Effects of Different Raising Ways on the Early Growth and Development Performance of Nanjiang Yellow Goat

Luo Hailing,Xu Yongfeng,Zhang Yingjun,Zhang Xiaohong,Liu Kai 한국초지조사료학회 2009 한국초지조사료학회 학술대회논문집 Vol.2009 No.08

A total of 106 two month-old Nanjiang yellow goats (male were 32, female were 34 and castrated were 40) were divided into treatment group and control group to determine the growth performance. The treatment group was reared in grazing mode, experimental group was pastured with supplement feeding. The results showed that the body weight of male in experiment group was heavier by 9.82%(P<0.05), 11.87%(P<0.01), 16.91%(P<0.01) and 23.99%(P<0.05) than that in control group in 3,4,5 and 6 month-age. The body weight of female in experimental group was heavier by 11.54%(P<0.05), 13.79%(P<0.01), 17.47%(P<0.01) and 21.15%(P<0.01) than that in control group in 3,4,5 and 6 month-old. The body weight of castrator in experimental group was heavier by 1.58%, 1.99%, 13.08%(P<0.01) and 15.76%(P<0.01) than that in control group in 3,4,5 and 6 month-age. The daily increasing weight and body measurements of experimental group is improved more than control group, especially in 6 month-age.

Geometric Imperfection Distributions of Existing Reticulated Shells: Theoretical and Experimental Analysis

Wu Jun,Luo Yongfeng,Wang Lei 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.5

Geometric imperfection is one of the most disadvantageous factors that impair mechanical behaviors of existing reticulated shell structures. However, the available consistent mode methods and statistical methods which usually applied in designing structures can hardly estimate the actual geometric imperfection distribution for existing structures, because these methods use the assumed imperfections. In this paper, a Markov Random Field (MRF) theoretical model of existing reticulated shells is established by introducing the theory of probabilistic graphical model. The unit of graphic model named node clique are proposed to deduct the geometric state function of reticulated shells, based on the local Markov property. Then the inversion function along with its iterative equation is established to predict geometric imperfection distribution of existing reticulated shells. The MRF method makes the predicted distribution of the numerical model as consistent as possible with its corresponding actual structure, and only a few measurement nodes are needed as known conditions. An experimental structure of K6 single-layer reticulated shell is built to verify the proposed theory by comparing the calculated geometric imperfection distribution results with the actual measured data. Meanwhile, the signifi cance level of the calculated results between MRF and traditional stochastic method is analyzed, which shows MRF method can eff ectively predict the geometric imperfections of single layer reticulated shells.

Text Steganography Based on Ci-poetry Generation Using Markov Chain Model

나유박 ( Yubo Luo ),황영봉 ( Yongfeng Huang ),이복방 ( Fufang Li ),장진성 ( Chinchen Chang ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.9

Steganography based on text generation has become a hot research topic in recent years. However, current text-generation methods which generate texts of normal style have either semantic or syntactic flaws. Note that texts of special genre, such as poem, have much simpler language model, less grammar rules, and lower demand for naturalness. Motivated by this observation, in this paper, we propose a text steganography that utilizes Markov chain model to generate Ci-poetry, a classic Chinese poem style. Since all Ci poems have fixed tone patterns, the generation process is to select proper words based on a chosen tone pattern. Markov chain model can obtain a state transfer matrix which simulates the language model of Ci-poetry by learning from a given corpus. To begin with an initial word, we can hide secret message when we use the state transfer matrix to choose a next word, and iterating until the end of the whole Ci poem. Extensive experiments are conducted and both machine and human evaluation results show that our method can generate Ci-poetry with higher naturalness than former researches and achieve competitive embedding rate.

Practical Residual Force Decomposition Method for Damage Identifi cation of Existing Reticulated Shells

Jun Wu,Yongfeng Luo,Lei Wang 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.6

The non-destructive damage identifi cation approaches for existing structures become more of a concern due to safety requirements. However, the application of damage identifi cation method is still limited for complex spatial structures. In this paper, a practical residual force decomposition (RFD) method is proposed to identify damaged members in existing reticulated shell structures. A parameterized model is built by taking the stiff ness reduction into consideration. In the proposed RFD method, the signifi cant damage can be recognized corresponding to the changes of the observed eigenvector of the reticulated shells, and the eigenvector changes can be easily transferred to a set of multivariate linear equations to locate the members with signifi cant stiff ness reduction. The inputs of the equations are discussed including the additional constraints and the selection of eff ective modes. According to the diff erent proportion of the numbers of members and joints, three situations of the solution are discussed. Especially when the solution is not unique, the importance coeffi cients of structural members are introduced as additional constraints through Ritz vector sensitivity analysis and application of the Modal Assurance Criterion. Two illustrative examples including a single-layer Kiewitt-6 reticulated shell and a structural model of international convention center are adopted to demonstrate the eff ectiveness of the approach. The results show that the proposed method can yield a suitable damage identifi cation.

Block Tearing and Local Buckling of Aluminum Alloy Gusset Joint Plates

Xiaonong Guo,Zhe Xiong,Yongfeng Luo,Han Xu,Shuiping Liang 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.2

Aluminum Alloy Gusset (AAG) joints widely used in the single-layer latticed shells have a significant application prospect in spatial structures. Unfortunately, studies on the resistance of AAG joints are insufficient, leading to a lack of applicative design methods for this joint system. This paper is devoted to investigate the resistance of AAG joint plates. Firstly, tests on fourteen AAG joint specimens are carried out to explore their collapse modes. Experimental phenomena show that the main collapse modes of AAG joint plates include the block tearing of top plates and the local buckling of bottom plates. Secondly, Finite Element (FE) simulations to investigate the mechanical behavior of AAG joints are performed by means of the non-linear FE code ABAQUS. Thirdly, formulae for predicting the block tearing resistance and the local buckling resistance of AAG joint plates are proposed, which are based on theoretical analyses. Fourthly, test results are of great help in the determination of parameters k and α which are adopted to modify the block tearing resistance and the local buckling resistance respectively. Finally, a comparison of test results verifies that theoretical formulae are applicable. In addition, in order to avoid the block tearing and the local buckling of AAG joint plates, convenient design criteria are provided.

Experimental and Theoretical Study on High Strength Steel Extended Endplate Connections After Fire

Xuhong Qiang,Nianduo Wu,Yongfeng Luo,Xu Jiang,Frans Bijlaard 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.2

In order to reveal more information and better understanding on the behavior and failure mechanisms of high strength steel (HSS) extended endplate connections at ambient temperature and after fi re, an experimental and theoretical study has been conducted and presented in this paper. The provisions of Eurocode 3 are verifi ed with the test results. Because strength of bolts decreases more rapidly than that of structural steels, failure modes of endplate connections may change after fi re. Hence, a series of equations are proposed to predict failure modes of endplate connections after fi re. Furthermore, FE simulations which can predicate the performance of HSS extended endplate connections with reasonable accuracy are adopted to study the behaviors of the connections after cooling down from various fi re temperatures and to validate the accuracy of the proposed equations. Moreover, a parametric study is carried out to explore an optimization design method. It is found that the current provisions of EC3 can justifi ably predict failure modes and plastic fl exural resistances of HSS extended endplate connections both at ambient temperature and cooling down from 550 °C, but it is not the case for their initial rotational stiff - ness and rotation capacity. In order to avoid brittle failure mode of endplate connections after fi re, appropriately increasing the diameter or grade of bolts in the design is suggested. What is more, the match of steel grade and thickness of column fl ange and endplate as well as beam should be considered in the optimization design of beam-column endplate connections.

Seismic Performance of New-type Box Steel Bridge Piers with Embedded Energy-Dissipating Shell Plates under Tri-directional Seismic Coupling Action

Haifeng Li,Xuanneng Gao,Yang Liu,Yongfeng Luo 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.1

Accurate numerical models are necessary to evaluate the seismic performance and load-bearing mechanism of new-type box steel bridge piers with embedded energy-dissipating shell plates under tri-directional seismic coupling action. Numerical simulations of seismic performance under six types of tri-directional seismic coupling action was conducted. The effects of this stress on the seismic performance of the new-type steel bridge piers was evaluated through analysis of damage mode, hysteresis curve, skeleton curve, stiffness and strength degradation characteristic, and energy-dissipating capacity. This study also compared the numerical analysis with experimental results in order to validate the accuracy of the proposed finite element model. Based on this model, the range of relevant parameters expanded and 88 numerical specimens were analysed for seismic performance, producing further information about the influence of thickness and curvature of the embedded shell plate, spacing of transverse stiffening ribs of the shell, axial compression ratio, and slenderness ratio. Results showed that tri-directional seismic coupling action significantly affects the specimen’s deformation capacity; the embedded shell plate effectively improves the piers’ loadcarrying and deformation capacity; and the thickness of the embedded shell plate, width-to-thickness ratio of the wall plate, axial compression ratio, and slenderness ratio significantly affect the seismic performance of the new-type steel bridge piers. To promote the ease of seismic design of new-type box steel bridge piers, this study used theoretical analysis and numerical simulation to calculate equations for the minimum height of the energy-dissipating zone of the bottom embedded shell plate. Finally, formulas were also established to calculate the relevant stability bearing capacity and displacement ductility factor of the new-type steel bridge piers under tri-directional seismic coupling action in order to improve their seismic design.

Experimental and Numerical Analysis on Full High Strength Steel Extended Endplate Connections in Fire

Xuhong Qiang,Nianduo Wu,Xu Jiang,Yongfeng Luo,Frans Bijlaard 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.4

Full-scale experimental study and numerical analysis on behaviors and failure mechanisms of full high strength steel extended endplate connections in fi re have been carried out and presented in this paper. The experimental behaviors of the connections were compared with the provisions of Eurocode 3. The test results show that the failure modes of the connections in fi re are bolt failure with yielding of the fl ange, as same as those at ambient temperature. The failures of the bolts in fi re are ductile while they are brittle at ambient temperature. The rotation capacity of the connections in fi re is proved suffi cient. What is more, at elevated temperature 550 °C, the plastic moment resistances of Q690 and Q960 full high strength steel endplate connections are only 40% of those at ambient temperature, while their initial rotation stiff ness are 66 and 63% respectively. But the rotation capacities of Q690 and Q960 high strength steel endplate connections are 1.38 and 1.74 times of those at ambient temperature. Moreover, it is found that the component method Eurocode 3 proposed based on connections made of mild steels can be used to calculate plastic resistances and to predict failure modes of high strength steel endplate connections in fi re, but it is not suitable to predict their stiff ness. The suggestions about rotation capacity of connections in Eurocode 3 are found too conservative for high strength steel endplate connections in fi re.

UEPF:A blockchain based Uniform Encoding and Parsing Framework in multi-cloud environments

( Dehao Tao ),( Zhen Yang ),( Xuanmei Qin ),( Qi Li ),( Yongfeng Huang ),( Yubo Luo ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.8

The emerging of cloud data sharing can create great values, especially in multi-cloud environments. However, “data island” between different cloud service providers (CSPs) has drawn trust problem in data sharing, causing contradictions with the increasing sharing need of cloud data users. And how to ensure the data value for both data owner and data user before sharing, is another challenge limiting massive data sharing in the multi-cloud environments. To solve the problems above, we propose a Uniform Encoding and Parsing Framework (UEPF) with blockchain to support trustworthy and valuable data sharing. We design namespace-based unique identifier pair to support data description corresponding with data in multi-cloud, and build a blockchain-based data encoding protocol to manage the metadata with identifier pair in the blockchain ledger. To share data in multi-cloud, we build a data parsing protocol with smart contract to query and get the sharing cloud data efficiently. We also build identifier updating protocol to satisfy the dynamicity of data, and data check protocol to ensure the validity of data. Theoretical analysis and experiment results show that UEPF is pretty efficient.