Search

Savonius hydrokinetic turbines (SHTs), categorized as emerging cyclic-type wave energy converters (WECs), have demonstrated notable potential in achieving elevated energy conversion efficiency and consistent power output. This performance is particularly observed when operating under the initial phase-locked strategy (IPLS), marking a significant advancement in the realm of wave energy harvesting. However, a thorough exploration of the influences stemming from wave conditions and turbine design remains an area that warrants further investigation for advancing the performance of SHT-WECs under the proper operational strategy. This study undertakes an exhaustive analysis of geometric parameters, encompassing turbine diameter, blade number, and thickness. An experiment-validated numerical model based on the unsteady two-phase Reynolds-averaged Navier–Stokes equations is adopted in the research. Comprehensive investigations include analyses of flow fields around the turbine, pressure distributions on blade surfaces, and dynamic torque variations. These analyses serve to elucidate the variation rules of hydrodynamic characteristics and their influential mechanisms. The results highlight the notable impact of the proposed "relative-short wavelength impact" on the performance of SHT-WECs operating under IPLS conditions. Notably, no significant impact is observed when the relative wavelength exceeds 17. Optimal performance is achieved with the thinnest and two-bladed turbine configuration. Moreover, optimizing the turbine diameter significantly enhances SHT-WEC conversion efficiency, with the attained maximum value reaching approximately 18.6%. This study offers a concise guideline for designing turbine diameters in alignment with specific wave conditions. [ABSTRACT FROM AUTHOR]

Generating questions from the long passage is an important and challenging task. Most of the recent works focus on generating questions whose answers are consecutive text spans in the given passage. However, realistic questions are more complicated and their answers are always inductive and summative. In this paper, we focus on a complex form of question generation task, in which the answer is implied in the long passage. It means that we cannot directly find sentences relevant to the question in the passage anymore. To this end, we first construct a dataset that meets our needs on top of RACE. Based on this, we propose an Intent-aware Complex Question Generation model (ICQG). It first encodes the long passage, which exploits a gated mechanism to fetch the valuable information for elaborating the question. And then, both the passage and answer are used to support the question decoding by modeling their interaction. Finally, an intent classifier is designed to predict what kinds of questions tend to be asked, which is used to guide the question decoding. We conduct both qualitative and quantitative evaluations, and the experimental results demonstrate that the proposed model is effective on this task and superior to the competitor methods. [ABSTRACT FROM AUTHOR]

In order to improve the effect of diversified visual communication, this paper combines computer digital technology to design a multidimensional visual communication system. In order to improve lighting performance, parts of the surface of the secondary processing visually conveyed image have been processed with different diffusing materials, and the effects have been compared in simulations. There are two types of simulations: external simulation and internal simulation. Moreover, the cutting method based on the shape of the lighting area can design a rectangular lighting area, and the diffusing material can improve the lighting performance to a certain extent. In addition to this, according to the shape of the set target plane, a cut visual communication image is obtained. Through multiple simulation experiments, this paper verifies that the diversified visual communication design system based on computer digital technology can effectively improve the visual communication effect. [ABSTRACT FROM AUTHOR]

Roller clinching is a variation of conventional clinching by using rotational tool movement. The joining quality of roller clinching is significantly affected by tooling geometries and motions. Considering the formation difference of joints at different locations, this paper investigated the deformation features of roller clinching of square joints and utilized multiple linear regression analysis to optimize the processing parameters. It was found that roller geometry has significant impact on the formation of interlocks of the front/rear sides of joints, while the impact on the formation of lateral sides is less. With the increase of roller diameters, the clearance variation of front/rear sides decreases; meanwhile, the separation clearance s at the front side after forming decreases. In the study, when the roller diameter is raised from 35 to 150 mm, the connection strength increases by 44%. If the diameter difference w of rollers increases, the squeezing degree of the front side decreases, and the joining quality increases; however, if the squeezing degree of the rear side increases, then the joining quality of the rear side and s decrease. In the sample, an increase in w by 3 mm enhanced the connection strength by 9%. When the clearance difference t between the rollers increases, the capability to contain metal increases in the rear side. When t increases by 0.6 mm, the connection strength augments by 12%. The separation clearance s of the front side is greatly affected by friction μ, roller diameter, w, and draft angle γ of the lower roller, while the effect of draft angle β of the upper roller on s is small. [ABSTRACT FROM AUTHOR]