Zheng-Biao Li and Wei-Hong Zhu
– The purpose of this paper is to suggest a new analytical technique called the fractional series expansion method for solving linear fractional differential equations (FDEs).
Abstract
Purpose
The purpose of this paper is to suggest a new analytical technique called the fractional series expansion method for solving linear fractional differential equations (FDEs).
Design/methodology/approach
This method is based on the idea of Kantorovich method, convergent series, and the modified Riemann-Liouville derivative.
Findings
This work suggests a new analytical technique. The FDEs are described in Jumarie’s sense.
Originality/value
It finds a new method for solving linear FDEs. The solution procedure is elucidated by two examples.
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Hong wei Li, Hairong Zhu and Li Pan
To realize the operation optimizing of today’s distribution power system (DPS), like economic dispatch, contingency analysis, and reliability and security assessment etc., it is…
Abstract
Purpose
To realize the operation optimizing of today’s distribution power system (DPS), like economic dispatch, contingency analysis, and reliability and security assessment etc., it is beneficial and indispensable that a faster linear load flow method is adopted with a reasonable accuracy. Considering the high R/X branch ratios and unbalanced features of DPS, the purpose of this paper is to propose a faster and non-iterative linear load flow solution for DPS.
Design/methodology/approach
Based on complex function theory, the derivations of the injection current linear approximation have been proposed for the balanced and the single-, double- and three-phase unbalanced loads of DPS on complex plane. Then, a simple and direct linear load flow has been developed with loop-analysis theory and node-branch incidence matrix.
Findings
The methodology is appropriate for balanced and single-, double- and three-phase hybrid distribution system with different load models. It provides a fast and robust load flow method with a satisfactory accuracy to handle the problems of DPS whenever the load flow solutions are required.
Research limitations/implications
The distributed generators (DGs) with unity or fixed power factors can be easily included. But the power and voltage nodes cannot be dealt with directly and need to be further studied.
Originality/value
By combining the current linear approximation with the loop theory-based method, a new linear load flow method for DPS has been proposed. The method is valid and acute enough for balanced and unbalanced systems and has no convergent problems.
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Abstract
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KyoungOk Kim, Yuta Toyomaru, Hong-Wei Li and Masayuki Takatera
The authors compared garments made in Poland, Japan and China to investigate the effect of country of manufacture (COM) on garment marketability by Japanese and Chinese experts…
Abstract
Purpose
The authors compared garments made in Poland, Japan and China to investigate the effect of country of manufacture (COM) on garment marketability by Japanese and Chinese experts. The purpose of this paper is to investigate the differences between the Japanese and Chinese experts.
Design/methodology/approach
The authors compared ten jackets and ten skirts manufactured by four factories in Poland, Japan and China and one Japanese sample maker using five different textiles. The authors provided the same specifications and sample pattern to each of the garment makers. The garment’s marketability was evaluated by 16 Japanese and 18 Chinese experts using a questionnaire survey, considering garment shape, silhouette, face fabric, sub-materials, anticipated appeal to consumers, sewing and ironing skills, and estimated selling price.
Findings
There were high correlations between the Japanese experts’ estimated selling price and evaluation scores in relation to shape, silhouette and face fabric. There were high correlations between the Chinese experts’ estimated selling price and evaluation scores in relation to all items except for face fabric and buttons. However, there were no significant differences between manufacturing countries. Therefore, the garment quality was not dependent on COM because the manufacturing skills of all selected factories were adequate.
Originality/value
This study experimentally investigated the effect of COM on garment marketability by evaluating garments manufactured in Japan, China and Poland using the same pattern and specification sheet. Moreover, these results show differences between the Japanese and Chinese experts for the COM effect.
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Hong-Wei Ying, Kang Cheng, Li-Sha Zhang, Chang-Yu Ou and Yong-Wen Yang
Deep excavation in soft clay often causes additional deformations to surroundings. Then, if deformations cannot be predicted reasonably, the adjacent buildings may be threatened…
Abstract
Purpose
Deep excavation in soft clay often causes additional deformations to surroundings. Then, if deformations cannot be predicted reasonably, the adjacent buildings may be threatened by the deep excavation. Based on the good field observations from ten deep excavations in Hangzhou, this paper aims to thoroughly investigate the characteristics of wall deflections and ground settlements induced by deep excavations.
Design/methodology/approach
On the basis of good field observation of ten deep excavations, the performances of excavations, supported by contiguous pile in Hangzhou, were studied, and also compared with other case histories.
Findings
The maximum wall deflections (dhm) rang mostly from 0.7 to 1.2 per cent He, where He is the final excavation depth, larger than those in Taipei and Shanghai. The observed maximum ground settlement in the Hangzhou cases generally ranges from 0.2 to 0.8 per cent He. Then, the settlement influence zone extends to a distance of 2.0-4.0 He from the excavation. The relatively large movements and influence zones in Hangzhou may be attributed to low stability numbers, large excavation widths and the creep effect. The excavation width is justified to have a significant influence on the wall deflection. Therefore, to establish a semi-empirical formula for predicting the maximum wall deflection, it is necessary to include the factor of excavation width.
Originality/value
The relevant literature concentrated on the characteristics of deep excavations supported by the contiguous pile wall in Hangzhou soft clay can rarely be found. Based on the ten deep excavations with good field observation in Hangzhou, the characteristics of wall deflection and ground settlements were comprehensively studied for the first time, which can provide some theoretical support for similar projects.
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Cho-Pei Jiang, Yung-Chang Cheng, Hong-Wei Lin, Yu-Lee Chang, Tim Pasang and Shyh-Yuan Lee
Polyetheretherketone (PEEK) is used to manufacture biomedical implants because it has a high strength-to-weight ratio and high strength and is biocompatible. However, the use of…
Abstract
Purpose
Polyetheretherketone (PEEK) is used to manufacture biomedical implants because it has a high strength-to-weight ratio and high strength and is biocompatible. However, the use of fused deposition modeling to print a PEEK results in low strength and crystallinity. This study aims to use the Taguchi method to optimize the printing factors to obtain the highest tensile strength of the printed PEEK object. The annealing effect on printed PEEK object and crystallinity are also investigated.
Design/methodology/approach
This study determines the printing factors including the printing speed, layer thickness, printing temperature and extrusion width. Taguchi experimental design with a L9 orthogonal array is used to print the tensile specimen and carried out the tensile test to compare the tensile strength and porosity. Analysis of variance (ANOVA) is used to determine the experimental error and to determine the optimization printing parameters to obtain the highest tensile strength. A multivariate linear regression analysis is used to obtain the linear regression equation for predicting the theoretical tensile strength. An X-ray analysis is achieved to evaluate the crystalline of printed object. The effect of annealing is investigated to improve the tensile strength of printed part. An intervertebral lumber device is printed to demonstrate the feasibility of the obtained optimization parameters for practical application.
Findings
Taguchi experiment designs nine sets of parameters to print the PEEK tensile specimen. The experimental results and the ANOVA present that the order in which the factors affect the tensile strength for printed PEEK parts is the layer thickness, the extrusion width, the printing speed and the printing temperature. The optimized printing parameters are a printing speed of 5 mm/s, a layer thickness of 0.1 mm, a printing temperature of 395 °C and an extrusion strand width of 0.44 mm. The average tensile strength of printed specimen with the optimized printing parameters is 91.48 MPa, which is slightly less than the theoretical predicted value of 94.34 MPa. After annealing, the tensile strength increases to 98.85 MPa, which is comparable to that for molded PEEK and the porosity decreases to 0.3 from 3.9%. X-ray diffraction results show that all printed and annealed specimens have a high degree of crystallinity. The printed intervertebral lumber device has ultimate compressive load of 13.42 kN.
Originality/value
The optimized printing parameters is suitable for low-price fused deposition modeling machine because it does not involve a table at high temperature and can print the PEEK object with high tensile strength and good crystalline. Annealing parameters offer a good solution for tensile strength improvement.
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Kang Cheng, Xu Riqing, Hong-wei Ying, Lin Cungang and Xiaolu Gan
The purpose of this study is to present a simplified analytical method to estimate ground lateral displacement due to excavation. Excavations of foundation pit will inevitably…
Abstract
Purpose
The purpose of this study is to present a simplified analytical method to estimate ground lateral displacement due to excavation. Excavations of foundation pit will inevitably lead to soil movements that may adversely impact surrounding facilities or structures. Thus, estimation of the ground displacement induced by excavation is essential in engineering practice.
Design/methodology/approach
Based on a theory of elastic mechanics, a simplified analytical method for predicting the ground lateral displacement resulting from foundation pit excavation is proposed.
Findings
As the distance from the soil to the supporting structure increases, the maximum ground lateral displacement decreases nonlinearly but at a reduced rate. Poisson’s ratio of soil has a mild influence on the ground lateral displacement, whereas the influence of the supporting structure’s deflection modes is significant.
Originality/value
The advantage of the proposed simplified analytical method lies in that it considers the supporting structure’s arbitrary deflections, giving it wider practical applicability than previous methods.