@article{18017, abstract = {The conductance of individual 1,4-benzenediamine (BDA)–Au molecular junctions is measured in different solvent environments using a scanning tunneling microscope based point-contact technique. Solvents are found to increase the conductance of these molecular junctions by as much as 50%. Using first principles calculations, we explain this increase by showing that a shift in the Au contact work function is induced by solvents binding to undercoordinated Au sites around the junction. Increasing the Au contact work function reduces the separation between the Au Fermi energy and the highest occupied molecular orbital of BDA in the junction, increasing the measured conductance. We demonstrate that the solvent-induced shift in conductance depends on the affinity of the solvent to Au binding sites and also on the induced dipole (relative to BDA) upon adsorption. Via this mechanism, molecular junction level alignment and transport properties can be statistically altered by solvent molecule binding to the contact surface.}, author = {Fatemi, V. and Kamenetska, M. and Neaton, J. B. and Venkataraman, Latha}, issn = {1530-6992}, journal = {Nano Letters}, number = {5}, pages = {1988--1992}, publisher = {American Chemical Society}, title = {{Environmental control of single-molecule junction transport}}, doi = {10.1021/nl200324e}, volume = {11}, year = {2011}, } @article{18018, abstract = {Controlling electron transport through a single-molecule device is key to the realization of nanoscale electronic components. A design requirement for single molecule electrical devices is that the molecule must be both structurally and electrically connected to the metallic electrodes. Typically, the mechanical and electrical contacts are achieved by the same chemical moiety. In this study, we demonstrate that the structural role may be played by one group (for example, a sulfide) while the electrical role may be played by another (a conjugated chain of C═C π-bonds). We can specify the electrical conductance through the molecule by modulating to which particular site on the oligoene chain the electrode binds. The result is a device that functions as a potentiometer at the single-molecule level.}, author = {Meisner, Jeffrey S. and Kamenetska, Masha and Krikorian, Markrete and Steigerwald, Michael L. and Venkataraman, Latha and Nuckolls, Colin}, issn = {1530-6992}, journal = {Nano Letters}, number = {4}, pages = {1575--1579}, publisher = {American Chemical Society}, title = {{A single-molecule potentiometer}}, doi = {10.1021/nl104411f}, volume = {11}, year = {2011}, } @article{18019, abstract = {We simultaneously measure conductance and force across nanoscale junctions. A new, two-dimensional histogram technique is introduced to statistically extract bond rupture forces from a large data set of individual junction elongation traces. For the case of Au point contacts, we find a rupture force of 1.4 ± 0.2 nN, which is in good agreement with previous measurements. We then study systematic trends for single gold metal−molecule−metal junctions for a series of molecules terminated with amine and pyridine linkers. For all molecules studied, single molecule junctions rupture at the Au−N bond. Selective binding of the linker group allows us to correlate the N−Au bond-rupture force to the molecular backbone. We find that the rupture force ranges from 0.8 nN for 4,4′ bipyridine to 0.5 nN in 1,4 diaminobenzene. These experimental results are in excellent quantitative agreement with density functional theory based adiabatic molecular junction elongation and rupture calculations.}, author = {Frei, Michael and Aradhya, Sriharsha V. and Koentopp, Max and Hybertsen, Mark S. and Venkataraman, Latha}, issn = {1530-6992}, journal = {Nano Letters}, number = {4}, pages = {1518--1523}, publisher = {American Chemical Society}, title = {{Mechanics and chemistry: Single molecule bond rupture forces correlate with molecular backbone structure}}, doi = {10.1021/nl1042903}, volume = {11}, year = {2011}, } @article{18020, abstract = {Understanding electron transport across π−π-stacked systems will help to answer fundamental questions about biochemical redox processes and benefit the design of new materials and molecular devices. Herein we employed the STM break-junction technique to measure the single-molecule conductance of multiple π−π-stacked aromatic rings. We studied electron transport through up to four stacked benzene rings held together in an eclipsed fashion via a paracyclophane scaffold. We found that the strained hydrocarbons studied herein couple directly to gold electrodes during the measurements; hence, we did not require any heteroatom binding groups as electrical contacts. Density functional theory-based calculations suggest that the gold atoms of the electrodes bind to two neighboring carbon atoms of the outermost cyclophane benzene rings in η2 fashion. Our measurements show an exponential decay of the conductance with an increasing number of stacked benzene rings, indicating a nonresonant tunneling mechanism. Furthermore, STM tip−substrate displacement data provide additional evidence that the electrodes bind to the outermost benzene rings of the π−π-stacked molecular wires.}, author = {Schneebeli, Severin T. and Kamenetska, Maria and Cheng, Zhanling and Skouta, Rachid and Friesner, Richard A. and Venkataraman, Latha and Breslow, Ronald}, issn = {1520-5126}, journal = {Journal of the American Chemical Society}, number = {7}, pages = {2136--2139}, publisher = {American Chemical Society}, title = {{Single-molecule conductance through multiple π−π-stacked benzene rings determined with direct electrode-to-benzene ring connections}}, doi = {10.1021/ja111320n}, volume = {133}, year = {2011}, } @article{18021, abstract = {Charge transport across metal–molecule interfaces has an important role in organic electronics1. Typically, chemical link groups such as thiols2 or amines3 are used to bind organic molecules to metal electrodes in single-molecule circuits, with these groups controlling both the physical structure and the electronic coupling at the interface. Direct metal–carbon coupling has been shown through C60, benzene and π-stacked benzene4,5,6,7, but ideally the carbon backbone of the molecule should be covalently bonded to the electrode without intervening link groups. Here, we demonstrate a method to create junctions with such contacts. Trimethyl tin (SnMe3)-terminated polymethylene chains are used to form single-molecule junctions with a break-junction technique2,3. Gold atoms at the electrode displace the SnMe3 linkers, leading to the formation of direct Au–C bonded single-molecule junctions with a conductance that is ∼100 times larger than analogous alkanes with most other terminations. The conductance of these Au–C bonded alkanes decreases exponentially with molecular length, with a decay constant of 0.97 per methylene, consistent with a non-resonant transport mechanism. Control experiments and ab initio calculations show that high conductances are achieved because a covalent Au–C sigma (σ) bond is formed. This offers a new method for making reproducible and highly conducting metal–organic contacts.}, author = {Cheng, Z.-L. and Skouta, R. and Vazquez, H. and Widawsky, J. R. and Schneebeli, S. and Chen, W. and Hybertsen, M. S. and Breslow, R. and Venkataraman, Latha}, issn = {1748-3395}, journal = {Nature Nanotechnology}, number = {6}, pages = {353--357}, publisher = {Springer Nature}, title = {{In situ formation of highly conducting covalent Au–C contacts for single-molecule junctions}}, doi = {10.1038/nnano.2011.66}, volume = {6}, year = {2011}, } @article{1815, abstract = {Many membrane channels and receptors exhibit adaptive, or desensitized, response to a strong sustained input stimulus, often supported by protein activity-dependent inactivation. Adaptive response is thought to be related to various cellular functions such as homeostasis and enlargement of dynamic range by background compensation. Here we study the quantitative relation between adaptive response and background compensation within a modeling framework. We show that any particular type of adaptive response is neither sufficient nor necessary for adaptive enlargement of dynamic range. In particular a precise adaptive response, where system activity is maintained at a constant level at steady state, does not ensure a large dynamic range neither in input signal nor in system output. A general mechanism for input dynamic range enlargement can come about from the activity-dependent modulation of protein responsiveness by multiple biochemical modification, regardless of the type of adaptive response it induces. Therefore hierarchical biochemical processes such as methylation and phosphorylation are natural candidates to induce this property in signaling systems.}, author = {Tamar Friedlander and Brenner, Naama}, journal = {Mathematical Biosciences and Engineering}, number = {2}, pages = {515 -- 526}, publisher = {Arizona State University}, title = {{Adaptive response and enlargement of dynamic range}}, doi = {10.3934/mbe.2011.8.515}, volume = {8}, year = {2011}, } @article{18362, abstract = {Maximally stable component detection is a very popular method for feature analysis in images, mainly due to its low computation cost and high repeatability. With the recent advance of feature-based methods in geometric shape analysis, there is significant interest in finding analogous approaches in the 3D world. In this paper, we formulate a diffusion-geometric framework for stable component detection in non-rigid 3D shapes, which can be used for geometric feature detection and description. A quantitative evaluation of our method on the SHREC’10 feature detection benchmark shows its potential as a source of high-quality features.}, author = {Litman, Roee and Bronstein, Alexander and Bronstein, Michael M.}, issn = {0097-8493}, journal = {Computers & Graphics}, number = {3}, pages = {549--560}, publisher = {Elsevier}, title = {{Diffusion-geometric maximally stable component detection in deformable shapes}}, doi = {10.1016/j.cag.2011.03.011}, volume = {35}, year = {2011}, } @article{18363, abstract = {Natural objects can be subject to various transformations yet still preserve properties that we refer to as invariants. Here, we use definitions of affine-invariant arclength for surfaces in in order to extend the set of existing non-rigid shape analysis tools. We show that by re-defining the surface metric as its equi-affine version, the surface with its modified metric tensor can be treated as a canonical Euclidean object on which most classical Euclidean processing and analysis tools can be applied. The new definition of a metric is used to extend the fast marching method technique for computing geodesic distances on surfaces, where now, the distances are defined with respect to an affine-invariant arclength. Applications of the proposed framework demonstrate its invariance, efficiency, and accuracy in shape analysis.}, author = {Raviv, Dan and Bronstein, Alexander and Bronstein, Michael M. and Kimmel, Ron and Sochen, Nir}, issn = {0097-8493}, journal = {Computers & Graphics}, number = {3}, pages = {692--697}, publisher = {Elsevier}, title = {{Affine-invariant geodesic geometry of deformable 3D shapes}}, doi = {10.1016/j.cag.2011.03.030}, volume = {35}, year = {2011}, } @inproceedings{18377, abstract = {We introduce an (equi-)affine invariant diffusion geometry by which surfaces that go through squeeze and shear transformations can still be properly analyzed. The definition of an affine invariant metric enables us to construct an invariant Laplacian from which local and global geometric structures are extracted. Applications of the proposed framework demonstrate its power in generalizing and enriching the existing set of tools for shape analysis.}, author = {Raviv, Dan and Bronstein, Michael M. and Bronstein, Alexander and Kimmel, Ron and Sochen, Nir}, booktitle = {CVPR 2011}, isbn = {9781457703942}, issn = {1063-6919}, location = {Colorado Springs, CO, United States}, publisher = {IEEE}, title = {{Affine-invariant diffusion geometry for the analysis of deformable 3D shapes}}, doi = {10.1109/cvpr.2011.5995486}, year = {2011}, } @inproceedings{18394, abstract = {In this paper we present a novel approach for fast search of handwritten Arabic word-parts within large lexicons. The algorithm runs through three steps to achieve the required results. First it warps multiple appearances of each word-part in the lexicon for embedding into the same euclidean space. The embedding is done based on the warping path produced by the Dynamic Time Warping (DTW) process while calculating the similarity distance. In the next step, all samples of different word-parts are resampled uniformly to the same size. The kd-tree structure is used to store all shapes representing word parts in the lexicon. Fast approximation of k-nearest neighbors generates a short list of candidates to be presented to the next step. In the third step, the Active-DTW [15] algorithm is used to examine each sample in the short list and give final accurate results. We demonstrate our method on a database of 23,500 images of word-parts extracted from the IFN/ENIT database [6] and 22,000 images collected from 93 writers. Our method achieves a speedup of 5 orders of magnitude over the exact method, at the cost of only a 3.8% reduction in accuracy.}, author = {Saabni, Raid and Bronstein, Alexander}, booktitle = {2011 International Conference on Document Analysis and Recognition}, isbn = {9781457713507}, issn = {2379-2140}, location = {Beijing, China}, publisher = {IEEE}, title = {{Fast key-word searching via embedding and active-DTW}}, doi = {10.1109/icdar.2011.23}, year = {2011}, } @inproceedings{18406, abstract = {Defining a suitable metric is one of the biggest challenges in deformable image fusion from different modalities. In this paper, we propose a novel approach for multi-modal metric learning in the deformable registration framework that consists of embedding data from both modalities into a common metric space whose metric is used to parametrize the similarity. Specifically, we use image representation in the Fourier/Gabor space which introduces invariance to the local pose parameters, and the Hamming metric as the target embedding space, which allows constructing the embedding using boosted learning algorithms. The resulting metric is incorporated into a discrete optimization framework. Very promising results demonstrate the potential of the proposed method.}, author = {Michel, Fabrice and Bronstein, Michael and Bronstein, Alexander and Paragios, Nikos}, booktitle = {2011 IEEE International Symposium on Biomedical Imaging: From Nano to Macro}, isbn = {9781424441280}, issn = {1945-8452}, location = { Chicago, IL, United States}, publisher = {IEEE}, title = {{Boosted metric learning for 3D multi-modal deformable registration}}, doi = {10.1109/isbi.2011.5872619}, year = {2011}, } @article{18411, abstract = {Recent works have shown the use of diffusion geometry for various pattern recognition applications, including nonrigid shape analysis. In this paper, we introduce spectral shape distance as a general framework for distribution-based shape similarity and show that two recent methods for shape similarity due to Rustamov and Mahmoudi and Sapiro are particular cases thereof.}, author = {Bronstein, Michael M and Bronstein, Alexander}, issn = {0162-8828}, journal = {IEEE Transactions on Pattern Analysis and Machine Intelligence}, number = {5}, pages = {1065--1071}, publisher = {Institute of Electrical and Electronics Engineers}, title = {{Shape recognition with spectral distances}}, doi = {10.1109/tpami.2010.210}, volume = {33}, year = {2011}, } @article{18433, abstract = {The computer vision and pattern recognition communities have recently witnessed a surge of feature-based methods in object recognition and image retrieval applications. These methods allow representing images as collections of “visual words” and treat them using text search approaches following the “bag of features” paradigm. In this article, we explore analogous approaches in the 3D world applied to the problem of nonrigid shape retrieval in large databases. Using multiscale diffusion heat kernels as “geometric words,” we construct compact and informative shape descriptors by means of the “bag of features” approach. We also show that considering pairs of “geometric words” (“geometric expressions”) allows creating spatially sensitive bags of features with better discriminative power. Finally, adopting metric learning approaches, we show that shapes can be efficiently represented as binary codes. Our approach achieves state-of-the-art results on the SHREC 2010 large-scale shape retrieval benchmark.}, author = {Bronstein, Alexander and Bronstein, Michael M. and Guibas, Leonidas J. and Ovsjanikov, Maks}, issn = {1557-7368}, journal = {ACM Transactions on Graphics}, number = {1}, pages = {1--20}, publisher = {Association for Computing Machinery}, title = {{Shape google: Geometric words and expressions for invariant shape retrieval}}, doi = {10.1145/1899404.1899405}, volume = {30}, year = {2011}, } @article{22061, abstract = {We consider the defocusing nonlinear wave equation utt − Δu + |u| pu = 0 with spherically-symmetric initial data in the regime 4 d−2 4 d−2 . The principal result is that blowup (or failure to scatter) must be accompanied by blowup of the critical Sobolev norm. An equivalent formulation is that maximal-lifespan solutions with bounded critical Sobolev norm are global and scatter}, author = {Killip, Rowan and Visan, Monica}, issn = {1088-6826}, journal = {Proceedings of the American Mathematical Society}, number = {5}, pages = {1805--1817}, publisher = {American Mathematical Society}, title = {{The radial defocusing energy-supercritical nonlinear wave equation in all space dimensions}}, doi = {10.1090/s0002-9939-2010-10615-9}, volume = {139}, year = {2011}, } @article{3315, abstract = {We consider two-player games played in real time on game structures with clocks where the objectives of players are described using parity conditions. The games are concurrent in that at each turn, both players independently propose a time delay and an action, and the action with the shorter delay is chosen. To prevent a player from winning by blocking time, we restrict each player to play strategies that ensure that the player cannot be responsible for causing a zeno run. First, we present an efficient reduction of these games to turn-based (i.e., not concurrent) finite-state (i.e., untimed) parity games. Our reduction improves the best known complexity for solving timed parity games. Moreover, the rich class of algorithms for classical parity games can now be applied to timed parity games. The states of the resulting game are based on clock regions of the original game, and the state space of the finite game is linear in the size of the region graph. Second, we consider two restricted classes of strategies for the player that represents the controller in a real-time synthesis problem, namely, limit-robust and bounded-robust winning strategies. Using a limit-robust winning strategy, the controller cannot choose an exact real-valued time delay but must allow for some nonzero jitter in each of its actions. If there is a given lower bound on the jitter, then the strategy is bounded-robust winning. We show that exact strategies are more powerful than limit-robust strategies, which are more powerful than bounded-robust winning strategies for any bound. For both kinds of robust strategies, we present efficient reductions to standard timed automaton games. These reductions provide algorithms for the synthesis of robust real-time controllers.}, author = {Chatterjee, Krishnendu and Henzinger, Thomas A and Prabhu, Vinayak}, journal = {Logical Methods in Computer Science}, number = {4}, publisher = {International Federation for Computational Logic}, title = {{Timed parity games: Complexity and robustness}}, doi = {10.2168/LMCS-7(4:8)2011}, volume = {7}, year = {2011}, } @inproceedings{3302, abstract = {Cloud computing aims to give users virtually unlimited pay-per-use computing resources without the burden of managing the underlying infrastructure. We present a new job execution environment Flextic that exploits scal- able static scheduling techniques to provide the user with a flexible pricing model, such as a tradeoff between dif- ferent degrees of execution speed and execution price, and at the same time, reduce scheduling overhead for the cloud provider. We have evaluated a prototype of Flextic on Amazon EC2 and compared it against Hadoop. For various data parallel jobs from machine learning, im- age processing, and gene sequencing that we considered, Flextic has low scheduling overhead and reduces job du- ration by up to 15% compared to Hadoop, a dynamic cloud scheduler.}, author = {Henzinger, Thomas A and Singh, Anmol and Singh, Vasu and Wies, Thomas and Zufferey, Damien}, booktitle = {3rd USENIX Workshop on Hot Topics in Cloud Computing}, location = {Portland, OR, United States}, pages = {1 -- 6}, publisher = {Usenix Association}, title = {{Static scheduling in clouds}}, year = {2011}, } @inproceedings{3356, abstract = {There is recently a significant effort to add quantitative objectives to formal verification and synthesis. We introduce and investigate the extension of temporal logics with quantitative atomic assertions, aiming for a general and flexible framework for quantitative-oriented specifications. In the heart of quantitative objectives lies the accumulation of values along a computation. It is either the accumulated summation, as with the energy objectives, or the accumulated average, as with the mean-payoff objectives. We investigate the extension of temporal logics with the prefix-accumulation assertions Sum(v) ≥ c and Avg(v) ≥ c, where v is a numeric variable of the system, c is a constant rational number, and Sum(v) and Avg(v) denote the accumulated sum and average of the values of v from the beginning of the computation up to the current point of time. We also allow the path-accumulation assertions LimInfAvg(v) ≥ c and LimSupAvg(v) ≥ c, referring to the average value along an entire computation. We study the border of decidability for extensions of various temporal logics. In particular, we show that extending the fragment of CTL that has only the EX, EF, AX, and AG temporal modalities by prefix-accumulation assertions and extending LTL with path-accumulation assertions, result in temporal logics whose model-checking problem is decidable. The extended logics allow to significantly extend the currently known energy and mean-payoff objectives. Moreover, the prefix-accumulation assertions may be refined with "controlled-accumulation", allowing, for example, to specify constraints on the average waiting time between a request and a grant. On the negative side, we show that the fragment we point to is, in a sense, the maximal logic whose extension with prefix-accumulation assertions permits a decidable model-checking procedure. Extending a temporal logic that has the EG or EU modalities, and in particular CTL and LTL, makes the problem undecidable.}, author = {Boker, Udi and Chatterjee, Krishnendu and Henzinger, Thomas A and Kupferman, Orna}, location = {Toronto, Canada}, publisher = {IEEE}, title = {{Temporal specifications with accumulative values}}, doi = {10.1109/LICS.2011.33}, year = {2011}, } @misc{5385, abstract = {There is recently a significant effort to add quantitative objectives to formal verification and synthesis. We introduce and investigate the extension of temporal logics with quantitative atomic assertions, aiming for a general and flexible framework for quantitative-oriented specifications. In the heart of quantitative objectives lies the accumulation of values along a computation. It is either the accumulated summation, as with the energy objectives, or the accumulated average, as with the mean-payoff objectives. We investigate the extension of temporal logics with the prefix-accumulation assertions Sum(v) ≥ c and Avg(v) ≥ c, where v is a numeric variable of the system, c is a constant rational number, and Sum(v) and Avg(v) denote the accumulated sum and average of the values of v from the beginning of the computation up to the current point of time. We also allow the path-accumulation assertions LimInfAvg(v) ≥ c and LimSupAvg(v) ≥ c, referring to the average value along an entire computation. We study the border of decidability for extensions of various temporal logics. In particular, we show that extending the fragment of CTL that has only the EX, EF, AX, and AG temporal modalities by prefix-accumulation assertions and extending LTL with path-accumulation assertions, result in temporal logics whose model-checking problem is decidable. The extended logics allow to significantly extend the currently known energy and mean-payoff objectives. Moreover, the prefix-accumulation assertions may be refined with “controlled-accumulation”, allowing, for example, to specify constraints on the average waiting time between a request and a grant. On the negative side, we show that the fragment we point to is, in a sense, the maximal logic whose extension with prefix-accumulation assertions permits a decidable model-checking procedure. Extending a temporal logic that has the EG or EU modalities, and in particular CTL and LTL, makes the problem undecidable.}, author = {Boker, Udi and Chatterjee, Krishnendu and Henzinger, Thomas A and Kupferman, Orna}, issn = {2664-1690}, pages = {14}, publisher = {IST Austria}, title = {{Temporal specifications with accumulative values}}, doi = {10.15479/AT:IST-2011-0003}, year = {2011}, } @misc{5381, abstract = {In two-player finite-state stochastic games of partial obser- vation on graphs, in every state of the graph, the players simultaneously choose an action, and their joint actions determine a probability distri- bution over the successor states. The game is played for infinitely many rounds and thus the players construct an infinite path in the graph. We consider reachability objectives where the first player tries to ensure a target state to be visited almost-surely (i.e., with probability 1) or pos- itively (i.e., with positive probability), no matter the strategy of the second player. We classify such games according to the information and to the power of randomization available to the players. On the basis of information, the game can be one-sided with either (a) player 1, or (b) player 2 having partial observation (and the other player has perfect observation), or two- sided with (c) both players having partial observation. On the basis of randomization, (a) the players may not be allowed to use randomization (pure strategies), or (b) they may choose a probability distribution over actions but the actual random choice is external and not visible to the player (actions invisible), or (c) they may use full randomization. Our main results for pure strategies are as follows: (1) For one-sided games with player 2 perfect observation we show that (in contrast to full randomized strategies) belief-based (subset-construction based) strate- gies are not sufficient, and present an exponential upper bound on mem- ory both for almost-sure and positive winning strategies; we show that the problem of deciding the existence of almost-sure and positive winning strategies for player 1 is EXPTIME-complete and present symbolic algo- rithms that avoid the explicit exponential construction. (2) For one-sided games with player 1 perfect observation we show that non-elementary memory is both necessary and sufficient for both almost-sure and posi- tive winning strategies. (3) We show that for the general (two-sided) case finite-memory strategies are sufficient for both positive and almost-sure winning, and at least non-elementary memory is required. We establish the equivalence of the almost-sure winning problems for pure strategies and for randomized strategies with actions invisible. Our equivalence re- sult exhibit serious flaws in previous results in the literature: we show a non-elementary memory lower bound for almost-sure winning whereas an exponential upper bound was previously claimed.}, author = {Chatterjee, Krishnendu and Doyen, Laurent}, issn = {2664-1690}, pages = {43}, publisher = {IST Austria}, title = {{Partial-observation stochastic games: How to win when belief fails}}, doi = {10.15479/AT:IST-2011-0007}, year = {2011}, } @article{3353, abstract = {Compositional theories are crucial when designing large and complex systems from smaller components. In this work we propose such a theory for synchronous concurrent systems. Our approach follows so-called interface theories, which use game-theoretic interpretations of composition and refinement. These are appropriate for systems with distinct inputs and outputs, and explicit conditions on inputs that must be enforced during composition. Our interfaces model systems that execute in an infinite sequence of synchronous rounds. At each round, a contract must be satisfied. The contract is simply a relation specifying the set of valid input/output pairs. Interfaces can be composed by parallel, serial or feedback composition. A refinement relation between interfaces is defined, and shown to have two main properties: (1) it is preserved by composition, and (2) it is equivalent to substitutability, namely, the ability to replace an interface by another one in any context. Shared refinement and abstraction operators, corresponding to greatest lower and least upper bounds with respect to refinement, are also defined. Input-complete interfaces, that impose no restrictions on inputs, and deterministic interfaces, that produce a unique output for any legal input, are discussed as special cases, and an interesting duality between the two classes is exposed. A number of illustrative examples are provided, as well as algorithms to compute compositions, check refinement, and so on, for finite-state interfaces.}, author = {Tripakis, Stavros and Lickly, Ben and Henzinger, Thomas A and Lee, Edward}, journal = {ACM Transactions on Programming Languages and Systems}, number = {4}, publisher = {ACM}, title = {{A theory of synchronous relational interfaces}}, doi = {10.1145/1985342.1985345}, volume = {33}, year = {2011}, }