those fabulous histories in which the true elements were smothered under a great mass of legendary matter, the chief representative of this class being the work ascribed to a certain Callisthenes. The study of the legend centred in the study of the vicissitudes to which this work of (Pseudo-) Callisthenes had been exposed, in the course of its dissemination from the East, probably from its native country, Egypt, to the countries of the West.


2016 ◽  
Vol 12 (S329) ◽  
pp. 369-372
Author(s):  
C. L. Fletcher ◽  
V. Petit ◽  
Y. Nazé ◽  
G. A. Wade ◽  
R. H. Townsend ◽  
...  

AbstractRecent spectropolarimetric surveys of bright, hot stars have found that ~10% of OB-type stars contain strong (mostly dipolar) surface magnetic fields (~kG). The prominent paradigm describing the interaction between the stellar winds and the surface magnetic field is the magnetically confined wind shock (MCWS) model. In this model, the stellar wind plasma is forced to move along the closed field loops of the magnetic field, colliding at the magnetic equator, and creating a shock. As the shocked material cools radiatively it will emit X-rays. Therefore, X-ray spectroscopy is a key tool in detecting and characterizing the hot wind material confined by the magnetic fields of these stars. Some B-type stars are found to have very short rotational periods. The effects of the rapid rotation on the X-ray production within the magnetosphere have yet to be explored in detail. The added centrifugal force due to rapid rotation is predicted to cause faster wind outflows along the field lines, leading to higher shock temperatures and harder X-rays. However, this is not observed in all rapidly rotating magnetic B-type stars. In order to address this from a theoretical point of view, we use the X-ray Analytical Dynamical Magnetosphere (XADM) model, originally developed for slow rotators, with an implementation of new rapid rotational physics. Using X-ray spectroscopy from ESA’s XMM-Newton space telescope, we observed 5 rapidly rotating B-types stars to add to the previous list of observations. Comparing the observed X-ray luminosity and hardness ratio to that predicted by the XADM allows us to determine the role the added centrifugal force plays in the magnetospheric X-ray emission of these stars.


2019 ◽  
Vol 11 (24) ◽  
pp. 6947 ◽  
Author(s):  
Markus Kantsperger ◽  
Hannes Thees ◽  
Christian Eckert

This study applies an adapted approach of the traditional view on local participation in tourism development. First, the study mainly focuses on exploring the patterns behind participation instead of the reasons for participation. Second, a case is chosen that transcends the interest in researching participation in developing countries. Third, the study focuses on non-tourism related residents, an under-researched group of stakeholders. It is thus investigated how non-tourism related residents face the process of participation in tourism development and what the main barriers and drivers are in this regard. To discuss this issue, the study takes a closer look at the case of Bad Reichenhall, an Alpine Destination in Germany. 15 qualitative interviews are conducted with non-tourism related residents and further evaluated through a qualitative content analysis. The results underline that tourism represents a public domain that concerns all stakeholders of a destination. The typology derived throughout the study reflects the heterogeneity of non-tourism related residents, coming up with four types of non-tourism related residents facing participation in tourism development rather differently. Various barriers and drivers are revealed that impact non-tourism related residents from both a personal and general point of view. Non-tourism related residents turn out as a promising and important target group in the discourse of stakeholder participation in tourism development.


1973 ◽  
Vol 16 (3) ◽  
pp. 405-415
Author(s):  
Gerard Elie Cohen

An inverse limit of finite groups has been called in the literature a pro-finite group and we have extensive studies of profinite groups from the cohomological point of view by J. P. Serre. The general theory of non-abelian modules has not yet been developed and therefore we consider a generalization of profinite abelian groups. We study inverse systems of discrete finite length R-modules. Profinite modules are inverse limits of discrete finite length R-modules with the inverse limit topology.


Author(s):  
Anni Lappela

Mountains and City as Contrary Spaces in the Prose of Alisa Ganieva I analyze Alisa Ganieva’s novel Prazdnichnaia gora (2012) and her novella Salam tebe, Dalgat! (2010) from a geocritical (Westphal, Tally) point of view. Ganieva was born in 1985 in Moscow, but she grew up in Dagestan, in North Caucasia. Since 2002, she has lived in Moscow. All Ganieva’s novels are set in present-day Dagestan, not only in the capital Makhachkala but also in the countryside.  I study the ways the two main spaces and main milieus, the mountains and the city, oppose each other in Prazdnichnaia gora. I also analyze how this opposition constructs the utopian and dystopian discourses of the novel. In this high/low opposition, the mountains appear as the utopian place of a better future, and the city in the lowlands is depicted as a dystopian place of the present-day life. The texts’ multilayered time is also part of my analysis, which follows Westphal’s idea of the stratigraphy of time. Furthermore, the mountains are associated with the traditional way of life and the Soviet past. In this way, the mountains have two kinds of roles in the texts. Nevertheless, the city is a central element of the postcolonial dystopian discourse of Prazdnichnaia gora. In my opinion, Ganieva’s texts problematize referentiality, one of the key concepts of geocriticism. Whilst the city tends to be very referential, the mountains escape the referential relationship to the “real” geographical space.


2017 ◽  
Vol 20 (30) ◽  
pp. 17-37
Author(s):  
Santiago Álvarez García

El presente artículo muestra cómo la crítica humeana a los fundamentos del racionalismo moral y a sus consecuencias en el terreno de las ideas educativas propició un cambio significativo en la comprensión de los objetivos de la educación moral que pasaron de buscar el perfeccionamiento de la agencia, a perseguir la perfección y el refinamiento de las capacidades del individuo como espectador y evaluador moral imparcial. Esta trasformación de la finalidad y del currículo de la educación moral será la solución que Hume ofrezca a los problemas de parcialidad derivados de la historicidad y la caducidad del general point of view como criterio último para el juicio moral. La exposición constante del educando a todas las formas históricas de la belleza, junto con la poesía, la literatura, el estudio de la historia y la filosofía, constituirán para Hume la base de esta revolución pedagógica.


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