Experimental Studies on Progressive Collapse Behavior of RC Frame Structures: Advances and Future Needs

Wei?Jian Yi,Fan Yi,Yun Zhou 한국콘크리트학회 2021 International Journal of Concrete Structures and M Vol.15 No.4

In the recent two decades, the progressive collapse of reinforced concrete (RC) frame structures attracted unprecedented research interests in the structural engineering community. Experiments are regarded as an essential method in this field since actual cases can barely provide sufficient and effective data to support rigorous research. In this paper, prevailing experimental assumptions and configurations among over 100 series of experiments are quantitatively revealed by a bibliometric collection based on systematic search in an academic database. Since numerous experiments have been reported on the progressive collapse of RC frame structures, this paper subsequently presents a state-of-the-art review summarizing both experimental consensuses and controversies constituted by three main aspects: (a) static mechanisms, (b) dynamic behavior, and (c) threat-dependent research. The significance of secondary mechanisms, existing problems of dynamic effects, and potential flaws of the threat-independent assumption are discussed in detail with experimental findings. Future needs are emphasized on research targets, correlations between experiments and design, dynamic effects, threat-dependent issues, and retrofitting. These recommendations might help researchers or designers realize a more reliable and realistic progressive collapse design of RC frame structures in the future.

The Religious Belief of Chinese Yi People Embodied in Bimo Culture

웨이이 ( Wei Yi ) 한국동양예술학회 2020 동양예술 Vol.49 No.-

이 논문은 중국 이족 집단에 대한 종교 신앙 체계의 변천과 재구성의 단초인 原初性과 再生性을 연구한다. 이족의 문화는 비교적 안정된 전통을 가지고 있으면서도 시대와 지역, 장르별로 차이가 있다. 이 논문에서 언급하고자 하는 변화는 정상적인 역사와 문화의 법칙 속에서 발전한 것으로, 예를 들어 물과 같은 재생적인 성질을 통해 얻을 수 있는 자연의 생리변화의 이치와 상통하는 점이 있다. 한 지역의 문화도 전승에서 재구성되는 것이 자연의 섭리이자, 이족문화의 종교 신앙 체계 역시 그 예라 할 수 있겠다. 이족의 종교는 지역과 교통이 발달하지 않은 이유로 역사적으로는 비교적 안정된 집단적 형태를 지녔지만, 이러한 안정된 집단 형태도 끊임없이 자기변화와 외래 문화 흡수를 통해 이족 고유의 색채를 보완해 왔다. 따라서 이 논문은 중국 이족의 전통인 畢摩文化에 대한 연구를 통해 이족의 종교문화를 이론적으로 정확하게 인식할 수 있도록 도와주고, 소수민족 문화의 가치를 이해하게 해준다. Through exploration of the memory of Chinese Yi ethnic group, this paper expounds the change and reconstruction of Yi religious belief system from the historical dimension, and studies its "primitive" and "regenerative" natures. Yi culture has its stable tradition, and shows different changes in different times, geographies and scenarios. The author believes that the above changes occur and develop in a normal historical and cultural frame. A "regenerative" evolution also exists, which is similar to the source of water. If no fresh water pours in, it cannot form a river, and may even dry up. All cultures regenerate and reconstruct themselves according to natural law, and the religious belief system in Yi culture is of no exception, and such changes and reconstruction are consistent with the living practice of ethnic groups. Due to geographical and traffic reasons, Yi religious belief remains steady in its form in history, but it is also gradually improved during continuous self-transformation and absorption of foreign culture. Through study of traditional Bimo culture of Yi people in China, this paper can help readers to understand Yi religious culture and its values from a theoretical perspective.

Fault Diagnosis of Marine Turbocharger System Based on an Unsupervised Algorithm

Yi Wei,Hailong Liu,Gengxuan Chen,Jiawei Ye 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.3

The fault diagnosis of a marine turbocharger system is very crucial for realizing intelligent operation and maintenance in a big data analysis context. In order to improve the diagnostic rate of faults in engineering applications, in this paper, a new unsupervised machine learning algorithm, which is based on one-class support vector machine (OSVM), afnity propagation (AP) and Gaussian mixture model (GMM), called OAGFD is proposed for fault diagnosis. OSVM was frstly used to divide samples of marine turbocharger system into normal and fault samples, and only the fault samples are used in following steps to identify specifc fault types. The AP was adopted automatically to provide an initial value for expectation maximization, which can obtain the maximum value of iteration parameters. The GMM is used to classify faults of marine turbocharger system and output the fault diagnosis results. Finally, the OAGFD is validated by actual data. The experiment results show that OAGFD can quickly and accurately be trained. The OAGFD method can achieve higher identifcation accuracy for multi-faults of marine turbocharger system and takes on faster operation speed and stronger generalization ability than tradition methods. It is an efcient and unsupervised fault diagnosis technique and has both theoretical and practical value. This research provides a new method for automatic fault diagnosis of the marine turbocharger system.

Research on the Choice of Knowledge Trading Pattern among Enterprises in Online Innovation Environment

Yi Li,Yuanjie Ni,Wei Liu,Wenxing Yan 보안공학연구지원센터(IJUNESST) 2015 International Journal of u- and e- Service, Scienc Vol.8 No.1

In the network innovation environment, the knowledge trading between enterprises could be divided into traditional pattern (TP) and the E-commerce pattern (ECP). The two both have their advantages and disadvantages, so enterprises would face the problem. This paper generalizes the operation characteristics and the influence factors of two patterns. The mathematical model is used to analyze the selection mechanism of choosing two patterns, and the result illustrated that when the agency fee, the risk cost of ECP and the trading potential get bigger, the possibility that enterprises choose TP would get bigger, too; and when the explicitness of knowledge, cost of searching, trading incentive, the risk cost of TP and the reserve cost of ECP increase, the possibility that enterprises choose ECP would increase. When the reserve cost of ECP becomes big enough, it would make enterprises be more willing to choose hybrid pattern.

Comparison of thoracotomy and thoracoscopic surgery for non-small cell carcinoma of the lung: longitudinal study

Yi-Wei Chen,Tsae -Jyy Wang 한국간호과학회 2023 한국간호과학회 학술대회 Vol.2023 No.11

A vision-based system for long-distance remote monitoring of dynamic displacement: experimental verification on a supertall structure

Yi-Qing Ni,You-Wu Wang,Wei-Yang Liao,Wei-Huan Chen 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.6

Dynamic displacement response of civil structures is an important index for in-construction and in-service structural condition assessment. However, accurately measuring the displacement of large-scale civil structures such as high-rise buildings still remains as a challenging task. In order to cope with this problem, a vision-based system with the use of industrial digital camera and image processing has been developed for long-distance, remote, and real-time monitoring of dynamic displacement of supertall structures. Instead of acquiring image signals, the proposed system traces only the coordinates of the target points, therefore enabling real-time monitoring and display of displacement responses in a relatively high sampling rate. This study addresses the in-situ experimental verification of the developed vision-based system on the Canton Tower of 600 m high. To facilitate the verification, a GPS system is used to calibrate/verify the structural displacement responses measured by the vision-based system. Meanwhile, an accelerometer deployed in the vicinity of the target point also provides frequency-domain information for comparison. Special attention has been given on understanding the influence of the surrounding light on the monitoring results. For this purpose, the experimental tests are conducted in daytime and nighttime through placing the vision-based system outside the tower (in a brilliant environment) and inside the tower (in a dark environment), respectively. The results indicate that the displacement response time histories monitored by the vision-based system not only match well with those acquired by the GPS receiver, but also have higher fidelity and are less noise-corrupted. In addition, the low-order modal frequencies of the building identified with use of the data obtained from the vision-based system are all in good agreement with those obtained from the accelerometer, the GPS receiver and an elaborate finite element model. Especially, the vision-based system placed at the bottom of the enclosed elevator shaft offers better monitoring data compared with the system placed outside the tower. Based on a wavelet filtering technique, the displacement response time histories obtained by the vision-based system are easily decomposed into two parts: a quasi-static ingredient primarily resulting from temperature variation and a dynamic component mainly caused by fluctuating wind load.

Maneuvering Target Tracking Using LOS and Fuzzy Input Estimator

Yi-Wei Chen,Ken-Ming Tu 한국항공우주학회 2018 International Journal of Aeronautical and Space Sc Vol.19 No.4

The performance of maneuvering target tracking relies on the extraction of useful information about the target state from the observations, and the key factors focus on the suitable target models and the filters. A usable maneuvering target tracking technique is proposed in this paper. The line-of-sight (LOS) dynamic equations of interceptor–target are modified for the target model and the azimuth angle, elevation angle and the relative range between the radar and the target can be detected by the radar system fixed on the ground. A fuzzy input estimator based on Kalman filter and input estimation method is developed in which the fuzzy logic theory is used to accelerate the estimator tracking speed to the signal input. Three different filters are used to combine with the modified LOS target model for the verification and comparison. Besides, the proposed algorithm is compared with two different target tracking techniques. Simulation results prove the modified LOS target model is practical and the developed fuzzy input estimator can increase the estimation precision. The proposed algorithm has the least estimation error of target position compared with the other two different target tracking techniques.

Bone Morphogenetic Protein-2 Sustained Delivery by Hydrogels with Microspheres Repairs Rabbit Mandibular Defects

Wei-Yi Song,Guo-Min Liu,Juan Li,Yun-Gang Luo 한국조직공학과 재생의학회 2016 조직공학과 재생의학 Vol.13 No.6

Mandible defect is a difficult issue in dental surgery owing to limited therapeutic options. Recombinant human bone morphogenetic protein-2 (rhBMP2) is osteoinductive in bone regeneration. This article prepared chitosan/collagen hydrogels with rhBMP2-incorporated gelatin microsphere (GMs) for a sustained release of rhBMP2 to induce bone regeneration in rabbits. In experiments, mandibular defects of 8 mm in diameter and 3 mm in depth were surgically prepared on the right cheek of 27 rabbits. Either chitosan/collagen hydrogels alone, rhBMP2-incorporated hydrogels, or hydrogels with rhBMP2-incorporated GMs were implanted to the defect sites. The animals were euthanized at 2, 6, 12 weeks following surgery. In results, scanning electronic microscope images revealled spherical GMs. The complex delivery systems, hydrogels with rhBMP2-incorporated GMs, exhibited ideal release profiles in vitro. The complex delivery systems resulted in apparent new bone formation within 12 weeks, as evidenced by computed tomography and histological observations. All these results demonstrated that the chitosan/collagen hydrogels with rhBMP2-incorporated GMs had a better capacity to heal mandible defects than other two hydrogel scaffolds. Chitosan/collagen hydrogels with rhBMP2-incorporated GMs might be potential carriers of rhBMP2 for accelerating the repair of mandibular defects.

TC1 (C8orf4) is involved in ERK1/2 pathway-regulated G1-to S-phase transition

( Yi Dong Wang ),( Guo Hui Bian ),( Xiao Yan Lv ),( Rong Zheng ),( Huan Sun ),( Zheng Zhang ),( Ye Chen ),( Qin Wei Li ),( Yan Xiao ),( Qiu Tan Yang ),( Jian Zhong Ai ),( Yu Quan Wei ),( Qin Zhou ) 생화학분자생물학회 2008 BMB Reports Vol.41 No.10

The K+/H+ antiporter AhNHX1 improved tobacco tolerance to NaCl stress by enhancing K+ retention

Wei-Wei Zhang,Jing-Jing Meng,Jin-Yi Xing,Sha Yang,Feng Guo,Xin-Guo Li,Shu-Bo Wan 한국식물학회 2017 Journal of Plant Biology Vol.60 No.3

High salinity is the one of important factors limiting plant growth and crop production. Many NHX-type antiporters have been reported to catalyze K+/H+ exchange to mediate salt stress. This study shows that an NHX gene from Arachis hypogaea L. has an important role in K+ uptake and transport, which affects K+ accumulation and plant salt tolerance. When overexpressing AhNHX1, the growth of tobacco seedlings is improved with longer roots and a higher fresh weight than the wild type (WT) under NaCl treatment. Meanwhile, when exposed to NaCl stress, the transgenic seedlings had higher K+/H+ antiporter activity and their roots got more K+ uptake. NaCl stress could induce higher K+ accumulation in the roots, stems, and leaves of transgenic tobacco seedlings but not Na+ accumulation, thus, leading to a higher K+/Na+ ratio in the transgenic seedlings. Additionally, the AKT1, HAK1, SKOR, and KEA genes, which are involved in K+ uptake or transport, were induced by NaCl stress and kept higher expression levels in transgenic seedlings than in WT seedlings. The H+-ATPase and H+-PPase activities were also higher in transgenic seedlings than in the WT seedlings under NaCl stress. Simultaneously, overexpression of AhNHX1 increased the relative distribution of K+ in the aerial parts of the seedlings under NaCl stress. These results showed that AhNHX1 catalyzed the K+/H+ antiporter and enhanced tobacco tolerance to salt stress by increasing K+ uptake and transport.