A generative design technique for exploring shape variations

Because innovative and creative design is essential to a successful product, this work brings the benefits of generative design in the conceptual phase of the product development process so that designers/engineers can effectively explore and create ingenious designs and make better design decisions. We proposed a state-of-the-art generative design technique (GDT), called Space-filling-GDT (Sf-GDT), for the creation of innovative designs. The proposed Sf-GDT has the ability to create variant optimal design alternatives for a given computer-aided design (CAD) model. An effective GDT should generate design alternatives that cover the entire design space. Toward that end, the criterion of space-filling is utilized, which uniformly distribute designs in the design space thereby giving a designer a better understanding of possible design options. To avoid creating similar designs, a weighted-grid-search approach is developed and integrated into the Sf-GDT. One of the core contributions of this work lies in the ability of Sf-GDT to explore hybrid design spaces consisting of both continuous and discrete parameters either with or without geometric constraints. A parameter-free optimization technique, called Jaya algorithm, is integrated into the Sf-GDT to generate optimal designs. Three different design parameterization and space formulation strategies; explicit, interactive, and autonomous, are proposed to set up a promising search region(s) for optimization. Two user interfaces; a web-based and a Windows-based, are also developed to utilize Sf-GDT with the existing CAD software having parametric design abilities. Based on the experiments in this study, Sf-GDT can generate creative design alternatives for a given model and outperforms existing state-of-the-art techniques.     

Data-driven generative design for mass customization: A case study

Generative design provides a promising algorithmic solution for mass customization of products, improving both product variety and design efficiency. However, the current designer-driven generative design formulates the automated program in a manual manner and has insufficient ability to satisfy the diverse needs of individuals. In this work, we propose a data-driven generative design framework by integrating multiple types of data to improve the automation level and performance of detail design to boost design efficiency and improve user satisfaction. A computational workflow including automated shape synthesis and structure design methods is established. More specifically, existing designs selected based on user preferences are utilized in the shape synthesis for creating generative models. For structural design, user-product interaction data gathered by sensors are used as inputs for controlling the spatial distributions of heterogeneous lattice structures. Finally, the proposed concept and workflow are demonstrated with a bike saddle design with a personalized shape and inner structures to be manufactured with additive manufacturing.     

A prototype system for early geometric configuration design

In this paper, we present a prototype system that has been developed to support geometric configuration of objects at the early stages of design. Guided by the general principle of minimum commitment, this system assists in the iterative development of alternative geometric configurations based on approximately or precisely defined information. The system has been evaluated in the context of computer enclosure design.     

Computer-based instruction and generative strategies: Conceptual framework & illustrative example

Adult students who are enrolled in higher education must experience computer-based instruction that is well-designed in terms of both efficiency and relevance. Published practical examples of processes that will result in such instruction are rare. This article begins by describing the needs of adult students who are enrolled in higher education. Then, this article describes a project in which Morrison, Ross, and Kemp’s (2004) curvilinear instructional design model was used to create computer-based instruction in the field of developmental mathematics. Both the design and development phases are described. The article concludes with implications for others who might use a similar approach in higher education.     

平面参数曲线的自由变形

提出一种全新的参数曲线自由变形方法:基于平面矢量叠加原理构造出特殊的伸缩矢量函数去作用待变形曲线,从而使曲线发生形变,通过改变曲线上型值点的位置和个数以及每个型值点处的权因子可达到预期的变形效果.实验表明,该方法数学背景简单、易于控制,重复使用可获得丰富的变形效果,适用于几何造型和计算机动画等领域.     

A methodology for brand feature establishment based on the decomposition and reconstruction of a feature curve

For creative products, maintaining original brand elements and features in a new product is an important issue in the design process as brand features are conceived and generated for longevity. However, current methods rely on designers’ abilities, and the size of forms is easily affected when shape morphing is applied, causing limitations in computer-aided design. In order to focus on design while preserving key features, a systematic method for presenting brand features is proposed in this article. In this method, the feature curves of the brand features of a company are decomposed with defined feature parameters, which were then used to reconstruct the feature curve of the designed product in the design stage by using a residual modified gray prediction model. A classic vehicle configuration design is taken as an example to show the implementation procedure of the proposed method. With residual modification, this method can also assimilate other forms from the original form database, and generate new forms based on gray prediction. The results show that brand features can be retained in the newly designed product based on the proposed method. Though vehicle design is taken as the example, this method can also be used to develop designs for many other the brand features. For classic products with historical value, this method can generate new forms that maintain original brand features, thereby satisfying customers’ needs for brand authenticity.     

Computer aids for floodlighting design

The lighting engineer is faced with many problems when specifying floodlighting schemes, not least the large amount of computation required to evaluate each potential solution in terms of illuminance grids and isolux contours across the area of interest. Traditionally these kinds of evaluations have been carried out on (programmable) calculators with a design time days for anything other than trivial schemes. Mainframe computers are used in batch mode to ease this problem, but there is a need for an interactive system directly available in the design office. Interactive desk-top microcomputers with graphics facilities make this kind of system both technically and economically viable for the small design office. This paper describes the recently implemented system at Abacus Municipal Ltd, a company involved in the design, supply, and installation of a wide range of floodlighting systems. The primary objective is to provide the lighting engineer with a simple interactive computer system for specifying the details of a floodlighting scheme, leaving the computer to perform the relatively simple but tedious calculations to determine the illumination over the area of interest. User interaction in terms familiar to the lighting engineer is considered to be important so that the engineer's skills, knowledge and experience are enhanced rather than replaced. The design time using the system is typically reduced to a matter of hours rather than days, and improved and more precise results can be presented to the potential client.     

Variant design for mechanical artifacts: A state-of-the-art survey

Variant design refers, to the technique of adapting existing design specifications to satisfy new design goals and constraints. Specific support of variant design techniques in current computer aided design systems would help to realize a rapid response manufacturing environment. A survey of approaches supporting variant design is presented. Capabilities used in current commercial computer aided design systems are discussed along with approaches used in recent research efforts. Information standards applicable to variant design are also identified. Barriers to variant design in current systems are identified and ideas are presented for augmentation of current systems to support variant design.     

计算机辅助概念设计研究进展

以第4届国际计算机辅助工业设计与概念设计会议为背景，阐明了产品概念设计的内涵，指出计算机辅助概念设计CACD要解决的三大问题：概念设计方法学、产品信息模型及求解方法、计算机辅助概念设计技术；进而从智能概念设计技术、协同概念设计技术、虚拟概念设计技术、需求驱动概念设计技术等多个方面总结了CACD技术的研究进展，最后指出了CACD的发展趋势，并提出了CACD的三层架构．     

A spatial warping method for freeform modeling based on a level-set method

Providing an intuitive and effective tool for freeform geometric modeling is important for product design. We introduce in this paper a level-set based spatial warping method for freeform modeling, allowing shape deformation to be initialed by rigid body transformations of volumetric tools. Intuitive user operations including imprinting, deformation and smoothing are developed to shield the user from the underlying geometric complexity. Unlike mesh-based spatial warping methods, the developed method represents a digital model by implicit distance field data and describes its change of geometry by the level-set method. This guarantees the generation of topologically correct triangular mesh models and circumvents the error-prone remeshing and mesh-repairing processes, thus preventing topological errors such as self-intersections. We present this method with algorithm details, numerical experiments and modeling examples.     

多层次结构生成对抗网络的文本生成图像方法

近年来,生成对抗网络（GAN）在从文本描述到图像的生成中已经取得了显著成功,但仍然存在图像边缘模糊、局部纹理不清晰以及生成样本方差小等问题。针对上述不足,在叠加生成对抗网络模型（StackGAN++）基础上,提出了一种多层次结构生成对抗网络（MLGAN）模型,该网络模型由多个生成器和判别器以层次结构并列组成。首先,引入层次结构编码方法和词向量约束来改变网络中各层次生成器的条件向量,使图像的边缘细节和局部纹理更加清晰生动;然后,联合训练生成器和判别器,借助多个层次的生成图像分布共同逼近真实图像分布,使生成样本方差变大,增加生成样本的多样性;最后,从不同层次的生成器生成对应文本的不同尺度图像。实验结果表明,在CUB和Oxford-102数据集上MLGAN模型的Inception score分别达到了4.22和3.88,与StackGAN++相比,分别提高了4.45%和3.74%。MLGAN模型在解决生成图像的边缘模糊和局部纹理不清晰方面有了一定提升,其生成的图像更接近真实图像。     

用MATLAB设计及FPGA实现FIR滤波器的方法

FIR滤波器是一种被广泛应用的基本的数字信号处理部件。针对采用常用的软、硬件方法设计实现FIR滤波器存在的问题，提出采用MATLAB的窗函数方法设计并在FPGA上高效实现严格线性相位FIR滤波器的方案。通过编程调试得到满意的结果。该方法实现FIR滤波器器件体积小、性能可靠、价格低廉、设计周期短，可作为高速数字滤波设计的较好方案。     

在计算机辅助设计中油田可采储量的预测方法初探

本文论述了在计算机辅助设计中油田各阶段可采储量的预测方法．为实现油田生产与安排系统的实现提供科学的预测方法。关键词：计算机辅助设计：油田生产：储量;预测方法     

Evolutionary-computer-assisted design of image operators that detect interest points using genetic programming

This work describes a way of designing interest point detectors using an evolutionary-computer-assisted design approach. Nowadays, feature extraction is performed through the paradigm of interest point detection due to its simplicity and robustness for practical applications such as: image matching and view-based object recognition. Genetic programming is used as the core functionality of the proposed human-computer framework that significantly augments the scope of interest point design through a computer assisted learning process. Indeed, genetic programming has produced numerous interest point operators, many with unique or unorthodox designs. The analysis of those best detectors gives us an advantage to achieve a new level of creative design that improves the perspective for human-machine innovation. In particular, we present two novel interest point detectors produced through the analysis of multiple solutions that were obtained through single and multi-objective searches. Experimental results using a well-known testbed are provided to illustrate the performance of the operators and hence the effectiveness of the proposal.     

Automatic surface generation in computer aided design

A technique for smoothly blending algebraic surfaces and a language for syntactic specification of objects are developed. Their use in automated design is illustrated by a gate valve example in which all fillets, edge roundings and joining surfaces are automatically constructed. The resulting object has an internal representation that is particularly amenable to interactive editing.This work was supported in part by the National Science Foundation under grant ECS 83-12096 and MCS 82-17996     

Generation of energy-efficient architecture solutions applying GENE_ARCH: An evolution-based generative design system

As the field of design automation and generative design systems (GDS) evolve, more emphasis is placed on issues of design evaluation. This paper focus on the presentation of different applications of GENE_ARCH, an evolution-based GDS aimed at helping architects to achieve energy-efficient and sustainable architectural solutions. The system applies goal-oriented design, combining a genetic algorithm (GA) as the search engine, with the DOE2.1E building energy simulation software as the evaluation module. Design evaluation is based on energy spent for heating, cooling, ventilation and artificial lighting in the building, and on sustainability issues like greenhouse gas emissions associated with the embodied energy of construction materials. The GA can work either as a standard GA or as a Pareto GA, for multicriteria search and optimization. In order to provide a broad view of the capabilities of the software, different applications are discussed: (1) standard GA: testing and validating the software; (2) standard GA: incorporation of architecture design intentions, using a building by architect Alvaro Siza; (3) Pareto GA: choice of construction materials, considering cost, building energy use, and embodied energy; (4) Pareto GA: application to Siza’s building, considering thermal and lighting behavior separately; (5) standard GA: shape generation with single objective function; (6) Pareto GA: shape generation with multicriteria evaluation; (7) Pareto GA: application to an urban and housing context. Overall conclusions from the different applications are discussed, as well as current challenges and limitations, and directions for further work.     

注塑机合模机构设计软件的开发研究

针对注塑机机械合模机构,以自动化设计为目标,集成数据管理、机构参数优化与特性分析、三维运动模拟、有限元分析和零件库的软件开发.该软件可有效地提高设计人员的分析能力和设计效率.     

Periodic surface modeling for computer aided nano design

Current solid and surface modeling methods based on Euclidean geometry in traditional computer aided design are not efficient in constructing a large number of atoms and particles. In this paper, we propose a periodic surface model for computer aided nano design such that geometry of atoms and molecules can be constructed parametrically. At the molecular scale, periodicity of the model allows thousands of particles to be built efficiently. At the meso scale, inherent porosity of the model represents natural morphology of polymer and macromolecule. Surface and volume operations are defined to support crystal and molecular model creation with loci and foci periodic surfaces. The ultimate goal is to enable computer assisted material and system design at atomic, molecular, and meso scales.