Uniqueness of meromorphic solutions of a certain type of difference equations

Jun-Fan Chen,Shu-Qing Lin 대한수학회 2022 대한수학회보 Vol.59 No.4

In this paper, we study the uniqueness of two finite order transcendental meromorphic solutions $f(z)$ and $g(z)$ of the following complex difference equation $$A_{1}(z)f(z+1)+A_{0}(z)f(z)=F(z)e^{\alpha(z)}$$ when they share 0, $\infty$ CM, where $A_{1}(z),$ $A_{0}(z),$ $F(z)$ are non-zero polynomials, $\alpha(z)$ is a polynomial. Our result generalizes and complements some known results given recently by Cui and Chen, Li and Chen. Examples for the precision of our result are also supplied.

Global South at 50 and beyond?: The Voice from China for Establishing NIEO

An Chen,Fan Yang,Ershadul Karim 이준국제법연구원 2016 China and WTO Review Vol.2 No.1

Evaluation of Performance Capability for Emergency Management in 31 Provinces of China in 2014-2015

An Chen,Chao Fan 위기관리 이론과 실천 2016 위기관리 이론과 실천 학술대회 Vol.2016 No.08

Performance capability of emergency management refers to the actual performance of the emergency management of an organization, individual or region. The improvement of the government's emergency management capacity is of great significance to the effective response of a country or local emergency. Performance capability evaluation of emergency management for an organization, individual or region can reflect their capability of emergency management, so as to help them make a more clear and comprehensive judgment to the ability of emergency response, enhance the ability of emergency response, promote China’s emergency response capability and reduce the loss of life and property caused by emergency. The report of Evaluation of performance capability for emergency management in 31 provinces of China in 2014-2015 is jointly issued by Public Management Professional Committee in Society of Management Science of China, Ouhua’ antai Risk and Crisis Emergency Research Institute, Emergency Management Institute of Henan Polytechnic University in 21th January, 2016. In the report, firstly, the 10 worst disaster incidents of each province in 2014-2015 are selected, and then every index of the accidents is graded through being analyzed with consulting American evaluation index system for emergency management and the reaction of the different kinds of accidents. At last, the weighted averages of the indexes are worked out. Meanwhile, the performance capability for emergency management in 31 provinces of China in 2014-2015, including precautions, responses and aftermath, is evaluated qualitatively and quantitatively from aspects of natural disasters, human disasters and comprehensive performance. Based on it, the relevant performance capability is ranked and classified according to four grades: excellent, good, medium and poor. The evaluation report shows that comprehensive performance of Beijing and other 5 provinces is excellent; comprehensive performance of Jiangxi and other 13 provinces is good; comprehensive performance of Chongqing and other 10 provinces is medium; comprehensive performance of Tianjin and some other provinces is poor. To sum up, the excellent evaluation depends on whether the reasonable measures have been taken and whether the better result have been seen; the good and medium evaluation implies that there is some situation discovered in those provinces, just like the worse results in several accidents and lack of risk consciousness; the others are evaluated for the poor performance capability because of their faults full from the precautions to the aftermath. The report also attracts some friends from domestic mainstream media, such as the Paper, Sohu, China News, Science Net and China Youth Online, who consider that the performance capability for emergency management of China’s provinces is cognized deeply and the feasible blueprint is drawn on improving capability for emergency management in China through the report.

Real-Time Repairable Interpolation Scheme for CNC Tool Path Processing

Wei Fan,Chen-Han Lee,Ji-Hong Chen 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.12

G01 trajectory is widely-adopted for CNC machining. The piecewise linear trajectory is geometrically discontinuous, bringing about drastic fluctuation of feedrate and acceleration, and causing low machining efficiency and quality. Many methods of trajectory smoothing are developed and applied in CNC system. However some shortcomings exist when these methods were applied in CNC machining. In the existing methods, the following requirements are not satisfied simultaneously: not less than G2 continuity, confined chord error, shape preservation, interpolating G01 points, spatial applicability, real-time performance of algorithm, free geometric form. Considering various requirements of CNC machining, this work develops an interpolation scheme with local repairing function to deal with the possible shape deficiencies of trajectory. The resulting tool path has G2 continuity and is optimized in bending energy under shape-preserving and chord error constraints. Combining with jerk-limited feedrate scheduling, a real-time tool path processing strategy is developed. The simulation demonstrates the proposed method eliminates shape deficiencies, and has apparent advantage in the reduction of contour error, curvature, bending energy and machining time, compared with Zhao’s and Fan’s methods. The experiment demonstrates the advantages of the proposed algorithm in improving the quality of machined surface and machining efficiency, compared with previous methods.

Biodegradable cross-linked poly(L-lactide-co-e-caprolactone) networks for ureteral stent formed by gamma irradiation under vacuum

Xiliang Liu,Song Liu,Youkun Fan,Jin Qi,Xin Wang,Wei Bai,Dongliang Chen,Chengdong Xiong,Lifang Zhang 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

The poly(L-lactide-co-e-caprolactone) (PLCL) ureteral stent creeps and loses shape stability, increasingthe risk of stent tube dislocation. The rubbery biodegradable cross-linked PLCL networks were preparedthrough gamma irradiation under vacuum in the presence of trimethylolpropane triacrylate (TMPTA),pentaerythritol tetraacrylate (PET4A), and pentaerythritol triacrylate (PETA). At a standard sterilizationdose of 25 kGy, the gel content and network density of PLCL networks increased with increasingcrosslinking agent content (1, 3, 5, 7 wt%), and crosslinking efficiency decreased in the order ofPETA > PET4A > TMPTA. The average molecular weight (Mc ) between two crosslinks ranged from 2000to 105 g/mol. To perform the beneficial semi-interpenetrated polymer network and characterized bythe principle, the networks were processed in several doses (25, 50, 75, 100, and 125 kGy). In place ofthe Charlesby-Pinner equation, the irradiation cross-linking followed the Chen-Liu-Tang equation. ThePLCL network with 7 wt% PETA had a gel fraction of 83%, tensile strength of 34.7 MPa, and tensile setvalue as low as 5%. Furthermore, degradation in vitro was slowed down. Thus, PLCL networks with appropriateelasticity and flexibility, inherent biodegradability, and excellent biocompatibility can provide apromising alternative method for soft tissue repair engineering, such as ureteral stents.

Study on the characteristics of zirconia ceramic in three-dimensional ultrasonic vibration-assisted ELID internal grinding

Fan Chen,Guojian Mei,Bo Zhao,Wenbo Bie,Guangxi Li 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.1

Three-dimensional (3D) ultrasonic vibration-assisted ELID grinding, which combines 3D ultrasonic vibration-assistance with electrolytic in-process grinding wheel dressing (ELID), is a compound process that is designed to achieve high-efficiency precision machining. A grinding force model of 3D ultrasonic vibration-assisted ELID grinding was first developed on the basis of the kinematics of a single grit particle and was verified through experimentation. The surface quality then was observed using white light interference profiling. It was demonstrated during the present investigation that the grinding force during 3D ultrasonic vibration-assisted ELID grinding was approximately 20 %~30 % lower than that of twodimensional (2D) ultrasonic vibration-assisted ELID grinding. In addition, the surface roughness (Ra) achieved during 3D ultrasonic vibration-assisted ELID grinding was approximately 40 %~50 % smoother than was achieved under 2D ultrasonic vibration-assisted ELID, and thus 3D ultrasonic vibration-assisted ELID grinding can achieve better surface quality.

ON THE EXISTENCE OF SOLUTIONS OF FERMAT-TYPE DIFFERENTIAL-DIFFERENCE EQUATIONS

Chen, Jun-Fan,Lin, Shu-Qing Korean Mathematical Society 2021 대한수학회보 Vol.58 No.4

We investigate the non-existence of finite order transcendental entire solutions of Fermat-type differential-difference equations [f(z)f'(z)]ⁿ + P²(z)f^m(z + 𝜂) = Q(z) and [f(z)f'(z)]ⁿ + P(z)[∆_𝜂f(z)]^m = Q(z), where P(z) and Q(z) are non-zero polynomials, m and n are positive integers, and 𝜂 ∈ ℂ \ {0}. In addition, we discuss transcendental entire solutions of finite order of the following Fermat-type differential-difference equation P²(z) [f^(k)(z)]² + [αf(z + 𝜂) - 𝛽f(z)]² = e^r(z), where $P(z){\not\equiv}0$ is a polynomial, r(z) is a non-constant polynomial, α ≠ 0 and 𝛽 are constants, k is a positive integer, and 𝜂 ∈ ℂ \ {0}. Our results generalize some previous results.

A template-hatched method towards poly(acrylic acid) hydrogel spheres with ultrahigh ion exchange capacity and robust adsorption of environmental toxins

Fan Yang,Xin Fan,Man Zhang,Chen Wang,Wei-Feng Zhao,Chang-Sheng Zhao 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.69 No.-

Polyacrylic acid/polyethersulfone (PAA/PES) capsules were adopted as templates to synthesize PAA/PES core–shell spheres, and the PES shell of spheres could be removed automatically by the swelling nature of the cross-linked PAA hydrogel core. By using the method, PAA hydrogel spheres were prepared with an ultrahigh ion exchange capacity of 12 meq g−1, and the spheres showed a high adsorption capacity for methylene blue. The PAA-polyacrylamide hydrogel spheres with dual adsorption ability and good mechanical property were also prepared. It was revealed that these two hydrogel spheres can be effectively utilized in the removal of environmental toxins.

Marketization Plot of HTSC Maglev Mass Transportation in China

Fan, J.D.,Chen, Hui,Yang, Jin,Chen, Guoqiang The Korean Society for Railway 2012 International Journal of Railway Vol.5 No.3

The technology of high-temperature superconductive (HTSC) maglev trains has become mature and ready for a commercial use ten years after its first prototype was made by Jiasu Wang and Suyu Wang. However, an appropriate roadmap in applying it to the market is crucial for its success because superconductivity mystery remains veiled and public safety concern may prevent it from being used.

Note on the Shipai biota (Cambrian series 2, stage 4) yielded from a new section (Xiachazhuang) in the Maoping town of Zigui county, western Hubei province, south China

Fan Liu,Feiyang Chen,Yanlong Chen,Zhifei Zhang 대한지질학회 2017 대한지질학회 학술대회 Vol.2017 No.10