Image Segmentation of Brain MR Images Using Otsu’s Based Hybrid WCMFO Algorithm

In this study,a novel hybrid Water Cycle Moth-Flame Optimization(WCMFO)algorithm is proposed for multilevel thresholding brain image segmentation in Magnetic Resonance(MR)image slices.WCMFO constitutes a hybrid between the two techniques,comprising the water cycle and moth-flame optimization algorithms.The optimal thresholds are obtained by maximizing the between class variance(Otsu’s function)of the image.To test the performance of threshold searching process,the proposed algorithm has been evaluated on standard benchmark of ten axial T2-weighted brain MR images for image segmentation.The experimental outcomes infer that it produces better optimal threshold values at a greater and quicker convergence rate.In contrast to other state-of-the-art methods,namely Adaptive Wind Driven Optimization(AWDO),Adaptive Bacterial Foraging(ABF)and Particle Swarm Optimization(PSO),the proposed algorithm has been found to be better at producing the best objective function,Peak Signal-to-Noise Ratio(PSNR),Standard Deviation(STD)and lower computational time values.Further,it was observed thatthe segmented image gives greater detail when the threshold level increases.Moreover,the statistical test result confirms that the best and mean values are almost zero and the average difference between best and mean value 1.86 is obtained through the 30 executions of the proposed algorithm.Thus,these images will lead to better segments of gray,white and cerebrospinal fluid that enable better clinical choices and diagnoses using a proposed algorithm.

A Novel Segment White Matter Hyperintensities Approach for Detecting Alzheimer

Segmentation has been an effective step that needs to be done before the classification or detection of an anomaly like Alzheimer’s on a brain scan.Segmentation helps detect pixels of the same intensity or volume and group them together as one class or region,where in that particular region of interest(ROI)can be concentrated on,rather than focusing on the entire image.In this paper White Matter Hyperintensities(WMH)is taken as a strong biomarker that supports and determines the presence of Alzheimer’s.As thefirst step a proper segmentation of the lesions has to be carried out.As pointed out in various other research papers,when the WMH area is very small or in places like the Septum Pellucidum the detection of the lesion is hard tofind.To overcome such problem areas a very optimized and accurate Threshold would be required to have a precise segmentation to detect the area of localization.This would help in proper detection and classification of the Anomaly.In this paper an elaborate comparison of various thresholding techniques has been done for segmentation.A novel idea for detection of Alzheimer’s has been presented in this paper,which encompasses the effectiveness of an optimized and adaptive technique.The Unet architecture has been taken as the baseline model with an adaptive kernel model embedded within the architecture.Various state-of-the-art technologies have been used with the dataset and a comparative study has been presented with the current architecture used in the paper.The lesion segmentation in narrow areas has accurately been detected compared to the other models and the number of false positives has been reduced to a great extent.

LSFP下的机器人视觉定位技术研究

针对当前点云的定位算法中,多平面分割效果差、误匹配以及定位精度不够高等问题,提出LSFP的定位思想和C-S分割算法,对目标物体进行定位。在深度相机场景下,利用点云处理算法初步获取目标的位姿,经手眼标定后,进行初步引导;再使用3D扫描仪进一步定位目标物体。结果表明:(1)C-S分割算法对多平面分割效果良好,能更准确地去除多余平面,减少点云数量。(2)在垂直于Z轴且Z轴坐标值为171 mm和-10 mm的平面上,仅PrimeSense的定位距离的均方根误差为7.3 mm和8.2 mm,LSFP下的定位距离的均方根误差为2.6 mm和3.2 mm。(3)LSFP定位思想能扩大场景定位的范围,提高物体的定位精度,具有良好的准确性。

广义S变换和阈值分割联合抗频谱扩展-压缩移频干扰

根据频谱扩展-压缩(spectrum spread and compression,SSC)移频干扰信号和回波信号时频分布特性的差异,提出一种基于广义S变换和Tsallis交叉熵阈值分割的干扰抑制方法。分析了SSC移频干扰的干扰原理和干扰信号经过解线调后的信号形式,并利用时频聚焦性较好的广义S变换获取接收信号经过解线调后的时频图像,根据时频图像对应的灰度图像,以Tsallis交叉熵最小化作为目标函数,求出灰度图像的最佳分割阈值,并根据分割阈值构建时频滤波器,实现干扰抑制。仿真结果表明:该方法对于SSC移频干扰产生的假目标具有较好的抑制效果,干扰抑制比可达30 dB以上。

Study on the synthesis of spin labeled poly(styrene-co-maleic acid)s and their segmental motion

Study of the segmental mobility of polymer chains is important when the polymer is used as drag reduction agents of crude oil.Electron spin resonance(ESR)spectroscopy can provide important information about segmental dynamics of polymer chains,which is related to their microenvironment.In this article,we employed an amphiphilic polymer to study the effect of hydrophilic/hydrophobic balance of the polymers on the segmental motion of polymer chains.Poly(styrene-co-maleic acid)(PSMA)was spin labeled with 4-amino TEMPO radicals by increasing the concentration of radical moiety on the polymer chains.The PSMA and spin labeled-PSMAs(SL-PSMAs)were characterized by nuclear magnetic resonance(NMR),Fourier transform infrared(FT-IR)spectroscopy,Cyclic voltammetry(CV)and ESR techniques.Inter-polymer complexes(IPCs)of SL-PSMA-2 were prepared by employing polyethylene glycols(PEGs)of varying molecular weights.The results showed that the increased hydrophobic interactions of nitroxide radicals on the SLPSMAs’chains reduced the rotational mobility of spin labels and the random coil-toglobular transition of polymer chains occurred at higher pH value for SL-PSMAs,which showed a slow motion component in the ESR spectra of SL-PSMAs.Further,by increasing the molecular weight of PEGs in IPCs the complexation was increased,which also reduced the rotational motion of spin labels due to interpolymer hydrogen bonding causing a slow motion component in the ESR spectra.©2021 The Authors.

基于PSO-GRNN和D-S证据理论的电网分区故障诊断

针对大电网中保护和断路器误动、拒动、信息丢失等不确定的电网故障信息以及现有电网分区方法的不足,提出了基于粒子群优化广义回归神经网络(PSO-GRNN)和D-S证据理论的电网分区故障诊断方法。首先,通过改进图形分割法将大电网划分为相互重叠的不同区域,降低故障诊断难度。然后在各个区域建立PSOGRNN诊断模块,根据故障警报信息,并行完成各自的故障诊断任务。最后,采用D-S证据理论对相邻区域的重叠区域进行分析,以实现对重叠区域的综合故障诊断。仿真结果表明,该方法能有效识别非重叠区域和重叠区域的故障,容错能力强,诊断准确率高。

Modeling protein-protein interactions in axon initial segment to understand their potential impact on action potential initiation

The axon initial segment(AIS)region is crucial for action potential initiation due to the presence of high-density AIS protein voltage-gated sodium channels(Nav).Nav channels comprise several serine residues responsible for the recruitment of Nav channels into the structure of AIS through interactions with ankyrin-G(AnkG).In this study,a series of computational experiments are performed to understand the role of AIS proteins casein kinase 2 and AnkG on Nav channel recruitment into the AIS.The computational simulation results using Virtual cell software indicate that Nav channels with all serine sites available for phosphorylation bind to AnkG with strong affinity.At the low initial concentration of AnkG and casein kinase 2,the concentration of Nav channels reduces significantly,suggesting the importance of casein kinase 2 and AnkG in the recruitment of Nav channels.

Stepwise evaluation of liver sectors and liver segments by endoscopic ultrasound

The liver has eight segments, which are referred to by numbers or by names. The numbering of the segments is done in a counterclockwise manner with the liver being viewed from the inferior surface, starting from Segment Ⅰ(the caudate lobe). Standard anatomical description of the liver segments is available by computed tomographic scan and ultrasonography. Endoscopic ultrasound(EUS) has been used for a detailed imaging of many intra-abdominal organs and for the assessment of intra-abdominal vasculature. A stepwise evaluation of the liver segments by EUS has not been described. In this article, we have described a stepwise evaluation of the liver segments by EUS. This information can be useful for planning successful radical surgeries, preparing for biopsy, portal vein embolization, transjugular intrahepatic portosystemic shunt, tumour resection or partial hepatectomy, and for planning EUS guided diagnostic and therapeutic procedures.

基于对数-S型函数分段估计的快速去雾算法

针对雾霾天气下获取的图像细节丢失、颜色偏移、视觉质量退化等问题,提出一种基于对数-S型函数分段估计的大气光幕估计快速去雾算法。首先,在大气散射模型上深入推导,得到了大气光幕与有雾图像最小通道的正相关关系;然后,根据有雾图像不同区域具有不同的雾浓度,构造了分区域约束模型用以估计有雾图像的大气光幕;最后,提出基于中值滤波优化的中通道局部大气光估计方法,并结合大气散射模型恢复无雾图像。实验结果表明:所提算法复原图像的新增可见边、平均梯度,信息熵分别提升了17.4%、50.5%、30%,运行时间比传统快速去雾算法降低了17.5%。本文算法具有去雾彻底、颜色自然、细节明显的优点。

数控系统中S型曲线加减速控制算法研究

为了解决数控系统中S型加减速算法解析式方法缺乏的问题,提出一种7段式S型曲线加减速控制算法。该算法将所有7段式S型曲线可能出现的情况归纳为11个一元多次方程,再利用求根公式得到加减速时间。自主研发一种多轴运动控制卡,验证了7段式S型曲线加减速控制算法的所有情况。验证结果表明:该算法简单有效、运行稳定,能够满足高速高精度数控要求。

Optimization of Quantizer’s Segment Threshold Using Spline Approximations for Optimal Compressor Function

In this paper, the optimization of quantizer’s segment threshold is done. The quantizer is designed on the basis of approximative spline functions. Coefficients on which we form approximative spline functions are calculated by minimization mean square error (MSE). For coefficients determined in this way, spline functions by which optimal compressor function is approximated are obtained. For the quantizer designed on the basis of approximative spline functions, segment threshold is numerically determined depending on maximal value of the signal to quantization noise ratio (SQNR). Thus, quantizer with optimized segment threshold is achieved. It is shown that by quantizer model designed in this way and proposed in this paper, the SQNR that is very close to SQNR of nonlinear optimal companding quantizer is achieved.

基于D-S证据理论的指纹图像分割方法

在对D S证据理论进行简单分析之后 ,针对指纹图像提出了一种基于D S证据理论的图像分割算法 .该方法使用方向性和对比度两个信息分别作为两个分类器的特征 ,并利用模糊规则求出各分类器的基本概率分配函数 ,最后利用D S证据理论的合成法则将两个分类器的结果进行融合判决 .该方法具有较高的稳健性和精确度 。

汉坦病毒S基因的分段表达及其表达产物的鉴定

用含ＰＲＰＬ启动子的原核表达载体ＰＧＥＸ４Ｔ系统，构建了含汉坦病毒７６１１８株Ｓ基因全长片段（１．３ｋｂ）及部分片段（１．１ｋｂ和０．７ｋｂ）的表达载体ｐＧＥＸ４ＴＨａｎＳ，并在大肠杆菌中分别进行了表达。用１８株具有不同特异性的抗汉坦病毒ｍＡｂ，以ＥＬＩＳＡ夹心法对上述表达产物进行了检测。结果表明，重组基因全长片段的表达产物（ＮＰ）与其中１３株抗汉坦病毒组特异性和Ⅰ型特异性ＮＰ的ｍＡｂ均可发生反应；１．１ｋｂ基因片段的表达产物与上述ｍＡｂ都不起反应；０．７ｋｂ基因片段的表达产物只与上述部分ｍＡｂ发生反应。

S型铺管中上弯段管道受力研究

在使用S型铺管法铺设海底管道过程中,位于托管架上的管道(简称为上弯段)因受到较大的张力、弯矩及托管架的支撑反力作用,容易发生局部屈曲破坏。文中将托管架简化为连续型和滚轮支撑型两种,对连续型托管架上的管道进行了理论研究,并利用非线性有限元方法模拟了滚轮支撑作用下海底管道的受力状态。然后以12英寸管道为例,将两种托管架上的管道应变分布进行了对比。结果表明在连续型托管架上管道应变是一条直线;而滚轮支撑托管架上应变为波浪线,在滚轮作用处较大,滚轮之间较小。而且,应变随着张力的增大而增大,随托管架半径的增大而减小。

三维直方图重建和降维的Otsu阈值分割算法

针对三维Otsu阈值分割算法中因区域误分而产生的抗噪性差这一问题,提出了一种三维直方图重建和降维的Otsu阈值分割算法.该方法首先在详细分析三维直方图中噪声点分布的基础上,通过重建三维直方图,减弱了噪声干扰;然后将三维直方图区域划分由八分法改为二分法,使得阈值搜索的空间维度从三维降低到一维,减少了处理时间和存储空间.本文最后给出了算法的分割结果和运行时间,并与三维Otsu方法、二维分解法和二维斜分法进行对比.实验结果表明,本文算法的抗噪性更强,且分割效果更为理想,同时时间复杂度也远低于三维Otsu法.

Snake模型初始轮廓选取的研究

针对Snake模型处理复杂背景图像时的初始轮廓自动选取问题,该文采用分水岭算法先对图像进行分割,并将得到的边界作为Snake模型的初始边缘轮廓。由于分水岭算法具有将目标物体从复杂背景中分割开来的优点,使得在应用Snake模型对复杂图像进行分割时减少了人工的干预。经过实验对比,采用分水岭算法对玉米秸秆图像进行边缘轮廓的提取能达到较好的效果,为自动进行Snake模型的计算提供了一种较好的初始轮廓处理方法。

2型猪链球菌SspA基因序列及其免疫原性分析

【目的】明确2型猪链球菌的枯草杆菌素样丝氨酸蛋白酶(Ssp A)基因序列特征及其原核表达重组蛋白的免疫原性,为2型猪链球菌病的诊断及疫苗研究奠定基础。【方法】针对Ssp A基因上、下游序列分别设计1对引物,从112株2型猪链球菌临床分离株中扩增其相应片段,并进行测序分析;同时以Ssp A基因的重组质粒p ET28a-Ssp N、p ET28a-Ssp M和p ET28a-Ssp C分别转化感受态大肠杆菌BL21(DE3)后经IPTG诱导表达,再以SDS-PAGE检测融合蛋白表达情况,Western blotting鉴定其免疫原性。【结果】Ssp A基因上游片段较保守,而下游片段变异区间较大。在IPTG诱导下,含有重组质粒p ET28a-Ssp N、p ET28a-Ssp M和p ET28a-Ssp C的菌株表达出3段融合蛋白,其中,Ssp N和Ssp C重组蛋白存在于破碎菌体的上清液中,而Ssp M重组蛋白以包涵体形式存在于沉淀中,其大小为:Ssp N重组蛋白66 k D,Ssp M重组蛋白65 k D,Ssp C重组蛋白32 k D。Western blotting鉴定结果显示,3段重组蛋白均能与2型猪链球菌感染血清发生反应,且以Ssp N重组蛋白反应最强烈,而与以全菌灭活苗制备的猪血清未发生特异性反应。【结论】2型猪链球菌Ssp A基因上游片段较保守,经大肠杆菌重组表达的Ssp N蛋白免疫原性较强,且具备鉴别2型猪链球菌感染与免疫的潜力,可作为研究猪链球菌病血清学诊断的候选抗原片段。

江西省汉坦病毒分离及其S和M基因特征分析

目的对2011年江西省采集的鼠肺标本进行汉坦病毒的分离鉴定,了解分离病毒株的基因特征。方法采用Vero-E6细胞对阳性鼠肺标本进行病毒分离,采用直接免疫荧光法和RT-PCR方法对毒株进行鉴定。扩增分离株的S、M片段基因进行克隆测序。运用DNAstar软件包和MEGA3.1软件对序列进行分析。结果从15份标本分离到2株来自褐家鼠的汉城型汉坦病毒。对其中1株病毒的S、M片段进行了克隆和序列测定,其中S片段含1 772个核苷酸,编码429个氨基酸;M片段含3 651个核苷酸,编码1 133个氨基酸。经核苷酸和氨基酸同源性分析,新分离株与国内外汉城型病毒核苷酸同源性94.8%~98.0%,氨基酸同源性98.2%~99.6%。与汉城型标准株80-39株相比,S片段仅1个氨基酸位点发生变异;M片段有9个氨基酸位点发生变异,糖基化位点的数目和位置没有发生变化。结论从江西省褐家鼠分离到两株汉城型病毒,病毒基因变异较小,型别相对稳定。

基于分段改进S变换和随机森林的复合电能质量扰动识别方法

各类分布式设备和智能设备接入电力系统,使得电力系统对电能的波动越来越敏感,这导致对电能质量扰动(PQD)的识别和处理变得越来越重要。通过将分段改进S变换(SMST)和随机森林(RF)算法相结合,提出了一种用于复杂噪声环境下PQD识别的新方法。首先,基于检测误差和峰度对SMST的不同频段进行分别调参,并使用SMST提取待检测信号的75种时频特征,构成原始特征集。然后,改进分类回归树(CART)的节点分裂过程,加入了离散值处理策略并使用Gini指数的下降作为新的节点分裂规则。同时,在下次节点分裂前,将基尼指数下降值为零的特征从特征集中删除。最后,使用改进的CART算法构建了RF分类器并对复合PQD信号进行分类。实验证明,在不同的信噪比条件下,新方法均能有效识别多数单一PQD信号和常见的双重复合PQD信号。虽然新方法在运行效率方面仍有一定的改进空间,但其在不同层面上的改进均能有效提升PQD识别精度,且平均分类精度明显高于各类传统PQD识别方法。

一种结合二维Otsu法和模糊熵的图像分割方法

提出了一种结合二维Otsu法和模糊熵的图像分割方法,先采用二维Otsu法对图像进行初步分割,再采用模糊熵作后续处理,以弥补忽略边界信息带来的问题。实验结果表明,对于含噪图像,该方法的后处理效果是比较理想的。