Analysis of Fuzzy Arithmetic Method in Uncertain Parameters Problem

对标准模糊运算方法和最近提出的模糊算术转化方法进行了分析和比较,结合具体算例,说明了它们的优缺点和适用范围。标准模糊运算方法在进行模糊参数运算时存在严重缺陷,而转化方法具有较强的适应性,能够有效解决标准模糊运算方法存在的缺陷,是分析不确定参量系统的有效工具。The standard fuzzy arithmetic method and the transformation method proposed more recently for the analysis of systems with uncertain parameters are investigated.The advantages and drawbacks of the two methods are illustrated by some typical examples.It can be concluded that the transformation method is more effective and suitable for the investigation of systems with uncertain parameters.厦门大学信息985二期创新平台项目;; 福建省自然科学基金项目(D0310001)资

Algorithm for Network Delay Estimation Based on End-to-End Data Moment

现有时延层析算法大多考虑离散时延模式,但算法效率比较低。为此,提出一种连续时延估计算法,假定链路时延为某参数的函数分布,根据多播特征并基于端到端数据的矩,利用非线性最小二乘法估计链路时延分布函数的参数,并在每步迭代中用一维牛顿搜索确定最优步长,达到快速收敛。应用MATlAb和nS2仿真软件得到的数据表明,该算法所需的存储量少,算法简单且效率较高。The up-to-date algorithms on delay tomography are based on the discrete delay mode,but it is low efficiency in this mode.This paper proposes a continuous delay mode,whose delay is distributed on a function with some parameters.According to the rule of multicast and based on end-to-end moments,the parameters can be estimated using nonlinear least squares and the best step is chosen by the one-dimension Newton search in iteration.Experimental results on Matlab and NS2 simulation show that the algorithm needs little storage and is simple with high efficiency.国家自然科学基金资助项目(41074077;40774065

First Arrival Picking Based on Image Processing Methods

摘要:地震波初至时间的检测是地震信号处理中的一个重要环节。在地震波接收记录上 ,初至波振幅大于噪声振幅 ,初 至时间位于纯噪声信号与地震有效信号和噪声之叠加信号之间的分界处。根据这些特征 ,本文把地震信号幅值数据处 理成 256级灰度图 ,再把灰度图二值化 ,然后通过检测二值图像的边缘 ,获得地震波的初至时刻。对于存在较多的连续 异常记录道 ,或其它强干扰信号的地震波记录 ,提出了二次或多次用不同阈值对图像进行二值化的检测方法。对实际地 震记录的处理表明 ,本文方法具有较高的精度和效率。Abstract: This paper discusses a new method of first arrival p icking . The method is based on i mage p rocessingmethods . It is p ro2 posed for the purpose of aut omatic and accurate p icking of large v olumes of first arrival p icks for refracti on static analysis . The first step converts the seismic data int o a grey i mage . The second step converts the grey scale i mage t o a binary i mage . At last si mp le secondary p ick l ogic can be emp l oyed t o calculate a final p ick ti me . In the course of p icking, the paper discusses a new method t o influence the accuracy of p icking first arrival, converts the grey scale i mage t o more than 2 binary i mages by different threshold value . The experi mentati on has p r oven that the new method has great speed and efficiency .基金项目:福建省自然科学基金资助项目 (2006J0044) ;厦门大学 985二期信息创新平台项

POCT核酸检测试剂的冷冻干燥处理及其应用

目前应用于核酸现场检测的床旁检验(Point of care testing,POCT)产品均为通过将液态试剂脱水处理,让试剂以固态形式在室温下保存,使得试剂的保存运输不再受到低温的限制,其中,应用最广泛的脱水形式是冷冻干燥处理。冷冻干燥技术是使混合物中已经冻结的固态冰不经融化成液态水的过程而直接升华成气态,最终去除水分并保留其他有效组分的新式高效干燥技术。由于生物活性原料在固态干粉状态下的稳定性远高于液态,因此,通过冻干脱水处理,即能实现PCR体系中各组分在室温下的长期保存及稳定运输。该文综述了PCR扩增体系冻干试剂的制备工艺,包括冻干保护剂的添加与赋形剂的使用,并对核酸冻干试剂的应用前景进行了展望。国防科技创新特区专项(1716312ZT00501201);;国家科技重大专项(2017ZX10302101-001-002

Algorithm of Multicast Network Topology Inference Based on Packet Loss Rate

在分析现有的网络拓扑推断算法的基础上,提出一种改进的基于丢包率的多播网络拓扑推断算法。结合接收节点的层次信息、汉明距离及节点接收的探测包数量,能够同时推断网络拓扑结构和链路丢包率,并根据链路丢包率的估计值动态地调整拓扑推断的判决门限值,提高了推断的准确性。仿真实验证明,与现有算法相比,该算法具有更好的性能。By analyzing the existing network topology inference algorithms,this paper presents an improved multicast network topology inference algorithm based on packet loss rate.It combines the hop count of receivers,the Hamming distance and the number of received probes and can infer multicast network topology and loss performance simultaneously.It adapts dynamically the value of threshold according to the estimation of link packet loss rates,it improves the accuracy of the inference.Simulation results show that compared with the existing algorithms,this algorithm has better performance.福建省自然科学基金资助项目(2006J0044

Improvement of shortest path ray tracing method

综述了用网络最短路径算法求解地震射线追踪问题的原理、方法技术以及存在问题和改进措施 .特别介绍了作者在最短路径算法基础上 ,提出的动态网络最短路径地震射线追踪方法 .该方法先采集从炮点到整个模型所有节点上的初至旅行时 ,其中 ,在一个单元内 ,对相邻每对已计算出最小旅行时的节点进行线性插值 ,并利用Fermat原理计算未知节点的最小旅行时 ;然后 ,利用同样的方法 ,从接收点开始 ,反向追踪炮点到接收点的射线路径 .该方法能适于各种复杂的非均匀介质 ,极大地提高了射线追踪的精度 .The principle and method of seismic raytracing with shortest path algorithm in networks are discussed, the relevant drawbacks in which and improved measures are also analyzed. Especially, we develop a shortest path raytracing method with dynamic networks based on the shortest path algorithm. The wavefront times are sampled at the nodes away from the source throughout the entire model. The first arrival times at nodes in a cell are expressed with linear interpolation between traveltimes obtained aforehand at each pair of two neighboring nodes, and then determined by Fermat principle. After the first arrival times being sampled throughout the model, the raypaths from the source to each receiver are obtained backward away from the receiver to source in the same way as the forward sampling. This algorithm is regardless of model complexity, and has a higher precision for computation of seismic traveltimes and raypaths

A Parallel Algorithm for Fresnel Tomography

摘要:与射线层析成像相比, Fresnel 层析成像考虑波频率的影响, 具有较高的分辨率,但所需的存储 空间和计算量更大,因此提出了Fresnel 层析成像的并行算法1 把大型层析反演方程组的求解,转化成 对其中的各个方程进行相互独立的计算,避免了大型系数矩阵的存储问题;把一个Fresnel 带的正演和 反演计算放在一个进程,不同Fresnel 带的计算相互独立进行,不需要信息传递,达到了极高的并行度; 从进程之间没有通信, 仅当从进程计算结束后,在主进程与各从进程之间有少量的数据传递,使通信开 销达到了极小的程度1 应用MPI 在Linux PC 集群环境下实现了该算法,实际测试表明,该算法具有较 高的并行度和加速比.Abstract 　In cont rast with ray2based t raveltime tomography , Fresnel tomography account s for the band2 limited nature of seismic waves and gives the higher resolution tomograms1 Because Fresnel tomography demands much computer memory and much running time , a parallel algorithm for it is proposed1 The tomographic inversion is t ransformed to resolving respectively a series of single equation in light of backprojection principle , each equation corresponding to a Fresnel zone1 The forward and inverse computation concerning a Fresnel zone is allocated to one process and is independent of other processes1 Then the storage and calculation of the large2scale mat rix in the tomography are avoided1 No message delivers between the slave processes , and only a little of data delivers between a master process and the slave ones1 By using the portable message passing interface standard (MPI ) for the communication , the computing code of the algorithm is implemented on Linux system , which allows to dist ribute the work on several PCs connected via standard Ethernet in an in2house network , and greatly expands the applicability of Fresnel tomography1 The test s on the synthetic and observed seismic t ravel time data show that this parallel algorithm has a good performance on Linux PCs1基金项目:国家自然科学基金项目(40774065) ;福建省自然科学基金项目(2006J0044

Using of Wet Process to Remove of Heavy Metals from Waste Incineration Fly Ash

以福建和湖北垃圾焚烧发电厂采集的飞灰为研究对象,比较了单独水洗、水洗结合酸洗等工艺对飞灰重金属的洗脱效果,考察了不同酸洗工艺条件下飞灰重金属浸出毒性的变化。结果表明:在水灰比为10时水洗效果最佳,水洗结合酸洗处理可有效降低飞灰重金属浸出毒性,部分飞灰经湿法脱除后可作为普通废物排放。Taking the fly ash samples obtained from Fujian and Hubei waste incineration plants as the research subjects,the effects of water washing and wash+acid washing for heavy metal extraction from fly ash were compared.The changes of leachimg toxicity of heavy metals from fly ash were investigated under different acid washing conditions.The results showed that the effect of water washing was best when the ratio of water to fly ash was 10 ∶ 1(L/kg).Water+acid washing process can effectively reduce the leachimg toxicity of heavy metals.Part of fly ash can be disposed as ordinary waste after treated by wetextraction process

Dual-tree complex wavelet image denoising based on parental and neighboring coefficients

考虑二维双树复数小波变换(dTCWT)具有良好的平移不变性和方向选择性,基于当前系数与父系数及邻域系数间的关系,构造了dTCWT图像去噪阈值计算公式,提出了一种去噪方法,PndTCWT。该方法在对图像进行二维dTCWT变换后,利用阈值公式,根据当前系数和父系数及相邻系数计算收缩阈值,对当前系数进行去噪处理。最后,经过二维dTCWT反变换,得到去噪结果。实验结果表明,PndTCWT的噪声抑制效果明显优于各种基于dWT的去噪方法和其他dTCWT去噪方法。与基于父系数的dTCWT去噪方法相比,PndTCW的峰值信噪比(PSnr)平均提高了0.5 db左右。从视觉效果来看,PndTCW能在去噪的同时较好地保留图像细节,物体轮廓显得比较平滑,不存在传统dWT算法中的混淆现象。By considering the advantages of the 2D Dual Tree Complex Wavelet Transfer(DTCWT) in shift invariance and directionality,a threshold denoising formula based on parental and neighboring coefficients is constituted and a novel Parental and Neighboring DTCWT(PNDTCWT) image denoising method is presented.By proposed method,the shrinkage threshold of each coefficient is calculated to use in denoising for the current coefficient.After 2D DTCWT transfer to an original image, the final image is obtained by the inverse DTCWT of these denoised coefficients.Experimental results show that the denoising performance of the PNDTCWT is better than those of other denoising methods based on DWT or other DTCWT methods,and its Peak Signal Noise Ratios(PSNRs) have improves by 0.5 dB averagely as compared with that of parental coefficients based DTCWT denoising method.In terms of visual quality,PNDTCWT can get the images with more details,smooth profiles and without confusion effect.航空科学基金资助项目(No.05F07001);国家自然科学基金资助项目(No.60472081