The 37th edition of the ACM SIGMOD-SIGACT-SIGAI Symposium on Principles of Database Systems (PODS) took place from June 11 to June 13, 2018, in Houston, Texas, USA. As in previous years, the symposium was held jointly with the ACM SIGMOD International Conference on Management of Data (SIGMOD). PODS focuses on theoretical aspects of data management systems and techniques, and the co-location with SIGMOD stimulates interaction between theory-oriented and system-oriented research.
{"title":"Database Theory Column Report on PODS 2018","authors":"M. Arenas","doi":"10.1145/3300150.3300162","DOIUrl":"https://doi.org/10.1145/3300150.3300162","url":null,"abstract":"The 37th edition of the ACM SIGMOD-SIGACT-SIGAI Symposium on Principles of Database Systems (PODS) took place from June 11 to June 13, 2018, in Houston, Texas, USA. As in previous years, the symposium was held jointly with the ACM SIGMOD International Conference on Management of Data (SIGMOD). PODS focuses on theoretical aspects of data management systems and techniques, and the co-location with SIGMOD stimulates interaction between theory-oriented and system-oriented research.","PeriodicalId":22106,"journal":{"name":"SIGACT News","volume":"64 1","pages":"55-57"},"PeriodicalIF":0.0,"publicationDate":"2018-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88295458","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}
These are two books that complement each other; they target different audiences, adopt different pedagogy, they even look very different, yet they treat largely overlapping material. In short, they both present material related to networks; not just computer networks, but any kind of networks that may be subsumed under the newly formed discipline of network science. One of the two books intends to provide a broad sweep and provide a high-level understanding of key concepts, presenting the topics in way accessible to an educated layperson. The other book goes into the nuts and bolts of network science, taking us to the realm of rigorous equations, proofs and algorithms.
{"title":"Joint Review of The Power of Networks: Six Principles that Connect our Lives","authors":"P. Louridas","doi":"10.1145/3300150.3300153","DOIUrl":"https://doi.org/10.1145/3300150.3300153","url":null,"abstract":"These are two books that complement each other; they target different audiences, adopt different pedagogy, they even look very different, yet they treat largely overlapping material. In short, they both present material related to networks; not just computer networks, but any kind of networks that may be subsumed under the newly formed discipline of network science. One of the two books intends to provide a broad sweep and provide a high-level understanding of key concepts, presenting the topics in way accessible to an educated layperson. The other book goes into the nuts and bolts of network science, taking us to the realm of rigorous equations, proofs and algorithms.","PeriodicalId":22106,"journal":{"name":"SIGACT News","volume":"30 1","pages":"7-10"},"PeriodicalIF":0.0,"publicationDate":"2018-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73141929","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}
This column is devoted to geometric clustering and covering problems in Rd. As exact solutions for these problems are usually out of reach (unless d = 1), one is forced to deal with approximations. Here we mostly consider online algorithms, as the online setting introduces additional difficulty due to uncertainty about the future. One representative problem is the following (so-called Unit Covering): given a set of n points in Rd, cover the points by balls of unit diameter, so as to minimize the number of balls used.
{"title":"Computational Geometry Column 68","authors":"A. Dumitrescu","doi":"10.1145/3300150.3300161","DOIUrl":"https://doi.org/10.1145/3300150.3300161","url":null,"abstract":"This column is devoted to geometric clustering and covering problems in Rd. As exact solutions for these problems are usually out of reach (unless d = 1), one is forced to deal with approximations. Here we mostly consider online algorithms, as the online setting introduces additional difficulty due to uncertainty about the future. One representative problem is the following (so-called Unit Covering): given a set of n points in Rd, cover the points by balls of unit diameter, so as to minimize the number of balls used.","PeriodicalId":22106,"journal":{"name":"SIGACT News","volume":"44 1","pages":"46-54"},"PeriodicalIF":0.0,"publicationDate":"2018-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75447336","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}
It's great to be back at PODC. I attended this conference religiously through 1992. It's interesting to see what has changed but also what has not changed in 25 years. And I can't think of a happier excuse to be back. All of us know how gratifying it is to see that our work is having impact, and that's what this award signi es. To win an award that carries Dijkstra's name is especially meaningful for me. As a graduate student, I read and reread Dijkstra's work; it changed the way I looked at systems research and the research enterprise. (Bowen will o er some remarks that expand on this theme.) I then had a chance to meet Dijkstra when I served as teaching assistant for a 1-week short course he taught in Santa Cruz. That was the summer following my rst year as an assistant professor at Cornell; my colleague David Gries had gotten me the assistantship. I guess I did OK, because Dijkstra and his wife Ria subsequently invited me to visit their home in Nuenen (The Netherlands) for a week. What a thrill. I subsequently saw Dijkstra at technical meetings and socially at least once a year, until he passed away. So, yes, I have many Dijkstra stories to tell. Catch me after dessert for those. You can read our paper De ning Liveness" (it's only 5 pages!) if you are interested in the technical details. I thought that instead I would talk about how we developed those ideas and where things stand today. I'm always fascinated by the history behind discoveries, and I suspect that I'm not alone in enjoying this academic gossip".
很高兴回到PODC。1992年我一直虔诚地参加这个会议。看看25年来有什么变化,也有什么没有变化,这很有趣。我再也找不到比这更开心的借口了。我们所有人都知道,看到我们的工作产生影响是多么令人欣慰,这就是这个奖项的意义。赢得一个以Dijkstra的名字命名的奖项对我来说意义非凡。作为一名研究生,我反复阅读Dijkstra的作品;它改变了我对系统研究和研究企业的看法。(鲍文将发表一些关于这一主题的评论。)然后我有机会见到Dijkstra,当时我担任他在圣克鲁斯教的为期一周的短期课程的助教。那是我在康奈尔大学担任助理教授第一年之后的那个夏天;我的同事大卫·格雷斯帮我拿到了助教奖学金。我想我做得还可以,因为Dijkstra和他的妻子Ria随后邀请我去他们在纽南(荷兰)的家玩一个星期。太激动了。后来,我每年至少在技术会议和社交场合见到Dijkstra一次,直到他去世。所以,是的,我有很多Dijkstra的故事要讲。吃完甜点再找我。如果你对技术细节感兴趣,你可以阅读我们的论文“De ning Liveness”(只有5页!)。我想我应该谈谈我们是如何发展这些想法的,以及今天的情况。我总是对发现背后的历史着迷,我想我不是唯一一个喜欢这种“学术八卦”的人。
{"title":"History and Context for Defining Liveness: Winner 2018 Edsger W. Dijkstra Prize","authors":"F. Schneider","doi":"10.1145/3300150.3300164","DOIUrl":"https://doi.org/10.1145/3300150.3300164","url":null,"abstract":"It's great to be back at PODC. I attended this conference religiously through 1992. It's interesting to see what has changed but also what has not changed in 25 years. And I can't think of a happier excuse to be back. All of us know how gratifying it is to see that our work is having impact, and that's what this award signi es.\u0000 To win an award that carries Dijkstra's name is especially meaningful for me. As a graduate student, I read and reread Dijkstra's work; it changed the way I looked at systems research and the research enterprise. (Bowen will o er some remarks that expand on this theme.) I then had a chance to meet Dijkstra when I served as teaching assistant for a 1-week short course he taught in Santa Cruz. That was the summer following my rst year as an assistant professor at Cornell; my colleague David Gries had gotten me the assistantship. I guess I did OK, because Dijkstra and his wife Ria subsequently invited me to visit their home in Nuenen (The Netherlands) for a week. What a thrill. I subsequently saw Dijkstra at technical meetings and socially at least once a year, until he passed away. So, yes, I have many Dijkstra stories to tell. Catch me after dessert for those. You can read our paper De ning Liveness\" (it's only 5 pages!) if you are interested in the technical details. I thought that instead I would talk about how we developed those ideas and where things stand today. I'm always fascinated by the history behind discoveries, and I suspect that I'm not alone in enjoying this academic gossip\".","PeriodicalId":22106,"journal":{"name":"SIGACT News","volume":"23 1","pages":"60-63"},"PeriodicalIF":0.0,"publicationDate":"2018-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81569654","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}
The International Colloquium on Structural Information and Communication Complexity (SIROCCO) is devoted to the study of decentralized systems consisting of multiple communicating entities, with a special focus on better understanding how knowledge and communication a ect the feasibility and efficiency of solving tasks in such systems. The conference turned 25 this year, and I am proud to say that I share its birthplace: Ottawa, Canada (unfortunately, 11-year-old Avery did not have a paper to submit to the rst one). Another milestone is that this was the rst SIROCCO to be held in Israel. The venue: a kibbutz called Ma'ale HaHamisha perched high up in the Judean Hills near Jerusalem.
{"title":"SIROCCO 2018 Review","authors":"Avery Miller","doi":"10.1145/3300150.3300166","DOIUrl":"https://doi.org/10.1145/3300150.3300166","url":null,"abstract":"The International Colloquium on Structural Information and Communication Complexity (SIROCCO) is devoted to the study of decentralized systems consisting of multiple communicating entities, with a special focus on better understanding how knowledge and communication a ect the feasibility and efficiency of solving tasks in such systems.\u0000 The conference turned 25 this year, and I am proud to say that I share its birthplace: Ottawa, Canada (unfortunately, 11-year-old Avery did not have a paper to submit to the rst one). Another milestone is that this was the rst SIROCCO to be held in Israel. The venue: a kibbutz called Ma'ale HaHamisha perched high up in the Judean Hills near Jerusalem.","PeriodicalId":22106,"journal":{"name":"SIGACT News","volume":"181 1","pages":"66-82"},"PeriodicalIF":0.0,"publicationDate":"2018-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80260954","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}
The 2018 ACM Symposium on the Principles of Distributed Computing (PODC 2018) was held on July 23-27, at Royal Holloway, University of London, in Egham, UK (see Figure 1). This venue achieved a nice balance between two opposing desirable features of a conference location: being remote enough to encourage conference participants to attend most of the talks, and being central enough to allow for enjoyable tourism. Royal Holloway is only a 15 minute drive from Windsor Castle (see Figure 2), and about an hour away from central London. This allowed conference attendees to enjoy London before and after the conference, but also created a lively atmosphere in the lecture hall and during breaks, as most conference attendees remained in the area.
{"title":"PODC 2018 Review","authors":"N. Ben-David","doi":"10.1145/3300150.3300167","DOIUrl":"https://doi.org/10.1145/3300150.3300167","url":null,"abstract":"The 2018 ACM Symposium on the Principles of Distributed Computing (PODC 2018) was held on July 23-27, at Royal Holloway, University of London, in Egham, UK (see Figure 1). This venue achieved a nice balance between two opposing desirable features of a conference location: being remote enough to encourage conference participants to attend most of the talks, and being central enough to allow for enjoyable tourism. Royal Holloway is only a 15 minute drive from Windsor Castle (see Figure 2), and about an hour away from central London. This allowed conference attendees to enjoy London before and after the conference, but also created a lively atmosphere in the lecture hall and during breaks, as most conference attendees remained in the area.","PeriodicalId":22106,"journal":{"name":"SIGACT News","volume":"1 1","pages":"83-88"},"PeriodicalIF":0.0,"publicationDate":"2018-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89839211","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}
It would be understatement to say that news of this year's Dijkstra award came to me as a surprise. In fact, it put me into a rather profound funk, occasioning unsought re ection on my arguably misspent adulthood. It has been some time since I have done signi cant scienti c research. So, I am quite humbled to be here. I did not really know Dijkstra, but I certainly knew of him. With Fred and David Gries on the faculty, his in uence on the Computer Science Department at Cornell was substantial when I was a graduate student. (I trust it still is.)
{"title":"Edsger W. Dijkstra: The Man Behind the Prize","authors":"B. Alpern","doi":"10.1145/3300150.3300165","DOIUrl":"https://doi.org/10.1145/3300150.3300165","url":null,"abstract":"It would be understatement to say that news of this year's Dijkstra award came to me as a surprise. In fact, it put me into a rather profound funk, occasioning unsought re ection on my arguably misspent adulthood. It has been some time since I have done signi cant scienti c research. So, I am quite humbled to be here. I did not really know Dijkstra, but I certainly knew of him. With Fred and David Gries on the faculty, his in uence on the Computer Science Department at Cornell was substantial when I was a graduate student. (I trust it still is.)","PeriodicalId":22106,"journal":{"name":"SIGACT News","volume":"120 1","pages":"64-65"},"PeriodicalIF":0.0,"publicationDate":"2018-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87847327","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}
The 2018 Donald E. Knuth Prize will be awarded to Johan Håstad of KTH Royal Institute of Technology for his long and sustained record of milestone breakthroughs at the foundations of computer science, with huge impact on many areas including optimization, cryptography, parallel computing, and complexity theory. Håstad's multiple seminal works have not only resolved longstanding deepest problems central to circuit lower bounds, pseudorandom generation, and approximability, but also introduced transformative techniques that have fundamentally influenced much of the subsequent work in these areas.
{"title":"2018 Knuth Prize is Awarded to Johan Håstad","authors":"Shenghua Teng","doi":"10.1145/3289137.3289152","DOIUrl":"https://doi.org/10.1145/3289137.3289152","url":null,"abstract":"The 2018 Donald E. Knuth Prize will be awarded to Johan Håstad of KTH Royal Institute of Technology for his long and sustained record of milestone breakthroughs at the foundations of computer science, with huge impact on many areas including optimization, cryptography, parallel computing, and complexity theory. Håstad's multiple seminal works have not only resolved longstanding deepest problems central to circuit lower bounds, pseudorandom generation, and approximability, but also introduced transformative techniques that have fundamentally influenced much of the subsequent work in these areas.","PeriodicalId":22106,"journal":{"name":"SIGACT News","volume":"29 1","pages":"78-79"},"PeriodicalIF":0.0,"publicationDate":"2018-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89869074","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}
Population protocols have been an active area of distributed computing for over a decade, as they are an abstract model of numerous real-world scenarios from sensor networks to biological computing paradigms. For this column, Dan Alistarh and Rati Gelashvili provide a timely overview of recent results on population protocols, focusing especially on the case when each agent in the system can have more than a constant amount of local memory. Several key building blocks are presented, followed by applications of these primitives, in an accessible way that conveys the excitement of fast-moving developments in the area.
{"title":"Distributed Computing Column 71: Recent Algorithmic Advances in Population Protocols","authors":"J. Welch","doi":"10.1145/3289137.3289149","DOIUrl":"https://doi.org/10.1145/3289137.3289149","url":null,"abstract":"Population protocols have been an active area of distributed computing for over a decade, as they are an abstract model of numerous real-world scenarios from sensor networks to biological computing paradigms. For this column, Dan Alistarh and Rati Gelashvili provide a timely overview of recent results on population protocols, focusing especially on the case when each agent in the system can have more than a constant amount of local memory. Several key building blocks are presented, followed by applications of these primitives, in an accessible way that conveys the excitement of fast-moving developments in the area.","PeriodicalId":22106,"journal":{"name":"SIGACT News","volume":"88 1","pages":"62"},"PeriodicalIF":0.0,"publicationDate":"2018-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89874513","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}
For a number of years we have been investigating the geometric and algebraic properties of a family of discrete sets of points in Euclidean space generated by a simple binary operation: pairwise affine combination by a xed parameter, which we call xed-parameter extrapolation. By varying the parameter and the set of initial points, a large variety of point sets emerge. To our surprise, many of these sets display aperiodic order and share properties of so-called quasicrystals" or quasilattices." Such sets display some ordered crystal-like properties (e.g., generation by a regular set of local rules, such as a nite set of tiles, and possessing a kind of repetitivity), but are aperiodic" in the sense that they have no translational symmetry. The most famous of such systems are Penrose's aperiodic tilings of the plane [16]. Mathematically, a widely accepted way of capturing the idea of aperiodic order is via the notion of Meyer sets, which we de ne later. Our goal is to classify the sets generated by xed-parameter extrapolation in terms of a number of these properties, including but not limited to aperiodicity, uniform discreteness, and relative density. We also seek to determine exactly which parameter values lead to which types of sets.
{"title":"Fixed-Parameter Extrapolation and Aperiodic Order: Open Problems","authors":"Stephen A. Fenner, Frederic Green, S. Homer","doi":"10.1145/3289137.3289145","DOIUrl":"https://doi.org/10.1145/3289137.3289145","url":null,"abstract":"For a number of years we have been investigating the geometric and algebraic properties of a family of discrete sets of points in Euclidean space generated by a simple binary operation: pairwise affine combination by a xed parameter, which we call xed-parameter extrapolation. By varying the parameter and the set of initial points, a large variety of point sets emerge. To our surprise, many of these sets display aperiodic order and share properties of so-called quasicrystals\" or quasilattices.\" Such sets display some ordered crystal-like properties (e.g., generation by a regular set of local rules, such as a nite set of tiles, and possessing a kind of repetitivity), but are aperiodic\" in the sense that they have no translational symmetry. The most famous of such systems are Penrose's aperiodic tilings of the plane [16]. Mathematically, a widely accepted way of capturing the idea of aperiodic order is via the notion of Meyer sets, which we de ne later. Our goal is to classify the sets generated by xed-parameter extrapolation in terms of a number of these properties, including but not limited to aperiodicity, uniform discreteness, and relative density. We also seek to determine exactly which parameter values lead to which types of sets.","PeriodicalId":22106,"journal":{"name":"SIGACT News","volume":"11 1","pages":"35-47"},"PeriodicalIF":0.0,"publicationDate":"2018-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88331862","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}