12,407 research outputs found
XML document design via GN-DTD
Designing a well-structured XML document is important for the sake of readability and maintainability. More importantly, this will avoid data redundancies and update anomalies when maintaining a large quantity of XML based documents. In this paper, we propose a method to improve XML structural design by adopting graphical notations for Document Type Definitions (GN-DTD), which is used to describe the structure of an XML document at the schema level. Multiples levels of normal forms for GN-DTD are proposed on the basis of conceptual model approaches and theories of normalization. The normalization rules are applied to transform a poorly designed XML document into a well-designed based on normalized GN-DTD, which is illustrated through examples
Safe abstractions of data encodings in formal security protocol models
When using formal methods, security protocols are usually modeled at a high level of abstraction. In particular, data encoding and decoding transformations are often abstracted away. However, if no assumptions at all are made on the behavior of such transformations, they could trivially lead to security faults, for example leaking secrets or breaking freshness by collapsing nonces into constants. In order to address this issue, this paper formally states sufficient conditions, checkable on sequential code, such that if an abstract protocol model is secure under a Dolev-Yao adversary, then a refined model, which takes into account a wide class of possible implementations of the encoding/decoding operations, is implied to be secure too under the same adversary model. The paper also indicates possible exploitations of this result in the context of methods based on formal model extraction from implementation code and of methods based on automated code generation from formally verified model
Recovering Grammar Relationships for the Java Language Specification
Grammar convergence is a method that helps discovering relationships between
different grammars of the same language or different language versions. The key
element of the method is the operational, transformation-based representation
of those relationships. Given input grammars for convergence, they are
transformed until they are structurally equal. The transformations are composed
from primitive operators; properties of these operators and the composed chains
provide quantitative and qualitative insight into the relationships between the
grammars at hand. We describe a refined method for grammar convergence, and we
use it in a major study, where we recover the relationships between all the
grammars that occur in the different versions of the Java Language
Specification (JLS). The relationships are represented as grammar
transformation chains that capture all accidental or intended differences
between the JLS grammars. This method is mechanized and driven by nominal and
structural differences between pairs of grammars that are subject to
asymmetric, binary convergence steps. We present the underlying operator suite
for grammar transformation in detail, and we illustrate the suite with many
examples of transformations on the JLS grammars. We also describe the
extraction effort, which was needed to make the JLS grammars amenable to
automated processing. We include substantial metadata about the convergence
process for the JLS so that the effort becomes reproducible and transparent
First-Class Functions for First-Order Database Engines
We describe Query Defunctionalization which enables off-the-shelf first-order
database engines to process queries over first-class functions. Support for
first-class functions is characterized by the ability to treat functions like
regular data items that can be constructed at query runtime, passed to or
returned from other (higher-order) functions, assigned to variables, and stored
in persistent data structures. Query defunctionalization is a non-invasive
approach that transforms such function-centric queries into the data-centric
operations implemented by common query processors. Experiments with XQuery and
PL/SQL database systems demonstrate that first-order database engines can
faithfully and efficiently support the expressive "functions as data" paradigm.Comment: Proceedings of the 14th International Symposium on Database
Programming Languages (DBPL 2013), August 30, 2013, Riva del Garda, Trento,
Ital
Authorised Translations of Electronic Documents
A concept is proposed to extend authorised translations of documents to
electronically signed, digital documents. Central element of the solution is an
electronic seal, embodied as an XML data structure, which attests to the
correctness of the translation and the authorisation of the translator. The
seal contains a digital signature binding together original and translated
document, thus enabling forensic inspection and therefore legal security in the
appropriation of the translation. Organisational aspects of possible
implementation variants of electronic authorised translations are discussed and
a realisation as a stand-alone web-service is presented.Comment: In: Peer-reviewed Proceedings of the Information Security South
Africa (ISSA) 2006 From Insight to Foresight Conference, 5 to 7 July 2006,
Sandton, South Afric
Digital Preservation Services : State of the Art Analysis
Research report funded by the DC-NET project.An overview of the state of the art in service provision for digital preservation and curation. Its focus is on the areas where bridging the gaps is needed between e-Infrastructures and efficient and forward-looking digital preservation services. Based on a desktop study and a rapid analysis of some 190 currently available tools and services for digital preservation, the deliverable provides a high-level view on the range of instruments currently on offer to support various functions within a preservation system.European Commission, FP7peer-reviewe
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