169 research outputs found
Optimization of Superplastic Forming Process of AA7075 Alloy for the Best Wall Thickness Distribution
This work aims to optimize the process parameters for improving the wall thickness distribution of the sheet superplastic forming process of AA7075 alloy. The considered factors include forming pressure p (MPa), deformation temperature T (°C), and forming time t (minutes), while the responses are the thinning degree of the wall thickness ε (%) and the relative height of the product h*. First, a series of experiments are conducted in conjunction with response surface method (RSM) to render the relationship between inputs and outputs. Subsequently, an analysis of variance (ANOVA) is conducted to verify the response significance and parameter effects. Finally, a numerical optimization algorithm is used to determine the best forming conditions. The results indicate that the thinning degree of 13.121% is achieved at the forming pressure of 0.7 MPa, the deformation temperature of 500°C, and the forming time of 31 minutes
Language-driven Scene Synthesis using Multi-conditional Diffusion Model
Scene synthesis is a challenging problem with several industrial
applications. Recently, substantial efforts have been directed to synthesize
the scene using human motions, room layouts, or spatial graphs as the input.
However, few studies have addressed this problem from multiple modalities,
especially combining text prompts. In this paper, we propose a language-driven
scene synthesis task, which is a new task that integrates text prompts, human
motion, and existing objects for scene synthesis. Unlike other single-condition
synthesis tasks, our problem involves multiple conditions and requires a
strategy for processing and encoding them into a unified space. To address the
challenge, we present a multi-conditional diffusion model, which differs from
the implicit unification approach of other diffusion literature by explicitly
predicting the guiding points for the original data distribution. We
demonstrate that our approach is theoretically supportive. The intensive
experiment results illustrate that our method outperforms state-of-the-art
benchmarks and enables natural scene editing applications. The source code and
dataset can be accessed at https://lang-scene-synth.github.io/.Comment: Accepted to NeurIPS 202
Effects of dietary tryptophan on cannibalism, survival and growth of Wallago attu (Bloch & Schneider, 1801) juveniles
This study aims to evaluate the effects of supplemented commercial diets with tryptophan (TRP) on plasma serotonin, cannibalism, survival rate, and growth of Wallago attu (helicopter catfish). After one week of acclimation, 3,200 juveniles of helicopter catfish (BW = 2.5 ± 0.27 g, total length = 5.6 ± 0.43 cm) were randomly assigned for the experiment in fifteen plastic tanks (200 L). The experiment was conducted with five treatments (CT – 0 g TRP/kg – control group, T1 – 5 g TRP/kg, T2 – 10 g TRP/kg, T3 – 20 g TRP/kg, and T4 – 40 g TRP/kg) in a completely randomized design with three replications for four weeks. The results from the enzyme-linked immunosorbent assay reveal that TRP-supplemented diets effectively increased the serotonin level (5-HT) in the plasma of the catfish. The serotonin level increased with the dose of TRP added to the feed. Furthermore, a higher TRP level significantly decreased cannibalism and improved the final survival of the fish. However, the fish’s growth rate among treatments T1, T2, T3, and T4 was not significantly different, but there was a statistical difference between the experimental treatments and the CT treatment. The findings of this study suggest that TRP could be supplemented at a dose of 20 g·kg–1 to the feed to reduce cannibalism and improve the final survival of helicopter catfish
Slip Resistance Test Apparatus of Synthetic Rubber Trackpad on Photovoltaic Surface
The increasing development of the solar energy industry in many countries has
led to a rising frequency of human and robot presence in this area. To ensure
occupational safety, various protective equipment, including rubber material,
is commonly used for slip resistance while moving on the surface of solar PV
panels. Therefore, the slip resistance test apparatus is built for testing the
slip resistance between the synthetic rubber trackpad and the photovoltaic
panel (PV) surface. Synthetic rubber is a man-made material, so it is difficult
to control the parameters of its mechanical and chemical properties absolutely.
Variations in wet/dry working conditions or Shore hardness are factors that
make slip computation more challenging. Therefore, an apparatus with the
principle of converting the reciprocating motion of the screw and the casters
into the rotation of the hinge is introduced to adjust the tilt angle of the
upper surface, detect and evaluate the slippage of the rubber trackpad by
sensors. Some parameters related to accuracy such as vibration and
theoretical-empirical assessment, are also mentioned. In addition to designing
a reliable apparatus, the article also succeeded in providing a safety standard
for synthetic rubber with Shore A30-A40 when moving on PV surfaces.Comment: 4 pages, 10 figures, The 20th International Conference on Ubiquitous
Robots (UR 2023
MORPHOLOGICAL AWARENESS OF STUDENTS MAJORING IN ENGLISH STUDIES TOWARDS VOCABULARY LEARNING
For those learning a second language, vocabulary plays a vital role in mastering the new one, and possessing a colossal vocabulary is extremely necessary. The paper aims to look into and assess students' awareness of morphology and the effectiveness of this approach through vocabulary learning. The subjects in this study were juniors majoring in English at a university in the south of Vietnam. The test, questionnaire, and interview were the three instruments used in this study to triangulate the results. A total of 49 students majoring in English Studies took the test, 40 students completed the questionnaire, and four students participated in an interview to evaluate their proficiency and morphological knowledge. The results of the study showed that students' awareness levels were average, and they were knowledgeable enough to employ this strategy for acquiring vocabulary. Additionally, it also enables students to comprehend morphology's benefits and drawbacks during their learning vocabulary process. Article visualizations
ADSORPTION OF Hg (II) FROM AQUEOUS SOLUTION USING CARBOXYMETHYL GLUCOMANNAN DERIVATIVE
Carboxymethyl glucomannan derivative (CMG) with the degree of substitution of 0.697 was synthesized from the reaction of monochloroacetic acid (MCA) with glucomannan paeoniiifolius (GP) at 60 C, pH10 for 3 h. Its structural characteristics were proven by nuclear magnetic resonance (NMR). The resulting derivative was used to adsorb Hg2+ ion from aqueous solutions. The effects of pH, initial concentration of metal ions and contact time on CMG’s adsorption behaviors were also investigated. The results have shown that the optimal pH for adsorption was about 6.5; the adsorption capacity rapidly reached equilibrium within 40 minutes; the maximum adsorption capacity of CMG for Hg2+ ion was 615 mg/g
NUMERICAL SIMULATION TO STUDY EFFECT OF DIE DESIGN PARAMETERS ON DEFORMATION POSSIBILITY OF METAL ON COMBINED DRAWING
This paper uses numerical simulation to study amethod in combined drawing process with thinning the wall when drawing of a cylindrical cup of sheet metal. The software Deform 2D is used to examineeffect of die design parameters (inclination of die) on deformation possibility of metal. Simulation results in order to select appropriate die design parameters (conical die), to enhance the ability to deform and contribute to improve product quality
THE TRANSFER MATRIX METHOD FOR MODAL ANALYSIS OF CRACKED MULTISTEP BEAM
The present study addresses the modal analysis of multistep beam with arbitrary number of cracks by using the transfer matrix method and modal testing technique. First, there is conducted general solution of free vibration problem for uniform beam element with arbitrary number of cracks that allows one to simplify the transfer matrix for cracked multistep beam. The transferring beam state needs to undertake only at the steps of beam but not through crack positions. Such simplified the transfer matrix method makes straightforward to investigate effect of cracks mutually with cross-section step in beam on natural frequencies. It is revealed that step-down and step-up in beam could modify notably sensitivity of natural frequencies to crack so that the analysis provides useful indication for crack detection in multistep beam. The proposed theory was validated by an experimental case stud
MODAL ANALYSIS OF MULTISTEP TIMOSHENKO BEAM WITH A NUMBER OF CRACKS
Modal analysis of cracked multistep Timoshenko beam is accomplished by the Transfer Matrix Method (TMM) based on a closed-form solution for Timoshenko uniform beam element. Using the solution allows significantly simplifying application of the conventional TMM for multistep beam with multiple cracks. Such simplified transfer matrix method is employed for investigating effect of beam slenderness and stepped change in cross section on sensitivity of natural frequencies to cracks. It is demonstrated that the transfer matrix method based on the Timoshenko beam theory is usefully applicable for beam of arbitrary slenderness while the Euler-Bernoulli beam theory is appropriate only for slender one. Moreover, stepwise change in cross-section leads to a jump in natural frequency variation due to crack at the steps. Both the theoretical development and numerical computation accomplished for the cracked multistep beam have been validated by an experimental stud
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