Toward a complexity theory for randomized search heuristics : black-box models

Randomized search heuristics are a broadly used class of general-purpose algorithms. Analyzing them via classical methods of theoretical computer science is a growing field. While several strong runtime bounds exist, a powerful complexity theory for such algorithms is yet to be developed. We contribute to this goal in several aspects. In a first step, we analyze existing black-box complexity models. Our results indicate that these models are not restrictive enough. This remains true if we restrict the memory of the algorithms under consideration. These results motivate us to enrich the existing notions of black-box complexity by the additional restriction that not actual objective values, but only the relative quality of the previously evaluated solutions may be taken into account by the algorithms. Many heuristics belong to this class of algorithms. We show that our ranking-based model gives more realistic complexity estimates for some problems, while for others the low complexities of the previous models still hold. Surprisingly, our results have an interesting game-theoretic aspect as well.We show that analyzing the black-box complexity of the OneMaxn function class—a class often regarded to analyze how heuristics progress in easy parts of the search space—is the same as analyzing optimal winning strategies for the generalized Mastermind game with 2 colors and length-n codewords. This connection was seemingly overlooked so far in the search heuristics community.Randomisierte Suchheuristiken sind vielseitig einsetzbare Algorithmen, die aufgrund ihrer hohen Flexibilität nicht nur im industriellen Kontext weit verbreitet sind. Trotz zahlreicher erfolgreicher Anwendungsbeispiele steckt die Laufzeitanalyse solcher Heuristiken noch in ihren Kinderschuhen. Insbesondere fehlt es uns an einem guten Verständnis, in welchen Situationen problemunabhängige Heuristiken in kurzer Laufzeit gute Lösungen liefern können. Eine Komplexitätstheorie ähnlich wie es sie in der klassischen Algorithmik gibt, wäre wünschenswert. Mit dieser Arbeit tragen wir zur Entwicklung einer solchen Komplexitätstheorie für Suchheuristiken bei. Wir zeigen anhand verschiedener Beispiele, dass existierende Modelle die Schwierigkeit eines Problems nicht immer zufriedenstellend erfassen. Wir schlagen daher ein weiteres Modell vor. In unserem Ranking-Based Black-Box Model lernen die Algorithmen keine exakten Funktionswerte, sondern bloß die Rangordnung der bislang angefragten Suchpunkte. Dieses Modell gibt für manche Probleme eine bessere Einschätzung der Schwierigkeit. Wir zeigen jedoch auch, dass auch im neuen Modell Probleme existieren, deren Komplexität als zu gering einzuschätzen ist. Unsere Ergebnisse haben auch einen spieltheoretischen Aspekt. Optimale Gewinnstrategien für den Rater im Mastermindspiel (auch SuperHirn) mit n Positionen entsprechen genau optimalen Algorithmen zur Maximierung von OneMaxn-Funktionen. Dieser Zusammenhang wurde scheinbar bislang übersehen. Diese Arbeit ist in englischer Sprache verfasst

Probabilistic methods for distributed information dissemination

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 457-484).The ever-increasing growth of modern networks comes with a paradigm shift in network operation. Networks can no longer be abstracted as deterministic, centrally controlled systems with static topologies but need to be understood as highly distributed, dynamic systems with inherent unreliabilities. This makes many communication, coordination and computation tasks challenging and in many scenarios communication becomes a crucial bottleneck. In this thesis, we develop new algorithms and techniques to address these challenges. In particular we concentrate on broadcast and information dissemination tasks and introduce novel ideas on how randomization can lead to powerful, simple and practical communication primitives suitable for these modern networks. In this endeavor we combine and further develop tools from different disciplines trying to simultaneously addresses the distributed, information theoretic and algorithmic aspects of network communication. The two main probabilistic techniques developed to disseminate information in a network are gossip and random linear network coding. Gossip is an alternative to classical flooding approaches: Instead of nodes repeatedly forwarding information to all their neighbors, gossiping nodes forward information only to a small number of (random) neighbors. We show that, when done right, gossip disperses information almost as quickly as flooding, albeit with a drastically reduced communication overhead. Random linear network coding (RLNC) applies when a large amount of information or many messages are to be disseminated. Instead of routing messages through intermediate nodes, that is, following a classical store-and-forward approach, RLNC mixes messages together by forwarding random linear combinations of messages. The simplicity and topology-obliviousness of this approach makes RLNC particularly interesting for the distributed settings considered in this thesis. Unfortunately the performance of RLNC was not well understood even for the simplest such settings. We introduce a simple yet powerful analysis technique that allows us to prove optimal performance guarantees for all settings considered in the literature and many more that were not analyzable so far. Specifically, we give many new results for RLNC gossip algorithms, RLNC algorithms for dynamic networks, and RLNC with correlated data. We also provide a novel highly efficient distributed implementation of RLNC that achieves these performance guarantees while buffering only a minimal amount of information at intermediate nodes. We then apply our techniques to improve communication primitives in multi-hop radio networks. While radio networks inherently support broadcast communications, e.g., from one node to all surrounding nodes, interference of simultaneous transmissions makes multihop broadcast communication an interesting challenge. We show that, again, randomization holds the key for obtaining simple, efficient and distributed information dissemination protocols. In particular, using random back-off strategies to coordinate access to the shared medium leads to optimal gossip-like communications and applying RLNC achieves the first throughput-optimal multi-message communication primitives. Lastly we apply our probabilistic approach for analyzing simple, distributed propagation protocols in a broader context by studying algorithms for the Lovász Local Lemma. These algorithms find solutions to certain local constraint satisfaction problems by randomly fixing and propagating violations locally. Our two main results show that, firstly, there are also efficient deterministic propagation strategies achieving the same and, secondly, using the random fixing strategy has the advantage of producing not just an arbitrary solution but an approximately uniformly random one. Both results lead to simple, constructions for a many locally consistent structures of interest that were not known to be efficiently constructable before.by Bernhard Haeupler.Ph.D

Direction-reversing Quasi-random Rumor Spreading with Restarts

Doerr and Fouz [\emphAsymptotically Optimal Randomized Rumor Spreading}, ICALP 2011] presented a new quasi-random PUSH algorithm for the rumor spreading problem on complete graphs. Their protocol is the first randomized PUSH protocol with an asymptotically optimal running time. This is achieved by equipping all nodes with the same lists, and by allowing them to do a random restart after encountering an already informed node. Here in this work, we show that the same running time can be achieved if every second random restart is replaced by a reversion of the direction in which the nodes follow their lists. Put differently, our \emph{direction-reversing quasi-random rumor spreading protocol with random restarts achieves the same running time as the hybrid model by employing only (roughly) half the number of random choices

Obiter Dicta

"Stitched together over five years of journaling, Obiter Dicta is a commonplace book of freewheeling explorations representing the transcription of a dozen notebooks, since painstakingly reimagined for publication. Organized after Theodor Adorno’s Minima Moralia, this unschooled exercise in aesthetic thought—gleefully dilettantish, oftentimes dangerously close to the epigrammatic—interrogates an array of subject matter (although inescapably circling back to the curiously resemblant histories of Western visual art and instrumental music) through the lens of drive-by speculation. Erick Verran’s approach to philosophical inquiry follows the brute-force literary technique of Jacques Derrida to exhaustively favor the material grammar of a signifier over hand-me-down meaning, juxtaposing outer semblances with their buried systems and our etched-in-stone intuitions about color and illusion, shape and value, with lessons stolen from seemingly unrelatable disciplines. Interlarded with extracts of Ludwig Wittgenstein but also Wallace Stevens, Cormac McCarthy as well as Roland Barthes, this cache of incidental remarks eschews what’s granular for the biggest picture available, leaving below the hyper-specialized fields of academia for a bird’s-eye view of their crop circles. Obiter Dicta is an unapologetic experiment in intellectual dot-connecting that challenges much long-standing wisdom about everything from illuminated manuscripts to Minecraft and the evolution of European music with lyrical brevity; that is, before jumping to the next topic.

Semantic discovery and reuse of business process patterns

Patterns currently play an important role in modern information systems (IS) development and their use has mainly been restricted to the design and implementation phases of the development lifecycle. Given the increasing significance of business modelling in IS development, patterns have the potential of providing a viable solution for promoting reusability of recurrent generalized models in the very early stages of development. As a statement of research-in-progress this paper focuses on business process patterns and proposes an initial methodological framework for the discovery and reuse of business process patterns within the IS development lifecycle. The framework borrows ideas from the domain engineering literature and proposes the use of semantics to drive both the discovery of patterns as well as their reuse

Recollecting Turbulence: Catastrophe and Sacrifice in the History of My Life by Henry Darger

This study of The History of My Life the 5,086 page autobiographical text by the outsider artist/author Henry Darger, uses non-linear modes of analysis, such as chaos and complexity theory, to explore the meaning of Darger\u27s epic narrative. Beginning with the idea that turbulence, seemingly chaotic, actually comes about as a compensatory restructuring of inadequate or unstable system dynamics, this study goes on to show that, as both influence and effect, turbulence is found at every level of Darger\u27s life and art, both in theme and structure. My Life is a prime example: an extended narrative describing a cataclysmic tornado, in which the text itself manifests turbulent properties of the storm it describes. Darger\u27s particular narrative madness is, in fact, an attempt to put turbulence into service as an alternative system of meaning, in contrast to failed social and religious systems of which he was the product. Henry Darger\u27s work provides us with the challenge of exploring new ways of finding meaning in narrative. This study uses traditional literary criticism coupled with a pattern analysis of redundancy to explore some of Darger\u27s primary themes

With Amusement for All: A History of American Popular Culture since 1830

Popular culture is a central part of everyday life to many Americans. Personalities such as Elvis Presley, Oprah Winfrey, and Michael Jordan are more recognizable to many people than are most elected officials. With Amusement for All is the first comprehensive history of two centuries of mass entertainment in the United States, covering everything from the penny press to Playboy, the NBA to NASCAR, big band to hip hop, and other topics including film, comics, television, sports, dance, and music. Paying careful attention to matters of race, gender, class, technology, economics, and politics, LeRoy Ashby emphasizes the complex ways in which popular culture simultaneously reflects and transforms American culture, revealing that the world of entertainment constantly evolves as it tries to meet the demands of a diverse audience. Trends in popular entertainment often reveal the tensions between competing ideologies, appetites, and values in American society. For example, in the late nineteenth century, Americans embraced “self-made men” such as John D. Rockefeller and Andrew Carnegie: the celebrities of the day were circus tycoons P.T. Barnum and James A. Bailey, Wild West star “Buffalo Bill” Cody, professional baseball organizer Albert Spalding, and prizefighter John L. Sullivan. At the same time, however, several female performers challenged traditional notions of weak, frail Victorian women. Adah Isaacs Menken astonished crowds by wearing tights that made her appear nude while performing dangerous stunts on horseback, and the shows of the voluptuous burlesque group British Blondes often centered on provocative images of female sexual power and dominance. Ashby describes how history and politics frequently influence mainstream entertainment. When Native Americans, blacks, and other non-whites appeared in the nineteenth-century circuses and Wild West shows, it was often to perpetuate demeaning racial stereotypes—crowds jeered Sitting Bull at Cody’s shows. By the early twentieth century, however, black minstrel acts reveled in racial tensions, reinforcing stereotypes while at the same time satirizing them and mocking racist attitudes before a predominantly white audience. Decades later, Red Foxx and Richard Pryor’s profane comedy routines changed American entertainment. The raw ethnic material of Pryor’s short-lived television show led to a series of African-American sitcoms in the 1980s that presented common American experiences—from family life to college life—with black casts. Mainstream entertainment has often co-opted and sanitized fringe amusements in an ongoing process of redefining the cultural center and its boundaries. Social control and respectability vied with the bold, erotic, sensational, and surprising, as entrepreneurs sought to manipulate the vagaries of the market, control shifting public appetites, and capitalize on campaigns to protect public morals. Rock ‘n Roll was one such fringe culture; in the 1950s, Elvis blurred gender norms with his androgynous style and challenged conventions of public decency with his sexually-charged performances. By the end of the 1960s, Bob Dylan introduced the social consciousness of folk music into the rock scene, and The Beatles embraced hippie counter-culture. Don McLean’s 1971 anthem “American Pie” served as an epitaph for rock’s political core, which had been replaced by the spectacle of hard rock acts such as Kiss and Alice Cooper. While Rock ‘n Roll did not lose its ability to shock, in less than three decades it became part of the established order that it had originally sought to challenge. With Amusement for All provides the context to what Americans have done for fun since 1830, showing the reciprocal nature of the relationships between social, political, economic, and cultural forces and the way in which the entertainment world has reflected, refracted, or reinforced the values those forces represent in America. LeRoy Ashby is Regents Professor and Claudius O. and Mary Johnson Distinguished Professor of History at Washington State University. He is the author of several books, including Fighting the Odds: The Life of Senator Frank Church and Endangered Children: Dependency, Neglect, and Abuse in American History. Combines being a remarkably quixotic endeavor with being something of a monumental achievement of scholarship and pure perseverance. --Belles Lettres -- Belles Lettres When regarding this book\u27s comprehensiveness, the richness of its detail, and the strength of its interpretation of the specifics of popular culture, I stand in awe. What an achievement! Majestic! --Benjamin G. Rader, author of Baseball: A History of America\u27s Game This intelligent, energetic book has the ability to appeal to historians and scholars without distancing the general reader. The easy linear narrative is punctuated by songs, comic anecdotes, and rich descriptions that bring each era to life. --Charleston Post and Courier Ashby has given us a fine new book. They say in baseball, \u27it\u27s hard to tell the players without a scorecard.\u27 With Amusement for All will be the new scorecard for anyone interested in the study of popular culture. The book is both comprehensive and smart, a fine combination of surveying the terrain then saying intelligent things about it. Ashby has rendered an invaluable service. --Elliott Gorn, co-author of A Brief History of American Sports American popular culture isn\u27t a distraction from the serious issues of our time. It is inseparable from them. . . . Researches events ranging from Wild West shows to Janet Jackson\u27s wardrobe malfunctions during the 2004 Super Bowl. --Lewiston Tribune No single author has tackled popular culture with so much breadth and depth and managed to strike a balance between the popular and scholarly approaches. Ashby\u27s absorbing and hugely informative study will appeal to a wide audience. Highly recommended. --Library Journal (starred review) I know of no other book that provides the same kind of documented, engaging, and lively narrative about American popular culture as With Amusement for All. --Michael Allen, author of Rodeo Cowboys in the North American Imagination It is not taken for granted that Super Bowls and reality talent shows are discussed around water coolers everywhere the morning after they occur. What should be more common is the use of such entertainment supernovas by historians interested in understanding what makes American culture tick. Thanks to Ashby\u27s fascinating book, this task has become substantially easier. --Pacific Northwest Quarterly The author skilfully quotes appropriate anecdotes and gives us fine, brief descriptions of some of the personalities of the day. . . . Well and fluently written and pleasant to read, and offers a good summary of a whole lot of material about popular culture. --Early Popular Visual Culture Without question, the author...has researched and written a masterpiece. The book is a tour de force in its field and has made popular culture--once thought to be a frivolous area for academic study--a serious field of inquiry. --USA Today LeRoy Ashby draws on the substantial volume of historical scholarship on American popular culture produced since the 1970s to present a survey of impressive breadth on two centuries of American amusements. --Journal of American History “You’ll enjoy this fascinating and massively researched volume on how Americans have amused themselves and how it changed the world.” –WTBF Radio In With Amusement for All, one will find a wide variety of entertainment venues - radio, television, music, sports, movies and the internet; from P.T. Barnum\u27s bunkum to Sheldon Cooper\u27s hokum , it is all here, presented in an informative, entertaining narrative. -- The Past in Review -- The Past in Reviewhttps://uknowledge.uky.edu/upk_american_popular_culture/1017/thumbnail.jp