arXiv subjects

Jianfei Tang

Publications and source records attributed to Jianfei Tang.

3 recordsLinked to original sources

arXiv2026

MACAA: Belief-Revision Multi-Agent Reasoning for Code Authorship Verification

Code authorship attribution (CAA) supports software forensics, plagiarism detection, and intellectual property protection. However, existing supervised CAA approaches suffer from scarce training data and closed-world assumptions: they require sufficient labeled code from fixed candidate-author sets, making training difficult in low-data cases and predictions unreliable for open-world test pairs with unseen samples, or heterogeneous code pairs. Large language models remove task-specific training, but direct prompting depends on costly expert-designed prompts, can hallucinate over complex heterogeneous code pairs, and rarely yields auditable evidence traces. We propose MACAA, a belief-revision-based multi-agent framework for training-free code authorship verification. MACAA comprises a Coordinator and four Expert Agents analyzing layout, lexical, syntactic, and programming-pattern evidence. The Coordinator gathers expert signals for expansion, discounts unreliable evidence through contraction, and resolves conflicts through revision to preserve belief consistency, replacing direct LLM judgment with auditable hypothesis refinement. MACAA achieves 89.15\% F1 on same-language benchmarks and 80.00\% on mixed cross-language pairs, outperforming the baselines overall in both same-language and cross-language evaluations.

cs.SE↗

arXiv2025

Study of Four nulling pulsars with FAST

We present an analysis of 4 nulling pulsars with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). For PSR J1649+2533, our results suggest mode changing rather than subpulse drifting as previously reported at lower frequencies. For PSR J1752+2359, we confirm its quasi-periodic switching between distinct emission states, but further show that the so-called "quasi-null" or "RRAT-like" state actually consists of persistent low-level emission superposed with occasional bright pulses. For PSR J1819+1305, our data confirm the modulation reported earlier, while additional weaker features are also seen. For PSR J1916+1023, we detect both nulling and subpulse drifting, but find no clear evidence of direct interaction between them. These results provide new insights into the diverse manifestations of pulsar nulling, highlight the capability of FAST to detect subtle emission states, and add to the growing body of work on pulsar emission variability.

astro-ph.HE↗

arXiv2014

Excitation of Langmuir waves by the lower energy cutoff behavior of power-law electrons

Langmuir waves (LWs), which are believed to play a crucial role in the plasma emission of solar radio bursts, can be excited by streaming instability of energetic electron beams. However, solar hard X-ray observations imply that the energetic flare electrons usually have a power-law energy distribution with a lower energy cutoff. In this paper, we investigate LWs driven by the power-law electrons. The results show that power-law electrons with the steepness cutoff behavior can excite LWs effectively because of the population inversion distribution below the cutoff energy ($E_c$). The growth rate of LWs increases with the steepness index ($δ$) and decreases with the power-law index ($α$). The wave number of the fastest growing LWs ($kλ_D$), decreases with the characteristic velocity of the power-law electrons ($v_{c}=\sqrt{2E_{c}/m_{e}}$) and increases with the thermal velocity of ambient electrons ($v_T$). This can be helpful for us to understand better the physics of LWs and the dynamics of energetic electron beams in space and astrophysical plasmas.

astro-ph.SR↗