Context-Free Path Querying with Structural Representation of Result

Graph data model and graph databases are very popular in various areas such as bioinformatics, semantic web, and social networks. One specific problem in the area is a path querying with constraints formulated in terms of formal grammars. The query in this approach is written as grammar, and paths querying is graph parsing with respect to given grammar. There are several solutions to it, but how to provide structural representation of query result which is practical for answer processing and debugging is still an open problem. In this paper we propose a graph parsing technique which allows one to build such representation with respect to given grammar in polynomial time and space for arbitrary context-free grammar and graph. Proposed algorithm is based on generalized LL parsing algorithm, while previous solutions are based mostly on CYK or Earley algorithms, which reduces time complexity in some cases.Comment: Evaluation extende

Generation of THz frequency using PANDA ring resonator for THz imaging

In this study, we have generated terahertz (THz) frequency by a novel design of microring resonators for medical applications. The dense wavelength-division multiplexing can be generated and obtained by using a Gaussian pulse propagating within a modified PANDA ring resonator and an add/drop filter system. Our results show that the THz frequency region can be obtained between 40–50 THz. This area of frequency provides a reliable frequency band for THz pulsed imaging

Island Grammar-based Parsing using GLL and Tom

International audienceExtending a language by embedding within it another language presents significant parsing challenges, especially if the embedding is recursive. The composite grammar is likely to be nondeterministic as a result of tokens that are valid in both the host and the embedded language. In this paper we examine the challenges of embedding the Tom language into a variety of general-purpose high level languages. Tom provides syntax and semantics for advanced pattern matching and tree rewriting facilities. Embedded Tom constructs are translated into the host language by a preprocessor, the output of which is a composite program written purely in the host language. Tom implementations exist for Java, C, C#, Python and Caml. The current parser is complex and difficult to maintain. In this paper, we describe how Tom can be parsed using island grammars implemented with the Generalised LL (GLL) parsing algorithm. The grammar is, as might be expected, ambiguous. Extracting the correct derivation relies on our disambiguation strategy which is based on pattern matching within the parse forest. We describe different classes of ambiguity and propose patterns for resolving them

Optical dark and bright soliton generation and amplification

We propose two designed systems consist of series of micro ring resonator (MRR) and an add/drop filter in which the optical dark and bright soliton pulse propagating within the nonlinear waveguides can be amplified which can be used in long communication system. The dark or bright soliton is input into designed systems and travels within the waveguide. A continuous soliton pulse is sliced into smaller pulses by the nonlinear effect which is known as chaos. The power amplification occurs when the soliton propagates along the MRRs or add/drop filter systems. The add/drop filter system can itself be used to amplify the optical soliton when the bright soliton is input at the drop part of the system. It this work we have studied the generation of amplified pulse of optical dark and bright soliton when they propagating inside single systems or when they interact and collide during propagation inside an add/drop filter system. It means that amplified soliton pulse also can be obtained when two types of soliton i.e., dark and bright soliton collide with each other in a same system. In such a way the amplified dark soliton or bright soliton can be used to perform the long distance link

Iguana: a practical data-dependent parsing framework

Data-dependent grammars extend context-free grammars with arbitrary computation, variable binding, and constraints. These features provide the user with the freedom and power to express syntactic constructs outside the realm of context-free grammars, e.g., indentation rules in Haskell and type definitions in C. Data-dependent grammars have been recently presented by Jim et al. as a grammar formalism that enables construction of parsers from a rich format specification. Although some features of data-dependent grammars are available in current parsing tools, e.g., semantic predicates in ANTLR, data-dependent grammars have not yet fully found their way into practice. In this paper we present Iguana, a data-dependent parsing framework, implemented on top of the GLL parsing algorithm. In addition to basic features of data-dependent grammars, Iguana also provides high-level syntactic constructs, e.g., for operator precedence and indentation rules, which are implemented as desugaring to data-dependent grammars. These high-level constructs enable a concise and declarative way to define the syntax of programming languages. Moreover, Iguana's extensible data-dependent grammar API allows the user to easily add new high-level constructs or modify existing ones. We have used Iguana to parse various real programming languages, such as OCaml, Haskell, Java, and C#. In this paper we describe the architecture and features of Iguana, and report on its current implementation status

Generation of quantum codes using up and down link optical soliton

In this study, a system of continuous variable quantum code via a wavelength router is presented. The optical Kerr type nonlinearity in the nonlinear microring resonator (NMRR) induces the chaotic behavior. In this proposed system chaotic signals are generated by an optical soliton or Gaussian pulse within a NMRR system. Large bandwidth signals of optical soliton are generated by the input pulse propagating within the MRRs, which is allowed to form the continuous wavelength or frequency with large tunable channel capacity. Therefore, distinguished up and down links of wavelength or frequency pulses can be generated by using localized spatial soliton via a quantum router and networks. These selected up and down links pulses are more suitable to generate high secured quantum codes because of the greater free spectral range (FSR). The continuous quantum codes can be generated by using the polarization control unit and beam splitter, incorporating into the MRRs. In this work, frequency band of 10.7 MHz and 16 MHz and wavelengths of 206.9 nm, 1.448 µm, 2.169 µm and 2.489 µm can be obtained for QKD by using input optical soliton and Gaussian beam