Although Vision Language Models (VLMs) have excelled at image and video understanding, applying them to hour-long videos is held back by two interrelated challenges: exorbitant computational expense and a qualitative breakdown in long-term temporal reasoning. Thus, models tend to generate answers based on speculation instead of solid visual facts, causing both factually incorrect and plausible hallucinations. This problem is compounded by current benchmarks that, by only emphasizing final answers, lack an effective mechanism to check whether reasoning is substantiated by specific visual evidence. This makes it hard to differentiate between true understanding and pretend comprehension, inhibiting targeted model refinement. To address these interrelated challenges of model fragility and evaluation weakness, we adopt a twofold strategy. First, we present EV²-Bench, a large-scale benchmark that breaks new ground by an evaluation paradigm built upon spatio-temporal visual evidence, forcing models to justify answers with checkable hints. Second, we put forward DynamicSelect, an adaptive token compression system that efficiently condenses salient information by a dynamic semantic selector and a hierarchical compression strategy. Comprehensive experiments demonstrate that DynamicSelect significantly outperforms the baselines on EV²-Bench as well as other public benchmarks. Our study offers not only a more effective approach to long-video understanding but also a more stringent evaluation paradigm, indicating the way toward more robust models.

Efficient and reliable dynamic modelling and analysis is critical to the shape control and estimate of a backbone continuum manipulator. This paper presents a novel dynamic modelling method to investigate the deformation modal properties of a vertical stretch-retractable continuum manipulator (VSRCM) under the tip horizontal load. Based on the equivalence of the elastic bending potential energy, this method simplifies the backbone continuum manipulator to a single beam, an equivalent-guided beam (EGB). One end of the EGB is fixed, and the other end is guided. The modal dynamics model of the EGB is then established by employing the vibration theory of a continuous beam, and the modal properties of the continuum manipulator are analyzed. Static and Dynamic experiments of the VSRCM are performed to validate the dynamic modeling method through the comparison and analysis of the free dynamic response and frequency properties of the continuum manipulator. To analyze the free dynamic response, the large deflection static model with tip horizontal load is also established based on the elliptic integral approach. Experimental results and comparison demonstrate that the static model is efficient and precise to predict the large deformation, and the modal dynamic models well reflect the actual vibration modal characteristics of the VSRCM.

Considering the characteristic of irrigation in the rural area of China, this paper brings forward new devices based on GSM (global system mobile) network and radio communication. Three levels are included: the PC control platform or common cell phone for surveillance, the controller and the action unit. Simple GSM modules are available in the PC control platform and the controller. Orders can be sent from the PC control platform or cell phone to the controller and the information such as temperature, soil moisture and air humidity sampled by the controller can also be sent to the PC platform or cell phone by GSM message. Emitter and receiver of short-wave radio are embedded in the controller and the action unit respectively. Radio communication works between the controller and the action units. Database of spot information sampled can be analyzed and browsed by friendly interface in PC. The devices have been installed in some farms of Beijing, capital of China, and Xinjiang, northwest of China