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.

Dynamic simulation and control of a triple column process for dimethyl carbonate- methanol separation

Hong-Mei Wei,Qiang Gao,Wei-zhou Jiao,Wei Wei 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.12

Separation of dimethyl carbonate/methanol azeotropic mixture by using pressure-swing distillation processhas been a hot-point in the study of the synthesis process of dimethyl carbonate by urea methanolysis method. Thisstudy updates the work of the writers (Ind.Eng.Chem.Res,2013,52,11463-11478), which explores the dynamic controlstructure of the three-column separation dimethyl carbonate (DMC)/methanol (MeOH) process from an actual pilotplant. At first, the conventional DMC/MeOH separation process in the pilot test of the DMC synthesis process throughalcoholysis of urea was described in detail. Then an optimized control structure for the entire DMC/MeOH separationunit was obtained by implementing a general heuristic design procedure. An economic analysis was performed to evaluatethe optimized process. Finally, three dynamic control schemes were proposed and evaluated with several large disturbances,an improved control scheme CS3, using the multiplier blocks “QR1/F1” and “RR1” in T1, “QR1/F1” and “R/F”in both T2 and T3, outperformed CS1 and CS2 by maintaining the product specification in each column.

CONJUGACY SEPARABILITY OF GENERALIZED FREE PRODUCTS OF FINITELY GENERATED NILPOTENT GROUPS

Zhou, Wei,Kim, Goan-Su,Shi, Wujie,Tang, C.Y. Korean Mathematical Society 2010 대한수학회보 Vol.47 No.6

In this paper, we prove a criterion of conjugacy separability of generalized free products of polycyclic-by-finite groups with a non cyclic amalgamated subgroup. Applying this criterion, we prove that certain generalized free products of polycyclic-by-finite groups are conjugacy separable.

Conjugating Automorphisms of Certain Hnn Extensions

Wei Zhou,김관수 영남수학회 2020 East Asian mathematical journal Vol.36 No.3

WeconsiderHNNextensions⟨B,t:t−1Ht=K⟩,whereH,K are in the center of B. We show that conjugating automorphisms of those HNN extensions are inner if B satisfies certain conditions.

Language Attitude of Ethnic Chinese in Four Southeast Asian Countries

Wei Zhou,Jun-Eon Park 한국외국어교육학회 2017 Foreign languages education Vol.24 No.3

Today, tens of millions of ethnic Chinese are scattered throughout Southeast Asia as a result of the massive influx of immigrants from China during the past several centuries. The present study analyzed the language attitude of the ethnic Chinese in Southeast Asia, focusing on four countries: Indonesia, Thailand, Malaysia, and Singapore. For this purpose, a total of 177 samples of language attitude questionnaire were collated. The questionnaire was composed of 11 language attitude-related elements in affective, behavioral, and cognitive components with respect to the multiple languages used in the countries: national language, English, local Chinese dialects, Mandarin, and others. Analysis of the data reveals intriguing findings about the language attitude of the ethnic Chinese in different countries. Both the similarities and the differences of language attitude are found among the ethnic Chinese groups in the Southeast Asian countries, reflecting the political, economic, and social situations of each country. The prospect of the local Chinese dialects look dim due to exogenous factors surrounding the linguistic ecosystems in the region.

New metabolites from the biotransformation of ginsenoside Rb1 by Paecilomyces bainier sp.229 and activities in inducing osteogenic differentiation by Wnt/β-catenin signaling activation

Zhou, Wei,Huang, Hai,Zhu, Haiyan,Zhou, Pei,Shi, Xunlong The Korean Society of Ginseng 2018 Journal of Ginseng Research Vol.42 No.2

Background: Ginseng is a well-known traditional Chinese medicine that has been widely used in a range of therapeutic and healthcare applications in East Asian countries. Microbial transformation is regarded as an effective and useful technology in modification of nature products for finding new chemical derivatives with potent bioactivities. In this study, three minor derivatives of ginsenoside compound K were isolated and the inducing effects in the Wingless-type MMTV integration site (Wnt) signaling pathway were also investigated. Methods: New compounds were purified from scale-up fermentation of ginsenoside Rb1 by Paecilomyces bainier sp. 229 through repeated silica gel column chromatography and high pressure liquid chromatography. Their structures were determined based on spectral data and X-ray diffraction. The inductive activities of these compounds on the Wnt signaling pathway were conducted on MC3T3-E1 cells by quantitative real-time polymerase chain reaction analysis. Results: The structures of a known 3-keto derivative and two new dehydrogenated metabolites were elucidated. The crystal structure of the 3-keto derivative was reported for the first time and its conformation was compared with that of ginsenoside compound K. The inductive effects of these compounds on osteogenic differentiation by activating the Wnt/b-catenin signaling pathway were explained for the first time. Conclusion: This study may provide a new insight into the metabolic pathway of ginsenoside by microbial transformation. In addition, the results might provide a reasonable explanation for the activity of ginseng in treating osteoporosis and supply good monomer ginsenoside resources for nutraceutical or pharmaceutical development.

Comparative Study between ZOOMit and Conventional Intravoxel Incoherent Motion MRI for Assessing Parotid Gland Abnormalities in Patients with Early- or Mid-Stage Sjögren’s Syndrome

Zhou Qing-Qing,Zhang Wei,Yu Yu-Sheng,Li Hong-Yan,Wei Liang,Li Xue-Song,He Zhen-Zhen,Zhang Hong 대한영상의학회 2022 Korean Journal of Radiology Vol.23 No.4

Objective: To compare the reproducibility and performance of quantitative metrics between ZOOMit and conventional intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) in the diagnosis of early- and mid-stage Sjögren’s syndrome (SS). Materials and Methods: Twenty-two patients (mean age ± standard deviation, 52.0 ± 10.8 years; male:female, 2:20) with early- or mid-stage SS and 20 healthy controls (46.9 ± 14.6 years; male:female, 7:13) were prospectively enrolled in our study. ZOOMit IVIM and conventional IVIM MRI were performed simultaneously in all individuals using a 3T scanner. Quantitative IVIM parameters - including tissue diffusivity (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) - inter- and intra-observer reproducibility in measuring these parameters, and their ability to distinguish patients with SS from healthy individuals were assessed and compared between ZOOMit IVIM and conventional IVIM methods, appropriately. MR gland nodular grade (MRG) was also examined. Results: Inter- and intra-observer reproducibility was better with ZOOMit imaging than with conventional IVIM imaging (ZOOMit vs. conventional, intraclass correlation coefficient of 0.897–0.941 vs. 0.667–0.782 for inter-observer reproducibility and 0.891–0.968 vs. 0.814–0.853 for intra-observer reproducibility). Significant differences in ZOOMit f, ZOOMit D*, conventional D*, and MRG between patients with SS and healthy individuals (all p < 0.05) were observed. ZOOMit D* outperformed conventional D* in diagnosing early- and mid-stage SS (area under receiver operating curve, 0.867 and 0.658, respectively; p = 0.002). The combination of ZOOMit D*, MRG, and ZOOMit f as a new diagnostic index for SS, increased diagnostic area under the curve to 0.961, which was higher than that of any single parameter (all p < 0.01). Conclusion: Considering its better reproducibility and performance, ZOOMit IVIM may be preferred over conventional IVIM MRI, and may subsequently improve the ability to diagnose early- and mid-stage SS.

An Interference Isolation Method for Wireless Power and Signal Parallel Transmissions on CPT Systems

Wei Zhou,Yu-Gang Su,Shi-Yun Xie,Long Chen,Xin Dai,Yu-Ming Zhao 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.1

A novel interference isolation method is proposed by using several designed coils in capacitive power transfer systems as isolation impedances. For each designed coil, its stray parameters such as the inter-turn capacitance, coil resistance and capacitance between the coil and the core, etc. are taken into account. An equivalent circuit model of the designed coil is established. According to this equivalent circuit, the impedance characteristic of the coil is calculated. In addition, the maximum impedance point and the corresponding excitation frequency of the coil are obtained. Based on this analysis, six designed coils are adopted to isolate the interference from power delivery. The proposed method is verified through experiments with a power carrier frequency of 1MHz and a data carrier frequency of 8.7MHz. The power and data are transferred parrallelly with a data carrier attenuation lower than -5dB and a power attenuation on the sensing resistor higher than -45dB.

Abelian subgroup separability of certain HNN extensions

Zhou, Wei,Kim, Goansu World Scientific Publishing Company 2018 International journal of algebra and computation Vol.28 No.3

<P>In this paper, we prove that certain HNN extensions of finitely generated abelian subgroup separable groups are finitely generated abelian subgroup separable. Using this, we show that certain HNN extensions of finitely generated nilpotent groups are finitely generated abelian subgroup separable.</P>

Phytochemical Studies of Korean Endangered Plants: A New Flavone from Rhododendron brachycarpum G.Don

Wei Zhou,오준석,이위,김동우,이승호,나민균 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.8