437 research outputs found
Generalized composition law from 2x2 matrices
Many results that are difficult can be found more easily by using a
generalization in the complex plane of Einstein's addition law of parallel
velocities. Such a generalization is a natural way to add quantities that are
limited to bounded values. We show how this generalization directly provides
phase factors such as the Wigner angle in special relativity and how this
generalization is connected in the simplest case with the composition of 2x2 S
matrices.Comment: Accepted for publication in Am. J. Phy
Efficient Mechanisms for Access to Storage with Imperfect Competition in Gas Markets
Scarce storage capacity and distortions in access to gas storage are considered causes of market foreclosure in liberalized gas markets. We consider rules currently adopted in Europe for storage rationing and propose efficient rationing mechanism based on the value of storage, when other flexibility inputs are available. Firstly we analyse productive efficiency issues neglecting vertical restraints and strategic behaviour in the final market. Then we assume imperfect compettion in the downstream market for gas supplies, given the avaialbility of storage capacity upstream. We consider effciency issues in a two stage model comparing regulated storage tariffs â coupled with a centralizedrationing mechanism â with storage auctions. Finally we consider as an optimal mechanism the allocation of storage arising from welfare maximization by a social planner. We find that it is usually optimal to maximize the amount of storage capacity allocated to new entrants in the gas markets. Storage auctions deviates from the optimal mechanism, but still improve efficiency, with respect to current mechanisms, to the extent that they allocate storage according to its value. Furthermore storage allocation appear to be an extremeley powerful mechanism to improve competition and efficiency in gas markets.Liberalization, Auctions, Essential Facilities
Oriental Inspirations in Russian Opera at the Time of Catherine the Great
During the reign of Catherine the Great (1762â1796) the problem of the Turkish threat over Europe had become an excuse for negotiations aiming at stabilizing the geopolitical balance between the European countries. This preoccupation was present in the diplomatic discourse, where after its âdeclineâ, the Ottoman Empire was evaluated as a fake giant, incapable of representing a serious military menace. However, the presence of âThe Turkâ in the mind of Western audiences is attested by the diffusion of Oriental themes in different works of art. In the field of musical theatre, these can be found, among others, in such operatic performances as the opĂ©ra comique La rencontre imprĂ©vue, ou Les pĂšlerins de la Mecque by Christoph Willibald Gluck (1763), and Mozartâs Singspiel Die EntfĂŒhrung aus dem Serail (1782). In Russia, the response to the Eastern Question was the âGreek projectâ â a series of geopolitical plans that the Empress developed with her counsellors Aleksandr Bezborodko and Grigory Potyomkin, which foresaw the occupation of the Ottoman Empire, and its subsequent passing over to the rule of Catherineâs grandson Konstantin Pavlovich. According to those plans, in 1781 Catherine signed a secret alliance with the Austrian emperor Joseph II, which was to be confirmed by the subsequent journey of her son Pavel Petrovich to the Habsburg Court. While creating secret coalitions at international level, Catherine undertook a propagandistic campaign putting an emphasis on her policy. Musical theatre was involved in such initiatives, according to the traditional role of opera as a vehicle for the so-called âscenario of powerâ (Wortman). The following paper addresses the impact of the âGreek projectâ on the Russian culture by examining some cases taken from the opera theatre, in which early oriental inspirations emerge. References to the East are understood in terms of subject, provenance of the characters, collocation of the action and the consequent coleur locale evoked with set costumes and music. Four Russian titles will be considered in various ways: Fevej and NaÄalânoe upravlenie Olega [The Beginnings of the Reign of Oleg] on librettos by Catherine II, Tomyris, reine des Massagets [Tomyris, queen of the Massageteans] by Louis Dancourt, and Zelâmira i Smelon by Pavel Potyomkin. Apart from these, two Italian works will be addressed briefly: the cantata Atene edificata by Domenico Cimarosa and the opera Alessandro e Timoteo by Giuseppe Sarti.Institute for Russian and Eurasian Studies. Uppsala University. Sweden15517
International Networking in Russian Music Theatre around 1800: Sheremetev, Yusupov and Grand Duke Pavel Petrovich
This article investigates the role played by aristocrats in the exchange of repertoire and musical personnel between Russia and Western Europe in the late eighteenth and early nineteenth centuries. It discusses the involvement of three significant figures in the political and cultural milieus of the Russian Empire: Count Nikolay Petrovich Sheremetev (1751-1809), Prince Nikolay Borisovich Yusupov (1750-1831) and the Grand Duke Pavel Petrovich Romanov (who ruled as Paul I from 1796 to 1801). The central focus is on Sheremetev, whose correspondence with Marie-Francois Hivart, a Parisian cellist he met during a grand tour, allows us to reconstruct a clear picture of how French opera was imported and adapted at his estate theatres in the Moscow area. Yusupov and the grand duke likewise established international musical contacts during their European tours of the 1770s and 80s, and exploited them in their private and public theatrical activities in Russia. Yusupov, who was particularly fond of Italian opera, may be rep? Tried as Sheremetev's counterpart in St Petersburg, while Tsarevich Pavel Petrovich channelled the musical contacts he established in Italy to the Russian court and crown theatres.Together, these cases suggest some of the ways in which Russia was entangled in European musical life around 1800, revealing mechanisms of exchange in which grand tours, diplomatic contacts and the personal interests of patrons played a significant part
IP Flow Mobility support for Proxy Mobile IPv6 based networks
The ability of offloading selected IP data traffic from 3G to WLAN access networks is considered a key feature in the upcoming 3GPP specifications, being the main goal to alleviate data congestion in celular networks while delivering a positive user experience. Lately, the 3GPP has adopted solutions that enable mobility of IP-based wireless devices relocating mobility functions from the terminal to the network. To this end, the IETF has standardized Proxy Mobile IPv6 (PMIPv6), a protocol capable to hide often complex mobility procedures from the mobile devices.
This thesis, in line with the mentioned offload requirement, further extends Proxy Mobile IPv6 to support dynamic IP flow mobility management across access wireless networks according to operator policies. In this work, we assess the feasibility of the proposed solution and provide an experimental analysis based on a prototype network setup, implementing the PMIPv6 protocol and the related enhancements for flow mobility support.
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La capacitĂ di spostare flussi IP da una rete di accesso 3G ad una di tipo WLAN Ăš considerata una caratteristica chiave nelle specifiche future di 3GPP, essendo il principale metodo per alleviare la congestione nelle reti cellulari mantenendo al contempo una ragionevole qualitĂ percepita dall'utente. Recentemente, 3GPP ha adottato soluzioni di mobilitĂ per dispositivi con accesso radio basato su IP, traslando le funzioni di supporto dal terminale alla rete, e, a questo scopo, IETF ha standardizzato Proxy Mobile IPv6 (PMIPv6), un protocollo studiato per nascondere le procedure di mobilitĂ ai sistemi mobili.
Questa tesi, in linea con la citata esigenza di spostare flussi IP, estende ulteriormente PMIPv6 per consentire il supporto alla mobilitĂ di flussi tra diverse reti di accesso wireless, assecondando le regole e/o politiche definite da un operatore.
In questo lavoro, ci proponiamo di asserire la fattibilitĂ della soluzione proposta, fornendo un'analisi sperimentale di essa sulla base di un prototipo di rete che implementa il protocollo PMIPv6 e le relative migliorie per il supporto alla mobilitĂ di flussiope
Increasing Informal Learning Opportunities for Teachers in the School Setting
This paper comprehensively defines how to implement informal learning strategies into the classroom setting using Marsick and Watkinsâs Incidental Learning Model (2001). Existing barriers that stand between educators and informal learning in the school setting are explained. Implications for removing said inhibitors while increasing learning are explicated
A Study of Automotive Security : CAN Bus Intrusion detection Systems, Attack Surface, and Regulations
The innovation in the automotive sector enhanced the technology implemented in vehicles by the manufacturers. Consequently, the overall driving experience improved, thanks to the introduction of better safety, utility, and entertainment systems. Moreover, automobiles began collecting and exchanging data with the external world through different communication protocols. However, these additions have started to attract attention from security experts. More importantly, malevolent attackers have exploited the technologies and their related attack points to carry out malicious activities to cause data security and safety issues. These issues have led to establishing standards and regulations (ISO 21434, UNECE 155, etc.) that redefine vehicle design and development by incorporating security protocols and requirements necessary to create secure automobiles. However, these documents analyze the problem at a high level and do not dwell on practical solutions implementation analysis. This work presents an in-depth study of in-vehicle communication concerns via Controller Area Network (CAN) bus safety problems analysis with different proposed solutions. Specifically, a survey of Intrusion Detection Systems developed in the literature is brought up: simulation of three CAN bus intrusion detection systems against various attacks. The results show effectiveness against disruptive attacks, i.e., with numerous messages sent in a short period of time, but conversely have difficulty detecting more targeted attacks with few transmitted packets. The solutions analysis is an excellent starting point for security engineers to be able to develop Intrusion Detection Systems for the CAN bus capable of detecting attacks that will become increasingly complex and difficult to counter over time
The Harmonic Balance method for the solution of nonlinear circuit and field problems with harmonic sources and its integration with a commercial simulation software
This thesis treats the Harmonic Balance method applied to nonlinear circuit and field problems. The main topic is the integration of the Harmonic Balance method in a commercial FEM solver. The procedure is shown and the related code is tested in some significant examplesope
The Ways to Russia of Alfredo Casella
The relationship of Alfredo Casella with the Russian musical culture took place on several levels, ranging from artistic interest in the production of \u2018the Five\u2019 to interpersonal relationships that the composer maintained at different times of his life. During his early years in Paris he became passionate about such composers as Musorgsky and Balakirev, which would have much impact on the renewal of the European musical language. In line with the recovery of folklore are the Chansons he arranged in 1912 for a competition organized by the Maison du Lied, an association founded in 1908 in Paris and Moscow that proposed to perpetuate and enrich the tradition of Lied and of popular song. Casella visited St Petersburg with Henri Casadesus\u2019s Soci\ue9t\ue9 des instruments anciens, invited to give concerts of ancient music in 1907-08 and 1909, by Aleksandr Ziloti and Sergey Kusevitsky respectively. Subsequently, in 1926 the composer went to the USSR in order to promote the contemporary music. This trip originated from the relationships he had established with some exponents of Russian musical modernism: Boris Asaf\u2019yev, Viktor Belyayev, and more generally the Association for Contemporary Music\u2019 \u2013 Moscow branch of the International Society for Contemporary Music. The production of the composer was publicized by the group in several issues of their magazine, Contemporary music, and the musician was invited to contribute some writings for the journal. Evidence of these initiatives can be found in some documents preserved at the Casella Archive at the Fondazione Cini in Venice. My contribution will consider these materials, putting them in connection with the existing literature on the Russian musical life in the early years of the 20th century (e. g. Frolova-Walker) and on the activity of Casella in Russia (Lebed\u2019, Kirillina). More importantly, attention will be paid to the critical debate emerging on the mentioned periodical, in reference to the coeval situation within the USSR and in Western Europe. As well as the debate that developed in the 1920s among music theoreticians within the divided community of Soviet musicians, the international contacts upheld among different communities were to be interrupted by the subsequent course of events in the cultural life of the Soviet Union. Still, they represent an element of continuity in the long-standing tradition of Russian \u2013 Italian Musical Connections that are at the centre of the 2018 Conference of the Institute for Russian Music Studies
Comparative Analysis of the United States Patent Law and the New Industrial Property Code of Brazil
Brazil promulgated a new Industrial Property Code in 1996 that significantly changed its patent law. In this Article, Mr. Giust compares the Brazilian statute to patent law in the United States. Through detailed analysis, the Article shows that despite the vastly different economic and social needs of both nations, the recent changes have actually brought the two patent systems closer together. As the author argues, this trend toward convergence reflects the two nations\u27 commitment to the TRIPs Agreement, and to that extent, strongly supports the view that global patent harmonization is possible.
This Article\u27s comparative analysis covers numerous aspects of the two patent systems. It first lays the foundation from a systemic, as well as constitutional, perspective. It then compares and contrasts the various procedures and requirements of patent protection under both systems, including patent eligibility, patentability requirements, ownership and assignment rights, compulsory licensing, as well as registration requirements. Finally, it analyzes the use of injunctions, compensatory damages, seizures of goods, and criminal penalties as means to enforce patents under the two systems. Through careful consideration, the author shows that the patent laws of the United States and Brazil, despite some significant differences, have a number of important similarities
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