基于约束的多量度静态路由算法

介绍了流量工程在Internet中的作用,以及流量工程中静态算法的地位.分析了当前静态路由算法研究现状并指出存在的缺点,由此提出一种新的可应用于流量工程的静态路由算法.该算法通过分析各服务质量需求,在算法运算过程中分阶段运用主次目标函数处理,从而满足流量工程中的服务质量需求,使网络资源得到充分利用.最后以编程仿真和理论推导两种方法论证了该算法的有效性、优越性.

多层次多量度分级权重的枢纽能力利用率评价

枢纽能力利用评价是铁路枢纽规划、总图设计的核心问题,其目的在于全面评价枢纽的能力利用状况,并找出制约能力发挥的关键要素。针对枢纽技术作业集中、高度专业化分工、作业关联性强的特点,采取按照评价对象设计评价指标的思路。将枢纽划分为客运、货运、行车、编解等子系统,将列流径路通畅性、点线能力协调性、编解负荷均衡性等作为评价指标,构建评价指标-评价对象-子系统及其元素-指标项的多系统多层次的指标体系。针对指标体系中各指标项的能力利用特征,设计指标项的能力利用率、负荷性、合理性等多种量度。以枢纽运输作业量为基础设置多层次权重体系,能有效避免主观权重对评价结果的影响,提出基于多层次、多量度、分层权重的枢纽能力利用率评价方法。针对郑州铁路枢纽能力利用率的实际算例进行评价,结果显示该枢纽能力利用率和能力负荷值总体水平较为适中,但枢纽能力分布的合理性有所不足,编组站对枢纽能力具有决定性影响,其中驼峰解体作业环节是枢纽整体能力利用较为突出的瓶颈位置。评价方法能从整体的角度全面、有效评价枢纽能力利用状况,避免了以往枢纽作业评价指标过于碎片化、评价方法难以摆脱主观因素干扰的弊端。

基于微藻多量度指标法提高河流和湖泊生物学状态评价准确性的研究进展

多量度指标(multimetric index,MMI)是一种广泛应用于淡水生态系统生态评价的方法,它能综合各种与生态有关的量度信息,并为进一步评价和管理提供一个易于理解的分值.准确评估淡水生态系统的生物学状态必须扣除自然变异的影响和解决自然环境因子与人为干扰因子之间的协变问题.最近几年,研究人员在上述两个方面取得了诸多进展.当下主要利用三种方法提高湖泊和溪流生物评价的准确性:按生态区或藻类物种组成对样点进行建模前分类、对样点的参考状态进行样点特异性建模分析和在不同的分组中采用不同的量度指标.所有已有的研究结果都支持对样点进行特异性建模法可以有效地扣除自然变异的影响,并最终通过模型计算出具有良好表现的MMI.然而,在扣除湖泊或河流中的自然变异方面,目前没有足够的证据表明依据硅藻/蓝藻物种组成的样点分类法优于依据生态区的分类法.另外,区分对样点特异性建模法和在不同样点组中采用不同量度指标法所解释的自然变异百分数,对于全面、准确地评价按藻类物种组成进行样点分组方法的作用是十分必要的.在不同样点组中使用不同量度指标法在溪流和湖泊中的表现不同,这很可能是由于硅藻量度指标对溪流和湖泊的生物学状态代表性不足,而不是由溪流和湖泊中复杂的多重胁迫因子造成的.本文的目的是回顾近年来利用藻类的MMI分析方法在确定湖泊和河流生物学状态方面的研究进展,以及在比较MMI表现过程中应注意的一些统计学问题.

Multiple attribute decision making method based on trapezoid fuzzy linguistic variables

The problem of multiple attribute decision making under fuzzy linguistic environments, in which decision makers can only provide their preferences （attribute values）in the form of trapezoid fuzzy linguistic variables（TFLV）, is studied. The formula of the degree of possibility between two TFLVs is defined, and some of its characteristics are studied. Based on the degree of possibility of fuzzy linguistic variables, an approach to ranking the decision alternatives in multiple attribute decision making with TFLV is developed. The trapezoid fuzzy linguistic weighted averaging （TFLWA） operator method is utilized to aggregate the decision information, and then all the alternatives are ranked by comparing the degree of possibility of TFLV. The method can carry out linguistic computation processes easily without loss of linguistic information, and thus makes the decision results reasonable and effective. Finally, the implementation process of the proposed method is illustrated and analyzed by a practical example.

A study of perfectly matched layers for joint multicomponent reverse-time migration

Reverse-time migration in finite space requires effective boundary processing technology to eliminate the artificial truncation boundary effect in the migration result.On the basis of the elastic velocity-stress equations in vertical transversely isotropic media and the idea of the conventional split perfectly matched layer（PML）,the PML wave equations in reverse-time migration are derived in this paper and then the high order staggered grid discrete schemes are subsequently given.Aiming at the＂reflections＂from the boundary to the computational domain,as well as the effect of seismic event＇s abrupt changes at the two ends of the seismic array,the PML arrangement in reverse-time migration is given.The synthetic and real elastic,prestack,multi-component,reverse-time depth migration results demonstrate that this method has much better absorbing effects than other methods and the joint migration produces good imaging results.

Fabricating a Micro Electromagnetic Actuator with High Energy Density

This paper introduces a new technology to fabricate a micro electromagnetic actuator with high energy density without an enclosed magnetic circuit. This technology includes fabricating multi-turns planar micro coils and fabricating the thick magnetic （NiFe） core on the silicon wafer. The multi-turns planar micro coils are fabricated by the electroplating method from the surface along the line and by dynamically controlling the current density of the copper electrolytes. In order to fabricate thick NiFe plating,the adhesion properties between the NiFe plating and the silicon substrates are improved by changing the surface roughness of the silicon substrates and increasing the thickness of the seed layer. Furthermore,the micro electromagnetic actuator is tested and the energy density of the actuator is evaluated by force testing. The experiments show that the microactuator is efficient in producing high magnetic energy density and high magnetic force.

Mathematically modeling the main dimensions of self-elevating drilling units

The present status of self-elevating drilling units was analysed. Based on statistics of the main dimensions of self-elevating drilling units, a mathematical model was established using stepwise return procedures and a back-propagation neural network. mathematical model is applicable and reliable. The of the main dimensions of self-elevating drilling Analysis of examples of calculations showed that the model is useful for mastering the essential variations units and can be used for technical and economic analysis as well as in conceptual designs of drilling units.

MULTIVARIATE ABSOLUTE DEGREE OF GREY INCIDENCE BASED ON DISTRIBUTION CHARACTERISTICS OF POINTS

The analysis result of absolute degree of grey incidence for multivariate time series is often inconsistent with the qualitative analysis. To overcome this shortage, a multivariate absolute degree of grey incidence based on distribution characteristics of points is proposed. Based on the geometric description of multivariate time se- ries, the neighborhood extrema are extracted in the different regions, and a characteristic point set is constructed. Then according to the distribution of the characteristic point set, a characteristic point sequence reflecting the ge- ometric features of multivariate time series is obtained. The incidence analysis between multivariate time series is transformed into the relational analysis between characteristic point sequences, and a grey incidence model is established. The model possesses the properties of translational invariance, transpose and rank transform invari- ance, and satisfies the grey incidence analysis axioms. Finally, two cases are studied and the results prove the ef- fectiveness of the model.

Effect of Cr content on microstructure and properties of aged Cu−Cr−P alloys

The role of Cr in affecting the precipitates and the properties of aged Cu−Cr−P alloys was investigated and discussed.The results show that there are mainly three sizes of Cr phase in aged Cu−Cr−P alloys,among them,the nano-sized Cr phase plays an important role in the strength of Cu−Cr−P alloys.The strengthening effect of Cr phase(less than 5 nm)with FCC structure completely coherent with the matrix is calculated to be about 200 MPa on the basis of dislocation cut-through mechanism.The strengthening effect of Cr phase(10−20 nm)with BCC structure incoherent with the matrix is calculated to be about 100 MPa on the basis of the Orowan dislocation bypass mechanism.The increase of Cr content changes the number and size of nano-sized Cr phase,which causes the mechanical properties of the Cu−Cr−P alloys to increase first and then decrease.The tensile strength of Cu−0.36Cr−0.01P alloy is 572 MPa and its electrical conductivity is 80%IACS after solid solution treatment at 980°C for 2 h followed by 95%cold rolling and then aging treatment at 450°C for 1 h.

Error Analysis and Accuracy Assessment of GPS Absolute Velocity Determination without SA

Error sources which decrease the accuracy of GPS in absolute velocity determination have been changed since SA was turned off. Firstly, quantities of all kinds of error sources that influence velocity deter-mination are analyzed. The potential accuracy of GPS absolute velocity determination is derived from both theory and field GPS data simulation. After that, two tests were carried out to evaluate the performance of GPS absolute velocity determination in the case of a static and an airborne GPS receiver and INS (Inertial Navigation System) instrument in kinematic mode. In static mode, the receiver velocity has been estimated to be several mm/s with the carrier-phase derived Doppler measurements, and several cm/s with the receiver generated Doppler measurements. In kinematic mode, GPS absolute velocity estimates are compared with the synchronized measurements from the high accuracy INS. The root mean square statistics of the velocity discrepancies between GPS and INS come up to dm/s. Moreover, it has a strong correlation with the accel-eration or jerk of the aircraft.

Design of similarity measure for discrete data and application to multi-dimension

Similarity measure design for discrete data group was proposed. Similarity measure design for continuous membership function was also carried out. Proposed similarity measures were designed based on fuzzy number and distance measure, and were proved. To calculate the degree of similarity of discrete data, relative degree between data and total distribution was obtained. Discrete data similarity measure was completed with combination of mentioned relative degrees. Power interconnected system with multi characteristics was considered to apply discrete similarity measure. Naturally, similarity measure was extended to multi-dimensional similarity measure case, and applied to bus clustering problem.

Optical Fiber Instrument for Single-point Multi-parameter Measurement

A novel kind of optical fiber instrument for two channel measurement of temperature and displacement was developed. Four channel quartz fiber optics were employed to measure two channel signals of temperature and displacement simultaneously, and the operating efficiency of this instrument was greatly improved.

On some projectively flat polynomial (α,β)-metrics

In this paper, we consider some polynomial （a,fl）-metrics, and discuss the sufficient and necessary conditions for a Finsler metric in the form F=α＋α1β＋α2β^2/α＋α4β^4/α^3 to be projectively flat, where ai 0=1,2,4） are constants with a1≠0, a is a Riemannian metric and β is a 1-form. By analyzing the geodesic coefficients and the divisibility of certain polynomials, we obtain that there are only five projectively flat cases for metrics of this type. This gives a classification for such kind of Finsler metrics.

Distributed Optical Fiber Sensor for Multi-point Temperature Measurement

The distributed optical fiber sensing technology is overviewed,which is based on Raman scattering light theory.Basic operation principle,structure,system characteristics and signal processing are discussed.This structure and method of the signal processing possess of certain spatial resolution,hence will ensure the practicability of system.

Patient and physician perception of natural orifice transluminal endoscopic appendectomy

AIM:To investigate perception of natural orifice transluminal endoscopic surgery(NOTES)as a potential technique for appendectomy.METHODS:One hundred patients undergoing endoscopy and 100 physicians were given a questionnaire describing in detail the techniques of NOTES and laparoscopic appendectomy.They were asked about the reasons for their preference,choice of orifice,and extent of complication risk they were willing to accept.RESULTS:Fifty patients(50%)and only 21 physicians(21%)preferred NOTES(P<0.001).Patients had previously heard of NOTES less frequently(7%vs73%,P<0.001)and had undergone endoscopy more frequently(88%vs 36%,P<0.001)than physicians.Absence of hernia was the most common reason for NOTES preference in physicians(80%vs 44%,P= 0.003),whereas reduced pain was the most common reason in patients(66%vs 52%).Physicians were more likely to refuse NOTES as a novel and unsure technique(P<0.001)and having an increased risk of infection(P<0.001).The preferred access site in both groups was colon followed by stomach,with vagina being rarely preferred.In multivariable modeling,those with high-school education[odds ratio(OR):2.68,95% confidence interval(CI):1.23-5.83]and prior colonoscopy(OR:2.10,95%CI:1.05-4.19)were more likely to prefer NOTES over laparoscopic appendectomy.There was a steep decline in NOTES preference with increased rate of procedural complications.Male patients were more likely to consent to their wives vaginal NOTES appendectomy than male physicians(P=0.02).CONCLUSION:The preference of NOTES for appendectomy was greater in patients than physicians and was related to reduced pain and absence of hernia rather than lack of scarring.

Modeling and monitoring of nonlinear multi-mode processes based on similarity measure-KPCA

A new modeling and monitoring approach for multi-mode processes is proposed.The method of similarity measure(SM) and kernel principal component analysis(KPCA) are integrated to construct SM-KPCA monitoring scheme,where SM method serves as the separation of common subspace and specific subspace.Compared with the traditional methods,the main contributions of this work are:1) SM consisted of two measures of distance and angle to accommodate process characters.The different monitoring effect involves putting on the different weight,which would simplify the monitoring model structure and enhance its reliability and robustness.2) The proposed method can be used to find faults by the common space and judge which mode the fault belongs to by the specific subspace.Results of algorithm analysis and fault detection experiments indicate the validity and practicability of the presented method.

Energy-efficient data transmission with non-ideal circuit power for downlink cellular networks

The downlink energy-efficient transmission schedule with non-ideal circuit power over Wreless networks involving a single transmitter and multiple receivers was investigated. According to the special structure of the problem, a novel algorithm called OOSCPMR （the optimal offine scheduling with non-ideal circuit power for multi-receivers） is proposed, and the optimal offine solutions to optimize the energy- efficient transmission policy are found. The packets to be transmitted can be divided into two types where one type of packet is determined to be transmitted using the enrgy- efficient tansmission time, and the other type of packet is determined by the ID moveright algorithm. Finally, an energy-efficient online schedule is developed based on te proposed OOSCPMR algoriAm. Simulation results show that the optima offline transmission schedule provides te lower bound performance for the online tansmission schedule. The proposed optimal offline and online policy is more energy efficient than the existing schemes tat assume ideal circuit power.

Metrics analysis of tactile perceptual space based on improved NMDS for leather textures

To solve the fuzzy and unstable tactile similarity relationship between some sample points in the perception experiment,an improved non-metric multidimensional scaling(INMDS)is proposed in this paper.In view of the inconsistency of each sample s contribution,the maximum marginal decision when constructing the perception space to describe the tactile perception characteristics is also proposed.The corresponding constraints are set according to the degree of similarity,and controlling the relaxation variable factor is proposed to optimize the perception dimension and coordinate measurement.The effectiveness of the INMDS algorithm is verified by two perception experiments.The results show that compared with the metric multidimensional scaling(MDS)and non-metric multidimensional scaling(NMDS)algorithms,the perceptual space constructed by INMDS can more accurately reflect the difference relationship between different leather sample points perceived by people.Moreover,the relative position of sample points in the perceptual space is more consistent with subjective perception results.

Reliability analysis of structure with random parameters based on multivariate power polynomial expansion

A new method for calculating the failure probabilityof structures with random parameters is proposed based onmultivariate power polynomial expansion, in which te uncertain quantities include material properties, structuralgeometric characteristics and static loads. The structuralresponse is first expressed as a multivariable power polynomialexpansion, of which the coefficients ae then determined by utilizing the higher-order perturbation technique and Galerkinprojection scheme. Then, the final performance function ofthe structure is determined. Due to the explicitness of theperformance function, a multifold integral of the structuralfailure probability can be calculated directly by the Monte Carlo simulation, which only requires a smal amount ofcomputation time. Two numerical examples ae presented toillustate te accuracy ad efficiency of te proposed metiod. It is shown that compaed with the widely used first-orderreliability method （ FORM） and second-order reliabilitymethod （ SORM）, te results of the proposed method are closer to that of the direct Monte Carlo metiod,and it requires much less computational time.

Mechanochemical degradation of potato starch paste under ultrasonic irradiation

In the paper, changes in the molecular weight, the intrinsic viscosity and the polydispersity (molecular mass distribution) of treated potato starch paste were studied under different ultrasonic conditions which include irradiation time, ultrasonic intensity, potato starch paste concentration, and distance from probe tip on the degradation of potato starch paste. Intrinsic viscosity of potato starch paste was determined following the ASTM (American Society for Testing and Materials) standard practice for dilute solution viscosity of polymers. Molecular mass and polydispersity of potato starch paste were measured on GPC (Gel Permeation Chromatography). The results showed that the average molecular mass and the intrinsic viscosity of starch strongly depended on irradiation time. Degradation increased with prolonged ultrasonic irradiation time, and the increase of ultrasonic intensity could accelerate the degradation, resulting in a faster degradation rate, a lower limiting value and a higher degradation extent. Starch samples were degraded faster in dilute solutions than in concentrated solutions. The molecular mass and the intrinsic viscosity of starch increased with the increase of distance from probe tip. Our results also showed that the polydispersity decreased with ultrasonic irradiation under all ultrasonic conditions. Ultrasonic degradation of potato starch paste occured based on the mechanism of molecular relaxation of starch paste. In the initial stage, ultrasonic degradation of potato starch paste was a random process, and the molecular mass distribution was broad. After that, ultrasonic degradation of potato starch paste changed to a nonrandom process, and the molecular mass distribution became narrower. Finally, molecular mass distribution tended toward a saturation value.