Minimum Bandwidth Regenerating Codes Based on Cyclic VFR Codes

( Jing Wang ),( Shuxia Wang ),( Tiantian Wang ),( Xuefei Zhang ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.7

In order to improve the reliability and repair efficiency of distributed storage systems, minimum bandwidth regenerating (MBR) codes based on cyclic variable fractional repetition (VFR) codes are constructed in this thesis, which can repair failed nodes accurately. Specifically, in order to consider the imbalance of data accessed by the users, cyclic VFR codes are constructed according to that data with different heat degrees are copied in different repetition degrees. Moreover, we divide the storage nodes into groups, and construct MBR codes based on cyclic VFR codes to improve the file download speed. Performance analysis and simulation results show that, the repair locality of a single node failure is always 2 when MBR codes based on cyclic VFR codes are adopted in distributed storage systems, which is obviously superior to the traditional MBR codes. Compared with RS codes and simple regenerating codes, the proposed MBR codes based on cyclic VFR codes have lower repair locality, repair complexity and bandwidth overhead, as well as higher repair efficiency. Moreover, relative to FR codes, the MBR codes based on cyclic VFR codes can be applicable to more storage systems.

Surface oxidation of PAN‑based ultrahigh modulus carbon fibers (UHMCFs) and its effect on the properties of UHMCF/EP composites

Xinyu Wang,Xin Qian,Yonggang Zhang,Xuefei Wang,Shulin Song,Cheng Zhang 한국탄소학회 2021 Carbon Letters Vol.31 No.3

In this study, nitric acid oxidation with varied treatment temperature and time was conducted on the surfaces of polyacrylonitrile- based ultrahigh modulus carbon fibers. Scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and surface tension/dynamic contact angle instruments were used to investigate changes in surface topography and chemical functionality before and after surface treatment. Results showed that the nitric acid oxidation of ultrahigh modulus carbon fibers resulted in decreases in the values of the crystallite thickness Lc and graphitization degree. Meanwhile, increased treating temperature and time made the decreases more obviously. The surfaces of ultrahigh modulus carbon fibers became much more activity and functionality after surface oxidation, e.g., the total surface energy of oxidized samples at 80 °C for 1 h increased by 27.7% compared with untreated fibers. Effects of surface nitric acid oxidation on the mechanical properties of ultrahigh modulus carbon fibers and its reinforced epoxy composites were also researched. Significant decreases happened to the tensile modulus of fibers due to decreased Lc value after the nitric acid oxidation. However, surface treatment had little effect on the tensile strength even as the treating temperature and processing time increased. The highest interfacial shear strength of ultrahigh modulus carbon fibers/epoxy composites increased by 25.7% after the nitric acid oxidation. In the final, surface oxidative mechanism of ultrahigh modulus carbon fibers in the nitric acid oxidation was studied. Different trends of the tensile strength and tensile modulus of fibers in the nitric acid oxidation resulted from the typical skin–core structure.

Comparison of dry- and wet-heat induced changes in physicochemical properties of whey protein in absence or presence of inulin

Feng Gao,Xuefei Zhang,Hao Wang,Xiaomeng Sun,Jiaqi Wang,Cuina Wang 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.5

Changes in whey protein (10%, w/v) induced bydry-heating (60 C for 5 days at a relative humidity of63%), wet-heating (85 C for 30 min) or the two-combinedheating in absence or presence of inulin (8%, w/v) werestudied. Mixture of whey protein and inulin showed significantlyhigher absorbance at 290 nm than whey proteinalone in all heating conditions while only dry-heatedsamples showed significantly increased absorbance value at420 nm (p\0.05). Whey protein after heating showedsignificantly lower zeta potential and inulin decreased thevalue of all heated samples further (p\0.05) except forsamples after dry-heating. Heating decreased the freesulfhydryl group content of whey protein samples whilepresence of inulin decreased further (p\0.05). Dry-heatingdecreased while wet-heating increased the surfacehydrophobicity of whey protein. Inulin had no effect on thesurface hydrophobicity of heated whey protein under dryheatingbut decreased under wet-heating.

An integrated optimal design of energy dissipation structures under wind loads considering SSI effect

Xuefei Zhao,Han Jiang,Shuguang Wang 한국풍공학회 2019 Wind and Structures, An International Journal (WAS Vol.29 No.2

This paper provides a simple numerical method to determine the optimal parameters of tuned mass damper (TMD) and viscoelastic dampers (VEDs) in frame structure for wind vibration control considering the soil-structure interation (SSI) effect in frequency domain. Firstly, the numerical model of frame structure equipped with TMD and VEDs considering SSI effect is established in frequency domain. Then, the genetic algorithm (GA) is applied to obtain the optimal parameters of VEDs and TMD. The optimization process is demonstrated by a 20-storey frame structure supported by pile group for different soil conditions. Two wind resistant systems are considered in the analysis, the Structure-TMD system and the Structure-TMD-VEDs system. The example proves that this method can quickly determine the optimal parameters of energy dissipation devices compared with the traditional finite element method, thus is practically valuable.

One-step solvothermal synthesis of poly(arylene ether nitrile) decorated magnetic composite for methylene blue adsorption from aqueous solution

Zhou Xuefei,Miao Wei,Cheng Wenxi,Lin Haowei,Lin Haowei,Zheng Hongjuan,Cheng Qiaohuan,Wang Renjie,Yao Chenxue,Liu Xiaobo 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.6

A series of poly(arylene ether nitrile) containing versatile carboxyl and sulfonic groups (CSPEN) were magnetically functionalized by ferroferric oxide (Fe3O4), and the obtained magnetic adsorbents (Fe3O4/CSPEN) were used to remove methylene blue (MB) dye from aqueous solution. The systematical characterizations that including scanning electron microscope (SEM), X-ray powder diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), Fourier transform infrared (FTIR) certified that the Fe3O4/CSPEN possessed versatile functional groups and magnetic separation properties. The batch adsorption studies revealed that the Fe3O4/CSPEN not only displayed high selective adsorption ability for cationic MB in the presence of anionic MO, but also exhibited a removal efficiency as high as 98.2%. Besides, the adsorption kinetics and isotherm matched well with pseudo-second-order model and Langmuir model, respectively, and the maximum adsorption capacity of Fe3O4/CSPEN for MB was 92.029 mg/g. The FTIR and Brunauer-Emmett-Teller (BET) analyses confirmed that the outstanding adsorption capacity of Fe3O4/CSPEN was attributed to their own microporous structure and the electrostatic interaction with MB. Therefore, the modified magnetic adsorbent can be used to selectively remove cationic dye from aqueous solution.

Systematical characterization of functional and antioxidative properties of heat-induced polymerized whey proteins

Feng Gao,Xuefei Zhang,Jiaqi Wang,Xiaomeng Sun,Cuina Wang 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.6

Effects of pH (6–8), protein concentration (6–11%, w/v), heating temperature (70–95 C) and time (5–30 min) on functional and antioxidative properties of heat-induced polymerized whey protein were systematically investigated. All samples were determined for solubility at pH 4.6, emulsion capacity and stability, and antioxidative properties involving 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,20-azinobis(2-ethylbenzothiazoline- 6-sulfonate) (ABTS) scavenging abilities. Heating resulted in significant loss in solubility, emulsion capacity and stability for whey protein, p\0.05. Heating decreased DPPH but enhanced ABTS scavenging ability for whey protein significantly, p\0.05. Changes caused by pH variation were much stronger than those observed for other factors. Both protein concentration and heating time had negative effects while heating temperature had positive effect on emulsion capacity of whey protein. Data indicates that functional and antioxidative properties of whey protein could be altered by factors including pH, protein concentration, heating temperature and time.

Evaluation of Curtain Grouting Efficiency by Cloud Model - based Fuzzy Comprehensive Evaluation Method

Yushan Zhu,Xiaoling Wang,Shaohui Deng,Mengqi Zhao,Xuefei Ao 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.7

Because of the concealment and uncertainty of dam foundation grouting, the accurate evaluation of the quality of grouting construction is a major concern. Most of the previous studies pertaining to the assessment of grouting efficiency only take a single factor into account, and only a few efforts have been devoted to the comprehensive evaluation of grouting efficiency, which fail to consider the fuzziness problems caused by the complex relationships among indicators as well as the randomness problems caused by subjective consciousness. Therefore, the curtain grouting efficiency evaluation method considering the uncertainty in evaluation process is proposed which includes three main parts: 1) Based on conventional evaluation indicators of grouting efficiency, where groutability is introduced as a new indicator; 2) a fuzzy comprehensive evaluation method based on cloud model is developed, by which the fuzziness and randomness in assessment are organically combined; and 3) the fuzzy entropy was calculated for indicating the complexity of grouting efficiency level. Then, the proposed method is used to assess efficiency of the curtain grouting for a hydropower station in China, and compared with three other methods. The outcomes display the consistency, representativeness, robustness and superiority of this evaluation method, which make the evaluation results more scientific and objective.

A Light-Inducible Bidirectional Promoter Initiates Expression of Both Genes SHH2 and CFM3 in Brassica napus L.

Ruijia Zhu,Li Zhang,Tao Wei,Xuefei Jiang,Maolin Wang 한국식물학회 2023 Journal of Plant Biology Vol.66 No.5

A bidirectional promoter is an intergenic region between a pair of adjacent and oppositely transcribed genes (‘head-to-head’ genes) that concurrently initiates the expression of both genes. In this work, we identified a bidirectional promoter PBn265 with a 265 bp sequence between transcription initiation codons (ATG) of two genes encoding the homeodomain protein SHH2 and chloroplast GROUP II intron splicing factor CFM3, respectively, in genome of Brassica napus. The histochemical staining and fluorescence microscopy results demonstrated that PBn265 possess bidirectional promoting activity in the various tissues of the transgenic Arabidopsis thaliana. Notably, the bidirectional expression activities of PBn265 were significantly increased following red or blue light induction. Furthermore, the gene structure, ‘SHH2-BiP-CFM3’, appears highly conservative among various species in Brassicaceae. Considering its short sequence length, high sequence conservation and light-inducible properties, this promoter from Brassica napus most likely has application potential in bioengineering and agricultural molecular breeding.

Porous Nano-Ni/Graphene/Loofah Composites for Electromagnetic Interference Shielding

Yi Jiang,Mingwei Liang,Weijing Wang,Xuefei Lai,Kenan Xie,Li Liao,Qin Long 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.4

The urgent requirement of materials with superior electromagnetic shielding properties has been aroused for alleviating electromagnetic pollution. Now, some natural materials such as silkworm cocoon, walnut shell, and so on are gradually used to prepare the electromagnetic interference shielding composites. However, loofah sponges with unique and inherent 3D hierarchical porous structure, which could be obtained from food waste and the wilted loofah, are ignored. In this work, loofah sponges were modified by NaOH and H2 O2 . Then the carbonized modified Loofah/Ni nanoparticles/Graphene composites were prepared by immersion and thermal reduction. Meanwhile, the composites had inherited advantages from natural materials such as low density, porous structure and eco-friendly. As the result of loading of Ni nanoparticles and graphene on the loofah, the outstanding performance was achieved that the shielding effectiveness was raised to 57 dB, and the specific shielding effectiveness was raised to 616.8 dB cm 3 /g. This result demonstrated that composites materials based on natural loofah sponges show tremendous potential for electromagnetic shielding.

Seismic Analysis and Evaluation of Y-shaped EBF with an Innovative SSL-SSBC

Shujun Hu,Sizhi Zeng,Jingang Xiong,Xuefei Wang,Qiang Zhou,Xiong Xinfu 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.3

During severe earthquakes, the ductility and energy dissipation capacity of shear links in Y-shaped eccentrically braced frames (EBFs) are crucial to achieve desirable seismic performance and structural safety. In this study, an innovative SSLSSBC combining the advantages of a shear slotted bolted connection (SSBC) and a very short shear link is developed to improve the seismic performance of Y-shaped EBFs. Finite element (FE) analysis methods are fi rst validated through comparison with existing experimental results for slotted bolted connection and very short shear links. Further, FE simulations of the SSBC, very short shear link with shear slotted bolted connection (SSL-SSBC), and Y-shaped EBF are conducted to determine their mechanical behavior systematically. The FE results demonstrate that a reasonable SSBC can eff ectively increase the ductility and energy dissipation capacity through friction slipping, allowing the SSBC to maintain elastic behavior throughout the entire range of seismic loading, while the very short shear link in the SSL-SSBC could undergo severe damage to dissipate seismic energy. As expected, the SSL-SSBC is capable of working as both a shear dissipation damper and a metallic ductile damper in the Y-shaped EBF. This study also clearly identifi es that no yielding or damage of the very short shear links occurs during small and medium earthquakes, and the deformation and damage of the very short shear link can be minimized during severe earthquakes, allowing the seismic resilience capacity of the Y-shaped EBF to be dramatically enhanced.