A novel bio-inspired approach with multi-resolution mapping for the path planning of multi-robot system in complex environments

Yi Xin,Zhu Anmin,Li Chaofan,Yang Simon X 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.6

For multi-robot systems (MRSs), conventional path planning with single resolution mapping is challenging to balance information and computation. Regarding path planning of MRS, the previous research lacked systematic definition, quantitative evaluation, and the consideration of complex environmental factors. In this paper, a new systematic formulation is proposed to redefine the multi-robot path planning problem in complex environments, and evaluate the related solutions of this problem. To solve this problem, a novel bio-inspired approach based on reaction-diffusion system is given to deal with the path planning of MRS in complex environments, such as electromagnetic interference, ocean currents, and so on. Furthermore, a multi-layer neural dynamic network is proposed to describe environments with multiple resolutions, which can improve time performance while ensuring the integrity of environmental information. Comparative experimental results indicate that the proposed approach shows the excellent path planning performance of MRS in complex environments. The stability of the proposed method is determined by the mathematical basis.

Walking load model for single footfall trace in three dimensions based on gait experiment

Yixin Peng,Jun Chen,Guo Ding 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.5

This paper investigates the load model for single footfall trace of human walking. A large amount of single person walking load tests were conducted using the three-dimensional gait analysis system. Based on the experimental data, Fourier series functions were adopted to model single footfall trace in three directions, i.e. along walking direction, direction perpendicular to the walking path and vertical direction. Function parameters such as trace duration time, number of Fourier series orders, dynamic load factors (DLFs) and phase angles were determined from the experimental records. Stochastic models were then suggested by treating walking rates, duration time and DLFs as independent random variables, whose probability density functions were obtained from experimental data. Simulation procedures using the stochastic models are presented with examples. The simulated single footfall traces are similar to the experimental records.

Comparative Study Based on Two Kinds of Mobile Ad Hoc Network Routing Protocols

Yixin Yan,Huamin Wang 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.11

A mobile ad hoc network is a special kind of wireless mobile communication network, featuring equal status of all terminals, ad hoc, no need for prior arrangement of any network facilities or central control nodes, dynamically changing topology and bandwidth and energy restriction. In recent years, research on mobile ad hoc networks, especially research on media access control and routing protocols have research focus. In this paper, the well-known on-demand routing protocol AODV is analyzed and is improved as AODV-CLMP, with a simulation platform used to evaluate its performance, with some meaningful conclusions drawn. In this paper, the origin, characteristics, application and current development of mobile ad hoc networks are introduced briefly, followed by research on two kinds of well-known on-demand routing protocols for mobile ad hoc networks, i.e. AODV and AODV-CLMP. Finally, commonly used network simulation software is compared to conduct evaluation and analysis of the performance of the AODV and AODV-CLMP protocols. Through the analysis of the simulation result of such evaluation indicators as average end-to-end delay, packet delivery fraction and throughput, the following conclusions are drawn: the average delay, packet deliveryfractionand throughput of AODV-CLMP protocol are superior to those ofAODV protocol, indicating thatAODV-CLMP protocol can transmit information more rapidly and steadily.

A Virtual Resistance Based Reactive Power Sharing Strategy for Networked Microgrid

Yixin Zhu,Baoquan Liu,Feng Wang,Fang Zhuo,Yangjie Zhao 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Different from the traditional microgrid with a common ac bus, networked microgrid always suffers more serious reactive power sharing problems due to its complex inner configurations. In such a situation, the reactive power sharing errors among distributed generation (DG) units can’t be eliminated effectively. Thus, an advanced reactive power sharing strategy that employs communication and virtual resistance control is hereby proposed for networked microgrid. First of all, the relation between reactive power output and virtual impedance regulation (VRR) is discussed. After that, communication is introduced to assign reactive power reference to each DG unit for their respective VRR, which is able to compensate the mismatch in network. The method is immune to the load change during the regulation stage, and also to the time delay in communication channels. From the small signal analysis, it also can be seen that in the designed regulation range, VRR has no significant effect on the system stability. The feasibility and effectiveness of the proposed strategy are validated by the simulation and real time digital simulator (RTDS) test results from a 50 kVA networked microgrid system.

Reconstruction of a Volatility Based on the Black-Scholes Option Pricing Model Using Homotopy Perturbation Inversion Method

Yixin Dou,Jianhua Fu,Zhihao Wang 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.9

The reconstruction of a volatility based on a Black-Scholes option pricing model is ill-posed. In order to overcome the ill-posedness, a homotopy perturbation inversion method is designed to solve the inverse problem. The proposed method is a modified version of the Landweber method. The reconstruction of a volatility is a nonlinear problem which is needed to be linearized. Hence, numerical experiments consist of the reconstruction of a policy parameter based on a Todaro model which is a linear inverse problem and the reconstruction of a volatility based on a Black-Scholes option pricing model in order to test the performance of the proposed method. Numerical examples show that the proposed method is more accurate and faster than the Landweber method.

Catalytic Conversion of Cellulose to Cellulose Acetate Propionate (CAP) Over SO42−/ZrO2 Solid Acid Catalyst

Yixin Leng,Yun Zhang,Chunxiang Huang,Xiaocheng Liu,Yuzhen Wu 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.4

The solid super acid catalyst SO4 2−/ZrO2 was prepared by impregnation method using ZrO2 as the catalyst support. Catalyst forming was taken into consideration in order to separate catalyst from the mixture of cellulose acetate propionate (CAP). Al2O3 and sesbania gum powder were selected as binding agent and auxiliary agent respectively. The catalytic properties were evaluated through esterification of cellulose with acetic anhydride, propionic anhydride and characterized by XRD, FTIR and NH3-TPD. In this paper, the effects of concentration of H2SO4 impregnated, calcination temperature, esterification temperature and esterification time on the yield, acyl content and viscosity of CAP were investigated. The results showed that SO4 2−/ZrO2 successfully catalyzed CAP synthesis over catalysts impregnated in 0.75 mol/L H2SO4 and calcined at 500 oC. The yield, acetyl content and propionyl content of CAP reached the maximum value of 105.3%, 29.9% and 25.8% reacted at 50 oC for 8 h.

Refolding of Proteins at High Concentration by Size Exclusion Chromatography

Yixin Guan,Gao Shanjing Yao,Man-Gi Cho 한국생명과학회 2002 한국생명과학회 심포지움 Vol.37 No.-

Renaturation of Lysozyme by size exclusion chromatography(SEC) to improve yield as well as the initial and final protein concentration has been studied in detail. Although urea decreases the rate of proteins refolding, it can suppress protein aggregation to sustain pathway of correct refolding at high protein concentration, and there existed an optimum urea concentration in renaturation buffer. Lysozyme was successfully refolded from initial protein concentration of up to 100㎎/ml by SEC, the yield was more than 40%. And the refolding of Interferon-γ was further investigated.

Evaluation and trend of fashion design research: visualization analysis based on CiteSpace

Yixin Zou,Sarawuth Pintong,Tao Shen,Ding-Bang Luh 한국의류학회 2022 Fashion and Textiles Vol.9 No.1

Fashion or apparel refers to a topic discussed publicly as an indispensable discipline on a day-to-day basis, which has aroused rising attention from academic sessions over the past two decades. However, since the topic of fashion design covers knowledge in extensive ranges and considerable information, scholars have not fully grasped the research feld of fashion design, and the research lacks directional guidance. To gain more insights into the existing research status and fronts in the fashion design feld, this study conducts a quantitative literature analysis. The research of this study is conducted by employing CiteSpace technology to visualize and analyze 1388 articles regarding “fashion design” in the Web of Science (WOS) Core Collection. To be specifc, the visualization and the analysis concentrate on the annual number of articles, author collaboration, institutional collaboration, literature citations, keywords clustering, and research trend evolution of the mentioned articles. As highlighted by this study, the efect of the US and the UK on academic research in fashion design is relatively stronger and extensive. Sustainable fashion refers to the research topic having aroused more attention since 2010, while new research topics over the past few years consist of “wearable fashion”, “transgender fashion” and “medical fashion”. The overall research trend of fashion design is developing as interdisciplinary cross research. This study systematically reviews the relevant literature, classifes the existing research status, research hotspots and frontier trends in the academic feld of “fashion design”, and presents the knowledge map and information of literature for researchers in relevant felds

Solubility of D-p-hydroxyphenylglycine p-toluenesulfonate and L-p-hydroxyphenylglycine in different solvents

Yixin Qu,Shui Wang,Tian Li 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.10

The solubility of D-p-hydroxyphenylglycine p-toluenesulfonate and L-p-hydroxyphenylglycine in different solvents was measured using a laser monitoring observation technique. The solubility data were accurately correlated by the modified Apelblat equation, the calculated results of which were proved to show fine representation of experimental data.

Mycosis Fungoides and Variants of Mycosis Fungoides: A Retrospective Study of 93 Patients in a Chinese Population at a Single Center

( Yixin Luo ),( Zhaorui Liu ),( Jie Liu ),( Yuehua Liu ),( Wei Zhang ),( Yan Zhang ) 대한피부과학회 2020 Annals of Dermatology Vol.32 No.1

Background: Mycosis fungoides (MF) is the most common types of cutaneous T cell lymphoma. It typically presents with erythematous patches and plaques in the early stage and tumors and extracutaneous involvement with possibly fatal outcomes in the late stage. To facilitate early and accurate diagnosis of MF, it is essential to be knowledgeable of classic and variants of this disease. However, there is limited published data in the Chinese population. Objective: To characterize our patient group and to provide additional insight into these malignancies. Methods: Patients diagnosed with mycosis fungoides and its variants from October 2012 to January 2018 were retrospectively analyzed. Disease-specific survival (DSS) rate and curve according to early and advanced stages were also calculated. Results: The mean age at diagnosis of ninety-three MF patients was 38.9±1.73 years (range: 6∼77). Forty-five males (48.4%) and 48 females (51.6 %) were included in this study. The DSS rate of early- stage MF was 98.6%, while that of advanced stage MF was 88.9%. There was a significant difference in DSS rate between early stage and advanced stage MF (p=0.042, logrank test). The median age of 10 patients with hypopigmented MF (hMF) was 10.5 years (range: 6∼28). The age of hMF was younger than that of classical MF patients (p <0.05). Conclusion: Early-stage MF has a better prognosis than advanced stage and hMF affects younger people than classic MF among Chinese. This study provides an insight into mycosis fungoides and its variants in a Chinese population. (Ann Dermatol 32(1) 14∼20, 2020)