广义Ky-Fan’s极大极小不等式理论

将Ky-Fan’s极大极小不等式理论推广,得到广义Ky-Fan’s极大极小不等式。     

消息对Pollard’s rho搜索算法设计

MD5选择前缀碰撞攻击可应用于伪造CA证书等实际攻击中,构造MD5选择前缀碰撞对是攻击MD5的一个重要研究课题。构造MD5选择前缀碰撞消息对时,需要利用高性能计算设 备搜索(0,δb,δc,δc,) 消息对,文章用概率方法描述了生日攻击的原理,阐述了利用生日攻击思想搜索(0,δb,δc,δc,) 消息对的Pollard’s rho 算法和并行Pollar d’s rho算法,分析了算法的复杂度,最后给出了一组实验数据。。     

Chen’s系统混沌行为负反馈控制

研究了Chen’s系统的非线性动力学行为及稳定性，采用负反馈控制方法对Chen’s系统的混沌行为进行控制，把该系统控制到指定的平衡态扣希望的振荡周期轨道上．并对控制方法的混沌控制过程进行理论分析与数值研究，得到了一致的结果。     

Prediction of a V-8 diesel engine’s structural radiated noise and research of important parameters’ effects on the engine’s acoustic behaviors

Based on the coupled boundary element method-finite element method(BEM-FEM)method and the acoustic transfer vector(ATV)technology,BEM/FEM model is proposed for a V-type eight cylinders engine acoustic radiation simulating analysis under semi-anechoic condition.Acoustic radiation power,field points sound pressure level and panel contributions are calculated by acoustic radiation response analysis.Additionally,based on the engine acoustic performance,different acoustic behaviors of engine are studied by changing engine materials,oil pan structures as well as geometry parameters.The acoustic performance of this engine is predicted and the influence of material,structural and geometry parameters on engine radiated noise are generalized.The principle will guide the design and optimization of the engine prototype in further work.     

Spectral-domain dyadic Green’s functions in chiral media

A novel method of deriving the electromagnetic dyadic Green’s functions in an unbounded, lossless, reciprocal and homogeneous chiral media described by the constitutive relations D=εE+jγB and H=jγE+μ-1B-(ωε)-1γJ is given. The divergenceless and irrotational splitting of dyadic Dirac δ function and Fourier transformation are used to directly obtain the divergenceless and irrotational component of spectral-domain dyadic Green’s functions in chiral media. This method avoids using the dyadic Green’s function eigenfunction expansion technique. The method given here can be generalized to a source-free region and an achiral case.     

Kinematic and Dynamic Characteristics Analysis of Bennett’s Linkage

Bennett’ s linkage is a spatial fourlink linkage, and has an extensive application prospect in the deployable linkages.Its kinematic and dynamic characteristics analysis has a great significance in its...     

Density-functional-theory formulation of classical and quantum Hooke’s law

A fundamental property of solid materials is their stress state. Stress state of a solid or thin film material has profound effects on its thermodynamic stability and physical and chemical properties. The classical mechanical stress(δM) originates from lattice strain(m), following Hooke's law: δM=Cδ, where C is elastic constant matrix. Recently, a new concept of quantum electronic stress(δ QE) is introduced to elucidate the extrinsic electronic effects on the stress state of solids and thin films, which follows a quantum analog of classical Hooke's law: QE=δ(δn), where δis the deformation potential of electronic states and n is the variation of electron density. Here, we present mathematical derivation of both the classical and quantum Hooke's law from density functional theory. We further discuss the physical origin of quantum electronic stress, arising purely from electronic excitation and perturbation in the absence of lattice strain(ε=0), and its relation to the degeneracy pressure of electrons in solid and their interaction with the lattice.     

Modeling electric vehicle’s following behavior and numerical tests

The micro modeling for electric vehicle and its solution were investigated. A new car-following model for electric vehicle was proposed based on the existing car-following models. The impacts of the electric vehicle＇s charging electricity were studied from the numerical perspective. The numerical results show that the electric vehicle＇s charging electricity will destroy the stability of uniform flow and produce some prominent queues and these traffic phenomena are directly related to the initial headway, the distance between two adjacent charging stations and the number of charging stations. The above results can help traffic engineer to choose the position of charging station and the electric vehicle＇s driver to adjust his/her driving behavior in the traffic system with charging station.     

Three dimensional simulation of electromagnetic railgun’s exterior ballistics

In order to evaluate the electromagnetic railgun＇ s practical combat capability as well as its tactic application prospects, a three dimensional simulation model of electromagnetic railgun＇ s exterior ballistics is presented. On the hypothesis of the Earth＇ s being round and ignoring the influ- ence of rotation, the railgun＇ s atmospheric environment and its motion equations are established by the Simulink Module of Matlab. And the railgun＇ s characteristics of exterior ballistic under different muzzle energy and emission inclinations are discussed. Results show that its incomparable superiori- ty in improving range and lethality to conventional artillery under the same launch condition based on railgun＇ s range and variation of velocities. It is useful for the efficacy evaluation of railgun＇ s combat capability and its practical applications in fields such as ground war, missile interception and so on.     

Biological analysis of woodpecker’s brain after impact experiments

Woodpeckers can withstand a fierce impact during pecking. Previous studies have focused on the biomechanical analysis of the pecking process, the properties of the beak and hyoid bone of woodpecker; however, the biological characteristics of the woodpecker brain are also important in resisting impact injuries. We employed impact experiments and biological analysis in normal and injured brains to reveal the impact-resistant biological characteristics of woodpecker brains, as well as the impact energy's biological effects on the woodpecker brain. The hoopoe, which has a similar size but only a slight pecking behavior, was selected as the control group to compare brain morphology and neuronal cells differences in normal brains between woodpecker and hoopoe by sectioning and staining. A loading device was designed to conduct a quantifiable impact energy to the woodpeckers' head. Four groups of woodpeckers were impacted with the same energy on the forehead, beak, tempus and occiput,respectively. Biological changes in the injured brains were evaluated by Nissl staining and enzyme-linked immunosorbent assay.The results showed that:(1) woodpeckers had a larger cerebellum and a higher density of Nissl bodies than hoopoe;(2) Nissl apoptosis appeared in the brain samples after the forehead and the occiput impact experiments, but no obvious Nissl body apoptosis was observed after impact on the tempus and the beak;(3) β-amyloid protein accumulated in the normal status woodpecker brain. This study reveals that: woodpecker brain morphology is well-adapted to impact, woodpecker heads display location-dependent protective performance, with beak and tempus regions having a better protective performance than the forehead and occiput, Nissl apoptosis appears in injured woodpecker brains, and that the accumulation of β-amyloid protein does not show a direct relationship with the injury state of woodpecker's brain tissue in our study.     

Identification of traffic object’s motion behavior based on track

To extract the track parameters of a traffic object in traffic video and identify its motion behavior,a new method is proposed based on CamShift(Continuously Adaptive Mean Shift)and HMM(Hidden Markov Model).First,an object entering the video scene is located and tracked by the CamShift based algorithm,then its track parameters are obtained.Next,the track parameters are processed to form the observation sequence of HMM,and the motion behavior modeling and probability evaluation are implemented based on HMM.At last,the behavior identification and behavior statistics of the tracked traffic object in video are achieved.Experiments show that this method can be used to sort and recognize the motion behavior of the traffic object by its corresponding behavior track,and to do some statistics or corresponding process schemes.     

User’s Relevance of PIR System Based on Cloud Models

Information retrieval (IR) is to find by usingrelevant technology a set of relevant documents to us-er’s queries froma large number of documents . Thisset includes a certain number of documents , whichinclude non-relevant documents asless as possible .Inother words ,the major taskinIRistorealize the rel-evance judgements to query. Relevance is one of thekey concepts in IR.User’s relevanceis some kind of applicabilityforone document to a special user . Documents take onrandomicity and unce…     

Student’s t滤波框架下的信息融合算法

针对多传感器系统的观测噪声为非高斯噪声的问题,通过Student’s t滤波框架和四元数特性相结合,以无迹变换计算Student’s t加权积分函数,设计基于Student’s t分布的无迹四元数滤波算法,作为局部滤波算法. 利用拉格朗日乘子法计算最优融合权重系数,通过线性加权融合的方式,对各局部滤波结果进行融合. 采用基于四元数的目标姿态运动模型进行仿真,利用3个星敏感器同时对同一目标进行观测,通过与已有的鲁棒无迹Student’s t滤波（RSTUF）算法对比,验证所提算法的有效性. 仿真结果表明：所提算法在对目标姿态的估计精度、滤波收敛速度及收敛后的数值稳定性方面均高于RSTUF算法;通过多个观测信息互补,提高了估计精度及容错性.     

Simulation of Cobalt-Rich Crust’s Crushing Process Based on ANSYS

1 Introduction There are hundreds of millions tons of cobalt- rich crust which contain many metal elements such as cobalt, nickel, silver, copper, gold, platinum and thu- lium on the seabed. Because of its practically strate- gic, economic and political significance, cobalt-rich crust has become a great concern in ocean resource exploitation for every country [1–2]. The business mining system of cobalt-rich crust will probably con- sist of the mining subsystem, lifting subsystem, telemetering…     

Generalization of Hill’s yield criterion to tension-compression asymmetry materials

This paper is devoted to developing a yield criterion that can model the asymmetry and anisotropy in yielding of pressure insensitive metals,in terms of accuracy and simplicity of formulation.First,a new isotropic yield criterion,which can model the asymmetry in yielding of pressure insensitive metals,is proposed.Further,using Cazacu’s generalizations to anisotropic conditions of the invariants of the deviatoric stress,the proposed isotropic yield criterion is extended to orthotropy.The proposed anisotropic criterion has a quite simple form,and the number of material constants involved is only half of that of Cazacu’s(2004) yield criterion.Compared to Hill’s(1948) yield criterion,the proposed anisotropic yield criterion has three additional constants,which are used to model the tension-compression asymmetry of materials.All the material constants involved in the criterion can be determined by simple tests.The proposed criterion reduces to Hill’s(1948) yield criterion if the tensile and compressive yield stresses are equal.In other words,the proposed anisotropic yield criterion can be considered as an extension of Hill’s(1948) criterion to tension-compression asymmetry materials.The anisotropic yield criterion is used to describe the plastic response of Cu-Al-Be shape memory alloy(data after Laydi and Lexcellent) and Ni3Al based intermetallic alloy IC10 sheets.It is shown that the proposed yield criterion can describe very well the asymmetry and anisotropy observed in those materials.     

Application of modified banker’s algorithm in FMS deadlock problem

Whendesignedandoperatedeffectively ,FMScanbeofassistancetomanufacturersaccordingtodefinedproduc tionandprocessplans ,whichspecifytheactivitiesandresourcesaswellassequencerelatedconditions ,suchasprecedencerelationsandsynchronization .Alternativere sourcesandroutingforsomeofthejobsinFMSmaybespecifiedpreviously .Thisresultsinanincreasingflexibil ityinjobscheduling .Someresourceallocationsmayleadtodeadlocksituations ,inparticularwhentheresourcesinsystemarelimited .Deadlockproblemscancauseunnec…     

User’s Relevance of PIR System Based on Cloud Models

A new method to evaluate fuzzily user＇s relevance on the basis of cloud models has been proposed. All factors of personalized information retrieval system are taken into account in this method. So using this method for personalized information retrieval （PIR） system can efficiently judge multi-value relevance, such as quite relevant, comparatively relevant, commonly relevant, basically relevant and completely non-relevant, and realize a kind of transform of qualitative concepts and quantity and improve accuracy of relevance judgements in PIR system. Experimental data showed that the method is practical and valid. Evaluation results are more accurate and approach to the fact better.     

Evaluation of TBM Cutterhead’s Comprehensive Performance Under Complicated Conditions

一种TBM刀盘综合性能评价方法在本文中提出。从强度和振动两个方面建立了评价体系,应用断裂力学以临界裂纹长度为标准,并提出了刀盘疲劳强度分区评价法,以更准确更具体的评价刀盘疲劳强度建立疲劳强度评价指标。此外,利用动力学方程,获取关键部位三向速度,以其速度均方根值作为振动烈度指标。最后以吉林引水工程TBM刀盘为例,对各指标进行计算,将计算结果与TBM刀盘振动检测数据进行对比,结果如下：刀盘加速度的理论计算结果与试验结果近似,证明振动指标计算方法是有效的,刀座焊接疲劳强度可靠度在掘进机工作时应予以重视,TBM刀盘的振动烈度满足要求,但有待提高。     

The revision on heat capacity of Einstein’s solid model

FromEinstein’s supposition aboutcrystal lattice vi-bration, which states that the vibration frequency of ev-ery crystal lattice is the same, the balance of heat ener-gy in the crystal can be written out using the theory ofstatistical thermodynamics, so that the molar heat capac-ity under normal temperatures can be easily calculated.For many kinds of metals, the theoretical value of themolar heat capacity is close to the experimental value.In other kinds of metals, though, especially metals of…