Urban vehicle emissions are one of the main contributors to air pollution since most vehicles still rely on fossil fuels, despite the growing popularity of alternative options, such as hybrids and electric cars. Recently, artificial intelligence (AI) and automation-based controllers have gained attention for their potential use in adaptive traffic signal control. Many studies have been conducted on the application of deep reinforcement learning (DRL) models to reduce travel time in adaptive traffic signal control. However, limited research has been done on adapting traffic signal control to reduce CO2 emissions and fuel consumption in urban vehicles. As such, this work proposes a digital-twin-based adaptive traffic signal control approach that relies on a digital twin (DT) of urban traffic network and uses the DRL multiagent deep deterministic policy gradient (MADDPG) to optimize for reduced fuel consumption and CO2 emission. The system is designed to simulate different traffic scenarios and control strategies, enabling for adaptation in traffic signal adjustments. To assess the effectiveness and applicability of the proposed approach, a quantitative simulation is performed using synthetic and real-world traffic data sets from a multi-intersection network in a neighborhood in Amman, Jordan, during peak hours. The findings suggest that the DRL approach based on DTs on synthetic networks can reduce CO2 emissions and fuel consumption even when using a basic reward function based on stopped vehicles.

Context: Evaluating software architectures in uncertain environments raises new challenges, which require continuous approaches. We define continuous evaluation as multiple evaluations of the software architecture that begins at the early stages of the development and is periodically and repeatedly performed throughout the lifetime of the software system. Numerous approaches have been developed for continuous evaluation; to handle dynamics and uncertainties at run-time, over the past years, these approaches are still very few, limited, and lack maturity. Objective: This review surveys efforts on architecture evaluation and provides a unified terminology and perspective on the subject. Method: We conducted a systematic literature review to identify and analyse architecture evaluation approaches for uncertainty including continuous and non-continuous, covering work published between 1990–2020. We examined each approach and provided a classification framework for this field. We present an analysis of the results and provide insights regarding open challenges. Major results and conclusions: The survey reveals that most of the existing architecture evaluation approaches typically lack an explicit linkage between design-time and run-time. Additionally, there is a general lack of systematic approaches on how continuous architecture evaluation can be realised or conducted. To remedy this lack, we present a set of necessary requirements for continuous evaluation and describe some examples.

Design-time evaluation is essential to build the initial software architecture to be deployed. However, experts’ assumptions made at design-time are unlikely to remain true indefinitely in systems that are characterized by scale, hyperconnectivity, dynamism, and uncertainty in operations (e.g. IoT). Therefore, experts’ design-time decisions can be challenged at run-time. A continuous architecture evaluation that systematically assesses and intertwines design-time and run-time decisions is thus necessary. This paper proposes the first proactive approach to continuous architecture evaluation of the system leveraging the support of simulation. The approach evaluates software architectures by not only tracking their performance over time, but also forecasting their likely future performance through machine learning of simulated instances of the architecture. This enables architects to make cost-effective informed decisions on potential changes to the architecture. We perform an IoT case study to show how machine learning on simulated instances of architecture can fundamentally guide the continuous evaluation process and influence the outcome of architecture decisions. A series of experiments is conducted to demonstrate the applicability and effectiveness of the approach. We also provide the architect with recommendations on how to best benefit from the approach through choice of learners and input parameters, grounded on experimentation and evidence.

Crying is a newborn’s main way of communicating. Despite their apparent similarity, newborn cries are physically generated and have distinct characteristics. Experienced medical professionals, nurses, and parents are able to recognize these variations based on their prior interactions. Nonetheless, interpreting a baby’s cries can be challenging for carers, first-time parents, and inexperienced paediatricians. This paper uses advanced deep learning techniques to propose a novel approach for baby cry classification. This study aims to accurately classify different cry types associated with everyday infant needs, including hunger, discomfort, pain, tiredness, and the need for burping. The proposed model achieves an accuracy of 98.33%, surpassing the performance of existing studies in the field. IoT-enabled sensors are utilized to capture cry signals in real time, ensuring continuous and reliable monitoring of the infant’s acoustic environment. This integration of IoT technology with deep learning enhances the system’s responsiveness and accuracy. Our study highlights the significance of accurate cry classification in understanding and meeting the needs of infants and its potential impact on improving infant care practices. The methodology, including the dataset, preprocessing techniques, and architecture of the deep learning model, is described. The results demonstrate the performance of the proposed model, and the discussion analyzes the factors contributing to its high accuracy.

Blockchainsand smart contracts are pivotal in transforming interactions between systems and individuals, offering secure, immutable, and transparent trust-building mechanisms without central oversight. However, Smart Contracts face limitations due to their reliance on blockchain-contained data, a gap addressed by ’Oracles’. These bridges to external data sources introduce the ’Oracle problem’, where maintaining blockchain-like security and transparency becomes vital to prevent data integrity issues. This paper presents Veritas, a novel decentralized oracle system leveraging a layer-2 scaling solution, enhancing smart contracts’ efficiency and security on Ethereum blockchains. The proposed architecture, explored through simulation and experimental analyses, significantly reduces operational costs while maintaining robust security protocols. An innovative node selection process is also introduced to minimize the risk of malicious data entry, thereby reinforcing network security. Veritas offers a solution to the Oracle problem by aligning with blockchain principles of security and transparency, and demonstrates advancements in reducing operational costs and bolstering network integrity. While the study provides a promising direction, it also highlights potential areas for further exploration in blockchain technology and oracle system optimization.