XML Elements Research Articles

Security Improvement of Xml Files Using Structure Modification

XML is an extensible markup language, with its influential explanatory, scalable, ordered, platform- independent features are widely used in the presence of a large number of e-commerce and e-business data exchange.XML is also broadly used in current distributed systems. The security of the XML based communication, and the Web services themselves, is of great implication to the overall security of these systems. Moreover, in order to assist interoperability, the security mechanisms should preferably be based on established standards. Encryption provides confidentiality by protecting sensitive information from being read by intruders. In this paper, we present one approach for encrypting xml file using separation of xml data and content of xml element.

Summarisation of the logical structure of XML documents

Summarisation is traditionally used to produce summaries of the textual contents of documents. In this paper, it is argued that summarisation methods can also be applied to the logical structure of XML documents. Structure summarisation selects the most important elements of the logical structure and ensures that the user’s attention is focused towards sections, subsections, etc. that are believed to be of particular interest. Structure summaries are shown to users as hierarchical tables of contents. This paper discusses methods for structure summarisation that use various features of XML elements in order to select document portions that a user’s attention should be focused to. An evaluation methodology for structure summarisation is also introduced and summarisation results using various summariser versions are presented and compared to one another. We show that data sets used in information retrieval evaluation can be used effectively in order to produce high quality (query independent) structure summaries. We also discuss the choice and effectiveness of particular summariser features with respect to several evaluation measures.

Result‐reconstruction method to return useful XML elements

PurposeNowadays there are a large number of XML documents on the web. This means that information retrieval techniques for searching XML documents are very important and necessary for internet users. Moreover, it is often said that users of search engines want to browse only relevant content in each document. Therefore, an effective XML element search aims to produce only the relevant elements or portions of an XML document. Based on the demand by users, the purpose of this paper is to propose and evaluate a method for obtaining more accurate search results in XML search.Design/methodology/approachThe existing approaches generate a ranked list in descending order of each XML element's relevance to a search query; however, these approaches often extract irrelevant XML elements and overlook more relevant elements. To address these problems, the authors' approach extracts the relevant XML elements by considering the size of the elements and the relationships between the elements. Next, the authors score the XML elements to generate a refined ranked list. For scoring, the authors rank high the XML elements that are the most relevant to the user's information needs. In particular, each XML element is scored using the statistics of its descendant and ancestor XML elements.FindingsThe experimental evaluations show that the proposed method outperforms BM25E, a conventional approach, which neither reconstructs XML elements nor uses descendant and ancestor statistics. As a result, the authors found that the accuracy of an XML element search can be improved by reconstructing the XML elements and emphasizing the informative ones by applying the statistics of the descendant XML elements.Research limitations/implicationsThis work focused on the effectiveness of XML element search and the authors did not consider the search efficiency in this paper. One of the authors' next challenges is to reduce search time.Originality/valueThe paper proposes a method for improving the effectiveness of XML element search.

Decision-cache based XACML authorisation and anonymisation for XML documents

This paper describes a decision cache for the eXtensible Access Control Markup Language (XACML) that supports fine-grained authorisation and anonymisation of XML based messages and documents down to XML attribute and element level. The decision cache is implemented as an XACML obligation service, where a specification of the XML elements to be authorised and anonymised is sent to the Policy Enforcement Point (PEP) during initial authorisation. Further authorisation of individual XML elements according to the authorisation specification is then performed on all matching XML resources, and decisions are stored in the decision cache. This makes it possible to cache fine-grained XACML authorisation and anonymisation decisions, which reduces the authorisation load on the Policy Decision Point (PDP). The theoretical solution is related to a practical case study consisting of a privacy-enhanced intrusion detection system that needs to perform anonymisation of Intrusion Detection Message Exchange Format (IDMEF) XML messages before they are sent to a security operations centre that operates in privacy-preserving mode. The solution increases the scalability of XACML based authorisation significantly, and may be instrumental in implementing federated authorisation and anonymisation based on XACML in several areas, including intrusion detection systems, web services, content management systems and GRID based authentication and authorisation.

Information Hiding in SOAP Messages: A Steganographic Method for Web Services

Digital steganography is the art and science of hiding communications; a steganographic system thus embeds secret data in public cover media so as not to arouse an eavesdropper’s suspicion. Hence, it is a kind of covert communication and information security. There are still very limited methods of steganography to be used with communication protocols, which represent unconventional but promising steganography mediums. In this paper, we discuss and analyze a number of steganographic studies in text, XML as well as SOAP messages. Then, we propose a novel steganography method to be used for SOAP messages within Web services environments. The method is based on rearranging the order of specific XML elements according to a secret message. This method has a high imperceptibility; it leaves almost no trail because of using the communication protocol as a cover medium, and since it keeps the structure and size of the SOAP message intact. The method is empirically validated using a feasible scenario so as to indicate its utility and value.

The SQL Function XMLNEST to Generate Recursive XML Values from Relational Data

SQL standard provides SQL/XML publishing functions to publish the result of an SQL query as XML values but it does not provide any SQL/XML publishing function that can publish the result of a recursive SQL query as recursively structured XML values. Therefore, to publish transitively connected relational tuples as recursively structured XML values with the use of appropriate SQL/XML publishing functions, we have to write a nested SQL query. Writing that query, however, is not easy provided that the depth of the connections is deep even if we know the depth of them and is not possible once the depth of the connections is not known in advance. To solve the problem, we propose a new SQL function XMLNEST that can publish the result of a recursive SQL query as recursively structured XML values. Both the recursive structure and the order of sibling XML elements of the XML values can be specified in the invocation of XMLNEST. Our experiments show that the proposed scheme will be the unique reasonable solution to the problem.

The ProteoRed MIAPE web toolkit: A User-friendly Framework to Connect and Share Proteomics Standards

The development of the HUPO-PSI's (Proteomics Standards Initiative) standard data formats and MIAPE (Minimum Information About a Proteomics Experiment) guidelines should improve proteomics data sharing within the scientific community. Proteomics journals have encouraged the use of these standards and guidelines to improve the quality of experimental reporting and ease the evaluation and publication of manuscripts. However, there is an evident lack of bioinformatics tools specifically designed to create and edit standard file formats and reports, or embed them within proteomics workflows. In this article, we describe a new web-based software suite (The ProteoRed MIAPE web toolkit) that performs several complementary roles related to proteomic data standards. First, it can verify that the reports fulfill the minimum information requirements of the corresponding MIAPE modules, highlighting inconsistencies or missing information. Second, the toolkit can convert several XML-based data standards directly into human readable MIAPE reports stored within the ProteoRed MIAPE repository. Finally, it can also perform the reverse operation, allowing users to export from MIAPE reports into XML files for computational processing, data sharing, or public database submission. The toolkit is thus the first application capable of automatically linking the PSI's MIAPE modules with the corresponding XML data exchange standards, enabling bidirectional conversions. This toolkit is freely available at http://www.proteored.org/MIAPE/.

A purpose‐based access control in native XML databases

SUMMARYWith the growing importance of privacy in data access, much research has been done on the privacy protecting technology in the recent years. Developing an access control model and related mechanisms to support a selective access data has become important. The extensible markup language (XML) is rapidly emerging as the new standard language for semi‐structured data representation and exchange on the Internet with more and more information being distributed in XML format. In this paper, we present a comprehensive approach for privacy preserving access control based on the notion of purpose. In our model, purpose information associated with a given data element in an XML document specifies the intended use of the data elements. An important issue addressed in this paper is the granularity of data labeling for data elements in XML documents and tree databases with which purposes can be associated. We address this issue in native XML databases and propose different labeling schemes for XML documents. We also propose an approach to represent purpose information to support access control based on purpose information. Our proposed solution relies on usage access control models as well as the components that are based on the notions of the purpose information used in subjects and objects. Finally, comparisons with related works are analysed. Copyright © 2011 John Wiley & Sons, Ltd.

Contextualization models for XML retrieval

In a hierarchical XML structure, surrounding elements form the context of an XML element. In document-oriented XML, the context is a part of the semantics of the element and augments its textual information. The process of taking the context of the element into account in element scoring is called contextualization. This study extends the concept of contextualization and presents a classification of contextualization models. In an XML collection, elements are of different granularity, i.e. lower level elements are shorter and carry less textual information. Thus, it seems credible that contextualization interacts differently with diverse elements. Even if it is known that contextualization leads to improved effectiveness in element retrieval, the improvement on different granularity levels has not been investigated. This study explores the effect of contextualization on these levels. Further, a parameterized framework for testing contextualization is presented. The empirical part of the study is carried out in a traditional laboratory setting, where an XML collection is granulated. This is necessary in order to measure performance separately at different hierarchy levels. The results confirm the effectiveness of contextualization, and show how the elements of different granularities benefit from contextualization.

XML Labeling Schemes for Dynamic Updates: Strengths and Limitations

The importance of XML processing has become a significant field at present days with the intention to support user queries in the most proficient way. In conjunction with this, many labeling schemes were proposed to identify the elements in XML document uniquely as well as preserve structural relationships among the nodes to cater queries with multiple combinations. On the other hand, due to the flexible structure of XML document, the data that is presented and communicated through this technology changes frequently. Therefore, labeling scheme must be able to support dynamic updates so that the existing labels do not require alteration. In this paper, we present some of the existing labeling techniques and their degree of support for structural relationship and dynamic updates.

Clinical map document based on XML (cMDX): document architecture with mapping feature for reporting and analysing prostate cancer in radical prostatectomy specimens

BackgroundThe pathology report of radical prostatectomy specimens plays an important role in clinical decisions and the prognostic evaluation in Prostate Cancer (PCa). The anatomical schema is a helpful tool to document PCa extension for clinical and research purposes. To achieve electronic documentation and analysis, an appropriate documentation model for anatomical schemas is needed. For this purpose we developed cMDX.MethodsThe document architecture of cMDX was designed according to Open Packaging Conventions by separating the whole data into template data and patient data. Analogue custom XML elements were considered to harmonize the graphical representation (e.g. tumour extension) with the textual data (e.g. histological patterns). The graphical documentation was based on the four-layer visualization model that forms the interaction between different custom XML elements. Sensible personal data were encrypted with a 256-bit cryptographic algorithm to avoid misuse. In order to assess the clinical value, we retrospectively analysed the tumour extension in 255 patients after radical prostatectomy.ResultsThe pathology report with cMDX can represent pathological findings of the prostate in schematic styles. Such reports can be integrated into the hospital information system. "cMDX" documents can be converted into different data formats like text, graphics and PDF. Supplementary tools like cMDX Editor and an analyser tool were implemented. The graphical analysis of 255 prostatectomy specimens showed that PCa were mostly localized in the peripheral zone (Mean: 73% ± 25). 54% of PCa showed a multifocal growth pattern.ConclusionscMDX can be used for routine histopathological reporting of radical prostatectomy specimens and provide data for scientific analysis.

Secure XML querying based on authorization graphs

XML is rapidly emerging as a standard for data representation and exchange over the World Wide Web and an increasing amount of sensitive business data is processed in XML format. Therefore, it is critical to have control mechanisms to restrict a user to access only the parts of XML documents that she is authorized to access. In this paper, we propose the first DTD-based access control model that employs graph matching to analyze if an input query is fully acceptable, fully rejectable, or partially acceptable. In this way, there will be no further security overhead for the processing of fully acceptable and rejectable queries. For partially acceptable queries, we propose a graph-matching based authorization model for an optimized rewriting procedure in which a recursive query (query with descendant axis `//') will be rewritten into an equivalent recursive one if possible and into a non-recursive one only if necessary, resulting queries that can fully take advantage of structural join based query optimization techniques. Moreover, we propose an index structure for XML element types to speed up the query rewriting procedure, a facility that is potentially useful for applications with large DTDs. Our performance study results showed that our algorithms armed with rewriting indexes are promising.

Achieving high output quality under limited resources through structure-based spilling in XML streams

Because of high volumes and unpredictable arrival rates, stream processing systems are not always able to keep up with input data - resulting in buffer overflow and uncontrolled loss of data. To produce eventually complete results, load spilling, which pushes some fractions of data to disks temporarily, is commonly employed in relational stream engines. In this work, we now introduce "structure-based spilling", a spilling technique customized for XML streams by considering the partial spillage of possibly complex XML elements. Such structure-based spilling brings new challenges. When a path is spilled, multiple paths may be affected. We analyze possible spilling effects on the query paths and how to execute the "reduced" query to produce partial results. To select the reduced query that maximizes output quality, we develop three optimization strategies, namely, OptR, OptPrune and ToX. We also examine the clean-up stage to guarantee that an entire result set is eventually generated by producing supplementary results. Our experimental study demonstrates that our proposed solutions consistently achieve higher quality results compared to the state-of-the-art techniques.

Adaptive Structural Index for Efficient Processing of XML Path Queries

This paper proposes an adaptive structural index: AS-Index (adaptive structural index), which can avoid the problem of the existing indexes. AS-Index is based on F&B-Index. It consists of F&B-Index, Query-Table and Part-Table. Frequent queries are kept in Query-Table avoiding redundant operations in query processing. Based on Query-Table an efficient bottom-up query processing is also proposed for answering infrequent queries using the frequent queries in Query-Table. Part-Table is used for optimizing the queries with descendant edges. The existing adaptive structural indexes need to traverse the whole document for adaptation, and their adaptation granularity is XML element node. For AS-Index, the adaptation granularity is F&B-Index node which includes a set of XML element nodes, and its adaptation is an efficient and incremental process that supports branch queries. The experimental results demonstrate that this index significantly outperforms the previous structural indexes in terms of query processing and adaptation efficiencies. For large XML documents, compared with the existing adaptive

Relevance feedback revisited: dealing with content and structure in XML documents

Relevance feedback (RF) is a technique that allows to enrich an initial query according to the user feedback. The goal is to express more precisely the user’s needs. Some open issues arise when considering semi-structured documents like XML documents. They are mainly related to the form of XML documents which mix content and structure information and to the new granularity of information. Indeed, the main objective of XML retrieval is to select relevant elements in XML documents instead of whole documents. Most of the RF approaches proposed in XML retrieval are simple adaptation of traditional RF to the new granularity of information. They usually enrich queries by adding terms extracted from relevant elements instead of terms extracted from whole documents. In this article, we describe a new approach of RF that takes advantage of two sources of evidence: the content and the structure. We propose to use the query term proximity to select terms to be added to the initial query and to use generic structures to express structural constraints. Both sources of evidence are used in different combined forms. Experiments were carried out within the INEX evaluation campaign and results show the effectiveness of our approaches.

Element Retrieval Using Namespace Based on Keyword Search over XML Documents

Querying over XML elements using keyword search is steadily gaining popularity. The traditional similarity measure is widely employed in order to effectively retrieve various XML documents. A number of authors have already proposed different similarity-measure methods that take advantage of the structure and content of XML documents. However, they do not consider the similarity between latent semantic information of element texts and that of keywords in a query. Although many algorithms on XML element search are available, some of them have the high computational complexity due to searching for a huge number of elements. In this paper, we propose a new algorithm that makes use of the se-mantic similarity between elements instead of between entire XML documents, considering not only the structure and content of an XML document, but also semantic information of namespaces in elements. We compare our algorithm with the three other algorithms by testing on real datasets. The experiments have demonstrated that our proposed method is able to improve the query accuracy, as well as to reduce the running time.

SAIL: Structure-aware indexing for effective and progressive top- k keyword search over XML documents

Keyword search in XML documents has recently gained a lot of research attention. Given a keyword query, existing approaches first compute the lowest common ancestors (LCAs) or their variants of XML elements that contain the input keywords, and then identify the subtrees rooted at the LCAs as the answer. In this the paper we study how to use the rich structural relationships embedded in XML documents to facilitate the processing of keyword queries. We develop a novel method, called SAIL, to index such structural relationships for efficient XML keyword search. We propose the concept of minimal-cost trees to answer keyword queries and devise structure-aware indices to maintain the structural relationships for efficiently identifying the minimal-cost trees. For effectively and progressively identifying the top- k answers, we develop techniques using link-based relevance ranking and keyword-pair-based ranking. To reduce the index size, we incorporate a numbering scheme, namely schema-aware dewey code, into our structure-aware indices. Experimental results on real data sets show that our method outperforms state-of-the-art approaches significantly, in both answer quality and search efficiency.

Using topic shifts in content-oriented XML retrieval

Content-oriented XML retrieval systems support access to XML repositories by retrieving, in response to user queries, XML document components (XML elements) instead of whole documents. The retrieved XML elements should not only contain information relevant to the query, but also should be specific to the given query (i.e. do not discuss other irrelevant topics). To score XML elements according to how relevant and specific they are given a query, the content and logical structure of XML documents have been widely used. This thesis aims to examine a new source of evidence deriving from the semantic decomposition of XML documents. We consider that XML documents can be semantically decomposed through the application of a topic segmentation algorithm. Using the semantic decomposition and the logical structure of XML documents, we define the notion of topic shifts in an XML element. We then formalise the number of topic shifts to reflect the element's relevance, and more particularly its specificness, to the given user's query. This thesis investigates the use of topic shifts in content-oriented XML retrieval, which is mainly involved in retrieving information from semi-structured (XML) documents. First, we examine the characteristics of XML elements reflected by their number of topic shifts. Second, we use the number of topic shifts to estimate the relevance of the elements in the collection. Finally, we use topic shifts to provide a focused access to XML documents, which aims to determine not only relevant elements, but those at the right level of granularity. The main contributions of this thesis are the introduction of topic shifts in the context of content-oriented XML retrieval and the extensive evaluation of the ways this evidence can be employed in retrieving XML elements. This thesis demonstrates that topic shifts in XML elements constitute a useful source of evidence for both improving the ranking of XML elements, and determining elements at the right level of granularity in content-oriented XML retrieval. The thesis is available online at http://elham.ashoori.org/publications/phd-thesis.pdf.

Content and structure summarisation for accessing XML documents

As the availability of structured documents is constantly increasing, retrieval systems able to return document portions are being developed. Structured documents, usually formatted in XML, may consist of large numbers of document portions, often organised into a hierarchical logical structure. With the high number of document portions, it is necessary to direct the attention of users of retrieval systems towards the most important document portions, and also, to give overviews of the structure of documents, in other words, to show document portions in context. This thesis investigates summarisation as a means to help searchers of XML retrieval systems in the process of accessing the contents of document portions. Two types of summarisation are investigated. First, summaries of the textual contents of document portions, called XML elements, are studied in a user-based environment. Traditionally, summarisation is associated with whole documents or document sets, but rarely with document portions. As summaries of documents have been proved to be useful in whole document retrieval, it is considered worthwhile to investigate summaries of document portions in XML element retrieval. Summaries of elements are presented to searchers in the context of other elements from the document. The textual summaries of elements also reflect the searchers' information needs: they are query based. The second type of summarisation investigated in this thesis is called structure summarisation. The automatic generation of tables of contents, as structure summaries, is described and examined. ToC generation is studied either when searchers' queries are available (query based structure summarisation) or otherwise (query independent structure summarisation). The work presented in this thesis has made several contributions to the fields of summarisation and interactive XML retrieval. The thesis is available online at http://www.dcs.qmul.ac.uk/~zolley/thesis.html.

Reverse Engineering from an XML Document into an Extended DTD Graph

Extensible markup language (XML) has become a standard for persistent storage and data interchange via the Internet due to its openness, self-descriptiveness, and flexibility. This article proposes a systematic approach to reverse engineer arbitrary XML documents to their conceptual schema–extended DTD graphs?which is a DTD graph with data semantics. The proposed approach not only determines the structure of the XML document, but also derives candidate data semantics from the XML element instances by treating each XML element instance as a record in a table of a relational database. One application of the determined data semantics is to verify the linkages among elements. Implicit and explicit referential linkages are among XML elements modeled by the parent-children structure and ID/IDREF(S) respectively. As a result, an arbitrary XML document can be reverse engineered into its conceptual schema in an extended DTD graph format.