一种基于人工免疫的图像分割算法

图像二维熵分割,一直因耗时长而限制了实际应用。本文借鉴生物免疫思想,提出二维熵图像分割的人工免疫算法。在克隆选择算法中引入疫苗的免疫接种,用于优化最优分割阈值对的搜索过程。在遥感高分辨率图像上的实验显示,该算法不仅能准确搜索到最优阈值对,而且计算时间只有传统算法的1.8%。该算法也验证了人工免疫思想用于图像分割的可行性和有效性。     

一定分布模式下的最优Lp估计

观测数据在一定的分布模式下,需从理论上解决究竟用多大的ｐ值进行Ｌｐ估计（最优ｐ值的确定）,本文基于渐近方差整体最小的原则,给出了最优Ｌｐ估计的定义。观测数据中含有粗差（异常值）的扰动,其误差分布可视为污染分布,作者分析了最优ｐ值的大小,结果表明,若观测数据中含有不同大小、数量的粗差,为使Ｌｐ估计差最小,则ｐ将取［１．２,１．５］中的某一定值,Ｌｐ估计结果最优,此结论对测量数据处理具有一定的参考价值     

机车车辆滚动振动试验台的精密测量

本文针对国家重点牵引力动力实验室的机车车辆整车滚动振动试验台的特点，探讨了一套适合试验台安装和养护的精密测量方法，实践证明，这套方法能满足试验台安装所需的精度要求。     

测绘科技发展的现状、趋势及思考

科学技术的发展,使测绘学的内涵发生了深刻的变化。要立足本省发展测缥,必须抓住机遇,扩大宣传,加速发展;同时要加速各项基础设施的建设,开拓市场;积极养素质的人才,以适应现代测 产业的需要。     

Analysis of geometry-free residuals in case of traveling ionosphere disturbances and their impact cycle slip detection

GPS Solutions - We discuss the impact of a traveling ionospheric disturbance (TID) on cycle slip detection for the geometry-free (GF) combination. Based on the GF combination algorithm, we deduce...     

云南省出口东盟的特征及其经济和就业贡献率分析

利用海关信息数据、统计年鉴数据、相关贸易指标以及投入产出方法分析云南省与东盟之间的出口贸易特征,出口带来的经济和就业贡献。结果表明：云南省与东盟之间的贸易依赖关系显著增强,但是与东盟联系强度的空间分布不均匀,同时云南对东盟的出口产品出现升级特征,由矿产品、化工产品为主的出口转向了以农产品、电子制造产品为主的出口。云南省出口东盟农林牧渔产品对本省经济和就业贡献率最大,对农林牧渔产品深加工,有助于云南省的经济增长和保障就业,同时也有助于促进产业发展向技术密集型产业转型。     

Main genetic types of Ni ore deposits in China and their relations to paleo-plate tectonics

So far three main genetic types of nickel deposit have been recognized in China: magmatic copper-nickel sulfide deposits, nickel deposits occurring in the crust of weathering, and sedimentary nickel deposits. On the basis of the geotectonic settings of intrusive bodies, their genetic types, and the way sulfides are concentrated, the copper-nickel sulfide deposits fall into two broad categories: deposits emplaced along paleolandmass edges and those in the mobile zones on the outside of paleolandmasses. They can further be divided into six sub-categories and then a variety of types. The magmatic copper-nickel sulfide deposits constitute one of the most important genetic types in China. Geological evidence shows that the individual ferruginous ultrabasic bodies intruding along paleolandmass edges are most favourable for Ni-mineralization. In the light of the paleo-structural analysis, the author has proposed three mechanisms with respect to the formation of Ni-bearing ultrabasic bodies.     

Initial results of centralized autonomous orbit determination of the new-generation BDS satellites with inter-satellite link measurements

Autonomous orbit determination is the ability of navigation satellites to estimate the orbit parameters on-board using inter-satellite link (ISL) measurements. This study mainly focuses on data processing of the ISL measurements as a new measurement type and its application on the centralized autonomous orbit determination of the new-generation Beidou navigation satellite system satellites for the first time. The ISL measurements are dual one-way measurements that follow a time division multiple access (TDMA) structure. The ranging error of the ISL measurements is less than 0.25 ns. This paper proposes a derivation approach to the satellite clock offsets and the geometric distances from TDMA dual one-way measurements without a loss of accuracy. The derived clock offsets are used for time synchronization, and the derived geometry distances are used for autonomous orbit determination. The clock offsets from the ISL measurements are consistent with the L-band two-way satellite, and time–frequency transfer clock measurements and the detrended residuals vary within 0.5 ns. The centralized autonomous orbit determination is conducted in a batch mode on a ground-capable server for the feasibility study. Constant hardware delays are present in the geometric distances and become the largest source of error in the autonomous orbit determination. Therefore, the hardware delays are estimated simultaneously with the satellite orbits. To avoid uncertainties in the constellation orientation, a ground anchor station that “observes” the satellites with on-board ISL payloads is introduced into the orbit determination. The root-mean-square values of orbit determination residuals are within 10.0 cm, and the standard deviation of the estimated ISL hardware delays is within 0.2 ns. The accuracy of the autonomous orbits is evaluated by analysis of overlap comparison and the satellite laser ranging (SLR) residuals and is compared with the accuracy of the L-band orbits. The results indicate that the radial overlap differences between the autonomous orbits are less than 15.0 cm for the inclined geosynchronous orbit (IGSO) satellites and less than 10.0 cm for the MEO satellites. The SLR residuals are approximately 15.0 cm for the IGSO satellites and approximately 10.0 cm for the MEO satellites, representing an improvement over the L-band orbits.     

The Austrian node of the natural resources satellite remote sensing cloud service platform:examples of Sino-Austrian cooperation

The Austrian node of the Natural Resources Satellite Remote Sensing Cloud Service Platform was established in 2016 through a cooperation agreement between the Land Satellite Remote Sensing Application Center(LASAC),Ministry of Natural Resources of the Peoples Republic of China and the University of Vienna,Austria.Under this agreement panchromatic and multi-spectral data of the Chinese ZY-3 satellite are pushed to the server at the University of Vienna for use in education and research.So far,nearly 500 GB of data have been uploaded to the server.This technical note briefly introduces the ZY-3 system and illustrates the implementation of the agreement by the first China-Sat Workshop and several case studies.Some of them are already completed,others are still ongoing.They include a geometric accuracy validation of ZY-3 data,an animated visualization of image quick views on a spherical display to demonstrate the time series of the image coverage for Austria and Laos,and the use of ZY-3 data to study the spread of bark beetle in the province of Lower Austria.An accuracy study of DTMs from ZY-3 stereo data,as well as a land cover analysis and comparison of Austria with ZY-3 and other sensors are still ongoing.     

奉献农业 发展学科——对黄秉维院士农业研究工作的认识

简述了黄秉维院士的农业研究工作的光辉历程,分析了黄秉维农业研究工作的特色,强调学习黄秉维的精神.