Study on fracture characteristics of reinforced concrete wedge splitting tests

Hu Shaowei,XU Aiqing,HU Xin,YIN Yangyang 사단법인 한국계산역학회 2016 Computers and Concrete, An International Journal Vol.18 No.3

To study the influence on fracture properties of reinforced concrete wedge splitting test specimens by the addition of reinforcement, and the restriction of steel bars on crack propagation, 7 groups reinforced concrete specimens of different reinforcement position and 1 group plain concrete specimens with the same size factors were designed and constructed for the tests. Based on the double-K fracture criterion and tests, fracture toughness calculation model which was suitable for reinforced concrete wedge splitting tensile specimens has been obtained. The results show that: the value of initial craking load Pini and unstable fracture load Pun decreases gradually with the distance of reinforcement away from specimens’s top. Compared with plain concrete specimens, addition of steel bar can reduce the value of initial fracture toughness KIini, but significantly increase the value of the critical effective crack length ac and unstable fracture toughness KIun. For tensional concrete member, the effect of anti-cracking by reinforcement was mainly acted after cracking, the best function of preventing fracture initiation was when the steel bar was placed in the middle of the crack, and when the reinforcement was across the crack and located away from crack tip, it plays the best role in inhibiting the extension of crack.

Candidate Pruning-Based Differentially Private Frequent Itemsets Mining

Yangyang Xu,Zhaobin Liu,Zhonglian Hu,Zhiyang Li 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.7

Frequent Itemsets Mining(FIM) is a typical data mining task and has gained much attention. Due to the consideration of individual privacy, various studies have been focusing on privacy-preserving FIM problems. Differential privacy has emerged as a promising scheme for protecting individual privacy in data mining against adversaries with arbitrary background knowledge. In this paper, we present an approach to exploring frequent itemsets under rigorous differential privacy model, a recently introduced definition which provides rigorous privacy guarantees in the presence of arbitrary external information. The main idea of differentially privacy FIM is perturbing the support of item which can hide changes caused by absence of any single item. The key observation is that pruning the number of unpromising candidate items can effectively reduce noise added in differential privacy mechanism, which can bring about a better tradeoff between utility and privacy of the result. In order to effectively remove the unpromising items from each candidate set, we use a progressive sampling method to get a super set of frequent items, which is usually much smaller than the original item database. Then the sampled set will be used to shrink candidate set. Extensive experiments on real data sets illustrate that our algorithm can greatly reduce the noise scale injected and output frequent itemsets with high accuracy while satisfying differential privacy.

Differential Privacy via Weighted Sampling Set Cover

Zhonglian Hu,Zhaobin Liu,Yangyang Xu,Zhiyang Li 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.4

Differential privacy is a security guarantee model which widely used in privacy preserving data publishing, but the query result can’t be used in data research directly, especially in high-dimensional datasets. To address this problem, we propose a dimensionality reduction method. The core idea of this method is using a series of low-dimensional datasets to reconstruct a high-dimensional dataset, it improves data availability eventually. The main issue of this method is the reconstruction integrity, so a special sampling via set cover model is proposed in this article, which builds a multidimensional composite marginal tables set as a new middleware in differential privacy model. As a result, any form of disjunctive queries can be answered, and the accuracy of data query is improved. The experiment results also show the effectiveness of our method in practice.

Comparative experimental study of ethanol-air premixed laminar combustion characteristics by laser induced spark and electric spark ignition

Cangsu Xu,Yangyang Hu,Xiaolu Li,Xuan Zhou,Anhao Zhong 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.2

An experimental study of laminar combustion characteristics of ethanol-air premixed mixtures was conducted with different ignition methods, including laser induced spark ignition (LISI) and electric spark ignition (SI) at an initial condition of 358 K temperature and 0.1MPa pressure. Flame propagation with the two different ignition methods was analyzed and discussed. The laminar flame speed was extrapolated with a nonlinear extrapolation method. Results indicate that the laminar speed of ethanol-air mixtures with LISI is faster than that with SI at lean mixtures, but slower at stoichiometric and rich mixtures. The peak values of the laminar burning velocity for SI and LISI with nonlinear extrapolation are 50.1 cm/s and 47.6 cm/s at the equivalence ratio of 1.1, respectively. Laser-induced spark ignition is able to ignite leaner ethanol-air mixtures.

Plasma-catalytic decomposition of ethyl acetate over LaMO3 (M = Mn, Fe, and Co) perovskite catalysts

Yuxiang Cai,Xinbo Zhu,Wenshuo Hu,Chenghang Zheng,Yangyang Hu,Menghan Chen,Xiang Gao 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.70 No.-

Plasma-catalytic decomposition of low concentration ethyl acetate with LaMO3 (M = Co, Mn and Fe)perovskite catalyst was investigated in a coaxial dielectric barrier discharge (DBD) reactor. Thecombination of perovskite catalyst and plasma enhanced ethyl acetate decomposition, and the activitysequence was LaCoO3> LaMnO3> LaFeO3. Characterizations results indicated that the activation ofsurface oxygen species and amount of oxygen vacancies contributed to ethyl acetate decompositionremarkably. FT-IR analysis demonstrated that the employment of LaCoO3 catalyst also reduced theamount of unwanted by-products. Based on these results, reaction mechanism of ethyl acetate plasmacatalyticdecomposition process was proposed.

Evaluation of surface texture of dried Hami Jujube using optimized support vector machine based on visual features fusion

Xiuzhi Luo,Benxue Ma,Wenxia Wang,Shengyuan Lei,Yangyang Hu,Guowei Yu,Xiaozhan Li 한국식품과학회 2020 Food Science and Biotechnology Vol.29 No.4

The surface texture of dried jujube fruits is a significant quality grading criterion. This paper introduced a novel visual feature fusion based on connected region density, texture features, and color features. The singlescale Two-Dimensional Discrete Wavelet Transform was used to perform single-scale decomposition and reconstruction of dried Hami jujube image before visual features extraction. The connected region density was extracted by the two different algorithms, whereas the texture features were extracted by Gray Level Co-occurrence Matrix and the color features were extracted by image processing algorithms. Based on selected features which obtained by correlation analysis of visual features, the accuracy rate of the optimized Support Vector Machine classification model was 96.67%. In comparing with Extreme Learning Machine classification model and other fusion methods, the optimized Support Vector Machine based on selected visual features fusion was better.

Association between expression levels and growth trait-related SNPs located in promoters of the MC4R and MSTN genes in Spinibarbus hollandi

Yang Yang,Zhaojun Lan,Hu Shu,Huiqiang Zhou,Xiaolu Jiang,Liping Hou,Pinghua Gu 한국유전학회 2018 Genes & Genomics Vol.40 No.11

Melanocortin 4 receptor: (MC4R) and Myostatin (MSTN) are two important growth trait-related genes in animals. In this study, we showed that two SNPs, MC4R-719A>G and MSTN-519C>T, found in the promoters of the MC4R and MSTN genes, respectively, are both associated with growth traits in Spinibarbus hollandi. Furthermore, we observed that there were significant associations between the expression levels of the MC4R and MSTN genes and these two growth trait-related SNPs. The expression level of MC4R gene in brain was lower in GG genotype fish with extremely high growth performance than that in AA genotype fish with extremely low growth performance. Expression level of the MSTN gene in muscle was lower in TT genotype fish with extremely high growth performance than that in CC and CT genotype fish with lower growth performance. The results indicated that these SNPs located in the promoters of MC4R and MSTN are associated with growthrelated traits through modification of gene expression levels. The MSTN and MC4R SNPs may have useful application in effective marker-assisted selection aimed to increase output in S. hollandi.

An Efficient Biometric Identity Based Signature Scheme

( Yang Yang ),( Yupu Hu ),( Leyou Zhang ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.8

The combination of biometrics and cryptography gains a lot of attention from both academic and industry community. The noisy biometric measurement makes traditional identity based cryptosystems unusable. Also the extraction of key from biometric information is difficult. In this paper, we propose an efficient biometric identity based signature scheme (Bio-IBS) that makes use of fuzzy extractor to generate the key from a biometric data of user. The component fuzzy extraction is based on error correction code. We also prove that the security of suggested scheme is reduced to computational Diffie-Hellman (CDH) assumption instead of other strong assumptions. Meanwhile, the comparison with existing schemes shows that efficiency of the system is enhanced.

Pt-functionalized S-doped g-C3N4 nanosheet for sensitive electrochemical determination of sulfamonomethoxine

Yang Yang,Hu Huali,Ai Jixing,Wang Hong,Du Haijun 한국탄소학회 2024 Carbon Letters Vol.34 No.3

Sulfamonomethoxine (SMM) is widely used to inhibit Gram-positive and Gram-negative bacteria, and improper use of SMM is detrimental to human health and ecological stability. Therefore, a sensitive determination method is of great importance for monitoring SMM residues in water, meat, milk, eggs, etc. Herein, a Pt-functionalized S-doped graphitic carbon nitride (Pt/S-g-C3N4) was constructed for the electrochemical determination of SMM. The as-developed Pt3/S3-g-C3N4 sensor showed a significant SMM determination performance. The electrochemical oxidation of SMM on Pt3/S3-g-C3N4/GCE involves two electron transference and was limited by a diffusion process. The as-developed Pt3/S3-g-C3N4/GCE sensor has good linearity in a wide range of 0.1–120 μmol/L and a remarkably low limit of detection (LOD) of 0.026 μmol/L for SMM determination. In addition, the sensor has high selectivity and anti-interference properties for SMM detection. Furthermore, this Pt3/S3-g-C3N4/GCE sensor has good reproducibility and stability. Moreover, the recoveries were in the range of 89.6–112.2% for the detection of the SMM in a real sample of egg. The proposed Pt3/S3-g-C3N4/GCE sensor shows great potential for practical applications in detecting trace amounts of antibiotics.

Dynamic Caching Routing Strategy for LEO Satellite Nodes Based on Gradient Boosting Regression Tree

( Yang Yang ),( Shengbo Hu ),( Guiju Lu ) 한국정보처리학회 2024 Journal of information processing systems Vol.20 No.1

A routing strategy based on traffic prediction and dynamic cache allocation for satellite nodes is proposed to address the issues of high propagation delay and overall delay of inter-satellite and satellite-to-ground links in low Earth orbit (LEO) satellite systems. The spatial and temporal correlations of satellite network traffic were analyzed, and the relevant traffic through the target satellite was extracted as raw input for traffic prediction. An improved gradient boosting regression tree algorithm was used for traffic prediction. Based on the traffic prediction results, a dynamic cache allocation routing strategy is proposed. The satellite nodes periodically monitor the traffic load on inter-satellite links (ISLs) and dynamically allocate cache resources for each ISL with neighboring nodes. Simulation results demonstrate that the proposed routing strategy effectively reduces packet loss rate and average end-to-end delay and improves the distribution of services across the entire network.