激光变长线快速成型系统中的图形分区算法

在建立激光变长线快速成型系统加工过程的数学模型的基础上 ,提出了一种可对任意平面图形进行分区处理的分区算法 .该算法的使用不仅使所得分区图形能满足激光变长线扫描的要求 ,还可以使平面图形的分区数最少 。

运用标准误差法识别泵功图中游动阀的开闭点

针对现有的功图中游动阀开闭点识别技术存在的不足,提出了一种新的识别方法。该方法给出了一种新的泵功图分区方法,缩小了游动阀开、闭点的寻找范围;建立了中值去噪模型和平滑去噪模型,有效地消除了噪声的影响;首次提出了基于标准误差法(SE)的游动阀开、闭点计算模型,利用同类数据间变化量小而类与类之间数据变化量大的数据结构特性和标准误差法的统计特性,达到了准确提取泵功图中游动阀开、闭点位置的效果。实例验证结果表明:该方法不仅可准确提取泵功图中游动阀开、闭点的位置,而且其提取精度较之曲率法识别算法和斜率法识别算法有较大的提升。

图形激光标刻中的分区遗传算法

针对目前激光标刻系统中最短路径算法生成时间长、路径效果达不到最优的特点,提出了一种全新模式最短路径算法。首先根据图形平面分布特点,将分布位置接近的图形集中到一个区域,使所有图形划分到多个区域;其次对各个区域内图形进行路径优化,这样可以减少算法优化规模,提高算法效率;然后采取最优方式对各区域排列顺序进行调整,要求各区域内之间的总体距离最短;最后所有图形根据调整后的排列顺序依次输出,得到优化路径。实验结果证明,相比原有算法,本文算法在生成时间上提升近97%,路径效果提升近5%,在算法生成时间和路径效果上具有明显优势,更适合应用于激光标刻系统。

Efficient volume preserving approach for skeleton-based implicit surfaces

This paper presents an efficient way to preserve the volume of implicit surfaces generated by skeletons. Recursive subdivision is used to efficiently calculate the volume. The criterion for subdivision is obtained by using the property of density functions and treating different types of skeletons respectively to get accurate minimum and maximum distances from a cube to a skeleton. Compared with the criterion generated by other ways such as using traditional Interval Analysis, Affine Arithmetic, or Lipschitz condition, our approach is much better both in speed and accuracy.

Pest Detection Method Using Multi-Fractal Analysis

A novel method for pest detection is proposed based on the theory of multi-fractal spectrum to extract pests on plant leaves.Both local and global information of the image regularity were obtained by multi-fractal analysis.By applying fractal dimension,the spots on leaf images can be extracted without loosing or introducing any information.The different parts of images are re-analysis by morphology operations to determine the candidate regions of pests.The performance of multi-fractal analysis of whitefly detection is investigated through greenhouse experiments.The experimental results show that the proposed method is robust to noise from light and is not sensitive to the complex environment.

Geographical Space Development Zone Classification:An Essential Guide for Transformation of Mountain Resource Cities

Sustainable development of mountain areas and resource cities has been a significant issue worldwide. Transformation of mountain resource cities is facing tremendous difficulties. In the context of National Major Function-oriented Zone Planning raised to a national strategic level in China, it is important to effectively implement the planning by studying geographical space development zone classification of prefecture- and county-level cities based on their major function orientation. This research is even more critical for the transformation of mountain resource cities. In this study, we evaluated geographical space development suitability, and classified geographical space development zones for Dongchuan Distric in Kunming City of Yunan Province, China, a typical mountain resource city. A quantitative grid-based evaluation was conducted using key-factor identification and restrictive-supportive comprehensive index determinati based on a geographic information system framework with different source data. The results included a classification of geographical space of Dongchuan into five types: the prohibited development zone, the inappropriate development zone, the controlled development zone, the moderate development zone and the preferential development zone. The distribution characteristics of geographical space development zones showed that the proportion of the prohibited development zone is the highest, while that of the other four development zones is comparatively lower and significantly fragmented. The geographical space development suitability is greatly controlled by the geomorphic pattern. Although Dongchuan is extremely restrained in terms of suitable geographical space for industrialization and urbanization, it still has the certain preferential and moderate development zones with an area of 207.81 km2 with large parts being concentrated and contiguous, which makes these areas the most favorable for development. Only by adapting to this reality and implementing centralized development strategy in the regions with higher suitability may Dongchuan achieve smooth transformation from expansion mode to compact mode and its sustainable development capacity may be improved. Suggestions with an angle of industrial and spatial development pattern were put forward for the transformation of the city in future.

直接比对法等高线查错方法与程序研究

本文通过分析高程点、高程注记与等高线的关系,论证了该方法的可行性,并特别针对可能导致查错偏差的特征线和特征面以及微型地貌给出了检测和处理的方法,叙述了本方法的具体实现步骤,并通过实例说明了本方法的实际应用效果。

电子束光刻研制高分辨X射线波带片透镜最新进展

首先综述了当前X射线透镜的分辨率和效率的水平,预测并讨论了发展我国波带片透镜、赶超国际先进水平的技术路径图。在原有100 nm分辨率波带片和会聚透镜工艺基础上,综述了电子束光刻结合金电镀进一步发展30~70 nm分辨率的X射线波带片的最新进展。在研发30 nm分辨率的波带片中,电子束光刻中的邻近效应严重限制了波带高宽比,而现有商业软件(基于蒙特卡罗模型和显影动力学)的邻近效应修正在同时处理从微米到30 nm的各种图形时效果甚微。为此,本团队针对70 nm分辨率的硬X射线波带片采用了图形修正法,实现了20:1的波带高宽比,针对50 nm分辨率的硬X射线波带片采用了分区域修正法,获得了15:1的波带高宽比;30 nm波带片透镜的金属化摒弃了传统的直流电镀工艺,采用脉冲金电镀,实现了金环均匀电沉积,成功研制了30 nm分辨率的软X射线波带片透镜和30~100 nm的大高宽比分辨率测试卡。所有研制的波带片透镜在上海同步辐射装置得到了X射线光学成像验证。