10 Gb/s transmitter-based equalization for extended-reach multimode-fiber datacommunication links

Transmitter-based equalization is investigated for enhanced performance in 10 Gb/s multimodefiber links. Rigorous simulations and proof-of-principle experiments over 500 m of FDDI-grade fiber confirm for the first time the potential superiority of the technique relative to receiver-based schemes. © 2007 Optical Society of America.

主成分分析和聚类分析在软件重构中的应用

重构是软件系统不断演化的关键之一,也是一项复杂而又困难的活动.传统的定位重构代码方法依赖开发者的观察和主观意识,耗时耗力,尤其在重构代码较多时.因此,提出了一套自动化定位重构的方法.该方法利用基于面向对象软件度量指标获取代码特征信息,使用相关性检验查验特征信息数据,应用主成分分析压缩和解释特征信息,应用聚类分析分类相似代码段,迅速准确定位重构.一个简单的实例表明该方法是简单有效的,并且优于传统方法.

卫星高度计资料在海洋潮汐研究中的应用

本文依据收集到的392个地面验潮站8个主要分潮（M2、S2、K1、O1、N2、K2、P1及Q1）的调和常数，对现有7个全球大洋潮汐模式的准确度进行了检验，结果显示各模式在深海区域均达到了比较高的准确度，相互之间差别也不大。经验模式GOT00和CSR4.0、同化模式NAO99、反演同化模式TPXO7.0、数值同化模式FES2002和FES2004的M2分潮均方根偏差在3 cm左右，其它分潮（S2、K1、O1、N2、K2、P1及Q1）大约在1～2 cm。本文还依据中国近海18个岛屿的调和常数对其中的5个大洋潮汐模式的准确度进行了检验，结果表明，M2分潮均方根偏差在6～14 cm，明显高于大洋部分的偏差，其中日本国家天文台的潮汐模式NAO99在中国近海的结果相对较准确。 我们利用1992年8月至2008年8月的TOPEX/POSEIDON和JASON-1(T/P-J)卫星高度计资料，对沿卫星轨道的302816个站点进行了14个分潮的潮汐调和分析，得到了全球大洋潮汐的8个主要分潮以及2个气象分潮Sa、Ssa的经验同潮图。主要结果有：（1）各分潮在卫星上升轨道与下降轨道的交叉点(约7000个)相关性分析表明：M2分潮的振幅和迟角的相关系数很高（分别为0.9965和0.9961）；S2，K1，O1和Sa分潮也有较好的相关性（相关系数为0.94～0.99）；（2）该结果与392地面个验潮站吻合较好，其中M2分潮的振幅、迟角和向量的均方根偏差分别为：1.73 cm，2.340和2.93 cm；S2，K1和O1分潮的振幅、迟角和向量的均方根偏差为1 cm左右，5.250～7.270和1.5～2.1 cm，该精度与最近几年国际上的主要大洋潮汐模式的准确度相近；（3）首次通过卫星资料获得了Sa、Ssa分潮的同潮图。周期为1年的Sa分潮与大洋105个地面站相比，振幅、迟角和向量的均方根偏差分别为1.50 cm、18.360和2.16 cm。在此基础上，进一步分析了构成Sa、Ssa气象分潮的两个主要因素（海水密度以及海面气压）在全球的分布。 在T/P-J等卫星资料无法覆盖到南大洋和北冰洋，本文利用Princeton Ocean Model（POM）进行了数值模拟，模拟结果与162个地面实测站（其中南大洋30个，北冰洋132个）的观测比较一致。基于卫星资料分析的结果和数值模拟结果合并得到了全球大洋的8个主要分潮同潮图。在此基础上通过全球潮汐能量耗散的计算得到潮能通量的分布，并得到全球M2、S2、K1和O1分潮的潮汐能量耗散率为2.431TW、0.401TW、0.336TW和0.176TW。 本文还利用卫星资料对南海潮汐进行了研究，在中国南海，获得了主要的半日潮、全日潮、四分日分潮和长周期分潮（M2，S2，N2，K2，K1，O1，P1，Q1，M4, MS4，Sa, Ssa）的经验同潮图。与南海沿岸94个地面验潮站的数据符合得比较好，M2，S2，K1及O1等4个主要分潮的平均振幅差为2～4 cm，均方根偏差分别是9～11 cm.其它4个主要分潮N2，K2，P1，Q1的平均振幅差为1～2 cm，均方根偏差为2～4 cm。此外，本文还利用卫星高度计资料潮汐分析结果沿卫星轨道进行高通滤波，分离得出中国近海的M2，S2，K1及O1分潮的内潮信息。

五轴磨抛机器人补偿算法研究与实现

通过分析基于模型的补偿方法和非模型补偿方法的优缺点,结合一个五轴磨抛机器人的结构特点,提出了两种补偿方法相结合的混合补偿算法.针对平移关节误差的主要来源难于建模的特点,采用非模型的方法进行补偿;针对转动关节误差主要来源为几何参数误差,能够建模,但有些参数随机器人末端位置不同而变化的特点,采用二者相结合的混合方法进行补偿.通过对该机器人系统的实验,验证了方法的有效性和可行性.

基于四自由度并联机构的数控机床研究

介绍一种基于混合型四自由度并联平台机构开发的五坐标并联机床 .由于其独特的机构设计 ,与基于 Stewart平台的并联机床相比 ,X方向的进给运动与运动平台分离 ,改由工作台单独进给 ,因而其工作空间成倍增大 .采用龙门框架结构和滚珠丝杠支承方案使机床获得更高的刚度 .给出了该机床运动学逆解 ,控制系统采用基于 PC的数控系统进行五轴联动控制

基于Stewart平台六维力传感器的分区静态标定方法

基于Stewart平台的六维力传感器具有结构紧凑、刚度大、量程宽等特点,它在工业机器人、空间站对接等领域具有广泛的应用前景。好的标定方法是正确使用传感器的基础。由于基于Stewart平台的六维力传感器是一个复杂的非线性系统,所以采用常规的线性标定方法必将带来较大的标定误差从而影响其使用性能。标定的实质是,由测量值空间到理论值空间的映射函数的确定过程。由函数逼近理论可知,当只在已知点集上给出函数值时,可用多项式或分段多项式等较简单函数逼近待定函数。基于上述思想,本文将整个测量空间划分为若干连续的子测量空间,再对每个子空间进行线性标定,从而提高了整个测量系统的标定精度。实验分析结果表明了该标定方法有效。

大型激光叠焊系统研究与开发

介绍一种新型激光叠焊系统,利用该系统可将尺寸范围为12.0m×1.5m厚度不等的两块不锈钢板重叠焊接在一起。针对大尺寸不锈钢板尺寸大、易变形等特点提出了主—辅式压紧机构,有效地控制了焊接过程中大尺寸板材的变形并消除了板材间隙;设计了ufxyz型四轴联动方案:u轴与x轴同向,u轴驱动钢板进行大范围运动,x轴驱动激光头小范围运动。u轴与x轴的复合运动提高系统精度的同时提高了系统焊接动态响应速度。对实际焊接板材进行试验验证,结果表明使用该系统进行焊接的钢板可承受压强最大能达到6.1MPa。

孤岛油田中二北区Ng3～6储层建筑结构与油水分布规律研究

The reservoir of Zhongerbei region in Gudao Oilfield is a typical fluvial facies deposit, its serious heterogeneity of the reservoir caused the distribution of remaining oil in mature reservoirs is characterized by highly scattered in the whole field, and result to declination of production, tap potential and stabilize production is more difficult. Reservoir modeling based on lay scale can not fulfill requirement. How to further studied reservoir heterogeneity within the unit and establish the finer reservoir modeling is a valid approach to oil developing. The architectural structure elements analysis is the effectively method to study reservoir heterogeneity. Utilize this method, divide the reservoirs of Gudao Oilfield into ten hierarchies. The priority studying is sixth, seven hierarchies, ie single sand layers sand bodies By the identification of sixth, seven hierarchies, subdivide the reservoir to the single genetic unit. And to subdivide by many correlation means, such as isometry and phase transition, accomplish closure and correlation of 453 wells.Connectting fluvial deposit pattern, deposition characteristic with its log, build the inverting relation between “sedimentary facies” and “electrofacies” The process emphasize genetic communication and collocation structure of genetic body in space. By detailed architecture analyses sandbodies’ structure, this paper recognize seven structure elements, such as major channel, abandoned channel, natural levee, valley flat, crevasse splay, crevasse channel and floodplain fine grain.Combination identification of architectural structure elements with facieology and study of deposition characteristic, can further knowing genesis and development of abandoned channel. It boost the accuracy to separation in blanket channel bodies distribution, and provide reference to retrieving single channel boundary. Finally, establish fine plane and section construction. On basis architectural structure map, barrier beds and interbeds isopach map and mini-structure map, considering single thin layers to be construction unit, the main layer planimetric maps have drawn and the inner oil-water boundary have revealed. All account that architectural structure elements control remaining oil distribution in layer, and develop the study on architectural structure elements to direct horizontal well is succesful.

土石混合体细观结构力学及其边坡稳定性研究

Soil-rock mixture (S-RM) refers to one extremely uneven loose rock and soil materials system with certain stone content. Its formation has started since Quaternary and it is composed of block stone, fine grained soil and pore with certain project scale and high strength. S-RM has extensive distribution in nature, especially in southwest China where the geotectonic background is complicated, the fracture activity is developed and the geomorphological characteristics of high mountain and steep gorge area are protuberant. This kind of complicated geologic body has developed wider in these areas. S-RM has obvious difference with the general soil or rock (rock mass) in physical and mechanical properties because its two components-“soil” and “rock-block” has extreme differences in physical and mechanical properties. The proposition of S-RM and its deep research are needed in the modern engineering construction. It is also the necessity in the modern development of rock and soil mechanics. The dissertation starts from the meso-structural characteristics of soil-rock and takes a systematic research on its meso-structural mechanics, deformation and failure mechanism and the stability of S-RM slope. In summary, it achieves the following innovative results and conclusions. There are various views on the conception of S-RM and its classification system. Based on the large number of field tests, the dissertation makes the conception and classification of S-RM more systematic. It systematically proposed the conception of meso-structural mechanics of S-RM. Thus the dissertation has laid a foundation for its deep study. With the fast development of the computer technology and digital image processing theory, digital image processing technology has been successfully applied in many fields and provided reliable technology support for the quantitative description of the structural characteristics of S-RM. Based on the digital image processing technology, the dissertation systematically proposes and developed the quantitative analysis method and quantitative index for the meso-structure of S-RM. The results indicate that the meso-structure such as its internal soil-rock granularity composition, the soil-rock shape and the orientability has obvious self-organization in the macro statistical level. The dissertation makes a systematic research on the physical mechanical properties, deformation and failure mechanism of S-RM based on large field test. It proposes the field test for the underwater S-RM and deduces the 3D data analysis method of in-situ horizontal push-shear test. The result indicates that S-RM has significant phenomenon of shear dilatancy in the shearing process, and its dilatancy will be more obvious with the increased proportion of rock or the decreased confining pressure. The proportion of rock has great effect on the strength of S-RM and rock-block, especially the spatial position of particles with comparatively big size has great effect on the shape and spatial position of the sample shear zone. The dissertation makes some improvements in the single ring infiltration test equipment and its application on the permeability of S-RM. The results indicate that the increasing of rock-block would make it more difficult for the soil to fill in the vacuity between the rock-block and the proportion would increase which would result in the increased permeability coefficient. The dissertation builds the real meso-structural model of S-RM based on the digital image processing technology. By using geometric reconstruction technology, it transfers the structural mode represented by Binary image into CAD format, which makes it possible to introduce the present finite element analysis software to take research on numerical experimental investigation. It systematically realizes leaping research from the image，geometric mode, to meso-structural mechanics numerical experiment. By using this method, the dissertation takes large scale numerical direct-shear test on the section of S-RM. From the mesoscopic perspective, it reveals three extended modes about the shear failure plane of S-RM. Based on the real meso-structural model and by using the numerical simulation test, the character and mechanics of seepage failure of S-RM are studied. At the same time, it builds the real structural mode of the slope based on the analysis about the slope crosssection of S-RM. By using the strength reduction method, it takes the research on the stability of S-RM and gets great achievements. The three dimensional geometric reconstruction technology of rock block is proposed, which provides technical support for the reconstruction of the 3D meso-structural model of S-RM. For the first time, the dissertation builds the stochastic structure model of two-dimensional and three-dimensional polygons or polyhedron based on the stochastic simulation technique of monte carlo method. It breaks the traditional research which restricted to the random generation method of regular polygon and develops the relevant software system (R-SRM2D/3D) which has great effect on meso-structural mechanics of S-RM. Based on the R-SRM software system which randomly generates the meso-structural mode of S-RM according to the different meso-structural characteristics, the dissertation takes a series of research on numerical test of dual axis and real three-axis, systematically analyses the meso destroy system, the effects of meso-structural characteristics such as on the stone content, size composition and block directionality on the macro mechanical behavior and macro-permeability. Then it proposes the expression of the upper and lower limit for the macro-permeability coefficient of the inhomogeneous geomaterials, such as S-RM. By using the strength reduction FEM, the dissertation takes the research on the stability of the slope structural mode of the randomly formed S-RM. The results indicate that generally, the stability coefficient of S-RM slope increases with the increasing of stone content; on the condition of the same stone content, the stability coefficient of slope will be different with different size composition and the space position of large block at the internal slop has great effect on the stability. It suggests that meso-structural characteristics, especially the space position of large block should be considered when analyzing the stability of this kind of slope and strengthening design. Taking Xiazanri S-RM slope as an example, the dissertation proposes the fine modeling of complicated geologic body based on reverse engineering and the generation method of FLAC3D mode. It resolves the bottleneck problem about building the fine structural mode of three-dimensional geological body. By using FLAC3D, the dissertation takes research on the seepage field and the displacement field of Xiazanri S-RM slope in the process of reservoir water level rising and decreasing. By using strength reduction method, it analyses the three-dimension stability in the process of reservoir water level rising and decreasing. The results indicate that the slope stability firstly show downward trend in the process of reservoir water level rising and then rebound to increase; the sudden drawdown of reservoir water level has great effect on the slope stability and this effect will increase with the sudden drawdown amplitude rising. Based on the result of the rock block size analysis of S-RM, and using R-SRM2D the stochastic structure model of Xiazanri S-RM slope is built. By using strength reduction method, the stability of the stochastic structure model is analysis, the results shows that the stability factor increases significantly after considering the block.

水库滑坡复活机理及其发展趋势预测研究

Various numbers of ancient landslides of various scales are frequently distributed on both banks of reservoirs, especially large reservoirs, both in China and abroad. During inundation and operation of theses reservoirs, some of the landslides are reactivated, which caused losses of people's lives and properties to various extents, some even disasters. Systematic studies are, however, very few on the reservoir-induced reactivation mechanism and development tendency prediction. Based on investigation of reservoir-induced reactivation phenomena of ancient landslides and relevant existing research problems, a systematic study is carried out on the field identification, induced reactivation mechanism, development tendency prediction, risk decision-making and treatment of reservoir-related ancient landslides, through analysis of large numbers of engineering geological investigation results, scientific experimental and research results, in combination with prevention and treatment practices of reservoir-related landslides both in China and abroad, and a series of research results have been obtained. 1. On the basis of study of the distribution features, genesis mechanism of ancient landslides on river banks, a set of scientific methods are summarized on field identification of ancient landslides, and a significant method named "lithologic sequence method" or "indicator layer method", is proposed, which is proved to be very useful. 2. A detail study is made on the reservoir-induced hydraulic effects and material mechanic effects (or softening effects) on the ancient landslide through model and case studies, which concludes that the magnitude and properties of reservoir-induced hydraulic effects are related to the shapes of sliding planes, water content and permeability of landslide materials and variation rate and magnitude of reservoir levels; the magnitude of material mechanic effects are related to the material composition (including mineral composition and grain size), natural water content and saturation state of sliding zones. Also a sensitive analysis is made on the factors that are related to the stabilities of the landslides, which indicate that the stability of a landslide is more sensitive to the groundwater head h_w in the slides and the inner friction angleψof sliding zones than others. 3. The joint inducing mechanism of rainfall and reservoir is also discussed in the paper through model analysis and case study, which proves that reservoir inundation increases firstly the sensitivity of a landslides to rainfall through reduction of its stability or cracking deformation which will increase the rainfall infiltration to the slide body, and then rainfall triggers reactivation or intensifies the reservoir-induced deformation of a landslide. 4. Based on rheologic test results of sliding zones of several reservoir-related ancient landslides, the rheologic characteristics of sliding zones have been discussed in detail and several typical rheologic models have been set up, which well explains the dynamic process of slide deformation. The response types to reservoir inundation and development tendency of reservoir -related ancient landslide are discussed in the paper based on field investigation results. And prediction methods for reservoir-related landslides have been studied based on the Mate-Synthetic principle of quantitative and qualitative analysis, as well as combination of computation and internal mechanism analysis, and a rheologic analytical method is proposed which is proved very useful for prediction of the landslide development tendency. 6. In disaster-prevention and treatment of reservoir-related landslides, risk decision-making has been proved very significant both in engineering and economics. Based on the practices in disaster-prevention and treatment of reservoir-related landslides both in China and abroad, the disaster-prevention risk decision-making for reservoir-related landslides has been proposed in terms of philosophy, methods and procedures, and well put into practice. A summary is also made through case study of the experiences of treatment of reservoir-related landslides both in China and abroad in terms of principle, methods and technical lines. 7 A detail study is made as a case study of the reactivated Maoping ancient landslide on the left bank of the Geheyan Reservoir on Qingjiang river in Hubei province, China, including its field identification features, reservoir-induced reactivation characteristics and mechanism, development tendency prediction and proposed counter measures based on risk analysis.

环渤海地区地壳和上地幔地震层析成像研究

In Circum-Bohai region (112°~124°E, 34°~42°N ), there exists rich gas-petroleum while inner-plate seismic activity is robust. Although the tectonic structure of this region is very complicated, plenty of geological, geophysical and geochemical researches have been carried out.In this paper, guided by the ideas of "One, Two, Three and Many" and "The depth controls the shallow, the regional constrains the local", I fully take advantage of previous results so as to establish a general image of this region. After collecting the arrival-time of P-wave phases of local events and tele-seismic events recorded by the stations within this region from 1966 to 2004, I process all these data and build an initial model. Then, a tomography image of crust and upper-mantle of this region is obtained. With reference to previous results, we compare the image of various depths and five cross-profiles traverse this region along different direction. And finally, a discussion and conclusion is made.The principle contents is listed as below: 1) in the first chapter, the purpose and meaning of this thesis, the advance in seismic tomography, and the research contents and blue-print is stated; 2) in the second chapter, I introduce the regional geological setting of Circum-Bohai region, describe the tectonic and evolutionary characteristics of principle tectonic units, including Bohai Bay Basin, Yanshan Fold Zone, Taihangshan Uplifted Zone, Jiao-Niao Uplifted Zone and Luxi Uplifted Zone, and primary deep faults; 3) In the third chapter, the previous geophysical researches, i.e., gravity and geomagnetic characters, geothermal flow, seismic activity, physical character of rocks, deep seismic sounding, and previous seismic tomography, are discussed; 4) in the fourth chapter, the fundamental theory and approach of seismic tomography is introduced; 5) in the fifth chapter, the technology and approaches used in this thesis, including collecting and pre-processing of data, the establishment of initial velocity model and relocation of all events; 6) in the sixth chapter, I discuss and analyze the tomography image of various depth and five cross-sections; 7)in the seventh chapter, I make a conclusion of the results, state the existing problems and possible solutions.

内在参照轴在图形再认中的作用

Shape recognition is among the basic skills to live in the complex environment. There are already a series of studies found interesting mental phenomena in shape recognition, such as mental rotation, which was also found in scene recognition and suggested that there would be common mechanisms in these two recognition processes. Recently, Mou and his colleagues (2008) found that scene recognition was not only viewpoint dependent but also intrinsic-orientation dependent. In our study, we applied their part recognition paradigm to shape recognition and investigated whether there was intrinsic orientation effect in shape recognition, and furthermore, we investigated the selection of the intrinsic axis in shape recognition. The results showed that a test shape divided from the learning direction and thus containing intrinsic axis was easier to recognize, relative to the test shape which was not divided from the learning direction. The results also showed that a test shape presented from the viewing direction was easier to recognize than from other direction. Furthermore, after we added an oblique rectangular background to the learning shape, the results showed that participants chose the prolate axis of the rectangular background as their learning direction and thus the direction of the intrinsic axis. This result suggested that the direction of the intrinsic axis can be separated from the viewing direction, and background can play a decisive role in the selection of intrinsic axis.

序列学习场景条件下学习序列与空间记忆内在参照系的建立

Previous studies showed that preferred directions in pointing judgments (e.g. imagine you are standing at X, facing Y, please point to Z) were consistent with the sequence participants used to learn locations of objects suggesting that the learning sequence may determine the intrinsic frames of reference in spatial memory. Numerous studies pay excessive attention to the selection of intrinsic frames of reference in spatial memory acquired from viewing an entire layout simultaneously. This research focused on the relationship between the learning sequence and the spatial reference direction in sequentially learning a layout based on the theory of intrinsic reference system. The results indicated that: 1. The intrinsic frame of reference used to specify objects’ locations in memory could not be determined by learning sequence. The learning sequence reflected the encoding of interobject spatial relations aligned with the intrinsic reference directions . 2. when the objects presented sequentially in a random order and the layout geometry structure was either all along or briefly, the preferred heading was determined by the symmetric axis. when the objects presented sequentially in a random order and the layout geometry structure was either not indicated or briefly presented after study, the preferred heading was determined by learning viewpoint. 3. When the objects were presented sequentially along a certain direction, whether the layout geometry structure displayed or not, the effect of the learning viewpoint on selection of intrinsic axis was observed. 4. When participants learned a layout during locomotion, whether the layout geometry structure displayed or not, the initial study perspective was used as a reference direction in memory. 5. Spatial reference direction was determined at the very beginning of learning objects’ locations. Spatial reference direction could not be changed once it had been choosed. These results not only contribute to specify in greater detail the nature of these spatial representations but also extend the intrinsic model of spatial memory.

物体朝向对场景内在参照系建立的影响

Six experiments tested how headings of objects in scenes influenced the construction for the intrinsic frame of reference under different structure and viewpoint amount conditions. In Experiment 1 and 2, participants stood at 0 degree and learned an asymmetrical scene and a symmetrical scene that were composed by balls with no apparent headings separately. In Experiment 3, 4, 5 and 6, toys with apparent headings were used and they all faced the 315 degree of the scene. In Experiment 3 and 4, participants stood at 0 degree and learned an asymmetrical scene and a symmetrical scene that were composed by toys separately. In Experiment 5 and 6, participants stood at 0 and 315 degree and learned an asymmetrical scene and a symmetrical scene that were composed by toys separately. After learning, participants needed to finish triplet recognition tasks in all the experiments. The dependent measures were response latency and accuracy. The correct response latencies to the targets were analyzed by ANOVA. Accuracy was used to filter data and analyzed in an ANOVA in some experiments as a reference. Results indicate that headings of objects in scenes influence the pattern for intrinsic frame of reference. The structure of scene affects the acting mechanism of heading, but the amount of viewpoints does not have this effect. If the objects in scenes have no apparent headings, there will be viewpoint dependent effect and the advantage of symmetry axis as intrinsic axis in triplet recognition tasks. If the objects in scenes have apparent headings, people’s spatial memory pattern will be affected by objects’ headings. If the heading of objects (315 degree) is not parallel to the viewpoint (0 degree) in an asymmetrical scene, people will be inclined to represent the scene from the heading of objects but not from the viewpoint. As a result, the viewpoint dependent effect will disappear, and there is significant advantage for the triplets presented from heading of objects. If the heading of objects is not parallel to the symmetry axis in a symmetrical scene, people will represent the scene not only according to the symmetry axis as intrinsic axis, but also according to the heading of objects. As a result, the significant advantage for symmetry axis as intrinsic axis in triplet recognition tasks will disappear but there will be still a tendency. By contrast, the effect for the headings of objects is more significant in asymmetrical scenes than that in symmetrical scenes.

Curved Inertia Frames: Visual Attention and Perceptual Organization Using Convexity and Symmetry

In this paper we present an approach to perceptual organization and attention based on Curved Inertia Frames (C.I.F.), a novel definition of "curved axis of inertia'' tolerant to noisy and spurious data. The definition is useful because it can find frames that correspond to large, smooth, convex, symmetric and central parts. It is novel because it is global and can detect curved axes. We discuss briefly the relation to human perception, the recognition of non-rigid objects, shape description, and extensions to finding "features", inside/outside relations, and long- smooth ridges in arbitrary surfaces.