During February 2025, Cyifan focused on improving the timing accuracy of the light detection module in the DUNE/larnd-sim repository. Addressing a critical simulation issue, Cyifan corrected the impulse tick size from 0.001 to 0.01 microseconds, ensuring that light signal timing in the simulation aligns with physical expectations. This Python-based fix required a strong understanding of both physics and simulation principles, as it directly impacted the fidelity of event reconstruction and downstream analyses. While no new features were introduced, the work demonstrated careful attention to simulation detail and contributed to more reliable results for physics research using larnd-sim.