Effectiveness of inhibitors in increasing chloride threshold value for steel corrosion

This investigation was aimed at evaluating the effectiveness of corrosion inhibitors in increasing the chloride threshold value for steel corrosion. Three types of corrosion inhibitors, calcium nitrite （Ca（NO2）2）, zinc oxide （ZnO）, and N,N＇-dimethylaminoethanol （DMEA）, which respectively represented the anodic inhibitor, cathodic inhibitor, and mixed inhibitor, were chosen. The experiment was carried out in a saturated calcium hydroxide （Ca（OH）2） solution to simulate the electrolytic environment of concrete. The inhibitors were initially mixed at different levels, and then chloride ions were gradually added into the solution in several steps. The open-circuit potential （Ecorr） and corrosion current density （lcorr） determined by electrochemical impedance spectra （EIS） were used to identify the initiation of active corrosion, thereby determining the chloride threshold value. It was found that although all the inhibitors were effective in decreasing the corrosion rate of steel reinforcement, they had a marginal effect on increasing the chloride threshold value.

On Accelerated Singular Value Thresholding Algorithm for Matrix Completion

An accelerated singular value thresholding (SVT) algorithm was introduced for matrix completion in a recent paper [1], which applies an adaptive line search scheme and improves the convergence rate from O(1/N) for SVT to O(1/N2), where N is the number of iterations. In this paper, we show that it is the same as the Nemirovski’s approach, and then modify it to obtain an accelerate Nemirovski’s technique and prove the convergence. Our preliminary computational results are very favorable.

Predicting the Threshold Values based on Diffusion Model of Nitrite Ions in Reinforced Concrete

The prediction model for inhibition effect of reinforced concrete was presented based on the Magge＇s model when the concrete surface was brushed with nitrite solution. The influence of the amount of nitrite solution on inhibiting duration was also discussed through a simulation analysis when the amount of solution were 250 g/m^2, 500 g/m^2, 1000 g/m^2 and 1500 g/m^2, respectively. The experimental results confirm that nitrite ion can diffuse well in concrete to reach an effective mol ratio from the surface of the concrete to the surface of the reinforcement, and has an effective protection for the bars against corrosion. The higher the amount of solution, the better it will accelerate getting the threshold value of mol ratio on the surface of rebar, and retarding the time for loosing the effective threshold value of mol ratio. It helps to increase the tendency of inhibiting duration and prolong the life of reinforced concrete. The nitrite solution amount is used to predict the corrosion inhibiting duration of concrete that contains chloride salt.

THRESHOLD VALUE FOR DIAGNOSIS OF CHAOTIC NATURE OF THE DATA OBTAINED IN NONLINEAR DYNAMIC ANALYSIS

In this paper surrogate data method of phase-randomized is proposed to identify the random or chaotic nature of the data obtained in dynamic analysis: The calculating results validate the phase-randomized method to be useful as it can increase the extent of accuracy of the results. And the calculating results show that threshold values of the random timeseries and nonlinear chaotic timeseries have marked difference.

The Effect of a High-Frequency-Hearing-Threshold Weighted Value on the Diagnosis of Occupational-Noise-Induced Deafness

Objective: In order to provide a theoretical basis for the revision of the current diagnostic criteria for occupational noise-induced deafness (ONID), we evaluated the degree of ONID by analyzing different high-frequency-hearing- threshold-weighted values (HFTWVs). Methods: A retrospective study was conducted to evaluate the diagnosis of patients with ONID from January 2016 to January 2017 in Guangdong province, China. Based on 3 hearing tests (each interval between the tests was greater than 3 days), the minimum threshold value of each frequency was obtained using the 2007 edition’s diagnostic criteria for ONID. The speech frequency and the HFTWVs were analyzed based on age, noise exposure, and diagnostic classi-fication using SPSS21.0. Results: 168 patients in total were involved in this study, 154 males and 14 females, and the average age was 41.18 ± 6.07. The diagnosis rate was increased by the weighted value of the high frequencies and was more than the mean value of the pure speech frequency (MVPSF). The diagnosis rate for the weighted 4 kHz frequency level increased by 13.69% (χ2 = 9.880, P = 0.002), the weighted 6 kHz level increased by 15.47% (χ2 = 9.985, P = 0.002), and the weighted 4 kHz + 6 kHz level increased by 15.47% (χ2 = 9.985, P = 0.002). The differences were all statistically significant. The diagnostic rate of the different thresholds showed no obvious difference between the genders. The age groups were divided into less than or equal to 40 years old (group A) and 40 - 50 years old (group B). There were several groups with a high frequency: high frequency weighted 4 kHz ( group A χ2 = 3.380, P = 0.050;group B χ2 = 4.054, P = 0.032), high frequency weighted 6 kHz (group A χ2 = 6.362, P = 0.012;group B χ2 = 4.054, P = 0.032), weighted 4 kHz + 6 kHz (group A χ2 = 6.362 P = 0.012;B χ2 = 4.054, P = 0.032) than those of MVPSF in the same group on ONID diagnosis rate. The differences between the groups were statistically significant. There was no significant difference between the age groups (χ2 = 2.265, P = 0.944). The better ear’s (the smaller hearing threshold weighted value) MVPSF and the weighted values for the different high frequencies were examined in light of the number of working years;the group that was exposed to noise for more than 10 years had significantly higher values than those of the average thresholds of each frequency band in the groups with 3 - 5 years of exposure (F = 2.271, P = 0.001) and 6 - 10 years of exposure (F = 1.563, P = 0.046). The differences were statistically significant. The different HFTWVs were higher than those of the MVPSF values, and the high frequency weighted 4 kHz + 6 kHz level showed the greatest difference, with an average increase of 2.83 dB. The diagnostic rate that included the weighted high frequency values was higher for the mild, moderate, and severe cases than those patients who were only screened with the pure frequency tests. The results of the comparisons of the diagnosis rates for mild ONID were as follows: the weighted 3 kHz high frequency level (χ2 = 3.117, P = 0.077) had no significant difference, but the weighted 4 kHz level (χ2 = 10.835, P = 0.001), 6 kHz level (χ2 = 9.985, P = 0.002), 3 kHz + 4 kHz level (χ2 = 6.315, P = 0.012), 3 kHz + 6 kHz level (χ2 = 6.315, P = 0.012), 4 kHz + 6 kHz level (χ2 = 9.985, P = 0.002), and 3 kHz + 4 kHz + 6 kHz level (χ2 = 7.667, P = 0.002) were significantly higher than the diagnosis rate of the mean value of the PSF. There was no significant difference between the 2 groups for the moderate and severe grades (P > 0.05). Conclusion: Different HFTWVs increase the diagnostic rate of ONID. The weighted 4 kHz, 6 kHz, and 4 kHz + 6 kHz high frequency values greatly affected the diagnostic results, and the weighted 4 kHz + 6 kHz high frequency hearing threshold value has the maximum the effect on the ONID diagnosis results.

Optimized quantum singular value thresholding algorithm based on a hybrid quantum computer

Quantum singular value thresholding(QSVT) algorithm,as a core module of many mathematical models,seeks the singular values of a sparse and low rank matrix exceeding a threshold and their associated singular vectors.The existing all-qubit QSVT algorithm demands lots of ancillary qubits,remaining a huge challenge for realization on nearterm intermediate-scale quantum computers.In this paper,we propose a hybrid QSVT(HQSVT) algorithm utilizing both discrete variables(DVs) and continuous variables(CVs).In our algorithm,raw data vectors are encoded into a qubit system and the following data processing is fulfilled by hybrid quantum operations.Our algorithm requires O [log(MN)] qubits with0(1) qumodes and totally performs 0(1) operations,which significantly reduces the space and runtime consumption.

DWT-SVD Based Image Steganography Using Threshold Value Encryption Method

Digital image steganography technique based on hiding the secret data behind of cover image in such a way that it is not detected by the human visual system.This paper presents an image scrambling method that is very useful for grayscale secret images.In this method,the secret image decomposes in three parts based on the pixel’s threshold value.The division of the color image into three parts is very easy based on the color channel but in the grayscale image,it is difficult to implement.The proposed image scrambling method is implemented in image steganography using discrete wavelet transform(DWT),singular value decomposition(SVD),and sorting function.There is no visual difference between the stego image and the cover image.The extracted secret image is also similar to the original secret image.The proposed algorithm outcome is compared with the existed image steganography techniques.The comparative results show the strength of the proposed technique.

Efficient Global Threshold Vector Outlyingness Ratio Filter for the Removal of Random Valued Impulse Noise

This research paper proposes a filter to remove Random Valued Impulse Noise (RVIN) based on Global Threshold Vector Outlyingness Ratio (GTVOR) that is applicable for real time image processing. This filter works with the algorithm that breaks the images into various decomposition levels using Discrete Wavelet Transform (DWT) and searches for the noisy pixels using the outlyingness of the pixel. This algorithm has the capability of differentiating high frequency pixels and the “noisy pixel” using the threshold as well as window adjustments. The damage and the loss of information are prevented by means of interior mining. This global threshold based algorithm uses different thresholds for different quadrants of DWT and thus helps in recovery of noisy image even if it is 90% affected. Experimental results exhibit that this method outperforms other existing methods for accurate noise detection and removal, at the same time chain of connectivity is not lost.

Main Principles and Methods of Identification of High Conservation Value Forests in the Conditions of Mountainous Relief： Case of Armenia

Armenia is a small mountainous country with remarkable biodiversity. The forest cover of Armenia makes up 11.17% of the total territory of Armenia. The forests of Armenia make important habitat for numerous biological objects. They also provide important ecosystem services, including key services to forest adjacent population. Deforestation and forest degradation are serious threats in Armenia. In the result of special studies the principles and criteria for identification of HCVFs （high conservation value forests） in the conditions of Armenia were developed. They are based on the guidelines for identification and management of HCVFs, but adapted to the conditions of mountainous forests of Armenia as a small country. Out of six generic types of HCVFs, it is suggested to define five types of HCVFs with respective sub-types. Proper protection of such forests shall ensure conservation of biological diversity and maintenance of ecosystem services provided by forests.

A More Effective Method of Extracting the Characteristic Value of Pulse Wave Signal Based on Wavelet Transform

Pulse wave contains human physiological and pathological information. Different people will exhibit different characteristics, and hence determining the characteristic points of the pulse wave of human physiological health makes sense. It is common that we extract the characteristic value of pulse wave signal with the method based on wavelet transform on a small scale, and then determine the locations of the characteristic points by modulus maxima and modulus minima. Before determining characteristic value by detecting modulus maxima and modulus minima, we need to determine every period of the pulse wave. This paper presents a new kind of adaptive threshold determination method which is more effective. It can accurately determine every period of the pulse wave, and then extract characteristic values by modulus maxima and modulus minima in every period of the pulse wave. The method presented in this paper promotes the research utilizing pulse wave on health life.

Analysis of Network Traffic with Extreme Value Theory

It is very im portant to analyze network traffic in the network control and management. In thi s paper, extreme value theory is first introduced and a model with threshold met hods is proposed to analyze the characteristics of network traffic. In this mode l, only some traffic data that is greater than threshold value is considered. Th en the proposed model with the trace is simulated by using S Plus software. The modeling results show the network traffic model constructed from the extreme va lue theory fits well with that of empirical distribution. Finally, the extreme v alue model with the FARIMA(p,d,q) modeling is compared. The anal ytical results illustrate that extreme value theory has a good application foreg round in the statistic analysis of network traffic. In addition, since only some traffic data which is greater than the threshold is processed, the computation overhead is reduced greatly.

Application of Extreme Value Theory to Generation and Analysis of Pseudorandom Samples

The article deals with the methodology of pseudorandom data analysis. As a mathematical tool for carrying out the research the extreme value theory was used that creates one of the directions in mathematical statistics, and is related to investigating the extreme deviations from the median values in probability distributions. Also, the methods for estimating unknown parameters and algorithm of random-number generation are discussed. The models of treatment the extreme values are constructed which are based on machine generated sample and approach is proposed for their future application for constructing forecasting models.

Alarm Correlation Rules Generation Algorithm Based on Confidence Covered Value

In communication alarm correlation analysis,traditional association rules generation(ARG) algorithm usually has low efficiency and high error rate.This paper proposes an alarm correlation rules generation algorithm based on the confidence covered value.Confidence covered value method can judge whether a rule is redundant or not scientific After the rules that based on weighted frequent patterns(WFPs) generated,the association rules were deleted by the confidence covered value,in order to delete the redundant rules and keep the rules with more information.Experiments show that the alarm correlation rules generation algorithm based on the confidence covered value has higher efficiency than the traditional method,and can effectively remove redundant rules.Thus it is very suitable for telecommunication alarm association rules processing.

正常成人电刺激痛感觉阈与耐痛阈相关性及影响因素的多元线性回归分析

目的:测定正常成人在电刺激下的痛感觉阈(perception pain threshold,PTH)、耐痛阈(pain tolerance,PTO)水平,探讨影响因素,分析痛感觉阈、耐痛阈的关系,并建立正常成人的PTH、PTO参考值范围。方法:采用一元线性回归、多元线性回归分析等方法,回顾性分析2017年10月21日至2020年5月22日在陆军军医大学第一附属医院疼痛科使用体感诱发电位测量仪系统进行电刺激测试的正常成人痛阈相关数据,性别、年龄、职业、学历、婚姻、月收入、体质指数(body mass index,BMI)等一般资料。计算正常成人PTH、PTO参考值范围。结果:一元线性回归分析显示PTH与PTO的变化呈高度正相关(P<0.001)。分别以PTH、PTO的值为因变量,将性别、年龄、职业、学历、婚姻、月收入、BMI指数为自变量进行多元线性回归分析,结果表明性别是PTH、PTO的影响因素(P<0.001),不同性别PTH、PTO值有明显差异。男性、女性PTH、PTO的值均呈正态分布(P均<0.05),采用正态分布法计算男性PTH、PTO的95%参考范围分别为0.051~4.388、1.845~13.012,女性PTH、PTO的95%参考范围分别为0.146~3.069、1.521~10.207;男性PTH、PTO的平均值±标准差分别为2.219±1.224,7.429±8.115,女性PTH、PTO的平均值±标准差分别为1.608±0.556,5.864±4.910。结论:疼痛的敏感性女性高于男性,女性PTH、PTO正常值范围均较男性窄。疼痛的感受性与耐受性高度正相关。

长江中游河岸形态特征及稳定性判别阈值

三峡工程运用后,长江中游河床持续冲刷,局部段崩岸现象频发,威胁中游河道防洪安全。本文基于实测数据,揭示了中游河岸形态特征参数的统计规律,并提出了河岸稳定性的判别阈值。结果表明:中游各河段内水下坡比的概率密度总体上符合对数正态分布,当外界因素(来水来沙条件变化或护岸工程实施)导致河岸稳定性降低或增强时,其实际的分布规律会偏离对数正态分布,且其偏离程度可作为判定河段整体稳定性的依据;河型变化对河岸坡比的概率密度分布规律没有明显影响,但对于相对深泓位置的影响相对较为明显;上荆江、下荆江、城汉与汉湖河段的水下坡比阈值分别为>0.22、>0.18、>0.20和>0.28,大于下层河岸土体的休止角对应的坡比(约0.16),表明只有河岸下层土体冲刷到一定程度后,崩岸现象才会发生,符合其动力学过程;各河段内深泓位置的阈值均为离河岸小于平滩河宽的距离的10%。此外,采用提出的稳定性判别阈值确定了2020年长江中游易发生崩岸的区域分布,与实际巡查结果符合较好。

不同土地利用方式下文昌滨海贝屑沙土磷素组成与淋溶特性

土壤磷素(P)是作物必需的营养元素之一,也是农业生产中重要的养分限制因子,还是水体富营养化的重要污染源。以文昌滨海贝屑沙土为研究对象,应用石灰性土壤无机磷分级方法研究其形态组成,采用淋洗法评价其磷淋溶特性。试验结果表明:文昌滨海贝屑沙土磷素形态组成以Ca10-P(45.78%)为主,O-P(26.67%)与Ca8-P(11.27%)次之,Ca_(2)-P(2.97%)、Al-P(4.70%)和Fe-P(8.60%)的含量较少;耕地土壤Ca_(2)-P(28.35 mg/kg)和Ca8-P(93.74 mg/kg)含量显著高于林地土壤的Ca_(2)-P(3.95 mg/kg)和Ca8-P(42.31 mg/kg)含量;瓜菜和叶菜地土壤Ca_(2)-P和Ca8-P含量显著高于其他植被类型土壤的含量;土壤平均磷淋失量为2.92 mg/kg,占土壤总磷量的0.32%,占土壤有效磷(Olsen-P)含量的10.26%,Olsen-P淋溶阈值为51.13 mg/kg。

高桩码头结构安全监测预警模型及工程应用

高桩码头结构在服役期内会出现不同程度的损伤,导致码头结构安全性降低。为保证码头长期安全运行,可通过实时监测确定码头运行状态并及时预警。提出一种高桩码头结构安全监测预警模型,采用不同结构状态的设计控制值作为不同级别的预警阈值,每级预警阈值对应不同的风险程度,针对不同级别的预警提出相应处置措施。将该预警模型应用于南京港某高桩码头的安全监测,对可变荷载作用下码头结构位移和桩基应变进行实时监测,并计算设置码头结构位移和桩基应变三级安全预警阈值。结果表明,码头安全预警阈值的设置及安全告警的应对措施科学有效,实现了码头结构全工况整体技术状态评估和安全预警。

基于ISSA-VMD的地铁构架应力谱门槛值自适应确定方法

针对地铁构架应力谱编制过程中小应力循环舍弃缺乏标准可依的问题,提出基于改进麻雀搜索算法(ISSA)和应力-时间历程信号变分模态分解(VMD)的应力谱门槛值自适应确定方法。首先,通过融合Tent混沌映射、鱼鹰优化算法和柯西变异策略改进麻雀搜索算法,从而避免陷入局部最优,提高分析效率;其次,采用ISSA优化VMD的分解个数和惩罚因子,实现关键参数确定;最后,根据最优参数组合,对应力信号进行VMD分解,并结合疲劳损伤占比、均方根和均方误差等参数对分解得到不同分量信号的中心频率进行综合分析,提取损伤占比较大的信号频率作为截止频率,从频域层面实现小应力门槛值的确定。结果表明:采用此方法确定的小应力门槛值使得应力雨流循环总数降低17.1%,实际损伤较传统方法所得结果减少7.8%,在有效反映应力所造成疲劳效应的同时保留了应力循环特性,提高了应力谱编制效率,从而为地铁构架应力谱编制过程中小应力门槛值的合理确定提供了参考。

纺织企业国际化程度、研发投入与企业价值——基于门槛回归的经验证据

本研究以2018—2022年纺织类上市企业的面板数据为基础,采用非线性视角与资源有限性理论,运用门槛模型探讨了在不同国际化程度下,研发投入与企业价值之间的关系。研究结果显示:(1)当国际化程度作为门槛变量时,研发投入与企业价值之间呈现出倒U型关系,存在两个门槛值,最优区间为DI≤0.389;(2)研发投入滞后一期和滞后二期与企业价值的关系同样呈现倒U型,最优区间为DI≤0.383;(3)在135个样本企业中,有29.63%的企业国际化程度高于第一门槛值0.389,但未处于最优区间;(4)企业成长性和人力投入回报率与企业价值呈显著正相关,资产负债率与企业价值呈显著负相关。研究结果表明,我国纺织类企业的研发投入整体偏低,引导纺织企业加大研发投入仍是提升企业价值的重要路径。本文对我国纺织企业有效参与国际市场竞争、实现可持续发展具有重要的参考意义。

国内贸易网络与企业全球价值链地位——基于市场可达性的中介效应

现代经济生产与分工日渐网络化,促使国内贸易网络对企业全球价值链地位攀升的重要作用逐步凸显。文章基于2012—2022年我国上市公司和中国海关匹配数据,考察国内贸易网络对企业全球价值链地位的影响和作用机制。研究结果表明:国内贸易网络对企业全球价值链地位具有显著促进作用;中介机制检验结果显示,市场可达性在国内贸易网络影响企业全球价值链地位过程中发挥中介作用;门槛效应检验发现,在市场可达性较高地区,国内贸易网络对企业全球价值链地位的促进作用更强;异质性检验表明,国内贸易网络对企业全球价值链地位的正向影响在高生产率企业和中低质量产品企业中更显著。据此,文章提出跨区域拓展与延伸国内贸易网络、制定差异化扶持策略、借助于现有交通网络深化市场可达性等对策建议,以期更好助力企业实现全球价值链地位攀升。