Construction and Analysis of Inter-couplings for the Structural Controllability of Interdependent Networks

Tianjiao Guo,Lang Chai,Yifei Guo,Lilan Tu 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.7

In this paper, we construct the inter-couplings and analyze the structural controllability of interdependent networks with known directed subnets. Firstly, we divide the interdependent network into a leader-system and a follower-system. The leader-system is proved to be certainly controllable, so we focus on constructing intercouplings between two follower-subsystems and analyzing the structural controllability of the follower-system when the positions and the number of the leaders are fixed. Secondly, based on Kalman rank criterion, PBH rank criterion, as well as the graph maximum matching algorithm, combined with the controllable structure decomposition algorithm, several sufficient or necessary conditions for the structural controllability of the topological isomorphic follower-system are proposed to guarantee whether the follower-system and interdependent network are controllable or not. All the conditions provided in this paper also are suitable for the networks with undirected subnets. Finally, we take two examples to illustrate the feasibility and effectiveness of our theoretical conclusions.

Hydraulic and Mechanical Coupling Analysis of Rough Fracture Network under Normal Stress and Shear Stress

Tianjiao Yang,Shuhong Wang,Pengyu Wang,Ze Zhang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.2

The hydraulic and mechanical coupling characteristics of fracture networks under normal stress and shear stress were studied in this paper. The hydraulic and mechanical coupling model of the fracture network comprehensively considers the normal stress, shear stress, seepage pressure and roughness characteristics. Based on the boundary conditions and reasonable assumptions, COMSOL Multiphysics software was used to develop the hydraulic and mechanical coupling finite element model of the fracture network with different intersection points under normal stress and shear stress, focusing on the study of the effect of normal stress and shear stress on the fracture permeability. The degree of permeability change caused by the normal stress and shear stress is different. The shear stress has a significant influence on the fracture permeability, and when the normal stress is low, the relationship between the fracture permeability and shear stress can be described by a linear relationship. Then, the influence of the number of intersection points in the fracture network on the average fracture width, average water pressure, average seepage velocity and seepage passage of the fractured rock mass was analyzed. The number of intersections in the fracture network has little influence on the average fracture gap width and average water pressure but has a great influence on the flow velocity. The analysis in this paper is very helpful to understand the seepage characteristics in rough fractures under normal stress and shear stress.

EVC-TDMA: An Enhanced TDMA Based Cooperative MAC Protocol for Vehicular Networks

Tianjiao Zhang,Qi Zhu 한국통신학회 2020 Journal of communications and networks Vol.22 No.4

In order to optimize the communication mechanism inthe vehicular adHoc networks (VANETs), this paper presents anenhanced TDMA based cooperative MAC protocol called EVCTDMA. In EVC-TDMA, when the vehicles need to transmit multihop messages, they choose relay nodes dynamically according tothe relative speeds and buffer lengths. By monitoring the broadcasting messages, the other nodes can know the buffer lengths ofthe relay nodes, they will help transmit the relay messages whentheir buffer are idle or less. Considering the data arrive follows aPoison Point Process, this paper analyzes the nodes’ buffer lengthbased on a two-dimension Markov process. The simulation resultsshow that EVC-TDMA can reduce the dropping rate and improvethe throughput of the network.

Bird's Eye View Semantic Segmentation based on Improved Transformer for Automatic Annotation

( Tianjiao Liang ),( Weiguo Pan ),( Hong Bao ),( Xinyue Fan ),( Han Li ) 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.8

High-definition (HD) maps can provide precise road information that enables an autonomous driving system to effectively navigate a vehicle. Recent research has focused on leveraging semantic segmentation to achieve automatic annotation of HD maps. However, the existing methods suffer from low recognition accuracy in automatic driving scenarios, leading to inefficient annotation processes. In this paper, we propose a novel semantic segmentation method for automatic HD map annotation. Our approach introduces a new encoder, known as the convolutional transformer hybrid encoder, to enhance the model's feature extraction capabilities. Additionally, we propose a multi-level fusion module that enables the model to aggregate different levels of detail and semantic information. Furthermore, we present a novel decoupled boundary joint decoder to improve the model's ability to handle the boundary between categories. To evaluate our method, we conducted experiments using the Bird's Eye View point cloud images dataset and Cityscapes dataset. Comparative analysis against state-of-the-art methods demonstrates that our model achieves the highest performance. Specifically, our model achieves an mIoU of 56.26%, surpassing the results of SegFormer with an mIoU of 1.47%. This innovative promises to significantly enhance the efficiency of HD map automatic annotation.

Photocatalytic Activity of Nitrogen-Doped Mesoporous Carbon Spheres Supporting Anatase TiO2 Prepared by a Simple Two-Step Solvothermal Approach

Tianjiao Bi,Jiafeng Wan,Shilin Yang,Xiujuan Yu,Fangwei Ma 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.5

Nitrogen-doped mesoporous carbon spheres (NMCSs) supporting anatase TiO2 (NMCSs – TiO2) were prepared by a simple two-step solvothermal approach. The characterizations for the physicochemical properties of prepared samples under different solvothermal temperatures were carried out by X-ray diffraction (XRD) analyses, scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption – desorption (Brunauer – Emmett – Teller (BET) measurements), Fourier transform infrared (FT-IR) spectroscopy, Raman scattering and UV-Vis diffuse reflectance spectra, were combined in order to determine the crystal phase and grain size, shape, degree of mesoporous carbon incorporation, and nature of the resultant oxy-carbide chemical bonding on the surface and in the bulk. The high relative photocatalytic activity of NMCSs – TiO2 nanoparticle was evaluated through a study of the decomposition of phenol under visible-light excitation.

比较视野下中国式现代化的发展历程与世界意义

裴天娇(Tianjiao Pei) YIXIN 출판사 2023 Journal of China Studies Vol.1 No.3

在世界现代化进程中,各国根据国情和自身发展方式、发展水平等因素,选择了不同的现代化道路。本文基于比较视野,首先分析对比早发内生型与后发外生型两种不同的现代化类型,并从新民主主义革命时期、社会主义革命和建设时期、改革开放和社会主义现代化建设新时期以及中国特色社会主义新时代四个阶段,回顾了中国共产党带领人民探索中国式现代化道路的百年历程。从比较视野来看,中国式现代化走出了超越西方冲突与对抗的人类文明新形态之路、克服西方单一与分化的全体人民共同富裕之路、摆脱西方破坏与污染的人与自然和谐共生之路以及破除西方霸权主义与强权政治的和平发展之路,具有普遍的世界意义。 In the process of global modernization, countries have pursued diverse paths of modernization based on their unique national circumstances, development methods, levels, and other factors. Taking a comparative perspective, this paper firstly analyzes and contrasts two distinct types of modernization: early endogenous modernization and later exogenous modernization, and then reviews the centennial history of the CPC leading the people to explore the Chinese-style modernization from four stages: the new democratic revolution period, the socialist revolution and construction period, the new period of the reform and opening up and socialist modernization, and the new era of socialism with Chinese characteristics. From a global perspective, Chinese-style modernization has paved the way for a new form of human civilization that transcends Western conflicts and confrontations, fosters common prosperity beyond Western singularity and differentiation, promotes harmonious coexistence between humanity and nature, free from Western destruction and pollution, and advances peaceful development by breaking down Western hegemonism and power politics. It holds universal significance for the world.

Game-Based TDMA MAC Protocol for Vehicular Network

Zhang Tianjiao,Zhu Qi 한국통신학회 2017 Journal of communications and networks Vol.19 No.3

A vehicular ad hoc network (VANET) is a special network for vehicle-to-vehicle communication. The proper medium access control (MAC) protocol based on time division multiple access (TDMA) is the key to realizing efficient vehicle-to-vehicle communication. In a VANET, when two or more nodes occupy the same time slot and drive into each other's communication ranges, a reservation collision occurs, and all of the colliding nodes release their slots. This paper presents a game-based TDMA MAC protocol (GAH-MAC) to solve this problem. In this protocol, when a reservation collision occurs, the colliding nodes will play games with each other to decide whether to reserve the original slot or a new one. In this way, the time slots can be fully used, and the reservation speeds can be increased without being controlled by the base stations. The simulation results show that the performance of GAH-MAC is superior in high-density networks, raising the success rate of reservations and increasing network throughput.

From Conceptual Idea to Strategic Reality: ‘Indo-Pacific Strategy’ from the Perspective of Chinese Scholars

Li Li,Tianjiao Jiang 경남대학교 극동문제연구소 2023 ASIAN PERSPECTIVE Vol.47 No.1

Chinese scholars’ research on “Indo-Pacific Strategy” has undergone two shifts. Firstly, they began to pay limited attention to the Indo-Pacific concept and the US Indo-Pacific regional strategy in 2013. With 2017 and 2018 as the turning point, the attention to the Indo-Pacific strategy shows a significant increase. Secondly, regarding the scholars’ judgment of the Indo-Pacific strategy, since the end of 2019, they reach a consensus on their assessment of the strategy, especially on its threat to China. The two main reasons that drove the above shifts were the enrichment of the Indo-Pacific Strategy by the United States and China’s perception of India’s attitudes. China’s official responses to the strategy have shown a co-moving rhythm with scholars’ research, shifting from a more open and neutral attitude toward the concept to a critical one. Against the background of America’s continuing effort to implement the Indo-Pacific strategy, China’s policy responses can focus on three aspects: do a good job of itself, handle China-US relations peacefully and cooperatively, and break down the group politics.

Data-driven Multiplayer Mixed-zero-sum Game Control of Modular Robot Manipulators with Uncertain Disturbance

Xinye Zhu,Tianjiao An,Bo Dong 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.2

This paper develops a data-driven multiplayer mixed-zero-sum game control approach of modular robot manipulators (MRMs) with uncertain disturbance via adaptive dynamic programming (ADP). The dynamic model of MRMs is formulated via joint torque feedback. We deem n modules and uncertain disturbance as players in the game theory structure. The uncertainties in the MRM system such as joint friction and interconnected dynamic couplings (IDCs), we employ data-driven model based on recurrent neural networks (RNNs) to built. According to ADP, the Hamilton-Jacobi (HJ) equation can be solved by using critic neural networks and derivate the optimal control law. The closed-loop robotic system is proved to be asymptotic stable via mixed-zero-sum game control. Experiments are conducted to verify the effectiveness.

Two Indolocarbazole Alkaloids with Apoptosis Activity from a Marine-derived Actinomycete Z2039-2

Rui Liu,Tianjiao Zhu,Dehai Li,Jingyan Gu,Wei Xia,Yuchun Fang,HongbingLiu,Weiming Zhu,Qianqun Gu 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.3

Bioassay-guided fractionation of the EtOAc extract from the fermentation broth of a marinederived actinomycete Z2039-2 led to the isolation of two known indolocarbazole alkaloids, K252c (1) and arcyriaflavin A (2). 1 and 2 exhibited moderate cytotoxic activities against the K562 cell line, and induced apoptotic activities at 10 and 100 µM, respectively. This is the first report on the significant apoptosis inducing effect of indolocarbazole alkaloids against K562 cancer cells.