340 research outputs found
Mathematical tapas
No full textThis book contains a collection of exercises (called “tapas”) at undergraduate level, mainly from the fields of real analysis, calculus, matrices, convexity, and optimization. Most of the problems presented here are non-standard and some require broad knowledge of different mathematical subjects in order to be solved. The author provides some hints and (partial) answers and also puts these carefully chosen exercises into context, presents information on their origins, and comments on possible extensions. With stars marking the levels of difficulty, these tapas show or prove something interesting, challenge the reader to solve and learn, and may have surprising results. This first volume of Mathematical Tapas will appeal to mathematicians, motivated undergraduate students from science-based areas, and those generally interested in mathematics.This textbook presents a collection of interesting and sometimes original exercises for motivated students in mathematics. Written in the same spirit as Volume 1, this second volume of Mathematical Tapas includes carefully selected problems at the intersection between undergraduate and graduate level. Hints, answers and (sometimes) comments are presented alongside the 222 “tapas” as well as 8 conjectures or open problems. Topics covered include metric, normed, Banach, inner-product and Hilbert spaces; differential calculus; integration; matrices; convexity; and optimization or variational problems. Suitable for advanced undergraduate and graduate students in mathematics, this book aims to sharpen the reader’s mathematical problem solving abilities
CHARVAKA (LOKAYATA) PHILOSOPHY: HISTORY, PRINCIPLES, BELIEFS, RECENT RELEVANCE AND CRITICISM
No full textDr. Tapas Pal Mrityunjoy Kaibart
Semi-Adaptively Secure Offline Witness Encryption from Puncturable Witness PRF
Get PDFIn this work, we introduce the notion of puncturable witness pseudorandom function (pWPRF) which is a stronger variant of WPRF proposed by Zhandry, TCC 2016. The punctured technique is similar to what we have seen for puncturable PRFs and is capable of extending the applications of WPRF. Specifically, we construct a semi-adaptively secure offline witness encryption (OWE) scheme using a pWPRF, an indistinguishability obfuscation (iO) and a symmetric-key encryption (SKE), which enables us to encrypt messages along with NP statements. We show that replacing iO with extractability obfuscation, the OWE turns
out to be an extractable offline witness encryption scheme. To gain finer control over data, we further demonstrate how to convert our OWEs into offline functional witness encryption (OFWE) and extractable OFWE. All of our OWEs and OFWEs produce an optimal size ciphertext, in particular, encryption of a message is as small as the size of the message plus the security parameter multiplied with a constant, which is optimal for any public-key encryption scheme. On the other hand, in any previous OWE, the size of a ciphertext increases polynomially with the size of messages. Finally, we show that the WPRF of Pal et al. (ACISP 2019) can be extended to a pWPRF and an extractable pWPRF
A 'SACRED-BOURN' OF 2500 YEARS: The Culture of 'Do Ecology'
No full textCulture of ‘do Ecology’ is the pathway of environmental refurbishment. It means meeting the need of the current and future generation without ecological harm. To maintain this we have to search out different Green-gateways through which we can reach a sustainable environment. But actually human’s nature has molded to demand and more demand and we forget the health of the environment. To grip the resources we are moving and steeping forward from chilly Poles to interior ‘Aowa’ tribe area of Amazon and the actual frame of environment is being deteriorating. So in this phase we have needed some revamp measures and should be given our patient on traditional sciences like Scared Bourn. Author would like to maintain the health of environment with the application and implication of traditional science like Sacred Bourn through this paper. Keywords: ‘do ecology’, traditional science, Sacred Bourn, ‘Aowa’ tribe, green-gateways
FDI Spillovers, Innovation and the Role of Industrial Clusters: Evidence from Innovative Indian Manufacturing Firms
No full text© 2025, Elsevier B.V. The attached document (embargoed until 08/09/2026) is an author produced version of a paper published in Economic Modelling uploaded in accordance with the publisher’s self-archiving policy. The final published version (version of record) is available online at the link. Some minor differences between this version and the final published version may remain. We suggest you refer to the final published version should you wish to cite from it
Compact FE for Unbounded Attribute-Weighted Sums for Logspace from SXDH
Get PDFThis paper presents the first functional encryption (FE) scheme for the attribute-weighted sum (AWS) functionality that supports the uniform model of computation. In such an FE scheme, encryption takes as input a pair of attributes (x,z) where the attribute x is public while the attribute z is private. A secret key corresponds to some weight function f, and decryption recovers the weighted sum f(x)z. This is an important functionality with a wide range of potential real life applications, many of which require the attribute lengths to be flexible rather than being fixed at system setup. In the proposed scheme, the public attributes are considered as binary strings while the private attributes are considered as vectors over some finite field, both having arbitrary polynomial lengths that are not fixed at system setup. The weight functions are modeled as Logspace Turing machines.
Prior schemes [Abdalla, Gong, and Wee, CRYPTO 2020 and Datta and Pal, ASIACRYPT 2021] could only support non-uniform Logspace. The proposed scheme is built in asymmetric prime-order bilinear groups and is proven adaptively simulation secure under the well-studied symmetric external Diffie-Hellman (SXDH) assumption against an arbitrary polynomial number of secret key queries both before and after the challenge ciphertext. This is the best possible level of security for FE as noted in the literature. As a special case of the proposed FE scheme, we also obtain the first adaptively simulation secure inner-product FE (IPFE) for vectors of arbitrary length that is not fixed at system setup.
On the technical side, our contributions lie in extending the techniques of Lin and Luo [EUROCRYPT 2020] devised for payload hiding attribute-based encryption (ABE) for uniform Logspace access policies avoiding the so-called “one-use” restriction in the indistinguishability-based security model as well as the “three-slot reduction” technique for simulation-secure attribute-hiding FE for non-uniform Logspace devised by Datta and Pal [ASIACRYPT 2021] to the context of simulation-secure attribute-hiding FE for uniform Logspace
Polymerurus magnus Visvesvara 1963
No full textPolymerurus magnus Visvesvara, 1963 Records from India. MAHARASTRA: Nagpur— Visvesvara (1963); GENERAL RECORD: Naidu & Rao (2004). Habitat (as in Indian records). Freshwater; shallow parts of a tank. Distribution. Known only from India. Remarks. The species was found only once. The description was based on five specimens, which according to the author (Visvesvara 1963 ) differ from P. nodicaudus in virtue of the larger body size and the major length of the body spines (improperly called bristles). Schwank (1990) considered the species to be provisionally valid, although the synonymy between the two species seems to be likely. In our opinion further data are needed to confirm or disprove the current status of this species.Published as part of Chatterjee, Tapas & Todaro, M. Antonio, 2021, An annotated checklist of the chaetonotidan Gastrotricha from India, pp. 332-350 in Zootaxa 5027 (3) on page 343, DOI: 10.11646/zootaxa.5027.3.2, http://zenodo.org/record/544964
Chaetonotus (Schizochaetonotus) atrox Wilke 1954
No full textChaetonotus (Schizochaetonotus) atrox Wilke, 1954 Records from India. ANDHRA PRADESH: Bhimilipatnam, Visakhapatnam— Ganapati & Rao (1967), Sarma & Mohan (1981); ODISHA: Gopalpur, Bahuda estuary— Rao (1989). ANDAMAN & NICOBAR ISLANDS: Bomilla creek, East Bay, Hut Bay, Little Andaman— Rao (1980, 1993); LAKSHADWEEP: Kavaratti, Minicoy— Rao (1991); GENERAL RECORD: Naidu & Rao (2004). Habitat (as in Indian records). Marine, intertidal; fine and medium sands, 5 cm below surface between low and high water levels. Distribution. Cosmopolitan. Remarks. The Indian specimens agree with morphometric information on the species provided originally by Wilke (1954) from the Mediterranean Sea. We found in the morphometric account of the species provided by Naidu & Rao (2004) some incongruences with the known morphology of this taxon. First, they report the presence of refractile bodies on the head (presumably eye spots) and second, the say the anus is dorsal. Neither of these traits applies to C. atrox. Moreover, in the legend of Figure 65 they indicate Ferraguti (1996) as the original author of the provided figure. Likely this is material error, because in the references such a paper is not listed and prof. M. Ferraguti (University of Milan), author of many papers regarding the spermatology and reproductive system of the Gastrotricha, denies he is the author of that drawing (personal communication to MAT).Published as part of Chatterjee, Tapas & Todaro, M. Antonio, 2021, An annotated checklist of the chaetonotidan Gastrotricha from India, pp. 332-350 in Zootaxa 5027 (3) on page 338, DOI: 10.11646/zootaxa.5027.3.2, http://zenodo.org/record/544964
Memória do livro “Touros, tapas e meias pretas : crônicas de uma brasileira em Sevilha”
Get PDFTrabalho de conclusão de curso (graduação)—Universidade de Brasília, Faculdade de Comunicação, Departamento de Jornalismo, 2016.Esta memória de pesquisa expõe o processo de produção do livro Touros, tapas e meias pretas
– Crônicas de uma brasileira em Sevilha. Composto por 39 crônicas, que juntas totalizam 189
páginas de conteúdo, este produto tem como objetivo apresentar Sevilha, quarta maior cidade
da Espanha, e as peculiaridades que a tornam tão diferente do resto do mundo. A apresentação
é feita por meio de crônicas que relatam o dia-a-dia da autora nas terras espanholas e as
curiosidades e observações relativas à cultura sevilhana que a intrigaram, por irem de
encontro com a cultura brasileira. Para melhor compreender as características da cidade, as
crônicas também abordam a história da região e se aprofundam nos hábitos e costumes locais.This research memory exposes the production process of the book Bulls, tapas and black
socks - Chronicles of a Brazilian in Seville. Composed of 39 chronicles that together total 189
pages of content, this product aims to present Seville, Spain's fourth largest city, and the
peculiarities that make it so different from the rest of the world. The presentation is made
through chronicles that relate the day to day of the author in the Spanish lands and the
curiosities and observations related to the Sevillian culture that intrigued her, because they
come against the Brazilian culture. To better understand the characteristics of the city, the
chronicles also explain the history of the region and deepen in local habits and customs
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