Academic literature on the topic 'Two-way transducers'

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Journal articles on the topic "Two-way transducers"

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Wang, Yulei, Jingya Tao, Feifei Guo, Shiyang Li, Xingyi Huang, Jie Dong, and Wenwu Cao. "Magnesium Alloy Matching Layer for High-Performance Transducer Applications." Sensors 18, no. 12 (December 14, 2018): 4424. http://dx.doi.org/10.3390/s18124424.

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In this paper, we report the use of magnesium alloy (AZ31B) as the matching material for PZT-5H ultrasonic transducers. The AZ31B has an acoustic impedance of 10.3 MRayl, which provides a good acoustic impedance match for PZT-5H ultrasonic transducers in water medium based on the double matching layer theory. Two PZT-5H transducers with different center frequencies were designed and fabricated using the AZ31B. The respective center frequencies of the two fabricated transducers were 4.6 MHz and 9.25 MHz. The 4.6 MHz transducer exhibits a −6 dB bandwidth of 79% and two-way insertion loss of −11.11 dB. The 9.25 MHz transducer also shows good performance: −6 dB bandwidth of 71% and two-way insertion loss of −14.43 dB. The properties of the two transducers are superior to those of transducers using a composite matching layer, indicating that the magnesium alloy may be a promising alternative for high-performance transducers.
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Baudru, Nicolas, and Pierre-Alain Reynier. "From Two-Way Transducers to Regular Function Expressions." International Journal of Foundations of Computer Science 31, no. 06 (September 2020): 843–73. http://dx.doi.org/10.1142/s0129054120410087.

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Transducers constitute a fundamental extension of automata. The class of regular word functions has recently emerged as an important class of word-to-word functions, characterized by means of (functional, or unambiguous, or deterministic) two-way transducers, copyless streaming string transducers, and MSO-definable graph transformations. A fundamental result in language theory is Kleene’s Theorem, relating finite state automata and regular expressions. Recently, a set of regular function expressions has been introduced and used to prove a similar result for regular word functions, by showing its equivalence with copyless streaming string transducers. In this paper, we propose a direct, simplified and effective translation from unambiguous two-way transducers to regular function expressions extending the Brzozowski and McCluskey algorithm. In addition, our approach allows us to derive a subset of regular function expressions characterizing the (strict) subclass of functional sweeping transducers.
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Sklyar, Rostyslav. "A CNTFET-Based Nanowired Induction Two-Way Transducers." ISRN Nanotechnology 2012 (May 14, 2012): 1–9. http://dx.doi.org/10.5402/2012/102783.

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A complex of the induction magnetic field two-way nanotransducers of the different physical values for both the external and implantable interfaces in a wide range of arrays are summarized. Implementation of the nanowires allows reliable transducing of the biosignals' partials and bringing of carbon nanotubes into circuits leading to examination of the superconducting transition. Novel sensors are based on the induction magnetic field principle, which causes their interaction with an ambient EM field. Mathematical description of both the signal and mediums defines space embracing of the relevant interfacing devices. As a result, a wide range of the nano-bio-transducers allow both delivering the variety of ionized biosignals and interface the bioEM signals with further stages of electronic systems. The space coverage and transducing values properties of the state-of-the-art magnetic interfaces are summarized, and directions for their future development are deduced.
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Gurari, Eitan M. "Two-way counter machines and finite-state transducers†." International Journal of Computer Mathematics 17, no. 3-4 (January 1985): 229–35. http://dx.doi.org/10.1080/00207168508803465.

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Choffrut, Christian. "Sequences of words defined by two-way transducers." Theoretical Computer Science 658 (January 2017): 85–96. http://dx.doi.org/10.1016/j.tcs.2016.05.004.

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Engelfriet, Joost, and Hendrik Jan Hoogeboom. "MSO definable string transductions and two-way finite-state transducers." ACM Transactions on Computational Logic 2, no. 2 (April 2001): 216–54. http://dx.doi.org/10.1145/371316.371512.

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Engelfriet, Joost. "Two-way pebble transducers for partial functions and their composition." Acta Informatica 52, no. 7-8 (March 4, 2015): 559–71. http://dx.doi.org/10.1007/s00236-015-0224-3.

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Ibarra, Oscar H., and Hsu-Chun Yen. "On the containment and equivalence problems for two-way transducers." Theoretical Computer Science 429 (April 2012): 155–63. http://dx.doi.org/10.1016/j.tcs.2011.12.034.

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Vágvölgyi, Sándor. "Top-down tree transducers with two-way tree walking look-ahead." Theoretical Computer Science 93, no. 1 (February 1992): 43–74. http://dx.doi.org/10.1016/0304-3975(92)90211-w.

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Yang, Zhi Nian, Yuan Zhang, and Yang Lei. "Fire Test on Two-Way Slab with Two Edges Clamped and Two Edges Simply Supported." Applied Mechanics and Materials 744-746 (March 2015): 148–51. http://dx.doi.org/10.4028/www.scientific.net/amm.744-746.148.

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This paper describes the results of a fire test conducted on two-way slab with two edges clamped and two edges simply supported. The details of support condition, arrangement of reinforcement, position of displacement transducers and thermocouple trees are described. The experimental results such as the temperature distributions within the slab, vertical deflections and horizontal displacements are presented. The experimental results show that the temperature distribution along the slab depth was nonlinear and the temperature gradients in the slab were large. Main cracks near the clamped edges occurred on the top surface of the slab. It is shown that two-way slab with two edges clamped and two edges simply supported has good fire resistance.
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Dissertations / Theses on the topic "Two-way transducers"

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Guillon, B. "Two-wayness: Automata and Transducers." Doctoral thesis, Università degli Studi di Milano, 2016. http://hdl.handle.net/2434/385609.

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This PhD is about two natural extensions of Finite Automata (FA): the 2-way fa (2FA) and the 2-way transducers (2T). It is well known that 2FA s are computably equivalent to FAs, even in their nondeterministic (2nfa) variant. However, in the field of descriptional complexity, some questions remain. Raised by Sakoda and Sipser in 1978, the question of the cost of the simulation of 2NFA by 2DFA (the deterministic variant of 2FA) is still open. In this manuscript, we give an answer in a restricted case in which the nondeterministic choices of the simulated 2NFA may occur at the boundaries of the input tape only (2ONFA). We show that every 2ONFA can be simulated by a 2DFA of subexponential (but superpolynomial) size. Under the assumptions L=NL, this cost is reduced to the polynomial level. Moreover, we prove that the complementation and the simulation by a halting 2ONFA is polynomial. We also consider the anologous simulations for alternating devices. Providing a one-way write-only output tape to FAs leads to the notion of transducer. Contrary to the case of finite automata which are acceptor, 2-way transducers strictly extends the computational power of 1-way one, even in the case where both the input and output alphabets are unary. Though 1-way transducers enjoy nice properties and characterizations (algebraic, logical, etc. . . ), 2-way variants are less known, especially the nondeterministic case. In this area, this manuscript gives a new contribution: an algebraic characterization of the relations accepted by two-way transducers when both the input and output alphabets are unary. Actually, it can be reformulated as follows: each unary two-way transducer is equivalent to a sweeping (and even rotating) transducer. We also show that the assumptions made on the size of the alphabets are required, that is, sweeping transducers weakens the 2-way transducers whenever at least one of the alphabet is non-unary. On the path, we discuss on the computational power of some algebraic operations on word relations, introduced in the aim of describing the behavior of 2-way transducers or, more generally, of 2-way weighted automata. In particular, the mirror operation, consisting in reversing the input word in order to describe a right to left scan, draws our attention. Finally, we study another kind of operations, more adapted for binary word relations: the composition. We consider the transitive closure of relations. When the relation belongs to some very restricted sub-family of rational relations, we are able to compute its transitive closure and we set its complexity. This quickly becomes uncomputable when higher classes are considered.
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Guillon, Bruno. "Two-wayness : automata and transducers." Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCC339.

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Cette thèse porte sur deux extensions naturelles des Automates Finis (FA) : les automates finis bidirectionnels (2FA) et les transducteurs bidirectionnels (2T). Il est bien connu que les 2FA sont calculatoirement équivalents aux FA, même dans leur version non déterministe (2NFA). Cependant, dans le domaine de la complexité descriptionnelle, certaines questions demeurent. Posée par Sakoda et Sipser en 1978, la question du coût de la simulation d'un 2NFA par 2DFA (D pour déterministe) est encore inconnue. Dans cette thèse, je traite cette question dans un cas restreint où les choix non déterministes effectués par le 2NFA ne peuvent avoir lieu qu'au bord du mot d'entrée d'entrée (2ONFA). Les transducteurs classiques (unidirectionnels) sont bien connus et jouissent de caractérisations fortes (relations rationnelles, logique). Cependant leur version bidirectionnelle (2T) est assez méconnue, spécialement dans le cas non déterministe. Dans ce domaine,ma thèse apporte une contribution nouvelle : une caractérisation algébrique des relations acceptées lorsque les alphabets d'entrée et de sortie sont unaires. Celle-ci peut s'exprimer differemment : les 2T unaires sont équivalents au 2T boustrophédons. Je montre également que les hypothèses fortes faites sur les alphabets sont nécessaires. L étude des relations sur les mots et de leur clôture transitive est un autre aspect abordé dans ma thèse
This PhD is about two natural extensions of Finite Automata (FA): the 2-way fa (2FA) and the 2-way transducers (2T). It is well known that 2FA s are computably equivalent to FAs, even in their nondeterministic (2nfa) variant. However, in the field of descriptional complexity, some questions remain. Raised by Sakoda and Sipser in 1978, the question of the cost of the simulation of 2NFA by 2DFA (the deterministic variant of 2FA) is still open. In this manuscript, we give an answer in a restricted case in which the nondeterministic choices of the simulated 2NFA may occur at the boundaries of the input tape only (2ONFA). We show that every 2ONFA can be simulated by a 2DFA of subexponential (but superpolynomial) size. Under the assumptions L=NL, this cost is reduced to the polynomial level. Moreover, we prove that the complementation and the simulation by a halting 2ONFA is polynomial. We also consider the anologous simulations for alternating devices. Providing a one-way write-only output tape to FAs leads to the notion of transducer. Contrary to the case of finite automata which are acceptor, 2-way transducers strictly extends the computational power of 1-way one, even in the case where both the input and output alphabets are unary. Though 1-way transducers enjoy nice properties and characterizations (algebraic, logical, etc. . . ), 2-way variants are less known, especially the nondeterministic case. In this area, this manuscript gives a new contribution: an algebraic characterization of the relations accepted by two-way transducers when both the input and output alphabets are unary. Actually, it can be reformulated as follows: each unary two-way transducer is equivalent to a sweeping (and even rotating) transducer. We also show that the assumptions made on the size of the alphabets are required, that is, sweeping transducers weakens the 2-way transducers whenever at least one of the alphabet is non-unary. On the path, we discuss on the computational power of some algebraic operations on word relations, introduced in the aim of describing the behavior of 2-way transducers or, more generally, of 2-way weighted automata. In particular, the mirror operation, consisting in reversing the input word in order to describe a right to left scan, draws our attention. Finally, we study another kind of operations, more adapted for binary word relations: the composition. We consider the transitive closure of relations. When the relation belongs to some very restricted sub-family of rational relations, we are able to compute its transitive closure and we set its complexity. This quickly becomes uncomputable when higher classes are considered
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Baschenis, Félix. "Minimizing resources for regular word transductions." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0810/document.

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Cette thèse a eu pour objectif d'étudier des questions naturelles de définissabilité autour des transducteurs bidirectionnels.Il est bien connu que les transducteurs bidirectionnels définissent une plus grande classe de transductions que celles des transducteurs unidirectionnels. La première question que nous avons étudiée est donc de décider si un transducteur bidirectionnel est définissable par un transducteur unidirectionnel. Il a été montré en 2013 que cette question est décidable pour des transducteurs fonctionnels (nous montrons aussi en paralèlle que cette question devient indécidable si les transducteurs ne sont plus fonctionnels) mais la complexité de la procédure de décision était non-élémentaire.Nous proposons une caractérisation de la "définissabilité par transducteur unidirectionnel" décidable en espace doublement exponentiel. Cette caractérisation est effective en ce sens qu'elle produit en temps triplement exponentiel le transducteur équivalent. De plus, nous avons étudié ce problème aussi pour les transducteurs "sweeping", pour lesquels la procédure de décision et la construction du transducteur équivalent requièrent une exponentielle de moins. Comme nous avons par ailleurs montré qu'il existe des familles de fonctions réalisables de façon unidirectionnelle avec au minimum deux sauts exponentiels, notre procédure est optimale dans le cas "sweeping".Le fait d'avoir particulièrement étudié les transducteurs"sweeping" nous a poussé à étudier d'autres questions dedéfinissabilité~: est-ce qu'un transducteur donné estréalisable par un transducteur sweeping ? Et par un transducteursweeping réalisant au maximum k passages ? Nous montrons que cesquestions sont décidables avec les mêmes complexitésobtenues précédemment. Comme nous avons montré qu'ilexiste une borne sur le nombre de passages nécéssaires pourréaliser avec un transducteur sweeping une transductiondonnée, cela nous permet aussi de minimiser le nombre de passages d'untransducteur sweeping.Enfin nous avons cherché à caractériser la classe destransductions sweeping dans d'autres modèles de transductions,les Streaming String Transducers (SST) et lestransductions MSO. Cela a en autres permis, en établissant unecorrespondance entre le nombre de passages des transducteurssweeping et le nombre de registres d'une sous-classe de SST, deminimiser le nombre de registres pour une classe intéressantede SST. Dans l'ensemble, notre travail a permis de couvrir l'ensembledes relations entre ces modèles, et les questions dedéfinissabilité qui se posent naturellement
The goal of this thesis was to study definability questionsabout finite-state transducers and in particular two-waytransducers. It is known that two-way transducers cover a larger classof transductions than one-way transducers. Then the first question wetackled is the one-way definability problem: is it possible torealize a given two-way transduction by a one-way transducer? Thisproblem was shown to be decidable for functionaltransducers (we also show as a side result that one-way definability becomes undecidable for non-functional transducers) but the decision procedure had non-elementary complexity.We proposed a characterization of one-way definability thatallows us to decide it in double-exponential space, and provide anequivalent one-way transducer of triple-exponential size. We firststudied this question for a restricted class, namely sweepingtransducers, for which the decision procedure and the construction ofthe one-way transducer take one less exponential. For suchtransducers, our procedure is optimal in the sense that we have shownthat there exists a family of functions that are one-way definable andfor which an equivalent one-way transducer requires doubly exponentialsize.The study of sweeping transducers raised other definability questions: Is a given transducer equivalent to some sweeping transducer? And to some sweeping transducer that performs at most k passes? We showed that those questions are decidable and the decision procedure, as well as the equivalent transducer, have the same complexity as in the one-way case. Moreover, as we have shown that there exists a bound on the number of passes required to realize a transduction by a sweeping transducer, we managed to obtain a procedure to minimize the number of passes of a sweeping transducer.Finally we tried to characterize sweeping transducers in other models for regular transductions such as Streaming String transducers (SST) and MSO transductions. As we obtained an equivalence between the number of passes of a sweeping transducer and the number of registers of the equivalent SST we provided a minimization procedure for the number of registers of a large class of SST's. To conclude, our work allowed us to provide a good overall understanding of the definability questions between the models for regular transductions and in particular regarding the resources, whether it is the number of passes (and of course one-way definability is crucial in that aspect) or the number of registers
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Li, Junhong Li. "Pier Streamlining as a Bridge Local Scour Countermeasure and the Underlying Scour Mechanism." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1518565785864439.

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Book chapters on the topic "Two-way transducers"

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Bose, Sougata, S. N. Krishna, Anca Muscholl, and Gabriele Puppis. "One-way Resynchronizability of Word Transducers." In Lecture Notes in Computer Science, 124–43. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-71995-1_7.

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AbstractThe origin semantics for transducers was proposed in 2014, and it led to various characterizations and decidability results that are in contrast with the classical semantics. In this paper we add a further decidability result for characterizing transducers that are close to one-way transducers in the origin semantics. We show that it is decidable whether a non-deterministic two-way word transducer can be resynchronized by a bounded, regular resynchronizer into an origin-equivalent one-way transducer. The result is in contrast with the usual semantics, where it is undecidable to know if a non-deterministic two-way transducer is equivalent to some one-way transducer.
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Ibarra, Oscar H., and Hsu-Chun Yen. "On Two-Way Transducers." In Developments in Language Theory, 300–311. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-22321-1_26.

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Feng, Fan, and Andreas Maletti. "Weighted Two-Way Transducers." In Algebraic Informatics, 101–14. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-19685-0_8.

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de Souza, Rodrigo. "Uniformisation of Two-Way Transducers." In Language and Automata Theory and Applications, 547–58. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-37064-9_48.

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Carton, Olivier. "Two-Way Transducers with a Two-Way Output Tape." In Developments in Language Theory, 263–72. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-31653-1_24.

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Douéneau-Tabot, Gaëtan. "Pebble minimization: the last theorems." In Lecture Notes in Computer Science, 436–55. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-30829-1_21.

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AbstractPebble transducers are nested two-way transducers which can drop marks (named “pebbles”) on their input word. Such machines can compute functions whose output size is polynomial in the size of their input. They can be seen as simple recursive programs whose recursion height is bounded. A natural problem is, given a pebble transducer, to compute an equivalent pebble transducer with minimal recursion height. This problem has been open since the introduction of the model.In this paper, we study two restrictions of pebble transducers, that cannot see the marks (“blind pebble transducers” introduced by Nguyên et al.), or that can only see the last mark dropped (“last pebble transducers” introduced by Engelfriet et al.). For both models, we provide an effective algorithm for minimizing the recursion height. The key property used in both cases is that a function whose output size is linear (resp. quadratic, cubic, etc.) can always be computed by a machine whose recursion height is 1 (resp. 2, 3, etc.). We finally show that this key property fails as soon as we consider machines that can see more than one mark.
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Baudru, Nicolas, and Pierre-Alain Reynier. "From Two-Way Transducers to Regular Function Expressions." In Developments in Language Theory, 96–108. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-98654-8_8.

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Engelfriet, Joost, and Sebastian Maneth. "Two-Way Finite State Transducers with Nested Pebbles." In Lecture Notes in Computer Science, 234–44. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/3-540-45687-2_19.

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Choffrut, Christian, and Bruno Guillon. "An Algebraic Characterization of Unary Two-Way Transducers." In Mathematical Foundations of Computer Science 2014, 196–207. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-44522-8_17.

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Smith, Tim. "A Pumping Lemma for Two-Way Finite Transducers." In Mathematical Foundations of Computer Science 2014, 523–34. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-44522-8_44.

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Conference papers on the topic "Two-way transducers"

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Filiot, Emmanuel, Olivier Gauwin, Pierre-Alain Reynier, and Frederic Servais. "From Two-Way to One-Way Finite State Transducers." In 2013 Twenty-Eighth Annual IEEE/ACM Symposium on Logic in Computer Science (LICS 2013). IEEE, 2013. http://dx.doi.org/10.1109/lics.2013.53.

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Baschenis, Felix, Olivier Gauwin, Anca Muscholl, and Gabriele Puppis. "Untwisting two-way transducers in elementary time." In 2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS). IEEE, 2017. http://dx.doi.org/10.1109/lics.2017.8005138.

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Dartois, Luc, Emmanuel Filiot, Pierre-Alain Reynier, and Jean-Marc Talbot. "Two-Way Visibly Pushdown Automata and Transducers." In LICS '16: 31st Annual ACM/IEEE Symposium on Logic in Computer Science. New York, NY, USA: ACM, 2016. http://dx.doi.org/10.1145/2933575.2935315.

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Stoppel, F., C. Eisermann, S. Gu-Stoppel, D. Kaden, T. Giese, and B. Wagner. "Novel membrane-less two-way MEMS loudspeaker based on piezoelectric dual-concentric actuators." In 2017 19th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS). IEEE, 2017. http://dx.doi.org/10.1109/transducers.2017.7994475.

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Hikmat, O. F., F. A. Mohd Ghazali, A. AbuZaiter, and M. S. Mohamed Ali. "A monolithic tunable out-of-plane inductor based on NiTi two-way shape-memory-alloy." In 2017 19th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS). IEEE, 2017. http://dx.doi.org/10.1109/transducers.2017.7994442.

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Lin, Yu-Tzu, Sung-Cheng Lo, and Weileun Fang. "Two-Way Piezoelectric MEMS Microspeaker with Novel Structure and Electrode Design for Bandwidth Enhancement." In 2021 21st International Conference on Solid-State Sensors, Actuators and Microsystems (Transducers). IEEE, 2021. http://dx.doi.org/10.1109/transducers50396.2021.9495444.

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Town, Jason, and Cengiz Camci. "Sub-Miniature Five-Hole Probe Calibration Using a Time Efficient Pitch and Yaw Mechanism and Accuracy Improvements." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-46391.

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A five-hole probe is a proven aerodynamic tool for the accurate measurement of flow fields, but is traditionally difficult to calibrate manually in an acceptable range of pitch and yaw angles. With advancements in computer technology, it is possible to improve the calibration process that is made up of tedious and repeating angular pitch and yaw angle movements. This paper proposes a way to increase the accuracy of measurements. The proposed approach uses computer automation, a mechanical pressure scanner, and precision rotary tables to significantly reduce the amount of time required to complete the calibration sequence. A five-hole probe is fastened to a precision calibration mechanism in a wind tunnel test section. This mechanism varied the pitch and yaw angle of the probe accurately via two computer controlled rotary tables. This approach allowed for a much greater degree of accuracy and a way to increase the number of data points taken, better defining the non-linear portions of the calibration maps. The scanivalve system minimized the number of transducers required from seven to one. While it takes more time than having multiple transducers, this approach lowered the overall equipment costs and helped to reduce measurement errors. The data acquisition device provides an interface between the rotary table stepper controllers, the scanivalve controller, and the transducer. A LabVIEW interface was then used to control all of the devices, while simultaneously retrieving data from the transducer and turning it into the coefficients needed to make the calibration map. The program allows for a degree of flexibility, allowing the user to choose the range of angles and the degrees between each point.
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Wang, X., and J. Tang. "Damage Detection Using Impedance Measurement With Magnetic Transducer." In ASME 2009 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2009. http://dx.doi.org/10.1115/smasis2009-1414.

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Impedance method has been explored for damage detection and identification. Typically, when the impedance sensor is integrated onto the mechanical structure to be monitored, its electrical impedance is directly related to the mechanical impedance of the host structure. Thus the change of impedance measurement before and after damage occurrence can be used as the damage indicator. Since the impedance information may be measured at relatively high frequency range, the impedance method could be sensitive to small-sized damage. Generally, piezoelectric transducers are employed in the impedance approach, which can serve as actuator and sensor simultaneously. In this research, a magnetic transducer approach is investigated for impedance based damage detection. To provide design guidelines, the analytical model of the resistive magnetic impedance measurement circuit is formulated. During the formulation, the two-way magneto-mechanical coupling between the transducer and the structure is systematically studied by using the Maxwell’s equations. The preliminary sensor enhancement is achieved by selecting the number of turns of wire in the electrical coil. Moreover, in order to reduce the negative effects of the high inherent inductance and large parasitic resistance of the coil with a large number of turns of wire, a new measurement circuitry is proposed, in which a negative resistive element and a capacitor are introduced to be serially connected with the original resistive circuit. Correlated numerical and experimental studies are carried out to validate the magnetic transducer in impedance based damage detection.
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Karpachevskyy, Taras, and Swavik Spiewak. "Gravity-Assisted, Passive Cancellation of Disturbances for Inertial Sensors." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-65775.

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Continuing enhancements in Microsystem Technologies facilitate the development of inertial sensors — accelerometers and gyroscopes — of unprecedented performance to cost ratio and broaden the frontiers of their application. Of particular interest, because of their immunity to ambient disturbances, are sensors equipped with high resolution Electro-Mechanical ΣΔ converters and with a high speed, digital serial signal transmission. The digital circuitry of these sensors reaches the accuracy of 0.02 parts-per-million (ppm). However, the analogue transducers of measured physical quantities into electrical signals inside of the even best inertial sensors are prone to inherent imperfections of analog systems such as nonlinearity, cross-sensitivity, or noise. The best accuracy of these transducers is about two orders of magnitude worse than that of the electrical circuitry. The overall accuracy can be greatly improved by using corrective filters that cancel the effects of imperfections in the analogue transducers. The effectiveness of these filters hinges upon the accuracy of identifying comprehensive models of the analogue transducers. Ambient disturbances, in particular mechanical vibrations, greatly deteriorate the accuracy of identification. Their impact can be attenuated to some extent by using vibration isolation platforms. The effectiveness of attenuation is usually good at the frequencies above 5–10 Hz, however it is poor at low frequencies. This poor attenuation is a significant disadvantage since the low frequency phenomena in inertial sensors have pronounced impact on their suitability for a broad class of applications (e.g., navigation). The presented research focuses on the design of a passive vibration isolation device in which horizontal movement is coupled to tilt in a way that a component of the gravity perceived by the tested inertial sensor effectively cancels out the horizontal acceleration coming from the ambient vibrations.
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10

Myers, M. R., A. B. Jorge, D. G. Walker, and M. J. Mutton. "Heat Source Localization Sensitivity Analyses for an Ultrasonic Sensor Array." In ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44120.

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State estimation procedures using the extended Kalman filter are investigated for a transient heat transfer problem in which a heat source is applied on one side of a thin plate and ultrasonic pulse time of flight is measured between spatially separated transducers on the other side of the plate. This work is an integral part of an effort to develop a system capable of locating the boundary layer transition region on a hypersonic vehicle aeroshell. Results from thermal conduction experiments involving one-way ultrasonic pulse time of flight measurements are presented. Uncertainties in the experiments and sensitivity to heating source location are discussed. Comparisons of heating source localization measurement models are conducted where ultrasonic pulse time of flight readings provide the measurement update to the extended Kalman filter. Two different measurement models are compared: 1) directly using the one-way ultrasonic pulse time of flight as the measurement vector and 2) indirectly obtaining distance from the one-way ultrasonic pulse time of flight and then using these obtained distances as the measurement vector in the extended Kalman filter. For the direct model, the Jacobian required by the extended Kalman filter is obtained numerically using finite differences from the finite element forward conduction solution. For the indirect model, the derivatives of the distances with respect to the state variables are obtained in closed form. Heating source localization results and convergence behavior are compared for the two measurement models. Two areas of sensitivity analyses are presented: 1) heat source location relative to sensor array position, and 2) sensor noise. The direct measurement model produced the best results when considering accuracy of converged solution, ability to converge to the correct solution given different initial guesses, and smoothness of convergence behavior.
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Reports on the topic "Two-way transducers"

1

Gil, Oliver Fernández, and Anni-Yasmin Turhan. Answering Regular Path Queries Under Approximate Semantics in Lightweight Description Logics. Technische Universität Dresden, 2020. http://dx.doi.org/10.25368/2022.261.

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Classical regular path queries (RPQs) can be too restrictive for some applications and answering such queries under approximate semantics to relax the query is desirable. While for answering regular path queries over graph databases under approximate semantics algorithms are available, such algorithms are scarce for the ontology-mediated setting. In this paper we extend an approach for answering RPQs over graph databases that uses weighted transducers to approximate paths from the query in two ways. The first extension is to answering approximate conjunctive 2-way regular path queries (C2RPQs) over graph databases and the second is to answering C2RPQs over ELH and DL-LiteR ontologies. We provide results on the computational complexity of the underlying reasoning problems and devise approximate query answering algorithms.
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