Protocol combinators for modeling, testing, and execution of distributed systems

Distributed systems are hard to get right, model, test, debug, and teach. Their textbook definitions, typically given in a form of replicated state machines, are concise, yet prone to introducing programming errors if naïvely translated into runnable implementations. In this work, we present Distributed Protocol Combinators (DPC), a declarative programming framework that aims to bridge the gap between specifications and runnable implementations of distributed systems, and facilitate their modeling, testing, and execution. DPC builds on the ideas from the state-of-the art logics for compositional systems verification. The contribution of DPC is a novel family of program-level primitives, which facilitates construction of larger distributed systems from smaller components, streamlining the usage of the most common asynchronous message-passing communication patterns, and providing machinery for testing and user-friendly dynamic verification of systems. This paper describes the main ideas behind the design of the framework and presents its implementation in Haskell. We introduce DPC through a series of characteristic examples and showcase it on a number of distributed protocols from the literature. This paper extends our preceeding conference publication (Andersen & Sergey, 2019a) with an exploration of randomized testing for protocols and their implementations, and an additional case study demonstrating bounded model checking of protocols.

Publication Rate and Evidence-Based Evaluation of Abstracts Presented at the Annual Veterinary Orthopedic Society Conference

Objectives Scientific abstracts are a common method for disseminating new research. There is no information on the publication rate of orthopaedic surgery abstracts presented at the annual Veterinary Orthopedic Society (VOS) Conference. The objectives of this study were to document the publication rate, the publication timeline and the level of evidence (LoE) of abstracts presented at an annual orthopaedic meeting. Study Design All conference abstracts from the 2001 to 2014 annual VOS meeting were reviewed, and final publication was determined through a comprehensive bibliographic search. Results Over 14 conferences, 1,112 scientific abstracts were presented with an overall publication rate of 47%. The majority of abstracts had low LoE scores, and those abstracts were published less timely than ones with higher LoE scores. Once presented, most abstracts took 1 year to be submitted and 2 years to be published. Dog (45%) and ex vivo (19%) studies were the most common. Publication occurred most frequently in Veterinary Surgery (40%), Veterinary and Comparative Orthopaedics and Traumatology (17%) and the American Journal of Veterinary Research (12%). Conclusion The publication rate for abstracts presented at the annual VOS meeting is lower than those from a more generalized veterinary surgery conference. Publication occurs most frequently in a select group of journals, and the subject matter is limited in scope with a focus on dog and ex vivo studies. Overall, most abstracts presented at VOS contain a lower LoE.

Back Matter

The Midwest Public Affairs Conference, Publication License, Submission Information, and Back Cover

Back Matter

The Midwest Public Affairs Conference, Publication License, Submission Information, and Back Cover

Back Matter

The Midwest Public Affairs Conference, Publication License, Submission Information, and Back Cover

Hungarians in Kyiv. Leading figures of history of Hungarian-Ukrainian relations from 9th century to present day

In this review, the author sheds light on the content and concept of the publication entitled Hungarians in Kyiv. Historical Chapters of Hungarian-Ukrainian Relations from the 9th Century to the Present by Stefan-Arpad Madiar. In 2005, in the course of an international scientific conference ‘Ukraine-Hungary: Common Past and Present’ at the Institute of History of Ukraine of the NAS of Ukraine, the main issues and challenges of the history of relations between Ukraine and Hungary were discussed. The participants of the conference concluded an agreement on the establishment of the commission of historians to strengthen scientific cooperation. The review notes that Ukrainian and Hungarian historians should carry on a permanent dialogue on disputable matters related to the historical past of the two nations for obtaining objective knowledge about the relations between Hungary and Ukraine at different historical junctures. The book Hungarians in Kyiv. Historical Chapters of Hungarian-Ukrainian Relations from the 9th Century to the Present is considered as a joint artistic achievement of cooperation among Ukrainian and Hungarian historians. The review also mentions certain aspects of the past relations between Ukraine and Hungary, and the life of Stefan-Arpad Madiar, the main initiator, author, and layout director of the publication. The author stresses that it was Stefan-Arpad Madiar who managed to work on the book structure, select original illustrations, exclusive documentary materials, engage famous scholars and historians to the creation of the book, etc. The book consists of 23 problematically and chronologically arranged chapters and offers a glimpse of unique periods in the history of relations between Ukraine and Hungary, activities of Hungarian diplomatic missions in Kyiv and Ukrainian missions in Budapest, and contains information about Hungarian prisoners of war in post-war Kyiv based on memoirs and archival documents. The author is fully confident that this book will give its readers new knowledge about the history of relations between Ukraine and Hungary, thus facilitating the sense of a more profound understanding between the two nations. Key words: relations between Ukraine and Hungary, scientific conference, publication Hungarians in Kyiv. Historical Chapters of Hungarian-Ukrainian Relations from the 9th Century to the Present, Embassy of Hungary in Ukraine, cooperation between Ukraine and Hungary.

Back Matter

The Midwest Public Affairs Conference, Publication License, Submission Information, and Back Cover

Lessons from the Amazon Picking Challenge: Four Aspects of Building Robotic Systems

We describe the winning entry to the Amazon Picking Challenge 2015. From the experience of building this system and competing, we derive several conclusions: (1) We suggest to characterize robotic system building along four key aspects, each of them spanning a spectrum of solutions - modularity vs. integration, generality vs. assumptions, computation vs. embodiment, and planning vs. feedback. (2) To understand which region of each spectrum most adequately addresses which robotic problem, we must explore the full spectrum of possible approaches. (3) For manipulation problems in unstructured environments, certain regions of each spectrum match the problem most adequately, and should be exploited further. This is supported by the fact that our solution deviated from the majority of the other challenge entries along each of the spectra. This is an abridged version of a conference publication.