Durability Model of Exposed Concrete On-Site Based on Dual Coupling Factors

Yong Fu,Hongxia Qiao,Chenggong Lu,Theogene Hakuzweyezu,Fei Guo 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.1

Aiming at the problem that the reliability analysis of the outdoor exposed concrete structure under the action of a single factor is not consistent with the actual service environment, a reliability analysis based on the Copula function describing multiple degradation factors is proposed. According to the actual data collected on-site, the relative quality evaluation parameters (RQEP) and relative dynamic elastic modulus evaluation parameters (RDEMEP) was selected as the key degradation indicators, and the Aperture Information Criterion (AIC) was used to determine the optimal marginal distribution function in different degradation trajectories, and obtain the most optimal edge distribution function under a single factor. Optimize the edge distributions reliability curve, establish the relationship between the edge distributions through the Copula function, and couple the edge distributions of the remaining life of the concrete to obtain the joint reliability function of the concrete under the action of the coupling factors. The results show that the selection of two degradation indicators, RQEP and RDEMEP, is helpful in establishing the concrete life prediction model in the field exposure environment, and the RDEMEP are more sensitive to the field exposure environment than the RQEP. The Gumbel Copula distribution function can reasonably predict the reliability of exposed concrete on-site under dual coupling factors. The service life of C40 and C50 exposed concrete on site is about 400 and 550 months, respectively.

Projection methods for relaxed cocoercive variation inequalities in Hilbert spaces

Yongfu Su,HONG ZHANG 한국전산응용수학회 2009 Journal of applied mathematics & informatics Vol.27 No.1

In this paper, we introduce and consider a new system of re- laxed cocoercive variational inequalities involving three different operators and the concept of projective nonexpansive mapping. Base on the pro- jection technique, we suggest two kinds of new iterative methods for the approximate solvability of this system. The results presented in this pa- per extend and improve the main results of [S.S. Chang, H.W.J. Lee, C.K. Chan, Generalized system for relaxed cocoercive variational inequalities in Hilbert spaces, Appl. Math. Lett. 20 (2007) 329-334] and [Z. Huang, M. Aslam Noor, An explicit projection method for a system of nonlinear vari- ational inequalities with different (γ, r)-cocoercive mappings, Appl. Math. Comput. (2007), doi:10.1016/j.amc.2007.01.032]. In this paper, we introduce and consider a new system of re- laxed cocoercive variational inequalities involving three different operators and the concept of projective nonexpansive mapping. Base on the pro- jection technique, we suggest two kinds of new iterative methods for the approximate solvability of this system. The results presented in this pa- per extend and improve the main results of [S.S. Chang, H.W.J. Lee, C.K. Chan, Generalized system for relaxed cocoercive variational inequalities in Hilbert spaces, Appl. Math. Lett. 20 (2007) 329-334] and [Z. Huang, M. Aslam Noor, An explicit projection method for a system of nonlinear vari- ational inequalities with different (γ, r)-cocoercive mappings, Appl. Math. Comput. (2007), doi:10.1016/j.amc.2007.01.032].

Spatial correlation of aerodynamic forces on 5:1 rectangular cylinder in different VIV stages

Yongfu Lei,Yanguo Sun,Tianyi Zhang,Xiongwei Yang,Ming-shui Li 한국풍공학회 2022 Wind and Structures, An International Journal (WAS Vol.34 No.1

To better understand the vortex-induced vibration (VIV) characteristics of a 5:1 rectangular cylinder, the distribution of aerodynamic force and the non-dimensional power spectral density (PSD) of fluctuating pressure on the side surface were studied in different VIV development stages, and their differences in the stationary state and vibration stages were analyzed. The spanwise and streamwise correlations of surface pressures were studied, and the flow field structure partitions on the side surface were defined based on the streamwise correlation analysis. The results show that the variation tendencies of mean and root mean square (RMS) pressure coefficients are similar in different VIV development stages. The RMS values during amplitude growth are larger than those at peak amplitude, and the smallest RMS values are observed in the stationary state. The spanwise correlation coefficients of aerodynamic lifts increase with increase of the peak amplitude. However, for the lock-in region, the maximum spanwise correlation coefficient for aerodynamic lifts occurs in the VIV rising stage rather than in the peak amplitude stage, probably due to the interaction of vortex shedding force (VSF) and self-excited force (SEF). The streamwise correlation results show that the demarcation point positions between the recirculation region and the main vortex region remain almost constant in different VIV development stages, and the reattachment points gradually move to the tailing edge with increasing amplitude. This study provides a reference to estimate the demarcation point and reattachment point positions through streamwise correlation and phase angle analysis from wind tunnel tests.

Development and application of EST-SSR to evaluate the genetic diversity of Southeast Asian rice planthoppers

Yongfu Qiu,Xiaozhen Jiao,Dehui Hu,Fang Liu,Fengkuan Huang,Rongbai Li 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.3

A total of 320 ESTs (Expressed Sequence Tags, 12.8%) of rice planthoppers were identified to carry SSR (Simple Sequence Repeat) motifs from2491 ESTs downloaded frompublic database, and 397 pairs of brown planthopper (BPH; Nilaparvata lugens Stål) and 25 pairs ofwhite-backed planthopper (WBPH; Sogatella furcifera) (Hemiptera: Delphacidae) EST-SSR were detected based on the motifs. The dinucleotide repeat was the dominant type with repeat motif AG/GA/TC/CT; and the trinucleotide repeat was the style of AAG/AGA/GAA/TTC/TCT/CTT among the BPH repeat motifs. A total of 20 EST-SSRs (16 developed in the present study and four fromprevious studies) were applied to survey the genetic diversity of the 15 rice planthoppers. Consequently, 18 pairs of primer amplifies clear, dominant and polymorphic gel bands among the collected planthoppers population; one ESTSSR amplified a single gel band; and one had no result. Furthermore, a total of 227 bands were produced by the selected 19 pairs of primers, of which 207 bands (91.2%) were polymorphic among the test insect populations. Genetic diversity analysis suggested that the BPH populations from Cuu Long, Thailand and Ho Chi Minh were clustered, respectively; and Hue and Long Xuyen were composed into one class; the others were clustered together when the similar coefficient was 0.76. The results show that it is an effective and available approach to develop SSR markers based on ESTs in rice planthoppers; and also the developed EST-SSR markers could detect the genetic diversity of the planthoppers population, which would be beneficial for rice planthoppers control strategy. ©

Polarization State of Scattered Light in Apertureless Reflection-mode Scanning Near-Field Optical Microscopy

Yongfu Cai,Mitsuharu Aoyagi,Akira Emoto,Tatsutoshi Shioda,Takayuki Ishibashi 한국자기학회 2013 Journal of Magnetics Vol.18 No.3

We studied the polarization state in an apertureless scanning near-field microscopy (a-SNOM) operating in reflection mode by using three-dimensional Finite-difference Time-domain (FDTD) method. As a result, the electric field around tip apex in the near-field region enhanced four times stronger than the incident light for ppolarization when the tip-sample separation was 10 nm. We find that the p- and s-polarization state is maintained for the scattered light when the probe is perpendicular to the sample. When the probe is not perpendicular to the sample, the polarization state of scattered light will rotate an angle that equals to the inclination angle of probe with p-polarization illumination. On the other hand, the polarization state will not rotate with s-polarization illumination.

WEAK CONVERGENCE OF MANN ITERATIVE SEQUENCE FOR NONEXPANSIVE MAPPINGS IN PROBABILISTIC HILBERT SPACES

Yongfu Su,Xiuzhen Wang,Junyu Gao 영남수학회 2008 East Asian mathematical journal Vol.24 No.1

The purpose of this paper is to establish the weak convergence theorem of Mann iterative sequence for nonexpansive mappings in probabilistic Hilbert spaces. In order to establish the weak convergence theorem, a new method was presented in this paper, that is method of mathematical expectation.

The Economics of Para-social Interactions During Live Streaming Broadcasts : A Study of Wanghongs

Yongfu Quan,Jin Seon Choe,Il Im 한국경영정보학회 2020 Asia Pacific Journal of Information Systems Vol.30 No.1

Weak and strong convergence to common fixed points of non-self nonexpansive mappings

Yongfu Su,Xiaolong Qin 한국전산응용수학회 2007 Journal of applied mathematics & informatics Vol.24 No.1

The Network Attack Model based on Hierarchical Expanded Stochastic Petri Net

Yongfu Zhou 보안공학연구지원센터 2014 International Journal of Security and Its Applicat Vol.8 No.6

In the paper, a global network attack model based on Hierarchical Expanded Stochastic Petri Net (HESPN) is presented. The model is suitable for the cooperative attack simulation and can describe both macroscopic network attack and microcosmic host attack synthetically. The dissertation represents model generation algorithm and digs for potential attack relationships among hosts according to the definition of rough path. Then utilize ant colony algorithm to find k-critical vulnerable paths after expanding sub Petri net. By analyzing rough paths and accurate paths synthetically, a network risk evaluation method is proposed.

Male Grapholita molesta (Busck) adults responding to various component combinations of synthetic female sex pheromone

Guo Yongfu,Wang Yi,Chai Xiaohan,Xiang Huiming,Kong Weina,Ma Ruiyan 한국곤충학회 2022 Entomological Research Vol.52 No.9

Grapholita molesta (Busck) is a cosmopolitan fruit pest. The sex pheromones released by females have four components, namely (Z)-8-dodecenyl acetate (Z8–12:Ac), E8–12:Ac, (Z)-8-dodecen-1-ol (Z8–12:OH), and dodecanol (12:OH). This multichemical attractive system has been reported to induce various male behavioral responses, from arousal to directional flight, and enhance trapping. However, the specific male behaviors induced by individual component or component blend is unclear. This study investigated the effects of different combinations of these four components using electroantennogram, wind tunnel assays, and field tests on aspects of male behavioral performance. Our results showed that the (Z8–12:Ac + E8–12:Ac)- containing pheromones were mainly responsible for long-distance detection and close-distance location in males, including antennal detection of the stimulus, flight initiation, directional flight, and trapping. The addition of E8–12:Ac to Z8–12:Ac plays an important role in pheromone searching behavior of males in close range. The ternary component, Z8–12:Ac + E8–12: Ac + Z8–12:OH was crucial for capturing male moths, and 12:OH significantly increased the male catch. The addition of Z8–12:OH and 12:OH to Z8–12: Ac + E8–12:Ac plays an important role in completing the whole response sequence in field attraction. This study revealed that Z8–12:Ac + E8–12:Ac acts as a attractant to males, whereas Z8–12:OH, and 12:OH are the synergists that enhance male attraction in the sex pheromone blend.