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Chen Jiang,Yan Xu,Stuti Sharma,Lei Zhang,Jun Song,Wei Qian,Tao Bai,Xiaohua Hou 대한소화기 기능성질환∙운동학회 2019 Journal of Neurogastroenterology and Motility (JNM Vol.25 No.2
Background/Aims The role of psychosocial factors on irritable bowel syndrome (IBS) in adolescents is incompletely understood. The aim of this study is to investigate the association between the psychosocial factors and the risk of developing IBS in college freshmen. Methods A cross-sectional survey was conducted in a randomly selected freshmen population in Wuhan China (n = 2449). Questionnaire evaluated demographics and psychosocial risks. The population was divided into 3 groups: non-discomfort, chronic abdominal discomfort and IBS. The association between the development of IBS and psychosocial factors was analyzed by ordinal and multiple logistic regression analysis. Results A total of 2053 (83.8%) completed this survey (mean age, 18.2 ± 0.9 years; female, 35.6%). Among them, 82 (4.0%) fulfilled the Rome III criteria for IBS. Female (odds ratio [OR], 3.31; 95% confidence interval [CI], 2.47–4.45), experience of abuse (OR, 2.44; 95% CI, 1.10–5.56), and suicidal intention (OR, 2.17; 95% CI, 1.15–4.17) were more likely to have IBS. Compared with chronic abdominal discomfort, however, depression (OR, 5.55; 95% CI, 1.36–22.71) was the only dependent risk factor for IBS. Conclusion The prevalence of IBS in college freshmen is 4.0%, and to the freshmen, psychosocial factors such as experience of abuse, depression, and suicidal intention were associated with high risk of developing IBS.
Chen Jiang,Jialei Huang,Zhenyu Jiang,Dabing Qian,Xiaolan Hong 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.1
Reducing energy use is a major consideration in green manufacturing. Ultrasonic vibration has the advantage of improving machining performance. This work presents an experimental investigation on magnetic compound fluid (MCF) polishing with and without ultrasonic vibration and estimates reductions in polishing energy consumption and surface roughness due to ultrasonic vibration during the machining process. A series of ultrasonic vibration-assisted MCF polishing (UVAMP) tests was carried out for brass H62, and the normal and tangential polishing forces, surface roughness and material removal rate of the traditional MCF polishing (MP) and UVAMP of brass were investigated for various machining parameters. The polishing energy consumptions during traditional MCF polishing and UVAMP were calculated and analyzed from the perspective of the energy of the polishing process. Results indicate that the use of UVAMP considerably reduces energy consumption and surface roughness during the polishing of brass. The adoption of UVAMP therefore has the potential to improve the efficiency and quality of polishing processes and offers a practical solution for the greener manufacturing of brass.
Chen Jiang,Tao Wu,Hui Ye,Jinyi Cheng,Yu Hao 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.6 No.1
Energy and time savings are highly important aspects of green manufacturing. Ultrasonic vibration-assisted grinding (UVAG) is a high-efficiency, low-energy-consumption processing method for optical components made from hard and brittle materials. This work presents an experimental investigation of the specific grinding energy and the subsurface damage depth in UVAG of optical glasses to estimate the increased energy and time savings produced when using UVAG in optical glass manufacturing. The normal and tangential grinding forces of traditional grinding (TG) and axial UVAG processes on optical glasses were investigated for various machining parameters. The specific grinding energies during the TG and UVAG of the optical glasses were calculated and analyzed from the perspective of the energy consumption of the grinding process. The subsurface damage depths in optical glass during TG and UVAG were measured as an estimate of the machining quality, and the magnetorheological polishing spot method was used to analyze the time saved in subsequent polishing processes. The results show that UVAG can reduce energy consumption during the grinding of glass and produce significant time savings in subsequent polishing processes. The UVAG process therefore shows good potential for use in green manufacturing of optical components.
Chen Jiang,Qi Song,Debao Guo,Haolin Li 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.
This work presents an investigation of the minimum dwell time during the precision cylindrical-plunge grinding process. Accordingto the model of acoustic emissions proposed in earlier work, two estimation algorithms of the dwell time, focused on the size errorand the surface roundness of the machined workpiece, are deduced from the models of the material removal and the surfaceroundness, respectively. Based on the proposed estimation algorithms, an on-line estimation method of the minimum dwell time isdeveloped using the measurement and analysis of the acoustic emission signal. A series of experiments of grinding C45 steel areconducted to confirm the validity of the proposed estimation algorithms and determine the model coefficient. The ability of theestimation algorithms to predict the minimum dwell time is deemed necessary for optimal control of the grinding process. In addition,the proposed model provides a new approach to estimate the machined qualities of a workpiece such as the surface roughness andsize error using the dwell time of the grinding process.
Hua Guo,Chenjiang Guo,Jun Ding 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.4
The optimization of the sum and difference patterns for monopulse antennas by a hybrid real/integer-coded invasive weed optimization (IWO) is introduced in this paper. The whole array aperture is divided into several subarrays. The configuration and weight of each subarray are optimized. In order to reduce the difficulty of designing the feeding networks of the array antenna, the elements of the same subarray stay together. Since only the weight and elements number of each subarray is optimized, the number of the optimized parameters is reduced significantly which will reduce the complexity of the simulation procedure. Several numerical simulations are applied to validate the effectiveness of the proposed approach.
Yan Qu,Chenjiang Guo,Xia Zhao,Wencan Peng,Jun Ding 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.4
Phase-only optimization of asymmetric multiple beams reflectarray with single feed is investigated in this paper. The conventional design approaches are first reviewed. Secondly, for design of asymmetric multiple beams reflectarray with arbitrary gain levels and beam directions, a general method based on invasive weed optimization is proposed. Then, practical considerations for applying the proposed method to design multiple beams reflectarray are talked over. For illustrating the effectiveness of the proposed method, several multiple beams design cases with different design requirements are optimized through this method, and the optimized results are analyzed through simulation approach based on array theory. The simulation results show that the optimized cases demonstrate the satisfactory multiple beams performance.
Design of Single-Feed Multi-Beam Reflectarray Using Iterative Fourier Techniques
Yan Qu,Chenjiang Guo,Hua Guo,Jun Ding 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.4
Reflectarray antenna with multiple simultaneous beams is a promising antenna candidate for the multiple beam applications. A comprehensive and systematic study on the design of single-feed multi-beam reflectarray antenna is presented in this paper. The traditional direct design method, called aperture field superposition method, is investigated first. It is demonstrated that although this method can generate a multi-beam pattern, it cannot provide satisfactory performances, mainly because of high side lobe level, gain loss and beam deviation. The iterative Fourier technique is then applied to optimize the performances of the multi-beam reflectarray antenna. The required mask and cost function for multi-beam design and the flow of the iterative Fourier techniques are represented. Finally, a Ku-band four beam reflectarray with a single feed is designed using the iterative Fourier techniques and the radiation performances are analyzed and compared with that of single beam, as reference case, and multiple beam designed by aperture field superposition. The numerical results show that a good four beam performance can be obtained by using the iterative Fourier techniques, which suggests that the iterative Fourier technique is suitable for the design of the multi-beam reflectarray antenna with a single-feed.