Amplitude dependency of damping of tall structures by the random decrement technique

An Xu,Zhuangning Xie,Ming Gu,Jiurong Wu 한국풍공학회 2015 Wind and Structures, An International Journal (WAS Vol.21 No.2

This study focuses on the amplitude dependency of damping of tall structures by the random decrement technique (RDT). Many researchers have adopted RDT to establish the amplitude dependency of damping ratios in super-tall buildings under strong wind loads. In this study, a series of simulated examples were analyzed to examine the reliability of this method. Results show that damping ratios increase as vibration amplitudes increase in several cases; however, the damping ratios in the simulated signals were preset as constants. This finding reveals that this method and the derived amplitude-dependent damping ratio characteristics are unreliable. Moreover, this method would obviously yield misleading results if the simulated signals contain Gaussian white noise. Full-scale measurements on a super-tall building were conducted during four typhoons, and the recorded data were analyzed to observe the amplitude dependency of damping ratio. Relatively wide scatter is observed in the resulting damping ratios, and the damping ratios do not appear to have an obvious nonlinear relationship with vibration amplitude. Numerical simulation and field measurement results indicate that the widely-used method for establishing the amplitude-dependent damping characteristics of super-tall buildings and the conclusions derived from it might be questionable at the least. More field-measured data must be collected under strong wind loads, and the damping characteristics of super-tall buildings should be investigated further.

중국조선족집거구문제에 대한 사고

허명철 전남대학교 아시아태평양지역연구소 2000 아시아태평양지역연구 Vol.3 No.1

21세기 새로운 민족적 비전을 꿈꾸고 있는 중국조선족사회는 현재 인구감소와 인구류동에 의한 기존의 집거구해체와 이에 따라 나타나고 있는 사회성적인 문제들로 하여 고민을 겪고 있다. 집거구해체는 민족교육의 위기를 초래하게 되고 민족언어와 문자를 사용할 수 있는 문화공간을 좁아지게 하는바 이는 결국 민족동화를 가속화하게 되며 나중에는 민족정체성 유지에도 큰 영향을 미치게 된다는 것이 일부 학자들의 주장이다. 그렇다면 집거구해체를 어떤 입장에서 평가해야 하고 이에 따라 초래되고 있는 문제들은 또 어떤 시각에서 풀어나가야 하는가? 이 문제어 대해서 우리는 기존의 집거구가 형성되고 보존되어 올 수 있었던 원인들을 검토해 보고 그 기초상에서 응당 시대성, 민족성, 발전성적인 시각에서 그 답안을 모색해야 한다. 여기에서 우선 중요한 것은 우리들의 의식전환이다. 오늘날 우리민족의 진로는 농촌에 있는 것이 아니라 도시어 있으며 현대문명에로의 이행에 있는 것이다. 우리는 연해개방도시들에 새로 일떠서고 있는 새로운 집거지 즉 "코리아타운'에 민족의 미래를 기탁하고 기존의 농촌집거구건설을 잘하여 질적으로 제고시키는 한편 보다 많은 정력을 도시집거구건설에 몰부어야 하고 새로운 집거구형성과정에서 나타나고 있는 산재지구에서의 민족교육실시, 민족문자와 언어보급, 민족정체성 보존등 문제들의 해결에 주력해야 한다. 그러고 이러한 문제점 해결에 있어서 그 시야를 보다 넓혀 세계화적 추세와 정보화문명에 입각점을 두어야 한다. In the 21st century, the Chinese-Korean(Korean minority in china) who are striving for a leap in their ethnical improvement is now vexed by population decline and migration which are disintegrating the old Chinese-Korean community. Some scholars believe that the disintegration of Chinese-Korean community will lead to a series of problems: a crisis of ethnic education, a reduction of the cultural space where the Chinese-Koreans can learn and use their language, ethic assimilation, and consequently disintegration of Chinese-Korean community. How can we solve the Problem on the disintegration of Chinese-Korean community? We should reconsider the reasons why Chinese-Korean community can de formed and developed. In addition to that, We should seek the answer to this problem from the perspective of time, ethology and development. thus, the development of Chinese-Korean. The approach towards the development of Chinese-Korean does not rely on the rural area, but on the more developed and civalized urban area.. the future of the Chinese-Korean lies on the "Korean Town", i · e · the new Chinese-Korean communities in the new opening cities along the east coast line of China. In addition to improve the qualits of the old Chinese-Korean communities which mainly inhabited in the hew Chinese-Korean communities which considerately live in the urban cities. During the course of the formation of the hew Chinese-Korean communities in the eastern urban area of China, we should put great effort on the ethnic education, popularization of Korean language, and maintenance of the integrity of the Chinese-Korean community. Furthermore, we should enlarge our perspective and focus our attention at the trends of globalization and informationalized civilization in the world.

Distinctions Between Clinicopathological Factors and Prognosis of Alpha-fetoprotein Negative and Positive Hepatocelluar Carcinoma Patients

Xu, Jia,Liu, Chang,Zhou, Lei,Tian, Feng,Tai, Ming-Hui,Wei, Ji-Chao,Qu, Kai,Meng, Fan-Di,Zhang, Ling-Qiang,Wang, Zhi-Xin,Zhang, Jing-Yao,Chang, Hu-Lin,Liu, Si-Nan,Xu, Xin-Shen,Song, Yan-Zhou,Liu, Jun,Z Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.2

Serum alpha-fetoprotein (AFP) is a significant marker for clinical diagnosis and prognosis evaluation in hepatocellular carcinoma (HCC) patients. However, some proportion of liver cancer patients are AFP-negative (AFP ${\leq}$20ng/ml). In order to study the differences between clinicopathological factors and prognosis of alpha-fetoprotein negative and positive patients, a total of 114 cases (41 AFP-negative and 73 AFP-positive) were selected for our research. By systematically statistical analysis, the results demonstrated that compared with AFP-negative patients, AFP-positive examples were more likely to feature cirrhosis nodules, non-complete neoplasm capsules, and a poor Edmondson-steiner grade. Furthermore, AFP-negative patients demonstrated a favorable long-term prognosis. By univariate analysis and multivariate analysis with Cox's proportional hazards model, multiple tumors were found to be independent risk factors for worse survival of AFP negative patients; however, less tumor-free margins, multiple tumors and Edmondson-steiner grades III/IV, proved to be independent risk factors leading to a poor prognosis of AFP positive cases. Finally, we can infer that high levels of AFP signify a highly malignant tumor and unfavorable prognosis.

Expression and Significance of Microsomal Prostaglandin Synthase-1 (mPGES-1) and Beclin-1 in the Development of Prostate Cancer

Xu, Lu-Wei,Qian, Ming,Jia, Rui-Peng,Xu, Zheng,Wu, Jian-Ping,Li, Wen-Cheng,Huang, Wen-Bin,Chen, Xing-Guo Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

The aim of this study was to investigate the expression and significance of microsomal prostaglandin synthase-1 (mPGES-1) and Beclin-1 in the development of prostate cancer (PCa). Immunohistochemistry was performed on paraffin-embedded sections with rabbit polyclonal against mPGES-1 and Beclin-1 in 40 PCa, 40 benign prostatic hyperplasia (BPH) and 10 normal prostate specimens for this purpose. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied for mRNA expression of mPGES-1 and Beclin-1, while MTT assays were used to ascertain the best working concentration of the mPGES-1 inhibitor (CAY10526). The effect of CAY10526 treatment on expression of Beclin-1 in DU-145 cells was studied using Western blot analysis. Localization of Beclin-1 and mPGES-1 was in endochylema. Significant differences in expression was noted among PCa, BPH and normal issues (P<0.05). Beclin-1 expression inversely correlated with mPGES-1 expression in PCa tissue (P<0.05). CAY10526 could significantly block mPGES-1 expression and the proliferation of DU-145 cells (P<0.05), while increasing Beclin-1 levels (P<0.05). Overexpression of mPGES-1 could decrease the autophagic PCa cell death. Inhibiting the expression of mPGES-1 may lead to DU-145 cell death and up-regulation of Beclin-1. The results suggest that inhibition of mPGES-1 may have therapeutic potential for PCa in the future.

UNIQUE POINT OF COINCIDENCE FOR TWO MAPPINGS WITH ϕ- OR ψ-φ-CONTRACTIVE CONDITIONS ON 2-METRIC SPACES

Ming-Xing Xu,Xin Huang,Yong-Jie Piao 충청수학회 2016 충청수학회지 Vol.29 No.3

We discuss and obtain some existence theorems of unique point of coincidence for two mappings satisfying ϕ-contractive conditions or ψ-φ-contractive conditions determined by semi-continuous functions on non-complete 2-metric spaces, in which the mappings do not satisfy commutativity and uniform boundedness. The ob-tained results generalize and improve many well-known and corre-sponding conclusions.

Synthesis and Properties of Exfoliated Poly(methyl methacrylate-co- acrylonitrile)/Clay Nanocomposites via Emulsion Polymerization

Ming Zhe Xu,Yeong Suk Choi,Ki Hyun Wang,Jong Hyun Kim,In Jae Chung 한국고분자학회 2003 Macromolecular Research Vol.11 No.6

Collapse Behaviours of Stiffened Panels Under Longitudinal Compression Considering Heating and Cooling Processes

Ming Cai Xu,Zhao Jun Song,Jin Pan 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.4

The fi re accidents casually happen during operation of ship, which would infl uence the load carrying capacity of stiff ened panel of ship structures due to the thermal load. The present paper aims to understand the infl uence of thermal loads on the collapse behaviour of stiff ened panels under longitudinal compressive load. Considering the heating and cooling down processes, the collapse behaviours of the stiff ened panels under combined in-plane displacement and heat loads representative of fi re accident are simulated in the FE (fi nite element) analysis herein. Firstly, the thermal load is considered to investigate the stress state of the stiff ened panels during heating and cooling processes. It is found that the stiff ened panels would collapse during thermal loads for the structure with large heated zone. After that, the longitudinal compression loads are applied to assess the collapse strength of the stiff ened panels. The parametric studies including diff erent geometrical dimensions and areas of heat zone are performed in detail to quantify the eff ects of heat loads on the collapse behaviours of stiff ened panels. It is found that the expansion could produce biaxial stress state that depends on not only in-plane stiff ness but also collapse modes, and for stiff ened panels with various heated area the cooling down to room temperature induce similar ultimate strength to that without considering heat loads.

Cytotoxic Constituents Isolated from the Fruit Bodies of Hypsizigus marmoreus

Xu, Ming-Lu,Choi, Jae-Young,Jeong, Byeong-Seon,Li, Gao,Lee, Kap-Rang,Lee, Chong-Soon,Woo, Mi-Hee,Lee, Eung-Seok,Jahng, Yurng-Dong,Chang, Hyeun-Wook,Lee, Seung-Ho,Son, Jong-Keun 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.1

The bioactivity-guided fractionation of chloroform extracts of the fruit bodies of Hypsizigus marmoreus led to our isolation of $(22E,24R)-ergosta-7,22-diene-3{\beta},5{\alpha},6{\beta}-triol$ (1), $ergosterol-3-O-{\beta}-D-glucopyranoside$ (2), $5{\alpha},8{\alpha}-epidioxyergosta-6,22-dien-3{\beta}-ol$ (3), hypsiziprenol $A_9$ (4), hypsiziprenol $AA_8$ (5), hypsiziprenol $AA_9$ (6) and hypsiziprenol $BA_{10}$ (7). Among these seven isolates, compound 2 was identified for the first time from this plant. All compounds (1-7) exhibited moderate cytotoxicity towards cultured human colon carcinoma (HT-29), human breast carcinoma (MCF-7) and human hepatoblastoma (HepG-2) cell lines.

Reverse Endoscopic Ultrasound-Guided Gastrojejunostomy for the Treatment of Superior Mesenteric Artery Syndrome: A New Concept

Ming-ming Xu,Enad Dawod,Monica Gaidhane,Amy Tyberg,Michel Kahaleh 대한소화기내시경학회 2020 Clinical Endoscopy Vol.53 No.1

Superior mesenteric artery syndrome (SMAS) causes compression and partial or complete obstruction of the duodenum, resulting inabdominal pain, nausea, vomiting, and weight loss. If conservative therapy fails, the patient is typically referred for enteral feeding orlaparoscopic gastrojejunostomy. The last few years have seen increasing use of endoscopic ultrasound-guided gastrojejunostomy (EUS-GJ) for gastric obstructionindications. EUS-GJ involves the creation of a gastric bypass via an echoendoscope in cases in which the small intestine can bepunctured under ultrasonographic visualization, resulting in an incision-free, effcient, and safe procedure. In this case report, we present the first case of SMAS treated using a reverse EUS-GJ, and describe the steps and advantages of theprocedure in this particular case.

The boundedness of some bilinear singular integral operators on Besov spaces

Ming Xu 대한수학회 2006 대한수학회지 Vol.43 No.2

In this paper we weaken the kernel conditions of bilinear Calder$\acute{o}$n-Zygmund operators and prove boundedness on Besov spaces.