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For the integration of a reactive multilayer system (iRMS) with a high exothermic reaction enthalpy as a heat source on silicon wafers for low-temperature bonding in the 3D integration and packaging of microsystems, two main conflicting issues should be overcome: heat accumulation arising from the layer interface pre-intermixing, which causes spontaneous self-ignition during the deposition of the system layers, and conductive heat loss through the substrate, which leads to reaction propagation quenching. In this work, using electron beam evaporation, we investigated the growth of a high exothermic metallic Pd/Al reactive multilayer system (RMS) on different Si-wafer substrates with different thermal conduction, specifically a bare Si-wafer, a RuOx or PdOx layer buffering Si-wafer, and a SiO2-coated Si-wafer. With the exception of the bare silicon wafer, the RMS grown on all other coated wafers underwent systematic spontaneous self-ignition surging during the deposition process once it reached a thickness of around 1 μm. This issue was surmounted by investigating a solution based on tuning the output energy by stacking alternating sections of metallic reactive multilayer Pd/Al and Ni/Al systems that have a high and medium enthalpy of exothermic reactions, respectively. This heterostructure with a bilayer thickness of 100 nm was successfully grown on a SiO2-coated Si-wafer to a total thickness of 3 μm without any spontaneous upsurge of self-ignition; it could be electrically ignited at room temperature, enabling a self-sustained propagating exothermic reaction along the reactive patterned track without undergoing quenching. The results of this study will promote the growth of reactive multilayer systems by electron beam evaporation processing and their potential integration as local heat sources on Si-wafer substrates for bonding applications in microelectronics and microsystems technology.

A novel approach to the remote‐control system for the compact multi‐crystal energy‐dispersive spectrometer for X‐ray emission spectroscopy (XES) applications has been developed. This new approach is based on asynchronous communication between software components and on reactive design principles. In this paper, the challenges faced, their solutions, as well as the implementation and future development prospects are identified. The main motivation of this work was the development of a new holistic communication protocol that can be implemented to control various hardware components allowing both independent operation and easy integration into different SCADA systems. A novel approach to the remote‐control system for the compact multi‐crystal energy‐dispersive spectrometer for X‐ray emission spectroscopy applications is described.

In telecommunications and software engineering, testing is normally understood to be essentially active: a tester is said to stimulate, control, and enforce. Passive testing does not fit this paradigm and thus remains the niche research subject, which bears on the scope and depth of the obtained results. It is argued that such limited understanding of testing is one of its many community-bound preconceptions. It may be acceptable in the current engineering approach to testing, but can and should be challenged in order to converge on the core concepts of the proposed science of testing (“testology”). This methodological work aims at establishing that there are no fundamental reasons for admitting the dominant role of the active element in testing. To show this, external (also extratechnical) areas are consulted for insight, direct observations, and metaphors. The troublesome distinction between (passive) testing and monitoring, as well as unclear relations between testing and measurements, are also addressed.

Time Petri nets describe the state of a timed system through a marking and a set of clocks. If clocks take values in a dense domain, state space analysis must rely on equivalence classes. These support verification of logical sequencing and quantitative timing of events, but they are hard to be enriched with a stochastic characterization of nondeterminism necessary for performance and dependability evaluation. Casting clocks into a discrete domain overcomes the limitation, but raises a number of problems deriving from the intertwined effects of concurrency and timing. We present a discrete-time variant of time Petri nets, called stochastic preemptive time Petri nets, which provides a unified solution for the above problems through the adoption of a maximal step semantics in which the logical location evolves through the concurrent firing of transition sets. We propose an analysis technique, which integrates the enumeration of a succession relation among sets of timed states with the calculus of their probability distribution. This enables a joint approach to the evaluation of performance and dependability indexes as well as to the verification of sequencing and timeliness correctness. Expressive and analysis capabilities of the model are demonstrated with reference to a real-time digital control system.

In this paper, we propose a generalization for fuzzy graphs in order to model reactive systems with fuzziness. As we will show, the resulting fuzzy structure, called fuzzy reactive graphs (FRG), is able to model dynamical aspects of some entities which generally appear in: biology, computer science and some other fields. The dynamical aspect is captured by a transition function which updates the values of the graph after an edge has been crossed. The update process takes into account aggregation functions. The paper proposes a notion for bisimulation for such graphs and briefly shows how modal logic can be used to verify properties of systems modeled with FSGs. The paper closes with a toy example in the field of Biology.

Changes are inevitable in software due to technology advancements, and changes in business requirements. Making changes in the software by insertion, deletion or modification of new code may lead to malfunctioning of the old code. Hence, there is a need for a priori analysis to ensure and capture these types of changes to run the software smoothly. Making changes in the software while it is in use is called dynamic evolution. Due to the lack of formal modeling and verification, this dynamic evolution process of software systems has not become prominent. Hence, we used the bigraphical reactive system (BRS) technique to ensure that changes do not break the software functionality (adversely affect the system). BRS provides a powerful framework for modeling, analyzing, and verifying the dynamic evolution of software systems, resulting in ensuring the reliability and correctness of evolving software system. In this paper, we proposed a formal method technique for modeling and verifying the dynamic evolution process (changing user requirements at run time) using the BRS. We used a bigraph to model software architectures and described the evolution rules for supporting the dynamic changes of the software system. Finally, we have used the BigMC model checker tool to validate this model with its properties and provide associated verification procedures.

A fundamental challenge in the synthesis of reactive systems is the size of the search space: the number of candidate implementations of a temporal specification is typically superexponential or even, for distributed system architectures, infinite. In this article, we introduce the bounded synthesis approach, which makes it possible to traverse this immense search space in a structured manner. We fix a bound on a system parameter, such as the number of states, and limit the search to those implementations that fall below the bound. By incrementally expanding the search to larger bounds, we maintain completeness, while orienting the search towards the simplest (and often most useful) solutions. The technical backbone of this solution is a novel translation from formulas of linear-time temporal logic to sequences of safety tree automata, which are guaranteed to underapproximate the specification and to eventually become emptiness-equivalent. Bounded synthesis is applicable to the entire range of synthesis problems, from individual processes to synchronous and asynchronous distributed systems, to systems with additional design constraints, such as symmetry. We include experimental results from a SMT-based implementation, which demonstrate that bounded synthesis solves many synthesis problems that were previously considered intractable.

In this paper, we propose a new approach, based on bigraphic reactive systems (BRS), to provide a formal modelling of the architectural elements of a Multi-Viewpoints ontology (MVp ontology). We introduce a formal model in which the main elements of MVp ontology find their definition in terms of bigraphic concepts by preserving their semantics. Besides, we enrich the proposed model with reaction rules in order to handle the dynamic reactions of MVp ontology. In order to confirm the applicability of our approach, we have carried out a case study using the proposed model.

Although simple wireless communication involving nodes built of microcontrollers and radio devices from the low end of the price spectrum is quite popular these days, one seldom hears about serious wireless networks built from such devices. Most of the commercially available nodes for ad hoc networking (somewhat inappropriately called \"motes\") are in fact quite serious computers with megabytes of RAM and rather extravagant resource demands. We show how one can build practical ad hoc networks using the smallest and cheapest devices vailable today. In our networks, such devices are capable of sustaining swarm-intelligent sophisticated routing while offering enough processing power to cater to complex applications involving distributed sensing and monitoring.

PurposeAn understanding of the role of decision-making has been emphasised since the seminal works on human information processing and professional judgements by accountants. The interest in these topics has been reignited by the increasing digitisation of the financial reporting and auditing processes. Whilst the behavioural research on accounting is well-established, the application of seminal works in cognitive psychology and behavioural finance is lacking, especially from recent research endeavours. The purpose of this paper is to provide a synthesis of theories relating to accounting behavioural research by evaluating them against the theories of cognitive psychology.Design/methodology/approachUsing theory synthesis, this research draws seemingly isolated strands of research into a coherent framework, underpinned by cognitive psychology.FindingsEvidence from accounting and auditing behavioural research is largely consistent with the psychology and finance research on cognitive limitations and errors. There remains a lacuna in accounting behavioural research on debiasing techniques. Such research, if underpinned by a single, cohesive theoretical framework, is likely to have practical relevance.Research limitations/implicationsThe current research has theoretical implications for the accounting decision-making and uncertainty research. Areas for future research, based on identified gaps in the current accounting behavioural research, are also proposed.