1,933 research outputs found
Michi N. Weglyn, 72, advocate for interned Japanese-Americans
No full textAn obituary for Michi Weglyn written by Eric Page with a note from Kimmie Ito written on it.These materials are from box 73 and 74 of the Frank Chin Papers. The Frank Chin Papers contain personal and professional correspondence between Frank Chin and Michi Weglyn relating to particular projects on which either author was working as well as files related to the Day of Remembrance Tribute to Michi Weglyn
New insights on the (non-)hardness of circuit minimization and related problems
No full textThe Minimum Circuit Size Problem (MCSP) and a related problem (MKTP) that deals with time-bounded Kolmogorov complexity are prominent candidates for NP-intermediate status. We show that, under very modest cryptographic assumptions (such as the existence of one-way functions), the problem of approximating the minimum circuit size (or time-b^ounded Kolmogorov complexity) within a factor of n^{1−o(1)} is indeed NPintermediate. To the best of our knowledge, these problems are the first natural NP-intermediate problems under the existence of an arbitrary one-way function. Our technique is quite general; we use it also to show that approximating the size of the largest clique in a graph within a factor of n^{1−o(1)} is also NP-intermediate unless NP ⊆ P/poly.
We also prove that MKTP is hard for the complexity class DET under non-uniform NC0 reductions. This
is surprising, since prior work on MCSP and MKTP had highlighted weaknesses of “local” reductions such as NC0 reductions . We exploit this local reduction to obtain several new consequences:
—MKTP is not in AC0[p].
—Circuit size lower bounds are equivalent to hardness of a relativized version MKTP^A of MKTP under a class of uniform AC0 reductions, for a significant class of sets A.
—Hardness of MCSP^A implies hardness of MKTP^A for a significant class of sets A. This is the first result directly relating the complexity of MCSP^A and MKTP^A, for any A.Peer reviewed© ACM, 2019. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in ACM Transactions on Computation Theory (TOCT), {Vol.11, Iss.4, (September 2019)} http://doi.acm.org/10.1145/3349616
Width-parameterized SAT: time-space tradeoffs,
No full textAlekhnovich and Razborov (2002) presented an algorithm that solves SAT on instances ϕ of size n and tree-width TW(ϕ), using time and space bounded by 2O(TW(ϕ))nO(1). Although several follow-up works appeared over the last decade, the first open question of Alekhnovich and Razborov remained essentially unresolved: Can one check satisfiability of formulas with small tree-width in polynomial space and time as above? We essentially resolve this question, by (1) giving a polynomial space algorithm with a slightly worse run-time, (2) providing a complexity-theoretic characterization of bounded tree-width SAT, which strongly suggests that no polynomial-space algorithm can run significantly faster, and (3) presenting a spectrum of algorithms trading off time for space, between our PSPACE algorithm and the fastest known algorithm.
First, we give a simple algorithm that runs in polynomial space and achieves run-time 3TW(ϕ)lognnO(1), which approaches the run-time of Alekhnovich and Razborov (2002), but has an additional log n factor in the exponent. Then, we conjecture that this annoying log n factor is in general unavoidable.
Our negative results show our conjecture true if one believes a well-known complexity assumption, which is the SC ≠ NC conjecture and its scaled variants. Technically, we base our result on the following lemma. For arbitrary k, SAT of tree-width logkn is complete for the class of problems computed by circuits of logarithmic depth, semi-unbounded fan-in and size 2O(logkn) (SAC1 when k=1). Problems in this class can be solved simultaneously in time-space (2O(logk+1n),O(logk+1n)), and also in (2O(logkn), 2O(logkn)). Then, we show that our conjecture (for SAT instances with poly-log tree-width) is equivalent to the question of whether the small-space simulation of semi-unbounded circuit classes can be sped up without incurring a large space penalty. This is a recasting of the conjecture that SAC1 (and even its subclass NL) is not contained in SC.
Although we cannot hope for an improvement asymptotically in the exponent of time and space, we introduce a new algorithmic technique which trades constants in the exponents: for each ε with 0<ε<1, we give an algorithm in time-space
(31.441(1−ε)TW(ϕ)log|ϕ||ϕ|O(1),22εTW(ϕ)|ϕ|O(1)).
We systematically study the limitations of our technique for trading off time and space, and we show that our bounds are the best achievable using this technique.Licensed under a Creative Commons Attribution License (CC-BY) http://creativecommons.org/licenses/by/3.0/Peer reviewe
The non-hardness of approximating circuit size
No full textThe Minimum Circuit Size Problem (MCSP) has been the focus of intense study recently; MCSP is hard for SZK under rather powerful reductions, and is provably not hard under “local” reductions computable in TIME(n^0.49). The question of whether MCSP is NP-hard (or indeed, hard even for small subclasses of P) under some of the more familiar notions of reducibility (such as many-one or Turing reductions computable in polynomial time or in AC0) is closely related to many of the longstanding open questions in complexity theory.
All prior hardness results for MCSP hold also for computing somewhat weak approximations to the circuit complexity of a function. Some of these results were proved by exploiting a connection to a notion of time-bounded Kolmogorov complexity (KT) and the corresponding decision problem (MKTP). More recently, a new approach for proving improved hardness results for MKTP was developed, but this approach establishes only hardness of extremely good approximations of the form 1+o(1), and these improved hardness results are not yet known to hold for MCSP. In particular, it is known that MKTP is hard for the complexity class DET under nonuniform AC0 many-one reductions, implying MKTP is not in AC0[p] for any prime p. It was still open if similar circuit lower bounds hold for MCSP. One possible avenue for proving a similar hardness result for MCSP would be to improve the hardness
of approximation for MKTP beyond 1 + o(1) to omega(1), as KT-complexity and circuit size are
polynomially-related. In this paper, we show that this approach cannot succeed.
More specifically, we prove that PARITY does not reduce to the problem of computing superlinear approximations to KT-complexity or circuit size via AC0-Turing reductions that make O(1) queries. This is significant, since approximating any set in P/poly AC0-reduces to just one query of a much worse approximation of circuit size or KT-complexity. For weaker approximations, we also prove non-hardness under more powerful reductions. Our non-hardness results are unconditional, in contrast to conditional results presented in [7] (for more powerful reductions, but for much worse approximations). This highlights obstacles that would have to be overcome by any proof that MKTP or MCSP is hard for NP under AC0 reductions. It may also be a step toward confirming a conjecture of Murray and Williams, that MCSP is not NP-complete under logtime-uniform AC0 many-one reductions.Peer reviewe
«Tout à fait Eric... tout à fait !». Quand le sociologue sert de ballon de football aux médias. Souvenirs et réflexions préliminaires
No full textThe sociologist as media football. Reminiscences and preliminary reflections.
Eric Dunning [5-15].
This paper offers an ironical account of various experiments of the author with the press, as specialist of the violence's in stadiums analysis. Functional logics of medias, existence of hidden agendas, lack of knowledge to the files make difficult the expression by journalists of real sociological analysis, especially in the TV. The tabloid press in particular has a manipulatory use of talk that it appeals to the researchers, and contributes to the social construction of the hooligan's phenomenom. Nevertheless, they are some possibilities of cooperation with the quality press, in the context of documentary programmes.Quand le sociologue sert de ballon de football aux médias. Souvenirs et réflexions préliminaires.
Eric Dunning [5-15].
Cet article livre un compte-rendu ironique des diverses expériences de l'auteur avec la presse, en qualité de spécialiste de l'analyse des violences dans les stades. Les logiques de fonctionnement des médias, l'existence d'agendas cachés, le manque de connaissance des dossiers par les journalistes, rendent difficile l'expression d'analyses sociologiques dignes de ce nom, à la télévision spécialement. La presse «tabloïd» en particulier fait un usage manipulatoire des propos qu'elle sollicite des chercheurs, et contribue à la construction sociale du phénomène hooligan. Des possibilités de coopération existent cependant dans le cadre de programmes documentaires, avec la presse de qualité.Dunning Eric. «Tout à fait Eric... tout à fait !». Quand le sociologue sert de ballon de football aux médias. Souvenirs et réflexions préliminaires. In: Politix, vol. 9, n°36, Quatrième trimestre 1996. Usages sociaux des sciences sociales, sous la direction de Jean-Baptiste Legavre et Erik Neveu. pp. 5-15
Series of picture books of Eric Hill about Spot
No full textHill je avtor in hkrati ilustrator svojih slikanic, katere so izjemno priljubljene med otroci. Nad njimi so navdušeni tudi odrasli, saj je lik Pikija zelo preprost, karakter približan otroku in tako nima negativnih vplivov na bralca. Slikanice so primerno oblikovane za otroke stare od 11 mesecev pa tja do vstopa v šolo. Teme slikanic so vzete iz vsakdanjega življenja in v njih se najde tudi predšolski otrok. Diplomsko delo je napisano na podlagi primerjanja slikanic Erica Hilla, dostopnih v Sloveniji in uporabe le-teh pri praktičnem delu v vrtcu. Slikanice z naslovi Pozdravljen, Piki! Knjižica z ročno lutko (2014), Pikijev sprehod skozi gozd (1994), Piki obišče kmetijo (1991), Piki gre na izlet (2003), Piki obišče babico in dedka (2014) so bile podrobno analizirane in so vse v slovenskem jeziku. Izbrana dela Erica Hilla označujemo kot slikanice, saj imajo več ilustracij kot besedila, ki je razporejeno po vsej slikanici. Teme ter jezikovne prvine upoštevajo otrokov kognitivni razvoj. Zapisane so tudi informacije o avtorju, nastanek slikanic o Pikiju in skupne značilnosti vseh njegovih ostalih del, pojasnjena je tudi vloga glavnega literarnega lika. Opisana je novost v slikanicah, zavihek, katerega pred Hillom še nihče ni uporabil.Hill is both the author and the illustrator of his picture books which are very popular among children. Adults are impressed by them as well since the figure of Spot is very simple, the puppy\u27s character is close to children and, therefore, has no negative impact on the reader. The picture books are properly designed for children from the age of 11 months up to the school age. Topics of the picture books are taken from everyday life which a preschool child is also familiar with. The thesis is written on the basis of comparison of the picture books by Eric Hill, available in Slovenia, and their usage in practical work in kindergartens. Picture books entitled Hello Spot! Booklet with a hand puppet (2014), Spot\u27s walk in the woods (1994), Spot goes to the farm (1991), Spot’s noisy walk (2003), Spot visits his grandparents (2014) were analysed in detail and are all in the Slovenian language. The selected works of Eric Hill are referred to as picture books, for they have more illustrations, which are arranged throughout the picture book, then text. The topics and linguistic elements consider the child\u27s cognitive development. Information about the author, the origin of picture books about Spot, and common characteristics of his other works are describedmoreover, the role of the main literary character is explained as well as the flaps – a novelty in picture books that no one had used before Hill
First in the Nation in Education : Final Report,1984.
No full textThis report is one step in an ongoing process of change and is a plea for commitment for high standards in education in Iowa. Contains the final reports of the six subcommittees as adopted by the Excellence in Education Task Force, and the five recommendations made by the Task Force
Experimental methods applied to the computation of integer sequences
No full textWe apply techniques of experimental mathematics to certain problems in number theory and combinatorics. The goal in each case is to understand certain integer sequences, where foremost we are interested in computing a sequence faster than by its definition. Often this means taking a sequence of integers that is defined recursively and rewriting it without recursion as much as possible. The benefits of doing this are twofold. From the view of computational complexity, one obtains an algorithm for computing the system that is faster than the original; from the mathematical view, one obtains new information about the structure of the system.
Two particular topics are studied with the experimental method. The first is the recurrence a(n) = a(n - 1) + gcd(n, a(n - 1)), which is shown to generate primes in a certain sense. The second is the enumeration of binary trees avoiding a given pattern and extensions of this problem. In each of these problems, computing sequences quickly is intimately connected to understanding the structure of the objects and being able to prove theorems about them.Ph.D.Includes bibliographical references (p. 57-59)by Eric Samuel Rowlan
Video of SHINE! by Kim Scott feat. Blake Aaron and Philip N. Davis
No full textLive performance from the album release concert for "SHINE!", Kim's 5th album on the Innervision Records label. Kim Scott, flute; Phil Davis, keys; Eric Essix, guitar; Sean Michael Ray, bass; James "PJ" Spraggins, drums; Kelley Oneal, sax and flut
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