Antioxidant Activities of Novel Small-molecule Polysaccharide Fractions Purified from Portulaca oleracea L.

Yuping Li,Li-Hua Yao,Guan-Jie Wu,Xiao-Fang Pi,Yan-Chun Gong,Ruo-Shong Ye,Chen-Xi Wang 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.6

Novel small-molecule polysaccharide fractions,named POP II and POP III, were purified from Portulacaoleracea L. with average Mw values of 9.25 and 8.03 kDa,respectively. Monosaccharide analysis revealed that POP IIwas composed of Rha, Ara, Man, Glc, and Gal with molarratios of 1: 1.42: 0.44: 0.88: 1.59. POP III was composedof Rha, Ara, Glc, and Gal with molar ratios of 1: 1.16:0.23: 0.59. The antioxidant activities of the fractions wereevaluated using cell-free and cell-mediated radical generatingsystems. POPII and POP III possessed strong antioxidantactivities in both systems. The 2 novel polysaccharidefractions extracted from P. oleracea L. can be developed asnatural antioxidants for treatment of free radical-relateddiseases.

Two-step Holographic Imaging Method based on Single-pixel Compressive Imaging

Jun Li,Yaqing Li,Yuping Wang,Ke Li,Rong Li,Jiaosheng Li,Yangyang Pan 한국광학회 2014 Current Optics and Photonics Vol.18 No.2

We propose an experimental holographic imaging scheme combining compressive sensing (CS) theory with digital holography in phase-shifting conditions. We use the Mach-Zehnder interferometer for hologram formation, and apply the compressive sensing (CS) approach to the holography acquisition process. Through projecting the hologram pattern into a digital micro-mirror device (DMD), finally we will acquire the compressive sensing measurements using a photodiode. After receiving the data of two holograms via conventional communication channel, we reconstruct the original object using certain signal recovery algorithms of CS theory and hologram reconstruction techniques, which demonstrated the feasibility of the proposed method.

A new absorbing foam concrete: preparation and microwave absorbing properties

Xingjun, Lv,Mingli, Cao,Yan, Li,Xin, Li,Qian, Li,Rong, Tang,Qi, Wang,Yuping, Duan Techno-Press 2015 Advances in concrete construction Vol.3 No.2

The foam concrete was fabricated by adding the foaming agent which composite ordinary Portland cement with plant and animal protein into cement paste, and the electromagnetic wave absorption properties were studied for the first time as well. The studies showed that the electromagnetic waves can be absorbed by multiple reflections and scattering within the porous material. Thickness and filling ratio have a great influence on the electromagnetic wave absorbing properties in 2-18 GHz of the foam concrete, the greater the thickness, the better the performance of absorption; filling ratio was about 52 vol.%, the absorbing properties achieved the best.

A GENETIC ALGORITHM BASED ON OPTIMALITY CONDITIONS FOR NONLINEAR BILEVEL PROGRAMMING PROBLEMS

Li, Hecheng,Wang, Yuping The Korean Society for Computational and Applied M 2010 Journal of applied mathematics & informatics Vol.28 No.3

For a class of nonlinear bilevel programming problems in which the follower's problem is linear, the paper develops a genetic algorithm based on the optimality conditions of linear programming. At first, we denote an individual by selecting a base of the follower's linear programming, and use the optimality conditions given in the simplex method to denote the follower's solution functions. Then, the follower's problem and variables are replaced by these optimality conditions and the solution functions, which makes the original bilevel programming become a single-level one only including the leader's variables. At last, the single-level problem is solved by using some classical optimization techniques, and its objective value is regarded as the fitness of the individual. The numerical results illustrate that the proposed algorithm is efficient and stable.

Wear Detection in Gear System Using Hilbert-Huang Transform

Li, Hui,Zhang, Yuping,Zheng, Haiqi The Korean Society of Mechanical Engineers 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.11

Fourier methods are not generally an appropriate approach in the investigation of faults signals with transient components. This work presents the application of a new signal processing technique, the Hilbert-Huang transform and its marginal spectrum, in analysis of vibration signals and faults diagnosis of gear. The Empirical mode decomposition (EMD), Hilbert-Huang transform (HHT) and marginal spectrum are introduced. Firstly, the vibration signals are separated into several intrinsic mode functions (IMFs) using EMD. Then the marginal spectrum of each IMF can be obtained. According to the marginal spectrum, the wear fault of the gear can be detected and faults patterns can be identified. The results show that the proposed method may provide not only an increase in the spectral resolution but also reliability for the faults diagnosis of the gear.

Optimal Diversity-Multiplexing Tradeoff of MIMO Multi-way Relay Channel

Yuping Su,Ying Li 한국전자통신연구원 2013 ETRI Journal Vol.35 No.5

A MIMO multi-way relay channel with full data exchange in which K users exchange messages with each other via the help of a single relay is considered. For the case in which each link is quasi-static Rayleigh fading and the relay is full-duplex, the fundamental diversity-multiplexing tradeoff (DMT) is investigated, and we show that a compress-and-forward relay protocol can achieve the optimal DMT.

Research on vibration control of a transmission tower-line system using SMA-BTMD subjected to wind load

Li Tian,Jingyu Luo,Mengyao Zhou,Wenzhe Bi,Yuping Liu 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.5

As a vital component of power grids, long-span transmission tower-line systems are vulnerable to wind load excitation due to their high flexibility and low structural damping. Therefore, it is essential to reduce wind-induced responses of tower-line coupling systems to ensure their safe and reliable operation. To this end, a shape memory alloy-bidirectional tuned mass damper (SMA-BTMD) is proposed in this study to reduce wind-induced vibrations of long-span transmission tower-line systems. A 1220 m Songhua River long-span transmission system is selected as the primary structure and modeled using ANSYS software. The vibration suppression performance of an optimized SMA-BTMD attached to the transmission tower is evaluated and compared with the effects of a conventional bidirectional tuned mass damper. Furthermore, the impacts of frequency ratios and SMA composition on the vibration reduction performance of the SMA-BTMD are evaluated. The results show that the SMA-BTMD provides superior vibration control of the long-span transmission tower-line system. In addition, changes in frequency ratios and SMA composition have a substantial impact on the vibration suppression effects of the SMABTMD. This research can provide a reference for the practical engineering application of the SMA-BTMD developed in this study.

Gear fault detection and diagnosis under speed-up condition based on order cepstrum and radial basis function neural network

Hui Li,Yuping Zhang,Haiqi Zheng 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.10

Varying speed machinery condition detection and fault diagnosis are more difficult due to non-stationary machine dynamics and vibration. Therefore, most conventional signal processing methods based on time invariant carried out in constant time interval are frequently unable to provide meaningful results. In this paper, a study is presented to apply order cepstrum and radial basis function (RBF) artificial neural network (ANN) for gear fault detection during speedup process. This method combines computed order tracking, cepstrum analysis with ANN. First, the vibration signal during speed-up process of the gearbox is sampled at constant time increments and then is re-sampled at constant angle increments. Second, the re-sampled signals are processed by cepstrum analysis. The order cepstrum with normal, wear and crack fault are processed for feature extracting. In the end, the extracted features are used as inputs to RBF for recognition. The RBF is trained with a subset of the experimental data for known machine conditions. The ANN is tested by using the remaining set of data. The procedure is illustrated with the experimental vibration data of a gearbox. The results show the effectiveness of order cepstrum and RBF in detection and diagnosis of the gear condition.

Seven-bar mechanical press with hybrid-driven mechanism for deep drawing; Part 1: kinematics analysis and optimum design

Hui Li,Yuping Zhang 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.11

The main feature of hybrid-driven linkage is the combination of the motion of a large constant velocity motor with that of a small servomotor via a two-degrees-of-freedom mechanism. Thereby, the hybrid-driven linkage can provide for programmable motion output. In the present study, a mechanical drawing press driven by a hybrid mechanism was optimized for displacement and velocity. An analysis of forward kinematics and an optimum model are presented. The actual displacement curves of the slider can approach the ideal ones by means of a two-step optimization. The dimensions of the linkage and the motion rules of the servomotor were optimized. The flexible features of the hybrid-driven drawing press are effectively demonstrated by three optimum examples. The optimum results validate the advantages of the hybrid-driven seven-bar mechanical press, such as its flexible slider speeds and adjustable strokes for drawing operations. By properly designing the input motion of the servomotor, the slider can pass through the desired trajectories.

Hilbert-Huang transform and marginal spectrum for detection and diagnosis of localized defects in roller bearings

Hui Li,Yuping Zhang,Haiqi Zheng 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.2

This work presents the application of a new signal processing technique, the Hilbert-Huang transform and its marginal spectrum, in analysis of vibration signals and fault diagnosis of roller bearings. The empirical mode decomposition (EMD), Hilbert-Huang transform (HHT) and marginal spectrum are introduced. First, the vibration signals are separated into several intrinsic mode functions (IMFs) by using EMD. Then the marginal spectrum of each IMF can be obtained. According to the marginal spectrum, the localized fault in a roller bearing can be detected and fault patterns can be identified. The experimental results show that the proposed method may provide not only an increase in the spectral resolution but also reliability for the fault detection and diagnosis of roller bearings.