Ákos Hajnal

Engineering web service invocations from agent systems

This paper presents a methodology that helps to bridge the gap between the theoretical foundations of agent technologies and their potential for industry-wide deployment. Agent systems are very often developed on top of a legacy system where agents have to be able to access the legacy system, usually web services, through a non-agent protocol and they have to be able to communicate with each other using an agent language. The methodology shows how existing web services can be integrated into agent systems. We have implemented tools to support the application of the methodology to mass amount of web service applications and a sample application to demonstrate the usage of the methodology and the supporting tools.

An applicable test data generation algorithm for domain errors

An integrated testing criterion is proposed that extends traditional criteria to be effective to reveal domain errors. The method requires many fewer test cases and is applicable for any kind of predicates. An automated test data generation algorithm is developed to satisfy the criterion. This is the first integrated algorithm that unites path selection and test data generation. The method is based on function minimization and is extended to find required test cases corresponding to ON-OFF points very quickly. In this way the algorithm is dynamic and thus can be used in practice.

A demand-driven approach to slicing legacy COBOL systems

Maintenance of aging legacy COBOL systems is labor‐intensive and is becoming a more and more difficult problem. Program slicing is a potentially useful analysis for aiding different maintenance activities, including program comprehension, reverse engineering, debugging, and testing. Numerous techniques have been proposed in the past decades; however, in interactive contexts, we found none of them suitable for slicing industrial‐scale COBOL systems due to their large space or preprocessing requirements. This paper proposes a novel static program slicing approach, which is based on context‐sensitive token propagation over control flow graphs (CFGs). CFGs require less space compared with program dependence graphs (PDGs) used by other techniques, and the token propagation method computes the necessary information only, on demand. Algorithms are presented for data flow and full slicing to calculate precise program slices. Preliminary application experiences on industrial‐scale COBOL systems are also summarized. Copyright

An agent based approach for migrating web services to semantic web services

Semantic web services are considered as the concept bringing the web to its full potential by combining the best features of web services, agent technology, grid and the semantic web. In this paper we present an agent based architecture for migrating existing web services to the semantic web service environment. We developed the WSDL2Agent tool to support the migration. The tool automatically generates a Protege project. With human interaction semantic information not present in the WSDL description can be added in Protege and the project can be exported in OWL format. From the enhanced OWL description we can directly derive the skeletons of the elements of the Web Services Modeling Framework. The tool automates the most tedious tasks of the migration process and the users can focus on the semantic aspects.

Knowledge Driven Architecture for Home Care

Multi-Agent Systems (MAS) in health-care domains are showing a rapid increase, in order to manage complex tasks and adapt gracefully to unexpected events. On the other hand, the lack of well-established agent-oriented engineering methodologies to transform knowledge level descriptions into deployable agent systems slackens MAS development. This paper presents a new methodology in modelling and automatically implementing agents in a home care domain. The representation of the application knowledge together with the codification of health care treatments lead to flexible realization of an agent platform that has the capability to capture new medical knowledge emerging from physicians.

Remote storage management in science gateways via data bridging

State‐of‐the‐art science gateways can be connected to several distributed computing infrastructures (DCIs) and are able to run jobs and workflows simultaneously in all those DCIs. Flexibility of accessing diverse data storages from these workflows and assisting end users to manage these storages are however the missing features in current gateway implementations, in which these problems often prove to be a barrier of exploiting the power of distributed computing by user communities having no or little IT competence. This paper addresses these issues by integrating a data bridging service called Data Avenue into WS‐PGRADE/gUSE portal framework. Data Avenue offers tools for the end users to easily manage their data residing on various storage resources, and also, jobs become capable of accessing different storages regardless of the particular distributed computing infrastructure where the job is currently being run. Copyright

Remote Storage Resource Management in WS-PGRADE/gUSE

State-of-the-art gateways are connected to several distributed computing infrastructures (DCIs) that are able to run jobs and workflows simultaneously in all those different DCIs. Data of e-Science applications might be stored on different storage resources, making it difficult for various user communities to browse, access, or update it. This chapter presents the Data Avenue concept and related tools that aim at hiding technical details of accessing different storage resources, and providing an easy-to-use file browsing interface to manage, upload and download, and even transfer data between different types of storage resources. Usage scenarios to exploit Data Avenue services as well as security considerations are discussed.

Data Avenue: Remote Storage Resource Management in WS-PGRADE/gUSE

State-of-the-art gateways are connected to several distributed computing infrastructures (DCIs) and are able to run jobs and workflows simultaneously in all those different DCIs. However, the flexibility of accessing data storages belonging to different DCIs is a missing feature of current gateways. SZTAKI (Institute for Computer Science and Control) has developed a Data Avenue Blacktop service and aLiferay-based Data Avenue port let that open the door for integrating such features into science gateways. The paper explains the design considerations of the Data Avenue Blacktop service and its usage scenarios in science gateways through the Data Avenue port let.

Spatial distribution of star formation related to ionized regions throughout the inner Galactic plane

We present a comprehensive statistical analysis of star-forming objects located in the vicinities of 1360 bubble structures throughout the Galactic plane and their local environments. The compilation of ~70 000 star-forming sources, found in the proximity of the ionized (Hii) regions and detected in both Hi-GAL and GLIMPSE surveys, provided a broad overview of the different evolutionary stages of star-formation in bubbles, from prestellar objects to more evolved young stellar objects (YSOs). Surface density maps of star-forming objects clearly reveal an evolutionary trend where more evolved star-forming objects (Class II YSO candidates) are found spatially located near the center, while younger star-forming objects are found at the edge of the bubbles. We derived dynamic ages for a subsample of 182 H ii regions for which kinematic distances and radio continuum flux measurements were available. We detect approximately 80% more star-forming sources per unit area in the direction of bubbles than in the surrounding fields. We estimate the clump formation efficiency (CFE) of Hi-GAL clumps in the direction of the shell of the bubbles to be ~15%, around twice the value of the CFE in fields that are not affected by feedback effects. We find that the higher values of CFE are mostly due to the higher CFE of protostellar clumps, in particular in younger bubbles, whose density of the bubble shells is higher. We argue that the formation rate from prestellar to protostellar phase is probably higher during the early stages of the (H ii) bubble expansion. Furthermore, we also find a higher fraction of massive YSOs (MYSOs) in bubbles at the early stages of expansion ( < 2 Myr) than older bubbles. Evaluation of the fragmentation time inside the shell of bubbles advocates the preexistence of clumps in the medium before the bubble expansion in order to explain the formation of MYSOs in the youngest H ii regions ( < 1 Myr), as supported by numerical simulations. Approximately 23% of the Hi-GAL clumps are found located in the direction of a bubble, with 15% for prestellar clumps and 41% for protostellar clumps. We argue that the high fraction of protostellar clumps may be due to the acceleration of the star-formation process cause by the feedback of the (Hii) bubbles.

Enabling Workflow-Oriented Science Gateways to Access Multi-Cloud Systems

In this paper we present a solution to cloud-enable workflow-oriented science gateways. The integration mechanism described in the paper is a generic method that can be followed by other gateway developers. The paper describes the principles and the concrete ways to integrate science gateways with multi-cloud systems. The concrete example to demonstrate the integration principles builds on the integration of WS-PGRADE/gUSE and the CloudBroker Platform (CBP). The integration of WS-PGRADE and the CloudBroker Platform offers a complete cloud-enabled science gateway platform for a diverse set of use-cases and user communities, with the availability to use mainstream cloud middleware types and services (Amazon, IBM, OpenStack, OpenNebula). The advantage of the integrated WS-PGRADE and CloubBroker Platform system is that if a domain-specific science gateway is customized from WS-PGRADE gateway framework it immediately inherits this cloud access flexibility, i.e. the user community of that gateway can access all the cloud types enabled by the integrated system presented.