@inproceedings{1069,
abstract = {The Continuous Skolem Problem asks whether a real-valued function satisfying a linear differen-
tial equation has a zero in a given interval of real numbers. This is a fundamental reachability
problem for continuous linear dynamical systems, such as linear hybrid automata and continuous-
time Markov chains. Decidability of the problem is currently open – indeed decidability is open
even for the sub-problem in which a zero is sought in a bounded interval. In this paper we show
decidability of the bounded problem subject to Schanuel’s Conjecture, a unifying conjecture in
transcendental number theory. We furthermore analyse the unbounded problem in terms of the
frequencies of the differential equation, that is, the imaginary parts of the characteristic roots.
We show that the unbounded problem can be reduced to the bounded problem if there is at most
one rationally linearly independent frequency, or if there are two rationally linearly independent
frequencies and all characteristic roots are simple. We complete the picture by showing that de-
cidability of the unbounded problem in the case of two (or more) rationally linearly independent
frequencies would entail a major new effectiveness result in Diophantine approximation, namely
computability of the Diophantine-approximation types of all real algebraic numbers.},
author = {Chonev, Ventsislav K and Ouaknine, Joël and Worrell, James},
location = {Rome, Italy},
publisher = {Schloss Dagstuhl- Leibniz-Zentrum fur Informatik},
title = {{On the skolem problem for continuous linear dynamical systems}},
doi = {10.4230/LIPIcs.ICALP.2016.100},
volume = {55},
year = {2016},
}
@inproceedings{1070,
abstract = {We present a logic that extends CTL (Computation Tree Logic) with operators that express synchronization properties. A property is synchronized in a system if it holds in all paths of a certain length. The new logic is obtained by using the same path quantifiers and temporal operators as in CTL, but allowing a different order of the quantifiers. This small syntactic variation induces a logic that can express non-regular properties for which known extensions of MSO with equality of path length are undecidable. We show that our variant of CTL is decidable and that the model-checking problem is in Delta_3^P = P^{NP^NP}, and is DP-hard. We analogously consider quantifier exchange in extensions of CTL, and we present operators defined using basic operators of CTL* that express the occurrence of infinitely many synchronization points. We show that the model-checking problem remains in Delta_3^P. The distinguishing power of CTL and of our new logic coincide if the Next operator is allowed in the logics, thus the classical bisimulation quotient can be used for state-space reduction before model checking. },
author = {Chatterjee, Krishnendu and Doyen, Laurent},
location = {Rome, Italy},
publisher = {Schloss Dagstuhl- Leibniz-Zentrum fur Informatik},
title = {{Computation tree logic for synchronization properties}},
doi = {10.4230/LIPIcs.ICALP.2016.98},
volume = {55},
year = {2016},
}
@inproceedings{1071,
abstract = {We consider data-structures for answering reachability and distance queries on constant-treewidth graphs with n nodes, on the standard RAM computational model with wordsize W=Theta(log n). Our first contribution is a data-structure that after O(n) preprocessing time, allows (1) pair reachability queries in O(1) time; and (2) single-source reachability queries in O(n/log n) time. This is (asymptotically) optimal and is faster than DFS/BFS when answering more than a constant number of single-source queries. The data-structure uses at all times O(n) space. Our second contribution is a space-time tradeoff data-structure for distance queries. For any epsilon in [1/2,1], we provide a data-structure with polynomial preprocessing time that allows pair queries in O(n^{1-\epsilon} alpha(n)) time, where alpha is the inverse of the Ackermann function, and at all times uses O(n^epsilon) space. The input graph G is not considered in the space complexity. },
author = {Chatterjee, Krishnendu and Ibsen-Jensen, Rasmus and Pavlogiannis, Andreas},
location = {Aarhus, Denmark},
publisher = {Schloss Dagstuhl- Leibniz-Zentrum fur Informatik},
title = {{Optimal reachability and a space time tradeoff for distance queries in constant treewidth graphs}},
doi = {10.4230/LIPIcs.ESA.2016.28},
volume = {57},
year = {2016},
}
@article{1081,
abstract = {The asymmetric localization of proteins in the plasma membrane domains of eukaryotic cells is a fundamental manifestation of cell polarity that is central to multicellular organization and developmental patterning. In plants, the mechanisms underlying the polar localization of cargo proteins are still largely unknown and appear to be fundamentally distinct from those operating in mammals. Here, we present a systematic, quantitative comparative analysis of the polar delivery and subcellular localization of proteins that characterize distinct polar plasma membrane domains in plant cells. The combination of microscopic analyses and computational modeling revealed a mechanistic framework common to diverse polar cargos and underlying the establishment and maintenance of apical, basal, and lateral polar domains in plant cells. This mechanism depends on the polar secretion, constitutive endocytic recycling, and restricted lateral diffusion of cargos within the plasma membrane. Moreover, our observations suggest that polar cargo distribution involves the individual protein potential to form clusters within the plasma membrane and interact with the extracellular matrix. Our observations provide insights into the shared cellular mechanisms of polar cargo delivery and polarity maintenance in plant cells.},
author = {Łangowski, Łukasz and Wabnik, Krzysztof T and Li, Hongjiang and Vanneste, Steffen and Naramoto, Satoshi and Tanaka, Hirokazu and Friml, Jirí},
journal = {Cell Discovery},
publisher = {Nature Publishing Group},
title = {{Cellular mechanisms for cargo delivery and polarity maintenance at different polar domains in plant cells}},
doi = {10.1038/celldisc.2016.18},
volume = {2},
year = {2016},
}
@inproceedings{1082,
abstract = {In many applications, it is desirable to extract only the relevant aspects of data. A principled way to do this is the information bottleneck (IB) method, where one seeks a code that maximises information about a relevance variable, Y, while constraining the information encoded about the original data, X. Unfortunately however, the IB method is computationally demanding when data are high-dimensional and/or non-gaussian. Here we propose an approximate variational scheme for maximising a lower bound on the IB objective, analogous to variational EM. Using this method, we derive an IB algorithm to recover features that are both relevant and sparse. Finally, we demonstrate how kernelised versions of the algorithm can be used to address a broad range of problems with non-linear relation between X and Y.},
author = {Chalk, Matthew J and Marre, Olivier and Tkacik, Gasper},
location = {Barcelona, Spain},
pages = {1965--1973},
publisher = {Neural Information Processing Systems},
title = {{Relevant sparse codes with variational information bottleneck}},
volume = {29},
year = {2016},
}