Run_Length压缩算法的改进及C++的实现

针对传统的RunLength压缩算法在应对极端数据时所遇到的问题,提出了改进极端数据影响的措施,采取调整计数长度和调整传统RunLength算法的策略,不用特定字符作为压缩标志,而使用特殊字节位来用作压缩标志,并调整了区分计数字节和数据字节的方法.改进后的算法,大大提高了重复数据长度大于63和大于127的数据的压缩率,为RunLength算法有针对性应用提供了改进方案,同时,给出了RunLength压缩算法的C++程序代码.

New Algorithm for Binary Connected-Component Labeling Based on Run-Length Encoding and Union-Find Sets

Based on detailed analysis of advantages and disadvantages of the existing connected-component labeling （CCL） algorithm,a new algorithm for binary connected components labeling based on run-length encoding （RLE） and union-find sets has been put forward.The new algorithm uses RLE as the basic processing unit,converts the label merging of connected RLE into sets grouping in accordance with equivalence relation,and uses the union-find sets which is the realization method of sets grouping to solve the label merging of connected RLE.And the label merging procedure has been optimized：the union operation has been modified by adding the ＂weighted rule＂ to avoid getting a degenerated-tree,and the ＂path compression＂ has been adopted when implementing the find operation,then the time complexity of label merging is O（nα（n））.The experiments show that the new algorithm can label the connected components of any shapes very quickly and exactly,save more memory,and facilitate the subsequent image analysis.

Exact Run Length Evaluation on a Two-Sided Modified ExponentiallyWeighted Moving Average Chart for Monitoring

A modified exponentially weighted moving average (EWMA) scheme is one of the quality control charts suchthat this control chart can quickly detect a small shift. The average run length (ARL) is frequently used for theperformance evaluation on control charts. This paper proposes the explicit formula for evaluating the average runlength on a two-sided modified exponentially weighted moving average chart under the observations of a first-orderautoregressive process, referred to as AR(1) process, with an exponential white noise. The performance comparisonof the explicit formula and the numerical integral technique is carried out using the absolute relative change forchecking the correct formula and the CPU time for testing speed of calculation. The results show that the ARL ofthe explicit formula and the numerical integral equation method are hardly different, but this explicit formula ismuch faster for calculating the ARL and offered accurate values. Furthermore, the cumulative sum, the classicalEWMA and the modified EWMA control charts are compared and the results show that the latter is better for smalland intermediate shift sizes. In addition, the explicit formula is successfully applied to real-world data in the healthfield as COVID-19 data in Thailand and Singapore.

Trend Autoregressive Model Exact Run Length Evaluation on a Two-Sided Extended EWMA Chart

The Extended Exponentially Weighted Moving Average(extended EWMA)control chart is one of the control charts and can be used to quickly detect a small shift.The performance of control charts can be evaluated with the average run length(ARL).Due to the deriving explicit formulas for the ARL on a two-sided extended EWMA control chart for trend autoregressive or trend AR(p)model has not been reported previously.The aim of this study is to derive the explicit formulas for the ARL on a two-sided extended EWMA con-trol chart for the trend AR(p)model as well as the trend AR(1)and trend AR(2)models with exponential white noise.The analytical solution accuracy was obtained with the extended EWMA control chart and was compared to the numer-ical integral equation(NIE)method.The results show that the ARL obtained by the explicit formula and the NIE method is hardly different,but the explicit for-mula can help decrease the computational(CPU)time.Furthermore,this is also expanded to comparative performance with the Exponentially Weighted Moving Average(EWMA)control chart.The performance of the extended EWMA control chart is better than the EWMA control chart for all situations,both the trend AR(1)and trend AR(2)models.Finally,the analytical solution of ARL is applied to real-world data in the healthfield,such as COVID-19 data in the United Kingdom and Sweden,to demonstrate the efficacy of the proposed method.

Gender Classification Based on Multi-Scale and Run-Length Features

Human faces can convey substantial information about a person,such as his or her age,race,identity,gender,and emotions.Such facial information can be obtained through techniques like human facial tracking and detection,facial recognition,gender classification,emotion recognition,as well as age estimation.Of these,gender classification is particularly important due to its diverse applications in the fields such as video surveillance and commercial advertising.In this thesis,we propose a method of gender classification based on run-length histograms.The proposed method uses a run-length histogram to record the position information of pixels,thereby efficiently improves the recognition rate and makes the technique suitable for a big-data multimedia database.The experimental results show that the proposed method can achieve better accuracy than a multi-scale based method can.

A Dynamic Steganography Method for Web Images with Average Run- Length-Coding

Web page has many redundancies,especially the dynamic html multimedia object.This paper proposes a novel method to employ the commonly used image elements on web pages.Due to the various types of image format and complexity of image contents and their position information,secret message bits could be coded to embed in these complex redundancies.Together with a specific covering code called average run-length-coding,the embedding efficiency could be reduced to a low level and the resulting capacity outperforms traditional content-based image steganography,which modifies the image data itself and causes a real image quality degradation.Our experiment result demonstrates that the proposed method has limited processing latency and high embedding capacity.What’s more,this method has a low algorithm complexity and less image quality distortion compared with existing steganography methods.

Modified DS np Chart Using Generalized Multiple Dependent State Sampling under Time Truncated Life Test

This study presents the design of a modified attributed control chart based on a double sampling(DS)np chart applied in combination with generalized multiple dependent state(GMDS)sampling to monitor the mean life of the product based on the time truncated life test employing theWeibull distribution.The control chart developed supports the examination of the mean lifespan variation for a particular product in the process of manufacturing.Three control limit levels are used:the warning control limit,inner control limit,and outer control limit.Together,they enhance the capability for variation detection.A genetic algorithm can be used for optimization during the in-control process,whereby the optimal parameters can be established for the proposed control chart.The control chart performance is assessed using the average run length,while the influence of the model parameters upon the control chart solution is assessed via sensitivity analysis based on an orthogonal experimental design withmultiple linear regression.A comparative study was conducted based on the out-of-control average run length,in which the developed control chart offered greater sensitivity in the detection of process shifts while making use of smaller samples on average than is the case for existing control charts.Finally,to exhibit the utility of the developed control chart,this paper presents its application using simulated data with parameters drawn from the real set of data.

Footfall patterns of a runner with an Achilles tendon rupture

Purpose: This study aims to compare the load and the length of previously ruptured and healthy Achilles tendon(AT) of a recreational runner who used different footfall patterns on each limb during running.Methods: A 41-year-old recreational athlete with a ruptured AT participated in this report. Two force plates and a high-speed motion capture system were used to collect ground reaction force and kinematic data in shod and barefoot running conditions. AT length was measured using ultrasonography and an infrared camera system. AT force was estimated as the active plantar flexion moment divided by AT moment arm during stance phase.Results: The participant used a rearfoot pattern on the affected limb and a forefoot/midfoot pattern on the unaffected limb during shod running,and a forefoot/midfoot pattern during barefoot running. There was no difference between the length of the affected and the unaffected AT. During shod running, the maximal AT force and loading rate were lower in the affected AT versus the unaffected AT. During barefoot running, the affected maximal AT force and loading rate were greater than the unaffected AT.Conclusion: Footfall patterns can be an adaptation to reduce the loading on a previously injured AT. It appears that runners may consider using a rearfoot footfall pattern during running to reduce the stress on the AT.

非参数自适应EWMA SR控制图及其变采样间隔设计

本文基于Wilcoxon符号秩(Signed Rank, SR)检验统计量,提出了一种非参数自适应指数加权移动平均(Adaptive Exponentially Weighted Moving Average, AEWMA)控制图。所提出的AEWMA SR控制图结合了非参数统计量的稳健受控性能以及自适应控制图良好的整体偏移检测特性。同时,为了提高固定采样间隔下的非参数AEWMA SR静态控制图对异常偏移的检测效率,本文进一步研究了可变采样间隔(Variable Sampling Intervals, VSI)下的非参数AEWMA SR动态控制图设计问题。使用了Markov链方法计算控制图的精确平均运行链长(Average Run Length, ARL)和平均报警时间(Average Time to Signal, ATS)等性能指标。通过仿真分析比较了VSI AEWMA SR控制图、FSI AEWMA SR控制图和VSI EWMA SR控制图的统计性能。结果表明,所提出的VSI AEWMA SR控制图能兼顾对于不同大小偏移的敏感性,且变采样间隔的动态策略能显著提高控制图的检测效率。

基于正态变换的变样本容量Shewhart比例控制图设计

为了提高Shewhart型比例控制图的监控效率,将其与变样本容量策略结合,提出一种新的比例控制图(VSS Shewhart-RZ*控制图)来监控二元正态变量之比。基于正态变换方法设计了新的比例统计量Z*,以消除样本容量变化对比例控制图设计及使用的不利影响。采用马尔科夫链方法计算了该控制图的平均运行长度和平均样本容量,给出该控制图的参数优化算法。通过仿真分析研究了该控制图的统计性能,并与Shewhart比例控制图进行比较,结果表明VSS Shewhart-RZ*控制图的性能明显优于传统固定样本容量Shewhart比例控制图。

基于高光谱与纹理特征融合的甘草药材基源鉴别研究

不同甘草的基源鉴别对保障其临床应用具有重要意义。该研究基于乌拉尔甘草、胀果甘草和光果甘草3种基源共89根甘草药材的光谱特征,进一步利用灰度行程矩阵从4个角度(0°、45°、90°和135°)分别提取11个纹理特征参数(短行程强调、长行程强调、灰度不均匀性、行程不均匀性、行程百分比、低灰度行程强调、高灰度行程强调、短行程低灰度强调、短行程高灰度强调、长行程低灰度强调、长行程高灰度强调)对甘草药材进行鉴别,开发了归一化后求平均值的差异度法(NAD),筛选出对基源鉴别贡献较大的5个纹理特征,并将其与光谱特征进行融合,以提高基源鉴别的准确性。与传统的特征筛选方法SKB法、RFE法和SFM法相比,归一化后求平均值的差异度法展现出更高的适用性,支持向量机(SVM)分类器在测试集上的基源鉴别准确率达到了95.28%,高于未筛选(92.22%)、SKB法筛选(95.00%)、RFE法筛选(95.00%)和SFM法筛选(93.89%)的准确率。该研究提出的数据挖掘方法充分利用高光谱的光谱数据和图像数据,将光谱特征和纹理特征进行有机融合,为甘草药材的基源鉴别提供了一种新型无损的检测方法。

斜齿轮的有效长度和收尾长度的计算

文章基于理论分析并应用Lagrange乘数法以及求解一个一元四次方程,推导得到了与圆柱型齿条配合的斜齿轮所需要的有效长度的解析表达式,并通过SolidWorks软件验证了其正确性。再通过求解一元四次方程,推导得到了斜齿轮的滚齿收尾部分最远端到垂直于工件轴线且包含退刀时滚刀轴线和工件轴线的最短距离线所在平面的距离,即滚齿收尾长度的解析表达式,并通过SolidWorks软件验证了其正确性。这两个表达式为与斜齿轮相关的机械产品的设计提供了重要依据。

一种相邻游程增量编码的测试数据压缩方案

随着集成电路制造工艺的高速发展,其构造越来越复杂,测试成本也越来越高,而压缩测试数据是降低测试成本的有效方法之一。本文在双游程交替编码基础上,提出了一种相邻游程增量编码的测试数据压缩方案。先通过编码表获得当前游程编码长度N,然后得到当前游程减去前一游程的差值M,当M不为负数且比N-1小时,使用M+1个0表示当前游程。在压缩过程中,通过实时对比两种编码的长度,并选择长度小的编码以进一步压缩数据,实验证明本方案有着良好的压缩效果。

胎冠弧弦长与行驶面宽度之比对轮胎性能的影响

以11.00R20全钢子午线轮胎为对象,研究胎冠弧弦长与行驶面宽度之比对轮胎性能的影响。结果表明:胎冠弧弦长与行驶面宽度之比影响轮胎的接地印痕形状以及胎肩部位的剪应力最大值和应变能密度最大值,而对1#—3#带束层的剪应力最大值和应变能密度最大值影响不明显;胎冠弧弦长与行驶面宽度之比取55.5%~55.9%为宜。

基于游程编码的GIS栅格数据矢量化方法

为了克服传统栅格矢量化方法的各种局限性,提出利用栅格的游程编码和区位表在内存中直接进行栅格图形矢量化提取的有效方法,并描述了算法实现步骤。由于栅格游程编码具有提取方便、压缩比适中、和常规栅格之间的转换便捷等特征,所以本方法的采用使得在计算机内存中处理矢量化栅格的规模、精度、复杂程度和速度有较大提高,可广泛应用于栅格型地理空间分析和遥感图像专题要素类型的边界提取等方面,实践表明本文提出算法具有很高的效率,易于实现。

中国主要河流干旱特性的统计分析

在大量实测年径流量资料的基础上，分析了作为水文干旱定量指标负轮长的统计变化特性，并以哈尔滨和陕县站为例，以随机模拟途径探讨了严重干旱出现可能性的定量估计方法。结论是：Ｐ－Ⅲ型分布可用来表示负轮长的统计特性；平均负轮长和一阶自相关系数有密切的关系并具有一定的分区性；严重干旱出现可能性的定量估计，随机模拟途径最适当。

无边界游程编码及其矢栅直接相互转换算法

本文提出了无边界游程（ＮＢＲＬ）编码的栅格压缩格式及其与矢量格式之间直接相互转换的算法。无边界游程编码具有无矩形边框限制的特点，可随意扩展而无须改变整体参数，特别适合范围不同的两个栅格的各种组合运算。提出的提取多边形算法，可直接在游程上作标记，而不必先还原成非压缩格式，从而节省了内存，提高了速度。

实现栅格图形和图像数据矢量化提取的游程轮廓追踪法

提出一种直接利用栅格图形游程编码进行图斑边界多边形矢量化提取的有效方法。对遥感图像专题信息和栅格型地理空间分析结果的矢量化提取是GIS的重要手段 ,栅格数据结构可简化解决叠置分析等一类空间分析问题 ,其中需要高效矢量化技术的支撑。本方法充分利用栅格游程编码所具有的可操作性强、检索和转换便捷、隐含横向差异信息、可处理高精度和大规格图形和图像等特征 ,定义了“上邻游程”和“下邻游程” ,并采用相应有效查找算法和基于游程轮廓追踪的矢量化技术 ,使得计算机处理栅格数据矢量化的规模、精度和效率明显提高 ,可广泛应用于栅格型地理空间分析和遥感图像处理等方面。

改进游程编码在天气雷达数据压缩中的应用

为了有效地传输和存储海量遥感数据,必须研究符合遥感应用的压缩技术。通过研究传统的熵编码方法,结合雷达体扫数据的相关性,提出了一种基于改进游程编码的综合无失真压缩算法,应用于天气雷达原始数据压缩。实验结果表明,所给算法优于传统算法及目前流行的压缩软件。

应用混合游程编码的SOC测试数据压缩方法

本文提出了一种有效的基于游程编码的测试数据压缩/解压缩的算法:混合游程编码,它具有压缩率高和相应解码电路硬件开销小的突出特点.另外,由于编码算法的压缩率和测试数据中不确定位的填充策略有很大的关系,所以为了进一步提高测试压缩编码效率,本文还提出一种不确定位的迭代排序填充算法.理论分析和对部分IS-CAS 89 benchmark电路的实验结果证明了混合游程编码和迭代排序填充算法的有效性.