基于内容的图像检索技术研究

随着多媒体技术和网络技术的迅速发展,基于内容的图像检索已成为一个研究热点。文章首先概括介绍了基于内容图像检索的产生、发展,然后介绍了特征提取及其相似性度量、相关反馈等技术,最后对基于内容的图像检索发展方向进行了分析。     

Theoretical and experimental study on fiber Bragg grating sensing of rock strata settlement deformation

Based on the theory of fiber Bragg grating sensing, and using a 2 m plane stress material model of the simulation experiment, the wavelength shift regulations of fiber Bragg gratings under rock settlement deformation conditions were got, which provided reliable basis for the design of the wavelength bandwidth of sensing gratings. The wavelength increase when the rock layers are under tension, and decrease under compression. Compressive strain sensitivity is bigger than tensile strain sensitivity when the load is lower. However compressive strain sensitivity is smaller than tensile strain sensitivity when the load is higher. Experimental result coincides well with theory. The wavelength bandwidth of two neighboring fiber Bragg gratings of the gratings used for monitoring the deformation of rock layer should be no less than 6 nm. An effective new approach for detecting the deformation of rock settlement with fiber Bragg gratings is provided. Supported by the National Natural Science Foundation of China(50775060)     

济三矿风井厚松散层沉降变形光纤光栅监测方法

为了准确预测深厚松散层深部层位因失水压缩变形,分析总结了松散层不同深度黏土层和砂层的失水特征、压缩变形特性,采用松散层钻孔植入式光纤光栅监测系统,对济三矿风井处第四系松散地层104—180 m段埋设的18个光纤光栅传感器进行了长期的实时监测,由光栅传感器监测的松散层应变得出了各层位的压缩变形量。监测结果表明,松散层下组的厚砂砾层是产生主要压缩变形层,可塑状态的厚黏土层也有较大压缩变形,其余层位压缩变形小。下组厚砂砾层和厚黏土层是重点监测层位,为深钻孔植入式光纤光栅监测系统监测设计提供了依据。     

一种基于Web的HTML到XML数据转换方法

随着Internet的发展,以HTML格式显示的Web数据越来越不适应新的发展需求,而用来描述和存储数据的XML语言有着许多优于HTML的技术,于是将HTML格式的数据用XML格式表示出来,是现在网络应用中需要解决的问题。这里介绍的基于Web的HTML到XML数据转换方法能够有效地把HTML格式的文件转换成XML（XHTML）格式的文件。     

基于光纤光栅监测的松散地层深部注水试验

为了探索厚松散地层深部失水层位的钻孔注水特性，采用一种新型的光纤光栅传感系统实现了某矿松散层注水过程中应变的在线监测。介绍了在深度+115.83～+135.15 m处松散层注水实施过程，及通过2个钻孔对注水层位应变和水位监测的光纤Bragg光栅系统及水位监测系统，注水试验注水压力值依次为0.1，0.2，0.3 MPa和总注水量达到4 226.84 m 3。分析了注水压力、注水量和松散层应变变化的关系，松散层在注水前后和过程中松散层应力应变状态。试验表明，随着注水压力升高和注水量增加，松散层压缩状态得到改善，较注水前，注水后注水层位呈明显拉伸状态。光纤光栅监测系统灵敏、稳定，能够实现对松散层深部注水的过程实时监测，试验为进一步实施松散层地区沉降治理提供了重要的依据。     

Study on rock deformation monitoring using fiber Bragg grating in simulation experiment

Presented the fiber Bragg grating （FBG） sensors for rock strain monitoring in the 1.2 m long plane stress model of the simulation experiment. In the past, for the lack of appropriate technique to measure the deformation of rock structures, the measurement of deflection was restricted to just a few discrete points along rock, and the measuring points were limited to the location installed with displacement transducers. We developed a method to monitor the deformation of rock structures using fiber optical Bragg grating strain sensors. The sensors were embedded in rock layers of simulation experiment before the materials were put in. These sensors were then used to monitor the experienced strain with different face advancing distance. The test results indicate that, if properly installed, FBG sensors can survive under severe conditions associated with embedment process and yield accurate measurements of strains response. At the same time, we make comparisons of the data obtained by FBG sensors with those by centesimal gauge. The interest in FBG sensors was motivated by the potential advantages that they can offer more than existing sensing technologies.