Adaptive Adjustment of Compressed Measurements for Wideband Spectrum Sensing

( Yulong Gao ),( Wei Zhang ),( Yongkui Ma ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.1

Compressed sensing (CS) possesses the potential benefits for spectrum sensing of wideband signal in cognitive radio. The sparsity of signal in frequency domain denotes the number of occupied channels for spectrum sensing. This paper presents a scheme of adaptively adjusting the number of compressed measurements to reduce the unnecessary computational complexity when priori information about the sparsity of signal cannot be acquired. Firstly, a method of sparsity estimation is introduced because the sparsity of signal is not available in some cognitive radio environments, and the relationship between the amount of used data and estimation accuracy is discussed. Then the SNR of the compressed signal is derived in the closed form. Based on the SNR of the compressed signal and estimated sparsity, an adaptive algorithm of adjusting the number of compressed measurements is proposed. Finally, some simulations are performed, and the results illustrate that the simulations agree with theoretical analysis, which prove the effectiveness of the proposed adaptive adjusting of compressed measurements.

QoS Route Optimization Algorithm for the Dynamic Traffic and Network Service

Yanping Chen,Yulong Gao 보안공학연구지원센터 2014 International Journal of Future Generation Communi Vol.7 No.6

Transforming the convolution to the (+,-) in legend domain is proposed in this paper. Based on the transformation, the Legend Transformation of service curve and arrive curve is given in the case of independent cross traffic, and the closed expression of stochastic delay and stochastic backlog is obtained. In the paper, we analyze influence of the dynamic of traffic and network to QoS parameter. Based on the analysis result, the QoS analysis in Legend domain is given, and the upper bound of delay and backlog in Legend domain. For the case of non-independent cross traffic, the relationship expression of different traffic is got. And simulation proves that the route optimization algorithm is correct.

Model-free adaptive discrete-time full-order sliding mode constrained control for path following of unmanned surface vessels

Gao Shuang,Hu Hongli,Tuo Yulong,Liang Wei,Huang Zhongyi 대한조선학회 2023 International Journal of Naval Architecture and Oc Vol.15 No.-

Considering the dynamic uncertainty, input saturation, and the discrete characteristics of digital control, a practical path following method is proposed for unmanned surface vessels (USV). Online identification for the heading model with uncertainty is presented based on a data-driven technique. Further, a constrained full-order terminal sliding manifold is constructed based on an auxiliary system to solve the input saturation. A full-order sliding mode heading controller is designed for USV in discrete-time form and the stability analysis is provided. Additionally, integral line of sight (ILOS) guidance law is introduced to generate the desired signal for the path following of USV. Simulations and experiments show that the proposed method is effective to realize tracking the desired path and has better performance than the existing popular method.

Robust output feedback control for dynamic positioning of turret-moored vessels based on bio-inspired state observer and online constructive fuzzy system

Tuo Yulong,Wang Shasha,Guo Chen,Gao Shuang 대한조선학회 2022 International Journal of Naval Architecture and Oc Vol.14 No.1

This paper investigates the dynamic positioning control of turret-moored vessels with uncertainties, unknown disturbances and velocities. Firstly, a bio-inspired state observer is proposed based on the bioinspired neural dynamics model to estimate unknown velocities without vessel dynamics model. Meanwhile, an online constructive fuzzy approximator is designed to approximate uncertainties and unknown disturbances. To ensure fuzzy rules adequate and parsimonious, an online constructive scheme is proposed to adjust the fuzzy system structure without any prior knowledge. Based on the designed state observer and fuzzy approximator, a reliability-based robust output-feedback controller is proposed to make the reliability and heading converge to desired values. A reliability-based matrix is applied into the adaptive fuzzy parameter update law to simplify the stability analysis of closed-loop control system. The convergence of reliability can ensure full utilization of mooring system to maintain the vessel within allowable region. Finally, simulations and comparisons show the performance of proposed methods.

Optical and Magnetic Properties of Copper Doped Zinc Oxide Nanofilms

Shifeng Zhao,Yulong Bai,Jieyu Chen,Alima Bai,Wei Gao 한국자기학회 2014 Journal of Magnetics Vol.19 No.1

Copper doped Zinc Oxide nanofilms were prepared using a simple and low cost wet chemical method. The microstructures, phase structure, Raman shift and optical absorption spectrum as well as magnetization were investigated for the nanofilms. Room temperature ferromagnetism has been observed for the nanofilms. Structural analyses indicated that the films possess wurtzite structure and there are no segregated clusters of impurity phase appreciating. The results show that the ferromagnetism in Copper doped Zinc Oxide nanofilms is driven either by a carrier or defect-mediated mechanism. The present work provides an evidence for the origin of ferromagnetism on Copper doped Zinc Oxide nanofilms.

Identification of Second Order System with Inductive Storage Element Using Signal Compression Method and Applying SMCSPO

Zhou Yudong,Gao Xueguan,Wang Jie,Bao Yulong,Min Cheol Lee 제어로봇시스템학회 2019 제어로봇시스템학회 국제학술대회 논문집 Vol.2019 No.10

In this paper, we propose a new method based on signal compression method (SCM) to identify the system that contains dynamic parameters including the capacitive storage, energy dissipator, inductive storage terms. A typical DC motor system is set up and utilized to describe this method. Based on this method, sliding mode control with sliding perturbation observer (SMCSPO) is applied to design controllers. A simulation is performed to express the significance of thorough estimation of the system for the performance of the controller, and this research also experimentally demonstrates that the controller designed based on the dynamics estimated by the method of this paper can have great output tracking performance in a real physical system.

Proline, Sugars, and Antioxidant Enzymes Respond to Drought Stress in the Leaves of Strawberry Plants

Cunhua Sun,Xuehua Li,Yulong Hu,Pingyi Zhao,Tian Xu,Jian Sun,Xiali Gao 한국원예학회 2015 원예과학기술지 Vol.33 No.5

Drought is a severe abiotic stress that affects global crop production. A drought model was created for ‘Toyonoka’ Fragaria × ananassa, and the effects of drought stress on contents of proline, sugars, and antioxidant enzyme activities were investigated. Strawberry transplants with identical growth were chosen for the experiments and the randomized design included four replications (10 plants per block). The experimental sets differed in the moisture level of the culture medium relative to the range of moisture content as follows: control, 70-85%; mild drought stress, 50-60%; moderate drought stress, 40-50%; and severe drought stress, 30-40%. Drought stress was imposed by limiting irrigation. Plants were sampled and physiological parameters were measured on 0, 2, 4, 6, 8, and 10 days after the commencement of drought stress. The water potential of strawberry leaves decreased in the plants under mild, moderate, and severe stress during the course of the water stress treatment and exhibited a significant difference from the control. Strawberry leaves subjected to drought stress had higher accumulation of proline, sugars, and malondialdehyde, and higher activities of superoxide dismutase, peroxidase, and catalase than leaves of control plants. Malondialdehyde levels increased in parallel with the severity and duration of drought stress. By contrast, antioxidant enzyme activity displayed dynamic responses to drought stress, first increasing and subsequently decreasing as the severity and duration of drought stress increased. These results suggest that strawberry plants respond to drought stress by altering the activities of antioxidant enzymes and the levels of osmotically active metabolites. These biochemical response changes may confer adaptation to drought stress and improve the capacity of plants to withstand water-deficit conditions.

Proline, Sugars, and Antioxidant Enzymes Respond to Drought Stress in the Leaves of Strawberry Plants

Sun, Cunhua,Li, Xuehua,Hu, Yulong,Zhao, Pingyi,Xu, Tian,Sun, Jian,Gao, Xiali Korean Society of Horticultural Science 2015 원예과학기술지 Vol.33 No.5

Drought is a severe abiotic stress that affects global crop production. A drought model was created for 'Toyonoka' Fragaria ${\times}$ ananassa, and the effects of drought stress on contents of proline, sugars, and antioxidant enzyme activities were investigated. Strawberry transplants with identical growth were chosen for the experiments and the randomized design included four replications (10 plants per block). The experimental sets differed in the moisture level of the culture medium relative to the range of moisture content as follows: control, 70-85%; mild drought stress, 50-60%; moderate drought stress, 40-50%; and severe drought stress, 30-40%. Drought stress was imposed by limiting irrigation. Plants were sampled and physiological parameters w ere measured on 0, 2, 4, 6, 8, and 10 days after the commencement of droughts tress. The water potential of strawberry leaves decreased in the plants under mild, moderate, and severe stress during the course of the water stress treatment and exhibited a significant difference from the control. Strawberry leaves subjected to drought stress had higher accumulation of proline, sugars, and malondialdehyde, and higher activities of superoxide dismutase, peroxidase, and catalase than leaves of control plants. Malondialdehyde levels increased in parallel with the severity and duration of drought stress. By contrast, antioxidant enzyme activity displayed dynamic responses to drought stress, first increasing and subsequently decreasing as the severity and duration of drought stress increased. These results suggest that strawberry plants respond to drought stress by altering the activities of antioxidant enzymes and the levels of osmotically active metabolites. These biochemical response changes may confer adaptation to drought stress and improve the capacity of plants to withstand water-deficit conditions.

Exchange of the VP5 of Infectious Bursal Disease Virus in a Serotype I Strain with that of a Serotype II Strain Reduced the Viral Replication and Cytotoxicity

Liting Qin,Xiaole Qi,Honglei Gao,Yulong Gao,Zhigao Bu,Xiaomei Wang 한국미생물학회 2009 The journal of microbiology Vol.47 No.3

Infectious bursal disease virus (IBDV), belonging to Avibirnavirus genus in the Birnaviridae family, consists of two segments of double-strand RNA. There are two distinct serotypes of IBDV, the pathogenic serotype I and the non-pathogenic serotype II. Comparison of the deduced amino acid sequences of a panel of VP5 genes retrieved from GenBank revealed a high identity among strains within the serotype I or serotype II group but a low identity between strains across two serotypes. In this study, we rescued two mosaic viruses, rGtGxVP5 and rGt2382VP5 by exchanging the VP5 gene of a cell culture-adapted serotype I Gt strain with its counterpart of the very virulent IBDV Gx strain, or a non-pathogenic 23/82 strain of the serotype II. In comparison to the parental strain rGt virus, the rGtGxVP5 showed the similar viral replication, cytotoxicity and the ability of inducing apoptosis; however, the other mosaic virus rGt2382VP5 had a lower titer and a reduced cytotoxicity. Although exchange of VP5 within serotype I group did not alter the viral replication and cytotoxicity of Gt strain, exchange of VP5 in the serotype I with that of a serotype II reduced the viral replication and cytotoxicity on chicken embryo fibroblast (CEF) cells. Therefore, the VP5 of serotype II may be one of the factors responsible for the distinct pathogenic features of two serotypes.

Effect of Grinding Parameters on Industrial Robot Grinding of CFRP and Defect Formation Mechanism

Fangyuan Wang,Shanyong Xuan,Zongyu Chang,Kai Jin,Yulong Gao,Hao Wang,Qiye Song 한국정밀공학회 2024 International Journal of Precision Engineering and Vol.11 No.2

The use of industrial robots for grinding CFRP is a green processing method. This method not only allows in-situ repair to reduce unnecessary waste of resources, but also produces no excessive contaminants. The effect of various process parameters, including grinding directions, the mesh size of grinding heads and rotating speed, on the grinding quality of Carbon Fiber Reinforced Polymers (CFRP) using industrial robots was investigated. The mechanism of grinding defects was also studied. According to the experimental results, the CFRP grinding process is mainly controlled by the rotating speed, number of grinding heads, and grinding direction. In particular, high-speed grinding helps to improve the surface quality of CFRP. In turn, the use of diamond grinding heads with too small or too large particles may reduce surface quality. Grinding quality changes with the grinding direction. In the grinding direction between 0° and 90°, the surface roughness increases with the angle (but drops at 60°), and The same trend is observed in the grinding direction between 90° and 150°, whereby the surface roughness increases with the angle (but drops at 120°). The surface quality of CFRP is thereby improved after grinding in the direction of 0°, 60°, 120° and 180°. Furthermore, the fiber pull-out occurs, when the feed direction and fiber orientation are aligned. Finally, the low-frequency vibration easily causes fiber pull-out defects.