The SIMP-SRV Method for Stiffness Topology Optimization of Continuum Structures

Zhou, Xiangyang,Chen, Liping,Huang, Zhengdong Society for Computational Design and Engineering 2007 International Journal of CAD/CAM Vol.7 No.1

In density-based topology optimization, 0/1 solutions are sought. Discrete topological problems are often relaxed with continuous design variables so that they can be solved using continuous mathematical programming. Although the relaxed methods are practical, grey areas appear in the optimum topologies. SIMP (Solid Isotropic Microstructures with Penalization) employs penalty schemes to suppress the intermediate densities. SRV (the Sum of the Reciprocal Variables) drives the solution to a 0/1 layout with the SRV constraint. However, both methods cannot effectively remove all the grey areas. SRV has some numerical aspects. In this work, a new scheme SIMP-SRV is proposed by combining SIMP and SRV approaches, where SIMP is employed to generate an intermediate solution to initialize the design variables and SRV is then adopted to produce the final design. The new method turned out to be very effective in conjunction with the method of moving asymptotes (MMA) when using for the stiffness topology optimization of continuum structures for minimum compliance. The numerical examples show that the hybrid technique can effectively remove all grey areas and generate stiffer optimal designs characterized with a sharper boundary in contrast to SIMP and SRV.

A High Precision Compound Control Scheme Based on Non-singular Terminal Sliding Mode and Extended State Observer for an Aerial Inertially Stabilized Platform

Xiangyang Zhou,Yanjun Shi,Lingling Li,Rui-fang Yu,Libo Zhao 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.6

This paper presents a high precision compound control scheme based on non-singular terminal sliding mode and extended state observer (ESO) for an aerial inertially stabilized platform (ISP) to suppress the effects of multi-source disturbances on the control performance of the ISP. Firstly, a non-singular terminal sliding mode controller is proposed to achieve high disturbance rejection ability, by which the multi-source disturbances are integrally suppressed as an aggregate disturbance. And then, to restrain the chattering effect of the sliding mode control, a disturbance compensation scheme based on the extended state observer is proposed. By the ESO, the disturbances are observed and compensated in real time and hence the chattering effect is significantly alleviated. Meanwhile, a parameter configuration method is proposed to simplify the ESO design. To verify the method, simulations and experiments are conducted. The results show that the proposed compound control scheme has excellent ability in both disturbance rejection and chattering reduction, by which the stabilization precision of the ISP is improved significantly.

Evaluation of structural safety reduction due to water penetration into a major structural crack in a large concrete project

Xiangyang Zhang,Vahid Bayat,Mohammadreza Koopialipoor,Danial Jahed Armaghani,Weixun Yong,Jian Zhou 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.26 No.3

Structural damage to an arch dam is often of major concern and must be evaluated for probable rehabilitation to ensure safe, regular, normal operation. This evaluation is crucial to prevent any catastrophic or failure consequences for the life time of the dam. If specific major damage such as a large crack occurs to the dam body, the assessments will be necessary to determine the current level of safety and predict the resistance of the structure to various future loading such as earthquakes, etc. This study investigates the behavior of an arch dam cracked due to water pressure. Safety factors (SFs), of shear and compressive tractions were calculated at the surfaces of the contraction joints and the cracks. The results indicated that for cracking with an extension depth of half the thickness of the dam body, for both cases of penetration and non-penetration of water load into the cracks, SFs only slightly reduces. However, in case of increasing the depth of crack extension into the entire thickness of the dam body, the friction angle of the cracked surface is crucial; however, if it reduces, the normal loading SFs of stresses and joints tractions reduce significantly.

Logistic Distribution Disruption Management Model Based on Distribution Time Delay

Ren Xiangyang,Zhou Xingyao,Guo Yanan 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.8

Distribution delay is a common problem that causes logistics distribution plan difficult to implement. This paper using the customer satisfaction degree, the vehicle drivers’ satisfaction degree, the logistics company deviation cost and the customer future selection lost cost to measure the disturbing degree of disruption events. In this paper, a Genetic Algorithm based on improved elitist strategy is designed, and using re-scheduling and disruption management to solve the instance respectively, it demonstrated the effectiveness and feasibility of disruption management methods.

Comparative Study of Basic Characteristics of Ordinary and Dark Muscle in Skipjack Tuna (Katsuwonus pelamis)

Shulai Liu,Xiangyang Li,Xuxia Zhou,Xilin Zhang,Yuting Ding 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.5

Differences between ordinary and dark muscleof skipjack tuna (Katsuwonus pelamis) including proximatecomposition, flavor, color, texture, and freshness wereinvestigated. Ordinary muscle had a higher crude proteincontent, but a lower crude lipid content than dark muscle. Alcohols (30.41%) and aldehydes (25.56%) were theprominent flavor compounds present in ordinary muscle,whereas hydrocarbons (39.51%) and ketones (21.81%)were more abundant in dark muscle. Different L*, a*, andb* values were also observed. Texture profile analysis(TPA) showed that dark muscle had higher values foradhesiveness, and lower values for cohensiveness, chewiness,and resilience. After mechanical breaking, large myofibrilfragments were observed in ordinary muscle under phasecontrast microscopy, but not in dark muscle. Freshnessindices, including K values, total volatile basic nitrogen(TVB-N), and thiobarbituric acid (TBA) values of darkmuscle were higher than for ordinary muscle.

The mechanism of mesna in protection from cisplatin-induced ovarian damage in female rats

Xiaohuan Li,Shu Yang,Xiangyang Lv,Haimei Sun,Jing Weng,Yuanjing Liang,Deshan Zhou 대한부인종양학회 2013 Journal of Gynecologic Oncology Vol.24 No.2

Objective: Cisplatin is a widely used chemotherapeutic agent in the treatment of cancers in clinic; but it often induces adverse effects on ovarian functions such as reduced fertility and premature menopause. Mesna could attenuate the cisplatin-induced ovarian damages; however, the underlying mechanism is still unknown. This study aimed to figure out the underlying mechanism of the protection of mesna for ovaries against cisplatin therapy in cancers. Methods: We performed female adult Sprague-Dawley rats into normal saline control (NS), low-dose cisplatin (CL), high-dose cisplatin (CH), CL plus mesna (CL+M), and CH plus mesna (CH+M) groups and detected anti-Müllerian hormone (AMH)-positive follicle, oxidative stress status and anti-oxidative capability in ovaries. Results: AMH-positive follicles were significantly decreased after cisplatin administration, which was significantly reversed when mesna was co-administered with cisplatin. The end product of lipid peroxidation, malondialdehyde (MDA), was significantly increased, but the anti-oxidative enzymatic activity of superoxide dismutase (SOD) and glutathione (GSH) were significantly decreased in cisplatin groups when compared with NS group. In contrast, after co-administration of cisplatin with mesna, MDA was significantly decreased whereas the activity of SOD and the concentration of GSH were increased. Moreover, mesna did not decrease the anti-tumor property of cisplatin in HePG2 cell lines. Conclusion: Cisplatin damages the granulosa cells by oxidative stress to deplete the ovarian reserve and mesna could protect ovarian reserve through anti-oxidation. These results might highlight the mechanism of the protection of mesna for ovarian reserve and open an avenue for the application of mesna as a protective additive in cisplatin chemotherapy in clinical practise.

Association of Alexithymia With Positive Symptoms in Chinese Chronic Schizophrenia Patients With and Without Obesity

Yang Tian,Huixia Zhou,Dongmei Wang,Xiangyang Zhang 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.8

Objective A growing body of research suggests the presence of alexithymia (a form of social cognitive impairment) in patients with schizophrenia (SCZ), which may be related to their psychopathological symptoms. Patients with SCZ exhibit high rates of obesity. Interestingly, studies of the general population have found that alexithymia acts a pivotal role in the development and maintenance of obesity. However, little is known regarding the relationship between obesity, alexithymia, and clinical symptoms in SCZ patients. The study was aim to explore the relationship between obesity, alexithymia, and clinical symptoms in SCZ patients.Methods Demographic and clinical data were collected from 507 patients with chronic SCZ. Their symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS), and alexithymia was assessed with the Toronto Alexithymia Scale (TAS).Results Compare with nonobese SCZ patients, obese SCZ patients scored higher on PANSS positive symptoms, TAS total score, difficulty identifying feelings, and difficulty describing feelings (all p<0.05). Correlation analysis revealed a significant association between difficulty identifying feelings and positive symptoms in SCZ patients. Further correlation analysis showed that this association was only present in obese SCZ patients (p<0.05).Conclusion Obesity may moderate the association between alexithymia and positive symptoms in chronic SCZ patients.

Target alignment method of inertial confinement fusion facility based on position estimation

Lin Weiheng,Zhu Jianqiang,Liu Zhigang,Pang Xiangyang,Zhou Yang,Cui Wenhui,Dong Ziming 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.10

Target alignment technology is one of the most critical technologies in laser fusion experiments and is an important technology related to the success of laser fusion experiments. In this study, by combining the open-loop and closed-loop errors of the target alignment, the Kalman state observer is used to estimate the position of the target, which improves the observation precision of the target alignment. Then the optimized result is used to guide the alignment of the target. This method can greatly optimize the target alignment error and reduce uncertainty. With the improvement of the target alignment precision, it will greatly improve the reliability and repeatability of the experiments’ results, thereby improving the success rate of the experiments.