Editing Vector Graphics in the Virtual Simulation Environment

We present a method to represent multi-resolution vector graphics such as road networks or railway networks in virtual environment. These vector data can be interactively edited and the landscape and be explored in real time at any altitude from flight view to car view. We design a context-focused vector description of linear can areal features, with associated customized definition painter to specify their appearance （color and material） and their display mode （detailed mode or simplified mode）. There are some special problems in drawing vector graphics in virtual environment. Floating-point round-off error appear when we use a low view point to observe the scene, and it leads to scene jittering. Drawing 3D wide lines turns into a problem on 3D terrain. We design a view-based self-adaptive interpolation algorithm and an offset line generating algorithm to solve it. Our results show high performance with good visual quality.

A visualized presentation method of Muqam music inheritance regions based on SVG

Sinkiang Muqam music, which is a combination of song, dance, music, folk-custom and literature, is in the list of World Intangible Cultural Heritage. It is distributed in different regions in Sinkiang. Because of the different inheritance regions as well as the different inttuence of history and culture, there formed Muqam music of different region style, further presented different artistic style. This article presents a method to intuitively show the inheritance distribution of tour kinds of Muqam music in Sinkiang based on scalable vector graphics technology, it provides methods and tools of visualization research on the protection and inheritance of Muqam music.

Implementation of paper-cut interactively display system based on AR

Paper-cut is one of the oldest folk arts of Han nationality, to give people visual space through feeling and artistic enjoyment. With the development of modernization, the number of person who inherits or understands the intangible cultural heritage is dwindling. Hence, we need a new form to inheritance this art urgently. Based on augmented reality technology, we achieve the real-time calculation of image position and angle, the exhibition of the corresponding virtual scene in this paper. Users can achieve the virtual interaction in reality, thus, multi-dimensional experience of paper-cut is provided for users.

A New Robust Watermarking Algorithm for Vector Data

Because the existing vector data watermarking algorithm is insufficiently robust for compression and cropping,and has no sufficient control on map deformation,a new watermarking algorithm was proposed in this paper.Its main features are：① it selected feature points and non-feature points from the sequence of Douglas,and then embedded watermarking points by wavelet transform,which is based on layer segmentation;② it enhanced the map deformation control design.Furthermore,it increased the map graphic deformation control design.The algorithm was applied to experimental data,and the test results showed that the algorithm had good robustness on graphics geometric transformation,the addition,deletion and cropping of points in graph layers.Also,the graph distortion had been well controlled.

CorelDRAW矢量地图高保真Web发布方法研究

基于CorelDRAW矢量地图产品,提出一种基于分层可缩放矢量图形(scalable vector graphics,SVG)组织、集成表达的技术方法,解决了高保真地图发布的问题。首先将CorelDRAW矢量地图高保真分层转换为多个SVG格式文件;然后对SVG文件中符号化信息进行批量处理;最后使用WebGIS框架库将各SVG地图加载到Web平台,实现CorelDRAW矢量地图的展示与交互。实验结果表明,该方法能将CorelDRAW矢量地图高效、高质量地发布到Web平台。

Why are Nitrogen Concentrations in Plant Tissues Lower under Elevated CO_2? A Critical Examination of the Hypotheses

Plants grown under elevated atmospheric [CO2] typically have decreased tissue concentrations of N compared with plants grown under current ambient [CO2]. The physiological mechanisms responsible for this phenomenon have not been definitely established, although a considerable number of hypotheses have been advanced to account for it. In this review we discuss and critically evaluate these hypotheses. One contributing factor to the decreases in tissue N concentrations clearly is dilution of N by increased photosynthetic assimilation of C. In addition, studies on intact plants show strong evidence for a general decrease in the specific uptake rates （uptake per unit mass or length of root） of N by roots under elevated CO2. This decreased root uptake appears likely to be the result both of decreased N demand by shoots and of decreased ability of the soil-root system to supply N. The best-supported mechanism for decreased N supply is a decrease in transpiration-driven mass flow of N in soils due to decreased stomatal conductance at elevated CO2, although some evidence suggests that altered root system architecture may also play a role. There is also limited evidence suggesting that under elevated CO2, plants may exhibit increased rates of N loss through volatilization and/or root exudation, further contributing to lowering tissue N concentrations.

Representation and Organization for Spatial Data in LBS

Aiming at the special demand on SVG_based representation and organization for spatial data in location based services（LBS）, the research is made in this article on the conversion method from multiple formats to SVG format, and a harris_corner detector method is proposed and verified to evaluate the conversion result. Based on the above, an optimized compression arithmetic is proposed, which integrated the characteristic of code simplification and GZIP compression. The test shows that the techniques on conversion and compression are feasible, which means that SVG_based representation is suited for spatial data in LBS and the improved compression arithmetic is prior to the former.