Xueqi Dang

Yinghua Li, Xueqi Dang, Haoye Tian et al.

The integration of artificial intelligence (AI) into mobile applications has significantly transformed various domains, enhancing user experiences and providing personalized services through advanced machine learning (ML) and deep learning (DL) technologies. AI-driven mobile apps typically refer to applications that leverage ML/DL technologies to perform key tasks such as image recognition and natural language processing. In this paper, we conducted the most extensive empirical study on AI applications, exploring on-device ML apps, on-device DL apps, and AI service-supported (cloud-based) apps. Our study encompasses 56,682 real-world AI applications, focusing on three crucial perspectives: 1) Application analysis, where we analyze the popularity of AI apps and investigate the update states of AI apps; 2) Framework and model analysis, where we analyze AI framework usage and AI model protection; 3) User analysis, where we examine user privacy protection and user review attitudes. Our study has strong implications for AI app developers, users, and AI R\&D. On one hand, our findings highlight the growing trend of AI integration in mobile applications, demonstrating the widespread adoption of various AI frameworks and models. On the other hand, our findings emphasize the need for robust model protection to enhance app security. Additionally, our study highlights the importance of user privacy and presents user attitudes towards the AI technologies utilized in current AI apps. We provide our AI app dataset (currently the most extensive AI app dataset) as an open-source resource for future research on AI technologies utilized in mobile applications.

Wendkûuni C. Ouédraogo, Yinghua Li, Xueqi Dang et al.

Search-based test generation tools such as EvoSuite produce compilable and high-coverage unit tests at scale, but their suites are often hard to read and maintain. LLMs can generate more natural tests, yet direct generation remains brittle, with compilation rates of only 51-78% in our study. We introduce TestHumanizer, a hybrid SBST+LLM approach that uses LLMs as controlled refactoring layers over compilable SBST suites to improve naming, structure, and developer-oriented clarity while preserving behavior and compilation validity. We evaluate TestHumanizer on 350 classes from Defects4J and SF110. EvoSuite generates 15 suites per class, and each suite is refactored under three context configurations using gpt-4o and mistral-large-2407, yielding 31,500 refactorings. TestHumanizer reaches 88-98% compilation rates, close to EvoSuite's 100% baseline and clearly above direct LLM generation. Structural coverage is largely preserved, typically within 1-2 percentage points, and 86-95% of refactorings satisfy a composite faithful-refactoring threshold. Refactored suites also improve predicted readability, reduce control-flow and cognitive complexity, and mitigate structural smells. The summary-based setting offers the most robust trade-off, while long code-centric prompts are more prone to hallucination-induced failures. A developer study on 30 classes and 444 test methods confirms significant gains in perceived readability and willingness to adopt, with Wilcoxon p less than 0.01 and substantial inter-rater agreement. Overall, LLMs are most effective not as standalone generators but as validation-gated refinement layers over robust SBST outputs.