SearcharxivSearch

arXiv subjects

Yibing Huang

Publications and source records attributed to Yibing Huang.

4 recordsLinked to original sources

MT-Video-Bench: A Holistic Video Understanding Benchmark for Evaluating Multimodal LLMs in Multi-Turn Dialogues

The recent development of Multimodal Large Language Models (MLLMs) has significantly advanced AI's ability to understand visual modalities. However, existing evaluation benchmarks remain limited to single-turn question answering, overlooking the complexity of multi-turn dialogues in real-world scenarios. To bridge this gap, we introduce MT-Video-Bench, a holistic video understanding benchmark for evaluating MLLMs in multi-turn dialogues. Specifically, our MT-Video-Bench mainly assesses 6 core competencies that focus on perceptivity and interactivity, encompassing 1,000 meticulously curated multi-turn dialogues from diverse domains. These capabilities are rigorously aligned with real-world applications, such as interactive sports analysis and multi-turn video-based intelligent tutoring. With MT-Video-Bench, we extensively evaluate various state-of-the-art open-source and closed-source MLLMs, revealing their significant performance discrepancies and limitations in handling multi-turn video dialogues. The benchmark will be publicly available to foster future research.

cs.CV

Phase estimation of Mach-Zehnder interferometer via Laguerre excitation squeezed state

Quantum metrology has an important role in the fields of quantum optics and quantum information processing. Here we introduce a kind of non-Gaussian state, Laguerre excitation squeezed state as input of traditional Mach-Zehnder interferometer to examine phase estimation in realistic case. We consider the effects of both internal and external losses on phase estimation by using quantum Fisher information and parity detection. It is shown that the external loss presents a bigger effect than the internal one. The phase sensitivity and the quantum Fisher information can be improved by increasing the photon number and even surpass the ideal phase sensitivity by two-mode squeezed vacuum in a certain region of phase shift for realistic case.

quant-ph

Stable, predictable and training-free operation of superconducting Bi-2212 Rutherford cable racetrack coils at the very high wire current density of more than 1000 A/mm2

High-temperature superconductors (HTS) could enable high-field magnets much stronger than is possible with Nb-Ti and Nb3Sn, but two key limiting factors have so far been the difficulty of achieving high critical current density in long-length conductors, especially in high-current cables, and the danger of quenches out of the superconducting into the normal state. Here we demonstrate stable, reliable and training-quench-free performance of Bi-2212 racetrack coils wound with a 17-strand Rutherford cable fabricated from wires made with nanospray Bi-2212 powder. These multifilament wires are now being delivered in single lengths of more than 1 km with a new record whole-wire critical current density up to 950 A/mm2 at 30 T at 4.2 K. These coils carried up to 8.6 kA while generating a peak field of 3.5 T at 4.2 K, at a wire current density of 1020 A/mm2. Quite different from the unpredictable training performance of Nb-Ti and Nb3Sn magnets, these Bi-2212 magnets showed no training quenches and entered the flux flow state in a stable manner before thermal runaway and quench occurred. Also quite different from Nb-Ti, Nb3Sn, and REBCO magnets for which localized thermal runaways occur at unpredictable locations, the quenches of Bi-2212 magnets consistently occurred in the high field regions over a conductor length greater than one meter. These characteristics make quench detection rather simple, enabling safe protection, and suggest a new paradigm of constructing quench-predictable superconducting magnets from Bi-2212, which is, like Nb-Ti and Nb3Sn, isotropic, round, multifilament, uniform over km lengths and suitable for Rutherford cable use but, unlike them, much more tolerant of the energy disturbances that often lead Nb-based superconducting magnets to premature quench and long training cycles.

cond-mat.supr-con

Reduction of gas bubbles and improved critical current density in Bi-2212 round wire by swaging

Bi-2212 round wire is made by the powder-in-tube technique. An unavoidable property of powder-in-tube conductors is that there is about 30% void space in the as-drawn wire. We have recently shown that the gas present in the as-drawn Bi-2212 wire agglomerates into large bubbles and that they are presently the most deleterious current limiting mechanism. By densifying short 2212 wires before reaction through cold isostatic pressing (CIPping), the void space was almost removed and the gas bubble density was reduced significantly, resulting in a doubled engineering critical current density (JE) of 810 A/mm2 at 5 T, 4.2 K. Here we report on densifying Bi-2212 wire by swaging, which increased JE (4.2 K, 5 T) from 486 A/mm2 for as-drawn wire to 808 A/mm2 for swaged wire. This result further confirms that enhancing the filament packing density is of great importance for making major JE improvement in this round-wire magnet conductor.

cond-mat.supr-con