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Study on construction of freeform feature models with attachment and validity maintenance

SUN Li-juan,LI Mo,

计算机应用研究 , 2009,
Abstract: This paper introduced the freeform feature modeling in HUST-CAID, defined classification and parameters combining with the HUST-CAID system (computer aided industry design system developed by Harbin University of Science and Technology), creating a freeform feature by this classification and parameterization. On the basis of configuration of FFDP,put forward a framework for attaching freeform feature. The framework can make freeform feature model be parameterization. Then, on the basis of the framework, this paper researched a validity maintenance for the freeform feature with attachment, which could keep the validity of freeform feature with attachment.
Research on constraints resolving for freeform feature model

计算机应用研究 , 2010,
Abstract: This paper proposed a new technology of constraint resolving based on parameterization of freeform feature model. In this method, parameterized freeform feature definition point, established geometry constraint graph, decomposed constraint problem into triangle constraint and tetrahedron constraint, and solved each of them, constructed sub-problem as global result by using handedness rule. This arithmetic was implemented in the HUST-CAIDS, and the result model can meet designer requirement.
Numeric and curve parameters for freeform surface feature models

SUN Li-juan,XIE Li-qiang,SUN Da-songb,

计算机应用研究 , 2009,
Abstract: A successful feature modeling system, largely depends on whether it can provide a user-friendly way to specify and change feature models. Aiming at this point, this paper introduced several new facilities. The first, presented numeric and curve parameters for specification and variation of freeform surface feature models. The second, other parameters could be added to a feature model, including intersection curves between features. To provide these facilities, introduced a new three-level structure, which included three parts, the highest level, called the unevaluated model, the lowest level of the feature model was the evaluated model, a new intermediate level, called the partially evaluated model. The latter linked the features at the highest level to the geometric model at the lowest level, but also intersectioned between features to both their definitions at the highest level and the geometric model at the lowest level.
Design and development of a freeform active mirror for an astronomy application  [PDF]
Zalpha Challita,Tibor Agócs,Emmanuel Hugot,Attila Jaskó,Gabby Kroes,William Taylor,Chris Miller,Hermine Schnetler,Lars Venema,Laszlo Mosoni,David Le Mignant,Marc Ferrari,Jean-Gabriel Cuby
Physics , 2014, DOI: 10.1117/1.OE.53.3.031311
Abstract: The advent of extremely large telescopes will bring unprecedented light-collecting power and spatial resolution, but it will also lead to a significant increase in the size and complexity of focal-plane instruments. The use of freeform mirrors could drastically reduce the number of components in optical systems. Currently, manufacturing issues limit the common use of freeform mirrors at short wavelengths. This article outlines the use of freeform mirrors in astronomical instruments with a description of two efficient freeform optical systems. A new manufacturing method is presented which seeks to overcome the manufacturing issues through hydroforming of thin polished substrates. A specific design of an active array is detailed, which will compensate for residual manufacturing errors, thermoelastic deformation, and gravity-induced errors during observations. The combined hydroformed mirror and the active array comprise the Freeform Active Mirror Experiment, which will produce an accurate, compact, and stable freeform optics dedicated to visible and near-infrared observations.
New efficient optimal mass transport approach for single freeform surface design  [PDF]
Christoph B?sel,Herbert Gross
Physics , 2015,
Abstract: We present a new optimal mass transport approach for the design of a continuous single freeform surface for collimated beams. By applying the law of reflection/refraction and the well-known integrability condition, it is shown that the design process in a small angle approximation can be decoupled into the calculation of a raymapping by optimal mass transport methods and the subsequent construction of the freeform surface by a steady linear advection equation. It is shown that the solution of this linear advection equation can be obtained by a decomposition into two dimensional subproblems and solving these by standard integrals. The efficiency of the method is demonstrated by applying it to two challenging design examples.
Distinguishing Feature, Quality, Originality and Utility--the Base of Technical Journals

Min Jiahua,

中国科技期刊研究 , 1999,
Abstract: 提出特、高、新、用是技术期刊立足之本的论点,阐明了特、高、新、用的概念,是读者的需要,是实现技术期刊导向功能的途径。编辑在组稿、选稿、审稿中把握特、高、新、用的要求,在编、排、印、校中实施全方位全过程监控,是期刊全面质量的保证。
Freeform high-speed large-amplitude deformable Piezo Mirrors  [PDF]
Matthias C Wapler,Jens Brunne,Ulrike Wallrabe
Physics , 2013, DOI: 10.1109/OMN.2013.6659107
Abstract: We present a new type of tunable mirror with sharply-featured freeform displacement profiles, large displacements of several 100\mu m and high operating frequencies close to the kHz range at 15mm diameter. The actuation principle is based on a recently explored "topological" displacement mode of piezo sheets. The prototypes presented here include a rotationally symmetric axicon, a hyperbolic sech-icon and a non-symmetric pyram-icon and are scalable to smaller dimensions. The fabrication process is economic and cleanroom-free, and the optical quality is sufficient to demonstrate the diffraction patterns of the optical elements.
Classification of the Sick Organise Based on the Feature of Fractal Dim ension

Zeng Falong,Wang Sixian,LiFeipeng,Wang Liand He Chu,

中国图象图形学报 , 1999,
Abstract: 按照Mandelbrot的分形理论,医学图象及许多自然图象的灰度表面的形成均符合分形布朗运动规律,而且可以用分形的维数来表征图象灰度表面的精细与粗糙程度。文中正是基于这种思想,采用图象的分形维数作为一个特征参量,对人体的肌肉组织进行超声定征。对60 多个样本三类病变图象提取分形维数,并采用基于Bayes法则的分类器分类,实验表明:用分形维数对组织进行定征,正确率达88.33% 。这为医学的临床辅助诊断提供了一种新的参考量,对提高病变诊断的正确率有重大的意义
An Image Stabilization Optical System Using Deformable Freeform Mirrors  [PDF]
Qun Hao,Xuemin Cheng,Jiqiang Kang,Yuhua Jiang
Sensors , 2015, DOI: 10.3390/s150101736
Abstract: An image stabilization optical system using deformable freeform mirrors is proposed that enables the ray sets to couple dynamically in the object and image space. It aims to correct image blurring and degradation when there is relative movement between the imaging optical axis and the object. In this method, Fermat’s principle and matrix methods are used to describe the optical path of the entire optical system with a shift object plane and a fixed corresponding image plane in the carrier coordinate system. A constant optical path length is determined for each ray set, so the correspondence between the object and the shift free image point is used to calculate the solution to the points on the surface profile of the deformable mirrors (DMs). Off-axis three-mirror anastigmats are used to demonstrate the benefits of optical image stabilization with one- and two-deformable mirrors.
枸 杞 呼 吸 特 性 研 究  [PDF]
冯 美,张 宁
北方园艺 , 2010, DOI: 10.11937/bfyy.201019074
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