The growing need to test systems post-release has led to extending testing activities into production environments, where uncertainty and dynamic conditions pose significant challenges. Field testing approaches, especially Self-Adaptive Testing in the Field (SATF), face hurdles like managing unpredictability, minimizing system overhead, and reducing human intervention, among others. Despite its importance, SATF remains underexplored in the literature. This work introduces AdapTA (Adaptive Testing Approach), a novel SATF strategy tailored for testing Body Sensor Networks (BSNs). BSNs are networks of wearable or implantable sensors designed to monitor physiological and environmental data. AdapTA employs an ex-vivo approach, using real-world data collected from the field to simulate patient behavior in in-house experiments. Field data are used to derive Discrete-Time Markov Chain (DTMC) models, which simulate patient profiles and generate test input data for the BSN. The BSN’s outputs are compared against a proposed oracle to evaluate test outcomes. AdapTA’s adaptive logic continuously monitors the system under test and the simulated patient, triggering adaptations as needed. Results demonstrate that AdapTA achieves greater effectiveness compared to a non-adaptive version of the proposed approach across three adaptation scenarios, emphasizing the value of its adaptive logic.

Body Sensor Networks (BSNs) offer a cost-effective way to monitor patients’ health and detect potential risks. Despite the growing interest attracted by BSNs, there is a lack of testing approaches for them. Testing a Body Sensor Network (BSN) is challenging due to its evolving nature, the complexity of sensor scenarios and their fusion, the potential necessity of third-party testing for certification, and the need to prioritize critical failures given limited resources. This paper addresses these challenges by proposing three BSN testing approaches: PASTA, ValComb, and TransCov. These approaches share common characteristics, which are described through a general framework called GATE4BSN. PASTA simulates patients with sensors and models sensor trends using a Discrete Time Markov Chain (DTMC). ValComb explores various health conditions by considering all sensor risk level combinations, while TransCov ensures full coverage of DTMC transitions. We empirically evaluate these approaches, comparing them with a baseline approach in terms of failure detection. The results demonstrate that PASTA, ValComb, and TransCov uncover previously undetected failures in an open-source BSN and outperform the baseline approach. Statistical analysis reveals that PASTA is the most effective, while ValComb is 76 times faster than PASTA and nearly as effective.

We are increasingly surrounded by systems connecting us with the digital world and facilitating our life by supporting our work, leisure, activities at home, health, and so on. These systems are pressed by two forces. On the one side, they operate in environments that are increasingly challenging due to uncertainty and uncontrollability. On the other side, they need to evolve, often in a continuous fashion, to meet changing needs, to offer new functionalities, or also to fix emerging failures. To make the picture even more complex, these systems rarely work in isolation and often need to collaborate with other systems, as well as humans. All such facets call for moving their validation during operation, as offered by approaches called testing in the field. In this article, we observe that even the field-based testing approaches should change over time to follow and adapt to the changes and evolution of collaborating systems or environments or users’ behaviors. We provide a taxonomy of this new category of testing that we call self-adaptive testing in the field (SATF) , together with a reference architecture for SATF approaches. To achieve this objective, we surveyed the literature and collected feedback and contributions from experts in the domain via a questionnaire and interviews.

The importance of software architecture is largely recognized also in iterative and agile development settings. However, it is quite complex to provide evidence that an architecture is of good quality and that the architectural decisions are appropriate, correct, or optimal. Architecture evaluation aims at showing and providing confidence that design decisions contribute to fulfilling the stakeholder concerns. Some architecture evaluation methods are scenario-based and aim at balancing many potentially conflicting quality attributes. Other works focus on a specific quality attribute and provide metrics to measure it.In this paper we survey the state of the art in metrics for evaluating quality attributes of architectures. The elicited metrics are organized into a catalog, which associates them with the specific quality attributes they aim to measure. We contribute also an MDE framework that generates web views facilitating the analysis of architectures. In this way, researchers and practitioners can easily retrieve the metrics that are appropriate to their specific needs. The catalog of metrics and quality attributes is released to the research community and open to contributions from experts and practitioners.

Testing in the field is gaining momentum, as a means to detect those failures that escape in-house testing by continuing the testing even while a system is operating in production. Among several approaches that are proposed, this paper focuses on the important notion of self-adaptivity of testing in the field, as such techniques need to adapt in many ways their strategy to the context and the emerging behaviors of the system under test. In this work, we investigate the topic by conducting a scoping review of the literature on self-adaptive testing in the field. We rely on a taxonomy organized in some categories that include the object to adapt, the adaptation trigger, the temporal characteristics, the realization issues, the interaction concerns, the type of field-based approach, and the impact/cost. Our study sheds light on self-adaptive testing in the field by identifying related key concepts and key characteristics and extracting some knowledge gaps to better guide future research.

Face Recognition is one of the most relevant problems in computer vision as we consider its importance to areas such as surveillance, forensics and psychology. Furthermore, open-set face recognition has a large room for improvement since only few researchers have focused on it. In fact, a real-world recognition system has to cope with several unseen individuals and determine whether a given face image is associated with a subject registered in a gallery of known individuals. In this work, we combine hashing functions and classification methods to estimate when probe samples are known (i.e., belong to the gallery set). We carry out experiments with partial least squares and neural networks and show how response value histograms tend to behave for known and unknown individuals whenever we test a probe sample. In addition, we conduct experiments on FRGCv1, PubFig83 and VGGFace to show that our method continues effective regardless of the dataset difficulty.