Florent Jacquemard - Academia.edu (original) (raw)

Papers by Florent Jacquemard

Le projet LETITBE (PHC Amadeus 2015) a pour objectif l'application au développement de systèm... more Le projet LETITBE (PHC Amadeus 2015) a pour objectif l'application au développement de systèmes musicaux interactifs de paradigmes et outils formels pour les systèmes embarqués critiques temps-réels. Il s'agit d'un projet de recherche pluridisciplinaire, chacun des partenaires étant spécialiste d'un des deux thèmes de recherche, et exploratoire, ces approches formelles étant traditionnellement plutôt réservée aux systèmes critiques (avionique, transports, etc)

HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci-entific ... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et a ̀ la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Nous presentons un systeme pour la transcription rythmique integre dans l'environnement de co... more Nous presentons un systeme pour la transcription rythmique integre dans l'environnement de composition assistee par ordinateur OpenMusic. La transcription rythmique consiste a traduire une suite d'evenements dates vers une representation pulsee et structuree liee a la notation musicale traditionnelle. Notre systeme privilegie les interactions avec l'utilisateur afin de trouver un equilibre satisfaisant entre differents criteres, en particulier la precision de la transcription et la lisibilite des partitions produites. Ce systeme s'appuie sur une approche uniforme, utilisant des representations hierarchiques de la notation de durees sous forme d'arbres de rythmes, et des algorithmes efficaces pour l'enumeration paresseuse de solutions de transcription. Sa mise en oeuvre se fait via une interface dediee permettant l'exploration de l'espace des solutions, leur visualisation et leur edition locale, avec une attention particuliere portee sur le traitement ...

Interactive music systems are dynamic real-time systems which combine control and signal processi... more Interactive music systems are dynamic real-time systems which combine control and signal processing based on an audio graph. They are often used on platforms where there are no reliable and precise real-time guarantees. Here, we present a method of optimizing audio graphs and finding a compromise between audio quality and gain in execution time by downsampling parts of the graph. We present models of quality and execution time and we evaluate the models and our optimization algorithm experimentally .

We present a procedure for checking sufficient completeness for conditional and constrained term ... more We present a procedure for checking sufficient completeness for conditional and constrained term rewriting systems containing axioms for constructors which may be constrained (by e.g. equalities, disequalities, ordering, membership...). Such axioms allow to specify complex data structures like e.g. sets, sorted lists or powerlists. Our approach is integrated in a framework for inductive theorem proving based on tree grammars with constraints, a formalism which permits an exact representation of languages of ground constructor terms in normal form. The key technique used in the procedure is a generalized form of narrowing where, given a term, instead of unifying it with left members of rewrite rules, we instantiate it, at selected variables, following the productions of a constrained tree grammar, and test whether it can be rewritten. Our procedure is sound and complete and has been successfully applied to several examples, yielding very natural proofs and, in case of negative answer, a counter example suggesting how to complete the specification. Moreover, it is a decision procedure when the TRS is unconditional but constrained, for a large class of constrained constructor axioms.

Human musicians have since long developed methods and formalisms for ensemble authoring and real-... more Human musicians have since long developed methods and formalisms for ensemble authoring and real-time coordination and synchronization of their actions. Bringing such capabilities to computers and providing them with the ability to take part in musical interactions with human musicians, poses interesting challenges for authoring of time and interaction and real-time coordination that we address in this paper in the context of Mixed Music and the Antescofo project.

Science of Computer Programming, 2016

The role of an Interactive Music System (IMS) is to accompany musicians during live performances,... more The role of an Interactive Music System (IMS) is to accompany musicians during live performances, acting like a real musician. It must react in realtime to audio signals from musicians, according to a timed high-level requirement called mixed score, written in a domain specific language. Such goals imply strong requirements of temporal reliability and robustness to unforeseen errors in input, yet not much addressed by the computer music community. We present the application of Model-Based Testing techniques and tools to a state-of-the-art IMS, including in particular: offline and on-thefly approaches for the generation of relevant input data for testing (including timing values), with coverage criteria, the computation of the corresponding expected output, according to the semantics of a given mixed score, the black-box execution of the test data on the System Under Test and the production of a verdict. Our method is based on formal models in a dedicated intermediate representation, compiled directly from mixed scores (high-level requirements), and either passed, to the model-checker Uppaal (after conversion to Timed Automata) in the offline approach, or executed by a virtual machine in the online approach. Our fully automatic framework has been applied to real mixed scores used in concerts and the results obtained have permitted to identify bugs in the target IMS.

We propose a compact presentation of languages of preferred rhythm notations as formal grammars. ... more We propose a compact presentation of languages of preferred rhythm notations as formal grammars. It is based on a standard structure of rhythm trees capturing a wide range of rhythms in Western notation. As an application, we then describe a dynamic programming algorithm for the lazy enumeration of equivalent rhythm notations (i.e. notations defining the same durations), from the simplest to the most complex. This procedure, based on the notion of rhythm grammars has been implemented and may be useful in the context of automated music transcription and computer-assistance to composition.

We present a tool for the computation of the differences between two XML music score files and th... more We present a tool for the computation of the differences between two XML music score files and the intuitive visualization of those differences on the two scores side-to-side. Our goal is to implement for music scores a utility similar to the Unix diff command for text files. Its purpose is to identify differences between two score files which are relatively similar (typically two versions of the same file), corresponding to the intuitive notion of difference. The comparison is performed at the granularity level of bars (bars are here the analagous, for scores, of lines of text files), using a Longest Common Subsequence (LCS) algorithm, and, in a second step, at the granularity level of notes or chords (the analoguous of characters in text files). The later operation involves the computation of dedicated edit-distances between strings and trees, based on an abstract model of score content use for disambiguating the content for XML score formats and also decoupling our approach from ...

Nous presentons les problematiques temps reel de l’accompagnement musical automatique vu comme un... more Nous presentons les problematiques temps reel de l’accompagnement musical automatique vu comme un systeme reactif. Nous introduisons un modele de datation prenant en compte les differentes echelles de temps specifiques a la musique, et nous proposons plusieurs strategies de synchronisation et de rattrapage d’erreurs effectivement utilisees dans diverses compositions musicales.

Nous proposons une representation des elements de gravure musicale ayant trait au rythme – figure... more Nous proposons une representation des elements de gravure musicale ayant trait au rythme – figures de notes, tuplets, ligatures, etc. – sous la forme d’arbres. Cette modelisation permet de lever les ambiguites et redondances contenues dans les differents encodages de partitions numeriques, qui sont des sources d’incoherences majeures.Le modele est developpe theoriquement, puis nous presentons son integration dans des procedures de verification d’encodages. Il est egalement montre que l’on peut l’utiliser pour des tâches de generation de partitions.

We present a tree-based symbolic representation of rhythm notation suitable for processing with p... more We present a tree-based symbolic representation of rhythm notation suitable for processing with purely syntactic theoretical tools such as term rewriting systems or tree automata. Then we propose an equational theory, defined as a set of rewrite rules for transforming these representations. This theory is complete in the sense that from a given rhythm notation the rules permit to generate all notations of equivalent durations. It can be used to explore the space of Using complementary tree automata formalisms, one can restrict the search space according to notations preferences regarding e.g. metre or other user defined syntactic constraints.

In traditional western music notation, the durations of notes are expressed hier-archically by re... more In traditional western music notation, the durations of notes are expressed hier-archically by recursive subdivisions. This led naturally to a tree representation of melodies widespread in systems for assistance to music authoring. We will see how term rewriting techniques can be applied to computer music problems, in particular to the problem of rhythm quantization: the transcription of a sequence of dates (real time values) into a music score. Besides the question of rhythm representation, an interesting problem in this context is the design and concise description of large rewrite rule sets and decision problems for these descriptions.

Information and Computation, 2020

We study edit distances between strings, based on operations such as character substitutions, ins... more We study edit distances between strings, based on operations such as character substitutions, insertions, deletions and additionally consolidations and fragmentations. The two latter operations transform a sequence of characters into one character and viceversa. They correspond to the compression and expansion in Dynamic Time-Warping algorithms for speech recognition and are also used for the formal analysis of written music. We show that such edit distances are not computable in general, and propose weighted automata constructions to compute an edit distance taking into account both consolidations and deletions, or both fragmentations and insertions. Assuming that the operation ruleset has a constant size, these constructions are polynomial into the lengths of the involved strings. We finally show that the optimal weight of sequences made of consolidations chained with fragmentations, in that order, is computable for arbitrary rulesets, and not computable for some rulesets when we reverse the order of fragmentations and consolidations.

Logical Methods in Computer Science, 2016

A data tree is an unranked ordered tree where each node carries a label from a finite alphabet an... more A data tree is an unranked ordered tree where each node carries a label from a finite alphabet and a datum from some infinite domain. We consider the two variable first order logic FO 2 (<, +1, ∼) over data trees. Here +1 refers to the child and the next sibling relations while < refers to the descendant and following sibling relations. Moreover, ∼ is a binary predicate testing data equality. We exhibit an automata model, denoted DTA # , that is more expressive than FO 2 (<, +1, ∼) but such that emptiness of DTA # and satisfiability of FO 2 (<, +1, ∼) are inter-reducible. This is proved via a model of counter tree automata, denoted EBVASS, that extends Branching Vector Addition Systems with States (BVASS) with extra features for merging counters. We show that, as decision problems, reachability for EBVASS, satisfiability of FO 2 (<, +1, ∼) and emptiness of DTA # are equivalent.

Science of Computer Programming, 2016

Information and Computation, 2020

Logical Methods in Computer Science, 2016