Adversarial Complementary Learning for Just Noticeable Difference Estimation

Dong Yu,Jian Jin,Lili Meng,Zhipeng Chen,Huaxiang Zhang 한국인터넷정보학회 2024 KSII Transactions on Internet and Information Syst Vol.18 No.2

Recently, many unsupervised learning-based models have emerged for Just Noticeable Difference (JND) estimation, demonstrating remarkable improvements in accuracy. However, these models suffer from a significant drawback is that their heavy reliance on handcrafted priors for guidance. This restricts the information for estimating JND simply extracted from regions that are highly related to handcrafted priors, while information from the rest of the regions is disregarded, thus limiting the accuracy of JND estimation. To address such issue, on the one hand, we extract the information for estimating JND in an Adversarial Complementary Learning (ACoL) way and propose an ACoL-JND network to estimate the JND by comprehensively considering the handcrafted priors-related regions and non-related regions. On the other hand, to make the handcrafted priors richer, we take two additional priors that are highly related to JND modeling into account, i.e., Patterned Masking (PM) and Contrast Masking (CM). Experimental results demonstrate that our proposed model outperforms the existing JND models and achieves state-of-the-art performance in both subjective viewing tests and objective metrics assessments.

Polydiacetone Acrylamide as Precursors to Polymer Side-Chain Conjugates

Hongzhen Tan,Zhipeng Yu,Junjie Xiao,Xi Wang,Chunwang Yi,Shengpei Su 한국고분자학회 2018 폴리머 Vol.42 No.4

Polydiacetone acrylamide (PDAAM), a reactive polymer containing pendant ketone groups was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Kinetic studies indicated a well-controlled behavior of this RAFT polymerization. The characteristics of this RAFT polymerization was also confirmed by a wellcontrolled chain-extending RAFT polymerization using the above-synthesized PDAAM as a macromolecular chain transfer agent. Acid-catalyzed ketalization of PDAAM with trimethylol propane (TMP) was carried out to obtain the polymer containing pendant cyclic ketal groups and hydroxyl groups, PDAAM-TMP. PCL was grafted from PDAAM-TMP by ring-opening polymerization (ROP) in the presence of tin 2-ethylhexanoate as a catalyst to obtain graft copolymer. Basecatalyzed aldol condensation of PDAAM with benzaldehyde was also used to obtain poly[N-(1,1-dimethyl-3-oxo-5-phenyl-pent-4-enyl)-acrylamide] (PDMOPPEAM) having cinnamoyl groups, and the photoreactivity of polymer with cinnamoyl group was studied by UV-visible and IR absorption spectroscopy. Both of these two polymers prepared from PDAAM were characterized by FTIR and 1H NMR spectroscopy. PDAAM can be a multifunctional platform that can undergo further polymerization by ketalization and aldol condensation.

Structural and functional properties of Maillard-reacted casein phosphopeptides with different carbohydrates

Meng Yuan,Yu Cao,Haoyang Zheng,Kunlin Chen,Yuping Lu,Jing Wang,Liqin Zhu,Ming Chen,Zhipeng Cai,Yonggen Shen 한국식품과학회 2024 Food Science and Biotechnology Vol.33 No.7

This study used glucose, fructose, maltose and dextran to explore the effects of different carbohydrates on the Maillard reaction of casein phosphopeptides (CPP). The color parameter results showed that heating time from 1 to 5 h led to brown color, which was consistent with the observed increased in browning intensity. Fourier transform infrared spectroscopy results verified that four carbohydrates reacted with CPP to produce Maillard conjugates. Fluorescence spectroscopy showed that the Maillard reaction changed the tertiary structure of CPP by decreasing the intrinsic fluorescence intensity and surface hydrophobicity compared with the CPP-carbohydrate mixture. At the same time, the Maillard reaction effectively improved the emulsifying properties, reducing power and DPPH radical scavenging activity of CPP. Furthermore, this study also found that glucose and fructose improved CPP more than maltose and dextran. Therefore, monosaccharides have good potential in modifying CPP via the Maillard reaction.

Facility Performance Indexes and Rapid Test Feasibility Evaluation Method of Shaking Tables

Wei Guo,Zhipeng Zhai,Zhiwu Yu,Yan Long 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.7

Shaking table test is widely used as the main experimental approach to evaluate seismic performance of structures, and it usually consumes huge funds and labors. To ensure success of the tests, it is essential to evaluate the feasibility and accuracy before the test is conducted. However, research on test feasibility has rarely been reported. In recent years, complexity of shaking table tests has increased significantly due to the increasing demand of testing facility performance. Hence, feasibility evaluation becomes more and more important. In this paper, main performance indexes of the shaking table facility are expounded. According to the performance indexes of actuator parameters, a rapid feasibility evaluation method is then proposed based on the equilibrium between the facility capacity and the table output demand. Subsequently, applicability of the evaluation method is validated by evaluating the practical tests. The results show that the maximum acceleration targets in horizontal and vertical direction are mutually restrained under threedimensional excitations. For the feasibility evaluation of large-scale model tests, the eccentric and overturning moment of specimen are the main performance control indexes due to their adverse influences on the facility. And the overturn-resistance of shaking table will be enhanced significantly by vertical actuators during the absence of vertical excitations. In the shaking table array test, millimeter-scale relative displacement between tables may lead to accidental damage of the test specimen or not working of the facility when the reinforced concrete foundation crosses the shaking tables. Therefore, attentions should be paid to the design of the test scheme.

Non-circular gear transmission mechanism with variable-involute and variable-cycloid composite tooth profile

Jiangang Liu,Zhipeng Tong,Gao-Hong Yu,Xiong Zhao,Haili Zhou 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

Non-circular gears with small curvature radius pitch curve are often used in the mechanical transmission of special motion path, but this kind of non-circular gear produces serious undercutting. Therefore, this research presented a kind of variable-involute and variable-cycloid composite tooth profile (VIVC-CTF). A transmission ratio curve of non-circular gear was designed by using Fourier function. The tooth profile equation of VIVC-CTF and its conjugate tooth profile equation were constructed on the basis of the normal and envelope methods. The influence of slip coefficient and ellipse eccentricity on the VIVC-CTF was investigated, and the variation of slip coefficient and eccentricity on the meshing line length, theoretical contact ratio, and pressure angle at pitch curve was analyzed. The meshing experiment of the VIVCCTF non-circular gear transmission mechanism was carried out on the basis of high-speed camera technology. The theoretical results of the transmission ratio were consistent with the experimental results.

PP-TABLF Based Adaptive Command Filter Control for Fully Actuated MSVs with Unknown Uncertainties and Multiple Constraints

Yannan Bi,Zhipeng Shen,Qun Wang,Haomiao Yu,Chen Guo 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.12

This article investigates the adaptive tracking control problem for the marine surface vessels (MSVs) with unknown uncertainties and multiple constraints. Firstly, a novel prescribed performance-based time-varying asystematic barrier Lyapunov function (PP-TABLF) is proposed to control the MSVs to navigate in a variable narrow waterway and to improve the transient performance of MSVs. Secondly, the predictor-based radial basis function neural networks (P-RBFNNs) are developed to approximate the system uncertainties and external disturbances. Specifically, the tracking errors of the RBFNNs are estimated in advance, and the prediction errors are utilized to update the RBFNNs and improve the estimation precision. The command filter and the idea of the recursive sliding mode are integrated with the control law to limit the amplitude of the virtual control signals and to reduce the computational burden. With the proposed control scheme, tracking errors will not override the prescribed performance ranges, and the control force will not be violated in the presence of total unknown uncertainties. Finally, the semi-global uniformly ultimate boundedness of the system is guaranteed by the proposed control scheme, and the simulation results are given to further demonstrate the effectiveness of the proposed approach.

Design of carbonized unidirectional polyimide aerogel for CO2 capture: Effect of pore morphology/topology on CO2 capture

Xinfu Zhao,Yihao Nie,Xibin Yi,Shimo Yu,Jing Zhang,Xiaochan Liu,Zhipeng Yuan,Sijia Liu,Jian Zhang,Guoliang Dou,Mengdi Wang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

Design of efficient CO2 adsorbent is an effective way to capture CO2. Bamboo-derived activated carbon isa promising CO2 adsorbent. Inspired by this, carbonized unidirectional polyimide (CUPI) aerogels werenewly designed by the ice templating method using directional freezing technology. The pore propertyof CUPI aerogel can be tuned by changing the solidification velocity, and a series of CUPI aerogels weredesigned to explore the CO2 capture performance in view of pore morphology/topology. As a result,the obtained CUPI-8 exhibits higher CO2 adsorption capacity compared to carbonized polyimide aerogelsdue to the synergistic effect of micropores and lamellar pores. Specially, the CO2 adsorption capacity overCUPI-8 can be up to 5.75 mmol/g at 20 bar and 298 K. Furthermore, the adsorption isotherm of CUPI-8still shows an upward trend even nearly 20 bar. The isosteric adsorption heat (Qst) value of CUPI-8 isnearly in the ideal scope of 30–50 kJ mol1. The efficient CO2 adsorption performance and good chemicalstability of CUPI aerogel makes it a promising absorbent for practical application. This work provides anew opportunity for researching the effect of pore morphology/topology and the synergistic effect ofhierarchical pores on CO2 capture.

Reliability-based Event Driven Backstepping Positioning Control for a Turret-moored FPSO Vessel with Unknown Slow Time-varying Disturbances

Yulong Tuo,ShashaWang,Chen Guo,Haomiao Yu,Zhipeng Shen 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.2

In this paper, an event driven backstepping positioning controller based on the structural reliability is developed for a turret-moored floating production storage and offloading (FPSO) vessel with unknown slow timevarying disturbances. The mathematical model of the FPSO vessel is given at first. Secondly, to make full use of the positioning capability of mooring system while ensuring the safety of mooring lines, a continuous backstepping positioning controller is designed based on the structural reliability of the mooring system; in the meanwhile, a disturbance observer is designed to handle the unknown disturbances. Then, the proposed event driven positioning controller is achieved based on the designed continuous controller by designing suitable event driven conditions, which can determine the updated time instants of the event driven positioning controller. The proposed positioning controller can not only guarantee the uniform ultimate boundness of the errors for structural reliability and heading but also ensure that no Zeno behavior occurs. Finally, the simulations demonstrate that the proposed event driven positioning controller’s performance while reducing the execution times of FPSO vessel’s actuators.

Facile preparation and characterization of tough poly(vinyl alcohol) organohydrogels with low friction and self-cleaning properties

Jia Yang,Jiajia Hao,Chen Tang,Yaxin Guo,Mingxin Guo,Zhipeng Li,Shuzheng Liu,Hui Yu,Gang Qin,Qiang Chen 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.116 No.-

Although many hydrogels have been applied to wearable sensors, it is still challenging to simultaneouslyrealize hydrogels with optical transparency, superior mechanical properties, excellent sensing performance,and anti-freezing by using inexpensive raw materials and an easy preparation process. Herein,using ethylene glycol/H2O (EG/ H2O) as a solvent, poly(vinyl alcohol)/EG organohydrogel (PVA/EGOHG) was prepared by a simple heating and frozen-thawing method. Owing to the multifunctionalityof EG (i.e., physical cross-linker, anti-freezer and co-solvent), PVA/EG OHG demonstrated excellent integratedproperties, including high strength, high toughness, and anti-freezing performances. Besides, PVA/EG OHG also showed low friction, self-cleaning, and frost resistance properties. After the introduction ofLiCl, ionically conductive PVA/EG @LiCl organohydrogel was served as a self-cleaning strain sensor, whichcould be long-term stable to detect the motions of human under room and low temperatures. The studyprovides to further understanding of the organohydrogel, which will help us design next-generationhigh-performance organohydrogels.