中国的渔船文化

郑世忠(Zheng Shi-Zhong) 동북아시아문화학회 2009 동북아시아문화학회 국제학술대회 발표자료집 Vol.2009 No.5월

A novel design method for improving collapse resistances of multi-story steel frames with unequal spans using steel braces

Zheng Tan,Wei-hui Zhong,Bao Meng,Shi-chao Duan,Hong-chen Wang3,Xing-You Yao,Yu-hui Zheng 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.47 No.2

The bearing capacities resisted by the two-bay beams of multi-story planar frames with unequal spans under column removal scenarios differ considerably owing to the asymmetric stress on the left and right beams connected to the failed column and cause the potential for beams with larger span-to-depth ratios to be unable to exert effectively, which is disadvantageous for resisting the vertical load in unequal-span frame structures. To address this problem, the structural measure of adding braces to the weak bays of multi-story unequal-span frames was proposed, with the objective of achieving a coordinated stress state in two-bay beams with unequal spans, thereby improving the collapse resistance of unequal-span frame structures. Before conducting the numerical simulation, the modeling methods were verified by previous experimental results of two multi-story planar frames with and without steel braces. Thereafter, the effects of the tensile and compressive braces on the collapse behavior of the frame structures were elucidated. Then, based on the mechanical action laws of the braces throughout the collapse process, a detailed design method for improving the collapse resistance of unequal-span frame structures was proposed. Finally, the proposed design method was verified by using sufficient example models, and the results demonstrated that the design method has good application prospects and high practical value.

Balloon dilation of epidermolysis bullosa-related esophageal strictures: A report of two cases

Wei-Zhong Zhou,Jing-Guo Xia,Zheng-Qiang Yang,Chun-Gao Zhou,Lin-Bo Zhao,Sheng Liu,Hai Bin Shi 소화기인터벤션의학회 2018 International journal of gastrointestinal interven Vol.7 No.3

Epidermolysis bullosa (EB) is a very rare inherited disease featured with skin blistering resulting from minor trauma. Sometimes the esophageal mucosa could also be involved, which leads to esophageal strictures. Here we report two cases of EB-related esophageal strictures who were successfully treated with esophageal balloon dilations. The two cases with EB had severe dysphagia. Clinical examination showed signs of malnutrition, skin blisters and loss of toenails due to EB. They underwent careful fluoroscopic balloon dilation with 10- and 16-mm-sized balloon catheters, respectively. They could ingest soft and some solid foods after the procedure and maintained during the 20 months and 16 months follow-up periods.

Balloon dilation of epidermolysis bullosa-related esophageal strictures: A report of two cases

Wei-Zhong Zhou,Jing-Guo Xia,Zheng-Qiang Yang,Chun-Gao Zhou,Lin-Bo Zhao,Sheng Liu,Hai Bin Shi 소화기인터벤션의학회 2018 Gastrointestinal Intervention Vol.7 No.3

Epidermolysis bullosa (EB) is a very rare inherited disease featured with skin blistering resulting from minor trauma. Sometimes the esophageal mucosa could also be involved, which leads to esophageal strictures. Here we report two cases of EB-related esophageal strictures who were successfully treated with esophageal balloon dilations. The two cases with EB had severe dysphagia. Clinical examination showed signs of malnutrition, skin blisters and loss of toenails due to EB. They underwent careful fluoroscopic balloon dilation with 10- and 16-mm-sized balloon catheters, respectively. They could ingest soft and some solid foods after the procedure and maintained during the 20 months and 16 months follow-up periods.

2-D meso-scale complex fracture modeling of concrete with embedded cohesive elements

Mingyan Shen,Zheng Shi,Chao Zhao,Xingu Zhong,Bo Liu,Xiaojuan Shu 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.24 No.3

This paper has presented an effective and accurate meso-scale finite element model for simulating the fracture process of concrete under compression-shear loading. In the proposed model, concrete is parted into four important phases: aggregates, cement matrix, interfacial transition zone (ITZ), and the initial defects. Aggregate particles were modelled as randomly distributed polygons with a varying size according to the sieve curve developed by Fuller and Thompson. With regard to initial defects, only voids are considered. Cohesive elements with zero thickness are inserted into the initial mesh of cement matrix and along the interface between aggregate and cement matrix to simulate the cracking process of concrete. The constitutive model provided by ABAQUS is modified based on Wang’s experiment and used to describe the failure behaviour of cohesive elements. User defined programs for aggregate delivery, cohesive element insertion and modified facture constitutive model are developed based on Python language, and embedded into the commercial FEM package ABAQUS. The effectiveness and accuracy of the proposed model are firstly identified by comparing the numerical results with the experimental ones, and then it is used to investigate the effect of meso-structure on the macro behavior of concrete. The shear strength of concrete under different pressures is also involved in this study, which could provide a reference for the macroscopic simulation of concrete component under shear force.

Percutaneous radiologic gastrostomy in patients with amyotrophic lateral sclerosis: A safe and effective technique

Chen Xu,Zheng-Qiang Yang,Sheng Liu,Wei Yang,Hai-Bin Shi,Wei-Zhong Zhou 소화기인터벤션의학회 2021 International journal of gastrointestinal interven Vol.10 No.2

Background: Percutaneous radiologic gastrostomy (PRG) was considered as an alternative technique for long-term enteral nutrition, and the current study is aimed to evaluate the feasibility and safety of this technique in patients with amyotrophic lateral sclerosis (ALS) at a single medical center. Methods: From July 2017 to October 2020, a total of 14 patients underwent PRG with ALS were included in this retrospective study with a median age of 64.0 years, and 78.6% were male. The procedure comprised a dilation of the stomach via a nasogastric catheter, followed by puncture and gastrostomy tube placement under fluoroscopic guidance. The technical success rate and clinical outcomes were recorded over 3 months following the procedure. Results: The technical success rate was 100%. During the follow-up period, minor complications were reported in 2 of patients (14.3%) including superficial skin infection and early tube block. Neither major complications nor mortality were observed. Body mass index of the patients increased significantly from 16.4 ± 2.1 kg/m2 to 17.1 ± 2.0 kg/m2 (t = –13.77; P < 0.001), and the albumin level increased significantly from 37.5 ± 2.3 g/L to 41.8 ± 1.6 g/L (t = –8.82, P < 0.001). Conclusion: PRG is a relatively safe and effective method for ALS patients, and deserves widespread clinical acceptance.

Design and Implementation of a Universal System Control Strategy Applicable to VSC-HVDC Systems

Zhao, Yue,Shi, Li-bao,Ni, Yi-xin,Xu, Zheng,Yao, Liang-zhong The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.1

This paper proposes a universal system control strategy for voltage source converter (VSC) based high voltage direct current (HVDC) systems. The framework of the designed control strategy consists of five layer structures considering the topology and control characteristics of the VSC-HVDC system. The control commands sent from the topmost layer can be transmitted to the next layer based on the existing communication system. When the commands are sent to each substation, the following transmission of commands between the four lower layers are realized using the internal communication system while ignoring the communication delay. This hierarchical control strategy can be easily applied to any VSC-HVDC system with any topology. Furthermore, an integrated controller for each converter is designed and implemented considering all of the possible operating states. The modular-designed integrated controller makes it quite easy to extend its operating states if necessary, and it is available for any kind of VSC. A detailed model of a VSC-HVDC system containing a DC hub is built in the PSCAD/EMTDC environment. Simulation results based on three operating conditions (the start-up process, the voltage margin control method and the master-slave control method) demonstrate the flexibility and validity of the proposed control strategy.

Collapse-resistant performance of a single-story frame assembly and multi-story sub-frame under an internal column-removal scenario

Wei-hui Zhong,Zheng Tan,Li-Min Tian,Bao Meng,Yu-hui Zheng,Shi-chao Daun 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.41 No.5

To elucidate the differences in the collapse behavior between a single-story beam-column assembly and multi-story frame, two 1/3-scale two-bay composite frames, including a single-story composite beam–column assembly and a three-story composite sub-frame, were designed and quasi-statically tested. The load–displacement responses, failure modes, and internal force development of the two frames were analyzed and compared in detail. Furthermore, the resistance mechanisms of the two specimens were explored, and the respective contributions of different load-resisting mechanisms to the total resistances were quantitatively separated to gain deeper insights. The experimental tests indicated that Vierendeel action was present in the two-dimensional multi-story frames, which led to an uneven internal force distribution among the three stories. The collapse resistance of TSDWA-3S in the flexural stage was not significantly increased by the structural redundancy provided by the additional story, as compared to that of TSDWA-1S. Although the development of the load response was similar in the two specimens at flexural stage, the collapse mechanisms of the multi-story composite frame were much more complicated than those of the single-story beam–column assembly, and the combined action between stories was critical in determining the internal force redistribution and rebalancing of the remaining structure.

Percutaneous radiologic gastrostomy in patients with amyotrophic lateral sclerosis: A safe and effective technique

Chen Xu,Zheng-Qiang Yang,Sheng Liu,Wei Yang,Hai-Bin Shi,Wei-Zhong Zhou 소화기인터벤션의학회 2021 Gastrointestinal Intervention Vol.10 No.2

Background: Percutaneous radiologic gastrostomy (PRG) was considered as an alternative technique for long-term enteral nutrition, and the current study is aimed to evaluate the feasibility and safety of this technique in patients with amyotrophic lateral sclerosis (ALS) at a single medical center. Methods: From July 2017 to October 2020, a total of 14 patients underwent PRG with ALS were included in this retrospective study with a median age of 64.0 years, and 78.6% were male. The procedure comprised a dilation of the stomach via a nasogastric catheter, followed by puncture and gastrostomy tube placement under fluoroscopic guidance. The technical success rate and clinical outcomes were recorded over 3 months following the procedure. Results: The technical success rate was 100%. During the follow-up period, minor complications were reported in 2 of patients (14.3%) including superficial skin infection and early tube block. Neither major complications nor mortality were observed. Body mass index of the patients increased significantly from 16.4 ± 2.1 kg/m2 to 17.1 ± 2.0 kg/m2 (t = –13.77; P < 0.001), and the albumin level increased significantly from 37.5 ± 2.3 g/L to 41.8 ± 1.6 g/L (t = –8.82, P < 0.001). Conclusion: PRG is a relatively safe and effective method for ALS patients, and deserves widespread clinical acceptance.

Design and Implementation of a Universal System Control Strategy Applicable to VSC-HVDC Systems

Yue Zhao,Libao Shi,Yixin Ni,Zheng Xu,Liang-Zhong Yao 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.1

This paper proposes a universal system control strategy for voltage source converter (VSC) based high voltage direct current (HVDC) systems. The framework of the designed control strategy consists of five layer structures considering the topology and control characteristics of the VSC-HVDC system. The control commands sent from the topmost layer can be transmitted to the next layer based on the existing communication system. When the commands are sent to each substation, the following transmission of commands between the four lower layers are realized using the internal communication system while ignoring the communication delay. This hierarchical control strategy can be easily applied to any VSC-HVDC system with any topology. Furthermore, an integrated controller for each converter is designed and implemented considering all of the possible operating states. The modular-designed integrated controller makes it quite easy to extend its operating states if necessary, and it is available for any kind of VSC. A detailed model of a VSC-HVDC system containing a DC hub is built in the PSCAD/EMTDC environment. Simulation results based on three operating conditions (the start-up process, the voltage margin control method and the master-slave control method) demonstrate the flexibility and validity of the proposed control strategy.