异构超混沌系统有限时间组合-组合同步及应用

为有效提高保密通信系统的安全性,在混沌组合同步的基础上提出一种基于有限时间理论的异结构超混沌系统组合-组合同步方案,并将其应用于混沌掩盖保密通信。选取四种具有普适性的经典超混沌系统作为研究对象;结合有限时间理论和Lyapunov稳定理论,利用反步法设计异结构超混沌系统的组合-组合同步控制方案,在数学理论上证明了方案的合理性,并通过数值仿真和对比实验验证了有限时间控制方案的高效性和对外部干扰的强鲁棒性;利用该有限时间组合—组合同步设计了混沌掩盖保密通信方案,仿真结果表明在外部干扰和信道噪声存在的条件下此方案能快速有效地恢复出原始信息信号,具有较强的抗破译性。

多个混沌系统的有限时多切换“组合-组合”同步

针对多个实变量混沌系统,研究一类基于多切换传输模式的有限时"组合-组合"同步问题.首先,分析了多个混沌系统之间的切换同步行为,并给出了有限时"组合-组合"同步的定义.其次,依据有限时稳定性理论,设计了一类新的实现快速同步的控制方案,并给出了实现有限时"组合-组合"同步误差系统渐近稳定的充分条件.最后,通过数值仿真和分析验证了所设计有限时同步控制方案的有效性.

上承式钢管-砼桁架组合梁桥计算分析及应用

由钢板单元为基本元组成的钢箱形结构以其受力合理,承载力大等优势,在钢结构桥梁中应用较多。但是由于面外稳定性问题,钢板需配合纵横向加劲板方能使用,由此带来焊接工作量较大等一系列问题。文章提出基于钢管结构的上承式钢管-混凝土桁架组合梁的桥型方案,并选取一个工程项目进行对比计算分析,验证了该桥型方案的可行性。同时,针对计算过程中发现的问题,文章查阅了相关文献及类似研究内容,提出了相应的解决方案。该种桥型结构新颖、造型美观、理论体系成熟,是一种值得推广采用的桥梁结构形式。

CHC-TSCM:A Trustworthy Service Composition Method Based on an Improved CHC Genetic Algorithm

Trustworthy service composition is an extremely important task when service composition becomes infeasible or even fails in an environment which is open,autonomic,uncertain and deceptive.This paper presents a trustworthy service composition method based on an improved Cross generation elitist selection,Heterogeneous recombination,Catacly-smic mutation(CHC) Trustworthy Service Composition Method(CHC-TSCM) genetic algorithm.CHCTSCM firstly obtains the total trust degree of the individual service using a trust degree measurement and evaluation model proposed in previous research.Trust combination and computation then are performed according to the structural relation of the composite service.Finally,the optimal trustworthy service composition is acquired by the improved CHC genetic algorithm.Experimental results show that CHC-TSCM can effectively solve the trustworthy service composition problem.Comparing with GODSS and TOCSS,this new method has several advantages:1) a higher service composition successrate;2) a smaller decline trend of the service composition success-rate,and 3) enhanced stability.

Effects of minor Sr, Sn and Sc addition on as-cast microstructure and mechanical properties of ZA84 magnesium alloy

The effects of minor Sr, Sn and Sc addition on the as-cast microstructure and mechanical properties of the ZA84 magnesium alloy were compared. The results indicate that addition of 0.1%Sr, 0.5%Sn or 0.3%Sc (mass fraction) to the ZA84 alloy can refine the grains of the alloy. Furthermore, addition of 0.1%Sr to the ZA84 alloy does not obviously change the morphology and distribution of Mg32(Al,Zn)49 phase. However, addition of 0.5%Sn or 0.3%Sc not only refines and modifies the Mg32(Al,Zn)49 phase but also suppresses the formation of Mg32(Al,Zn)49 phase, especially with the addition of 0.3%Sc. Furthermore, addition of 0.1%Sr, 0.5%Sn or 0.3%Sc to the ZA84 alloy improves the tensile properties at room temperature and 150℃, especially with the addition of 0.1%Sr and 0.3%Sc. However, addition of 0.1%Sr is not beneficial to the creep properties, and addition of 0.5%Sn has no obvious influence on the creep properties. Oppositely, addition of 0.3%Sc to the ZA84 alloy greatly improves the creep properties.

Combinatorial Optimization of Ba/Fe-cordierite Solid Solution （Ba0.05Fe0.1Mg）2Al4Si5O18 for High Infrared Radiance Materials

A combinatorial chemistry method was employed to screen the Ba2＋ and Fe3＋ incorporated into cordierite structure （Ba0.05Fe0.1Mg）2A14Si5018 for exploring of high infrared radiance materials. A series of square-type sample array that consists of 7×7 compositions was syn- thesized by ink-jetting nitrate solutions into micro-reactor wells in a ceramic plate and then heat-treated at high temperatures. X-ray diffraction and infrared thermograph were used to analyze the effects of Ba2＋/Fe3＋ incorporating on the lattice distortion of cordierite and resultant changes in infrared radiance properties. Based on the results of X-ray phase analy- sis and radiance measurement of the scale-up prepared samples, the optimal Ba2＋ and Fe3＋ co-adding amount was determined to be 5%Ba2＋ plus 10%Fe3＋. Moreover, the infrared emissivity of the optimal composition at 100 ℃ was found to be higher than 0.8 in a wide wavelength range of 5-24μm. The research work demonstrates a promising application of Ba2＋/Fe3＋ cordierite solid solution as a kind of infrared heating materials for energy saving.

Movement-assisted service composition optimization in dynamic networks

The mobility of service providers brings new features into the research of dynamic network based service composition.From an optimistic perspective,the mobility of services could benefit the optimization of service composition,if properly handled.Therefore,the impacts of node mobility on the dynamic network based service composition are investigated.Then,a movement-assisted optimization method,namely MASCO,is proposed to improve the performance of the composited services by minimizing the length of data stream and the hop-counts of the service routes in the underlying networks.The correctness and efficiency of the proposed method are then verified through theoretical analysis and computer simulations.

A novel hybrid algorithm based on a harmony search and artificial bee colony for solving a portfolio optimization problem using a mean-semi variance approach

Portfolio selection is one of the major capital allocation and budgeting issues in financial management, and a variety of models have been presented for optimal selection. Semi-variance is usually considered as a risk factor in drawing up an efficient frontier and the optimal portfolio. Since semi-variance offers a better estimation of the actual risk portfolio, it was used as a measure to approximate the risk of investment in this work. The optimal portfolio selection is one of the non-deterministic polynomial(NP)-hard problems that have not been presented in an exact algorithm, which can solve this problem in a polynomial time. Meta-heuristic algorithms are usually used to solve such problems. A novel hybrid harmony search and artificial bee colony algorithm and its application were introduced in order to draw efficient frontier portfolios. Computational results show that this algorithm is more successful than the harmony search method and genetic algorithm. In addition, it is more accurate in finding optimal solutions at all levels of risk and return.

H形钢翼缘间填充混凝土的部分组合梁抗震性能试验研究

通过改进部分组合梁的系杆配置,设计了2个部分组合梁,研究了该梁在纯弯与剪弯受力状态下的滞回性能,分析了部分组合梁的承载能力、变形能力及耗能能力。试验结果表明:部分组合梁的受压翼缘在弹性阶段内没有屈曲,混凝土的存在提高了受压翼缘的屈曲承载力;部分组合梁在往复加载条件下滞回性能类似于钢梁,其滞回曲线较为饱满,捏缩现象不明显;试验骨架曲线与单调曲线较为吻合,混凝土压溃与剥落会引起部分组合梁的承载能力下降;部分组合梁的试验实测承载能力与采用边缘屈服准则及全截面塑性准则计算得到的理论值较为接近,采用以上两种准则来估计类似截面配置的部分组合梁的承载力是可行的;试件的转角延性系数在4~5之间,耗能系数在2.5左右,表明部分组合梁具有较好的抗震性能。

An adaptive over/under data combination method

The traditional ＂dephase and sum＂ algorithms for over/under data combination estimate the ghost operator by assuming a calm sea surface. However, the real sea surface is typically rough, which invalidates the calm sea surface assumption. Hence, the traditional ＂dephase and sum＂ algorithms might produce poor-quality results in rough sea conditions. We propose an adaptive over/under data combination method, which adaptively estimates the amplitude spectrum of the ghost operator from the over/under data, and then over/under data combinations are implemented using the estimated ghost operators. A synthetic single shot gather is used to verify the performance of the proposed method in rough sea surface conditions and a real triple over/under dataset demonstrates the method performance.

Automatic Web services composition algorithm based on optimal matching

A novel layered method was proposed to solve the problem of Web services composition.In this method,services composition problem was formally transformed into the optimal matching problem of every layer,then optimal matching problem was modeled based on the hypergraph theory,and solved by computing the minimal transversals of the hypergraph.Meanwhile,two optimization algorithms were designed to discard some useless states at the intermediary steps of the composition algorithm.The effectiveness of the composition method was tested by a set of experiments,in addition,an example regarding the travel services composition was also given.The experimental results show that this method not only can automatically generate composition tree whose leaf nodes correspond to services composition solutions,but also has better performance on execution time and solution quality by adopting two proposed optimization algorithms.

An Equation of Stirling Numbers of the Second Kind

In this paper, We propose and prove the following equation, where {3^n} is a stirling number of the second kind, when n ≥ 3 is given.

Distribution of Polychaete Assemblage in Relation to Natural Environmental Variation and Anthropogenic Stress

Polychaete are diverse species of the soft-bottom community, and are often used as indicators in environment monitoring programs. However, the effects of anthropogenic activities and natural environmental variation on polychaete assemblage are rarely addressed. The goals of this study are to identify the effects of natural environmental variation and anthropogenic stress on poly- chaete assemblage, and to explore the relationship between the polychaete assemblage structure and anthropogenic stress without considering the natural environmental variation. Based on the data collected from the surveys conducted in the tidal fiat of Jiaozhou Bay, the relationship between polychaete assemblage structure and environmental variables was determined using multivariate statis- tical methods including hierarchical cluster analysis, multidimensional scaling （MDS） and canonical correspondence analysis （CCA）. The results showed that the polychaete assemblage was dominated by two species, Amphictenejaponica and Heteromastusfiliformis, and could be divided into two subgroups characterized by high and low species abundance. CCA illustrated that the natural environ- mental variables including water temperature and the distance from coast had primary effects on the polychaete assemblage structure; while stress of contaminants, such as As and Hg, had the secondary influences; and stress from the aquacultured species, mainly Ruditapes philippinarum, had a limited effect. Colinearity between the natural environmental variables and anthropogenic stress variables caused a critical divergence in the interpretation of CCA results, which highlighted the risk of a lack of information in en- vironment assessment. Glycinde gurjanovae, Sternaspis scutata and Eulalia bilineata may serve as the ＇contamination indicators＇, which need to be confirmed in future studies.

Optimization of MQAM Modulation Schemes in Mobile Communications(Ⅰ)——Analysis of MQAM BER Performance in AGWN Channel Based on Signal Space

Based on signal space concepts, a transmission error code performance for MPSK, square MQAM and star MQAM modulation schemes on the AGWN channel is analyzed. The corresponding BER formulas and computer aided numeric results are also given. Therefore it provides a theoretical basis for choosing MQAM modulation schemes in mobile communications.

Constructing Pandiagonal Snowflake Magic Squares of Odd Order

The constructional methods of pandiagonal snowflake magic squares of orders 4m are established in paper [3]. In this paper, the constructional methods of pandiagonal snowflake magic squares of odd orders n are established with n = 6m+l, 6m+5 and 6m+3, m is an odd positive integer and m is an even positive integer 9|6m + 3. It is seen that the number sets for constructing pandiagonal snowflake magic squares can be extended to the matrices with symmetric partial difference in each direction for orders 6m + 1 , 6m + 5; to the trisection matrices with symmetric partial difference in each direction for order 6m + 3.

Nonlinear combined forecasting model based on fuzzy adaptive variable weight and its application

In order to enhance forecasting precision of problems about nonlinear time series in a complex industry system,a new nonlinear fuzzy adaptive variable weight combined forecasting model was established by using conceptions of the relative error,the change tendency of the forecasted object,gray basic weight and adaptive control coefficient on the basis of the method of fuzzy variable weight.Based on Visual Basic 6.0 platform,a fuzzy adaptive variable weight combined forecasting and management system was developed.The application results reveal that the forecasting precisions from the new nonlinear combined forecasting model are higher than those of other single combined forecasting models and the combined forecasting and management system is very powerful tool for the required decision in complex industry system.

A Composite Service Provision Method Based on Novel Node Model in Mobile Ad Hoc Networks

Composite service provision in mobile ad hoc networks encounters great challenges and its success rate is not satisfactory because the nodes' locations are dynamic and the nodes maybe unavailable at any time.Composite service is built through the service composition.In mobile ad hoc networks,the factors influencing the success rate of service composition are mainly the number of nodes and the time spent for the composition.The node's failure probability is proportional to the length of time the node exist in the networks.In order to improve the success rate of service composition,we take several measures.First,we split the service requirement into several segments and cluster the nodes,so that the nodes' waiting time for service composition can be reduced.Second,we propose a new node model of "one node contains multiple services" in mobile ad hoc networks.Using this type of nodes model,the number of nodes required for service composition can be reduced.These means can increase the success rate of service composition.

Optimization of MQAM Modulation Schemes in Mobile Communications(Ⅱ)——Analysis of MQAM BER Performance in Rayleigh Channel

the transmission error coed performance of square MQAM and starMQAM modulation schemes for the AGWN Rayleigh fading channel isanalyzed. The corresponding EBR formulas and computer aided numericresults are given. Therefore it provides a Theoretical basis forchoosing MQAM modulation schemes in mobile communications.

Combinatorial model of solute transport in porous media

Modeling of solute transport is a key issue in the area of soil physics and hydrogeology. The most common approach (the convection-dispersion equation) considers an average convection flow rate and Fickian-like dispersion. Here,we propose a solute transport model in porous media of continuously expanding scale, according to the combinatorics principle. The model supposed actual porous media as a combinative body of many basic segments. First, we studied the solute transport process in each basic segment body, and then deduced the distribution of pore velocity in each basic segment body by difference approximation, finally assembled the solute transport process of each basic segment body into one of the combinative body. The simulation result coincided with the solute transport process observed in test. The model provides useful insight into the solute transport process of the non-Fickian dispersion in continuously expanding scale.

China’s Growing Global Contributions

The UN Food and Agriculture Organization（FAO）awarded China on June 7,2015 for its share in reducing the global proportion of people suffering from hunger.China has witnessed remarkable achievements over the past three decades since the launch of its reform and opening-up policy.Rapid development of comprehensive national strength and a higher standard of living have laid a solid foundation for the country to assume more international responsibilities in accordance with its ability and world status.