Large Language Models (LLMs) have been increasingly adopted in a wide range of applications, many of which require long-running inference processes. However, these systems may be subject to software aging phenomena, leading to progressive performance degradation and potential failures. In this work, we experimentally investigate memory-related software aging in LLM inference. We performed 48-hour experiments with three open-source models (Pythia, OPT, and GPT-Neo) under low, medium, and high workloads, monitoring memory consumption at both system and process levels. Using the Mann–Kendall test and Sen’s slope estimator, we observed monotonic growth in RAM usage across all models on Central Processing Units (CPUs), with OPT presenting the steepest slopes. Process-level analysis further revealed that LLM processes were the primary contributors to memory growth, along with background services. Additionally, we conducted identical experiments on Graphics Processing Units (GPUs). Unlike the experiments without a GPU, GPU-based experiments revealed bounded oscillations and abrupt resets likely due to driver-level memory management, while host RAM and process-level monitoring still revealed clear symptoms of aging. These findings demonstrate that software aging manifests differently across execution environments, reinforcing the need for environment-specific monitoring approaches.

LCL filters are widely used to connect a renewable electrical power source to the electrical grid. The optimal power transfer to the grid depends on the tracking of a sinusoidal current reference synchronized to the grid voltage. However, the tracking of that reference is a difficult task. On the other hand, the sinusoidal reference can be considered as composed of a set of polynomials of different degrees. Thus, this paper explores the application of polynomial reference tracking generalized predictive controller (Poly-GPC) to control the output current of the LCL filter connected to an AC grid. Different tests using the Poly-GPC with different polynomial reference degrees were performed to verify the relationship between the polynomial degree used to approximate the sinusoidal reference with the control accuracy. Simulation results show that the Poly-GPC can be used to control an LCL filter. An analysis of the effect of the polynomial order used to approximate the sinusoidal reference in the current reference tracking is done. The Poly-GPC adds integrators to the control system to reduce the tracking error. It was observed that adding too many integrators may create instability. However, a low number of integrators reduces the tracking performance.

It is difficult to maintain consistency between artifacts produced during the development of mechatronic systems, and to ensure the successful integration of independently developed parts. The difficulty stems from the complex, multidisciplinary nature of the problem, with multiple artifacts produced by each engineering domain, throughout the design process, and across supplier chains. In this work, we develop a methodology and a tool, CONDEnSe, that given a set of Assume/Guarantee (A/G) contracts that capture the system requirements, and a high-level decomposition of the system model, automatically generates design variants that respect the requirements and exports those variants to different engineering tools for analysis. Our methodology makes use of a contract-based design algebra to ensure that all generated artifacts for all design variants are consistent by construction, even when the process is modularized and independently developed parts are only later integrated. In contrast with previous work, our approach reduces the search space to models that comply with the captured design requirements.

We present ParTypes, a type-based methodology for the verification of Message Passing Interface (MPI) programs written in the C programming language. The aim is to statically verify programs against protocol specifications, enforcing properties such as fidelity and absence of deadlocks. We develop a protocol language based on a dependent type system for message-passing parallel programs, which includes various communication operators, such as point-to-point messages, broadcast, reduce, array scatter and gather. For the verification of a program against a given protocol, the protocol is first translated into a representation read by VCC, a software verifier for C. We successfully verified several MPI programs in a running time that is independent of the number of processes or other input parameters. This contrasts with alternative techniques, notably model checking and runtime verification, that suffer from the state-explosion problem or that otherwise depend on parameters to the program itself. We experimentally evaluated our approach against state-of-the-art tools for MPI to conclude that our approach offers a scalable solution.