Search

Your search keyword '"Fan, Yuchao"' showing total 199 results
Start Over Author "Fan, Yuchao"
199 results on '"Fan, Yuchao"'

1. Dissecting the dot-com bubble in the 1990s NASDAQ

Author

Fan, Yuchao

Subjects
Economics - General Economics
Abstract

In this paper, I revisit Phillips, Wu and Yu's seminal 2011 paper on testing for the dot-com bubble. I apply recent advancements of their methods to individual Nasdaq stocks and use a novel specification for fundamentals. To address a divide in the literature, I generate a detailed sectoral breakdown of the dot-com bubble. I find that it comprised multiple overlapping episodes of exuberance and that there were indeed two starting dates for internet exuberance.

Published
2022

23. Predictive modeling of rice milling degree for three typical Chinese rice varieties using interpretative machine learning methods.

Author

Yang, Liu, Xu, Zilong, Xiao, Xuan, Cui, Bo, Luo, Yang, Fan, Lanlan, Fan, Yuchao, Song, Shaoyun, Zhang, Yonglin, and Pei, Houchang

Subjects
RICE milling, DEEP learning, RICE, RICE processing, MACHINE learning
Abstract

Brown rice over‐milling causes high economic and nutrient loss. The rice degree of milling (DOM) detection and prediction remain a challenge for moderate processing. In this study, a self‐established grain image acquisition platform was built. Degree of bran layer remaining (DOR) datasets is established with image capturing and processing (grain color, texture, and shape features extraction). The mapping relationship between DOR and the DOM is in‐depth analyzed. Rice grain DOR typical machine learning and deep learning prediction models are established. The results indicate that the optimized Catboost model can be established with cross‐validation and grid search method, with the best accuracy improving from 84.28% to 91.24%, achieving precision 91.31%, recall 90.89%, and F1‐score 91.07%. Shapley additive explanations analysis indicates that color, texture, and shape feature affect Catboost prediction accuracy, the feature importance: color > texture > shape. The YCbCr‐Cb_ske and GLCM‐Contrast features make the most significant contribution to rice milling quality prediction. The feature importance provides theoretical and practical guidance for grain DOM prediction model. Practical Application: Rice milling degree prediction and detection are valuable for rice milling process in practical application. In this paper, image processing and machine learning methods provide an automated, nondestructive, and cost‐effective way to predict the quality of rice. The study may serve as a valuable reference for improving rice milling methods, retaining rice nutrition, and reducing broken rice yield. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

39. Research on microstructural‐mechanical and shearing properties of castor seed during mechanical extraction.

Author

Yang, Liu, Cui, Bo, Chen, Huan, Fan, Yuchao, Zhang, Yonglin, Song, Shaoyun, Yin, Qiang, Zhao, Gang, and Hao, Zhiqiang

Subjects
CASTOR oil, OILSEEDS, SEEDS, SCANNING electron microscopy, OPTICAL microscopes, ENDOSPERM, SCREWS, TRIBO-corrosion
Abstract

Castor seed oil, as an important biomass fuel, has attracted extensive attention worldwide due to inclusive applications. Castor seed screw mechanical extraction is in fact seed shear damage and oil output. Seed shearing mechanism has been investigated with a developed tribometer. Influences of pressing load, shearing speed, roller roughness were analyzed. Castor seed structural damage was in‐situ observed with optical microscope, and in‐depth analyzed with Scanning Electron Microscopy and Energy Dispersive Spectroscopy. The results reveal that shear interaction can be divided into three stages: coat damage, transition shearing and endosperm oil output. Seed shear mechanism includes coat peeling, endosperm plowing, tissue transferring and oil lubrication. High pressing load leads to more damage of coat and endosperm, causing more oil to flow out. With shearing speed increasing, coat is easily peeled, obvious endosperm shear plowing and oil lubrication happened in contact area. Coat damage by high roughness leads more oil output. Castor oil enters the contact area and work as lubricant, leading to the decrease of friction resistance. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

40. Tailoring Ti3C2TxMXene Flake Sizes for Modified Electrochemical Performance: A Top-down Approach

Author

Fan, Yuchao, Mei, Xu, Ye, Li, Tian, Qingyong, Zhang, Renqi, Zhang, Yingjiu, and Li, Xinjian

Abstract

Introduction: Two-dimensional (2D) materials, such as MXene (Ti3C2Tx), have garnered extensive attention in recent years due to their exceptional performance across various domains. The flake size of Ti3C2Txnotably influences its specific surface area, a pivotal factor in interfacial interactions within electrochemistry.Method: Presently, modifying the flake size of bulk Ti3C2Txtypically involves complex and costly processes, like ultrasonic treatment and isolation. Leveraging the specific preparation principle of MXenes, which involves etching the A layers in precursor MAX phases, a topdown strategy for producing Ti3C2Txflakes of desired sizes, has been proposed in this work. In this approach, precursor Ti3AlC2 particles undergo ball-milling to adjust their size.Result: Through this innovative strategy, dispersions of Ti3C2Txflakes with varying average lateral sizes are generated, enabling an investigation into the impact of lateral size on the electrochemical properties of Ti3C2Txflakes. By controlling the ball milling time for Ti3AlC2powders, the resulting average sizes of Ti3C2Tx(0, 2, 4) are 6.34 µm, 2.16 µm, and 0.96 µm, respectively. Particularly, the Ti3C2Tx(2) electrode, composed of 2.16 µm sheets, demonstrates remarkable performance metrics. It exhibits a high areal capacitance of 845.0 mF/cm2at a scan rate of 5 mV/s, along with a gravimetric capacitance of 244.0 F/g at a current density of 1 A/g.Conclusion: This study presents a facile method to enable mass production of Ti3C2Txwith sheets of varying sizes, addressing both small and large dimensions.

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results