Blockchain technologies have emerged to serve as a trust basis for the monitoring and execution of business processes, particularly business process choreographies. However, dealing with changes in smart contract-enabled business processes remains an open issue. For any required modification to an existing smart contract (SC), a new version of the SC with a new address is deployed on the blockchain and stored in a contract registry. Moreover, in a choreography, a change in a partner process might affect the processes of other partners, and thus, must be propagated to partners affected by the change. In this paper, we propose an approach overcoming the limitations of SCs and allowing for the change management of blockchain-enabled declarative business process choreographies modeled as DCR graphs. Our approach allows a partner in a running blockchain-based DCR choreography instance to change its private process. A change impacting other partners is propagated to their processes in a decentralized manner using a SC. The change propagation mechanism ensures the compatibility checks between public processes of the partners and the consistency between the private and public processes of one partner. We demonstrate the approach’s feasibility through an implemented prototype and its effectiveness via a set of evaluation tests.

COVID-19 raised our dependency on computers and mobile devices to perform daily tasks. Thus, we saw a user face the challenges of managing multiple services/device environments. Therefore, this multiple services/devices scenario becomes significant while we still face the lack of interoperability between operating systems, services, and applications on devices. Additionally, big tech companies are fighting to pursue new web technologies for their services. Additionally, they require more resources from devices to keep running. Beyond that, we had to learn and adapt to a new set of server-side services for web meetings, such as Microsoft Teams, Zoom, Google Meet, and Webex. However, we did not see any propositions on the user side for the same web services that could continuously and undisruptive provides a similar user experience of web-service migration in a multiple-devices scenario regardless of the operating system. Therefore, this paper focuses on web services based on REST, RESTful, or GraphQL to analyze their performance using the System Usability Scale. Additionally, we focus on a real-life experiment on multiple-device environments for synchronizing web services’ user instances without continuously depending on a cloud-based system. We presented results from 35 users, where we measured various metrics over the previously mentioned web services through three different devices. Moreover, we revisited The CUBE architecture, enhancing features that allow us to obtain new results. The results demonstrate that when the users used the CUBE, they had a better QoS experience, low latency, and better response time. Moreover, the CUBE provides computational performance up to ≈69% faster than the traditional cloud-based synchronization procedure.

Abstract Nowadays, we live in an interconnected ecosystem of heterogeneous services which are available anytime and anywhere. Although these services can be used individually, their combined usage provides end‐users with real added value. Nevertheless, existing mashup solutions are not fully targeted to end‐users. Indeed, these solutions require technical knowledge to deal with the technological heterogeneity in which they are offered. The key limitation of current mashup solutions is their general‐purpose nature, which privileges expressive power over intuitiveness. As the reason for mashups was the desire of end‐users to build applications responding to their situational needs, we propose a domain‐specific mashup approach that “speaks the language of the user.” The article presents (1) a domain‐specific visual language that allows end‐users to easily build mashup‐based compositions, (2) a mashup schema which is a gateway between service implementations and end‐users, providing a high‐level description in order to hide technological issues when including services in composition; and (3) a configuration module that executes the travel mashup query and generates a personalized trip planning. The results of a user study confirm that domain‐specific mashup tools lower the entry barrier to mashup development.

Collaborative Internet of Things (C-IoT) is an emerging paradigm that has generated a large amount of accessible and usable data in real-time, constituting an interesting tool for decision-making problems. The paper presents a healthcare data analytics approach based on collecting and analyzing data from C-IoT. We first provide an architectural plan involving several distributed sites collaborating to collect necessary data for patient's health conditions monitoring. We use for that well-known IoT technologies like Radio Frequency IDentification (RFID), Near Field Communication(NFC), Beacons and Ambient Assisted Living sensors. We then learn on such data to create adequate patient profiles and use the Pearson Correlation Coefficient (PCC) over a long period of time data to detect potential health risks. Finally, decisions are made regarding the patient's condition according to the symptoms/diseases detected.

Over the last few years, multiple-device ownership have continuously and rapidly increased, driven by the continuous progress of Internet of Things solutions deployment. At the same time, the way people use their multiple devices is also changing making it common and even necessary to switch from one device to another for the same task. This evolution raises several issues regarding the migration process and the choice of the device to migrate to. In this paper, we address the problem of recommending the most suitable devices for a successful migration. We propose a semantic and rule-based approach for device recommendation that takes into account the characteristics of devices, services, and migration contexts. We propose an OWL ontology defining the necessary concepts describing devices, services, users, etc. and the relationships between them. Based on this ontology, we propose a set of SWRL rules defining the common requirements for a successful service migration across devices. The ontology is populated in real-time using appropriate APIs to get devices and context characteristics. This allows the rule-based reasoning to be held over updated values and provides relevant recommendations. The approach is implemented as a recommendation system within a web application to demonstrate its effectiveness and scalability.

Smart Contracts (SC for short) are gaining momentum as a suitable technology for ensuring trusted execution of Business Processes (BP for short) in open environment. Nevertheless, the transactional semantics of SC which follow ACID transactions are not appropriate for BP characteristics. Indeed, it is admitted that ACID transactions are limited to cope with complex control structure and long running execution of BP. Transactional Business Processes (TBP for short) have emerged as an extension to ACID models to overcome these limits. A TBP ensures transactional reliability of advanced transactions having a control structure as complex as for BP. In this paper, we propose an approach that builds on SC and extends them to implement TBP. We extend Caterpillar, an existing BP execution engine developed on top of Ethereum, to implement our approach and support the execution of TBP.

Blockchain trends cover more and more tech domains making it one of the most used technologies in the last few years. This is due to two essential aspects. First, it is a distributed peer-to-peer network where there is no need for third part to execute operations between peers. Second, blockchain implements mechanisms to make the most data sensitive operations executed in a trusted way. Regarding these attractive aspects, we intend in this work to use the blockchain technology for the implementation of touristic itineraries. We consider the latter as process choreographies involving different participants. We intend to model and execute the touristic itineraries generated from a personalized trip planner called CART in raw XML format in a way that respects this collaborative aspect and resolves the problem of trust. We will propose a pattern and its transformation rules to reconstruct the itineraries presented in declarative annotations such as XML to smart contracts written in some smart contract-specific programming language called Solidity. Experimental results show promising perspectives of the deployment of the proposed solution to execute touristic plans.

A huge amount of Tourism information is provided through myriad Web services. Travelers who want to plan their trips have to sift through a large pool of Web services before figuring out the best itinerary of places to visit. Such a process gets even more tedious when travelers need to satisfy specific constraints such as visit time and price. In this paper, we propose a linked open data (LOD) service recommendation approach to help travelers plan their trips (i.e., a sequence of places to visit) given a set of preferences and constraints. The proposed approach runs a three-step process. The first step consists of annotating a set of touristic Web services with LOD resources that describe their capabilities. The second step matches user constraints and preferences with Web service provided touristic information and returns a pre-list of itineraries. The third step runs a LOD-based matching between services to improve trips recommendation. Experiments conducted on real data show promising results.

Nowadays we live with a large number of different connected devices with various operating systems. This is leading us to a lack of technological solutions to deal with this multiple connected devices owned by the same user. Thus, a new way to create applications is required in order to enhance the user experience regardless the operating systems of devices. In this work, we present a client mail, based on CUBE model principals, allowing the user changing device while using a mail service without losing session/data or connection. Preliminary results demonstrate its feasibility to move from a Windows system to an Android one while keeping the mail service running.

Configuration theory has shown its usefulness for capturing the user's constraints and to assist her in mass customized composite components development. We bring in this paper configuration to the Web services context and provide personalized features for composite services. The process of configuring a composite Web service results on a planning-style approach that creates new Web services through combining existing ones while considering user's constraints and preferences. We propose a bottom-up reasoning approach that connects services based on configuration knowledge witch includes configuration operators and configuration rules in order to generate the configured service that cover the tourist's information need. A positive yet preliminary evaluation with tourists has been carried out and shows the usability of our approach.

The fast development of powerful mobile devices and rich Internet applications have boosted the production of Mobile Web applications designed to support end-users in their daily activities using smartphones. When these applications are the result of combining multiple heterogeneous data and services, the traditional one-size-fits-all development approach is not convenient since it does not consider the specificities of each potential user. New techniques and tools are then required to offer applications that better fit end-users constraints, preferences, and contexts while allowing them creating, consuming and sharing added-value services. We present in this article a novel mashup approach based on configuration theory and a visual tool that achieves this goal. As a proof of concept, we present an implementation scenario in the tourism domain.

International audience

A large set of Web services are nowadays available providing complementary content about: schedule of public transportation, description of touristic area, eteorological information, geocoding operations, etc. We present in this article a mobile-application prototype that mashups Web services to define custom touristic plans, i.e., takes into account tourist preferences (type of stay, interest) and constraints (duration, budget, locomotion modality). Moreover, the application considers real-time events (e.g., weather data or temporary unavailability of a touristic site) to adapt proposed schedules.

With the rapid evolution of Linked Open Data (LOD), researchers are exploiting it to solve particular problems such as semantic similarity assessment. Existing LOD-based semantic similarity approaches attach compared data (terms or concepts) to LOD resources to exploit their semantic descriptions and relationships with other resources and estimate the degree of overlap between resources. Current approaches suffer from two limitations: they focus on the analysis of links between resources and ignore the important taxonomic structure of concepts and categories used to describe resources. On the other hand, they do not exploit interlinks between LOD resources in order to enrich data used to compute the similarity score. In this paper, we overcome the above limitations by proposing a new LOD-based similarity measure based on the combination of ontological, classification and property dimensions of LOD resources.

Classifying Web services into functionally similar groups is an efficient way to enhance services discovery, composition, and substitution processes. In order to ensure such efficiency, the classification process should rely on adequate semantic similarity measures. This paper presents a practical approach to measure the similarity of Web services. Both semantic and syntactic descriptions are integrated through specific techniques for computing similarity measures between services. Formal Concept Analysis (FCA) is used then to classify Web services into concept lattices in order to facilitate relevant services identification for composition and/or substitution purposes. The proposed similarity measure is evaluated and compared to some of the best-known existing ones. Results show a significant improvement of precision and recall of relevant services discovery for further composition and substitution tasks.

To exploit the true potential of Web services, it is critical to develop technologies and tools for composing new services from existing ones. Indeed, to reduce development time and integration efforts, this process of service composition requires an effective development environment to facilitate quick and simple composition of Web services, and remains a key challenge to realize the true potential of Web services. While numerous composition approaches have been developed, very little has been done towards providing an Integrated Development Environment to ease the process of composition. In this context, this paper introduces a new incremental approach to service composition engineering and considers the composition global life-cycle, i.e. specifying, composing, verifying, deploying, monitoring, and analyzing to achieve a full governance of the composition.

In this paper we propose an approach which combines semantic resources and formal concept analysis to deal with heterogenous data sets represented as many-valued (MV) formal contexts. We define a new Galois connection considering the semantic relationships between attribute values in a MV context. The semantic relationships are used to calculate the similarity between attribute values to decide whether an attribute is shared by a set of objects or not. Then, based on this Galois connection, we define MV formal concepts and MV concept lattices. Depending on a chosen similarity threshold, MV concept lattices may have different levels of precision. We take advantage of this feature to browse the content of a biological databases repository in a dynamic and progressive way. The browsing process combines the navigation in several MV concept lattices and allows zooming operations by switching between MV concept lattices with higher or lower precision.

In this paper we present an extension of the Galois connection to deal with many-valued formal contexts. We define a many-valued Galois connection with respect to similarity between attribute values in a many-valued context. Then, we define many-valued formal concepts and many-valued concept lattices. Depending on a similarity threshold, many-valued concept lattices may have different levels of precision. This feature makes them very useful for multilevel conceptual clustering. Many-valued concept lattices are also used in a new lattice-based information retrieval approach for efficiently answering complex queries.

Biological databases are blooming today at an increasing rate to deal with the huge amount of data produced by genomic and post-genomic research. The need for a well-maintained searchable directory is therefore an important issue for a good exploitation of these databases. The BioRegistry repository is automatically generated from a publicly available list of biological databases (The Molecular Biology Database Collection published in Nucleic Acids Research) and aims at associating content metadata with each database in view of database retrieval and/or discovery. Such content metadata are either simple keywords or terms belonging to a medical thesaurus. Querying modalities including a search by semantic similarity are described. The use of conceptual clustering methods is proposed to build a semantic classification of biological databases enabling browsing through the BioRegistry repository and discovering previously unknown databases.