The Heuristic Algorithm of Wavelet Image Denoising Based on Rough Set

Song Lan,Lei Lixia,Li Haisheng,Hong Wang 보안공학연구지원센터(IJSIP) 2014 International Journal of Signal Processing, Image Vol.7 No.6

In this paper, we propose a novel approach to explore image denoising for patch based image process. The importance measurement model of Rough Entropy and the importance reduction method of wavelet coefficients are given. This paper combines the rough set theory with the denoising method of wavelet threshold, regarding the high-frequency information blocks in the transform domain as similar ones, and adopting importance Reduction Methods to contract the coefficients. The simulation results show that this method is effective.

Mechanism analysis on fluidelastic instability of tube bundles in considering of cross-flow effects

Jiang Lai,Lei Sun,Lixia Gao,Pengzhou Li 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.1

Fluidelastic instability is a key issue in steam generator tube bundles subjected in cross-flow. With a lowflow velocity, a large amplitude vibration of the tube observed by many researchers. However, themechanism of this vibration is seldom analyzed. In this paper, the mechanism of cross-flow effects onfluidelastic instability of tube bundles was investigated. Analysis reveals that when the system reachesthe critical state, there would be two forms, with two critical velocities, and thus two expressions for thecritical velocities were obtained. Fluidelastic instability experiment and numerical analysis were conductedto obtain the critical velocity. And, if system damping is small, with increases of the flow velocity,the stability behavior of tube array changes. At a certain flow velocity, the stability of tube array reachesthe first critical state, a dynamic bifurcation occurs. The tube array returns to a stable state with continuesto increase the flow velocity. At another certain flow velocity, the stability of tube array reachesthe second critical state, another dynamic bifurcation occurs. However, if system damping is big, there isonly one critical state with increases the flow velocity. Compared the results of experiments to numericalanalysis, it shows a good agreement.

Fluidelastic instability of a tube array in two-phase cross-flow considering the effect of tube material

Huantong Liu,Jiang Lai,Lei Sun,Pengzhou Li,Lixia Gao,Danping Yu 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.8

Fluidelastic instability of a tube array is a key factor of the security of a nuclear power plant. An unsteady model of the fluidelastic instability of a tube array subjected to two-phase flow was developed to analyze the fluidelastic instability of tube bundles in two-phase flow. Based on this model, a computational program was written to calculate the eigenvalue and the critical velocity of the fluidelastic instability. The unsteady model and the program were verified by comparing with the experimental results reported previously. The influences of void fraction and the tube's material properties on the critical velocity were investigated. Numerical results showed that, with increasing the void fraction of the two-phase flow, the tube array becomes more stable. The results indicate that the critical velocities of the tube array made of stainless are much higher than those of the other two tube arrays within void fraction ranging from 20%to 80%.

Investigating Impacts of CoronaVac Vaccination in Males on In Vitro Fertilization: A Propensity Score Matched Cohort Study

Wang Meng,Yang Qiyu,Zhu Lixia,Jin Lei 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.4

Purpose: This study aimed to evaluate the influences of SARS-CoV-2 vaccination (CoronaVac) on male fertility and investigate the impact of a history of the CoronaVac vaccination in males on gamete and embryo development and in vitro fertilization (IVF) outcomes. Materials and Methods: A prospective cohort study enrolled couples undergoing IVF cycles between June and August 2021 at Reproductive Medicine Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology in China. According to the history of SARS-CoV-2 vaccination in males, the participants were divided into the vaccination group and the non-vaccination group. A self-controlled study of semen analyses for males before and after CoronaVac vaccination was conducted. Baseline characteristics were matched using propensity score matching. Participants were categorized into the unexposed group (non-vaccination) and exposed group (vaccination), and the population was 271 for each. Semen parameters and IVF outcomes were the main outcomes. Results: Generally, no statistically significant differences were exhibited between the matched cohorts regarding embryo developmental parameters, including fertilization rate, cleavage rate, high-quality embryo rate, blastocyst formation rate, and available blastocyst rate, as well as clinical outcomes, such as implantation rate, biochemical pregnancy rate, and clinical pregnancy rate. Moreover, males after vaccination seemed to have fluctuating semen parameters including increased semen volume, lower motility, and decreased normal forms of sperm, while the motile sperm counts were similar. In addition, all semen parameters were above the lower reference limits. Conclusions: Our findings suggested that CoronaVac vaccinations in males may not have adverse effects on patient performance or the gamete and embryonic development potential during assisted reproductive technology (ART) treatments.

Locating QTLs controlling overwintering seedling rate in perennial glutinous rice 89-1 (Oryza sativa L.)

Xiaoshu Deng,Lu Gan,Yan Liu,Ancai Luo,Liang Jin,Jiao Chen,Ruyu Tang,Lixia Lei,Jianghong Tang,Jiani Zhang,Zhengwu Zhao 한국유전학회 2018 Genes & Genomics Vol.40 No.12

A new cold tolerant germplasm resource named glutinous rice 89-1 (Gr89-1, Oryza sativa L.) can overwinter using axillary buds, with these buds being ratooned the following year. The overwintering seedling rate (OSR) is an important factor for evaluating cold tolerance. Many quantitative trait loci (QTLs) controlling cold tolerance at different growth stages in rice have been identified, with some of these QTLs being successfully cloned. However, no QTLs conferring to the OSR trait have been located in the perennial O. sativa L. To identify QTLs associated with OSR and to evaluate cold tolerance. 286 F12 recombinant inbred lines (RILs) derived from a cross between the cold tolerant variety Gr89-1 and cold sensitive variety Shuhui527 (SH527) were used. A total of 198 polymorphic simple sequence repeat (SSR) markers that were distributed uniformly on 12 chromosomes were used to construct the linkage map. The gene ontology (GO) annotation of the major QTL was performed through the rice genome annotation project system. Three main-effect QTLs (qOSR2, qOSR3, and qOSR8) were detected and mapped on chromosomes 2, 3, and 8, respectively. These QTLs were located in the interval of RM14208 (35,160,202 base pairs (bp))–RM208 (35,520,147 bp), RM218 (8,375,236 bp)–RM232 (9,755,778 bp), and RM5891 (24,626,930 bp)–RM23608 (25,355,519 bp), and explained 19.6%, 9.3%, and 11.8% of the phenotypic variations, respectively. The qOSR2 QTL displayed the largest effect, with a logarithm of odds score (LOD) of 5.5. A total of 47 candidate genes on the qOSR2 locus were associated with 219 GO terms. Among these candidate genes, 11 were related to cell membrane, 7 were associated with cold stress, and 3 were involved in response to stress and biotic stimulus. OsPIP1;3 was the only one candidate gene related to stress, biotic stimulus, cold stress, and encoding a cell membrane protein. After QTL mapping, a total of three main-effect QTLs—qOSR2, qOSR3, and qOSR8—were detected on chromosomes 2, 3, and 8, respectively. Among these, qOSR2 explained the highest phenotypic variance. All the QTLs elite traits come from the cold resistance parent Gr89-1. OsPIP1;3 might be a candidate gene of qOSR2.