@article{723, abstract = {Escaping local optima is one of the major obstacles to function optimisation. Using the metaphor of a fitness landscape, local optima correspond to hills separated by fitness valleys that have to be overcome. We define a class of fitness valleys of tunable difficulty by considering their length, representing the Hamming path between the two optima and their depth, the drop in fitness. For this function class we present a runtime comparison between stochastic search algorithms using different search strategies. The (1+1) EA is a simple and well-studied evolutionary algorithm that has to jump across the valley to a point of higher fitness because it does not accept worsening moves (elitism). In contrast, the Metropolis algorithm and the Strong Selection Weak Mutation (SSWM) algorithm, a famous process in population genetics, are both able to cross the fitness valley by accepting worsening moves. We show that the runtime of the (1+1) EA depends critically on the length of the valley while the runtimes of the non-elitist algorithms depend crucially on the depth of the valley. Moreover, we show that both SSWM and Metropolis can also efficiently optimise a rugged function consisting of consecutive valleys.}, author = {Oliveto, Pietro and Paixao, Tiago and Pérez Heredia, Jorge and Sudholt, Dirk and Trubenova, Barbora}, journal = {Algorithmica}, number = {5}, pages = {1604 -- 1633}, publisher = {Springer}, title = {{How to escape local optima in black box optimisation when non elitism outperforms elitism}}, doi = {10.1007/s00453-017-0369-2}, volume = {80}, year = {2018}, } @article{321, abstract = {The twelve papers in this special section focus on learning systems with shared information for computer vision and multimedia communication analysis. In the real world, a realistic setting for computer vision or multimedia recognition problems is that we have some classes containing lots of training data and many classes containing a small amount of training data. Therefore, how to use frequent classes to help learning rare classes for which it is harder to collect the training data is an open question. Learning with shared information is an emerging topic in machine learning, computer vision and multimedia analysis. There are different levels of components that can be shared during concept modeling and machine learning stages, such as sharing generic object parts, sharing attributes, sharing transformations, sharing regularization parameters and sharing training examples, etc. Regarding the specific methods, multi-task learning, transfer learning and deep learning can be seen as using different strategies to share information. These learning with shared information methods are very effective in solving real-world large-scale problems.}, author = {Darrell, Trevor and Lampert, Christoph and Sebe, Nico and Wu, Ying and Yan, Yan}, journal = {IEEE Transactions on Pattern Analysis and Machine Intelligence}, number = {5}, pages = {1029 -- 1031}, publisher = {IEEE}, title = {{Guest editors' introduction to the special section on learning with Shared information for computer vision and multimedia analysis}}, doi = {10.1109/TPAMI.2018.2804998}, volume = {40}, year = {2018}, } @misc{9841, abstract = {Around 150 million years ago, eusocial termites evolved from within the cockroaches, 50 million years before eusocial Hymenoptera, such as bees and ants, appeared. Here, we report the 2-Gb genome of the German cockroach, Blattella germanica, and the 1.3-Gb genome of the drywood termite Cryptotermes secundus. We show evolutionary signatures of termite eusociality by comparing the genomes and transcriptomes of three termites and the cockroach against the background of 16 other eusocial and non-eusocial insects. Dramatic adaptive changes in genes underlying the production and perception of pheromones confirm the importance of chemical communication in the termites. These are accompanied by major changes in gene regulation and the molecular evolution of caste determination. Many of these results parallel molecular mechanisms of eusocial evolution in Hymenoptera. However, the specific solutions are remarkably different, thus revealing a striking case of convergence in one of the major evolutionary transitions in biological complexity.}, author = {Harrison, Mark C. and Jongepier, Evelien and Robertson, Hugh M. and Arning, Nicolas and Bitard-Feildel, Tristan and Chao, Hsu and Childers, Christopher P. and Dinh, Huyen and Doddapaneni, Harshavardhan and Dugan, Shannon and Gowin, Johannes and Greiner, Carolin and Han, Yi and Hu, Haofu and Hughes, Daniel S. T. and Huylmans, Ann K and Kemena, Carsten and Kremer, Lukas P. M. and Lee, Sandra L. and Lopez-Ezquerra, Alberto and Mallet, Ludovic and Monroy-Kuhn, Jose M. and Moser, Annabell and Murali, Shwetha C. and Muzny, Donna M. and Otani, Saria and Piulachs, Maria-Dolors and Poelchau, Monica and Qu, Jiaxin and Schaub, Florentine and Wada-Katsumata, Ayako and Worley, Kim C. and Xie, Qiaolin and Ylla, Guillem and Poulsen, Michael and Gibbs, Richard A. and Schal, Coby and Richards, Stephen and Belles, Xavier and Korb, Judith and Bornberg-Bauer, Erich}, publisher = {Dryad}, title = {{Data from: Hemimetabolous genomes reveal molecular basis of termite eusociality}}, doi = {10.5061/dryad.51d4r}, year = {2018}, } @inproceedings{397, abstract = {Concurrent sets with range query operations are highly desirable in applications such as in-memory databases. However, few set implementations offer range queries. Known techniques for augmenting data structures with range queries (or operations that can be used to build range queries) have numerous problems that limit their usefulness. For example, they impose high overhead or rely heavily on garbage collection. In this work, we show how to augment data structures with highly efficient range queries, without relying on garbage collection. We identify a property of epoch-based memory reclamation algorithms that makes them ideal for implementing range queries, and produce three algorithms, which use locks, transactional memory and lock-free techniques, respectively. Our algorithms are applicable to more data structures than previous work, and are shown to be highly efficient on a large scale Intel system. }, author = {Arbel Raviv, Maya and Brown, Trevor A}, isbn = {978-1-4503-4982-6}, location = {Vienna, Austria}, number = {1}, pages = {14 -- 27}, publisher = {ACM}, title = {{Harnessing epoch-based reclamation for efficient range queries}}, doi = {10.1145/3178487.3178489}, volume = {53}, year = {2018}, } @article{32, abstract = {The functional role of AMPA receptor (AMPAR)-mediated synaptic signaling between neurons and oligodendrocyte precursor cells (OPCs) remains enigmatic. We modified the properties of AMPARs at axon-OPC synapses in the mouse corpus callosum in vivo during the peak of myelination by targeting the GluA2 subunit. Expression of the unedited (Ca2+ permeable) or the pore-dead GluA2 subunit of AMPARs triggered proliferation of OPCs and reduced their differentiation into oligodendrocytes. Expression of the cytoplasmic C-terminal (GluA2(813-862)) of the GluA2 subunit (C-tail), a modification designed to affect the interaction between GluA2 and AMPAR-binding proteins and to perturb trafficking of GluA2-containing AMPARs, decreased the differentiation of OPCs without affecting their proliferation. These findings suggest that ionotropic and non-ionotropic properties of AMPARs in OPCs, as well as specific aspects of AMPAR-mediated signaling at axon-OPC synapses in the mouse corpus callosum, are important for balancing the response of OPCs to proliferation and differentiation cues. In the brain, oligodendrocyte precursor cells (OPCs) receive glutamatergic AMPA-receptor-mediated synaptic input from neurons. Chen et al. show that modifying AMPA-receptor properties at axon-OPC synapses alters proliferation and differentiation of OPCs. This expands the traditional view of synaptic transmission by suggesting neurons also use synapses to modulate behavior of glia.}, author = {Chen, Ting and Kula, Bartosz and Nagy, Balint and Barzan, Ruxandra and Gall, Andrea and Ehrlich, Ingrid and Kukley, Maria}, journal = {Cell Reports}, number = {4}, pages = {852 -- 861.e7}, publisher = {Elsevier}, title = {{In Vivo regulation of Oligodendrocyte processor cell proliferation and differentiation by the AMPA-receptor Subunit GluA2}}, doi = {10.1016/j.celrep.2018.09.066}, volume = {25}, year = {2018}, } @article{5672, abstract = {The release of IgM is the first line of an antibody response and precedes the generation of high affinity IgG in germinal centers. Once secreted by freshly activated plasmablasts, IgM is released into the efferent lymph of reactive lymph nodes as early as 3 d after immunization. As pentameric IgM has an enormous size of 1,000 kD, its diffusibility is low, and one might wonder how it can pass through the densely lymphocyte-packed environment of a lymph node parenchyma in order to reach its exit. In this issue of JEM, Thierry et al. show that, in order to reach the blood stream, IgM molecules take a specific micro-anatomical route via lymph node conduits.}, author = {Reversat, Anne and Sixt, Michael K}, issn = {00221007}, journal = {Journal of Experimental Medicine}, number = {12}, pages = {2959--2961}, publisher = {Rockefeller University Press}, title = {{IgM's exit route}}, doi = {10.1084/jem.20181934}, volume = {215}, year = {2018}, } @article{398, abstract = {Objective: To report long-term results after Pipeline Embolization Device (PED) implantation, characterize complex and standard aneurysms comprehensively, and introduce a modified flow disruption scale. Methods: We retrospectively reviewed a consecutive series of 40 patients harboring 59 aneurysms treated with 54 PEDs. Aneurysm complexity was assessed using our proposed classification. Immediate angiographic results were analyzed using previously published grading scales and our novel flow disruption scale. Results: According to our new definition, 46 (78%) aneurysms were classified as complex. Most PED interventions were performed in the paraophthalmic and cavernous internal carotid artery segments. Excellent neurologic outcome (modified Rankin Scale 0 and 1) was observed in 94% of patients. Our data showed low permanent procedure-related mortality (0%) and morbidity (3%) rates. Long-term angiographic follow-up showed complete occlusion in 81% and near-total obliteration in a further 14%. Complete obliteration after deployment of a single PED was achieved in all standard aneurysms with 1-year follow-up. Our new scale was an independent predictor of aneurysm occlusion in a multivariable analysis. All aneurysms with a high flow disruption grade showed complete occlusion at follow-up regardless of PED number or aneurysm complexity. Conclusions: Treatment with the PED should be recognized as a primary management strategy for a highly selected cohort with predominantly complex intracranial aneurysms. We further show that a priori assessment of aneurysm complexity and our new postinterventional angiographic flow disruption scale predict occlusion probability and may help to determine the adequate number of per-aneurysm devices.}, author = {Dodier, Philippe and Frischer, Josa and Wang, Wei and Auzinger, Thomas and Mallouhi, Ammar and Serles, Wolfgang and Gruber, Andreas and Knosp, Engelbert and Bavinzski, Gerhard}, journal = {World Neurosurgery}, pages = {e568--e578}, publisher = {Elsevier}, title = {{Immediate flow disruption as a prognostic factor after flow diverter treatment long term experience with the pipeline embolization device}}, doi = {10.1016/j.wneu.2018.02.096}, volume = {13}, year = {2018}, } @article{458, abstract = {We consider congruences of straight lines in a plane with the combinatorics of the square grid, with all elementary quadrilaterals possessing an incircle. It is shown that all the vertices of such nets (we call them incircular or IC-nets) lie on confocal conics. Our main new results are on checkerboard IC-nets in the plane. These are congruences of straight lines in the plane with the combinatorics of the square grid, combinatorially colored as a checkerboard, such that all black coordinate quadrilaterals possess inscribed circles. We show how this larger class of IC-nets appears quite naturally in Laguerre geometry of oriented planes and spheres and leads to new remarkable incidence theorems. Most of our results are valid in hyperbolic and spherical geometries as well. We present also generalizations in spaces of higher dimension, called checkerboard IS-nets. The construction of these nets is based on a new 9 inspheres incidence theorem.}, author = {Akopyan, Arseniy and Bobenko, Alexander}, journal = {Transactions of the American Mathematical Society}, number = {4}, pages = {2825 -- 2854}, publisher = {American Mathematical Society}, title = {{Incircular nets and confocal conics}}, doi = {10.1090/tran/7292}, volume = {370}, year = {2018}, } @article{426, abstract = {Sperm cells are the most morphologically diverse cells across animal taxa. Within species, sperm and ejaculate traits have been suggested to vary with the male's competitive environment, e.g., level of sperm competition, female mating status and quality, and also with male age, body mass, physiological condition, and resource availability. Most previous studies have based their conclusions on the analysis of only one or a few ejaculates per male without investigating differences among the ejaculates of the same individual. This masks potential ejaculate-specific traits. Here, we provide data on the length, quantity, and viability of sperm ejaculated by wingless males of the ant Cardiocondyla obscurior. Males of this ant species are relatively long-lived and can mate with large numbers of female sexuals throughout their lives. We analyzed all ejaculates across the individuals' lifespan and manipulated the availability of mating partners. Our study shows that both the number and size of sperm cells transferred during copulations differ among individuals and also among ejaculates of the same male. Sperm quality does not decrease with male age, but the variation in sperm number between ejaculates indicates that males need considerable time to replenish their sperm supplies. Producing many ejaculates in a short time appears to be traded-off against male longevity rather than sperm quality.}, author = {Metzler, Sina and Schrempf, Alexandra and Heinze, Jürgen}, journal = {Journal of Insect Physiology}, pages = {284--290}, publisher = {Elsevier}, title = {{Individual- and ejaculate-specific sperm traits in ant males}}, doi = {10.1016/j.jinsphys.2017.12.003}, volume = {107}, year = {2018}, } @inproceedings{5788, abstract = {In two-player games on graphs, the players move a token through a graph to produce an infinite path, which determines the winner or payoff of the game. Such games are central in formal verification since they model the interaction between a non-terminating system and its environment. We study bidding games in which the players bid for the right to move the token. Two bidding rules have been defined. In Richman bidding, in each round, the players simultaneously submit bids, and the higher bidder moves the token and pays the other player. Poorman bidding is similar except that the winner of the bidding pays the “bank” rather than the other player. While poorman reachability games have been studied before, we present, for the first time, results on infinite-duration poorman games. A central quantity in these games is the ratio between the two players’ initial budgets. The questions we study concern a necessary and sufficient ratio with which a player can achieve a goal. For reachability objectives, such threshold ratios are known to exist for both bidding rules. We show that the properties of poorman reachability games extend to complex qualitative objectives such as parity, similarly to the Richman case. Our most interesting results concern quantitative poorman games, namely poorman mean-payoff games, where we construct optimal strategies depending on the initial ratio, by showing a connection with random-turn based games. The connection in itself is interesting, because it does not hold for reachability poorman games. We also solve the complexity problems that arise in poorman bidding games.}, author = {Avni, Guy and Henzinger, Thomas A and Ibsen-Jensen, Rasmus}, isbn = {9783030046118}, issn = {03029743}, location = {Oxford, UK}, pages = {21--36}, publisher = {Springer}, title = {{Infinite-duration poorman-bidding games}}, doi = {10.1007/978-3-030-04612-5_2}, volume = {11316}, year = {2018}, } @article{150, abstract = {A short, 14-amino-acid segment called SP1, located in the Gag structural protein1, has a critical role during the formation of the HIV-1 virus particle. During virus assembly, the SP1 peptide and seven preceding residues fold into a six-helix bundle, which holds together the Gag hexamer and facilitates the formation of a curved immature hexagonal lattice underneath the viral membrane2,3. Upon completion of assembly and budding, proteolytic cleavage of Gag leads to virus maturation, in which the immature lattice is broken down; the liberated CA domain of Gag then re-assembles into the mature conical capsid that encloses the viral genome and associated enzymes. Folding and proteolysis of the six-helix bundle are crucial rate-limiting steps of both Gag assembly and disassembly, and the six-helix bundle is an established target of HIV-1 inhibitors4,5. Here, using a combination of structural and functional analyses, we show that inositol hexakisphosphate (InsP6, also known as IP6) facilitates the formation of the six-helix bundle and assembly of the immature HIV-1 Gag lattice. IP6 makes ionic contacts with two rings of lysine residues at the centre of the Gag hexamer. Proteolytic cleavage then unmasks an alternative binding site, where IP6 interaction promotes the assembly of the mature capsid lattice. These studies identify IP6 as a naturally occurring small molecule that promotes both assembly and maturation of HIV-1.}, author = {Dick, Robert and Zadrozny, Kaneil K and Xu, Chaoyi and Schur, Florian and Lyddon, Terri D and Ricana, Clifton L and Wagner, Jonathan M and Perilla, Juan R and Ganser, Pornillos Barbie K and Johnson, Marc C and Pornillos, Owen and Vogt, Volker}, issn = {1476-4687}, journal = {Nature}, number = {7719}, pages = {509–512}, publisher = {Nature Publishing Group}, title = {{Inositol phosphates are assembly co-factors for HIV-1}}, doi = {10.1038/s41586-018-0396-4}, volume = {560}, year = {2018}, } @article{303, abstract = {The theory of tropical series, that we develop here, firstly appeared in the study of the growth of pluriharmonic functions. Motivated by waves in sandpile models we introduce a dynamic on the set of tropical series, and it is experimentally observed that this dynamic obeys a power law. So, this paper serves as a compilation of results we need for other articles and also introduces several objects interesting by themselves.}, author = {Kalinin, Nikita and Shkolnikov, Mikhail}, journal = {Discrete and Continuous Dynamical Systems- Series A}, number = {6}, pages = {2827 -- 2849}, publisher = {AIMS}, title = {{Introduction to tropical series and wave dynamic on them}}, doi = {10.3934/dcds.2018120}, volume = {38}, year = {2018}, } @inproceedings{14202, abstract = {Approximating a probability density in a tractable manner is a central task in Bayesian statistics. Variational Inference (VI) is a popular technique that achieves tractability by choosing a relatively simple variational family. Borrowing ideas from the classic boosting framework, recent approaches attempt to \emph{boost} VI by replacing the selection of a single density with a greedily constructed mixture of densities. In order to guarantee convergence, previous works impose stringent assumptions that require significant effort for practitioners. Specifically, they require a custom implementation of the greedy step (called the LMO) for every probabilistic model with respect to an unnatural variational family of truncated distributions. Our work fixes these issues with novel theoretical and algorithmic insights. On the theoretical side, we show that boosting VI satisfies a relaxed smoothness assumption which is sufficient for the convergence of the functional Frank-Wolfe (FW) algorithm. Furthermore, we rephrase the LMO problem and propose to maximize the Residual ELBO (RELBO) which replaces the standard ELBO optimization in VI. These theoretical enhancements allow for black box implementation of the boosting subroutine. Finally, we present a stopping criterion drawn from the duality gap in the classic FW analyses and exhaustive experiments to illustrate the usefulness of our theoretical and algorithmic contributions.}, author = {Locatello, Francesco and Dresdner, Gideon and Khanna, Rajiv and Valera, Isabel and Rätsch, Gunnar}, booktitle = {Advances in Neural Information Processing Systems}, isbn = {9781510884472}, issn = {1049-5258}, location = {Montreal, Canada}, publisher = {Neural Information Processing Systems Foundation}, title = {{Boosting black box variational inference}}, volume = {31}, year = {2018}, } @inproceedings{14201, abstract = {Variational inference is a popular technique to approximate a possibly intractable Bayesian posterior with a more tractable one. Recently, boosting variational inference has been proposed as a new paradigm to approximate the posterior by a mixture of densities by greedily adding components to the mixture. However, as is the case with many other variational inference algorithms, its theoretical properties have not been studied. In the present work, we study the convergence properties of this approach from a modern optimization viewpoint by establishing connections to the classic Frank-Wolfe algorithm. Our analyses yields novel theoretical insights regarding the sufficient conditions for convergence, explicit rates, and algorithmic simplifications. Since a lot of focus in previous works for variational inference has been on tractability, our work is especially important as a much needed attempt to bridge the gap between probabilistic models and their corresponding theoretical properties.}, author = {Locatello, Francesco and Khanna, Rajiv and Ghosh, Joydeep and Rätsch, Gunnar}, booktitle = {Proceedings of the 21st International Conference on Artificial Intelligence and Statistics}, location = {Playa Blanca, Lanzarote}, pages = {464--472}, publisher = {ML Research Press}, title = {{Boosting variational inference: An optimization perspective}}, volume = {84}, year = {2018}, } @inproceedings{14198, abstract = {High-dimensional time series are common in many domains. Since human cognition is not optimized to work well in high-dimensional spaces, these areas could benefit from interpretable low-dimensional representations. However, most representation learning algorithms for time series data are difficult to interpret. This is due to non-intuitive mappings from data features to salient properties of the representation and non-smoothness over time. To address this problem, we propose a new representation learning framework building on ideas from interpretable discrete dimensionality reduction and deep generative modeling. This framework allows us to learn discrete representations of time series, which give rise to smooth and interpretable embeddings with superior clustering performance. We introduce a new way to overcome the non-differentiability in discrete representation learning and present a gradient-based version of the traditional self-organizing map algorithm that is more performant than the original. Furthermore, to allow for a probabilistic interpretation of our method, we integrate a Markov model in the representation space. This model uncovers the temporal transition structure, improves clustering performance even further and provides additional explanatory insights as well as a natural representation of uncertainty. We evaluate our model in terms of clustering performance and interpretability on static (Fashion-)MNIST data, a time series of linearly interpolated (Fashion-)MNIST images, a chaotic Lorenz attractor system with two macro states, as well as on a challenging real world medical time series application on the eICU data set. Our learned representations compare favorably with competitor methods and facilitate downstream tasks on the real world data.}, author = {Fortuin, Vincent and Hüser, Matthias and Locatello, Francesco and Strathmann, Heiko and Rätsch, Gunnar}, booktitle = {International Conference on Learning Representations}, location = {New Orleans, LA, United States}, title = {{SOM-VAE: Interpretable discrete representation learning on time series}}, year = {2018}, } @inproceedings{14203, abstract = {We propose a conditional gradient framework for a composite convex minimization template with broad applications. Our approach combines smoothing and homotopy techniques under the CGM framework, and provably achieves the optimal O(1/k−−√) convergence rate. We demonstrate that the same rate holds if the linear subproblems are solved approximately with additive or multiplicative error. In contrast with the relevant work, we are able to characterize the convergence when the non-smooth term is an indicator function. Specific applications of our framework include the non-smooth minimization, semidefinite programming, and minimization with linear inclusion constraints over a compact domain. Numerical evidence demonstrates the benefits of our framework.}, author = {Yurtsever, Alp and Fercoq, Olivier and Locatello, Francesco and Cevher, Volkan}, booktitle = {Proceedings of the 35th International Conference on Machine Learning}, location = {Stockholm, Sweden}, pages = {5727--5736}, publisher = {ML Research Press}, title = {{A conditional gradient framework for composite convex minimization with applications to semidefinite programming}}, volume = {80}, year = {2018}, } @article{282, abstract = {Adaptive introgression is common in nature and can be driven by selection acting on multiple, linked genes. We explore the effects of polygenic selection on introgression under the infinitesimal model with linkage. This model assumes that the introgressing block has an effectively infinite number of genes, each with an infinitesimal effect on the trait under selection. The block is assumed to introgress under directional selection within a native population that is genetically homogeneous. We use individual-based simulations and a branching process approximation to compute various statistics of the introgressing block, and explore how these depend on parameters such as the map length and initial trait value associated with the introgressing block, the genetic variability along the block, and the strength of selection. Our results show that the introgression dynamics of a block under infinitesimal selection is qualitatively different from the dynamics of neutral introgression. We also find that in the long run, surviving descendant blocks are likely to have intermediate lengths, and clarify how the length is shaped by the interplay between linkage and infinitesimal selection. Our results suggest that it may be difficult to distinguish introgression of single loci from that of genomic blocks with multiple, tightly linked and weakly selected loci.}, author = {Sachdeva, Himani and Barton, Nicholas H}, journal = {Genetics}, number = {4}, pages = {1279 -- 1303}, publisher = {Genetics Society of America}, title = {{Introgression of a block of genome under infinitesimal selection}}, doi = {10.1534/genetics.118.301018}, volume = {209}, year = {2018}, } @inproceedings{108, abstract = {Universal hashing found a lot of applications in computer science. In cryptography the most important fact about universal families is the so called Leftover Hash Lemma, proved by Impagliazzo, Levin and Luby. In the language of modern cryptography it states that almost universal families are good extractors. In this work we provide a somewhat surprising characterization in the opposite direction. Namely, every extractor with sufficiently good parameters yields a universal family on a noticeable fraction of its inputs. Our proof technique is based on tools from extremal graph theory applied to the \'collision graph\' induced by the extractor, and may be of independent interest. We discuss possible applications to the theory of randomness extractors and non-malleable codes.}, author = {Obremski, Marciej and Skorski, Maciej}, location = {Vail, CO, USA}, publisher = {IEEE}, title = {{Inverted leftover hash lemma}}, doi = {10.1109/ISIT.2018.8437654}, volume = {2018}, year = {2018}, } @inproceedings{14204, abstract = {Two popular examples of first-order optimization methods over linear spaces are coordinate descent and matching pursuit algorithms, with their randomized variants. While the former targets the optimization by moving along coordinates, the latter considers a generalized notion of directions. Exploiting the connection between the two algorithms, we present a unified analysis of both, providing affine invariant sublinear O(1/t) rates on smooth objectives and linear convergence on strongly convex objectives. As a byproduct of our affine invariant analysis of matching pursuit, our rates for steepest coordinate descent are the tightest known. Furthermore, we show the first accelerated convergence rate O(1/t2) for matching pursuit and steepest coordinate descent on convex objectives.}, author = {Locatello, Francesco and Raj, Anant and Karimireddy, Sai Praneeth and Rätsch, Gunnar and Schölkopf, Bernhard and Stich, Sebastian U. and Jaggi, Martin}, booktitle = {Proceedings of the 35th International Conference on Machine Learning}, pages = {3198--3207}, publisher = {ML Research Press}, title = {{On matching pursuit and coordinate descent}}, volume = {80}, year = {2018}, } @inproceedings{160, abstract = {We present layered concurrent programs, a compact and expressive notation for specifying refinement proofs of concurrent programs. A layered concurrent program specifies a sequence of connected concurrent programs, from most concrete to most abstract, such that common parts of different programs are written exactly once. These programs are expressed in the ordinary syntax of imperative concurrent programs using gated atomic actions, sequencing, choice, and (recursive) procedure calls. Each concurrent program is automatically extracted from the layered program. We reduce refinement to the safety of a sequence of concurrent checker programs, one each to justify the connection between every two consecutive concurrent programs. These checker programs are also automatically extracted from the layered program. Layered concurrent programs have been implemented in the CIVL verifier which has been successfully used for the verification of several complex concurrent programs.}, author = {Kragl, Bernhard and Qadeer, Shaz}, location = {Oxford, UK}, pages = {79 -- 102}, publisher = {Springer}, title = {{Layered Concurrent Programs}}, doi = {10.1007/978-3-319-96145-3_5}, volume = {10981}, year = {2018}, }