Data classification from the inverse nth power gravitation

By the inverse nth power gravitation in physics,a novel classifier for data classification,called the I-n-PG classifier,is introduced.In the I-n-PG model,training samples from each class are regarded as a system of particles and an I-n-PG field is defined for each class.A test sample belongs to the class whose particle system has the maximum I-n-PG to this test sample.Experiments on large numbers of real data show that the I-n-PG classifier can provide a good classification performance.Compared with the nearest neighbor classifier and SVM,performances of the I-n-PG classifier are always superior/close to the better one of them,and thus the I-n-PG classifier has also a wide range of adaptability to data sets.     

An efficient rendering method for large vector data on large terrain models

This paper presents an efficient way to render large-scale vector maps on level-of-detail(LOD) digital elevation models(DEMs).By using the frame buffer and Voronoi diagram,we achieve a rapid simplification of large-scale vector maps while keeping their original topological relationships.With the simplified maps,we establish level-of-detail vector map models.In the detailed level,we use the stencil shadow volume approach to render the map accurately,and in the coarse level we use substitute techniques to ren...     

Thermal performance of solar air collector with transparent honeycomb made of glass tube

Transparent honeycomb structure with thin-walled glass tube as the honeycomb unit is designed and applied to a flat-plate solar air collector. Experiments are performed for solar collectors with six different honeycomb sizes. The emphasis is to study the effects of diameter and aspect ratio of the honeycomb unit on the transmittance and efficiency of the solar collector. It is shown that for the same diameter but different aspect ratios, there are large temperature differences between the collector’s exits;...     

HJ-1A/B卫星CCD影像大气订正

大气订正是遥感信息定量化研究中必不可少的一步,目前已有一些成熟的方法,但由于HJ-1A/B卫星CCD相机波段设置特点,常规的大气订正方法基本不适合于HJ-1A/BCCD影像.本文在大量分析HJ-1A/BCCD影像中不同地物的多种指数基础上,提出了改进暗目标法实现HJ-1A/BCCD影像的大气订正,该方法采用比值植被指数(RVI)、土壤调整植被指数(SAVI)和归一化水体指数(NDWI)的综合分析法确定暗像元自动提取,使之适用于环境减灾卫星CCD影像数据.为了客观地验证该方法的精度,本文选取地表平坦均一的敦煌校正场作为实验区,通过多次测量卫星过境时的地表反射率进行分析验证.     

Performance analysis of a noise-normalized FFH/MFSK receiver over Rayleigh fading channels with partial-band noise jamming

Fast frequency hopping can reduce the degradation caused by interference.The performance of noise-normalized fast frequency-hopped M-ary orthogonal frequency-shift-keying(FFH/MFSK)receivers over frequency nonselective Rayleigh fading channels with partial-band noise jamming is analyzed.Instead of numerical evaluation,a closed-form error probability expression is given based on the theory of complex variables. The simulation results validate the analytical results.It is shown that there is an optimum diversi...     

Controllability of Boolean control networks avoiding states set

In this paper, using semi-tensor product and the vector form of Boolean logical variables, the Boolean control network （BCN） is expressed as a bilinear discrete time system about state and control variables. Based on the algebraic form, the reachability and controllability avoiding undesirable states set are discussed. The reachability and controllability discussed here are under certain constraint and tile definitions of reachability and controllability avoiding undesirable states set have practical meaning. Also, the necessary and sufficient conditions for reachability and controllability are given. At last, the control sequence that steers one state to another is constructed.     

IDDT: Fundamentals and Test Generation

It is the time to explore the fundamentals of IDDT testing when extensive work has been done for IDDT testing since it was proposed.This paper precisely defines the concept of average transient current(IDDT) of CMOS digital ICs,and experimentally analyzes the feasibility of IDDT test generation at gate level.Based on the SPICE simulation results,the paper suggests a formula to calculate IDDT by means of counting only logical up-transitions,which enables IDDT test generation at logic level.The Bayesian optimization algorithm is utilized for IDDT test generation.Experimental results show that about 25% stuck-open faults are with IDDT testability larger than 2.5,and likely to be IDDT testable.It is also found that most IDDT testable faults are located near the primary inputs of a circuit under test.IDDT test generation does not require fault sensitization procedure compared with stuck-at fault test generation.Furthermore,some redundant stuck-at faults can be detected by using IDDT testing.     

城市基础地理数据整合与建库技术方案研究

以福州市基础地理数据整合与建库为例,阐述利用先进的管理理念和技术手段,解决城市基础地理数据因部门、行业分割造成的低水平重复建设、管理分散、共享困难等问题;通过数据整合试验,探讨城市基础地理数据整合与建库的技术方法,介绍了GIS技术、数据库技术、网络技术在实现城市基础地理数据整合与建库中的应用。     

应用有限元方法研究铁路车辆/轨道耦合系统在竖向冲击载荷作用下的动态响应

利用有限元方法研究铁路车辆/轨道动态耦合系统问题,得到车轮和轨道之间的竖向动态接触力与静载之间的关系.作为应用实例,对我国C61型运煤货车,考虑车辆/轨道系统各结构的真实几何形状和边界条件,建立包括车辆和轨道系统的有限元模型,应用大型非线性动力分析程序LS-DYNA模拟车辆通过轨道错牙接头时的轮/轨动态响应过程.通过分析发现,车轮和轨道之间的竖向动态接触力大约是静轮载的2倍,与已有的现场试验结果基本吻合.验证车辆/轨道系统有限元模型的正确性.进一步得到侧向架、钢轨和轨枕的加速度响应,以及轮轨接触区内的弹性应力场.