Safety-Assured Model-Based Development of Real-Time Embedded Software for the Gpca Infusion Pump

Many safety-critical embedded systems must meet safety requirements associated with timing constraints. Not only shall a system read/write correct input or output values, but also those operations shall be performed with the right timing. Failing to meet those timing constraints results in serious safety issues (e.g., medical device malfunctions may harm patients). It is difficult to develop complex embedded software in a correct way without rigorous and systematic handling of various sources that affect the timed behavior of a system. We propose the model-based development framework that enables timing aspects of a system to be formally modeled, verified, and further implemented in a systematic way. The fundamental idea is to separate the timing concerns of the platform-independent and the platform-dependent aspects of a system. In the platform-independent development phase, input and output timed interactions between a system and its environment is modeled and verified using state-transition formalism (e.g., UPPAAL) by hiding platform-dependent timing details. In the platform-dependent development phase, such platform-dependent timing details are modeled using architectural modeling languages (e.g., AADL) that are necessary to execute the platform-independent code on a particular platform, such as internal interactions among software components (e.g., threads) and hardware components (e.g., sensors and actuators). The platform-independent code and the platform-dependent code are independently developed from the different levels of timing abstractions, and composed together in the integration phase. In this phase, we propose a way to systematically extend the platform-independent model into different platform-specific models, which formally characterize the implementation-level timed behavior that can be verified for timing requirement conformance. In case this verification step fails, we propose a way to adjust the timing parameters of the platform-independent code by compensating for the platform-dependent processing delays in such a way that the resulting implementation meets the timing requirements verified in the platform-independent model. Applicability of this development approach was demonstrated by developing software running on several Patient-Controlled Analgesia (PCA) infusion pump systems. We hope that this approach is also applicable to other safety-critical domains where generic software needs to be developed independently of a particular platform, and integrated with many different platforms in a way that conforms to timing requirements

Applying patterns in embedded systems design for managing quality attributes and their trade-offs

Embedded systems comprise one of the most important types of software-intensive systems, as they are pervasive and used in daily life more than any other type, e.g., in cars or in electrical appliances. When these systems operate under hard constraints, the violation of which can lead to catastrophic events, the system is classified as a critical embedded system (CES). The quality attributes related to these hard constraints are named critical quality attributes (CQAs). For example, the performance of the software for cruise-control or self-driving in a car are critical as they can potentially relate to harming human lives. Despite the growing body of knowledge on engineering CESs, there is still a lack of approaches that can support its design, while managing CQAs and their trade-offs with noncritical ones (e.g., maintainability and reusability). To address this gap, the state-of-research and practice on designing CES and managing quality trade-offs were explored, approaches to improve its design identified, and the merit of these approaches empirically investigated. When designing software, one common approach is to organize its components according to well-known structures, named design patterns. However, these patterns may be avoided in some classes of systems such as CES, as they are sometimes associated with the detriment of CQAs. In short, the findings reported in the thesis suggest that, when applicable, design patterns can promote CQAs while supporting the management of trade-offs. The thesis also reports on a phenomena, namely pattern grime, and factors that can influence the extent of the observed benefits

Cognitive aspects of work with digital maps

Digital maps of geographic areas are increasingly common in many types of workplace, in education and in the public domain. Their interactivity and visual features, and the complexity of geographic(al) information systems (GIS) which create, edit and manipulate them, create special cognitive demands on the end-user which are not present in traditional cartographic maps or in most human-computer interaction (HCI). This thesis reviews cross-disciplinary literature regarding cognitive aspects of viewing and interacting with digital maps. Data from an observational study of GIS use, including real-time recordings of normal workplace activities, was analysed using various approaches to examine the interactive and visual aspects of people's work. The implications for cartographic, psychological and HeI aspects of GIS are discussed, in the context of the actual tasks people perform with them (rather than the computationally advanced analyses assumed by most literature). The second phase of the research examined the spatial knowledge attained and used during this interaction. The relevance of specific concepts in cognitive psychology, and of factors that create individual differences in cognition, are discussed in depth, alongside work in environmental and educational psychology, cartography and geography. A controlled experiment examined the degree to which task characteristics induce a different spatial model or reference frame when viewing a digital map. It was shown that even novice users can switch between considering the map as an abstract geometric display or as a geographical representation, without affecting performance. However, tasks forcing subjects to focus entirely on the geometry rather than the geography did affect performance in a surprise post-test photograph identification task. Map users' mental model or reference frame is apparently affected by these task constraints; this has implications for GIS design and practice as well as for understanding spatial cognition The study also considered the role of expertise and other individual difference factors, although conclusions were limited by sample size. Further research issues are highlighted, particularly regarding the knowledge structures and spatial language used in interpreting digital maps

Proceedings of the 19th Sound and Music Computing Conference

Proceedings of the 19th Sound and Music Computing Conference - June 5-12, 2022 - Saint-Étienne (France). https://smc22.grame.f

The Music Sound

A guide for music: compositions, events, forms, genres, groups, history, industry, instruments, language, live music, musicians, songs, musicology, techniques, terminology , theory, music video. Music is a human activity which involves structured and audible sounds, which is used for artistic or aesthetic, entertainment, or ceremonial purposes. The traditional or classical European aspects of music often listed are those elements given primacy in European-influenced classical music: melody, harmony, rhythm, tone color/timbre, and form. A more comprehensive list is given by stating the aspects of sound: pitch, timbre, loudness, and duration. Common terms used to discuss particular pieces include melody, which is a succession of notes heard as some sort of unit; chord, which is a simultaneity of notes heard as some sort of unit; chord progression, which is a succession of chords (simultaneity succession); harmony, which is the relationship between two or more pitches; counterpoint, which is the simultaneity and organization of different melodies; and rhythm, which is the organization of the durational aspects of music