LEAP: Efficient and Automated Test Method for NLP Software

The widespread adoption of DNNs in NLP software has highlighted the need for robustness. Researchers proposed various automatic testing techniques for adversarial test cases. However, existing methods suffer from two limitations: weak error-discovering capabilities, with success rates ranging from 0% to 24.6% for BERT-based NLP software, and time inefficiency, taking 177.8s to 205.28s per test case, making them challenging for time-constrained scenarios. To address these issues, this paper proposes LEAP, an automated test method that uses LEvy flight-based Adaptive Particle swarm optimization integrated with textual features to generate adversarial test cases. Specifically, we adopt Levy flight for population initialization to increase the diversity of generated test cases. We also design an inertial weight adaptive update operator to improve the efficiency of LEAP's global optimization of high-dimensional text examples and a mutation operator based on the greedy strategy to reduce the search time. We conducted a series of experiments to validate LEAP's ability to test NLP software and found that the average success rate of LEAP in generating adversarial test cases is 79.1%, which is 6.1% higher than the next best approach (PSOattack). While ensuring high success rates, LEAP significantly reduces time overhead by up to 147.6s compared to other heuristic-based methods. Additionally, the experimental results demonstrate that LEAP can generate more transferable test cases and significantly enhance the robustness of DNN-based systems.Comment: Accepted at ASE 202

1-(2-Chloro­benzyl­idene)-2-(2,4-dinitro­phen­yl)hydrazine

In the title compound, C13H9ClN4O4, there are two crystallographically independent mol­ecules in the asymmetric unit, which have very similar conformations. The C=N—N angles in each independent mol­ecule are 115.0 (2) and 116.6 (2)°, which are significantly smaller than the ideal value of 120° expected for sp 2-hybridized N atoms. This is probably a consequence of repulsion between the nitro­gen lone pairs and the adjacent N—N bonds. Two bifurcated intra­molecular N—H⋯O hydrogen bonds help to establish the mol­ecular conformation and consolidate the crystal packing

6-Cyclo­hexyl­meth­yl-5-ethyl-2-[(2-oxo-2-phenyl­eth­yl)sulfan­yl]pyrimidin-4(3H)-one

In the title compound, C21H26N2O2S, the cyclo­hexane ring adopts a chair conformation. The angle at the methyl­ene bridge linking the pyrimidine and cyclo­hexane rings is 113.41 (13)°. This is in the range considered optimal for maximum activity of non-nucleoside reverse transcriptase inhibitors. In the crystal, mol­ecules are connected into centrosymmetric dimers via pairs of N—H⋯O hydrogen bonds