ACM SIGACT NewsPub Date : 2021-06-17DOI: 10.1145/3471469.3471482
D. Richards
{"title":"Teaching Nondeterminism","authors":"D. Richards","doi":"10.1145/3471469.3471482","DOIUrl":"https://doi.org/10.1145/3471469.3471482","url":null,"abstract":"Nondeterminism is an important topic that is difficult to teach. We give a plan that starts with a new abstraction of nondeterminism. We present language models rst and foremost. The use of pseudo-code augmented by a new construct makes it easier to follow.","PeriodicalId":387985,"journal":{"name":"ACM SIGACT News","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128445002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACM SIGACT NewsPub Date : 2021-06-17DOI: 10.1145/3471469.3471472
Erick Galinkin
{"title":"Review of The Foundations of Computability Theory (Second Edition) by Borut Robič","authors":"Erick Galinkin","doi":"10.1145/3471469.3471472","DOIUrl":"https://doi.org/10.1145/3471469.3471472","url":null,"abstract":"Computability theory forms the foundation for much of theoretical computer science. Many of our great unsolved questions stem from the need to understand what problems can even be solved. The greatest question of computer science, P vs. NP, even sidesteps this entirely, asking instead how efficiently we can find solutions for the problems that we know are solvable. For many students both at the undergraduate and graduate level, a first exposure to computability theory follows a standard sequence on data structures and algorithms and students often marvel at the first results they see on undecidability - how could we possibly prove that we can never solve a problem? This book, in contrast with other books that are often used as first exposures to computability, finite automata, Turing machines, and the like, focuses very specifically on the notion of what is computable and how computability theory, as a science unto itself, fits into the grander scheme. The book is appropriate for advanced undergraduates and beginning graduate students in computer science or mathematics who are interested in theoretical computer science. Robič sidesteps the standard theoretical computer science progression - understanding finite automata and pushdown automata before moving into Turing machines - by setting the stage with Hilbert's program and mathematical prerequisites before introducing the Turing machine absent the usual prerequisites, and then introducing advanced topics often absent in introductory texts. Most chapters are relatively short and contain problem sets, making it appropriate for both a classroom text or for self-study.","PeriodicalId":387985,"journal":{"name":"ACM SIGACT News","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127085583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACM SIGACT NewsPub Date : 2021-06-14DOI: 10.1145/3471469.3471481
P. Veselý
{"title":"Packet Scheduling","authors":"P. Veselý","doi":"10.1145/3471469.3471481","DOIUrl":"https://doi.org/10.1145/3471469.3471481","url":null,"abstract":"Online packet scheduling with deadlines is one of the fundamental models in buffer management. Recently, the author together with Chrobak, Jez, and Sgall (SODA 2019) designed an optimal ϕ-competitive algorithm for this problem, where ϕ ≈1.618 is the golden ratio. In this column, we sketch ideas that led us to the development of this algorithm and outline the concepts in its analysis. We also highlight open questions in packet scheduling.","PeriodicalId":387985,"journal":{"name":"ACM SIGACT News","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128832210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACM SIGACT NewsPub Date : 2021-06-14DOI: 10.1145/3471469.3471471
Frederic Green
{"title":"The Book Review Column","authors":"Frederic Green","doi":"10.1145/3471469.3471471","DOIUrl":"https://doi.org/10.1145/3471469.3471471","url":null,"abstract":"From the ethereal heights of the theory of computability, to the developing eras of computer science, to the sometimes vexing complexities of the present day.","PeriodicalId":387985,"journal":{"name":"ACM SIGACT News","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114774910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACM SIGACT NewsPub Date : 2021-06-14DOI: 10.1145/3471469.3471475
D. Kelley
{"title":"Technical Report Column","authors":"D. Kelley","doi":"10.1145/3471469.3471475","DOIUrl":"https://doi.org/10.1145/3471469.3471475","url":null,"abstract":"Welcome to the Technical Reports Column. If your institution publishes technical reports that you'd like to have included here, please contact me at the email address above.","PeriodicalId":387985,"journal":{"name":"ACM SIGACT News","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121941841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACM SIGACT NewsPub Date : 2021-06-14DOI: 10.1145/3471469.3471476
W. Gasarch
{"title":"Hilbert's Tenth Problem","authors":"W. Gasarch","doi":"10.1145/3471469.3471476","DOIUrl":"https://doi.org/10.1145/3471469.3471476","url":null,"abstract":"This column is a short version of a long version of an article based on a blog. What? I give the complete history.","PeriodicalId":387985,"journal":{"name":"ACM SIGACT News","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133814059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACM SIGACT NewsPub Date : 2021-06-14DOI: 10.1145/3471469.3471484
M. Raynal
{"title":"Distributed Computability","authors":"M. Raynal","doi":"10.1145/3471469.3471484","DOIUrl":"https://doi.org/10.1145/3471469.3471484","url":null,"abstract":"As today Computer Science is more and more (driven) consumed by its applications, it becomes more and more important to know what is and what is not computable. For a long time now, this has been relatively well understood in sequential computing. But today the computing world becomes more and more distributed, and consequently more and more applications are distributed. As a result, it becomes important, or even crucial, to understand what is distributed computing and which are its power and its limits. This article is a step in this direction from an agreement-oriented and fault-tolerance perspective.","PeriodicalId":387985,"journal":{"name":"ACM SIGACT News","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122322891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACM SIGACT NewsPub Date : 2021-06-14DOI: 10.1145/3471469.3471479
Alexander Knop, Shachar Lovett, Sam McGuire, Weiqiang Yuan
{"title":"Guest Column","authors":"Alexander Knop, Shachar Lovett, Sam McGuire, Weiqiang Yuan","doi":"10.1145/3471469.3471479","DOIUrl":"https://doi.org/10.1145/3471469.3471479","url":null,"abstract":"Communication complexity studies the amount of communication necessary to compute a function whose value depends on information distributed among several entities. Yao [Yao79] initiated the study of communication complexity more than 40 years ago, and it has since become a central eld in theoretical computer science with many applications in diverse areas such as data structures, streaming algorithms, property testing, approximation algorithms, coding theory, and machine learning. The textbooks [KN06,RY20] provide excellent overviews of the theory and its applications.","PeriodicalId":387985,"journal":{"name":"ACM SIGACT News","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128210313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACM SIGACT NewsPub Date : 2021-03-16DOI: 10.1145/3457588.3457591
Sarvagya Upadhyay
{"title":"Review of Algorithmic Aspects of Machine Learning By Ankur Moitra","authors":"Sarvagya Upadhyay","doi":"10.1145/3457588.3457591","DOIUrl":"https://doi.org/10.1145/3457588.3457591","url":null,"abstract":"Over the past two decades, machine learning has seen tremendous development in practice. Technological advancement and increased computational resources have enabled several learning algorithms to become quite useful in practice. Although many families of learning algorithms are heuristic in nature, their usefulness cannot be understated. Empirical observations coupled with abundance of new datasets have led to development of novel algorithmic techniques that aim to accomplish a variety of learning tasks efficiently on real-world problems. But what makes these algorithms work on such real-world problems? Clearly, producing correct solutions is one aspect of it. The other aspect is efficiency. While many of these algorithms solve hard problems and cannot be theoretically efficient (under plausible complexity-theoretic assumptions), they seemingly do work on real-world problems. It begets the question: are there conditions under which these algorithms become tractable? Having an answer to this fundamental question sheds light on the power and limitations of these algorithmic techniques. This book focuses on different learning models and problems, and sets out to capture the assumptions that make certain algorithms tractable. The emphasis is on models and algorithmic techniques that make learning an efficient endeavor.","PeriodicalId":387985,"journal":{"name":"ACM SIGACT News","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123214663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ACM SIGACT NewsPub Date : 2021-03-16DOI: 10.1145/3457588.3457603
Stephen A. Fenner
{"title":"Remembrances of Alan","authors":"Stephen A. Fenner","doi":"10.1145/3457588.3457603","DOIUrl":"https://doi.org/10.1145/3457588.3457603","url":null,"abstract":"Alan L. Selman, who profoundly shaped the eld of computational complexity and who sup- ported and encouraged students and colleagues in so many ways, died on January 22, 2021 at the age of 79. On the pages that follow are six remembrances of him and his work from people who knew him well, ranging from the personal to the technical. I'd like to thank them all profusely|Lance Fortnow, Steven Homer, Mitsu Ogihara, Ken Regan, Jin-Yi Cai, Aduri Pavan|for their contribu- tions on such short notice, and I apologize in advance for not reaching out to others, simply for lack of time.","PeriodicalId":387985,"journal":{"name":"ACM SIGACT News","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134232243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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