A tool for monitoring and maintaining system trustworthiness at runtime

Trustworthiness of software systems is a key factor in their acceptance and effectiveness. This is especially the case for cyber-physical systems, where incorrect or even sub-optimal functioning of the system may have detrimental effects. In addition to designing systems with trustworthiness in mind, monitoring and maintaining trustworthiness at runtime is critical to identify issues that could negatively affect a system's trustworthiness. In this paper, we present a fully operational tool for system trustworthiness maintenance, covering a comprehensive set of quality attributes. It automatically detects, and in some cases mitigates, trustworthiness threatening events. The use of such a tool can enable complex software systems to support runtime adaptation and self-healing, thus reducing the overall upkeep cost and complexity

Cyber-physical systems design for runtime trustworthiness maintenance supported by tools

The trustworthiness of cyber-physical systems is a critical factor for establishing wide-spread adoption of these systems. Hence, especially the behavior of safety-critical software components needs to be monitored and managed during system operation. Runtime trustworthiness maintenance should be planned and prepared in early requirements and design phases. This involves the identification of threats that may occur and affect user’s trust at runtime, as well as related controls that can be executed to mitigate the threats. Furthermore, observable and measureable system quality properties have to be identified as indicators of threats, and interfaces for reporting these properties as well as for executing controls have to be designed and implemented. This paper presents a process model for preparing and designing systems for runtime trustworthiness maintenance, which is supported by several tools that facilitate the tasks to be performed by requirements engineers and system designer

Naphthalene-based periodic nanoporous organosilicas: I. Synthesis and structural characterization

Novel periodic nanoporous organosilicas (PNOs) were synthesized by direct co-condensation of tetraethylorthosilicate and of the prior synthesized compound triethoxy(naphthalen-1-yl)silane. Structural characterization of materials was performed with various techniques such as 1H and 13C nuclear magnetic resonance, X-ray powder diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible and photoluminescence emission and excitation spectroscopy, differential thermal and thermo-gravimetric analyses, nitrogen porosimetry and helium pycnometry. Naphthalene-based moieties were grafted on the silicate matrix through oxygen bonds resulted to novel organosilicate final materials that exhibited high naphthalene content up to 17 wt.% with a corresponding 1.33 mmol/g molar concentration, high crystallinity, specific surface area larger than 1000 m 2/g and pore size distributions in the microporous/mesoporous boundary. Optical properties have been found to be comparable to the naphthalene. The attachment of the optically active part to the mesopores walls and its specific tuning for blue/UV luminescence demonstrates that this type of the reported low cost materials can be considered as phosphors in UV Leds. Tuning by using the red shift of similar larger molecules, all simultaneously trapped within the PNO, may prove to be efficient white light phosphor. Moreover, the nonlinear active properties of the active naphthalene may also allow for novel applications. Finally, materials were studied for hydrogen and methane storage with Sieverts' apparatus and demonstrated high H 2 and CH 4 weight proportions for PNOs materials at various temperatures up to 4.3 MPa and 3.5 MPa respectively as presented in part II. © 2012 Elsevier Inc. All rights reserved