Multimodal Recommendation Dialog with Subjective Preference: A New Challenge and Benchmark

Existing multimodal task-oriented dialog data fails to demonstrate the diverse expressions of user subjective preferences and recommendation acts in the real-life shopping scenario. This paper introduces a new dataset SURE (Multimodal Recommendation Dialog with SUbjective PREference), which contains 12K shopping dialogs in complex store scenes. The data is built in two phases with human annotations to ensure quality and diversity. SURE is well-annotated with subjective preferences and recommendation acts proposed by sales experts. A comprehensive analysis is given to reveal the distinguishing features of SURE. Three benchmark tasks are then proposed on the data to evaluate the capability of multimodal recommendation agents. Based on the SURE, we propose a baseline model, powered by a state-of-the-art multimodal model, for these tasks.Comment: ACL 202

Direct Lithium Extraction from α-Spodumene through Solid-State Reactions for Sustainable Li2CO3 Production.

With increasing battery demand comes a need for diversified Li sources beyond brines. Among all Li-bearing minerals, spodumene is most often used for its high Li content and natural abundance. However, the traditional approach to process spodumene is costly and energy-intensive, requiring the mineral be transformed from its natural α to β phase at >1000 °C. Acid leaching is then applied, followed by neutralization to precipitate Li2CO3. In this work, we report an alternative method to extract Li directly from α-spodumene, which is performed at lower temperatures and avoids the use of acids. It is shown that Li2CO3 is formed with >90% yield at 750 °C by reacting α-spodumene with Na2CO3 and Al2O3. The addition of Al2O3 is critical to reduce the amount of Li2SiO3 that forms when only Na2CO3 is used, instead providing increased thermodynamic driving force to form NaAlSiO4 and Li2CO3 as the sole products. We find that this reaction is most effective at 4 h, after which volatility limits the yield. Following its extraction, Li2CO3 can be isolated by washing the sample using deionized water. This energy-saving and acid-free route to obtain Li2CO3 directly from spodumene can help meet the growing demand for Li

Effects of Impeller Diameter on High-Speed Rescue Pump

Impeller diameter is a crucial design parameter of high-speed rescue pumps because it affects the performance and inner flow characteristics of these pumps. In this study, a pump with an impeller diameter of 248 mm was modeled and its performance was tested. Numerical simulations were conducted under steady and unsteady states, in which the sizes of the impeller diameters were designated as 248 mm (original), 235.6 mm (5% trimmed), 223.2 mm (10% trimmed), and 210.8 mm (15% trimmed). ANSYS software was used to test the shear stress transport (SST k-ω) of the four models, and results agreed well with experimental data. Diameter size affected impeller characteristics in both steady and unsteady states. Subsequently, the differences in performance, hydraulic loss, pressure pulsation, and radial force of the impellers were evaluated. In the performance test, the head and efficiency of the pump decreased as impeller diameter was reduced. The result trends are in accordance with the trim law within the acceptable error range. In terms of hydraulic loss, the impeller and diffuser vane components presented opposite trends with flow rate increase. Finally, in terms of pressure pulsation and radial force, the amplitude diminished while periodicity improved as impeller diameter decreased

VDialogUE: A Unified Evaluation Benchmark for Visually-grounded Dialogue

Visually-grounded dialog systems, which integrate multiple modes of communication such as text and visual inputs, have become an increasingly popular area of investigation. However, the absence of a standardized evaluation framework poses a challenge in assessing the development of this field. To this end, we propose \textbf{VDialogUE}, a \textbf{V}isually-grounded \textbf{Dialog}ue benchmark for \textbf{U}nified \textbf{E}valuation. It defines five core multi-modal dialogue tasks and covers six datasets. Furthermore, in order to provide a comprehensive assessment of the model's performance across all tasks, we developed a novel evaluation metric called VDscore, which is based on the Analytic Hierarchy Process~(AHP) method. Additionally, we present a straightforward yet efficient baseline model, named \textbf{VISIT}~(\textbf{VIS}ually-grounded d\textbf{I}alog \textbf{T}ransformer), to promote the advancement of general multi-modal dialogue systems. It progressively builds its multi-modal foundation and dialogue capability via a two-stage pre-training strategy. We believe that the VDialogUE benchmark, along with the evaluation scripts and our baseline models, will accelerate the development of visually-grounded dialog systems and lead to the development of more sophisticated and effective pre-trained models

Second-harmonic generation with broadened flattop bandwidth in aperiodic domain-inverted gratings

Abstract We report on a theoretical analysis for the broadened bandwidth of the fundamental waves in aperiodic gratings. The sequences and the length of the domains are optimized to realize the pre-designed wide bandwidth in the quasiphase-matched (QPM) second-harmonic generation (SHG) by the simulated annealing (SA) method. About 3 nm prescribed flattop bandwidth as the full width at 95% maximum with 25% reduction of the nonlinear coefficient relative to that of a perfectly periodic QPM grating are obtained. Domains overgrown owing to the room-temperature electric poling technique show little influence on the broad bandwidth of the fundamental waves. Ó 2002 Published by Elsevier Science B.V

Texture Detection of Aluminum Foil Based on Top-Hat Transformation and Connected Region Segmentation

A new method of texture detection for aluminum foil based on digital image processing technology is proposed. Top-hat transformation and image segmentation technology based on the connected domain are used to change the method of determining texture fraction by using human experience. Compared with the brightness method, pit detection method, and EBSD technology, this method can complete quantitative detection efficiently, automatically, and accurately, and reduce the detection time and manpower. It eliminates the instability of manual detection and ensures the accuracy of detection. By this method, the error of test results can be controlled within 1.6%, which is much better than 7.3% of the brightness method and 4% of the pitting method. It provides more accurate test results for the production process control of aluminum foil

Optimization Design of the Impeller Based on Orthogonal Test in an Ultra-Low Specific Speed Magnetic Drive Pump

To improve the hydraulic performance in an ultra-low specific speed magnetic drive pump, optimized design of impeller based on orthogonal test was carried out. Blades number Z, bias angle in peripheral direction of splitter blades θs, inlet diameter of splitter blades Dsi, and deflection angle of splitter blades α were selected as the main factors in orthogonal test. The credibility of the numerical simulation was verified by prototype experiments. Two optimized impellers were designed through the analysis of orthogonal test data. The internal flow field, pressure fluctuation, and radial force were analyzed and compared between optimized impellers and original impeller. The results reveal that impeller 7 (Z = 5, θs = 0.4θ, Dsi = 0.75D2, α = 0°) could increase the head and efficiency, compared to the original impeller, by 2.68% and 4.82%, respectively. Impeller 10 (Z = 5, θs = 0.4θ, Dsi = 0.55D2, α = 0°) reduced the head by 0.33% and increased the efficiency by 8.24%. At design flow rate condition, the internal flow of impeller 10 was the most stable. Peak-to-peak values of pressure fluctuation at the volute tongues of impeller 7 and impeller 10 were smaller than those of the original impeller at different flow rate conditions (0.6 Qd, 1.0 Qd and 1.5 Qd). Radial force distribution of impeller 10 was the most uniform, and the radial force variance of impeller 10 was the smallest

Experiments and Numerical Simulation of Performances and Internal Flow for High-Speed Rescue Pump with Variable Speeds

The model pump is a high-speed, high-power pump designed to achieve rapid mine flooding rescue. This study conducted experiments to investigate pump performance curves, including head, efficiency, and power for the following six different rotation speeds: 3000, 3600, 4200, 4800, 5400, and 6000 rpm. Then, the numerical simulation method based on computational fluid dynamics commercial code Ansys was used to present the internal flow of the pump for the six different rotation speeds through steady and unsteady analyses. Results show that the numerical results agree well with experimental data. The designs of outlet and inlet angles of the impeller match each other well at high rotation speeds. The pressure pulsation coefficient Cp in the impeller and the diffuser channel remain constant at the same monitor point under different rotation speed conditions. The varying trend of the pressure-augmented coefficient ΔP indicates that, with the increase in rotation speed, the effect on pressure rise induced by the back part of the impeller channel is more evident than that by the front part. Also, the main frequency components of ΔP are concentrated on the region with low frequency. Moreover, the rotation speed has no significant effect on ΔP in the diffuser region. This study provides effective guidance and valuable reference for the design of high-speed, high-power pumps

Optimization strategy of switching modulation of mine—used high—voltage frequency converter

For problems of high switching loss and power quality distortion when carrier modulation PWM control method were used in mine—used high—voltage frequency converter. Sinusoidal modulation wave was optimized based on carrier—in—phase disposition PWM control method. The sinusoidal modulation wave is superimposing with the third harmonic and direct current component, so as to obtain an optimized modulation wave with saddle—shaped modulation wave in positive half—cycle and trapezoidal modulation wave in negative half—cycle. The simulation results show that DC voltage utilization of frequency converter is improved, switching loss and total harmonic distortion of output line voltage is reduced by use of the optimized modulation wave