Magnetically separable attapulgite−TiO2−FexOy composites with superior activity towards photodegradation of methyl orange under visible light radiation

Jiahui Zhang,Lili Zhang,Shouyong Zhou,Haiqun Chen,Hui Zhong,Yijiang Zhao,Xin Wang 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.5

A magnetically recoverable composite photocatalyst was obtained by introducing TiO2–FexOy hybrid oxide onto the surface of attapulgite via an in-situ deposit technique (marked as ATT–TiO2–FexOy-r, r represents molar ratio of r = nTi/(nTi + nFe)). The obtained composites were carefully characterized and results showed TiO2–FexOy particles with an average size of 10 nm were successfully loaded onto attapulgite fibers’ surface. The FexOy (mixture of Fe2O3 and Fe3O4) acted not only as magnetic source but also took part in the formation of TiO2–Fe2O3 heterojunction structure, which resulted in the obvious absorption in visible light region for the obtained ATT–TiO2–FexOy. The obtained ATT–TiO2–FexOy-r exhibited quite good catalytic activity towards photodegradation of methyl orange under visible light irradiation. The highest degradation ratio and COD removal of methyl orange reached to 94.13% and 90.91% for ATT–TiO2–FexOy-0.5. Moreover, ATT–TiO2–FexOy could be readily recovered and the degradation ratio maintains 83.89% after 5 cycles. Possible mechanism for this enhancement was proposed.

Crimes Committed by Legal Persons: A Comparative Sino-German perspective

Jiahui Shi 이준국제법연구원 2019 China and WTO Review Vol.5 No.1

PLI-VIO: Real-time Monocular Visual-inertial Odometry Using Point and Line Interrelated Features

Jiahui Zhang,Qingzhen Shang,Jinfu Yang,Mingai Li 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.6

As a popular technology, visual-inertial odometry (VIO) has been widely applied in many fields such as autonomous robots and unmanned aerial vehicle (UAV). However, the trade-off between localization accuracy and real-time performance still needs to be optimized. This paper presents a real-time tightly-coupled monocular VIO system using point and line interrelated features (PLI-VIO) under the sliding window optimization framework. In line feature extraction part of PLI-VIO, a line segment extraction and coalescence algorithm based on EDlines is proposed, which extracts line features in real-time without concession on feature quality. At the same time, in order to get efficient and robust line tracking effect, PLI-VIO presents a line-to-point tracking method that fully utilizes the interrelation between point and line. Specifically, line features are divided as a group of points and tracked by pyramidal implementation of Lucas Kanade feature tracker. The proposed line feature tracking method can effectively reduce time consumption on tracking process in a robust way. Extensive evaluations on Euroc and TUM-VI public datasets are performed to demonstrate the preferable performance of our proposed system, and the results show that PLI-VIO obtains better localization accuracy with less computation cost compared against other state-of-the-art VIO algorithms.

Twin Deterministic Policy Gradient Adaptive Dynamic Programming for Optimal Control of Affine Nonlinear Discrete-time Systems

Jiahui Xu,Jingcheng Wang,Jun Rao,Yanjiu Zhong,Shangwei Zhao 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.9

Recent achievements in the field of adaptive dynamic programming (ADP), as well as the data resources and computational capabilities in modern control systems, have led to a growing interest in learning and data-driven control technologies. This paper proposes a twin deterministic policy gradient adaptive dynamic programming (TDPGADP) algorithm to solve the optimal control problem for a discrete-time affine nonlinear system in a modelfree scenario. To solve the overestimation problem resulted from function approximation errors, the minimum value between the double Q network is taken to update the control policy. The convergence of the proposed algorithm in which the value function is served as the Lyapunov function is verified. By designing a twin actor-critic network structure, combining the target network and a specially designed adaptive experience replay mechanism, the algorithm is convenient to implement and the sample efficiency of the learning process can be improved. Two simulation examples are conducted to verify the efficacy of the proposed method.

Stochastic Disturbance Propagation Model Analysis of Power Grids Based on Epidemic Model and Improved Clustering

Jiahui Jin,Yonghui Liu 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.12

Based on epidemic model, a stochastic disturbance propagation model of power grids is proposed in this paper. Firstly, compared with epidemic model, some concepts in power grids are introduced. Then, by analyzing parameters of the nodes, some key nodes are extracted. Hence, the complex power grids are divided into some simple power grids. For the simple power grids, taking Markovian chain into account, the probability of the propagation is solved backward. Combined with the probability and the parameters of the power grids, a model describing importance of the nodes is established. Finally, to demonstrate the effectiveness of the model, an improved clustering algorithm is proposed. The simulation results show that the model has high accuracy in selecting the key nodes. Moreover, it provides an effective method in prediction of power grids.

Numerical Simulation of Acoustic Structure Interaction using Spectral Difference with Dynamics Grid

Jiahui Han,Junhui Gao 한국전산유체공학회 2022 한국전산유체공학회 학술대회논문집 Vol.2022 No.10

HS-Sign: A Security Enhanced UOV Signature Scheme Based on Hyper-Sphere

( Jiahui Chen ),( Shaohua Tang ),( Xinglin Zhang ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.6

For “generic” multivariate public key cryptography (MPKC) systems, experts believe that the Unbalanced Oil-Vinegar (UOV) scheme is a feasible signature scheme with good efficiency and acceptable security. In this paper, we address two problems that are to find inversion solution of quadratic multivariate equations and find another structure with some random Oil-Oil terms for UOV, then propose a novel signature scheme based on hyper-sphere (HS-Sign for short) which directly answers these two problems. HS-Sign is characterized by its adding Oil-Oil terms and more advantages compared to UOV. On the one side, HS-Sign is based on a new inversion algorithm from hyper-sphere over finite field, and is shown to be a more secure UOV-like scheme. More precisely, according to the security analysis, HS-Sign achieves higher security level, so that it has larger security parameters choice ranges. On the other side, HS-Sign is beneficial from both the key side and computing complexity under the same security level compared to many baseline schemes. To further support our view, we have implemented 5 different attack experiments for the security analysis and we make comparison of our new scheme and the baseline schemes with simulation programs so as to show the efficiencies. The results show that HS-Sign has exponential attack complexity and HS-Sign is competitive with other signature schemes in terms of the length of the message, length of the signature, size of the public key, size of the secret key, signing time and verification time.

On the Performance Limits of Cryogenically Operated SiGe HBTs and Its Relation to Scaling for Terahertz Speeds

Jiahui Yuan,Cressler, J.D.,Krithivasan, R.,Thrivikraman, T.,Khater, M.H.,Ahlgren, D.C.,Joseph, A.J.,Jae-Sung Rieh IEEE 2009 IEEE transactions on electron devices Vol.56 No.5

<P>The goal of achieving terahertz (THz) transistors within the silicon material system has generated significant recent interest. In this paper, we use operating temperature as an effective way of gaining a better understanding of the performance limits of SiGe HBTs and their ultimate capabilities for achieving THz speeds. Different approaches for vertical profile scaling and reduction of parasitics are addressed, and three prototype fourth-generation SiGe HBTs are compared and evaluated down to deep cryogenic temperatures, using both dc and ac measurements. A record peak f<SUB>T</SUB>/f<SUB>max</SUB> of 463/618 GHz was achieved at 4.5 K using 130-nm lithography (309/343 GHz at 300 K), demonstrating the feasibility of reaching half-THz f<SUB>T</SUB> and f<SUB>max</SUB> simultaneously in a silicon-based transistor. The BV<SUB>CEO</SUB> of this cooled SiGe HBT was 1.6 V at 4.5 K (BV<SUB>CBO</SUB> = 5.6 V), yielding a record f<SUB>T</SUB> times BV<SUB>CEO</SUB> product of 750 GHzldrV (510 GHzldrV at 300 K). These remarkable levels of transistor performance and the associated interesting device physics observed at cryogenic temperatures in these devices provide important insights into further device scaling for THz speeds at room temperature. It is predicted in a new scaling roadmap that f<SUB>T</SUB>/f<SUB>max</SUB> of room-temperature SiGe HBTs could potentially achieve 782/910 GHz at a BV<SUB>CEO</SUB> of 1.1 V at the 32-nm lithographic node.</P>

Perceived Authenticity through Short Video: Audience Perceptions of Emerging Independent Fashion Designers Self-Presentations

JIAHUI YAO,SEHWA KIM 한국콘텐츠학회 2021 International Journal of Contents Vol.17 No.4

The prevalence of We-Media short videos has attracted emerging independent fashion designers (EIFD), a new force in the fashion industry directing their brand promotion to We-Media for amassing online followers. However, compared to famous content generators, EIFDs creative, design-based visual appeal has not provided them with the significant edge. The former’s success is admittedly supported by the platform backstage algorithm. Yet, the content is the cornerstone for building relationship between the sender and the reception. The authentic perception of the content is one of the basic appeals for which the audience chooses to follow the source. Therefore, with the EIFD short video as the research content, this study is established from the audiences perspective to understand the different dimensions of their authentic perceptions of EIFDs short video. The study was conducted mainly in the form of the Q method. The collection of 52 Q samples were realized through the Focus Group Interview and literature review on multidimensional authenticity. Thirty-six subjects participated in the sorting of the Q-sets. Finally, four dimensions of audience authenticity perceptions of EIFDs were derived: ‘ingenuity’, ‘relevant’, ‘transparent’, and ‘experiential’. The corresponding short video content design strategies are suggested for effective communication of EIFDs and their personal brands.

论“南行”时期苏轼的山水诗心

JIAHUI LI,崔秢僔 전북대학교 인문학연구소 2024 건지인문학 Vol.- No.39

This paper mainly focuses on the aesthetic pattern of Su Shi's landscape poetry during the period of "Southbound Collection" by the father and sons of the "Three Sus", and systematically examines Su Shi's family background, early growth experience, and literary creation ideas in his youth. According to the "Southward Journey", the core ideas of Su Shi's early landscape poems, as well as the author's creative ideas and literary propositions are discussed. In addition to the expression of Confucianism, Su Shi's landscape poems during his journey to the south also contain the poet's thoughts on the universe and time. In Su Shi's poems, although he often revealed the tragic consciousness of the fleeting nature of time, he also immediately dispelled the tragic consciousness with the ideals and aspirations of scholars, showing the poet's open-mindedness. His occasional contemplation of life in his poems also laid the ideological foundation for Su Shi's later devotion to Buddhism and Zen. This paper intends to use the two clues of "the beauty of mountains and rivers" and "the relics of the ancestors" to deeply study Su Shi's creative style and aesthetic care during the southward period. Su Shi's poems during his travels weremainly reflected in his thoughts on the finite time and the eternity of the universe, and the contradiction between being an official and a hermit. These thoughts and expressions reflected Su Shi's unique understanding and knowledge of life, and have had a profound impact on Chinese literature. The exploration of Su Shi's early thought is also of certain value for studying the changes in his thinking and literary style after he was repeatedly degraded. 本文主要探究“三苏”父子“南行”时期苏轼的山水诗审美格局,系统地考察了苏轼的家庭背景、早期成长经历和青年时期的文学创作思想。根据《南行集》探讨了苏轼早期山水诗的核心思想,以及诗人的创作理念和文学主张。除了儒家思想的表达,苏轼南行期间的山水诗也饱含了诗人许多关于宇宙和时间的思考。在苏轼的诗词中,诗人虽时常流露出对时间转瞬即逝的悲剧意识,但也立刻用士人的理想抱负消解悲剧意识,体现了无限豁达的胸怀。其偶尔在诗歌中流露出对生活的沉思,也为苏轼屡遭贬谪后投身于佛禅奠定了思想基础。本文拟通过“山川之秀美”和“先君子之遗迹”两条线索,深入探究苏轼在南行时期的创作风格和审美关怀。苏轼在宦游之中所作的山水诗主要体现了他对有限的时间与宇宙永恒的思考、为官与隐士的矛盾思想等。这些思想和表达反映了苏轼对生活的独特见解和认识,对中国文学的发展产生了深远的影响。本文对苏轼早期思想的探究对今后研究苏轼屡遭贬谪后思想及文风的变化亦有一定的价值。