Abstract
Understanding people's face-to-face interactions is crucial for effective infectious disease management. Traditional contact tracing, often relying on interviews or smartphone applications, faces limitations such as incomplete recall, low adoption rates, and privacy concerns. This study proposes utilizing anonymized Call Detail Records (CDRs) as a substitute for in-person meetings. We assume that when two individuals engage in a phone call connected to the same cell tower, they are likely to meet shortly thereafter. Testing this assumption, we evaluated two hypotheses. The first hypothesis-that such co-located interactions occur in a workplace setting-achieved 83% agreement, which is considered a strong indication of reliability. The second hypothesis-that calls made during these co-location events are shorter than usual-achieved 86% agreement, suggesting an almost perfect reliability level. These results demonstrate that CDR-based co-location events can serve as a reliable substitute for in-person interactions and thus hold significant potential for enhancing contact tracing and supporting public health efforts.

Abstract
Mobile devices have become integral to our everyday lives, yet their utility hinges on their battery life. In Android apps, resource leaks caused by inefficient resource management are a significant contributor to battery drain and poor user experience. Our work introduces Alpakka, a source-to-source compiler for Android's Smali syntax. To showcase Alpakka's capabilities, we developed an Alpakka library capable of detecting and automatically correcting resource leaks in Android APK files. We demonstrate Alpakka's effectiveness through empirical testing on 124 APK files from 31 real-world Android apps in the DroidLeaks [12] dataset. In our analysis, Alpakka identified 93 unique resource leaks, of which we estimate 15% are false positives. From these, we successfully applied automatic corrections to 45 of the detected resource leaks.

Abstract
WebAssembly (Wasm) has emerged as a powerful binary format, enabling the seamless integration of languages like C and Rust into web applications. JavaScript (JS), the dominant language for client-side web development, has its code susceptible to tampering and intellectual property theft due to its transparency in browser environments. We introduce TranspileJS, a novel tool designed to enhance code security by automatically selecting and translating JS snippets into Wasm. TranspileJS leverages a multi-stage architecture that converts JS to TypeScript, which is compiled into Wasm using the AssemblyScript compiler. TranspileJS addresses the challenges posed by the fundamental differences between JS and Wasm, including dynamic typing, runtime behaviour mismatches, and standard library discrepancies, ensuring that the original behaviour of the code is preserved while maximising the amount of code transpiled. Our experiments show that TranspileJS successfully transpiles approximately one-third of the code in our dataset, with a performance impact of up to a 12.3% increase in execution time. The transpilation process inherently obfuscates code, creating effects similar to standard obfuscation techniques, and generates a stealthy and resilient output. Furthermore, combining transpilation with WebAssembly-specific obfuscation techniques opens new possibilities for code protection and resistance against reverse engineering.

Abstract
The rapid proliferation of Edge AI applications demands efficient, low-power computing architectures tailored to specific workloads. The RISC-V ecosystem is a promising solution, and has led to a fast growth of implementations based on custom instructions extensions, but with varying degrees of functionality and support which may hinder easy adoption. In this paper, we extensively review existing RISC-V extensions targeting primarily the AI domain and respective compilation flows, highlighting challenges in deployment, usability, and compatibility. We further implement and provide usable containerized environments for two of these works. To address the identified challenges, we then propose an approach for lightweight early validation of custom instructions via source-to-source transformations, without need of compiler modifications. We target our own Single Instruction Multiple Data (SIMD) accelerator, which we integrate into a CORE-V cv32e40px baseline core through custom instructions, and versus which we achieve up to 11.9x speedup for matrix-vector operations.

Abstract
Code comprehension is often supported by source code analysis tools that provide more abstract views over software systems, such as those detecting design patterns. These tools encompass analysis of source code and ensuing extraction of relevant information. However, the analysis of the source code is often specific to the target programming language. We propose DP-LARA, a multilanguage pattern detection tool that uses the multilanguage capability of the LARA framework to support finding pattern instances in a code base. LARA provides a virtual AST, which is common to multiple OOP programming languages, and DP-LARA then performs code analysis of detecting pattern instances on this abstract representation. We evaluate the detection performance and consistency of DP-LARA with a few software projects. Results show that a multilanguage approach does not compromise detection performance, and DP-LARA is consistent across the languages we tested it for (i.e., Java and C/C++). Moreover, by providing a virtual AST as the abstract representation, we believe to have decreased the effort of extending the tool to new programming languages and maintaining existing ones.

Abstract
Executing Artificial Intelligence (AI) at the edge is challenging due to tight energy and computational constraints. Heterogeneous platforms, particularly those incorporating Coarse-Grained Reconfigurable Arrays (CGRAs), offer a compelling trade-off between hardware specialization and programmability, supporting spatially distributed and energyefficient computation. Despite their potential, the deployment of applications on CGRA accelerators remains limited by the lack of practical toolchains and methodologies. In this work, we propose a compilation flow based on MLIR to enable the seamless integration of both C/C++ kernels and ONNX-based AI models into a RISC-V system augmented with a CGRA accelerator. Our approach extracts the underlying Data Flow Graph (DFG) from the high-level representation. It maps it onto the CGRA using an Integer Linear Programming (ILP) mapper that accounts for the accelerator's architectural constraints. A custom backend completes the toolchain by generating the necessary binaries for coordinated execution across the RISC-V processor and the CGRA. This framework enables the practical deployment of heterogeneous edge workloads, combining the flexibility of software execution with the efficiency of hardware acceleration. © 2025 IEEE.