三维建筑模型论文中英文资料对照外文翻译文献
三维建筑模型
中英文资料
Constructing Rules and Scheduling Technology for 3D
Building Models
Zhengwei SUI, Lun WU, Jingnong WENG, Xing LIN, Xiaolu JI
Abstract
3D models have become important form of geographic data beyond conventional 2D geospatial data. Buildings are important marks for human to identify their environments, because they are close with human life, particularly in the urban areas. Geographic information can be expressed in a more intuitive and effective manner with architectural models being modeled and visualized in a virtual 3D environment. Architectural model data features with huge data volume, high complexity,
non-uniform rules and so on. Hence, the cost of constructing large-scale scenes is high. Meanwhile, computers are lack of processing capacity upon a large number of model data. Therefore, resolving the conflicts between limited processing capacity of computer and massive data of model is valuable. By investigating the characteristics of buildings and the regular changes of viewpoint in virtual 3D environment, this article introduces several constructing rules and scheduling techniques for 3D constructing of buildings, aiming at the reduction of data volume and complexity of model and thus improving computers’ efficiency at schedul ing large amount of architectural models. In order to evaluate the efficiency of proposed constructing rules and scheduling technology listed in the above text, the authors carry out a case study by 3D constructing the campus of Peking University using the proposed method and the traditional method. The two results are then examined and compared from aspects of model data volume, model factuality, speed of model loading, average responding time during visualization, compatibility and reusability in 3D geo-visualization platforms: China Star, one China’s own platform for 3D global GIS manufactured by the authors of this paper. The result of comparison reveals that models built by the proposed methods are much better than those built using traditional methods. For the constructing of building objects in large-scale scenes, the proposed methods can not only reduce the complexity and amount of model data remarkably, but can also improving computers’ efficiency.
Keywords:Constructing rules, Model scheduling, 3D buildings
I. INTRODUCTION
In recent years, with the development of 3D GIS (Geographical Information System) software like Google Earth, Skyline, NASA World Wind, large-scale 3D building models with regional characteristics have become important form of geographic data beyond conventional 2D geospatial data, like multi-resolution remote sensing images and vector data [1].Compared to traditional 2D representation, geographic information can be expressed in a more intuitive and effective manner with architectural models being modeled and visualized in a virtual 3D environment. 3D representation and visualization provides better visual effect and vivid urban geographic information, and thus plays an important role in people's perceptions of their environment. Meanwhile, the 3D building data is also of great significance for the construction of digital cities.
But how to efficiently visualize thousands of 3D building models in a virtual 3D environment is not a trivial question. The most difficult part of the question is the conflicts between limited processing capacity of computer and massive volume of model data, particularly in the procedure of model rendering. Taking the 3D modeling
of a city for the example using traditional 3D modeling method, suppose there are 100 000 buildings to model in the urban area and the average size of model data for each building is roughly 10 M. So the total data volume of building models in the city could reach a TB level. However, the capacity of ordinary computer memory is only in the GB scale. Based on this concern, the authors proposed the scheduling technology for large-scale 3D buildings models in aspects of model loading and rendering. Due to the lack of building constructing rules and standard, models of buildings vary in aspects of constructing methods, textures collection and model data volume, especially in aspects of model reusability and factuality. Such a large amount of data without uniform constructing rules becomes a huge challenge for data storage, processing and visualization in computers. It also brings the problem of incompatibility among different 3D GIS systems.
After years of research in GIS (Geographic Information System), people have accumulated a number of ways to solve the above problems [3]. However in virtual 3D environment, because of the difference in data organization and manners of human computer interaction (HCI), we need to apply a new standardized method of modeling and scheduling for 3D models. At present, there is no such a uniform method as the constructing specification or standard for the modeling of 3D buildings. Existing approaches are insufficient and inefficient in the scheduling of large-scale building models, resulting in poor performance or large memory occupancy. In response to such questions, the authors proposed a new method for the construction of 3D building models. Models built using the proposed methods could be much better than those built using traditional methods. For the 3D modeling of building objects in scenes of large scale, the proposed methods can not only remarkably reduce the complexity and amount of model data, but can also improving the reusability and factuality of models. Concerning the scheduling of large-scale building models, the Model Loading Judgment Algorithm (MLJA) proposed in this paper could solve the optimal judgment problem of model loading in 3D vision cone, particularly in circumstance with uncertain user interactions.
This paper first examines and analyzes existing problems in constructing and
scheduling steps of 3D building models. Then the authors propose a set of constructing rules for 3D building models together with methods of model optimization. Besides, special scheduling technology and optimization method for model rendering is also applied in this paper for large-scale 3D building models. In order to evaluate the efficiency of proposed rules and methods, a case study is undertaken by constructing a 3D model for the main campus of Peking University and Shenzhen using both the proposed method and the traditional method respectively. The two resulting 3D models of Peking University campus and Shenzhen are then examined and compared with one other in aspects of model data volume, model factuality, speed of model loading, average responding time during visualization, compatibility and reusability in various 3D geo-visualization platforms like China Star (one China’s own platform for 3D global GIS manufactured by the authors), Skyline, etc. Result of comparison tells that provided similar factuality of models, using the proposed method of us, the data volume of models was reduced by 86%; the speed of model loading was increased by 70%; the average responding time of model during visualization and interaction speed was reduced by 83%. Meanwhile, the compatibility and reusability of 3D model data are also improved if they are constructed using our approach.
II. MODELING RULES OF 3D BUILDINGS 3D scene is the best form of visualization for digital city systems. While constructing 3D models for buildings objects, proper methods and rules should be used, which are made with full concerns of the characteristics of 3D building models [2]. The resulting models should be robust, reusable and suitable enough for transmission over computer network, and should at the same time be automatically adapted to system capability.
Generally speaking, methods of constructing 3D building models can be classified into three types: wireframe modeling, surface modeling and solid modeling. In normal circumstances, to model buildings in 3D format, the framework of building should be constructed first according to the contour features, number of floors, floor
height, aerial photograph and liveaction photos of buildings. Then, gather the characteristics of scene that the buildings to model are representing. Important characteristics include buildings aerial photograph or liveaction shooting photos. Finally, map the gathered texture to model framework, optimize the model and create database of the 3D building models.
Although there have already been many approaches for the construction of 3D building models, a unified modeling method and rules are still needed to improve the efficiency, quality, facilitate checking, reusability and archiving of constructed models. By investigating the characteristics of buildings, we found that buildings have regular geometric solid for modeling, similar texture on the surfaces of different directions, high similarity in small-scale models of buildings, etc. According to these, this article gives a discussion on the modeling rules from three aspects, including constructing rules of the 3D building models, texture mapping rules of 3D building models and optimization method for constructed models based on mentioned constructing rules.
A. Constructing rules of the 3D building models
The 3D building modeling refers to the procedure of representing true buildings from the real world into computer in the form of 3D objects [4]. Human beings, as the creator and at the same time potential users of models, play a key role in this procedure. People are different from each other in the understanding of the building objects, methods of modeling and the software tools they use for modeling. Such differences among people who carry out modeling work at the same time lead to the 3D models of diverse quality and low efficiency. So the 3D building constructing rules proposed in this article become necessary and helpful to solve the above problems.
1) Combine similar floors as a whole and keep the roof independent
2) Share similar models and process the details especially
3) Constructing in the unit of meters
4) Define central point of the model
5) Unified model codes
6) Reduce number of surfaces in a single model
7) Reduce combination of the models
8) Rational split of models
B. Texture mapping rules of 3D buildings
Based on the framework of 3D models, we need to attach these models with proper textures to create a better visualization effect for 3D buildings. The quality of texture mapping has a direct impact on the visual effect of the scene whiling being rendered [5]. Since the graphics card of computer will load all the textures together when rendering a model, texture mapping rules and the quality of the texture mapping can directly influence the efficiency of rendering as well.
C. Optimization of models based on constructing rules
Based on constructing rules and the characteristics of 3D building models, the authors develop a software tool to optimize the 3D building models automatically. The optimizations impl emented in the software tool contain the deletion of models’ internal textures, merging adjacent vertices/lines/surfaces, removing un-mapped framework and so on. Besides, the software can enhance the shape of the whole model, texture position and model facticity in the procedure of model optimization.
III. SCHEDULING TECHNOLOGY OF LARGE-SCALE 3D
BUILDING MODELS
For the 3D visualization of large-scale architectural models, a series of measures could be applied to ensure the efficient rendering of models. Important measures includes the scene organization, vision cone cutting, elimination of textures on the backside of models, Shader optimization, LOD Algorithm, math library optimization, memory allocation optimization, etc..
How to display thousands of 3D cit y buildings’ models in a virtual 3D environment is not trivial. The main problem is the scheduling of models [7]. It determines when and which models to be loaded. This problem can be divided into two smaller problems: Find visible spatial region of models in 3D environment, and optimization method of model rendering efficiency.
A. Find visible spatial region of models in 3D environment
According to operating mechanism of computers during 3D visualization and the characteristics of large-scale 3D scene, we need to determine the position of current viewpoint first before loading signal models or urban-unit models. Then in response to the regular changes of viewpoint in virtual 3D environment, the system will preload the 3D model data into memory automatically. In this way, frequent IO operations can be reduced and thus overall efficiency of system gets improved. A new algorithm named MLJA (Model Loading Judgment Algorithm) is proposed in this paper in order to find out visible region of models in the 3D environment. The algorithm integrates the graticules and elevation information to determine the current viewpoint of users in the 3D space. And with the movement of viewpoint, the algorithm schedules the loading of model correspondingly and efficiently.
B. Optimization method of model rendering efficiency
The scheduling method of large-scale 3D building models proposed above is an effective way to solve the problem caused the contradiction between large model data volume and limited capacity of computers. According to the algorithm, we can avoid loading the whole large-scale 3D building models at one time for the sake of limited computer memory, and then improve system efficiency in the procedure of model loading and abandoning. Due to the limited capacity of GPU and local video memory, we need a further research on how to display the loaded model data in more efficient manner. In the remaining part of this paper, the authors will continue to introduce several methods on the optimization of model rendering in the vision cone.
1) Elimination of textures on the backside of models
The backside of the 3D model is invisible to the users. If we omit the texture mapping for the 3D model on the backside, the processing load of graphic card will be reduced as much as at least 50%. Besides, according to an investigation on procedure of actual model rendering, the authors found that on the backside of the 3D model, the invisible texture is rendered in a counter-clockwise manner against the direction of eyesight, while the visible texture mapping is rendered in clockwise manner. So we can omit the rendering of models which is intended to be rendered in
counterclockwise manner. Therefore, the textures won’t exist on the back of 3D models. The graphic card could then work more rapidly and efficiently.
2) Eliminate the shielded model
By calculating the geometric relationship between 3D models in the scene, the shielded models can be omitted while displaying the scene with appropriate shielding patches. Through this way, we can effectively reduce the usage of graphics card memory, and thus achieve higher rendering efficiency and faster 3D virtual system.
In the virtual 3D geographic information system, we often observe 3D models from a high altitude. It is especially true for large-scale outdoor 3D models. The usual arrangement of 3D building models are always sparse, however the real block is very small. Therefore, establishing an index for visual control, which is similar to the BSP tree, doesn’t amount to much. Through carefully stud ying DirectX, we found that we can take advantage of the latest Z-buffering technology of DirectX to implement the shielding control of models.
3) Optimization method of the Shader instructions
In shader 3.0 technology, SM (Shader Model) is a model which can optimize the rendering engine. A 3D scene usually contains several shaders. Among these shaders, some deal with the surfaces and skeletons of buildings, and others deal with the texture of 3D building models.
Geometry can be handled quickly by shader batch process. The shader can combine similar culmination in 3D building models, deal with the correlation operation of a single vertex, determine the physical shape of the model, link the point, line, triangle and other polygons for a rapid processing while create new polygons, etc. We can assign the computing task to shader and local video memory directly in a very short time without bothering the CPU. In this case, visual effects of smoke, explosions and other special effects and complex graphics are no longer necessary to be processed by the CPU of computer. Such features of shader can speed up both the CPU and graphic card in processing huge amount of 3D models.
4) LOD algorithm of large-scale 3D scene
LOD (Level of Detail) is a common and effective solution to resolve the
conflicts between real time visualization and the authenticity of models [8]. By investigating the main features and typical algorithms of LOD technology, the authors proposed a new structure for dynamic multi-level display. This structure not only can be applied to the mesh simplification of models with many different but fixed topologies, but also can be applied to the mesh simplification of models with variable topology. Therefore, the LOD technology can be applied to any grid model. Based on the above concerns, the authors also design a mesh simplification algorithm for variable topology through vertices merge. Via the dual operations of vertex merging and splitting, we can achieve smooth transition across different LOD levels of models, and automatically change the model topology.
These above techniques plays important role in 3D scene. It can not only enable a rapid visualization of large-scale scene, but also can provide a high-resolution display of scene at a local scale with plenty of architectural details.
IV. CONCLUDING REMARKS
Constructing rules and scheduling technology plays an important role in the application of large-scale 3D buildings. Since people’s demand for 3D expression brings a challenge of high-efficiency and high-quality to virtual 3D environment, the methods proposed in this article give a good try in these aspects. According to the authors’ research and case studies in this paper, integration of constructing rules and scheduling technology is promising in providing powerful tools to solve the conflicts between limited processing capacity of computer and massive data of models. The result of our case study on Peking University indicates that the proposed new method on constructing rules and scheduling technology for large-scale 3D scene is highly feasible and efficient in practice. The proposed methods can not only standardize the procedure of model construction, but also can significantly shorten the time taken in scheduling large-scale 3D buildings. It introduces a new effective way to develop applications for large-scale three-dimensional scene.
构建三维建筑模型的规则和调度技术
隋正伟，邬伦, 翁敬农，林星,季晓璐
摘要
三维模型已成为超越了传统的二维地理空间数据的一种重要的地理数据形式。建筑是人类确定其环境的重要标志，因为它们与人类生活密切相关，特别是在市区。地理信息可以用一个更直观、更有效的方式在虚拟的三维环境下能可视化的建筑模型表达出来。建筑模型数据具有数据量庞大、复杂性高、规则不统一等特点。因此，建设大规模场景的成本是很高的。与此同时，电脑缺乏加工大量模型数据的能力。因此，解决计算机有限的处理能力和大量的模型数据之间的矛盾是很有价值的。通过调查建筑物的特点和虚拟的三维环境下视角的规律变化，本文介绍了一些构建三维建筑模型的规则和调度技术，旨在减少数据量和复杂的
模型，从而提高电脑调度大量建筑模型的效率。为了评估在上文中提到的建模规则和调度技术的效率，作者开展了一个案例研究，就是用该方法与传统方法兴建北京大学校园的三维模型。两个结果被审查合格后在模型的数据量、模型的真实性、模型加载的速度、可视化的平均响应时间、兼容性和三维地理可视化平台的可重用性等方面做了对比。China Star，就是一个由本文作者制造的中国自己的三维全球地理信息系统平台。对比结果表明，用所提出的方法建立的模型比那些用传统方法建立的模型更好。对于建造大规模场景的建筑物三维模型，用所提出的方法不仅可以显著地减少模型数据的复杂性和数据量，也可以提高电脑的效率。
关键字：构建规则，模型调度，三维建筑物
一、引言
近年来，随着三维GIS（地理信息系统）软件的发展，例如Google Earth、Skyline、NASA World Wind，具有区域特点的大型三维建筑模型已经成为超越了传统的二维地理空间数据的重要的地理数据形式，如高分辨率遥感影像和矢量数据[1]。相比传统的二维表示形式，地理信息可以用一个更直观、更有效的方式在虚拟的三维环境下能可视化的建筑模型表达出来。三维表示和可视化提供了更好的视觉效果和生动的城市地理信息，从而在人们对他们所处环境的观念中起着重要的作用。同时，三维建筑数据对于数字城市的建设也具有十分重要的意义。
但如何有效地让数以千计的三维建筑模型在一个虚拟的三维环境下可视化并不是一个简单的问题。问题最困难的部分是计算机有限的处理能力和大量的模型数据之间的矛盾，特别是模型渲染的过程。以城市三维建模为例，使用传统的三维建模方法，假设在市区有10万幢建筑物要建模，每个建筑物的模型数据的平均大小约为10兆，所以建造这个城市建筑物模型的总数据量可以达到TB级。然而，普通电脑的内存容量仅是在GB的水平。基于这个担忧，作者提出了对于
大型的三维建筑模型在模型加载和渲染等方面的调度技术。由于缺乏构建规则和标准，建筑模型在构造方法、纹理收集和模型数据量等方面都不尽相同，特别是在模型的可重用性和真实性方面。这种没有统一构建规则的大量数据成为计算机数据存储、处理和可视化一个巨大的挑战。它也带来了不同的三维GIS系统之间的不兼容问题。
经过多年对GIS（地理信息系统）的研究，人们已经积累了大量解决上述问题的方法[3]。然而在虚拟的三维环境下，因为在数据组织和人机交互（HCI）方式的差异，我们需要申请一个新的三维模型的建模和调度的标准化方法。目前，对于三维建筑物的建模并没有一个统一的建设规范或标准。现有的方法对于大型建筑模型的调度是不够的、低效的，从而导致了性能不佳或内存占用大。在回答这些问题时，作者提出了一个构建三维建筑模型的新方法，使用提出的新方法构建的模型可能比那些使用传统方法构建的模型更好。对于建造，用所提出的方法不仅可以显著地减少模型数据的复杂性和数据量，也可以提高模型的可重用性和真实性。考虑到大规模的建筑物模型的调度，本文提出的模型加载判决算法（MLJA）可以解决在三维视觉锥模型加载时的最佳判断问题，特别是在不确定的用户交互的情况下。
本文首先探讨和分析在三维建筑模型的建造和调度步骤中存在的问题，然后作者提出了一套三维建筑模型的建造规则与优化模型的方法。此外，特殊的模型渲染的调度技术和优化方法也适用于本文的大型三维建筑模型。为了评估所提出规则和方法的效率，作者进行了案例研究，使用所提出的方法与传统方法分别构建北京大学主校区和深圳市的三维模型。北京大学主校区和深圳市两个三维模型被审查合格后在模型的数据量、模型的真实性、模型加载的速度、可视化的平均响应时间、兼容性和三维地理可视化平台，如China Star（一个由本文作者制造的中国自己的三维全球地理信息平台）、Skyline等的可重用性等方面做了对比。比较的结果表明，模型提供了类似的真实性，利用我们提出的方法，模型的数据量减少了86％；模型加载的速度增加了70％；模型的可视化和交互速度的平均响应时间减少了83％。同时，如果使用我们的方法建造模型，三维模型数据的兼容性和可重用性也有所改善。
二、三维建筑物建模规则
三维场景是数字城市系统可视化的最佳形式，在建造建筑物的三维模型时，要用正确的而且是考虑到三位建筑模型特点的方法和规则[2]。所建造的模型应该是足够稳健的、可重用的和足够适合于计算机网络传输，并应同时自动适应系统的能力。
一般来说，构建三维建筑模型的方法可分为三种类型：线框模型，曲面模型和实体模型。在一般情况下，以三维的形式进行建筑物建模，建设物的框架首先应根据建筑物的轮廓特征、楼层数、楼层高度、航摄像片、实景真人像片构建。然后，收集要建模的建筑物所代表的场景的特点。重要的特点包括建筑物的航摄像片或实景真人拍摄的照片。最后，将收集的纹理映射到模型框架、优化模型和创建三维建筑模型的数据库。
虽然已经有很多建造三维建筑模型的方法，但我们需要一个统一的建模方法和规则来提高建模的效率、质量、易查性、重用性和归档。通过调查建筑物的特点，我们发现建筑物具有规则的几何形态、不同方向上相似的表面纹理、小规模建筑模型的高度相似性等。基于此，本文从三个方面对建模规则作出了讨论，包括三维建筑模型的建造规则、三维建筑模型的纹理映射规则和我们提到的建模规则基础上的优化方法。
A. 三维建筑模型的建造规则
三维建筑建模是指把真实的建筑物以三维的形式从现实世界到计算机中表现出来的过程[4]。人类，作为模型的的创造者同时又是潜在的使用者，在此过程中发挥着关键的作用。人们对建模对象、建模方法和建模使用的软件工具的理解彼此是不同的。同时开展建模工作的人们之间的这种差异会导致三维模型不同的质量和低效率，因此，本文提到的三维建筑物建模规则对于解决上述问题显得尤为重要，还很有帮助。
1）将相似的楼层作为一个整体，并保持独立的屋顶
2）共享相似的模型，细节特别处理
3）以米为建模单位
4）定义模型的中心点
5）统一模型代码
6）在单一的模型中减少面数
7）减少模型的组合数
8）合理分割模型
B. 三维建筑模型的纹理映射规则
基于三维模型的框架内，要创建一个具有更好可视化效果的三位建筑模型，我们需要合适的纹理。当模型被渲染后，纹理映射的质量直接影响场景的视觉效果[5]。当渲染一个模型时，由于计算机显卡将一起加载所有的纹理，所以纹理映射规则和纹理映射的质量也会直接影响渲染的效率。
C. 建模规则基础上的优化方法
基于建模规则和三维建筑模型的特点，作者开发了一个软件工具来自动优化三维建筑模型。应用到这个软件工具中的优化方法包括：删除模型的内部纹理、合并相邻顶点/线/面，删除未映射的框架等。此外，该软件在优化过程中可以提高整个模型的外形，纹理的位置以及模型的真实性。
三、三维建筑模型的调度技术
对于大型建筑模型的三维可视化，我们要采取一系列的措施以确保高效渲染模型。这些重要的措施包括：现场组织、视力锥切割、消除模型背面的纹理、着色器的优化、LOD算法、数学库优化、内存优化配置等等。
在一个虚拟的三维环境中如何显示数以千计的三维城市建筑物模型是不容易的，主要的问题是模型的调度[7]。它是由模型什么时候怎么样被加载而决定的。这个问题可以分为两个小问题：一个是在三维环境中寻找模型可见的空间区域，另一个是模型渲染效率的优化方法。
A. 在三维环境中查找模型的可见空间区域
在三维可视化和大型三维场景的特点中，根据计算机的操作机制，在加载信号模型或市区单位模型前我们需要先确定当前视点的位置，然后在虚拟的三维环境对视点的规则变化作出反应，系统将自动预加载三维模型数据到内存中去。通过这种方式，可以减少频繁的IO操作，从而系统的整体效率得到提高。本文提出了一种新的算法名为MLJA（型号载入判决算法），为了找出在三维环境中模型的可见空间区域。该算法使三维空间中的十字光标和高程信息变得完整，这样便可以确定用户当前的视点。随着视点的运动，算法有效地调度加载相应的模型。
工业设计专业英语英文翻译
工业设计原著选读 优秀的产品设计 第一个拨号电话1897年由卡罗耳Gantz 第一个拨号电话在1897年被自动电器公司引入，成立于1891年布朗强，一名勘萨斯州承担者。在1889年，相信铃声“中央交换”将转移来电给竞争对手，强发明了被拨号系统控制的自动交换机系统。这个系统在1892年第一次在拉波特完成史端乔系统中被安装。1897年，强的模型电话，然而模型扶轮拨条的位置没有类似于轮齿约170度,以及边缘拨阀瓣。电话，当然是被亚历山大格雷厄姆贝尔（1847—1922）在1876年发明的。第一个商业交换始建于1878（12个使用者），在1879年，多交换机系统由工程师勒罗伊B 菲尔曼发明,使电话取得商业成功,用户在1890年达到250000。 直到1894年，贝尔原批专利过期，贝尔电话公司在市场上有一个虚拟的垄断。他们已经成功侵权投诉反对至少600竞争者。该公司曾在1896年，刚刚在中央交易所推出了电源的“普通电池”制度。在那之前，一个人有手摇电话以提供足够的电力呼叫。一个连接可能仍然只能在给予该人的名义下提出要求达到一个电话接线员。这是强改变的原因。 强很快成为贝尔的强大竞争者。他在1901年引进了一个桌面拨号模型，这个模型在设计方面比贝尔的模型更加清晰。在1902年，他引进了一个带有磁盘拨号的墙面电话，这次与实际指孔，仍然只有170度左右在磁盘周围。到1905年，一个“长距离”手指孔已经被增加了。最后一个强的知名模型是在1907年。强的专利大概过期于1914年，之后他或他的公司再也没有听到过。直到1919年贝尔引进了拨号系统。当他们这样做，在拨号盘的周围手指孔被充分扩展了。 强发明的拨号系统直到1922年进入像纽约一样的大城市才成为主流。但是一旦作为规规范被确立，直到70年代它仍然是主要的电话技术。后按键式拨号在1963年被推出之后，强发明的最初的手指拨号系统作为“旋转的拨号系统”而知名。这是强怎样“让你的手指拨号”的。 埃姆斯椅LCW和DCW 1947 这些带有复合曲线座位，靠背和橡胶防震装置的成型胶合板椅是由查尔斯埃姆斯设计，在赫曼米勒家具公司生产的。 这个原始的概念是被查尔斯埃姆斯（1907—1978）和埃罗沙里宁（1910—1961）在1940年合作构想出来的。在1937年，埃姆斯成为克兰布鲁克学院实验设计部门的领头人，和沙里宁一起工作调查材料和家具。在这些努力下，埃姆斯发明了分成薄片和成型胶合板夹板，被称作埃姆斯夹板，在1941年收到了来自美国海军5000人的订单。查尔斯和他的妻子雷在他们威尼斯，钙的工作室及工厂和埃文斯产品公司的生产厂家一起生产了这批订单。 在1941年现代艺术博物馆，艾略特诺伊斯组织了一场比赛用以发现对现代生活富有想象力的设计师。奖项颁发给了埃姆斯和沙里宁他们的椅子和存储碎片，由包括埃德加考夫曼，大都会艺术博物馆的阿尔弗雷德，艾略特诺伊斯，马尔塞布鲁尔，弗兰克帕里什和建筑师爱德华达雷尔斯通的陪审团裁决。 这些椅子在1946年的现代艺术展览博物馆被展出，查尔斯埃姆斯设计的新的家具。当时，椅子只有三条腿，稳定性问题气馁了大规模生产。 早期的LCW（低木椅）和DWC（就餐木椅）设计有四条木腿在1946年第一次被埃文斯产品公司（埃姆斯的战时雇主）生产出来，被赫曼米勒家具公司分配。这些工具1946年被乔治纳尔逊为赫曼米勒购买，在1949年接手制造权。后来金属脚的愿景在1951年制作，包括LCW（低金属椅）和DWC（就餐金属椅）模型。配套的餐饮和咖啡桌也产生。这条线一直
概率论毕业论文外文翻译
Statistical hypothesis testing Adriana Albu，Loredana Ungureanu Politehnica University Timisoara,adrianaa@aut.utt.ro Politehnica University Timisoara,loredanau@aut.utt.ro Abstract In this article,we present a Bayesian statistical hypothesis testing inspection, testing theory and the process Mentioned hypothesis testing in the real world and the importance of, and successful test of the Notes. Key words Bayesian hypothesis testing; Bayesian inference;Test of significance Introduction A statistical hypothesis test is a method of making decisions using data, whether from a controlled experiment or an observational study (not controlled). In statistics, a result is called statistically significant if it is unlikely to have occurred by chance alone, according to a pre-determined threshold probability, the significance level. The phrase "test of significance" was coined by Ronald Fisher: "Critical tests of this kind may be called tests of significance, and when such tests are available we may discover whether a second sample is or is not significantly different from the first."[1] Hypothesis testing is sometimes called confirmatory data analysis, in contrast to exploratory data analysis. In frequency probability,these decisions are almost always made using null-hypothesis tests. These are tests that answer the question Assuming that the null hypothesis is true, what is the probability of observing a value for the test statistic that is at [] least as extreme as the value that was actually observed?) 2 More formally, they represent answers to the question, posed before undertaking an experiment,of what outcomes of the experiment would lead to rejection of the null hypothesis for a pre-specified probability of an incorrect rejection. One use of hypothesis testing is deciding whether experimental results contain enough information to cast doubt on conventional wisdom. Statistical hypothesis testing is a key technique of frequentist statistical inference. The Bayesian approach to hypothesis testing is to base rejection of the hypothesis on the posterior probability.[3][4]Other approaches to reaching a decision based on data are available via decision theory and optimal decisions. The critical region of a hypothesis test is the set of all outcomes which cause the null hypothesis to be rejected in favor of the alternative hypothesis. The critical region is usually denoted by the letter C. One-sample tests are appropriate when a sample is being compared to the population from a hypothesis. The population characteristics are known from theory or are calculated from the population.
毕业论文外文翻译模版
吉林化工学院理学院 毕业论文外文翻译English Title（Times New Roman ，三号） 学生学号：08810219 学生姓名：袁庚文 专业班级：信息与计算科学0802 指导教师：赵瑛 职称副教授 起止日期：2012.2.27～2012.3.14 吉林化工学院 Jilin Institute of Chemical Technology
1 外文翻译的基本内容 应选择与本课题密切相关的外文文献（学术期刊网上的），译成中文，与原文装订在一起并独立成册。在毕业答辩前，同论文一起上交。译文字数不应少于3000个汉字。 2 书写规范 2.1 外文翻译的正文格式 正文版心设置为：上边距：3.5厘米，下边距：2.5厘米，左边距：3.5厘米，右边距：2厘米，页眉：2.5厘米，页脚：2厘米。 中文部分正文选用模板中的样式所定义的“正文”，每段落首行缩进2字；或者手动设置成每段落首行缩进2字，字体：宋体，字号：小四，行距：多倍行距1.3，间距：前段、后段均为0行。 这部分工作模板中已经自动设置为缺省值。 2.2标题格式 特别注意：各级标题的具体形式可参照外文原文确定。 1．第一级标题（如：第1章绪论）选用模板中的样式所定义的“标题1”，居左；或者手动设置成字体：黑体，居左，字号：三号，1.5倍行距，段后11磅，段前为11磅。 2．第二级标题（如：1.2 摘要与关键词）选用模板中的样式所定义的“标题2”，居左；或者手动设置成字体：黑体，居左，字号：四号，1.5倍行距，段后为0，段前0.5行。 3．第三级标题（如：1.2.1 摘要）选用模板中的样式所定义的“标题3”，居左；或者手动设置成字体：黑体，居左，字号：小四，1.5倍行距，段后为0，段前0.5行。 标题和后面文字之间空一格（半角）。 3 图表及公式等的格式说明 图表、公式、参考文献等的格式详见《吉林化工学院本科学生毕业设计说明书（论文）撰写规范及标准模版》中相关的说明。
工业设计外文翻译
Interaction design Moggridge Bill Interaction design，Page 1-15 USA Art Press, 2008 Interaction design (IxD) is the study of devices with which a user can interact, in particular computer users. The practice typically centers on "embedding information technology into the ambient social complexities of the physical world."[1] It can also apply to other types of non-electronic products and services, and even organizations. Interaction design defines the behavior (the "interaction") of an artifact or system in response to its users. Malcolm McCullough has written, "As a consequence of pervasive computing, interaction design is poised to become one of the main liberal arts of the twenty-first century." Certain basic principles of cognitive psychology provide grounding for interaction design. These include mental models, mapping, interface metaphors, and affordances. Many of these are laid out in Donald Norman's influential book The Psychology of Everyday Things. As technologies are often overly complex for their intended target audience, interaction design aims to minimize the learning curve and to increase accuracy and efficiency of a task without diminishing usefulness. The objective is to reduce frustration and increase user productivity and satisfaction. Interaction design attempts to improve the usability and experience of the product, by first researching and understanding certain users' needs and then designing to meet and exceed them. (Figuring out who needs to use it, and how those people would like to use it.) Only by involving users who will use a product or system on a regular basis will designers be able to properly tailor and maximize usability. Involving real users, designers gain the ability to better understand user goals and experiences. (see also: User-centered design) There are also positive side effects which include enhanced system capability awareness and user ownership. It is important that the user be aware of system capabilities from an early stage so that expectations regarding functionality are both realistic and properly understood. Also, users who have been active participants in a product's development are more likely to feel a sense of ownership, thus increasing overall satisfa. Instructional design is a goal-oriented, user-centric approach to creating training and education software or written materials. Interaction design and instructional design both rely on cognitive psychology theories to focus on how users will interact with software. They both take an in-depth approach to analyzing the user's needs and goals. A needs analysis is often performed in both disciplines. Both, approach the design from the user's perspective. Both, involve gathering feedback from users, and making revisions until the product or service has been found to be effective. (Summative / formative evaluations) In many ways, instructional
毕业论文外文翻译模板
农村社会养老保险的现状、问题与对策研究社会保障对国家安定和经济发展具有重要作用，“城乡二元经济”现象日益凸现，农村社会保障问题客观上成为社会保障体系中极为重要的部分。建立和完善农村社会保障制度关系到农村乃至整个社会的经济发展，并且对我国和谐社会的构建至关重要。我国农村社会保障制度尚不完善，因此有必要加强对农村独立社会保障制度的构建，尤其对农村养老制度的改革，建立健全我国社会保障体系。从户籍制度上看，我国居民养老问题可分为城市居民养老和农村居民养老两部分。对于城市居民我国政府已有比较充足的政策与资金投人，使他们在物质和精神方面都能得到较好地照顾，基本实现了社会化养老。而农村居民的养老问题却日益突出，成为摆在我国政府面前的一个紧迫而又棘手的问题。 一、我国农村社会养老保险的现状 关于农村养老，许多地区还没有建立农村社会养老体系，已建立的地区也存在很多缺陷，运行中出现了很多问题，所以完善农村社会养老保险体系的必要性与紧迫性日益体现出来。 （一）人口老龄化加快 随着城市化步伐的加快和农村劳动力的输出，越来越多的农村青壮年人口进入城市，年龄结构出现“两头大，中间小”的局面。中国农村进入老龄社会的步伐日渐加快。第五次人口普查显示：中国65岁以上的人中农村为5938万，占老龄总人口的67.4%.在这种严峻的现实面前，农村社会养老保险的徘徊显得极其不协调。 （二）农村社会养老保险覆盖面太小 中国拥有世界上数量最多的老年人口，且大多在农村。据统计，未纳入社会保障的农村人口还很多，截止2000年底，全国7400多万农村居民参加了保险，占全部农村居民的11.18%，占成年农村居民的11.59%.另外，据国家统计局统计，我国进城务工者已从改革开放之初的不到200万人增加到2003年的1.14亿人。而基本方案中没有体现出对留在农村的农民和进城务工的农民给予区别对待。进城务工的农民既没被纳入到农村养老保险体系中，也没被纳入到城市养老保险体系中，处于法律保护的空白地带。所以很有必要考虑这个特殊群体的养老保险问题。
大学毕业论文---软件专业外文文献中英文翻译
软件专业毕业论文外文文献中英文翻译 Object landscapes and lifetimes Tech nically, OOP is just about abstract data typing, in herita nee, and polymorphism, but other issues can be at least as importa nt. The rema in der of this sect ion will cover these issues. One of the most importa nt factors is the way objects are created and destroyed. Where is the data for an object and how is the lifetime of the object con trolled? There are differe nt philosophies at work here. C++ takes the approach that con trol of efficie ncy is the most importa nt issue, so it gives the programmer a choice. For maximum run-time speed, the storage and lifetime can be determined while the program is being written, by placing the objects on the stack (these are sometimes called automatic or scoped variables) or in the static storage area. This places a priority on the speed of storage allocatio n and release, and con trol of these can be very valuable in some situati ons. However, you sacrifice flexibility because you must know the exact qua ntity, lifetime, and type of objects while you're writing the program. If you are trying to solve a more general problem such as computer-aided desig n, warehouse man ageme nt, or air-traffic con trol, this is too restrictive. The sec ond approach is to create objects dyn amically in a pool of memory called the heap. In this approach, you don't know un til run-time how many objects you n eed, what their lifetime is, or what their exact type is. Those are determined at the spur of the moment while the program is runnin g. If you n eed a new object, you simply make it on the heap at the point that you n eed it. Because the storage is man aged dyn amically, at run-time, the amount of time required to allocate storage on the heap is sig ni fica ntly Ion ger tha n the time to create storage on the stack. (Creat ing storage on the stack is ofte n a si ngle assembly in structio n to move the stack poin ter dow n, and ano ther to move it back up.) The dyn amic approach makes the gen erally logical assumpti on that objects tend to be complicated, so the extra overhead of finding storage and releas ing that storage will not have an importa nt impact on the creati on of an object .In additi on, the greater flexibility is esse ntial to solve the gen eral program ming problem. Java uses the sec ond approach, exclusive". Every time you want to create an object, you use the new keyword to build a dyn amic in sta nee of that object. There's ano ther issue, however, and that's the lifetime of an object. With Ian guages that allow objects to be created on the stack, the compiler determines how long the object lasts and can automatically destroy it. However, if you create it on the heap the compiler has no kno wledge of its lifetime. In a Ianguage like C++, you must determine programmatically when to destroy the
文献综述和外文翻译撰写要求与格式规范
本科毕业论文（设计）文献综述和外文翻译 撰写要求与格式规范 一、毕业论文（设计）文献综述 （一）毕业论文（设计）文献综述的内容要求 1．封面：由学院统一设计，普通A4纸打印即可。 2.正文 综述正文部分需要阐述所选课题在相应学科领域中的发展进程和研究方向，特别是近年来的发展趋势和最新成果。通过与中外研究成果的比较和评论，说明自己的选题是符合当前的研究方向并有所进展，或采用了当前的最新技术并有所改进，目的是使读者进一步了解本课题的意义。文中的用语、图纸、表格、插图应规范、准确，量和单位的使用必须符合国家标准规定，引用他人资料要有标注。 文献综述字数在5000字以上。 正文前须附500字左右中文摘要，末尾须附参考文献。 参考文献的著录按在文献综述中出现的先后顺序编号。 期刊类文献书写方法:[序号]作者（不超过3人，多者用等表示）.题（篇）名[J].刊名,出版年,卷次（期次）:起止页次.
图书类文献书写方法:[序号]作者.书名[M].版本.出版地:出版者,出版年:起止页次. 论文集类文献书写方法:[序号]作者.篇名[C].论文集名.出版地:出版者,出版年:起止页次. 学位论文类书写方法:[序号]作者.篇名[D].出版地:单位名称,年份. 电子文献类书写方法:[序号]主要责任者. 题名:其他题名信息[文献类型标志/文献载体标志 ]出版地:出版者,出版年（更新或修改日期）[引用日期].获取和访问途径. 参考文献篇数应符合学院毕业论文（设计）工作的要求。 （二）毕业论文（设计）文献综述撰写与装订的格式规范 第一部分：封面 1.封面：由学院统一设计，“本科生毕业论文（设计）”根据作业实际明确为“论文”或“设计”，其它文本、表格遇此类情况同样处理。 第二部分：文献综述主题 1.中文摘要与关键词 摘要标题（五号，宋体，顶格，加粗）
工业设计产品设计中英文对照外文翻译文献
(文档含英文原文和中文翻译) 中英文翻译原文：
DESIGN and ENVIRONMENT Product design is the principal part and kernel of industrial design. Product design gives uses pleasure. A good design can bring hope and create new lifestyle to human. In spscificity,products are only outcomes of factory such as mechanical and electrical products,costume and so on.In generality,anything,whatever it is tangibile or intangible,that can be provided for a market,can be weighed with value by customers, and can satisfy a need or desire,can be entiled as products. Innovative design has come into human life. It makes product looking brand-new and brings new aesthetic feeling and attraction that are different from traditional products. Enterprose tend to renovate idea of product design because of change of consumer's lifestyle , emphasis on individuation and self-expression,market competition and requirement of individuation of product. Product design includes factors of society ,economy, techology and leterae humaniores. Tasks of product design includes styling, color, face processing and selection of material and optimization of human-machine interface. Design is a kind of thinking of lifestyle.Product and design conception can guide human lifestyle . In reverse , lifestyle also manipulates orientation and development of product from thinking layer.
毕业论文 外文翻译#(精选.)
毕业论文（设计）外文翻译 题目：中国上市公司偏好股权融资：非制度性因素 系部名称：经济管理系专业班级:会计082班 学生姓名：任民学号： 200880444228 指导教师：冯银波教师职称:讲师 年月日
译文： 中国上市公司偏好股权融资：非制度性因素 国际商业管理杂志 2009.10 摘要：本文把重点集中于中国上市公司的融资活动，运用西方融资理论，从非制度性因素方面，如融资成本、企业资产类型和质量、盈利能力、行业因素、股权结构因素、财务管理水平和社会文化，分析了中国上市公司倾向于股权融资的原因，并得出结论，股权融资偏好是上市公司根据中国融资环境的一种合理的选择。最后，针对公司的股权融资偏好提出了一些简明的建议。 关键词：股权融资，非制度性因素，融资成本 一、前言 中国上市公司偏好于股权融资，根据中国证券报的数据显示，1997年上市公司在资本市场的融资金额为95.87亿美元，其中股票融资的比例是72.5％，，在1998年和1999年比例分别为72.6％和72.3％，另一方面，债券融资的比例分别是17.8％，24.9％和25.1％。在这三年，股票融资的比例，在比中国发达的资本市场中却在下跌。以美国为例，当美国企业需要的资金在资本市场上，于股权融资相比他们宁愿选择债券融资。统计数据显示，从1970年到1985年，美日企业债券融资占了境外融资的91.7％，比股权融资高很多。阎达五等发现，大约中国3/4的上市公司偏好于股权融资。许多研究的学者认为，上市公司按以下顺序进行外部融资：第一个是股票基金，第二个是可转换债券，三是短期债务，最后一个是长期负债。许多研究人员通常分析我国上市公司偏好股权是由于我们国家的经济改革所带来的制度性因素。他们认为，上市公司的融资活动违背了西方古典融资理论只是因为那些制度性原因。例如，优序融资理论认为，当企业需要资金时，他们首先应该转向内部资金（折旧和留存收益），然后再进行债权融资，最后的选择是股票融资。在这篇文章中，笔者认为，这是因为具体的金融环境激活了企业的这种偏好，并结合了非制度性因素和西方金融理论，尝试解释股权融资偏好的原因。
中英文论文对照格式
英文论文APA格式 英文论文一些格式要求与国内期刊有所不同。从学术的角度讲，它更加严谨和科学，并且方便电子系统检索和存档。 版面格式
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毕业论文外文翻译模版
长江大学工程技术学院 毕业设计（论文）外文翻译 外 文 题 目 Matlab Based Interactive Simulation Program for 2D Multisegment Mechanical Systems 译 文 题 目 二维多段机械系统基于Matlab 的 交互式仿真程序 系 部 化学工程系 专 业 班 级 化工60801 学 生 姓 名 李泽辉 指 导 教 师 张 铭 辅 导 教 师 张 铭 完 成 日 期 2012.4.15 顶层配置在管路等，要求设备，所有设要求，对调整使案，编是指机确保机组中资料试
外文翻译 二维多段机械系统基于Matlab 的交互式仿真程序 Henryk Josiński, Adam ?witoński, Karol J?drasiak 著；李泽辉 译 摘要：本文介绍了多段机械系统设计原则，代表的是一个模型的一部分的设计系统，然后扩展 形成的几个部分和模型算法的分类与整合的过程，以及简化步骤的过程叫多段系统。本文还介绍了设计过程的二维多段机械系统的数字模型，和使用Matlab 的软件包来实现仿真。本文还讨论测试运行了一个实验，以及几种算法的计算，实现了每个单一步骤的整合。 1 简介 科学家创造了物理模型和数学模型来表示人类在运动中的各种形式。数学模型 使创建数字模型和进行计算机仿真成为可能。模型试验，可以使人们不必真正的实 验就可以虚拟的进行力和力矩的分解。 本文研究的目的是建立一个简单的多段运动模型，以增加模型的连续性和如何 避免不连续为原则。这是创建一个人类运动模型系统的冰山一角。其使用matlab 程 序包创建的数字模型，可以仿真人类运动。 文献中关于这一主题的内容很广泛。运动的模式和力矩的分解在这些文献中都 有涉猎。动态的平面人体运动模型，提出了解决了迭代矩阵的方法。还值得一提的 是这类项目的参考书目，布鲁贝克等人提出了一个模型——人腿模型，这个以人的 物理运动为基础的平面模型仿真了人腿——一个单一的扭簧和冲击碰撞模型。人腿 模型虽然简单，但是它展示人类的步态在水平地面上的运动特征。布鲁贝克等人还 介绍，在人腿模型的双足行走的基础上，从生物力学的角度而言，符合人体步行的 特征。这个模型具有一个躯干，双腿膝盖和脚踝。它能够合理的表现出人多样的步 态风格。一个仿真人类运动的数学模型反应出了人的部分运动状态。 图1. 力的分解 2 力的分解
电子信息工程专业毕业论文外文翻译中英文对照翻译
本科毕业设计（论文）中英文对照翻译 院（系部）电气工程与自动化 专业名称电子信息工程 年级班级 04级7班 学生姓名 指导老师
Infrared Remote Control System Abstract Red outside data correspondence the technique be currently within the scope of world drive extensive usage of a kind of wireless conjunction technique,drive numerous hardware and software platform support. Red outside the transceiver product have cost low, small scaled turn, the baud rate be quick, point to point SSL, be free from electromagnetism thousand Raos etc.characteristics, can realization information at dissimilarity of the product fast, convenience, safely exchange and transmission, at short distance wireless deliver aspect to own very obvious of advantage.Along with red outside the data deliver a technique more and more mature, the cost descend, red outside the transceiver necessarily will get at the short distance communication realm more extensive of application. The purpose that design this system is transmit cu stomer’s operation information with infrared rays for transmit media, then demodulate original signal with receive circuit. It use coding chip to modulate signal and use decoding chip to demodulate signal. The coding chip is PT2262 and decoding chip is PT2272. Both chips are made in Taiwan. Main work principle is that we provide to input the information for the PT2262 with coding keyboard. The input information was coded by PT2262 and loading to high frequent load wave whose frequent is 38 kHz, then modulate infrared transmit dioxide and radiate space outside when it attian enough power. The receive circuit receive the signal and demodulate original information. The original signal was decoded by PT2272, so as to drive some circuit to accomplish