Articles de revues : « Weighted strings »

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ZHANG, MENG, LIANG HU et YI ZHANG. « WEIGHTED AUTOMATA FOR FULL-TEXT INDEXING ». International Journal of Foundations of Computer Science 22, n^o 04 (juin 2011) : 921–43. http://dx.doi.org/10.1142/s0129054111008490.

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Full-text index structures are widely used in string matching and bioinformatics. These structures such as DAWGs and suffix trees allow fast searches on texts. In this paper, we present a new partition of the factors of a word, called a consistent minimal linear partition. Based on this partition, we introduce the weighted directed word graph (WDWG), a space-economical full-text index. WDWGs are basically cyclic, which means that they may accept infinite strings. But by assigning weights to edges, the acceptable strings are limited only to the factors of the input string. For a given word w, any factor of w can be indexed by a state of the WDWG and its length. A WDWG of w has at most |w| states and 2|w| - 1 transition edges. We present an on-line algorithm to construct a WDWG for a given word in time linear in the length of the word. Our experiment shows the size of WDWGs is smaller than that of DAWGs for many data sets including DNA sequences, Chinese texts and English texts.

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MOHRI, MEHRYAR. « EDIT-DISTANCE OF WEIGHTED AUTOMATA : GENERAL DEFINITIONS AND ALGORITHMS ». International Journal of Foundations of Computer Science 14, n^o 06 (décembre 2003) : 957–82. http://dx.doi.org/10.1142/s0129054103002114.

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The problem of computing the similarity between two sequences arises in many areas such as computational biology and natural language processing. A common measure of the similarity of two strings is their edit-distance, that is the minimal cost of a series of symbol insertions, deletions, or substitutions transforming one string into the other. In several applications such as speech recognition or computational biology, the objects to compare are distributions over strings, i.e., sets of strings representing a range of alternative hypotheses with their associated weights or probabilities. We define the edit-distance of two distributions over strings and present algorithms for computing it when these distributions are given by automata. In the particular case where two sets of strings are given by unweighted automata, their edit-distance can be computed using the general algorithm of composition of weighted transducers combined with a single-source shortest-paths algorithm. In the general case, we show that general weighted automata algorithms over the appropriate semirings can be used to compute the edit-distance of two weighted automata exactly. These include classical algorithms such as the composition and ∊-removal of weighted transducers and a new and simple synchronization algorithm for weighted transducers which, combined with ∊-removal, can be used to normalize weighted transducers with bounded delays. Our algorithm for computing the edit-distance of weighted automata can be used to improve the word accuracy of automatic speech recognition systems. It can also be extended to provide an edit-distance automaton useful for re-scoring and other post-processing purposes in the context of large-vocabulary speech recognition.

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BROUTIN, N., et L. DEVROYE. « An Analysis of the Height of Tries with Random Weights on the Edges ». Combinatorics, Probability and Computing 17, n^o 2 (mars 2008) : 161–202. http://dx.doi.org/10.1017/s0963548307008796.

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We analyse the weighted height of random tries built from independent strings of i.i.d. symbols on the finite alphabet {1, . . .d}. The edges receive random weights whose distribution depends upon the number of strings that visit that edge. Such a model covers the hybrid tries of de la Briandais and the TST of Bentley and Sedgewick, where the search time for a string can be decomposed as a sum of processing times for each symbol in the string. Our weighted trie model also permits one to study maximal path imbalance. In all cases, the weighted height is shown to be asymptotic toclognin probability, wherecis determined by the behaviour of thecoreof the trie (the part where all nodes have a full set of children) and the fringe of the trie (the part of the trie where nodes have only one child and formspaghetti-like trees). It can be found by maximizing a function that is related to the Cramér exponent of the distribution of the edge weights.

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Hyyrö, Heikki, et Shunsuke Inenaga. « Dynamic RLE-Compressed Edit Distance Tables Under General Weighted Cost Functions ». International Journal of Foundations of Computer Science 29, n^o 04 (juin 2018) : 623–45. http://dx.doi.org/10.1142/s0129054118410083.

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Kim and Park [A dynamic edit distance table, J. Disc. Algo., 2:302–312, 2004] proposed a method (KP) based on a “dynamic edit distance table” that allows one to efficiently maintain unit cost edit distance information between two strings [Formula: see text] of length [Formula: see text] and [Formula: see text] of length [Formula: see text] when the strings can be modified by single-character edits to their left or right ends. This type of computation is useful e.g. in cyclic string comparison. KP uses linear time, [Formula: see text], to update the distance representation after each single edit. Recently Hyyrö et al. [Incremental string comparison, J. Disc. Algo., 34:2-17, 2015] presented an efficient method for maintaining the dynamic edit distance table under general weighted edit distance, running in [Formula: see text] time per single edit, where [Formula: see text] is the maximum weight of the cost function. The work noted that the [Formula: see text] space requirement, and not the running time, may be the main bottleneck in using the dynamic edit distance table. In this paper we take the first steps towards reducing the space usage of the dynamic edit distance table by RLE compressing [Formula: see text] and [Formula: see text]. Let [Formula: see text] and [Formula: see text] be the lengths of RLE compressed versions of [Formula: see text] and [Formula: see text], respectively. We propose how to store the dynamic edit distance table using [Formula: see text] space while maintaining the same time complexity as the previous methods for uncompressed strings.

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Louchard, Guy, et Wojciech Szpankowski. « A Probabilistic Analysis of a String Editing Problem and its Variations ». Combinatorics, Probability and Computing 4, n^o 2 (juin 1995) : 143–66. http://dx.doi.org/10.1017/s0963548300001541.

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We consider a string editing problem in a probabilistic framework. This problem is of considerable interest to many facets of science, most notably molecular biology and computer science. A string editing transforms one string into another by performing a series of weighted edit operations of overall maximum (minimum) cost. The problem is equivalent to finding an optimal path in a weighted grid graph. In this paper we provide several results regarding a typical behaviour of such a path. In particular, we observe that the optimal path (i.e. edit distance) is almost surely (a.s.) equal to αn for large n where α is a constant and n is the sum of lengths of both strings. More importantly, we show that the edit distance is well concentrated around its average value. In the so called independent model in which all weights (in the associated grid graph) are statistically independent, we derive some bounds for the constant α. As a by-product of our results, we also present a precise estimate of the number of alignments between two strings. To prove these findings we use techniques of random walks, diffusion limiting processes, generating functions, and the method of bounded difference.

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Barton, Carl, Chang Liu et Solon P. Pissis. « Fast Average-Case Pattern Matching on Weighted Sequences ». International Journal of Foundations of Computer Science 29, n^o 08 (décembre 2018) : 1331–43. http://dx.doi.org/10.1142/s0129054118430062.

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A weighted string is a string in which a set of letters may occur at each position with respective occurrence probabilities. Weighted strings, also known as position weight matrices, weighted sequences or uncertain sequences, naturally arise in many contexts. In this paper, we study the problem of weighted string matching with a special focus on average-case analysis. Given a weighted pattern string [Formula: see text] of length [Formula: see text], a text string [Formula: see text] of length [Formula: see text], both on a constant-sized alphabet of size [Formula: see text], and a cumulative weight threshold [Formula: see text], defined as the minimal probability of occurrence of factors in a weighted string, we present an on-line algorithm requiring average-case search time [Formula: see text] for pattern matching for weight ratio [Formula: see text]. For a pattern string [Formula: see text] of length [Formula: see text], a weighted text string [Formula: see text] of length [Formula: see text], both on a constant-sized alphabet, and a cumulative weight threshold [Formula: see text], we present an on-line algorithm requiring average-case search time [Formula: see text] for the same weight ratio. The importance of these algorithms lies on the fact that, for these ratios, they can work in sublinear search time in the size of the input text, and in linear preprocessing costs in the size of the pattern.

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Barton, Carl, et Solon P. Pissis. « Crochemore’s Partitioning on Weighted Strings and Applications ». Algorithmica 80, n^o 2 (27 janvier 2017) : 496–514. http://dx.doi.org/10.1007/s00453-016-0266-0.

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SADRI, JAVAD, CHING Y. SUEN et TIEN D. BUI. « STATISTICAL CHARACTERISTICS OF SLANT ANGLES IN HANDWRITTEN NUMERAL STRINGS AND EFFECTS OF SLANT CORRECTION ON SEGMENTATION ». International Journal of Pattern Recognition and Artificial Intelligence 24, n^o 01 (février 2010) : 97–116. http://dx.doi.org/10.1142/s0218001410007816.

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A novel and efficient method for correction of slant angles in handwritten numeral strings is proposed. For the first time, the statistical distribution of slant angles in handwritten numerals is investigated and the effects of slant correction on the segmentation of handwritten numeral strings are shown. In our proposed slant correction method, utilizing geometric features, a Component Slant Angle (CSA) is estimated for each connected component independently. A weighted average is then used to compute the String Slant Angle (SSA), which is applied uniformly to correct the slant of all the components in numeral strings. Our experimental results have revealed novel statistics for slant angles of handwritten numeral strings, and also showed that slant correction can significantly improve extraction of segmentation features and segmentation accuracy of touching numerals. Comparison between our slant correction algorithm and similar algorithms in the literature show that our algorithm is more efficient, and on average it has a faster running time.

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Alshawi, Hiyan, Srinivas Bangalore et Shona Douglas. « Learning Dependency Translation Models as Collections of Finite-State Head Transducers ». Computational Linguistics 26, n^o 1 (mars 2000) : 45–60. http://dx.doi.org/10.1162/089120100561629.

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The paper defines weighted head transducers, finite-state machines that perform middle-out string transduction. These transducers are strictly more expressive than the special case of standard left-to-right finite-state transducers. Dependency transduction models are then defined as collections of weighted head transducers that are applied hierarchically. A dynamic programming search algorithm is described for finding the optimal transduction of an input string with respect to a dependency transduction model. A method for automatically training a dependency transduction model from a set of input-output example strings is presented. The method first searches for hierarchical alignments of the training examples guided by correlation statistics, and then constructs the transitions of head transducers that are consistent with these alignments. Experimental results are given for applying the training method to translation from English to Spanish and Japanese.

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Cieliebak, Mark, Thomas Erlebach, Zsuzsanna Lipták, Jens Stoye et Emo Welzl. « Algorithmic complexity of protein identification : combinatorics of weighted strings ». Discrete Applied Mathematics 137, n^o 1 (février 2004) : 27–46. http://dx.doi.org/10.1016/s0166-218x(03)00187-2.

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Lintzmayer, Carla Negri, Guillaume Fertin et Zanoni Dias. « Sorting permutations and binary strings by length-weighted rearrangements ». Theoretical Computer Science 715 (mars 2018) : 35–59. http://dx.doi.org/10.1016/j.tcs.2018.01.012.

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Bansal, Nikhil, Mark Cieliebak et Zsuzsanna Lipták. « Finding submasses in weighted strings with Fast Fourier Transform ». Discrete Applied Mathematics 155, n^o 6-7 (avril 2007) : 707–18. http://dx.doi.org/10.1016/j.dam.2005.09.019.

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Bunke, Horst, Xiaoyi Jiang, Karin Abegglen et Abraham Kandel. « On the Weighted Mean of a Pair of Strings ». Pattern Analysis & ; Applications 5, n^o 1 (mai 2002) : 23–30. http://dx.doi.org/10.1007/s100440200003.

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Gajendragadkar, Uma, et Sarang Joshi. « Context Sensitive Search String Composition Algorithm using User Intention to Handle Ambiguous Keywords ». International Journal of Electrical and Computer Engineering (IJECE) 7, n^o 1 (1 février 2017) : 432. http://dx.doi.org/10.11591/ijece.v7i1.pp432-450.

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Finding the required URL among the first few result pages of a search engine is still a challenging task. This may require number of reformulations of the search string thus adversely affecting user's search time. Query ambiguity and polysemy are major reasons for not obtaining relevant results in the top few result pages. Efficient query composition and data organization are necessary for getting effective results. Context of the information need and the user intent may improve the autocomplete feature of existing search engines. This research proposes a Funnel Mesh-5 algorithm (FM5) to construct a search string taking into account context of information need and user intention with three main steps 1) Predict user intention with user profiles and the past searches via weighted mesh structure 2) Resolve ambiguity and polysemy of search strings with context and user intention 3) Generate a personalized disambiguated search string by query expansion encompassing user intention and predicted query. Experimental results for the proposed approach and a comparison with direct use of search engine are presented. A comparison of FM5 algorithm with K Nearest Neighbor algorithm for user intention identification is also presented. The proposed system provides better precision for search results for ambiguous search strings with improved identification of the user intention. Results are presented for English language dataset as well as Marathi (an Indian language) dataset of ambiguous search strings.

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MALETTI, ANDREAS, et DANIEL QUERNHEIM. « UNWEIGHTED AND WEIGHTED HYPER-MINIMIZATION ». International Journal of Foundations of Computer Science 23, n^o 06 (septembre 2012) : 1207–25. http://dx.doi.org/10.1142/s0129054112400485.

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Hyper-minimization of deterministic finite automata (DFA) is a recently introduced state reduction technique that allows a finite change in the recognized language. A generalization of this lossy compression method to the weighted setting over semifields is presented, which allows the recognized weighted language to differ for finitely many input strings. First, the structure of hyper-minimal deterministic weighted finite automata is characterized in a similar way as in classical weighted minimization and unweighted hyper-minimization. Second, an efficient hyper-minimization algorithm, which runs in time [Formula: see text], is derived from this characterization. Third, the closure properties of canonical regular languages, which are languages recognized by hyper-minimal DFA, are investigated. Finally, some recent results in the area of hyper-minimization are recalled.

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ALIEV, A. N. « ON THE ELECTROMAGNETIC PERTURBATIONS OF A MULTICONICAL SPACETIME ». Modern Physics Letters A 11, n^o 27 (7 septembre 1996) : 2171–77. http://dx.doi.org/10.1142/s0217732396002150.

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The electromagnetic perturbations propagating in the multiconical spacetime of N parallel cosmic strings are described. The expression for vacuum average of the stress-energy tensor is reduced to a form involving only zero-spin-weighted perturbation modes.

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Barton, Carl, Chang Liu et Solon P. Pissis. « Linear-time computation of prefix table for weighted strings & ; applications ». Theoretical Computer Science 656 (décembre 2016) : 160–72. http://dx.doi.org/10.1016/j.tcs.2016.04.029.

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Luo, Zhenkai, Binbin Jiao, Hang Zhao, Tao Huang, Lin Geng et Guan Zhang. « The Efficacy and Safety of Ureteric Stent Removal with Strings versus No Strings : Which Is Better ? » BioMed Research International 2020 (15 octobre 2020) : 1–10. http://dx.doi.org/10.1155/2020/4081409.

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Objective. To evaluate the current evidence on the effectiveness and safety of ureteric stent removal using strings compared to conventional methods. Materials and Methods. The electronic databases PubMed, Embase, China National Knowledge Infrastructure (CNKI), and the Cochrane Library were systematically searched up to March 2020. Two reviewers searched the literature, independently extracted the data, and evaluated the quality of the studies according to the inclusion and exclusion criteria. The data analysis was performed with the software program Review Manager 5.3. Results. Eleven studies with a total of 1809 patients were included in the analysis based on the inclusion criteria. Our meta-analysis showed that visual analogue scale (VAS) scores were significantly lower in the string group than in the conventional group (weighted mean difference (WMD) -2.63; 95% confidence interval (CI) -3.68, -1.58; P < 0.00001 ). In terms of stent dwell time, the string group had an advantage (WMD -9.53; 95% CI -14.20, -4.86; P < 0.0001 ). In addition, no significant differences in the occurrence of urinary tract infection (UTI) (odds ratio (OR) 1.03; 95% CI 0.62, 1.72; P = 0.92 ), emergency room visits (OR 0.99; 95% CI 0.59, 1.67; P = 0.97 ), or other complications ( P > 0.05 ) were observed between the two groups. Conclusion. Our findings suggest that an extraction string is an effective and safe method for the removal of ureteric stents. This method gives patients the benefits of reduced pain and shortened stent dwell time without increasing the risk of UTI. Nevertheless, these findings should be further confirmed through large-volume, well-designed prospective randomized controlled trials (RCTs).

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Chiang, David, Frank Drewes, Daniel Gildea, Adam Lopez et Giorgio Satta. « Weighted DAG Automata for Semantic Graphs ». Computational Linguistics 44, n^o 1 (mars 2018) : 119–86. http://dx.doi.org/10.1162/coli_a_00309.

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Graphs have a variety of uses in natural language processing, particularly as representations of linguistic meaning. A deficit in this area of research is a formal framework for creating, combining, and using models involving graphs that parallels the frameworks of finite automata for strings and finite tree automata for trees. A possible starting point for such a framework is the formalism of directed acyclic graph (DAG) automata, defined by Kamimura and Slutzki and extended by Quernheim and Knight. In this article, we study the latter in depth, demonstrating several new results, including a practical recognition algorithm that can be used for inference and learning with models defined on DAG automata. We also propose an extension to graphs with unbounded node degree and show that our results carry over to the extended formalism.

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Pang, Peijie. « Design of Tone Recognition System for Pipa Strings Based on Wireless Sensors ». Mobile Information Systems 2022 (9 mai 2022) : 1–8. http://dx.doi.org/10.1155/2022/1670848.

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Pipa has been widely used as a wooden musical instrument as early as the Han period. It mainly relies on human fingers to pluck the strings to make sounds. The timbre of the pipa also has a very strong national characteristic. Understanding the meaning of words, phrases, and sentences requires tone recognition. For tone identification, the fundamental frequency conveys the most unique information. This paper summarizes the influence of the pipa’s characteristics, technology and skills of the player, and the player’s factors on the timbre of the pipa performance. In addition, given the problems of low accuracy and high data packet loss rate in the existing pipa playing tone recognition methods, this paper proposes a pipa string playing tone recognition algorithm based on wireless sensors. According to the sensor stage and weight-corresponding characteristics, on the premise of minimizing the total mean square error, the optimal weight corresponding to the sensor measurement value is found according to the adaptive mode. The unbiased estimated value of the measured value of each node is obtained through iterative calculation. The Euclidean distance between the measured value and the estimated value of each sensor obtained by the normalization process is used as the adaptive weighted recognition weight. It completes the conversion of the adaptive weighted recognition algorithm structure and the binary recognition result. The experimental results show that the proposed method has good tonal recognition accuracy in the pipa playing environment.

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McWhirter, Paul R., Kashif Kifayat, Qi Shi et Bob Askwith. « SQL Injection Attack classification through the feature extraction of SQL query strings using a Gap-Weighted String Subsequence Kernel ». Journal of Information Security and Applications 40 (juin 2018) : 199–216. http://dx.doi.org/10.1016/j.jisa.2018.04.001.

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Gui, Ruowei, Liu Yang et Xiaolin Gui. « An Order-Preserving Encryption Scheme Based on Weighted Random Interval Division for Ciphertext Comparison in Wearable Systems ». Sensors 22, n^o 20 (18 octobre 2022) : 7950. http://dx.doi.org/10.3390/s22207950.

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With the rapid development of wearable devices with various sensors, massive sensing data for health management have been generated. This causes a potential revolution in medical treatments, diagnosis, and prediction. However, due to the privacy risks of health data aggregation, data comparative analysis under privacy protection faces challenges. Order-preserving encryption is an effective scheme to achieve private data retrieval and comparison, but the existing order-preserving encryption algorithms are mainly aimed at either integer data or single characters. It is urgent to build a lightweight order-preserving encryption scheme that supports multiple types of data such as integer, floating number, and string. In view of the above problems, this paper proposes an order-preserving encryption scheme (WRID-OPES) based on weighted random interval division (WRID). WRID-OPES converts all kinds of data into hexadecimal number strings and calculates the frequency and weight of each hexadecimal number. The plaintext digital string is blocked and recombined, and each block is encrypted using WRID algorithm according to the weight of each hexadecimal digit. Our schemes can realize the order-preserving encryption of multiple types of data and achieve indistinguishability under ordered selection plaintext attack (IND-OCPA) security in static data sets. Security analysis and experiments show that our scheme can resist attacks using exhaustive methods and statistical methods and has linear encryption time and small ciphertext expansion rate.

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Clark, Alexander, et Nathanaël Fijalkow. « Consistent Unsupervised Estimators for Anchored PCFGs ». Transactions of the Association for Computational Linguistics 8 (juillet 2020) : 409–22. http://dx.doi.org/10.1162/tacl_a_00323.

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Learning probabilistic context-free grammars (PCFGs) from strings is a classic problem in computational linguistics since Horning ( 1969 ). Here we present an algorithm based on distributional learning that is a consistent estimator for a large class of PCFGs that satisfy certain natural conditions including being anchored (Stratos et al., 2016 ). We proceed via a reparameterization of (top–down) PCFGs that we call a bottom–up weighted context-free grammar. We show that if the grammar is anchored and satisfies additional restrictions on its ambiguity, then the parameters can be directly related to distributional properties of the anchoring strings; we show the asymptotic correctness of a naive estimator and present some simulations using synthetic data that show that algorithms based on this approach have good finite sample behavior.

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Kim, Janghwan, Jeeyoung Lim, Hyoung-Chul Lim et Dae Young Kim. « Improving Sustainable Project Success Strategies Focused on Cost and Schedule for Electrical Construction Project Management ». Sustainability 14, n^o 5 (24 février 2022) : 2653. http://dx.doi.org/10.3390/su14052653.

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Electrical contractors encounter problems such as limited construction sites, schedule interference, and inefficient communication with other contractors when they typically subcontract with general contractors. Electrical projects require effective and systematic project management strategies to overcome these problems and achieve the desired goal. In an electrical construction project, individual tasks are interconnected at different stages, including pre-construction planning (PCP) and project execution (PE). Therefore, analyzing the effect of task strings on the project success in terms of schedule and cost performance is necessary. The main objective of this study is to perform a static analysis to compare successful and failed projects with a focus on the cost and schedule performances, using the PCP and PE task strings in electrical construction projects. To achieve this, a continuous PCP-PE task strings implementation score was calculated for each PE group in terms of cost and schedule, and successful and failed projects on unweighted and weighted values were compared and analyzed by performing an independent sample t-test. Consequently, it was confirmed that the use of most task strings had a positive effect on the cost success at a confidence level of 95%, and that only the subcontractor management group had a positive effect on the schedule success. Hence, it was derived that the usage of task strings for these groups is recommended for cost success in electrical construction, and continuous PCP-PE task strings do not have a positive effect on schedule success; therefore, it is recommended to use the PCP-PE task strings only for specific groups for schedule success in electrical construction. Demonstrating the relationship between the PCP and PE tasks, the findings of this study are expected to help electrical contractors achieve a better performance using effective project management strategies.

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Lapidus, Michel L. « Towards quantized number theory : spectral operators and an asymmetric criterion for the Riemann hypothesis ». Philosophical Transactions of the Royal Society A : Mathematical, Physical and Engineering Sciences 373, n^o 2047 (6 août 2015) : 20140240. http://dx.doi.org/10.1098/rsta.2014.0240.

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This research expository article not only contains a survey of earlier work but also contains a main new result, which we first describe. Given c ≥0, the spectral operator can be thought of intuitively as the operator which sends the geometry onto the spectrum of a fractal string of dimension not exceeding c . Rigorously, it turns out to coincide with a suitable quantization of the Riemann zeta function ζ = ζ ( s ): , where ∂=∂ c is the infinitesimal shift of the real line acting on the weighted Hilbert space . In this paper, we establish a new asymmetric criterion for the Riemann hypothesis (RH), expressed in terms of the invertibility of the spectral operator for all values of the dimension parameter (i.e. for all c in the left half of the critical interval (0,1)). This corresponds (conditionally) to a mathematical (and perhaps also, physical) ‘phase transition’ occurring in the midfractal case when . Both the universality and the non-universality of ζ = ζ ( s ) in the right (resp., left) critical strip (resp., ) play a key role in this context. These new results are presented here. We also briefly discuss earlier joint work on the complex dimensions of fractal strings, and we survey earlier related work of the author with Maier and with Herichi, respectively, in which were established symmetric criteria for the RH, expressed, respectively, in terms of a family of natural inverse spectral problems for fractal strings of Minkowski dimension D ∈(0,1), with , and of the quasi-invertibility of the family of spectral operators (with ).

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Smith, Noah A., et Mark Johnson. « Weighted and Probabilistic Context-Free Grammars Are Equally Expressive ». Computational Linguistics 33, n^o 4 (décembre 2007) : 477–91. http://dx.doi.org/10.1162/coli.2007.33.4.477.

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This article studies the relationship between weighted context-free grammars (WCFGs), where each production is associated with a positive real-valued weight, and probabilistic context-free grammars (PCFGs), where the weights of the productions associated with a nonterminal are constrained to sum to one. Because the class of WCFGs properly includes the PCFGs, one might expect that WCFGs can describe distributions that PCFGs cannot. However, Z. Chi (1999, Computational Linguistics, 25(1):131–160) and S. P. Abney, D. A. McAllester, and P. Pereira (1999, In Proceedings of the 37th Annual Meeting of the Association for Computational Linguistics, pages 542–549, College Park, MD) proved that every WCFG distribution is equivalent to some PCFG distribution. We extend their results to conditional distributions, and show that every WCFG conditional distribution of parses given strings is also the conditional distribution defined by some PCFG, even when the WCFG's partition function diverges. This shows that any parsing or labeling accuracy improvement from conditional estimation of WCFGs or conditional random fields (CRFs) over joint estimation of PCFGs or hidden Markov models (HMMs) is due to the estimation procedure rather than the change in model class, because PCFGs and HMMs are exactly as expressive as WCFGs and chain-structured CRFs, respectively.

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CHAMPARNAUD, JEAN-MARC, FRANCK GUINGNE, ANDRÉ KEMPE et FLORENT NICART. « ALGORITHMS FOR THE JOIN AND AUTO-INTERSECTION OF MULTI-TAPE WEIGHTED FINITE-STATE MACHINES ». International Journal of Foundations of Computer Science 19, n^o 02 (avril 2008) : 453–76. http://dx.doi.org/10.1142/s0129054108005760.

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A weighted finite-state machine with n tapes describes a rational relation on n strings. We recall some basic operations on n-ary rational relations, recast the important join operation in terms of "auto-intersection", and propose restricted algorithms for both operations. If two rational relations are joined on more than one tape, it can unfortunately lead to non-rational relations with undecidable properties. As a consequence, there cannot be a fully general algorithm, able to compile any rational join or auto-intersection. We define a class of triples 〈A,i,j〉 for which we are able to compile the auto-intersection of the machine A w.r.t. tapes i and j. We hope that this class is sufficient for many practical applications.

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Schmidt, Jeanette P. « All Highest Scoring Paths in Weighted Grid Graphs and Their Application to Finding All Approximate Repeats in Strings ». SIAM Journal on Computing 27, n^o 4 (août 1998) : 972–92. http://dx.doi.org/10.1137/s0097539795288489.

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Liu, Xin, Ren Ren Liu et Wen Jing He. « A Fast Algorithm for Chinese Text Categorization Based on Key Tree ». Applied Mechanics and Materials 58-60 (juin 2011) : 1106–12. http://dx.doi.org/10.4028/www.scientific.net/amm.58-60.1106.

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To solving Chinese text categorization, a fast algorithm is proposed. The basic idea of the algorithm is: first constructs a weighted value of keywords dictionary which is constructed in key tree, then using the Hash function and the principle of giving priority for long term matching to mapping the strings in documentations to the dictionary. After that, calculate the sum of weights of the keywords which has been matched successfully. Finally take the maximum for the result of the classification. The algorithm can avoid the difficulty of Chinese word segmentation and its influence on accuracy of result. Theoretical analysis and experimental results indicate that the accuracy and the time efficiency of the algorithm is higher, whose comprehensive performance reaches to the level of current major technology.

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Kishino, Mika, et Kanako Komiya. « Extracting Linguistic Speech Patterns of Japanese Fictional Characters using Subword Units ». International Journal on Natural Language Computing 11, n^o 1 (28 février 2022) : 1–14. http://dx.doi.org/10.5121/ijnlc.2022.11101.

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This study extracted and analyzed the linguistic speech patterns that characterize Japanese anime or game characters. Conventional morphological analyzers, such as MeCab, segment words with high performance, but they are unable to segment broken expressions or utterance endings that are not listed in the dictionary, which often appears in lines of anime or game characters. To overcome this challenge, we propose segmenting lines of Japanese anime or game characters using subword units that were proposed mainly for deep learning, and extracting frequently occurring strings to obtain expressions that characterize their utterances. We analyzed the subword units weighted by TF/IDF according to gender, age, and each anime character and show that they are linguistic speech patterns that are specific for each feature. Additionally, a classification experiment shows that the model with subword units outperformed that with the conventional method.

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Pereira, Fernando Carlos Neves. « Grapheme-to-phoneme conversion of digit strings using weighted finite state transducers to apply grammar to powers of a number basis ». Journal of the Acoustical Society of America 105, n^o 2 (1999) : 587. http://dx.doi.org/10.1121/1.427009.

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Jelbert, Sarah A., Rachael Miller, Martina Schiestl, Markus Boeckle, Lucy G. Cheke, Russell D. Gray, Alex H. Taylor et Nicola S. Clayton. « New Caledonian crows infer the weight of objects from observing their movements in a breeze ». Proceedings of the Royal Society B : Biological Sciences 286, n^o 1894 (9 janvier 2019) : 20182332. http://dx.doi.org/10.1098/rspb.2018.2332.

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Humans use a variety of cues to infer an object's weight, including how easily objects can be moved. For example, if we observe an object being blown down the street by the wind, we can infer that it is light. Here, we tested whether New Caledonian crows make this type of inference. After training that only one type of object (either light or heavy) was rewarded when dropped into a food dispenser, birds observed pairs of novel objects (one light and one heavy) suspended from strings in front of an electric fan. The fan was either on—creating a breeze which buffeted the light, but not the heavy, object—or off, leaving both objects stationary. In subsequent test trials, birds could drop one, or both, of the novel objects into the food dispenser. Despite having no opportunity to handle these objects prior to testing, birds touched the correct object (light or heavy) first in 73% of experimental trials, and were at chance in control trials. Our results suggest that birds used pre-existing knowledge about the behaviour exhibited by differently weighted objects in the wind to infer their weight, using this information to guide their choices.

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Zeakis, Alexandros, Dimitrios Skoutas, Dimitris Sacharidis, Odysseas Papapetrou et Manolis Koubarakis. « TokenJoin ». Proceedings of the VLDB Endowment 16, n^o 4 (décembre 2022) : 790–802. http://dx.doi.org/10.14778/3574245.3574263.

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Set similarity join is an important problem with many applications in data discovery, cleaning and integration. To increase robustness, fuzzy set similarity join calculates the similarity of two sets based on maximum weighted bipartite matching instead of set overlap. This allows pairs of elements, represented as sets or strings, to also match approximately rather than exactly, e.g., based on Jaccard similarity or edit distance. However, this significantly increases the verification cost, making even more important the need for efficient and effective filtering techniques to reduce the number of candidate pairs. The current state-of-the-art algorithm relies on similarity computations between pairs of elements to filter candidates. In this paper, we propose token-based instead of element-based filtering, showing that it is significantly more lightweight, while offering similar or even better pruning effectiveness. Moreover, we address the top- k variant of the problem, alleviating the need for a user-specified similarity threshold. We also propose early termination to reduce the cost of verification. Our experimental results on six real-world datasets show that our approach always outperforms the state of the art, being an order of magnitude faster on average.

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Little, IP, et DR Ross. « The Levenshtein metric, a new means for soil classification tested by data from a sand-podzol chronosequence and evaluated by discriminant function analysis ». Soil Research 23, n^o 2 (1985) : 115. http://dx.doi.org/10.1071/sr9850115.

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Soil profiles are difficult to compare by statistical methods because sampling depths and intervals and the number of samples per profile may vary. This paper discusses a novel method for handling the problem. Chemical data from 52 soil profiles, which formed a chronosequence of podzols from Fraser Island, south-eastern Queensland, was classified using the Levenshtein metric. The soils varied from undifferentiated sands to deeply weathered podzols with many metres of bleached A, horizon. The data used were the proportions by weight in the soil samples of Na, K, Ca, Mg, Fe and Al extracted by mild acid digests. A polythetic divisive program was used to form seven groups from a matrix of six attributes and 573 samples. These groups were used to code profiles into strings of digits whose length equalled the number of samples in a profile. The Levenshtein metric then formed these strings into a dissimilarity matrix, which in turn was used to produce groups by an agglomerative hierarchical procedure. The groups produced by this procedure were checked using discriminant function analysis applied to depth function parameters derived from the original data set used in the pattern analysis procedures. These parameters were derived from a model which is consistent with ideas of soil genesis, hence their use should favour a classification related to soil development. The classificatory procedure could also be weighted for the depth to the B horizon, a procedure that was considered to be a direct weighting for the degree of soil development. Discriminant function analysis showed that the groups produced could be discriminated on the basis of depth function parameters regardless of any depth weighting. The groups were consistent with the known geochronology, but contained an important component due to other factors such as parent material and surface accumulation due to plant activity. Classification involving the Levenshtein metric proved to be a sound means of taking adequate account of the variation present in the data. Supplementary procedures provided by TAXON enable fresh insights into the nature of the individuals and their interrelationships to be obtained.

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Pérez Archila, Luis Miguel, Juan David Bastidas-Rodríguez, Rodrigo Correa, Luz Adriana Trejos Grisales et Daniel Gonzalez-Montoya. « A Solution of Implicit Model of Series-Parallel Photovoltaic Arrays by Using Deterministic and Metaheuristic Global Optimization Algorithms ». Energies 13, n^o 4 (12 février 2020) : 801. http://dx.doi.org/10.3390/en13040801.

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The implicit model of photovoltaic (PV) arrays in series-parallel (SP) configuration does not require the LambertW function, since it uses the single-diode model, to represent each submodule, and the implicit current-voltage relationship to construct systems of nonlinear equations that describe the electrical behavior of a PV generator. However, the implicit model does not analyze different solution methods to reduce computation time. This paper formulates the solution of the implicit model of SP arrays as an optimization problem with restrictions for all the variables, i.e., submodules voltages, blocking diode voltage, and strings currents. Such an optimization problem is solved by using two deterministic (Trust-Region Dogleg and Levenberg Marquard) and two metaheuristics (Weighted Differential Evolution and Symbiotic Organism Search) optimization algorithms to reproduce the current–voltage (I–V) curves of small, medium, and large generators operating under homogeneous and non-homogeneous conditions. The performance of all optimization algorithms is evaluated with simulations and experiments. Simulation results indicate that both deterministic optimization algorithms correctly reproduce I–V curves in all the cases; nevertheless, the two metaheuristic optimization methods only reproduce the I–V curves for small generators, but not for medium and large generators. Finally, experimental results confirm the simulation results for small arrays and validate the reference model used in the simulations.

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Bekas, D. G., M. Mora Mendias, Zahra Sharif Khodaei, Evangelos Karachalios, F. J. Chamorro Alonso et Ferri M. H. Aliabadi. « SHM of Composite Mono-Stringer Elements Based on Guided Waves ». Key Engineering Materials 827 (décembre 2019) : 464–69. http://dx.doi.org/10.4028/www.scientific.net/kem.827.464.

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In this work, the applicability of structural health monitoring (SHM) technique for damage detection in two composite mono-stringers representative of composite fuselage are investigated. The two different manufacturing technologies are co-curing and co-bonding of composite mono-stringers to the skin. The panels were then impacted at the foot of the stringer to cause Barely Visible Impact Damage (BVID). Piezoelectric transducers were surface mounted on the mono-stringers, guided wave measurements before and after impact were taken and used for detecting damage based on Weighted Energy Arrival Method (WEAM).

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Das, Shibsankar, et Kalpesh Kapoor. « Weighted approximate parameterized string matching ». AKCE International Journal of Graphs and Combinatorics 14, n^o 1 (1 avril 2017) : 1–12. http://dx.doi.org/10.1016/j.akcej.2016.11.010.

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Bertossi, Alan A., Fabrizio Luccio, Elena Lodi et Linda Pagli. « String matching with weighted errors ». Theoretical Computer Science 73, n^o 3 (juillet 1990) : 319–28. http://dx.doi.org/10.1016/0304-3975(90)90182-h.

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Wacher, Abigail, Ian Sobey et Keith Miller. « String gradient weighted moving finite elements ». International Journal for Numerical Methods in Fluids 47, n^o 10-11 (2005) : 1329–36. http://dx.doi.org/10.1002/fld.872.

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Eger, Steffen, Tim vor der Brück et Alexander Mehler. « A Comparison of Four Character-Level String-to-String Translation Models for (OCR) Spelling Error Correction ». Prague Bulletin of Mathematical Linguistics 105, n^o 1 (1 avril 2016) : 77–99. http://dx.doi.org/10.1515/pralin-2016-0004.

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Abstract We consider the isolated spelling error correction problem as a specific subproblem of the more general string-to-string translation problem. In this context, we investigate four general string-to-string transformation models that have been suggested in recent years and apply them within the spelling error correction paradigm. In particular, we investigate how a simple ‘k-best decoding plus dictionary lookup’ strategy performs in this context and find that such an approach can significantly outdo baselines such as edit distance, weighted edit distance, and the noisy channel Brill and Moore model to spelling error correction. We also consider elementary combination techniques for our models such as language model weighted majority voting and center string combination. Finally, we consider real-world OCR post-correction for a dataset sampled from medieval Latin texts.

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Tian, Shengfeng, Shaomin Mu et Chuanhuan Yin. « Length-weighted string kernels for sequence data classification ». Pattern Recognition Letters 28, n^o 13 (octobre 2007) : 1651–56. http://dx.doi.org/10.1016/j.patrec.2007.04.008.

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ISHIDA, Ryohei, et Masahiro NOGUCHI. « E4 Light Weighted Plane with Inflatable Stringer ». Proceedings of the Space Engineering Conference 2009.18 (2010) : 103–6. http://dx.doi.org/10.1299/jsmesec.2009.18.103.

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Damaschke, Peter. « Homogeneous String Segmentation using Trees and Weighted Independent Sets ». Algorithmica 57, n^o 4 (13 septembre 2008) : 621–40. http://dx.doi.org/10.1007/s00453-008-9225-8.

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Adelman, Joshua L., et Michael Grabe. « Simulating rare events using a weighted ensemble-based string method ». Journal of Chemical Physics 138, n^o 4 (28 janvier 2013) : 044105. http://dx.doi.org/10.1063/1.4773892.

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AHN, CHANGHYUN. « ${\mathcal N} = 2$ CONFORMAL SUPERGRAVITY FROM TWISTOR-STRING THEORY ». International Journal of Modern Physics A 21, n^o 18 (20 juillet 2006) : 3733–59. http://dx.doi.org/10.1142/s0217751x06033787.

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A chiral superfield strength in [Formula: see text] conformal supergravity at linearized level is obtained by acting two superspace derivatives on [Formula: see text] chiral superfield strength which can be described in terms of [Formula: see text] twistor superfields. By decomposing SU (4)R representation of [Formula: see text] twistor superfields into the SU (2)R representation with an invariant U (1)R charge, the surviving [Formula: see text] twistor superfields contain the physical states of [Formula: see text] conformal supergravity. These [Formula: see text] twistor superfields are functions of homogeneous coordinates of weighted complex projective space WCP3|4 where the two weighted fermionic coordinates have weight -1 and 3.

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Ahammad, Sk Hasane, V. Rajesh, A. Neetha, Sai Jeesmitha B et A. Srikanth. « Automatic segmentation of spinal cord diffusion MR Images for disease location finding ». Indonesian Journal of Electrical Engineering and Computer Science 15, n^o 3 (1 septembre 2019) : 1313. http://dx.doi.org/10.11591/ijeecs.v15.i3.pp1313-1321.

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Dissemination weighted MR imaging may build the affectability and explicitness of MR imaging for certain pathologic states of the spinal rope yet is once in a while performed as a result of a few specialized issues. We consequently tried a novel stage explored turn reverberation dispersion weighted interleaved reverberation planar imaging arrangement in seven sound volunteers and six patients with intramedullary injuries. We performed dispersion weighted MR imaging of the spinal string with high spatial goals. Distinctive examples of dissemination irregularities saw in patient investigations bolster the conceivable symptomatic effect of dispersion weighted MR imaging for ailments of the spinal string. MR imaging has turned into the system of decision for imaging the spinal rope on account of a high affectability for pathologic intra medullary changes. In any case, the explicitness of anomalies oftentimes lingers behind when utilizing just regular MR arrangements. Dissemination weighted MR imaging guarantees to supply additional data in light of trademark changes of the clear dispersion coefficient, for example, those showed in intense ischemia, tumors, or sores related among numerous sclerosis. To date, the indicative commitment of dispersion weighted MR imaging has been concerted essentially in the cerebrum since dissemination weighted MR imaging of the spine is in detail every one the more requesting. Both the little size of the spinal rope and movement-initiated antiquities must be considered. We in this manner built up another examination strategy and tried its unwavering quality and potential for adding to the symptomatic workup of patients with spinal rope indications.

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Jiang, Hao, et Wai Ki Ching. « Physico-Chemically Weighted Kernel for SVM Protein Classification ». Applied Mechanics and Materials 195-196 (août 2012) : 385–90. http://dx.doi.org/10.4028/www.scientific.net/amm.195-196.385.

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In this paper, a novel kernel taking into consideration of the physico-chemical properties of amino acids as well as the motif information is proposed to tackle the problem of protein classification. Similarity matrix is constructed based on an AAindex2 substitution matrix which measures the amino acid pair distance. Together with the motif content posing importance on the protein sequences, a new kernel is constructed. Numerical examples indicate that the string-based kernel in conjunction with SVM classifier performs significantly better than the traditional spectrum kernel method.

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LINET, B. « SPIN-WEIGHTED GREEN’S FUNCTIONS IN A CONICAL SPACE ». Modern Physics Letters A 11, n^o 39n40 (28 décembre 1996) : 3075–79. http://dx.doi.org/10.1142/s0217732396003052.

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We give an analysis of the spin-weighted Green’s functions in a conical space. We apply these results in the case of a straight cosmic string and in the Rindler space in order to determine generally the Euclidean Green’s functions for the massless spin-1/2 field and for the electromagnetic field. We give also the corresponding Green’s functions at zero temperature. However, except for the scalar field, it seems that these Euclidean Green’s functions do not correspond to the thermal Feynman Green’s functions.

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AB-AZIZ, M. T. S., A. MARZUKI et Z. A. A. AZIZ. « 12-BIT PSEUDO-DIFFERENTIAL CURRENT-SOURCE RESISTOR-STRING HYBRID DAC ». Journal of Circuits, Systems and Computers 20, n^o 04 (juin 2011) : 709–25. http://dx.doi.org/10.1142/s0218126611007566.

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This paper discusses a hybrid Digital-Analog Converter (DAC) architecture which is a combination of a binary-weighted resistor approach for eight bits in the least-significant-bit and thermometer coded approach for four bits in the most-significant-bit. The proposed design combines advantages of the binary-weighted resistor approach and thermometer coded approach. The final design is composed of two 12-bit DACs to achieve a pseudo differential output signal. The converter was designed with a Silterra 0.18 μm 1.8 V/3.3 V CMOS process technology. The post-layout simulation results show that this design achieves 12-bit resolution with INL and DNL of 0.375 LSB and 0.25 LSB, respectively. The power consumption is 6.291 mW when the designed DAC is biased with supply voltage equal to 3 V. The performance is accomplished with a design area of 230 μm × 255 μm.

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Wacher, A., et S. Kaja. « Aggregation of microglia in 2D with string gradient weighted moving finite elements ». Mathematical Methods in the Applied Sciences 36, n^o 13 (6 décembre 2012) : 1649–63. http://dx.doi.org/10.1002/mma.2710.

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