Synthesis method of new weakly-coupled 5-DOF compliant parallel mechanism

Yajie Zhou,Jing Sun,Fengkui Zhang,Shihua Li 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8

Compared with the strongly-coupled parallel mechanism, the weakly-coupled mechanism can realize two kinds of mutually independent motions. In this paper, a new method for type synthesis of weakly-coupled compliant parallel mechanisms is proposed. The synthesis conditions, that is, the synthesis conditions of the shared flexure hinges and synthesis condition of the weakly-coupled, are given. The synthesis process is formulated. From the perspective of mechanism innovation, a new synthesis idea of weakly-coupled CPMs is introduced. New weakly-coupled CPMs without intermediate platform are obtained by sharing the flexure hinges of two compliant parallel mechanisms. To obtain five degree of freedom (5-DOFs) weakly-coupled compliant parallel mechanisms, two kinds of sub-sets of compliant mechanism blocks, a two-rotation and one-translation compliant mechanism and a twotranslation compliant mechanism are proposed. With the proposed synthesis method, two blocks are indirectly connected by sharing flexure hinges to obtain an integral mechanism. Then, new 5-DOF weakly-coupled compliant parallel mechanisms are proposed by the synthesis conditions. Additionally, finite element simulation is carried out to verify the correctness of the proposed synthesis method. Thirteen new 5-DOF weakly-coupled compliant parallel mechansims have been synthesized, which enriches the compliant parallel mechanism configurations. And, they have simple structure, compact structure, ease of control and light weight. The synthesized 5-DOF weakly-coupled compliant parallel mechanisms have potential application to pointing, vibration isolation and mirror adjustment platform.

Primordial Drivers of Diabetes Heart Disease: Comprehensive Insights into Insulin Resistance

Yajie Fan,Zhipeng Yan,Tingting Li,Aolin Li,Xinbiao Fan,Zhongwen Qi,Junping Zhang 대한당뇨병학회 2024 Diabetes and Metabolism Journal Vol.48 No.1

Insulin resistance has been regarded as a hallmark of diabetes heart disease (DHD). Numerous studies have shown that insulin resistance can affect blood circulation and myocardium, which indirectly cause cardiac hypertrophy and ventricular remodeling, participating in the pathogenesis of DHD. Meanwhile, hyperinsulinemia, hyperglycemia, and hyperlipidemia associated with insulin resistance can directly impair the metabolism and function of the heart. Targeting insulin resistance is a potential therapeutic strategy for the prevention of DHD. Currently, the role of insulin resistance in the pathogenic development of DHD is still under active research, as the pathological roles involved are complex and not yet fully understood, and the related therapeutic approaches are not well developed. In this review, we describe insulin resistance and add recent advances in the major pathological and physiological changes and underlying mechanisms by which insulin resistance leads to myocardial remodeling and dysfunction in the diabetic heart, including exosomal dysfunction, ferroptosis, and epigenetic factors. In addition, we discuss potential therapeutic approaches to improve insulin resistance and accelerate the development of cardiovascular protection drugs.

Representative Batch Normalization for Scene Text Recognition

Yajie Sun,Xiaoling Cao,Yingying Sun 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.7

Scene text recognition has important application value and attracted the interest of plenty of researchers. At present, many methods have achieved good results, but most of the existing approaches attempt to improve the performance of scene text recognition from the image level. They have a good effect on reading regular scene texts. However, there are still many obstacles to recognizing text on low-quality images such as curved, occlusion, and blur. This exacerbates the difficulty of feature extraction because the image quality is uneven. In addition, the results of model testing are highly dependent on training data, so there is still room for improvement in scene text recognition methods. In this work, we present a natural scene text recognizer to improve the recognition performance from the feature level, which contains feature representation and feature enhancement. In terms of feature representation, we propose an efficient feature extractor combined with Representative Batch Normalization and ResNet. It reduces the dependence of the model on training data and improves the feature representation ability of different instances. In terms of feature enhancement, we use a feature enhancement network to expand the receptive field of feature maps, so that feature maps contain rich feature information. Enhanced feature representation capability helps to improve the recognition performance of the model. We conducted experiments on 7 benchmarks, which shows that this method is highly competitive in recognizing both regular and irregular texts. The method achieved top1 recognition accuracy on four benchmarks of IC03, IC13, IC15, and SVTP .

Impact Force Reconstruction of Composite materials based on Improved Regularization Technology

( Yajie Sun ),( Tao Yin ),( Jian Yang ),( Zhiyu Cai ),( Shaoen Wu ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.8

In the structural health monitoring of composite materials, in order to solve the ill-posed problem of impact force reconstruction, regularization techniques are often used to deal with it. Due to the poor convergence of the traditional Tikhonov regularization method, in order to accurately reconstruct the time history of the impact force, this paper improves Tikhonov regularization method and constructs homotopy function with strong convergence. Since the optimal regularization parameters need to be found in the homotopy function, the Newton downhill method is used to find the optimal parameters and the homotopy function can be calculated, which can accurately reconstruct the time history of the impact force. In order to verify the universality of the method in this paper, impact hammers of different materials were used in the experiment in this paper to study and compare the reconstruction effect of impact time history of different impact hammers.

Analysis on Pulse Shaping in Faster-than-Nyquist System

Yajie Ren,Jiancun Fan,Xinmin Luo,Xi Chen 대한전자공학회 2017 대한전자공학회 학술대회 Vol.2017 No.1

In faster-than-Nyquist (FTN) signaling, information symbols are transmitted at a rate higher than that suggested by the Nyquist criterion, which causes unavoidable inter-symbol interference (ISI). As one of the most important part in FTN systems, the selection of shaping pulses draws a lot of attention. Pulse shaping filters are necessary in wireless communication systems to generate band-limited signals and reduce ISI in transmission, and help to decrease the detection complexity as well. For sinc pulses, it has been established that with a small increase in the signaling rate beyond the Nyquist rate, there is no reduction in the minimum Euclidean distance for binary signaling. In this paper, we compare the waveforms of different shaping pulses, and present the ISI with different symbol accelerating factor. Furthermore, we do simulations with different shaping pulses and give the selection of pulses in FTN systems.

中国少数民族地区多元化的民间调解机制

齐亚杰(Yajie Qi) YIXIN 출판사 2023 Journal of China Studies Vol.1 No.1

作为云南世居少数民族之一的彝族,在兰坪县实现脱贫攻坚的基础上,正在经历着经济、政治、文化的快速转化,同时发展中也受到来自社会中各种矛盾的阻拦。由于地理生活环境的影响,彝族地区的习惯法至今还被广泛适用,并且影响着生活的各个方面。当前兰坪彝族地区矛盾纠纷调解工作在国家和社会的双重作用下,展现出一种新的形式,两种力量之间并没有很好调和,反而出现了国家与社会之间的不协调,甚至是国家和社会力量之间的冲突等问题。本文以彝族地区习惯法为切入点,结合相关的国家政策,在原有的纠纷调解机制的基础上,提出合理化的建议,以期化解少数民族地区社会矛盾纠纷,维护少数民族地区良好的社会秩序,促进少数民族地区和谐社会建设。 As one of the ethnic minorities living in Yunnan, the Yi ethnic group is undergoing rapid economic, political, and cultural transformation on the basis of poverty alleviation in Lanping County. At the same time, their development is also hindered by various social contradictions. Due to the influence of geographical living environment, the customary laws of the Yi ethnic group are still widely applied and affect various aspects of life. The current mediation mechanism for conflicts and disputes in the Lanping Yi ethnic area, under the dual role of the state and society, has shown a new form. The two forces are not well coordinated, but instead there have been problems such as disharmony between the state and society, and even conflicts between the state and social forces. This article takes the customary law of the Yi ethnic area as the starting point, combined with relevant national policies, and based on the existing dispute mediation mechanism, proposes reasonable suggestions to resolve social conflicts and disputes in ethnic minority areas, maintain good social order in ethnic minority areas, and promote the construction of a harmonious society in ethnic minority areas.

Response of a rocksalt crystal to electromagnetic wave modeled by a multiscale field theory

Lei, Yajie,Lee, James D.,Zeng, Xiaowei Techno-Press 2008 Interaction and multiscale mechanics Vol.1 No.4

In this work, a nano-size rocksalt crystal (magnesium oxide) is considered as a continuous collection of unit cells, while each unit cell consists of discrete atoms; and modeled by a multiscale concurrent atomic/continuum field theory. The response of the crystal to an electromagnetic (EM) wave is studied. Finite element analysis is performed by solving the governing equations of the multiscale theory. Due to the applied EM field, the inhomogeneous motions of discrete atoms in the polarizable crystal give rise to the change of microstructure and the polarization wave. The relation between the natural frequency of this system and the driving frequency of the applied EM field is found and discussed.

Homogeneous platinum diselenide metal/semiconductor coplanar structure fabricated by selective thickness control

Yang, Yajie,Jang, Sung Kyu,Choi, Haeju,Xu, Jiao,Lee, Sungjoo The Royal Society of Chemistry 2019 Nanoscale Vol.11 No.44

<P>For the realization of two-dimensional material-based high-performance electronic devices, the formation of a stable, high-quality metal-semiconductor contact is a key factor. Platinum diselenide (PtSe2), a group-10 transition metal dichalcogenide, is a promising candidate owing to its unique property of layer-dependent semiconductor-to-semimetal transition. Here, a scalable and controllable method utilizing an inductively coupled plasma treatment is reported for selectively controlling the thickness of PtSe2 flakes. The PtSe2 transforms from a semimetal to a semiconductor when the thickness decreases below 3 nm. A field-effect transistor is fabricated based on the homogeneous platinum diselenide metal/semiconductor coplanar structure (metallic PtSe2 as source/drain electrodes and semiconductor PtSe2 as a channel), which demonstrates a low contact resistance of 362 Ω μm and carrier mobility of 150 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>, outperforming the previously reported PtSe2-based devices.</P>

Plasmonic Transition Metal Carbide Electrodes for High-Performance InSe Photodetectors

Yang, Yajie,Jeon, Jaeho,Park, Jin-Hong,Jeong, Mun Seok,Lee, Byoung Hun,Hwang, Euyheon,Lee, Sungjoo American Chemical Society 2019 ACS NANO Vol.13 No.8

<P>We demonstrate the application of MXenes, metallic 2D materials of transition-metal carbides, as excellent electrode materials for photonic devices. In this study, we have fabricated an InSe-based photodetector with a Ti<SUB>2</SUB>CT<SUB><I>x</I></SUB> electrode. The photodetector with few-layer, atomically thin, Ti<SUB>2</SUB>CT<SUB><I>x</I></SUB> (MXene) electrodes shows the avalanche carrier multiplication effect, which leads to high device performance. To improve the performance of the InSe/Ti<SUB>2</SUB>CT<SUB><I>x</I></SUB> avalanche photodetector, we can pattern Ti<SUB>2</SUB>CT<SUB><I>x</I></SUB> into nanoribbon arrays (a plasmonic grating structure), which enhances light absorption of the photodetector. The plasmonic InSe/Ti<SUB>2</SUB>CT<SUB><I>x</I></SUB> avalanche photodetector exhibits low dark current (3 nA), high responsivity (1 × 10<SUP>5</SUP> AW<SUP>-1</SUP>), and high detectivity (7.3 × 10<SUP>12</SUP> Jones).</P> [FIG OMISSION]</BR>

Effects of transport time and feeding type on weight loss, meat quality and behavior of broilers

Fu Yajie,Yin Jingwen,Zhao Ning,Xue Ge,Zhang Runxiang,Li Jianhong,Bao Jun 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.7

Objective: The purpose of this study is to determine the optimal time of transportation of floor-feed and scatter-feed broilers. Methods: Eighty healthy Arbor Acres (AA) broilers (21-day-old, 624.4 g, male, standard error = 6.65) were selected and randomly divided into two experimental groups (floor-feed and scatter-feed), then fed for three weeks. The experiment comprised a 2×4 factorial design with 2 feed patterns (floor-feed and scatter-feed) and 4 transport periods (2, 3, 4, and 5 h), and 4 replicates of 5 broilers (54-day-old, 2243 g, standard error = 46.65) was used to compare weight loss, meat quality and behavior index of different groups. Results: It appeared that drip loss, meat color and resting behavior of experimental broilers changed as length of transportation (p<0.05), however, weight loss and pH were not significantly transformed (p>0.05). Compared with floor-feed group, broilers in scatter-feed group had lower pH at 24 hours (3 h) and different behavioral indicators (p<0.05). Especially indicators after 3 h transportation, there were obvious differences between the two feeding modes in the behavior reaction of stress events before slaughter with different transport duration (p<0.05). The fluctuation of data on resting behavior with scatter-feed was significantly higher than that of floor-feed broilers. There was no interaction between transport time and different feeding methods for index tested of our experiment (p>0.05). Conclusion: Comprehensive analysis showed that the maximum transport duration of floor-feed and scatter-feed broilers should not exceed 3 h, and scatter-feed broilers were more likely prone to fear. Objective: The purpose of this study is to determine the optimal time of transportation of floor-feed and scatter-feed broilers.Methods: Eighty healthy Arbor Acres (AA) broilers (21-day-old, 624.4 g, male, standard error = 6.65) were selected and randomly divided into two experimental groups (floor-feed and scatter-feed), then fed for three weeks. The experiment comprised a 2×4 factorial design with 2 feed patterns (floor-feed and scatter-feed) and 4 transport periods (2, 3, 4, and 5 h), and 4 replicates of 5 broilers (54-day-old, 2243 g, standard error = 46.65) was used to compare weight loss, meat quality and behavior index of different groups.Results: It appeared that drip loss, meat color and resting behavior of experimental broilers changed as length of transportation (p<0.05), however, weight loss and pH were not significantly transformed (p>0.05). Compared with floor-feed group, broilers in scatter-feed group had lower pH at 24 hours (3 h) and different behavioral indicators (p<0.05). Especially indicators after 3 h transportation, there were obvious differences between the two feeding modes in the behavior reaction of stress events before slaughter with different transport duration (p<0.05). The fluctuation of data on resting behavior with scatter-feed was significantly higher than that of floor-feed broilers. There was no interaction between transport time and different feeding methods for index tested of our experiment (p>0.05).Conclusion: Comprehensive analysis showed that the maximum transport duration of floor-feed and scatter-feed broilers should not exceed 3 h, and scatter-feed broilers were more likely prone to fear.