Showing papers on "Data access published in 2009"

Secure and efficient access to outsourced data

Abstract: Providing secure and efficient access to large scale outsourced data is an important component of cloud computing. In this paper, we propose a mechanism to solve this problem in owner-write-users-read applications. We propose to encrypt every data block with a different key so that flexible cryptography-based access control can be achieved. Through the adoption of key derivation methods, the owner needs to maintain only a few secrets. Analysis shows that the key derivation procedure using hash functions will introduce very limited computation overhead. We propose to use over-encryption and/or lazy revocation to prevent revoked users from getting access to updated data blocks. We design mechanisms to handle both updates to outsourced data and changes in user access rights. We investigate the overhead and safety of the proposed approach, and study mechanisms to improve data access efficiency.

Motivating Online Publication of Data

Abstract: Despite policies and calls for scientists to make data available, this is not happening for most environmental- and biodiversity-related data because scientists' concerns about these efforts have not been answered and initiatives to motivate scientists to comply have been inadequate. Many of the issues regarding data availability can be addressed if the principles of “publication” rather than “sharing” are applied. However, online data publication systems also need to develop mechanisms for data citation and indices of data access comparable to those for citation systems in print journals.

Provenance Information in the Web of Data

Abstract: The openness of the Web and the ease to combine linked data from dierent sources creates new challenges. Systems that consume linked data must evaluate quality and trustworthiness of the data. A common approach for data quality assessment is the analysis of provenance information. For this reason, this paper discusses provenance of data on the Web and proposes a suitable provenance model. While traditional provenance research usually addresses the creation of data, our provenance model also represents data access, a dimension of provenance that is particularly relevant in the context of Web data. Based on our model we identify options to obtain provenance information and we raise open questions concerning the publication of provenance-related metadata for linked data on the Web.

Lifecycle management of facilities components using radio frequency identification and building information model

Abstract: The AECOO industry is highly fragmented; therefore, efficient information sharing and exchange between various players are evidently needed. Furthermore, the information about facility components should be managed throughout the lifecycle and be easily accessible for all players in the AECOO industry. BIM is emerging as a method of creating, sharing, exchanging and managing the information throughout the lifecycle between all the stakeholders. RFID, on the other hand, has emerged as an automatic data collection and information storage technology, and has been used in different applications in AECOO. This research proposes permanently attaching RFID tags to facility components where the memory of the tags is populated with accumulated lifecycle information of the components taken from a standard BIM database. This information is used to enhance different processes throughout the lifecycle. In addition, this research suggests storing other types of BIM information (e.g., floor plans) on RFID tags which is not necessarily related to the components themselves. Having BIM data chunks stored on tags provides a distributed database of BIM and allows data access for different players who do not have real-time access to a central database. In this research, a conceptual RFID-based system structure and data storage/retrieval design are elaborated. The value adding benefits and scope of impact of the proposed approach are discussed. To explore the technical feasibility of the proposed approach, two case studies have been implemented and tested.

Improving on-demand data access efficiency in MANETs with cooperative caching

Abstract: Mobile ad hoc networks (MANETs) provide an attractive solution for networking in the situations where network infrastructure or service subscription is not available. Its usage can further be extended by enabling communications with external networks such as the Internet or cellular networks through gateways. However, data access applications in MANETs suffer from dynamic network connections and restricted resources. While most of the research focuses on media (or medium) access control (MAC) and routing layer solutions, we explore the possibility of making use of data locality and the commonality in users' interests at the application level. In this paper, we investigate how cooperative caching can be used to improve data access efficiency in MANETs. We propose COOP, a novel cooperative caching scheme for on-demand data access applications in MANETs. The objective is to improve data availability and access efficiency by collaborating local resources of mobile nodes. COOP addresses two basic problems of cooperative caching: cache resolution and cache management. To improve data availability and access efficiency, COOP discovers data sources which induce less communication overhead by utilizing cooperation zones, historical profiles, and hop-by-hop resolution. For cache management, COOP increases the effective capacity of cooperative caches by minimizing caching duplications within the cooperation zone and accommodating more data varieties. The performance of COOP is studied using mathematical analysis and simulations from the perspectives of data availability, time efficiency, and energy efficiency. The analysis and simulation results show that COOP significantly reduces response delay and improves data availability with proper settings of the cooperation zone radius.

Development of a Community Hydrologic Information System

Abstract: Over the next decade, it is likely that science and engineering research will produce more scientific data than has been created over the whole of human history. The successful use of these data to achieve new scientific breakthroughs will depend on the ability to access, integrate, and analyze these large datasets. The way these data are organized and manipulated either enables or inhibits the analyses that can be performed. The Consortium of Universities for the Advancement of Hydrologic Science, Inc (CUAHSI) is developing information technology infrastructure to support advanced hydrologic analysis and education. The CUAHSI Hydrologic Information System (HIS) is an internet based system to support the sharing of hydrologic data. It is comprised of hydrologic databases and servers connected through web services as well as software for data publication, discovery and access. The HIS is founded upon an information model for observations at stationary points that supports its data services. The CUAHSI Observations Data Model (ODM) provides community defined semantics needed to allow sharing of hydrologic information. Following this uniform semantic model, CUAHSI HIS web services provide access to multiple disparate data sources: from national repositories such as the USGS National Water Information System (NWIS) and USEPA Storage and Retrieval System (STORET), to distributed databases published by academic researchers and community groups on their own servers in a standard format. These web services are registered to a central HIS website, where they become searchable and accessible through centralized discovery and data access tools. HIS utilizes both an XML and relational database schema for transmission and storage of data respectively. WaterML (Water Markup Language) is the XML schema used for data transmission that underlies machine to machine communications, while ODM is implemented as a relational database model for persistent data storage. Web services support access to hydrologic data stored in ODM or other repositories from application software such as Excel, MATLAB and ArcGIS that have Simple Object Access Protocol (SOAP) capability. HIS Desktop provides a local data repository and set of tools that also facilitates the integration and analysis processes. A significant value of both the web services and HIS desktop derives from the capability to use them from within a user's preferred analysis environment, using community defined semantics, rather than requiring a user to learn new software. This paper describes the technology and tools developed as part of the CUAHSI HIS that provide: (1) Data Storage in a relational data model (ODM); (2) Data Access through internet-based Water Data Services using a consistent data language, called WaterML; (3) Data Indexing through a National Water Metadata Catalog; and (4) Data Discovery through a federated map and thematic keyword search system. The combination of these capabilities creates a common window on water observations data for the United States unlike any that has existed before, and is also extensible worldwide.

Data replication protocols for mobile ad-hoc networks: a survey and taxonomy

Abstract: In mobile ad-hoc networks, frequent network partitioning and the failure of mobile nodes due to exhaustion of their battery power can considerably decrease data availability. In addition, the increase in network size and node mobility cause the performance of data access to degrade. To deal with these issues, a number of data replication protocols have been proposed in the recent years. This paper surveys the existing data replication protocols in mobile ad-hoc networks and proposes a classification scheme that categorizes the protocols into various classes, with respect to the issues they address. Network partitioning, energy consumption, and scalability are the three issues that are identified in this paper, and which have not been previously considered in the fixed networks. The paper also provides a comparison of the protocols and investigates opportunities for future research.

On analyzing and specifying concerns for data as a service

Abstract: Providing data as a service has not only fostered the access to data from anywhere at anytime but also reduced the cost of investment. However, data is often associated with various concerns that must be explicitly described and modeled in order to ensure that the data consumer can find and select relevant data services as well as utilize the data in the right way. In particular, the use of data is bound to various rules imposed by data owners and regulators. Although, technically Web services and database technologies allow us to quickly expose data sources as Web services, until now, research has not been focused on the description of data service concerns, thus hindering the discovery, selection and utilization of data services. In this paper, we analyze major concerns for data as a service, model these concerns, and discuss how they can be used to improve the search and utilization of data services.

Data Layout Transformation for Enhancing Data Locality on NUCA Chip Multiprocessors

Abstract: With increasing numbers of cores, future CMPs (Chip Multi-Processors) are likely to have a tiled architecture with a portion of shared L2 cache on each tile and a bank-interleaved distribution of the address space. Although such an organization is effective for avoiding access hot-spots, it can cause a significant number of non-local L2 accesses for many commonly occurring regular data access patterns. In this paper we develop a compile-time framework for data locality optimization via data layout transformation. Using a polyhedral model, the program's localizability is determined by analysis of its index set and array reference functions, followed by non-canonical data layout transformation to reduce non-local accesses for localizable computations. Simulation-based results on a 16-core 2D tiled CMP demonstrate the effectiveness of the approach. The developed program transformation technique is also useful in several other data layout transformation contexts.

MobiSense — mobile network services for coordinated participatory sensing

Abstract: Cellular and Wi-Fi networks now form a global substrate that provides billions of mobile phone users with consistent, location-aware communication and multimedia data access. On this substrate is emerging a new class of mobile phone applications that use the phones location, image and acoustic sensors, and enable people to choose what to sense and when to share data about themselves and their surroundings. Peoples' natural movement through and among living, work, and “third” spaces, provides spatial and temporal coverage for these modalities, the character of which is impossible to achieve through embedded instrumentation alone. This paper proposes a network service architecture for participatory sensing, describing challenges in (1) network coordination services enabling applications to efficiently select, incentivize and task mobile users based on measures of coverage, capabilities and interests; (2) attestation mechanisms to enable data consumers to assign trust to the data they access; and (3) participatory privacy regulation mechanisms used by data contributors to control what data they share.

mzAPI: a new strategy for efficiently sharing mass spectrometry data.

Abstract: To The Editor: The call for data access standards in mass spectrometry-based proteomics has led to proposals focused on the extraction of native data to XML-based formats. 1,2 While self-describing and human-readable formats represent laudable goals, particularly for archival purposes, they are not well suited to large numeric datasets. Consequently, while metadata in mzML2 remain human-readable, the vast majority of the file is devoted to a hexadecimal representation of the mass spectra. Moreover, the transition from mzXML to a true XML format (mzML2) eliminates embedded indexing schemes; consequently, extracted files are compromised in both content and access efficiency.1,3 Based on similarities in data structure and access patterns, we suggest that fields such as astronomy are better models for proteomics data analysis (Figure 1). These fields also rely on common formats, but typically utilize binary standards such as HDF54 or netCDF5. By contrast, the commercial nature of mass spectrometry has led to the evolution of proprietary binary file formats. In light of these observations, we propose that a common and redistributable application programming interface (API) represents a more viable approach to data access in mass spectrometry. In effect, we propose to shift the burden of standards compliance to the manufacturers’ existing data access libraries. Figure 1 Array Scanners, Telescopes, and Mass Spectrometers: XML, HDF, or API? While our proposal for abstraction through a common API represents a clear departure from current attempts to define a universal file format, it is by no means unique within the broader scientific community. For example, standardized APIs have enabled the development of portable applications in such diverse areas as computer graphics (OpenGL7) and parallel processing (Message Passing Interface, MPI8). More importantly, we believe that a common API will benefit all stakeholders. For example, free redistribution of compiled, vendor-supplied dynamically linked libraries (DLLs) will protect the proprietary layout of native files and provide users with direct and flexible access to data system- and instrument-specific functionality which are typically ignored by lowest common denominator export routines. In addition, we note that mzAPI naturally supports the FDA’s 21 CFR part 11 regulatory requirements for electronic records9 Finally, a community-driven API standard will facilitate manufacturer support of UNIX, in addition to Windows, by highlighting the subset of procedures, from each data system (Xcalibur™, Analyst™, etc.), which need to be ported. Motivated originally by our desire to provide a more intimate environment for flexible and in-depth exploration of mass spectrometry data, particularly from low-throughput experiments, we developed a preliminary common API (mzAPI) – consisting of just five procedures (http://blais.dfci.harvard.edu/mzAPI). To maximize accessibility we exposed mzAPI in the form of a Python library within a flexible, mass-informatics desktop framework called multiplierz (http://blais.dfci.harvard.edu/multiplierz). We are encouraged by results from this test harness, in particular how well mzAPI and our desktop environment support a variety of data analytic operations. Equally impressive is how quickly non-programmers can customize scripts for their specific tasks. Despite success to date in our own lab, we recognize that mzAPI will benefit from further refinement and stress testing. Accordingly, we are actively seeking input from the research community with respect to both concept and implementation of a comprehensive API-based standard for mass spectrometry data access and analysis.

Network data access method, access gateway and system capable of supporting sensor

Abstract: The invention provides a sensor network data access method, and an access gateway and a system thereof. The sensor networks are linked via gateways and IP network systems to support access to sensor network data. The access method comprises the following steps: (a) storing target access equipment information in a gateway; (b) searching the target access equipment information by the gateway when the gateway starts routing the sensor data from a sensor network linked with the gateway according to target node information of the sensor data; (c) carrying out IP data encapsulation of the sensor data with the obtained target access equipment information and sending to target access equipment via an IP network; and (d) decapsulating the received IP data packet by the target access equipment.

A Static Analysis Framework for Database Applications

Abstract: Database developers today use data access APIs such as ADO.NET to execute SQL queries from their application. These applications often have security problems such as SQL injection vulnerabilities and performance problems such as poorly written SQL queries. However today's compilers have little or no understanding of data access APIs or DBMS, and hence the above problems can go undetected until much later in the application lifecycle. We present a framework that adapts traditional program analysis by leveraging understanding of data access APIs in order to identify such problems early on during application development. Our framework can analyze database application binaries that use ADO.NET data access APIs. We show how our framework can be used for a variety of analysis tasks such as SQL injection detection, workload extraction, identifying performance problems, and verifying data integrity constraints in the application.

DP²AC: Distributed Privacy-Preserving Access Control in Sensor Networks

Abstract: The owner and users of a sensor network may be different, which necessitates privacy-preserving access control. On the one hand, the network owner need enforce strict access control so that the sensed data are only accessible to users willing to pay. On the other hand, users wish to protect their respective data access patterns whose disclosure may be used against their interests. This paper presents DP 2 AC, a Distributed Privacy- Preserving Access Control scheme for sensor networks, which is the first work of its kind. Users in DP 2 AC purchase tokens from the network owner whereby to query data from sensor nodes which will reply only after validating the tokens. The use of blind signatures in token generation ensures that tokens are publicly verifiable yet unlinkable to user identities, so privacy- preserving access control is achieved. A central component in DP 2 AC is to prevent malicious users from reusing tokens. We propose a suite of distributed techniques for token-reuse detection (TRD) and thoroughly compare their performance with regard to TRD capability, communication overhead, storage overhead, and attack resilience. The efficacy and efficiency of DP 2 AC are confirmed by detailed performance evaluations.

Data access programming model for occasionally connected applications

Abstract: Portions of a computing environment (such as a user's mesh) may restrict accessing to particular types of access by particular applications The computer may support applications executing within a virtual environment (such as a web browser) by brokering such access through a token-based system When an application requests a particular type of access (eg, writing to a particular data object), the computer may contact an authorization server with the credentials of the application to request the specified access, and may receive and store an authorization token The computer may then access the computing environment with the authorization token, and may return the results to the application within the virtual environment Additional features may further support such applications; eg, a programmatic interface may be provided in a familiar language, such as JavaScript, whereby applications can request access to particular data objects and identify authorized access capabilities

Recursive Computation of Regions and Connectivity in Networks

Abstract: In recent years, the data management community has begun to consider situations in which data access is closely tied to network routing and distributed acquisition: examples include, sensor networks that execute queries about reachable nodes or contiguous regions, declarative networks that maintain information about shortest paths and reachable endpoints, and distributed and peer-to-peer stream systems that detect associations (e.g., transitive relationships) among data at the distributed sources. In each case, the fundamental operation is to maintain a view over dynamic network state. This view is typically distributed, recursive, and may contain aggregation, e.g., describing transitive connectivity, shortest paths, least costly paths, or region membership.Surprisingly, solutions to computing such views are often domain-specific, expensive, and incomplete. In this paper, we recast the problem as one of incremental recursive view maintenance in the presence of distributed streams of updates to tuples: new stream data becomes insert operations and tuple expirations become deletions. We develop a set of techniques that maintain compact information about tuple derivability or data provenance. We complement this with techniques to reduce communication: aggregate selections to prune irrelevant aggregation tuples, provenance-aware operators that can determine when tuples are no longer derivable and remove them from their state, and shipping operators that greatly reduce the tuple and provenance information being propagated while still maintaining correct answers. We validate our work in a distributed setting with sensor and network router queries, showing significant gains in communication overhead without sacrificing performance.

Programming model for application and data access and synchronization within virtual environments

Abstract: Applications executing on computer systems may execute in a virtual environment, such as a web application executing in a web browser. An application may access the actual computing environment (such as the filesystem), but this accessing may be complicated; e.g., the computing environment may be deployed across many computers and devices, and may be synchronized for offline access via a local cache. A computing environment component may service the complex computing environment (e.g., by managing the cache and retrieving remotely stored data objects) and expose it as a well-organized set of data objects. A virtual environment interface (e.g., a web browser plug-in) may allow applications hosted in the virtual environment to access the computing environment through the computing environment component. Programmatic interfaces may also be implemented to permit such accessing via familiar programming languages and techniques, such as JavaScript libraries exposed to web applications in the web browser.

Information Processing Device and Method, Recording Medium, Program and Information Processing System

Abstract: An information processing device regarding which access to data held by the information processing device itself, in multiple regions, is requested from another information processing device, includes: an authenticating unit to perform authenticating processing of the other information processing device; a receiving unit to receive an access license ticket including an access code and a check digit; an access license ticket generating key generating unit to generate an access license ticket generating key, which is key information for computing a check digit using data held beforehand, a root key, an access control key, and other key information which is key information to manage data of a region other than the predetermined region, corresponding to an access code; check digit computing unit to compute a check digit corresponding to the access code described in the access license ticket; and access license ticket validating unit to validate the access license ticket.

RDF Storage and Retrieval Systems

Abstract: Ontologies are often used to improve data access. For this purpose, existing data has to be linked to an ontology and appropriate access mechanisms have to be provided. In this chapter, we review RDF storage and retrieval technologies as a common approach for accessing ontology-based data. We discuss different storage models, typical functionalities of RDF middleware such as data model support and reasoning capabilities and RDF query languages with a special focus on SPARQL as an emerging standard. We also discuss some trends such as support for expressive ontology and rule languages.

Automatic Extraction of Ontologies Wrapping Relational Data Sources

Abstract: Describing relational data sources (ie databases) by means of ontologies constitutes the foundation of most of the semantic based approaches to data access and integration In spite of the importance of the task this is mostly carried out manually and, to the best of our knowledge, not much research has been devoted to its automatisation In this paper we introduce an automatic procedure for building ontologies starting from the integrity constraints present in the relational sources Our work builds upon the wide literature on database schema reverse engineering; however, we adapt these techniques to the specific purpose of reusing the extracted schemata (or ontologies) in the context of semantic data access In particular, we ensure that the underlying data sources can be queried through the ontologies and the extracted ontologies can be used for semantic integration using recently developed techniques in this area In order to represent the extracted ontology we adopt a variant of the DLR-Lite description logic because of its ability to express the mostly used modelling constraints, and its nice computational properties The connection with the relational data sources is captured by means of sound views Moreover, the adoption of this formal language enables us to prove that the extracted ontologies preserve the semantics of the integrity constraints in the relational sources Therefore, there is no data loss, and the extracted ontology constitutes a faithful wrapper of the relational sources

Access control for graph data

Abstract: Systems, methods, and other embodiments associated with access control for graph data at the instance-level are described. One example method includes accepting data access constraints that are expressed as match and apply pattern pairs to enforce security policies. A user query on graph data with a security policy restricts the returned data to data that the user is authorized to access. For this purpose, a user query that includes query selection criteria corresponding to one or more match pattern criteria based on the resource referenced in the query is rewritten to include security conditions specified in the associated apply pattern to restrict access to the graph data.

Research Using Emergency Department–related Data Sets: Current Status and Future Directions

Abstract: The 2009 Academic Emergency Medicine consensus conference focused on “Public Health in the ED: Surveillance, Screening and Intervention.” One conference breakout session discussed the significant research value of health-related data sets. This article represents the proceedings from that session, primarily focusing on emergency department (ED)-related data sets and includes examples of the use of a data set based on ED visits for research purposes. It discusses types of ED-related data sets available, highlights barriers to research use of ED-related data sets, and notes limitations of these data sets. The paper highlights future directions and challenges to using these important sources of data for research, including identification of five main needs related to enhancing the use of ED-related data sets. These are 1) electronic linkage of initial and follow-up ED visits and linkage of information about ED visits to other outcomes, including costs of care, while maintaining deidentification of the data; 2) timely data access with minimal barriers; 3) complete data collection for clinically relevant and/or historical data elements, such as the external cause-of-injury code; 4) easy access to data that can be parsed into smaller jurisdictions (such as states) for policy and/or research purposes, while maintaining confidentiality; and 5) linkages between health survey data and health claims data. ED-related data sets contain much data collected directly from health care facilities, individual patient records, and multiple other sources that have significant potential impact for studying and improving the health of individuals and the population.

Methods of utilizing address mapping table to manage data access of storage medium without physically accessing storage medium and related storage controllers thereof

Abstract: A method of managing data access of a storage medium includes establishing an address mapping table to record a physical address of a first data stored in the storage medium, where the physical address of the first data is mapped to a logical address of the first data; and when receiving a command for handling the first data stored in the storage medium internally, processing the address mapping table to serve the command without physically accessing the first data stored in the storage medium.

Multi-tenancy data storage and access method and apparatus

Abstract: A method, apparatus, and a computer program product for storing and accessing multi-tenancy data The method includes the steps of: creating a plurality of table sets in one or more databases, wherein each table set is used to store data of a group of tenants selected from a plurality of tenants; accessing data of a tenant in a table set in response to receiving a data access request from the tenant; and recording relationships between the tenants and the table sets in a multi-tenancy metadata repository, wherein the step of accessing the data of the tenant comprises the steps of finding the table set by querying the metadata repository and accessing the data of the tenant in the table set based on the result received from the query of the metadata repository

Management of Access to Data Distributed Across Multiple Computing Devices

Abstract: Methods, systems and apparatus for a distributed data environment in which data can be seamlessly accessed from remote computing devices are disclosed. For a given user having multiple computing devices, a personal distributed data bank can be formed from data storage capacities resident at the multiple computing device. The given user can access data on any of the multiple computing devices without knowing on which of the multiple computing devices the data resides. In one embodiment, an index for the user's data within the personal distributed data bank can be provided to facilitate searching, browsing and accessing of user data by the given user.

Adaptive Scratch Pad Memory Management for Dynamic Behavior of Multimedia Applications

Abstract: Exploiting runtime memory access traces can be a complementary approach to compiler optimizations for the energy reduction in memory hierarchy. This is particularly important for emerging multimedia applications since they usually have input-sensitive runtime behavior which results in dynamic and/or irregular memory access patterns. These types of applications are normally hard to optimize by static compiler optimizations. The reason is that their behavior stays unknown until runtime and may even change during computation. To tackle this problem, we propose an integrated approach of software [compiler and operating system (OS)] and hardware (data access record table) techniques to exploit data reusability of multimedia applications in Multiprocessor Systems on Chip. Guided by compiler analysis for generating scratch pad data layouts and hardware components for tracking dynamic memory accesses, the scratch pad data layout adapts to an input data pattern with the help of a runtime scratch pad memory manager incorporated in the OS. The runtime data placement strategy presented in this paper provides efficient scratch pad utilization for the dynamic applications. The goal is to minimize the amount of accesses to the main memory over the entire runtime of the system, which leads to a reduction in the energy consumption of the system. Our experimental results show that our approach is able to significantly improve the energy consumption of multimedia applications with dynamic memory access behavior over an existing compiler technique and an alternative hardware technique.

Opaque Quarantine and Device Discovery

Abstract: Embodiments described herein provide communication control features and functionality, but are not so limited. In an embodiment, a computing environment includes an access control component that can use a number of access states to control access to computing data and/or services. In one embodiment, a server computer can control access to data and/or services using a number of access states including, but not limited to: an allowed state, a blocked state, a device discovery state, and/or a quarantined state. Other embodiments are available.

System, method and device for locally caching data

Abstract: A device (100) for controlling local caching of data available from a remote server (350) by identifying data sources that are repetitively accessed including a time and frequency of data access. A rate of updating the data source at the remote server is determined and the data from the data source is retrieved and stored in a local cache (140) based on the identified time and frequency of data access and the determined rate of updating the data source. The device may be arranged in a peer to peer configuration to distribute the stored data to a peer device that has an affinity to the stored data. The stored data may be distributed to peer devices based on an identified time and frequency of data access that is associated with the peer device.

Reasoning Web. Semantic Technologies for Information Systems: 5th International Summer School 2009, Brixen-Bressanone, Italy, August 30 - September 4, 2009, Tutorial Lectures

Abstract: This book contains a collection of seven thoroughly revised tutorial papers based on lectures given by leading researchers at the 5th International Summer School on the Reasoning Web, held in Brixen-Bressanone, Italy, from August 30 to September 4, 2009. The objective of the book is to provide a coherent introduction to semantic web methods and research issues with a particular emphasis on reasoning. The focus of this year s event was on the use of semantic technologies to enhance data access on the web. Topics covered include design and analysis of reasoning procedures for description logics; answer set programming basics, its modeling methodology and its principal extensions tailored for semantic web applications; languages for constraining and querying XML data; RDF database theory and efficient and scalable support for RDF/OWL data storage, loading, inferencing and querying; tractable description logics and their use for ontology-based data access; and the social semantic desktop, which defines a user s personal information environment as a source and end-point of the semantic web