Singularity analysis and workspace optimization of a novel symmetrical 4-limb 5-DOF hybrid robot

Xin Tian,Tieshi Zhao,XiaoXiao Peng,Erwei Li 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.5

Considering the complex structure and large size of multiple axes rotary spindle heads and the small workspace of parallel modules, a 5-degree of freedom (DOF) hybrid robot is proposed, which is a symmetrical 4-limb parallel module in series with a single axis rotary spindle head. Screw theory was used to analyze the mobility and kinematics of the hybrid mechanism. The singularity of the symmetrical 4-limb parallel module was studied, and the analysis results were verified by the Grassmann linear geometry principle. According to the singularity analysis results, the kinematic pairs’ positions of the robot were determined, so the hybrid robot model was constructed. Considering the workspace volume, and optimizing the Latin hypercube sample algorithm, a combinatorial numerical optimization algorithm is proposed to optimize dimension parameters of this hybrid robot, which combines non-linear programming by quadratic Lagrangian (NLPQL) algorithm with the optimized Latin hypercube sampling (Opt LHS) algorithm. Through this optimization algorithm, the workspace volume of the robot is increased by 1.93 times. The research method in this paper is also suitable for the analysis and optimization of other hybrid robots.

Passive Islanding Detection Method for Grid‑Connected Inverters Based on Closed‑Loop Frequency Control

Xintian Liu,Xinxin Zheng,Yao He,Guojian Zeng,Yanan Zhou 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.6

Islanding detection is one of the frontier research problems in the study of distributed grid. The non-detection zone of traditional passive detection method is large, and existing active detection methods for non-detection zones are complicated. Aiming at the above problems, this paper proposes a novel passive islanding detection method with the help of closed-loop frequency control (CFC). In this new method, a high-frequency impedance detection method is combined with CFC to prevent the occurrence of islanding, and the frequency tracking principle and high-frequency impedance characteristics of the CFC are analyzed. Load impedance characteristics under diferent islanding conditions are also discussed. Simulation and experimental results show that proposed method is able to detect the occurrence of inverter disconnection quickly and accurately, and non-detection zone is also eliminated.

An Empirical Study on Relationship of Equity Ownership, Equity Concentration degree and Firm Performance in Chinese Listed Company

Xintian, Zhuang,Ying, Yuan 경성대학교 산업개발연구소 2006 산업혁신연구 Vol.22 No.2

Virtual Synchronous Generator Dynamic Decoupling Technology Based on Complex Vector Current Controller

Liu Xintian,Wang Ketian,Zheng Xinxin,He Yao 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.4

The concept of virtual synchronous generators (VSGs) is an eff ective means for improving the stable operation of the grid when the large number of distributed power sources connected to the grid. However, due to its power coupling problem, coupling overshoot and steady-state error occur during power adjustment, which seriously aff ects the dynamic performance and stability of the system. With this problem in mind, the system model of VSG is established by using a complex vector analysis method. Then the coupling system is analyzed by the bilateral frequency response characteristic curve and pole-zero diagram. On this basis, a dynamic decoupling method based on complex vectors is proposed. Decoupling is obtained by eliminating the poles of the controlled object through the zero points of the controller. After decoupling, when the system performs active power adjustment, the reactive power coupling overshoot is reduced by 83% and the steady-state error is completely eliminated. When the system performs reactive power adjustment, the active power coupling overshoot is reduced by 80%, the dynamic performance and stability of the system have been improved. Simulation and experimental is used to verify the theoretical analysis

테마파크에서의 체험요소가 방문객 몰입과 행동의도에 미치는 영향

이신전(XinTian Li),펑펑(Peng Peng) 한국콘텐츠학회 2015 한국콘텐츠학회논문지 Vol.15 No.6

본 연구는 Pine and Gilmore가 제안한 엔터테인먼트 체험, 현실도피 체험, 미적 체험, 교육체험인 4가지 체험영역을 바탕으로 테마파크 방문객의 몰입에 어떤 영향을 미치는지, 그리고 몰입경험이 테마파크 재방문 및 구전의도에 어떠한 영향을 미치는지 살펴보고자 한다. 실증분석을 위해 테마파크를 방문한 고객을 대상으로 설문조사를 실시하였다. 연구가설을 검증하기 위해 SPSS 18.0과 AMOS 18.0 프로그램을 활용하여 통계분석을 실시하였다. 연구결과를 요약하면 다음과 같다. 첫째, 테마파크 내 미적 체험요소, 교육 체험요소, 엔터테인먼트 체험요소, 현실도피체험요소는 방문객의 몰입에 영향을 미치고 있었다. 둘째, 체험에 대한 방문객의 몰입경험이 증가할수록 재방문/구전의도에 긍정적 영향을 미치는 것으로 나타났다. 셋째, 체험요소는 몰입을 통해 재방문/ 구전의도에 간접적인 영향을 미치고 있었다. 이런 연구결과를 바탕으로 테마파크가 일회성 방문이 아닌 재방문객을 꾸준히 유치하기 위해서는 테마파크에서의 체험의 극대화를 통한 방문객의 몰입도 제고에 더욱 신경 써야 함을 알 수 있다. The purpose of this paper is to examine the structural relationship between experience(4Es), customer commitment and behavioral intention based on experience of the theme park as a hedonic destination. To carry out this study objective, a survey targeted for theme park customers was conducted from May 10. 2014 to June 10. 2014. These data were processed using SPSS 18.0 and Structural Equation Modeling with Amos 18.0 to test proposed hypotheses. The results are summarized as followed. First, the decomposition of path analysis revealed significant positive effects on customer commitment by entertainment experience, education experience, esthetic experience. and escape experience. While, entertainment experience was shown to have the largest influence on customer commitment. Second, customer commitment had a positive effect on revisit intention and WOM. Third, experiences have an indirect influence on revisit intention and WOM through the mediation of commitment. From the findings, the theme park is necessary to plan and develop experience program for more variable and special.

The Empirical Research of M&A Performance of Chinese Listed Company

Zhuang Xintian,Wang Jian 경성대학교 산업개발연구소 2005 산업혁신연구 Vol.21 No.1

Weighted projective lines with weight permutation

Lina Han,Xintian Wang 대한수학회 2021 대한수학회지 Vol.58 No.1

Let $\mathbb X$ be a weighted projective line defined over the algebraic closure $k=\overline{\mathbb F}_q$ of the finite field $\bbf_q$ and $\sigma$ be a weight permutation of $\mathbb X$. By folding the category coh-$\mathbb{X}$ of coherent sheaves on $\mathbb X$ in terms of the Frobenius twist functor induced by $\sigma$, we obtain an $\bbf_q$-category, denoted by coh-$(\mathbb{X},\sigma;q)$. We then prove that $\coh(\mathbb{X},\sigma;q)$ is derived equivalent to the valued canonical algebra associated with $(\bbX,\sigma)$.

MiR-186 Inhibited Migration of NSCLC via Targeting cdc42 and Effecting EMT Process

Ying Dong,Xintian Jin,Zhiqiang Sun,Yueming Zhao,Xianjing Song 한국분자세포생물학회 2017 Molecules and cells Vol.40 No.3

In this study, qRT-PCR was employed to identify that miR-186 expression level in NSCLC tissues are highly associated with lymph node metastasis. In addition, through the application of western blotting, luciferase assay and qRT-PCR, it was found that miR-186 targeted 3UTR of cdc42 mRNA and down-regulated cdc42 protein level in a post-transcriptional manner. Transwell assay indicated that cdc42 partially reversed the effect of miR-186 mimics. Besides, miR-186 was proved to regulate EMT by influencing biomarkers of this process and cell adhesion ability. Thus, miR-186 is a potential target for NSCLC therapy. miR-186 is proposed to be one of tumor-suppressors and may serve as a therapeutic target in NSCLC treatment.

On the characteristics of an ultra-low frequency nonlinear isolator using sliding beam as negative stiffness

Xiuchang Huang,Xintian Liu,Hongxing Hua 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.3

A novel structured ultra-low frequency nonlinear passive isolator is presented. The isolator is composed of a knife-edge supported slidingbeam which offers negative stiffness and a vertical mechanical spring in parallel to get quasi-zero dynamic stiffness. The static characteristicsof the isolator are studied. Assuming light viscous damping, the dynamic behavior is investigated and the response under harmonicexcitation is derived using a simple approximation. Frequency response curves (FRCs), which exhibit complex double jump phenomenon,are obtained by harmonic balance method (HBM). The limitation of the excitation force level is obtained. The force transmissibilityis derived and compared with an equivalent linear system with the same damping ratio. The isolation performance of the nonlinearisolator is shown to outperform the linear system for providing a wider isolation region. The influence of system parameters on thetransmissibility is examined and some useful guidelines are given.

Template-free hydrothermal synthesis of hollow alumina microspheres and its excellent catalytic properties for thiolation

WeiMing Wang,Shuai Peng,XinTian Chen,YingMing Chen,Chuang Peng,Dong Zeng,Jun Xiong,Hao Liu,XiXian Yang,Ming Li 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.118 No.-

In view of the important industrial application value of alumina supports in the field of oil refining andreforming, it is of great significance to develop a simple and economical synthesis method for the hierarchicalporous alumina. Herein, the hollow microsphere alumina was hydrothermally synthesized withouttemplate. The surface of the hollow microsphere alumina supports has a raised fluffy structure, themicrosphere diameter is about 5 8 lm, and the thickness of the shell is about 1 lm. The morphologyevolution process from solid microspheres to core–shell microspheres with spindle-shaped nanoclusters,and then to hollow fluffy microspheres with protruding surface was observed by investigating the effectof hydrothermal synthesis temperature on the morphology of microspheres. Because of its specific morphologyand surface characteristics, the microsphere can better disperse the active component KW toprepare KW/Al2O3 catalyst and used in the thiolation to methyl mercaptan. Compared with our previouslyused catalysts prepared from commercial alumina, this KW/Al2O3 catalyst was not only able togreatly reduce the amount of active component, but also exhibited higher CH3SH selectivity. On the10KW/Al catalyst, the CH3SH selectivity reached 66.2 % at 340 C, which was about 10 % higher than thatof the previous commercial alumina catalyst. This work can provide theoretical basis and practical guidancefor the reasonable design of new alumina support and high efficiency methyl mercaptan catalyst.