arXiv subjects

Vincenzo De Florio

Publications and source records attributed to Vincenzo De Florio.

45 records · Page 3Linked to original sources

arXiv2014

Reflective and Refractive Variables: A Model for Effective and Maintainable Adaptive-and-Dependable Software

We propose a simple and effective tool for the expression of tasks such as cross-layer optimization strategies or sensors-related applications. The approach is based on what we refer to as "reflective and refractive variables". Both types of variables are associated with external entities, e.g. sensors or actuators. A reflective variable is a volatile variable, that is, a variable that might be concurrently modified by multiple threads. A library of threads is made available, each of which interfaces a set of sensors and continuously update the value of a corresponding set of sensors. One such thread is "cpu", which exports the current level of usage of the local CPU as an integer between 0 and 100. This integer is reflected into the integer reflective variable cpu. A refractive variable is a reflective variable that can be modified. Each modification is caught and interpreted as a request to change the value of an actuator. For instance, setting variable "tcp_sendrate" would request a cross-layer adjustment to the thread interfacing the local TCP layer entity. This allows express in an easy way complex operations in the application layer of any programming language, e.g. plain old C. We describe our translator and the work we are carrying out within PATS to build simple and powerful libraries of scripts based on reflective and refractive variables, including robotics applications and RFID tags processing.

cs.SE↗

arXiv2014

Service-oriented Communities: Visions and Contributions towards Social Organizations

With the increase of the populations, resources are becoming scarcer, and a smarter way to make use of them becomes a vital necessity of our societies. On the other hand, resource management is traditionally carried out through well established organizations, policies, and regulations that are often considered as impossible to restructure. Our position is that merely expanding the traditional approaches might not be enough. Systems must be radically rethought in order to achieve a truly effective and rational use of the available resources. Classical concepts such as demand and supply need to be rethought as well, as they operate artificial classifications that limit the true potential of systems and organizations. In what follows we propose our vision to future, "smarter" systems able to overcome the limitations of the status quo. Such systems require what Boulding called "gestalts," namely concepts able to "directing research towards the gaps which they reveal". In this paper we elaborate on this and show how such gestalts can pave the way towards novel reformulations of traditional services able to reach a better and more sensible management of the available resources and cope with their scarcity. Our vision of a Service-oriented Community is also introduced. We believe that such communities---in heterarchical coexistence with traditional systems---provide the necessary diversity and innovation orientation to prevent societal lock-ins such as the ones we are experiencing in assisting our elderly ones.

cs.CY↗

arXiv2014

A Service-oriented Infrastructure Approach for Mutual Assistance Communities

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 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.

cs.CY↗

arXiv2014

$\mathcal R\!\raise2pt\hbox{$\varepsilon$}\!\hbox{$\mathcal L$}$: A Fault Tolerance Linguistic Structure for Distributed Applications

The embedding of fault tolerance provisions into the application layer of a programming language is a non-trivial task that has not found a satisfactory solution yet. Such a solution is very important, and the lack of a simple, coherent and effective structuring technique for fault tolerance has been termed by researchers in this field as the "software bottleneck of system development". The aim of this paper is to report on the current status of a novel fault tolerance linguistic structure for distributed applications characterized by soft real-time requirements. A compliant prototype architecture is also described. The key aspect of this structure is that it allows to decompose the target fault-tolerant application into three distinct components, respectively responsible for (1) the functional service, (2) the management of the fault tolerance provisions, and (3) the adaptation to the current environmental conditions. The paper also briefly mentions a few case studies and preliminary results obtained exercising the prototype.

cs.DC↗

arXiv2014

The EFTOS Voting Farm: A Software Tool for Fault Masking in Message Passing Parallel Environments

We present a set of C functions implementing a distributed software voting mechanism for EPX or similar message passing environments, and we place it within the EFTOS framework (Embedded Fault-Tolerant Supercomputing, ESPRIT-IV Project 21012) of software tools for enhancing the dependability of a user application. The described mechanism can be used for instance to implement restoring organs i.e., N-modular redundancy systems with N-replicated voters. We show that, besides structural design goals like fault transparency, this tool achieves replication transparency, a high degree of flexibility and ease-of-use, and good performance.

cs.DC↗

arXiv2014

A Hypermedia Distributed Application for Monitoring and Fault-Injection in Embedded Fault-tolerant Parallel Programs

We describe a distributed, multimedia application which is being developed in the framework of the ESPRIT-IV Project 21012 EFTOS (Embedded Fault-Tolerant Supercomputing). The application dynamically sets up a hierarchy of HTML pages reflecting the current status of an EFTOS-compliant dependable application running on a Parsytec CC system. These pages are fed to a World-Wide Web browser playing the role of a hypermedia monitor. The adopted approach allows the user to concentrate on the high-level aspects of his/her application so to quickly assess the quality of its current fault-tolerance design. This view of the system lends itself well for being coupled with a tool to interactively inject software faults in the user application; this tool is currently under development.

cs.DC↗

arXiv2014

Software Tool Combining Fault Masking with User-Defined Recovery Strategies

We describe the voting farm, a tool which implements a distributed software voting mechanism for a number of parallel message passing systems. The tool, developed in the framework of EFTOS (Embedded Fault-Tolerant Supercomputing), can be used in stand-alone mode or in conjunction with other EFTOS fault tolerance tools. In the former case, we describe how the mechanism can be exploited, e.g., to implement restoring organs ($N\!$-modular redundancy systems with $N\!$-replicated voters); in the latter case, we show how it is possible for the user to implement in an easy and effective way a number of different recovery strategies via a custom, high-level language. Combining such strategies with the basic fault masking capabilities of the voting tool makes it possible to set up complex fault-tolerant systems such as, for instance, $N$-and-$M$-spare systems or gracefully degrading voting farms. We also report about the impact that our tool can have on reliability, and we show how, besides structural design goals like fault transparency, our tool achieves replication transparency, a high degree of flexibility and ease-of-use, and good performance.

cs.DC↗

arXiv2014

Participant: A New Concept for Optimally Assisting the Elder People

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.

cs.CY↗

arXiv2014

The Missing Ones: Key Ingredients Towards Effective Ambient Assisted Living Systems

The population of elderly people keeps increasing rapidly, which becomes a predominant aspect of our societies. As such, solutions both efficacious and cost-effective need to be sought. Ambient Assisted Living (AAL) is a new approach which promises to address the needs from elderly people. In this paper, we claim that human participation is a key ingredient towards effective AAL systems, which not only saves social resources, but also has positive relapses on the psychological health of the elderly people. Challenges in increasing the human participation in ambient assisted living are discussed in this paper and solutions to meet those challenges are also proposed. We use our proposed mutual assistance community, which is built with service oriented approach, as an example to demonstrate how to integrate human tasks in AAL systems. Our preliminary simulation results are presented, which support the effectiveness of human participation.

cs.CY↗