Competitive Resource Sharing Based on Game Theory in Cooperative Relay Networks

Guopeng Zhang,Li Cong,Liqiang Zhao,Hailin Zhang,Kun Yang 한국전자통신연구원 2009 ETRI Journal Vol.31 No.1

This letter considers the problem of resource sharing among a relay and multiple user nodes in cooperative transmission networks. We formulate this problem as a sellers’ market competition and use a noncooperative game to jointly consider the benefits of the relay and the users. We also develop a distributed algorithm to search the Nash equilibrium, the solution of the game. The convergence of the proposed algorithm is analyzed. Simulation results demonstrate that the proposed game can stimulate cooperative diversity among the selfish user nodes and coordinate resource allocation among the user nodes effectively.

Atomistic simulations of defect accumulation and evolution in heavily irradiated titanium for nuclear-powered spacecraft

Guopeng Zhang,Bin Cai,Hai Huang,Xiaoting Yuan,Longjingrui Ma,Jiwei Lin Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.6

Titanium alloys are expected to become one of the candidate materials for nuclear-powered spacecraft due to their excellent overall performance. Nevertheless, atomistic mechanisms of the defect accumulation and evolution of the materials due to long-term exposure to irradiation remain scarcely understood by far. Here we investigate the heavy irradiation damage in a-titanium with a dose as high as 4.0 canonical displacements per atom (cDPA) using atomistic simulations of Frenkel pair accumulation. Results show that the content of surviving defects increases sharply before 0.04 cDPA and then decreases slowly to stabilize, exhibiting a strong correlation with the system energy. Under the current simulation conditions, the defect clustering fraction may be not directly dependent on the irradiation dose. Compared to vacancies, interstitials are more likely to form clusters, which may further cause the formation of 1/3<1210> interstitial-type dislocation loops extended along the (1010) plane. This study provides an important insight into the understanding of the irradiation damage behaviors for titanium.

Fundamental impedance‑based digital synchronous rectification scheme for bidirectional CLLC resonant converters

Guopeng Zhang,Xindi Sun,Hao Wang,Yonghui Liu,Haijun Tao,Lulu Huang 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.1

Synchronous rectification (SR) is an effective way to improve the efficiency of CLLC resonant converters. The soft switching of SR is affected by the parasitic capacitance and the zero-crossing point of the current of the secondary inductance. Therefore, based on uncontrolled rectification on the secondary of the converter, the effective range of soft switching for SR under different operating modes is analyzed. A fundamental impedance model is established to obtain the discharge time of the parasitic capacitance and the zero-crossing point of the current of the secondary in the upper resonant frequency mode. The relationship between the SR signals and primary driving signals in different operating modes is summarized, which can improve the operating range of the SR while ensuring soft-switching. This in turn, ensures the operating efficiency of the converter. The calculation method of the turn-ON and turn-OFF times of the SR in different modes is improved. In addition, the proposed SR method can be used in bidirectional CLLC resonant converters that do not have SR functionality. To accomplish this, only the control program needs to be updated. Experimental results on a 200 V 500 W prototype are given to verify the effectiveness of the SR method.

Research on Covert Communication Technology Based on Matrix Decomposition of Digital Currency Transaction Amount

Lejun Zhang,Bo Zhang,Ran Guo,Zhujun Wang,Guopeng Wang,Jing Qiu,Shen Su,Yuan Liu,Guangxia Xu,Zhihong Tian,Sergey Gataullin 한국인터넷정보학회 2024 KSII Transactions on Internet and Information Syst Vol.18 No.4

With the development of covert communication technologies, the number of covert communication technologies using blockchain as a carrier is increasing. However, using the transaction amount of digital currency as a carrier for covert communication has problems such as low embedding rate, large consumption of transaction amount, and easy detection. In this paper, firstly, by experimentally analyzing the distribution of bitcoin transaction amounts, we determine the most suitable range of amounts for matrix decomposition. Secondly, we design a novel matrix decomposition method that can successfully decompose a large amount matrix into two small amount matrices and utilize the elements in the small amount matrices for covert communication. Finally, we analyze the feasibility of the novel matrix decomposition method in this scheme in detail from four aspects, and verify it by experimental comparison, which proves that our scheme not only improves the embedding rate and reduces the consumption of transaction amount, but also has a certain degree of resistance to detection.

Effects of Glucagon-Like Peptide-2-Expressing Saccharomyces cerevisiae Not Different from Empty Vector

( Xi Zhong ),( Guopeng Liang ),( Lili Cao ),( Qi Qiao ),( Zhi Hu ),( Min Fu ),( Hong Bo ),( Qin Wu ),( Guanlin Liang ),( Zhongwei Zhang ),( Lin Zhou ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.10

Saccharomyces cerevisiae (S. cerevisiae) and glucagon-like peptide-2 (GLP-2) have been employed to improve the intestinal development of weaned animals. The goal of this study was to determine whether either exogenous S. cerevisiae or GLP-2 elicits major effects on fecal microbiotas and cytokine responses in weaned piglets. Ninety-six piglets weaned at 26 days were assigned to one of four groups: 1) Basal diet (Control), 2) empty vector-harboring S. cerevisiae (EV-SC), 3) GLP-2-expressing S. cerevisiae (GLP2-SC), and 4) recombinant human GLP-2 (rh-GLP2). At the start of the post-weaning period (day 0), and at day 28, fecal samples were collected to assess the bacterial communities via sequencing the V1-V2 region of the 16SrRNA gene, and piglets’ blood was also sampled to measure cytokine responses (i.e., IL-1β, TNF-α, and IFN-γ). This study revealed that, on the one hand, although S. cerevisiae supplementation did not significantly alter the growth of weaned piglets, it induced increases in the relative abundances of two core genera (Ruminococcaceae_norank and Erysipelotrichaceae_norank) and decreases in the relative abundances of two other core genera (Lachnospiraceae_norank and Clostridiale_norank) and cytokine levels (IL-1β and TNF-α) (p < 0.05, Control vs EV-SC; p < 0.05, rh-GLP2 vs GLP2-SC). On the other hand, GLP-2 supplementation had no significant influence on fecal bacterial communities and cytokine levels, but it produced better body weight and average daily gain (p < 0.05, Control vs EV-SC; p < 0.05, rh-GLP2 vs GLP2-SC). Therefore, altered fecal microbiotas and cytokine response effects in weaned piglets were due to S. cerevisiae rather than GLP-2.

Fault Detection for Two-dimensional Multi State Delay Roesser Systems with Finite Frequency Specifications

Wen Qin,Chen Zhang,Mouquan Shen,Guopeng Wang 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.1

This article investigates the problem of fault detection filtering for two dimensional (2-D) continuousdiscrete systems with multi state delay in finite frequency domain. Firstly, by the Lyapunov-Krasovskii functional (LKF) method, a finite frequency bounded real lemma (BRL) is presented. Secondly, based on the obtained finite frequency BRL, an observer-based finite frequency fault detection filter is provided as a residual generator, which is used to simultaneously minimize the disturbance effect and maximize the fault effect in finite frequency ranges. Finally, simulations confirm the effectiveness of the proposed method.

FUEL-SAVING CONTROL STRATEGY FOR FUEL VEHICLES WITH DEEP REINFORCEMENT LEARNING AND COMPUTER VISION

Han Ling,Liu Guopeng,Zhang Hui,Fang Ruoyu,Zhu Changsheng 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.3

This study uses deep reinforcement learning (DRL) combined with computer vision technology to investigate vehicle fuel economy. In a driving cycle with car-following and traffic light scenarios, the vehicle fuel-saving control strategy based on DRL can realize the cooperative control of the engine and continuously variable transmission. The visual processing method of the convolutional neural network is used to extract available visual information from an on-board camera, and other types of information are obtained through the vehicle’s inherent sensor. The various detected types of information are further used as the state of DRL, and the fuel-saving control strategy is built. A Carla–Simulink co-simulation model is established to evaluate the proposed strategy. An urban road driving cycle and highway road driving cycle model with visual information is built in Carla, and the vehicle power system is constructed in Simulink. Results show that the fuel-saving control strategy based on DRL and computer vision achieves improved fuel economy. In addition, in the Carla–Simulink co-simulation model, the fuel-saving control strategy based on DRL and computer vision consumes an average time of 17.55 ms to output control actions, indicating its potential for use in real-time applications.

Dual‑mode control strategy based on DC‑bus voltage for dual‑active bridge converter in marine electromagnetic transmitter system

Haijun Tao,Changshun Du,Guopeng Zhang,Zheng Zheng 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.2

The marine electromagnetic detection method is the main method for the exploration of marine oil and gas resources. At present, the controlled source circuit of the electromagnetic transmitter is a unidirectional flow of electric energy. When the emission electrodes release the stored energy, the energy cannot be fed back, resulting in an increased DC bus and switch device voltages. The stress increases and the filter capacitors and switch devices are burned, which cannot guarantee the long-term reliable operation of the underwater devices body in the deep sea. A dual-active bridge converter is presented for the controlled source circuit of the electromagnetic transmitter. First, the topology, operating principle, and soft-switching constraints are introduced in detail. Then, a dual-mode control strategy is designed. The inductor current stress optimization control is adopted to ensure a steady-state operation, and the univariate extended phase-shifting sliding mode control is applied to achieve fast energy feedback of the inductive load. Simulation and experimental results show that the proposed circuit significantly reduces the bus voltage effect and switch device voltage stress, improves the efficiency and dynamic performance of the system, and satisfies the needs of deep-sea oil and gas resource exploration.