A three-dimensional semi-implicit unstructured grid finite volume ocean model

A new three-dimensional semi-implicit finite-volume ocean model has been developed for simulating the coastal ocean circulation, which is based on the staggered C-unstructured non-orthogonal grid in the hor- izontal direction and z-level grid in the vertical direction. The three-dimensional model is discretized by the semi-implicit finite-volume method, in that the free-surface and the vertical diffusion are semi-implicit, thereby removing stability limitations associated with the surface gravity wave and vertical diffusion terms. The remaining terms in the momentum equations are discretized explicitly by an integral method. The partial cell method is used for resolving topography, which enables the model to better represent irregular topography. The model has been tested against analytical cases for wind and tidal oscillation circulation, and is applied to simulating the tidal flow in the Bohal Sea. The results are in good agreement both with the analytical solutions and measurement results.

Numerical Simulation of the Three-Dimensional Wave-Induced Currents on Unstructured Grid

By coupling the three-dimensional hydrodynamic model with the wave model, numerical simulations of the three- dimensional wave-induced current are carried out in this study. The wave model is based on the numerical solution of the modified wave action equation and eikonal equation, which can describe the wave refraction and diffraction. The hydrodynamic model is driven by the wave-induced radiation stresses and affected by the wave turbulence. The numerical implementation of the module has used the finite-volume schemes on unstructured grid, which provides great flexibility for modeling the waves and currents in the complex actual nearshore, and ensures the conservation of energy propagation. The applicability of the proposed model is evaluated in calculating the cases of wave set-up, longshore currents, undertow on a sloping beach, rip currents and meandering longshore currents on a tri-cuspate beach. The results indicate that it is necessary to introduce the depth-dependent radiation stresses into the numerical simulation of wave-induced currents, and comparisons show that the present model makes better prediction on the wave procedure as well as both horizontal and vertical structures in the wave-induced current field.

Grid-based computer-generated holograms synthesizing for holographic three-dimensional display

To reduce the computing time of composite computer-generated holograms （CGHs） gen- eration based upon the angular projection algorithm for holographic three-dimensional （3D） display, a grid-based holographic display （ GHD ） scheme was designed. The grid computing technology was applied to numerically process the different angular projections of an object in distributed-parallel manner to create the corresponding CGHs. The whole treatment of a projection was regarded as a job executed on the grid node machine. The number of jobs which were submitted to grid nodes, therefore, was equal to that of the projections of the object. A Condor-based grid testbed was constructed to verify the feasibility of the GHD scheme, and a graphical user interface （GUI） program and several service modules were developed for it. A 3D terrain model as an example was processed on the testbed. The result showed that the scheme was feasible and able to improve the execution elficiency greatly.

Three-dimensional tidal current numerical model of the Oujiang Estuary

The characteristics of three-dimensional （3-D） tidal current in the Oujiang Estuary are investigated according to in situ observations. The Oujiang Estuary has features of irregular coastline, complex topography, many islands, moveable boundary, and submerged dyke, therefore, σ 3-D numerical model oil an unstructured triangular grid has been degeloped. The σ coordinate transforination, the moveable boundary and submerged dyke treatment techniques were employed in the model so it is suitable for the tidal simulations in the Oujing Estuary with submerged dyke and moveable boundary problems. The model is evaluated with the in situ data, and the results show that the calculated water elevations at 19 stations and currents at 19 profiler stations are in good agreement with measured data both in magnitude and phase. This numerical model is applied to the 3-D tidal circulation simulations of experiments in stopping flow transport through the South Branch of the Oujiang Estuary, and the feasibility to cutoff the flow in the South Branch of the Oujiang Estuary is demonstrated by numerical simulation experiments. The developed numerical model simulated the 3-D tidal current circulations in complicated coastal and estuarine waters very well.

Geologic body three-dimensional model generation and visualization method

The divergence three-dimensional millet-seed body model and the continuous distributing layer-imitating model were introduced, which were used to express geologic body, and the procedure of generating these two models and their merits and demerits were synthesized. Three methods of geologic body’s three-dimensional expression were separately introduced, and the merits of the continuous distributing layer imitating model were proposed as comparing with the divergence three-dimensional millet-seed body model. The three-dimensional cubes were observed from any direction and any tangle with the application of dealing methods such as peeling, hollowing out, transparent or half-transparent.

Boundary effect of toppling failure based on three-dimensional mechanical model

Previous researches on the mechanical model of toppling failure mainly concentrated on twodimensional mechanical model(TwDM) analysis. The TwDM analysis assumes the width of the slab beam is unit width without considering the lateral constraint force. The assumed conditions are obviously different from the site conditions, thus there is a certain difference between the calculated results and the field work. A three-dimensional mechanical model(ThDM)of toppling failure was established, considering that the slab beam was mainly subject to self-weight, the frictional resistance of interlayer and lateral constraint force. Due to the progressive characteristics of toppling failure, the concept and the formula of the first fracture depth(FFD) of toppling was raised and constructed. The case study indicates that the ThDM is more effective and can be accurately used to calculate the toppling fracture depth of the slab beam. The FFD decreases proportionally with the increase of slab beam width. FFD grows fast when the slab beam width is less than 2.0 m and it tends to be stable when the slab beam width is above 2.0 m. The FFD decreases with the increase of the lateral constraint coefficient, indicating that the boundary condition of the free space is positively correlated with the stability and depth of toppling. This is a good explanation of the free space effect. This study provides a reference for the stability evaluation and prevention-control design of toppling slope in the future.

Three-dimensional anthropometry in periorbital region

Anthropometry can analyze the size,weight,and proportion of the human body objectively and quantitatively to supplement the visual assessment.Various non-invasive three-dimensional(3D)anthropometric techniques have been applied to assess soft tissues’3D morphology in the clinical practice.Among them,non-invasive stereophotogrammetry and laser scanning techniques are becoming increasingly popular in craniofacial surgery and plastic surgery.They have been applied for craniofacial growth estimation and morphometric investigation,genetic and acquired malformation diagnosis,as well as orthodontic or surgical treatment arrangement and outcome evaluation.However,few studies have been published for assessing the 3D morphology of soft tissues in the periorbital region.This paper reviews the studies involving the application and evaluation of the increasingly popular 3D photogrammetry in the periorbital region.These studies proposed detailed and standardized protocols for three-dimensionally assessing linear,curvilinear,angular,as well as volumetric measurements,and verified its high reliability in the periorbital region(even higher than caliper-derived direct measurements).In the future,reliable and accurate 3D imaging techniques,as well as standardized analyzing protocols,may find applications in following up morphological growth,preoperatively diagnosing and assessing patient periorbital conditions,planning surgical procedures,postoperatively evaluating treatment outcomes of a specific procedure,and comparing the differences in surgical results between various procedures,studies,as well as populations.

Design Theory of Full Face Rock Tunnel Boring Machine Transition Cutter Edge Angle and Its Application

At present, the inner cutters of a full face rock tunnel boring machine (TBM) and transition cutter edge angles are designed on the basis of indentation test or linear grooving test. The inner and outer edge angles of disc cutters are characterized as symmetric to each other with respect to the cutter edge plane. This design has some practical defects, such as severe eccentric wear and tipping, etc. In this paper, the current design theory of disc cutter edge angle is analyzed, and the characteristics of the rock-breaking movement of disc cutters are studied. The researching results show that the rotational motion of disc cutters with the cutterhead gives rise to the difference between the interactions of inner rock and outer rock with the contact area of disc cutters, with shearing and extrusion on the inner rock and attrition on the outer rock. The wear of disc cutters at the contact area is unbalanced, among which the wear in the largest normal stress area is most apparent. Therefore, a three-dimensional model theory of rock breaking and an edge angle design theory of transition disc cutter are proposed to overcome the flaws of the currently used TBM cutter heads, such as short life span, camber wearing, tipping. And a corresponding equation is established. With reference to a specific construction case, the edge angle of the transition disc cutter has been designed based on the theory. The application of TBM in some practical project proves that the theory has obvious advantages in enhancing disc cutter life, decreasing replacement frequency, and making economic benefits. The proposed research provides a theoretical basis for the design of TBM three-dimensional disc cutters whose rock-breaking operation time can be effectively increased.

The three-dimension model for the rock-breaking mechanism of disc cutter andanalysis of rock-breaking forces

To study the rock deformation with three- dimensional model under rolling forces of disc cutter, by car- rying out the circular-grooving test with disc cutter rolling around on the rock, the rock mechanical behavior under rolling disc cutter is studied, the mechanical model of disc cutter rolling around the groove is established, and the the- ory of single-point and double-angle variables is proposed. Based on this theory, the physics equations and geometric equations of rock mechanical behavior under disc cutters of tunnel boring machine （TBM） are studied, and then the bal- ance equations of interactive forces between disc cutter and rock are established. Accordingly, formulas about normal force, rolling force and side force of a disc cutter are de- rived, and their validity is studied by tests. Therefore, a new method and theory is proposed to study rock- breaking mech- anism of disc cutters.

以人为范 寓道于器:唐宋建筑与造像一体化设计模式初探

围绕古代建筑与造像间尺度设计关联性的问题,分析了建筑和造像两种体系存在的难题及应对策略,梳理了统摄性方法的产生逻辑和全局基准长的探寻思路,提出建筑与造像一体化设计方法。通常是以具有文化意义且符合整尺的事物(如塑像面部)作为基准长,以屋心或像心为定位依据,运用方格网、同心圆、放射线,通过几何作图而实现。结合唐宋时期实例验证了操作手法并剖析其设计本质,阐释了一体化设计模式中所蕴含的“数形义合一”营造理念、“天圆地方、建极向心”宇宙观、人本理念、型范思维。研究进一步揭示了古代营造智慧及其演化脉络,也为探寻共同基准长、复原营造尺、发现设计模式的跨时空关联等提供新思路。

A MULTIGRID-ACCELERATED THREE-DIMENSIONAL TRANSIENT-FLOW CODE AND ITS APPLICATION TO A NEW TEST PROBLEM

A multigrid-assisted solver tbr the three-dimensional time-dependent incompressible Navier-Stokes equations on graded Cartesian meshes is developed. The spatial accuracy is third-order for the convective terms and fourth-order for the viscous terms, and a fractional-step strategy ensures second-order time accuracy. To achieve good time-wise efficiency a multigrid technique is used to solve the highly time-consuming pressure-Poisson equation that requires to be solved at every time step. The speed-up achieved by multigrid is shown in tabular form. The performance and accuracy of the code are first ascertained by computing the flow in a single-sided lid-driven cubic cavity with good grid-economy and comparing the results available in the literature. The code, thus validated, is then applied to a new test problem we propose and various transient and asymptotically obtained steady-state results are presented. Given the care taken to establish the credibility of the code and the good spatio-temporal accuracy of the discretization, these results are accurate and may be used for ascertaining the performance of any computational algorithm applied to this test problem.

基于图像和人工鱼群算法的建筑火灾动态疏散路径规划研究

为了解决大型建筑发生火灾时传统静态疏散系统无法根据火灾点和人员拥挤程度进行路径调整这一问题,提出了基于图像和人工鱼群算法的动态疏散路径规划方法。在栅格图上进行路径规划,通过将鱼群的最优解替换为可行解,使鱼群避免陷入局部最优和全局最优相互干扰的情况,并结合摄像头采集图像,通过人脸识别人数,判断当前路径是否拥挤,及时调整路径,从而确保规划出的路径可以避免堵塞,动态疏散人群。仿真实验结果表明,所提算法能够在相同时间内,规划出较蚁群算法路径更短,可避免陷入局部最优和死锁状态,根据拥挤程度及时改变路径,并能够在时间和空间双重约束的情况下实现人群动态疏散。因此,新算法在相同运行时间内可以规划出更短的路径,可以帮助火灾现场人群以更少时间、更短路径、更高效率的方式进行动态疏散。

竖式风扇面板注射模设计

针对竖式风扇面板因形状细长而导致注射成型变形的问题,使用热流道转普通流道的方式进浇;为了避免型腔填充不足现象,成型塑件横格栅和深度较深的筋位采用镶件;为方便成型零件加工,动模型芯采用镶拼结构;为简化斜推机构,斜推座采用滑板和旋转轴结构,并在分型面上设置合模间隙和排气槽排出型腔内气体。经实际生产验证,模具运行平衡,成型的塑件质量好,为类似塑件模具设计提供了参考。

基于人脸识别技术的10 kV配电站远程许可系统应用

提出了基于人脸识别技术的10 kV配电站远程许可系统,该系统由许可终端装置、身份认证装置、人脸识别摄像机、智能自动锁组成,通过应用信息网络和人脸识别技术将许可工作与现场工作人员关联,由运维人员在集控站远程核实任务正确后打开配电站门禁,并通过人脸识别摄像机进行远程管控,实现了运维人员无需到现场开门许可第二种工作票且能实时进行现场管控,提高了工作效率和电网数字化水平。

综采工作面采空区漏风规律数值模拟

为得到综采工作面及其采空区的流场分布,基于通风网络理论推算得出采空区漏风阻力系数模型。该模型综合考虑采面的回采速度,顶板岩性,采空区倾向上顶板的沉降量等因素影响,利用FLUENT软件及其自适应网格技术,对国投新集能源股份有限公司刘庄煤矿121103工作面及其采空区漏风流场进行数值模拟,并对模拟结果与现场实测工作面风量分布进行比较,工作面风量分布趋势吻合较好。模拟结果表明：该工作面向采空区漏风主要发生在倾向0~25 m区域内,在该区域内,漏入采空区内的风量有部分返回至工作面;在倾向25~215 m区域内,工作面风量变化不大;采空区漏风流场等值线在倾向上并不是对称分布的,在采空区走向0~10 m及倾向20~30 m区域内存在低速区。

基于网格搜索算法的PCNN模型参数自适应

为提高利用脉冲耦合神经网络(pulse coupled neural network,PCNN)模型进行人脸识别时的准确率,并解决利用PCNN进行人脸识别时,模型中多个参数需凭经验设定的问题,提出一种基于脉冲发放强度的PCNN(QD-PCNN)模型和改进的网格搜索算法。QD-PCNN模型在简化的PCNN模型基础上,引入脉冲发放强度,细化模型的输出。改进的网格搜索算法在进行参数寻优时,根据识别对象,在较大范围内搜索,在得到的寻优结果附近区域进行精确搜索。在实验中,将通过改进的网格搜索法得到的参数组合运用到QD-PCNN模型中进行人脸识别,实验结果验证了该方法的有效性。

基于网格光的三维人脸曲面测量

本文提出了一种借助网格光从两张二维图片中测量三维人脸曲面的方法。为了保护皮肤和眼睛并且降低成本,本文中使用的网格光来自普通的白光光源。首先,一个简单的并且未编码的网格图案被投影到目标人脸上;然后,一个基于边缘信息的分水岭算法被用于提取和细化网格条纹,一个基于图形联系关系的方法被用于定位与标记网格的交叉点,利用这个网格交叉点的标记集一个迭代扩张的立体匹配算法可以执行交叉点的立体对应;最终,依据双目视觉的原理计算人脸的三维深度信息。所得的实验结果展示了我们提出的方法的可行性。

基于网格的自适应弹性图人脸匹配方法

采用基于脸部结构的区域分割方法将人脸分成多个子区域;用不同密集度的弹性图划分和不同的变形粒度实现弹性变形,采用确定性退火算法找到弹性变形的最佳匹配;在网格平台上通过基于时间约束的最小花费调度策略并行实现文中方法.在较大的人脸库规模和非约束环境下,该方法在识别速度和识别率上有所提高.

三维非结构化网格表面物性数据的快速可视化方法

根据三维非结构化网格数据的固有特点，提出了两种将其单元面按外部面和内部面分类的算法；在比较两种算法的基础上，选择基于最小（或最大）节点编号相关面的外部面集生成算法，利用Ｚ缓存器算法实现了对数据场表面分布图的一种快速显示，与基于一般多面体隐藏面消除的表面分布图显示算法比较，具有高效、快速、易于实现等特点。

采用自适应直角网格计算三维增升装置绕流

针对三维增升装置绕流，对存在剪刀叉的不连续外形，基于自适应直角网格，提出并介绍了分区和面搭接技术，采用变长宽比网格，进行了直角网格生成和流场 Euler 方程数值计算．根据几何外形的特点，在直角网格生成过程中，以外形不连续面作为分区边界，对初始“根”网格实施分区处理，降低了整个网格的生成难度．通过基于外形的自适应网格加密，详细描述了剪刀叉外形和缝道，提高了网格质量．在分区边界面上，基于面搭接技术，构造重叠面积切割算法，实现边界两侧网格间的流场信息传递，保证流场计算中的通量守恒．采用中心有限体积方法，结合双时间推进算法，完成了两段机翼、带增升襟翼翼身组合体绕流流场的 Euler 方程数值模拟，对计算结果与实验数据进行了对比，验证了所提方法、算法的合理性和实用性．