Embedded systems such as Cyber-Physical Systems (CPS) are typically designed as a network of multiple interacting elements with physical input (or sensors) and output (or actuators). One aspect of interest of open systems is fidelity, or the compliance between physical figures of interest and their internal representation. High fidelity is defined as a stable mapping between actions in the physical domain and intended or expected values in the system domain and deviations from fidelity are quantifiable over time by some appropriate informative variable. In this paper, we provide a model for designing such systems based on a framework for trustworthiness monitoring and we provide a Jason implementation to evaluate the feasibility of our approach. In particular, we build a bridge between a standard publish/subscribe framework for CPS called MQTT and Jason to enable automatic reasoning about trustworthiness.

Are purely technological solutions the best answer we can get to the shortcomings our organizations are often experiencing today? The results we gathered in this work lead us to giving a negative answer to such question. Science and technology are powerful boosters, though when they are applied to the "local, static organization of an obsolete yesterday" they fail to translate in the solutions we need to our problems. Our stance here is that those boosters should be applied to novel, distributed, and dynamic models able to allow us to escape from the local minima our societies are currently locked in. One such model is simulated in this paper to demonstrate how it may be possible to tap into the vast basins of social energy of our human societies to realize ubiquitous computing sociotechnical services for the identification and timely response to falls.

The population of elderly people is increasing rapidly, which becomes a predominant aspect of our society. For several reasons so significant a share of the human society is simply regarded as "retired" -- a word condemning the elderly to a reduced participation in all active life, regardless of their actual conditions and abilities. In previous work, we discussed how community resources can be organized in a better way. In particular we introduced a so-called mutual assistance community -- a digital ecosystem that removes any predefined and artificial distinction between care-givers and care-takers and provides a service-oriented infrastructure for intelligent matching of the supply and demand of services. According to this new paradigm all people are potentially active participants to activities defined by the people's current needs, abilities, locations, and availabilities. Moving from this conceptual view to practical implementation calls for an architecture able to match adequately demand and supply of services. This paper presents an implementation of such an architecture based on semantic service description and matching. In comparison with our previous implementation, main added values include a greater flexibility in service representation and service matching and considerable improvements in performance.

SUMMARY As software systems today increasingly operate in changing and complex environments, they are expected to dynamically adapt to the changing environments sometimes with multiple coexisting adaptation goals. In this paper, an adaptation framework to facilitate adaptation with multiple concerns by using reusable and composable adaptation modules is proposed. Rather than using one‐size‐fits‐all approach, in this framework, system global adaptation behavior is generated by contextually fusing adaptation plans from multiple adaptation modules. In order to handle possible conflicts from multiple adaptation plans, supports for conflict detection and resolution are provided. Following the framework design principles, a supporting middleware is implemented based on the service‐oriented component model. Adaptation behaviors are realized as individually deployable adaptation components. A strategy called normalized context matching degree is proposed to rate and select applicable adaptation components. Possible conflicts in dealing with multiple adaptation concerns are resolved by using the semantics of actuators and context conditions. This middleware is also designed to be readily reconfigurable to support new features. Case studies and experiment results show that our framework exhibits significant advantage over traditional approaches in light of flexibility and reusability of the adaptation modules, with little complexity and performance overhead. Copyright © 2012 John Wiley & Sons, Ltd.

Merging the features of Cloud computing, autonomic computing, pervasive computing, and mobile computing are now at its initial stage but the effort is visibly showing the benefits of these paradigms. A large number of applications can take advantage of this, including healthcare, traffic control, and social network applications. However, these applications are complex by nature and introduce several challenges of their own, for example, reliable sensing, accurate context recognition, scalability, security, and the challenge of dealing with previously unforeseen side-effects of adaptations. These challenges can be surmounted when researchers of diverse background come together and provide different views of the same problems and help each other understand the complex relationships between contending ideas. The Casemans 2012 workshop opens the necessary platform for researchers of ubiquitous computing, autonomic computing, and similar fields to address these issues.

We present a family of gossiping algorithms whose members share the same structure though they vary their performance in function of a combinatorial parameter. We show that such parameter may be considered as a "knob" controlling the amount of communication parallelism characterizing the algorithms. After this we introduce procedures to operate the knob and choose parameters matching the amount of communication channels currently provided by the available communication system(s). In so doing we provide a robust mechanism to tune the production of requests for communication after the current operational conditions of the consumers of such requests. This can be used to achieve high performance and programmatic avoidance of undesirable events such as message collisions.

The vision of mobile and ubiquitous systems is becoming a reality thanks to the recent advances in wireless communication and device miniaturization. However, the widespread industrial uptake of these systems is still compromised by the highly error-prone and heterogeneous mobile provisioning environments, which induce several impairments to normal operation. Thus, how to improve the dependability of these systems is still an open issue.

This paper introduces a tool that allows designers to make use of adaptively redundant data structures with commodity programming languages such as C or Java. Designers using such tool can define redundant data structures in which the degree of redundancy is not fixed once and for all at design time, but rather it changes dynamically with respect to the disturbances experienced during the run time. Our approach attunes the degree of redundancy required to ensure data integrity to the actual faults being experienced by the system and provides an example of adaptive fault-tolerant software. We prove the effectiveness of our tool by showing that adaptive replication reaches the same effectiveness of static replication but consuming much less resources and computing time.

Elder people are becoming a predominant aspect of our societies. As such, solutions both efficacious and cost-effective need to be sought. This paper proposes a design to construct a virtual ambient assisted living community where dwellers make contributions to the community so as to best utilize resources and minimize costs. We use service oriented architecture (SOA) to orchestrate the available resources inside the community, thus bringing social intelligence to the social computing. We also propose building such a virtual community making use of virtual reality and in the form of serious game [Stuart Rory, 1996]. Daily activities and instruments (such as sensors, cameras, etc.) in real-life may be translated into their virtual community equivalents, and activities happening in the virtual world will trigger corresponding actions in the real world, so that inter-reality may be obtained through this virtual community. We expect such a virtual community could help not only efficiently utilizing the social resources in maintaining the independent living of the elderly people, but also helping these people maintain their connections to the society and bring them entertainment, so that the quality of their living standard may be improved at the same time.

Elder people are becoming a predominant aspect of our societies. As such, solutions both efficacious and cost-effective need to be sought. The approach pursued so far to solve this problem used to increase the number of people working in the health sector, e.g. doctors, nurses, etc. This increases the costs, which is becoming a big burden for countries. In this paper we propose a new concept in the health management of elder people, which we name as "participant". We propose the "participant" concept to encourage elder people to participate in those group activities that they are able to. Their roles in these activities are not passively requesting help, but actively participating to some healthcare processes. Characteristics of the participant approach are that medical resources are efficiently spared with this model, and the social network of the elder people is kept. A "virtual community" for mutual assistance is set up in this paper, and the simulations demonstrate that the "participant" model could fully utilize the community resources. Furthermore, the psychological health of the elder people will be improved.

Failure detection protocols an important building block of fault-tolerant distributed systems-are often described by their authors making use of informal pseudocodes of their own devising. Often these pseudo-codes use syntactical constructs that are not available in COTS programming languages such as C or C++. This translates into informal descriptions that require ad hoc interpretations and implementations. Being informal, these descriptions cannot be tested by their authors, which may translate into insufficiently detailed or even faulty specifications. Being non-standard, they require the reader to understand each time a different lingo. This paper tackles the above problem introducing a formal syntax for the expression of failure detection protocols and a C library that implements that syntax: a toolset to express and reason about failure detection protocols. The resulting specifications are more diffuse but non ambiguous and eligible for becoming a standard form among researchers and practitioners.

The so-called wireless revolution is producing new services based on the concept of mobile computing. We remark how mobile computing technologies call for effective software engineering techniques to design, develop and maintain mobile services, i.e., services that are prepared to continue the distribution of a fixed, agreed-upon quality of service despite of the changes in the location of the client software and the characteristics of the environment. Hence novel paradigms are required for software engineering so as to provide effective system structures for mobile services while keeping the design complexity under control. In this paper we discuss the problem and propose one such structure.

Elder people are becoming a predominant aspect of our societies and solutions both efficacious and cost-effective need to be sought. This paper proposes a service-oriented infrastructure approach to this problem. We propose an open and integrated service infrastructure to orchestrate the available resources (smart devices, professional carers, informal carers) to help elder or disabled people. Main characteristic of our design is the explicitly support of dynamically available service providers such as informal carers. By modeling the service description as Semantic Web Services, the service request can automatically be discovered, reasoned about and mapped onto the pool of heterogeneous service providers. We expect our approach to be able to efficiently utilize the available service resources, enrich the service options, and best match the requirements of the requesters.

A system structure for adaptive mobile applications is introduced and discussed, together with a compliant architecture, and a prototypic implementation. A methodology is also introduced, which exploits our structure to decompose the behavior of non-stable systems into a set of quasi-stable scenarios. Within each of these scenarios, we can exploit the knowledge of the available QoS figures to express simpler and better adaptation strategies.

Portable consumer devices are increasing their capabilities more and more and can now implement new multimedia algorithms that were reserved only for powerful workstations a few years ago. Unfortunately, the original design characteristics of such algorithms do not often allow them to be ported directly to current embedded devices. These algorithms share complex and intensive dynamic memory use and actual embedded systems cannot provide efficient general-purpose memory management as it is needed. As a result, dynamic memory optimizations are a requirement when porting these applications. Within these optimizations, the refinement of the dynamically (de)allocated abstract data type implementations in the complex multimedia applications involved is one of the most important and difficult parts for an efficient mapping of the algorithms on low-power and high-speed embedded consumer devices. We describe a high-level approach for modeling and refining complex data types using abstract derived classes in C++. This approach enables the multimedia developer to compose, evaluate and refine complex data types in a conceptually straightforward way, without a time-consuming programming effort

The DepAuDE architecture provides middleware to integrate fault tolerance support into distributed embedded automation applications. It allows error recovery to be expressed in terms of recovery strategies, i.e., lightweight code fragments separated from the application code. At run time, the middleware orchestrates their execution. This paper reports on the integration of different recovery scripts into a distributed run-time environment applied to the embedded automation system of a primary substation. An instrumented automata-based design environment allows the application to be deployed on a heterogeneous platform with several real-time operating systems. While the middleware detects the errors and selects the correct recovery scripts to be executed, the application functionality is maintained through system reconfiguration or graceful degradation. The added value comes from the flexibility to modify recovery strategies without requiring major modifications to the application, while tolerating the same physical faults as in the dedicated hardware solutions.

This paper describes a novel approach to software-implemented fault tolerance for distributed applications. This new approach can be used to enhance the flexibility and maintainability of the target applications in a cost-effective way. This is reached through a framework-approach including: (1) a library of fault tolerance functions; (2) a middleware application coordinating these functions; and (3) a language for the expression of nonfunctional services, including configuration, error recovery and fault injection. This framework-approach increases the availability and reliability of the application at a justifiable cost, also thanks to the re-usability of the components in different target systems. This framework-approach further increases the maintainability due to the separation of the functional behavior from the recovery strategies that are executed when an error is detected, because the modifications to functional and nonfunctional behavior are, to some extent, independent, and hence less complex to deal with. The resulting tool matches well, e.g., with current industrial requirements for embedded distributed systems, calling for adaptable and reusable software components. The "integration of this approach in an automation system of a substation for electricity distribution" reports this experience. This case study shows in particular the ability of the configuration-and-recovery language ARIEL to allow adaptability to changes in the environment. This framework-approach is also useful in the context of distributed automation systems that are interconnected via a nondedicated network.

Industrial embedded supercomputing applications benefit from a systematic approach to fault tolerance. The EFTOS (embedded fault-tolerant supercomputing) framework provides a flexible and adaptable set of fault-tolerance tools from which the application developer can choose to make an embedded application on a parallel or distributed system more dependable. A high-level description (recovery language) helps the developer specify the fault-tolerance strategies of the application as a second application layer; this separates functional from fault-tolerance aspects of an application, thus shortening the development cycle and improving maintainability. The framework incorporates a backbone (to hook a set of fault-tolerance tools onto, and to coordinate the fault-tolerance actions) and a presentation layer (to monitor and test the fault tolerance behavior). A practical implementation is described with its performance evaluation, using an industrial case study from the energy-transport area, as well as an analytic deduction of the appropriateness of fault-tolerance techniques for various application profiles.