Semantic-Web Technology: Applications at NASA

We provide a description of work at the National Aeronautics and Space Administration (NASA) on building systems based on Semantic-Web concepts and technologies. NASA has been one of the early adopters of Semantic-Web technologies for practical applications. Indeed there are several ongoing (IT) endeavors on building semantics based systems for use in diverse NASA domains ranging from collaborative scientific activity to accident and mishap investigation to enterprise search to scientific information gathering and integration to aviation safety decision support. We provide a brief overview of many applications and ongoing work with the goal of informing the external community of these NASA endeavors

Provenance Explorer: A Tool for Viewing Provenance Trails and Constructing Scientific Publication Packages

This paper presents Provenance Explorer, a secure provenance visualization tool, designed to dynamically generate customized views of scientific data provenance that depend on the viewer's requirements and/or access privileges. Using RDF and graph visualizations, it enables scientists to view the data, states and events associated with a scientific workflow in order to understand the scientific methodology and validate the results. Initially the Provenance Explorer presents a simple, coarse-grained view of the scientific process or experiment. However the GUI allows permitted users to expand links between nodes (input states, events and output states) to reveal more fine-grained information about particular sub-events and their inputs and outputs. Access control is implemented using Shibboleth to identify and authenticate users and XACML to define access control policies. The system also provides a platform for publishing scientific results. It enables users to select particular nodes within the visualized workflow and drag-and-drop them into an RDF package for publication or e-learning. The direct relationships between the individual components selected for such packages are inferred by the rule inference engine

Provenance explorer: Customized provenance views using semantic inferencing

This paper presents Provenance Explorer, a secure provenance visualization tool, designed to dynamically generate customized views of scientific data provenance that depend on the viewer's requirements and/or access privileges. Using RDF and graph visualizations, it enables scientists to view the data, states and events associated with a scientific workflow in order to understand the scientific methodology and validate the results. Initially the Provenance Explorer presents a simple, coarse-grained view of the scientific process or experiment. However the GUI allows permitted users to expand links between nodes (input states, events and output states) to reveal more fine-grained information about particular sub-events and their inputs and outputs. Access control is implemented using Shibboleth to identify and authenticate users and XACML to define access control policies. The system also provides a platform for publishing scientific results. It enables users to select particular nodes within the visualized workflow and drag-and-drop them into an RDF package for publication or e-learning. The direct relationships between the individual components selected for such packages are inferred by the rule-inference engine

Context-aware system applied in industrial assembly environment

The objective of this paper is to present an ongoing development of a context-aware system used within industrial environments. The core of the system is so-called Cognitive Model for Robot Group Control. This model is based on well-known concepts of Ubiquitous Computing, and is used to control robot behaviours in specially designed industrial environments. By using sensors integrated within the environment, the system is able to track and analyse changes, and update its informational buffer appropriately. Based on freshly collected information, the Model is able to provide a transformation of high-level contextual information to lower-level information that is much more suitable and understandable for technical systems. The Model uses semantically defined knowledge to define domain of interest, and Bayesian Network reasoning to deal with the uncertain events and ambiguity scenarios that characterize our naturally unstructured world

Social Network Analysis on Educational Data Set in RDF Format

The increased usage of information technologies in educational tasks resulted in high volume of data, exploited to build analytical systems that can provide practical insight in the learning process. In this paper, we propose a method of running social network analysis on multiple data sources (academic years, communication tools). To achieve this, the collected data that describe social interactions were converted into a common format by employing a prior developed semantic web educational ontology. Using a mapping language the relational data set was linked to the appropriate concepts defined in the ontology and then it was exported in RDF format. The means for SPARQL access was also provided. Subsequently, query patterns were defined for different social interactions in the educational platform. To prove the feasibility of this approach, Gephi tool set was used to run SNA (Social Network Analysis) on data obtained with the SPARQL queries. The added value of this research lies in the potential of this method to simplify running social network analysis on multiple data sets, on a specific course or the entire academic year, by simply modifying the query pattern

Semantic Web Service Engineering: Annotation Based Approach

Web services are an emerging paradigm which aims at implementing software components in the Web. They are based on syntactic standards, notably WSDL. Semantic annotation of Web services provides better qualitative and scalable solutions to the areas of service interoperation, service discovery, service composition and process orchestration. Manual annotation is a time-consuming process which requires deep domain knowledge and consistency of interpretation within annotation teams. Therefore, we propose an approach for semi-automatically annotating WSDL Web services descriptions. This is allowed by Semantic Web Service Engineering. The annotation approach consists of two main processes: categorization and matching. Categorization process consists in classifying WSDL service description to its corresponding domain. Matching process consists in mapping WSDL entities to pre-existing domain ontology. Both categorization and matching rely on ontology matching techniques. A tool has been developed and some experiments have been carried out to evaluate the proposed approach

Configuration of service oriented architectures with semantic technologies based on non-functional requirements

Ова дисертација је фокусирана на примену семантичких технологија за решавање проблема оптималне конфигурације сервисно-оријентисаних архитектура (енгл. Service Oriented Architecture – SOA) на основу нефункционалних захтева корисника. Решење је базирано на проширењу АHP алгоритма за рад са различитим врстама захтева и развоју хеуристичког приступа заснованог на генетичким алгоритмима за решавање проблема оптималне конфигурације. Постојећа решења у овој области су показала изузетно мали ниво персонализације, тј корисницима није дозвољено дефинисање разних софистициранијих врста захтева који осликавају њихове жеље, очекивања и строге захтеве за које захтевају потпуно испуњење. Такође, постојећа решења су била перманентно фокусирана на испуњење захтева функционалности, након чега се врши одабир конфигурације сходно захтевима о смањењу вредности карактеристика које имају тенденцију раста (нпр., цена и време извршавања), односно повећању вредности карактеристика које имају тенденцију опадања (нпр., поузданост и доступност). Међутим, када се посматрају целе фамилије SOA, од посебног значаја постаје проблем конструкције конфигурације при истовременом задовољењу функционалних и нефункционалних захтева. Предложено интегрално решење под називом OptConfSOAFобезбеђује представљање различитих врста захтева (безусловни, условни, захтеви о лексикографском поретку) о нефункционалним карактеристикама и оптималну конфигурацију фамилија SOA на основу дефинисаних захтева. Приступ који се предлаже обезбеђује истовремено задовољење захтева који се тичу функционалности система као и нефункционалних захтева који могу бити различитог нивоа приоритета, односити се на поједине делове или сервисно- оријентисану архитектуру у целости. Предложено решење је опште и није ограничено само на веб сервисе, иако се појам семантичких технологија обично везује за дати домен примене. Решење се може применити у било ком домену у којем се SOA парадигма може применити посматрањем сервиса као било које компоненте (необавезно софтверске) дате функционалности...This dissertation is focused on the application of semantic technologies for solving the problem of optimal configuration of service-oriented architectures (SOA) based on stakeholders’ non-functional requirements. The proposed solution is developed as an extension of the AHP algorithm to allow for processing of different kinds of requirements. To address the problem of optimal configuration of SOA, a heuristic approach based on genetic algorithms has also been proposed and validated. Existing approaches in this field have shown low level of personalization, i.e. stakeholders are neither enabled to define sophisticated requirements that reflect their own expectations and attitudes, nor they are able to indicate hard requirements that have to be fully satisfied. Furthermore, existing approaches were primarily addressing the problem of fulfilling functional requirements, while the selection of an appropriate configuration is driven by the goal of decreasing the values of monotonically decreasing features (e.g., price and execution time) and simultaneous increasing the values of monotonically increasing features (e.g., availability and reliability). By considering the whole SOA families, the problem of configuration based on both functional and nonfunctional requirements gets special importance for research and further applications. The proposed solution, titled OptConfSOAF provides a framework for specification and processing of different kinds of requirements (unconditional, conditional, and requirements about lexicographical order) over non-functional features, and further optimal configuration of SOA families. The proposed approach provides simultaneous fulfillment of functional requirements (i.e., requirements related to the system’s functionalities) and non-functional requirements, where the latter could be defined with different level of importance, for specific parts of a SOA-based system or the system in its entirety. The proposed solution is general and is not bound to web services, even though semantic technologies are often associated with that domain. Since the solution considers a service as a component (no mandatory to be software component) with the specified functionality, it is applicable and easily adaptable to any specific application domain where SOA paradigm may be applied..