A Corpus-based Study on Mandarin Adaptation of English Coronal Fricatives

Liu, Kaiwen 부산외국어대학교 외국어연구소 2023 외국어연구 Vol.36 No.-

This current research examines the adaptation of the English coronal voiceless fricatives /s/ and /ʃ/ in Mandarin Chinese. Drawing on corpus-based approach, the 848 loanwords under investigation were selected from Xin Hua Wai Lai Ci Ci Dian (Xinhua Loanwords Dictionary, 2019). The result reveals four key findings. First, the overall adaptation shows that English coronal fricatives are variably mapped to Mandarin /s/, /ɕ/ and /ʂ/ without showing overwhelming preference. Second, the adaptation is influenced by the position of the adjacent vowels. In the case of English /s/, Mandarin /s/ is the most preferred mapping when /s/ is in the coda, onset, a C cluster and before a schwa. However, when /s/ is in the intervocalic position, Mandarin /ɕ/ takes up nearly half of the adaptation (49.6%). Third, the quality of vowel also influences the adaptation of fricatives. To be more specific, when English /s, ʃ/ are followed by the high front vowel /i/, both /s/ and /ʃ/ are found to be adapted as /ɕ/. When English /s/ or /ʃ/ is not followed by a high front vowel /i/, they can be variably mapped to /s/, /ɕ/ or /ʂ/ in Mandarin. Fourth, the deletion and deviant mapping of English coronal fricatives demonstrate that semantic and orthographic factors also influence the adaptation process.

Using artificial intelligence to solve a smart structure problem

Kaiwen Liu,Jun Gao,Ruizhe Qiu 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.85 No.3

Smart structures are those structure that could adopt some behavior to prevent instability in their responses. The recognition of stability deterioration has been performed through rigid mathematical formulations in control theory and unpredicted results could not be addressed in control systems since they are able to only work under their predefined condition. On the other hand, incorporating all affecting parameters could result in high computational cost and delay time in the response of the systems. Artificial intelligence (AI) method has shown to be a promising methodology not only in the computer science by at everyday life and in engineering problems. In the present study, we exploit the capabilities of artificial intelligence method to obtain frequency response of a smart structure. In this regard, a comprehensive development of equations is presented using Hamilton’ principle and first order shear deformation theory. The equations were solved by numerical methods and the results are used to train an artificial neural network (ANN). It is demonstrated that ANN modeling could provide accurate results in comparison to the numerical solutions and it take less time than numerical solution.

Analysis and Optimization of Asymmetric Hybrid Permanent Magnet Motor for Electric Vehicle

Liu Kaiwen,Shi Liwei,Liu Zhengwei,Wang Wenqiang,Ding Hongshan 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.5

An asymmetric hybrid permanent magnet motor (AHPMM) is proposed for the traditional permanent magnet motor (TPMM) with a large amount of rare earth materials and high cogging torque. The equivalent magnetic circuit model of the motor is established and the factors affecting the fluctuation of cogging torque are analyzed. With the objective of reducing the torque ripple and cogging torque of the AHPMM, the motor is parametrically modeled and analyzed, and multi-objective hierarchical optimization of the motor parameters is carried out using a hybrid algorithm combining the response surface algorithm and the single scan method, which ultimately determines the optimal combination of motor dimensional parameters. The electromagnetic performance of the AHPMM compared to the TPMM is analyzed using the finite element method. The results show that, without any decrease in output torque, the use of rare-earth materials is reduced by 18.5%, the cogging torque and the total harmonic distortion of the No-load back EMF waveform are reduced by 0.78 Nm and 4.7% respectively compared to the TPMM. Finally, a prototype motor is manufactured and the validity of the theoretical analysis and design of the AHPMM is verified through experiments.

A novel Fourier series-neural network hybrid approach for the boundary supporting stiffness identification of a flexible beam

Kaiwen Zhao,Yang Liu,Jingtao Du 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.6

Boundary supporting stiffness is an important structural parameter for status monitoring and defect detection. In this paper, a novel Fourier series-Neural network hybrid approach is proposed to identify the boundary-supporting stiffness of a flexible beam. The transverse displacements of the flexible beam under arbitrary boundary conditions are described using the admissible function constructed by the Fourier series with supplementary terms. The modal characteristics corresponding to the different boundary-supporting stiffness are solved by the energy principle and Rayleigh-Ritz procedures. The effect of the boundary supporting stiffness on the natural frequencies is analyzed. On this basis, the PSO-BP (particle swarm optimization backpropagation) neural network is established to describe the relationship between boundary supporting stiffness and the natural frequencies. The results show that the neural network built by the proposed method has a good effect on stiffness identification and performs better than the common network. By further comparing the results output from the proposed model with those obtained by the finite element method and the experiment, the effectiveness and feasibility of the proposed model in practical application are demonstrated.

Injectable PTHF-based thermogelling polyurethane implants for long-term intraocular application

Kaiwen Zhang,Zengping Liu,Qianyu Lin,Yi Jian Boo,Valerie Ow,Xinxin Zhao,Daniel Soo Lin Wong,Jason Y. C. Lim,Kun Xue,Xinyi Su,Decheng Wu,Xian Jun Loh 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Background: Hydrogels show great potential to be used for intraocular applications due to their high-water content and similarity to the native vitreous. Injectable thermosensitive hydrogels through a small-bore needle can be used as a delivery system for drugs or a tamponading substitute to treat posterior eye diseases with clear clinical potential. However, none of the currently available thermosensitive hydrogels can provide intraocular support for up to 3 months or more. Method: In this study, an injectable polytetrahydrofuran (PTHF)-based thermosensitive hydrogel was synthesized by polyurethane reaction. We examined the injectability, rheological properties, microstructure, cytotoxicity, and in vivo compatibility and stability of the hydrogels in rabbit eyes. Results: We found that the PTHF block type and PTHF component ratio could modulate thermogelation properties of the polyurethane polymers. The PTHF-based hydrogel implants retained normal retinal structure and function. Incorporating bioinert PTHF generated highly biocompatible and more stable thermogels in the vitreous cavity, with gel networks and the presence of polymer still observed after 3 months when other thermogels would have been completely cleared. Moreover, despite lacking hydrolytically cleavable linkages, the polymers could be most naturally removed from the native vitreous by bio-erosion without additional surgical interventions. Conclusion: Our findings suggest the potential of incorporating hydrophobic bioinert blocks to enhance the in vivo stability of supramolecularly associated hydrogels for long-term intraocular applications.

Optimization and Pole-Slot Analysis of a New Type Permanent Magnet Hybrid Pole Motor for Electric Vehicles

Lv Bingchang,Shi Liwei,Liu Kaiwen,Li Lintao,Ding Hongshan 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.5

To reduce the use of rare earth materials and improve the performance of the motor, a new hybrid pole structure is proposed. The equivalent air-gap magnetic density model is established, and the N-th harmonic analytical expression of the air-gap magnetic density under the hybrid pole is derived; The optimal parameters of the hybrid pole structure are obtained by using sensitivity analysis to stratify the optimized parameters, using a mixture of Box-Behnken Design (BBD) method and Multi-Objective Genetic Algorithm-II (MOGA-II) for the first level parameters, and Central Composite Design (CCD) method for the second level parameters. The electromagnetic performance of the motor under different slots was analyzed based on the finite element method, and the results showed that the cogging torque and the no-load back electromotive force total harmonic distortion of the 48-slot compared to the 12-slot motor under the hybrid pole structure decreased by 45.2 and 47.3%, respectively. At the same time, the hybrid pole structure uses 19% less-rare-earth compared to the conventional structure.

High‑speed growth of high‑quality polycrystalline diamond films by MPCVD

Kai Chen,Tao Tao,Wenxiao Hu,Yucong Ye,Kaiwen Zheng,Jiandong Ye,Ting Zhi,Xiwei Wang,Bin Liu,Rong Zhang 한국탄소학회 2023 Carbon Letters Vol.33 No.7

High-quality diamond films have attracted extensive attentions due to their excellent optical and electrical properties. However, several issues, such as random orientation, stress accumulation, and slow growth rate, severely limit its applications. In this paper, high-quality polycrystalline diamond films with highly ordered (100) orientation were prepared by microwave plasma chemical vapor deposition. The effects of growth parameters on the microstructure, quality and residual stress of diamond films were investigated. Experimental results indicate that relatively high temperature at low methane concentration will promote the formation of (100) oriented grains with a low compressive stress. Optimized growth parameters, a methane concentration of 2% along with a pressure of 250 Torr and temperature at 1050 ℃, were used to acquire high growth rate of 7.9 μm/h and narrow full width at half maximum of Raman peak of 5.5 cm? 1 revealing a high crystal quality. It demonstrates a promising method for rapid growth of high-quality polycrystalline diamond films with (100) orientation, which is vital for improving the diamond related applications at low cost.

Effect of Various Retrogression Regimes on Aging Behavior and Precipitates Characterization of a High Zn-Containing Al–Zn–Mg–Cu Alloy

Kai Wen,Baiqing Xiong,Yongan Zhang,Zhihui Li,Xiwu Li,Shuhui Huang,Lizhen Yan,Hongwei Yan,Hongwei Liu 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.3

In the present work, the infl uence of various retrogression treatments on hardness, electrical conductivity and mechanicalproperties of a high Zn-containing Al–Zn–Mg–Cu alloy is investigated and several retrogression regimes subjected to a samestrength level are proposed. The precipitates are qualitatively investigated by means of transmission electron microscopy(TEM) and high-resolution transmission electron microscopy techniques. Based on the matrix precipitate observations, thedistributions of precipitate size and nearest inter-precipitate distance are extracted from bright-fi eld TEM images projectedalong ⟨110⟩ Al orientation with the aid of an imaging analysis and an arithmetic method. The results show that GP zonesand η′ precipitates are the major precipitates and the precipitate size and its distribution range continuously enlarge with theretrogression regime expands to an extent of high temperature. The nearest inter-precipitate distance ranges obtained arequite the same and the average distance of nearest inter-precipitates show a slight increase. The infl uence of precipitates onmechanical properties is discussed through the interaction relationship between precipitates and dislocations.

Measurement and Theoretical Calculation Confirm the Improvement of T7651 Aging State Influenced Precipitation Characteristics on Fatigue Crack Propagation Resistance in an Al–Zn–Mg–Cu Alloy

Kai Wen,Baiqing Xiong,Yongan Zhang,Zhihui Li,Xiwu Li,Lizhen Yan,Hongwei Yan,Hongwei Liu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

Precipitation characteristics influencing fatigue crack propagation contained matrix precipitate, grain boundary precipitateand precipitate free zone for Al–Zn–Mg–Cu alloys. Over-aging treatment could effectively regulate precipitation and then tobe able to change fatigue crack propagation behavior compared with the peak aging state. In the current work, typical T651and T7651 aging tempers of the alloy were extracted via hardness, electrical conductivity and mechanical properties underone-step and two-step aging treatments. Fatigue crack propagation (FCP) rate under them was tested and correspondingprecipitation characteristics and fracture morphology were observed. The results indicated that fatigue crack propagationresistance for the T7651 temper possessed an obvious improvement on the side of that for the T651 temper, which was alsosupported by fracture appearance, including tearing ridge, tearing dimple and fatigue striation. The precipitation observationshowed that the T651 alloy contained GPI zone, GPII zone and ηʹ phase while the T7651 alloy possessed ηʹ phase and η phase.Compared with the T651 temper, matrix precipitate for the T7651 temper distinctly owed an expanding of size distributionand an enlargement of average size while cuttable phase still remained the dominance for both tempers. Grain boundaryprecipitate and precipitate free zone manifested no obvious difference between the two aging tempers. Cut and bypass mechanismsof dislocation–precipitate interactions were used for explanation and it revealed the reinforced cuttable phase was infavor of enhancing fatigue crack propagation resistance. A theoretical model which directly correlated FCP rate with matrixprecipitate characteristics was employed to calculate FCP rate by substituting quantitative precipitate characteristics and thecalculation results were vaguely consistent with the experimental measurement, which proved its reliability and feasibility.