WEAKLY ALMOST PERIODIC POINTS AND CHAOTIC DYNAMICS OF DISCRETE AMENABLE GROUP ACTIONS

Ling, Bin,Nie, Xiaoxiao,Yin, Jiandong Korean Mathematical Society 2019 대한수학회지 Vol.56 No.1

The aim of this paper is to introduce the notions of (quasi) weakly almost periodic point, measure center and minimal center of attraction of amenable group actions, explore the connections of levels of the orbit's topological structure of (quasi) weakly almost periodic points and study chaotic dynamics of transitive systems with full measure centers. Actually, we showed that weakly almost periodic points and quasiweakly almost periodic points have distinct orbit's topological structure and proved that there exists at least countable Li-Yorke pairs if the system contains a proper (quasi) weakly almost periodic point and that a transitive but not minimal system with a full measure center is strongly ergodically chaotic.

Foeniculum vulgare essential oil nanoemulsion inhibits Fusarium oxysporum causing Panax notoginseng root-rot disease

Hongyan Nie,Hongxin Liao,Jinrui Wen,Cuiqiong Ling,Liyan Zhang,Furong Xu,Xian Dong The Korean Society of Ginseng 2024 Journal of Ginseng Research Vol.48 No.2

Background: Fusarium oxysporum (F. oxysporum) is the primary pathogenic fungus that causes Panax notoginseng (P. notoginseng) root rot disease. To control the disease, safe and efficient antifungal pesticides must currently be developed. Methods: In this study, we prepared and characterized a nanoemulsion of Foeniculum vulgare essential oil (Ne-FvEO) using ultrasonic technology and evaluated its stability. Traditional Foeniculum vulgare essential oil (T-FvEO) was prepared simultaneously with 1/1000 Tween-80 and 20/1000 dimethyl sulfoxide (DMSO). The effects and inhibitory mechanism of Ne-FvEO and T-FvEO in F. oxysporum were investigated through combined transcriptome and metabolome analyses. Results: Results showed that the minimum inhibitory concentration (MIC) of Ne-FvEO decreased from 3.65 mg/mL to 0.35 mg/mL, and its bioavailability increased by 10-fold. The results of gas chromatography/mass spectrometry (GC/MS) showed that T-FvEO did not contain a high content of estragole compared to Foeniculum vulgare essential oil (FvEO) and Ne-FvEO. Combined metabolome and transcriptome analysis showed that both emulsions inhibited the growth and development of F. oxysporum through the synthesis of the cell wall and cell membrane, energy metabolism, and genetic information of F. oxysporum mycelium. Ne-FvEO also inhibited the expression of 2-oxoglutarate dehydrogenase and isocitrate dehydrogenase and reduced the content of 2-oxoglutarate, which inhibited the germination of spores. Conclusion: Our findings suggest that Ne-FvEO effectively inhibited the growth of F. oxysporum in P. notoginseng in vivo. The findings contribute to our comprehension of the antifungal mechanism of essential oils (EOs) and lay the groundwork for the creation of plant-derived antifungal medicines.

Weakly almost periodic points and chaotic dynamics of discrete amenable group actions

Bin Ling,Xiaoxiao Nie,Jiandong Yin 대한수학회 2019 대한수학회지 Vol.56 No.1

The aim of this paper is to introduce the notions of (quasi) weakly almost periodic point, measure center and minimal center of attraction of amenable group actions, explore the connections of levels of the orbit's topological structure of (quasi) weakly almost periodic points and study chaotic dynamics of transitive systems with full measure centers. Actually, we showed that weakly almost periodic points and quasi-weakly almost periodic points have distinct orbit's topological structure and proved that there exists at least countable Li-Yorke pairs if the system contains a proper (quasi) weakly almost periodic point and that a transitive but not minimal system with a full measure center is strongly ergodically chaotic.

Real-Time PCR Analysis of Metabolic Pathway of PHB in Acidiphilium cryptum DX1-1

Ai Ling Xu,Jin Lan Xia,Ke Ke Liu,Li Li,Yu Yang,Zhen Yuan Nie,Guan Zhou Qiu 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.1

An Optimal Random Carrier Pulse Width Modulation Technique Based on a Genetic Algorithm

Xu, Jie,Nie, Zi-Ling,Zhu, Jun-Jie The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

Since the carrier sequence is not reproducible in a period of the random carrier pulse width modulation (RCPWM) and a higher harmonic spectrum amplitude is likely to affect the quality of the power supply. In addition, electromagnetic interference (EMI) and mechanical vibration will appear. To solve these problems, this paper has proposed an optimal RCPWM based on a genetic algorithm (GA). In the optimal modulation, the range of the random carrier frequency is taken as a constraint and the reciprocal of the maximum harmonic spectrum amplitude is used as a fitness function to decrease the EMI and mechanical vibration caused by the harmonics concentrated at the carrier frequency and its multiples. Since the problems of the hardware make it difficult to use in practical engineering, this paper has presented a hardware system. Simulations and experiments show that the RCPWM is effective. Studies show that the harmonic spectrum is distributed more uniformly in the frequency domain and that there is no obvious peak in the wave spectra. The proposed method is of great value to research on RCPWM and integrated power systems (IPS).

Parallel Shunt for the Treatment of Transjugular Intrahepatic Portosystemic Shunt Dysfunction

Xuefeng Luo,Ling Nie,Jiaywei Tsauo,Zhu Wang,Chengwei Tang,Xiao Li 대한영상의학회 2013 Korean Journal of Radiology Vol.14 No.3

Objective: To investigate the safety, efficacy and long-term patency of parallel shunts (PS) in the management of the transjugular intrahepatic portosystemic shunt (TIPS) dysfunction. Materials and Methods: Between March 2007 and October 2010, 18 patients (13 men and 5 women) who underwent TIPS revision with the creation of PS were evaluated retrospectively. In the first 10 patients, a 10-mm-diameter Wallgraft endoprosthesis was deployed; in the latter 8 patients, an 8-mm-diameter Fluency endoprosthesis was deployed. Results: The creation of PS was technically successful in all patients. The mean ± standard deviation portosystemic pressure gradient before and after the procedure was 25.5 ± 7.3 mm Hg (range, 16-37 mm Hg) and 10.9 ± 2.3 mm Hg (range, 7-16 mm Hg), respectively. The duration of follow-up was 16.7 ± 10.8 months (range, 6-42 months). The primary shunt patency rates at 12 months after the creation of PS was 70% with Wallgraft endoprostheses and 87.5% with Fluency endoprostheses. Conclusion: TIPS revision with the creation of PS is a safe, effective and durable method for treating shunt dysfunction.

Mode Switching Smooth Control of Transient Process of Grid-Connected 400 Hz Solid-State Power Supply System

Zhu, Jun-Jie,Nie, Zi-Ling,Zhang, Yin-Feng,Han, Yi The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

The mode-switching control of transient process is important to grid-connected 400 Hz solid-state power supply systems. Therefore, this paper analyzes the principle of on-grid and islanding operation of the system with or without local loads in the grid-connected process and provides a theoretical study of the effect of different switching sequences on the mode-switching transient process. The conclusion is that the mode switch (MS) must be turned on before the solid-state switch (STS) in the on-grid process and that STS must be turned off before the MS in the off-grid process. A strategy of mode-switching smooth control for transient process of the system is proposed, including its concrete steps. The strategy utilizes the average distribution of peak currents and the smooth adjustment of peak currents and phases to achieve a no-shock grid connection. The simulation and experimental results show that the theoretical analysis is correct and that the method is effective.

Mode Switching Smooth Control of Transient Process of Grid-Connected 400 ㎐ Solid-State Power Supply System

Jun-Jie Zhu,Zi-Ling Nie,Yin-Feng Zhang,Yi Han 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

The mode-switching control of transient process is important to grid-connected 400 ㎐ solid-state power supply systems. Therefore, this paper analyzes the principle of on-grid and islanding operation of the system with or without local loads in the grid-connected process and provides a theoretical study of the effect of different switching sequences on the mode-switching transient process. The conclusion is that the mode switch (MS) must be turned on before the solid-state switch (STS) in the on-grid process and that STS must be turned off before the MS in the off-grid process. A strategy of mode-switching smooth control for transient process of the system is proposed, including its concrete steps. The strategy utilizes the average distribution of peak currents and the smooth adjustment of peak currents and phases to achieve a no-shock grid connection. The simulation and experimental results show that the theoretical analysis is correct and that the method is effective.

A compression strategy to accelerate LSTM meta-learning on FPGA

NianYi Wang,Jing Nie,JingBin Li,Kang Wang,ShunKang Ling 한국통신학회 2022 ICT Express Vol.8 No.3

Driven by edge computing, how to efficiently deploy the meta-learner LSTM in the resource constrained FPGA terminal equipment has become a big problem. This paper proposes a compression strategy based on LSTM meta-learning model, which combined the structured pruning of the weight matrix and the mixed precision quantization. The weight matrix was pruned into a sparse matrix, then the weight was quantified to reduce resource consumption. Finally, a LSTM meta-learning accelerator was designed based on the idea of hardware–software cooperation. Experiments show that compared with mainstream hardware platforms, the proposed accelerator achieves at least 50.14 times increase in energy efficiency.

Efficiency Optimization of the Active Auxiliary Network in the Phase-Shifted Full-Bridge DC/DC Converter

Cao Mei-He,Nie Zi-Ling,Ai Sheng,Xu Jie 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3

Phase-shifted full-bridge DC/DC converter is widely used in the medium and high power DC/DC conversion, and its efciency is an important index to evaluate the performance of the converter. Phase-shifted full-bridge circuit can easily realize the zero voltage switching (ZVS) of the power devices, but there are also problems such as duty-cycle loss and lagging bridge arms that make it difcult to achieve a wide range of ZVS. The application of active auxiliary network can efectively solve the above problems, but it introduces additional loss. This paper analyzes the phase-shifted full-bridge DC/DC converter with active auxiliary network, the duty cycle-loss suppression and the additional circuit loss, optimizes the circuit parameters to reduce the loss and improve the overall efciency of the converter, verifes the theoretical analysis through experiments. Finally, the efciency advantages of the study for high current output applications are clarifed.