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Li Jian

Publications and source records attributed to Li Jian.

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Research on Driving Scenario Technology Based on Multimodal Large Lauguage Model Optimization

With the advancement of autonomous and assisted driving technologies, higher demands are placed on the ability to understand complex driving scenarios. Multimodal general large models have emerged as a solution for this challenge. However, applying these models in vertical domains involves difficulties such as data collection, model training, and deployment optimization. This paper proposes a comprehensive method for optimizing multimodal models in driving scenarios, including cone detection, traffic light recognition, speed limit recommendation, and intersection alerts. The method covers key aspects such as dynamic prompt optimization, dataset construction, model training, and deployment. Specifically, the dynamic prompt optimization adjusts the prompts based on the input image content to focus on objects affecting the ego vehicle, enhancing the model's task-specific focus and judgment capabilities. The dataset is constructed by combining real and synthetic data to create a high-quality and diverse multimodal training dataset, improving the model's generalization in complex driving environments. In model training, advanced techniques like knowledge distillation, dynamic fine-tuning, and quantization are integrated to reduce storage and computational costs while boosting performance. Experimental results show that this systematic optimization method not only significantly improves the model's accuracy in key tasks but also achieves efficient resource utilization, providing strong support for the practical application of driving scenario perception technologies.

cs.CV

Acoustic Three-dimensional Chern Insulators with Arbitrary Chern Vectors

The Chern vector is a vectorial generalization of the scalar Chern number, being able to characterize the topological phase of three-dimensional (3D) Chern insulators. Such a vectorial generalization extends the applicability of Chern-type bulk-boundary correspondence from one-dimensional (1D) edge states to two-dimensional (2D) surface states, whose unique features, such as forming nontrivial torus knots or links in the surface Brillouin zone, have been demonstrated recently in 3D photonic crystals. However, since it is still unclear how to achieve an arbitrary Chern vector, so far the surface-state torus knots or links can emerge, not on the surface of a single crystal as in other 3D topological phases, but only along an internal domain wall between two crystals with perpendicular Chern vectors. Here, we extend the 3D Chern insulator phase to acoustic crystals for sound waves, and propose a scheme to construct an arbitrary Chern vector that allows the emergence of surface-state torus knots or links on the surface of a single crystal. These results provide a complete picture of bulk-boundary correspondence for Chern vectors, and may find use in novel applications in topological acoustics.

physics.app-ph

Multi-party Semi-quantum Secret Sharing Protocol based on Measure-flip and Reflect Operations

Semi-quantum secret sharing (SQSS) protocols serve as fundamental frameworks in quantum secure multi-party computations, offering the advantage of not requiring all users to possess intricate quantum devices. However, the current landscape of SQSS protocols predominantly caters to bipartite scenarios, rendering them inadequate for practical multi-party secret sharing requirements. Addressing this gap, this paper proposes a novel SQSS protocol based on multi-particle GHZ states. In this protocol, the quantum user distributes predetermined secret information to multiple classical users with limited quantum capabilities, necessitating collaborative efforts among all classical users to reconstruct the correct secret information. By utilizing measure-flip and reflect operations, the transmitted multi-particle GHZ states can all contribute keys, thereby improving the utilization of transmitted particles. Security analysis shows that the protocol's resilience against prevalent external and internal threats. Additionally, employing IBM Qiskit, we conduct quantum circuit simulations to validate the protocol's accuracy and feasibility. Compared with similar studies, the proposed protocol has advantages in terms of protocol scalability, qubit efficiency, and shared message types.

quant-ph

The hard X-ray shortages prompted by the clock bursts in GS 1826--238

We report on a study of GS 1826--238 using all available {\it RXTE} observations, concentrating on the behavior of the hard X-rays during type-I bursts. We find a hard X-ray shortage at 30--50 keV promoted by the shower of soft X-rays coming from type-I bursts. This shortage happens with a time delay after the peak of the soft flux of 3.6 $\pm$ 1.2 seconds.The behavior of hard X-rays during bursts indicates cooling and reheating of the corona, during which a large amount of energy is required. We speculate that this energy originates from the feedback of the type-I bursts to the accretion process, resulting in a rapid temporary increase of the accretion rate.

astro-ph.HE

More Efficient Algorithms and Analyses for Unequal Letter Cost Prefix-Free Coding

There is a large literature devoted to the problem of finding an optimal (min-cost) prefix-free code with an unequal letter-cost encoding alphabet of size. While there is no known polynomial time algorithm for solving it optimally there are many good heuristics that all provide additive errors to optimal. The additive error in these algorithms usually depends linearly upon the largest encoding letter size. This paper was motivated by the problem of finding optimal codes when the encoding alphabet is infinite. Because the largest letter cost is infinite, the previous analyses could give infinite error bounds. We provide a new algorithm that works with infinite encoding alphabets. When restricted to the finite alphabet case, our algorithm often provides better error bounds than the best previous ones known.

cs.IT