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1.
针对矿山微震信号采集过程中通常会混入高频噪声的问题,提出了基于互补集合经验模态分解(CEEMD)和排列熵的降噪方法对微震信号进行降噪处理。使用CEEMD将信号分解成从高频到低频的数个本征模态函数;计算各模态分量的排列熵值定量表征其随机性程度;通过对含噪声信息较多的IMF分量进行小波阈值降噪,并通过信号重构得到降噪后的微震信号。仿真信号和真实微震信号降噪效果表明,基于CEEMD和排列熵的降噪效果优于CEEMD和EMD降噪法,该方法可以有效去除微震信号中的高频噪声,为微震信号的进一步分析提供技术支持。  相似文献   

2.
根据穿墙雷达动目标探测中人的运动多普勒信号属于非线性、非平稳信号的特点,分别采用经验模式分解(EMD)和整体平均经验模式分解(EEMD)将人.5种运动的多普勒信号分解为一系列本征模式函数(IMF).采用支持向量机(SVM)学习算法,将两种方法分解后的各IMF能量占总能量的百分比作为支持向量机分类器的特征向量进行模式识别,分析了特征向量维数对识别率的影响,比较了EMD和EEMD的识别率.EEMD能够消除EMD存在的模式混合问题,识别率更高,达到94%以上.  相似文献   

3.
针对滚动轴承的内圈、外圈和滚动体故障提出了一种新的诊断方法,该方法融合了集总经验模态分解(EEMD)、形态谱和支持向量机(SVM)三种方法的优势.首先,利用经验模态分解对滚动轴承故障振动信号进行分解,得到若干个具有物理意义的内禀模态分量(IMF);其次,基于最大能量法筛选出含有故障特征信息最丰富的一个内禀模态分量为故障诊断数据源;再次,对数据源在选定尺度范围内进行形态谱的提取,从而构造故障特征向量;最后,利用支持向量机对滚动轴承的三种故障进行诊断.研究结果表明,该方法能够有效地诊断出滚动轴承的三种故障,且具有很高的故障诊断正确率.  相似文献   

4.
孙杰  单鹏飞  彭文  张殿华 《钢铁》2021,56(6):67-74
 针对轧制过程实际数据噪声大、难以获取准确板形调控功效系数的问题,提出了一种融合集成经验模态分解(EEMD)和小波变换(WT)的数据降噪方法。将含有噪声的实际生产数据经过EEMD分解后,利用小波变换方法对噪声主导的本征模态分量(IMF)进行降噪处理,处理后的噪声分量与其余分量重构得到降噪后数据,并结合结构方程模型(SEM)计算得到板形功效系数。利用1 450 mm五机架冷连轧生产线实际数据进行试验,结果表明,EEMD-WT-SEM方法可以有效降低数据噪声,有效提升板形调控功效系数的准确性。  相似文献   

5.
鉴于小波类去噪法存在小波基和分解层数的选择问题、EMD类去噪法受限于端点震荡和模态混叠效应,将EEMD方法引入,对爆破振动原始信号进行去噪研究。在EEMD分解的基础上,通过波形和频谱分析,得到IMF4~IMF8属于爆破振动真实信号分量,将其重构,获取了爆破振动真实波形。与EMD去噪法相比,EEMD去噪法避免了端点震荡和模态混叠效应的影响,不仅有效去除了噪声,还保留了爆破真实波形的真实性和完整性。  相似文献   

6.
声发射源的准确分类识别是声发射地压监测预报预警研究的重要基础。针对矿山井下围岩体声发射事件信号和采掘作业噪声信号分类识别问题,提出了一种基于改进完备总体经验模态分解和深度卷积神经网络(DCNN)的智能识别分类方法。首先,对信号进行改进CEEMDAN降噪处理,即利用相关性系数阈值和排列熵(PE)阈值剔除伪分量和噪声分量;然后,利用DCNN对降噪后的信号自动提取高维特征;最后,将特征用于softmax分类器分类识别,实现智能化井下信号源多分类。研究表明:改进CEEMDAN能够有效剔除伪分量及噪声分量;相比其他机器学习方法,改进CEEMDAN-DCNN方法具有准确率高和稳定性较好等优点。信号源识别分类方法研究为地压监测预警预报提供了重要的基础数据,准确的灾害预警预报可为矿山井下作业人员和设备提供安全保障。  相似文献   

7.
当前球磨机负荷检测方法难以准确评估磨机内部变化,给磨机综合运行状态的控制和优化带来较大难度。本文设计了一款内嵌加速度传感器且与钢球介质物理性质相一致的智能磨矿介质用于识别磨机负荷,开展了不同充填率等磨矿条件下的磨矿试验,设计磨矿效果系数划分磨机负荷状态;分别采用了卷积神经网络方法(CNN)和优化的支持向量机(SVM)模型对智能磨矿介质获取的加速度信号进行球磨机负荷识别。基于优化的SVM模型将获取的一维加速度信号进行互补集合经验模态分解算法(CEEMD)去噪、时域特征值和样本熵提取等预处理,将上述磨机负荷的特征向量分别输入GA?SVM、GS?SVM、PSO?SVM分类模型进行训练,研究表明,PSO?SVM模型的识别准确率可达98.33%,但存在训练过程繁琐,耗费时间长的问题。在图像识别领域具有优秀应用能力的CNN模型是把智能磨矿介质检测加速度信号数据转换为二维图片后直接输入基于VGG19网络的CNN模型进行分类识别,磨机负荷分类识别准确率高于优化的SVM模型,可达98.89%,在保证识别准确率的同时有效节约了计算时间。基于CNN的智能磨矿介质球磨机负荷识别方法可为实现球磨机负荷检测与在线评估提供重要解决方案与技术保障。   相似文献   

8.
为了去除露天矿山爆破振动信号中混入的噪声成分,提出了一种基于PEMD-MPE算法的降噪方法。该算法通过自适应性正交经验模态分解(PEMD)得到完全正交的本征模态函数(IMF)分量,然后对各个IMF分量进行多尺度排列熵(MPE)的随机性检测,成功确定其中的噪声分量并将其去除。采用该算法对实测的露天矿山爆破振动信号进行降噪处理。结果表明:相比EMD-MPE和EEMD-MPE算法,PEMD-MPE算法的信噪比分别提高了3.520 dB和1.107 dB,且重构标准差和均方根误差最小,说明该算法不仅能够有效去除爆破振动信号中的噪声成分,还能有效保留真实信号。  相似文献   

9.
 针对石油套管缺陷超声无损检测(NDT)中缺陷回波的特点,提出了一种基于小波包分解和支持向量机(SVM)的缺陷智能识别新方法。分析了Gabor、小波和小波包3种信号时频变换分解方法的特点,并进行了基于3种方法生成的特征数据可分性比较,确定了小波包分解方法效果最好。根据SVM解决分类问题的原理,采用SVM法对3种时频分解提取的缺陷信号特征数据进行识别。试验表明,基于小波包分解局部熵的特征提取结合SVM模式智能识别的组合方法,可应用于石油套管上的4种典型缺陷的识别。  相似文献   

10.
为精准识别矿山微震信号,采用改进深度卷积神经网络(DCNN)法,通过傅里叶变换得到的频谱图叠加原始图像的空间域图作为微震信号的识别对象,提出了一种基于改进DCNN法的微震信号自动识别与分类模型,建立了某铅锌矿的IMS微震监测信号数据库的训练集、验证集和测试集,并通过实际工程数据验证了方法的可靠性。结果表明:利用频谱图和空间域图在BGR通道上堆叠的特征值作为DCNN输入的方法,构建的微震信号自动识别模型精度更高且泛化能力更强,该模型能够高效地提取微震信号特征;采用F1值、ROC曲线和AUC值3种性能度量进行评价,验证了改进方法的可行性、有效性和可靠性。  相似文献   

11.
12.
Two studies investigated the role of expressive vocal behavior (specifically, speech rate and loudness) in fear and anxiety and in sadness and depression. In the 1st study, participants spoke about personally experienced fear and anxiety-arousing and neutral events using 3 different voice styles: fast and loud, normal, and slow and soft. In the 2nd study, participants spoke about personally experienced sad or depressing and neutral events using the same 3 voice styles. In both studies, the participants' highest levels of subjective affective and cardiovascular (CV) arousal occurred when they spoke about the emotional events in a mood-congruent voice style: fast and loud in the case of fear and anxiety, and slow and soft in the case of sadness or depression. Mood-incongruent voice styles canceled the heightened levels of CV arousal normally associated with these negative emotions. The voice-style manipulation had no significant effect on the participants' levels of CV arousal during the neutral discussions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
BACKGROUND: As aging research increasingly reflects an effort to dissociate true time-driven changes from those that can be improved, sexuality in later life remains largely unexplored. Several problems are evident. There is a lack of normative data, a lack of a conceptual framework relating to the biology, psychology, and sociology of sex, and an attitudinal resistance that obscures the entire topic. METHODS: We conducted a three-part instructional series on major topics involved with sexuality and aging. We surveyed our group of attendees (n 158, average age 68 for males, 65 for females) before and after the series. RESULTS: A remarkably robust sex life was evidenced by both the men and the women, even until advanced old age. Yet, a substantially decreased involvement was reported from 10 years earlier. Despite current activities, people of both sexes wished they were participating even more than they currently were. Impotency was identified as the major negative feature for the men; relationship problems were for the women. A questionnaire 6 months after the series reported improved sexual attitudes, but no change in sexual activities from the earlier survey. CONCLUSION: Sexuality is a major quality-of-life issue which persists into old age. Our study showed that the usual sexual practices reported by our group were not considered by them to be ideal. The intervention of this instructional series provided improved sexual attitudes but not performance. Additional studies are encouraged.  相似文献   

14.
Despite the use of multimodal therapy, higher-grade glioma is still uniformly fatal in the adult population. There is a considerable difference between the length of survival in each given patient, even within the same tumor type and malignancy grade group, suggesting that there are factors that might differentially influence outcome. To identify such factors, 107 patients with anaplastic or malignant glioma were retrospectively investigated. Clinical parameters and paraclinical data on the p53, mdm2, and EGFR genes at the DNA or protein level were evaluated by univariate analysis and Cox proportional hazards regression modeling. Kaplan-Meier survival estimation demonstrated that immunohistochemical positivity for mdm2 protein in patients with anaplastic astrocytoma or with glioblastoma multiforme was associated with a shorter survival time (p = 0.02). P53 gene mutations and immunopositivity for the epidermal growth factor receptor (EGFR) protein were not significantly related to poor prognosis. The Cox proportional hazards model revealed immunohistochemical positivity for p53, mdm2, or for both of them, the presence of postoperative irradiation, and the extent of surgical resection of tumor to be variables significantly associated with prolonged survival. EGFR overexpression, age over 60 years, and Karnofsky performance score below 40 points did not significantly shorten survival time. In conclusion, the present study identified immunohistochemically detected mdm2-protein overexpression as a statistically significant negative prognostic parameter in patients bearing anaplastic or malignant glioma. Association analysis of variables revealed a possible correlation between mdm2 and p53, which is also consistent with the biological interaction mode of both proteins in vivo.  相似文献   

15.
OBJECTIVE: To test the validity of Benjamin Franklin's maxim "early to bed and early to rise makes a man healthy, wealthy, and wise." DESIGN: Cross sectional analysis of sleeping patterns in a nationally representative group of elderly people, and longitudinal investigation of mortality. SETTING: Eight areas in Britain (five in England, two in Scotland, and one in Wales). SUBJECTS: 1229 men and women aged 65 and over who in 1973-4 had taken part in a survey funded by the Department of Health and Social Security and for whom data on sleeping patterns, health, socioeconomic circumstances, and cognitive function had been recorded. MAIN OUTCOME MEASURES: Self reported income, access to a car, standard of accommodation, performance on a test of cognitive function, state of health and mortality during 23 years of follow up. RESULTS: 356 people (29%) were defined as larks (to bed before 11 pm and up before 8 am) and 318 (26%) were defined as owls (to bed at or after 11 pm and up at or after 8 am). There was no indication that larks were richer than those with other sleeping patterns. On the contrary, owls had the largest mean income and were more likely to have access to a car. There was also no evidence that larks were superior to those with other sleeping patterns with regard to their cognitive performance or their state of health. Both larks and owls had a slightly reduced risk of death compared with the rest of the study sample, but this was accounted for by the fact that they spent less time in bed at night. In the study sample as a whole, longer periods of time in bed were associated with increased mortality. After adjustment for age, sex, the presence of illness, and other risk factors, people who spent 12 or more hours in bed had a relative risk of death of 1.7 (1.2 to 2.5) compared with those who were in bed for 9 hours. The lowest risk occurred in people who spent 8 hours in bed (adjusted relative risk 0.8; 0.7 to 1.0). CONCLUSION: These findings do not support Franklin's claim. A "late to bed and late to rise" lifestyle does not seem to lead to socioeconomic, cognitive, or health disadvantage, but a longer time spent in bed may be associated with increased mortality.  相似文献   

16.
Spondylolysis and spondylolisthesis occur predominantly in the lower lumbar spine. Besides congenital defects such as predisposition of spondylolysis the correlation between competitive sports activities and an increased incidence of spondylolysis is proved. In early stages, complete healing can be achieved by conservative treatment (abstinence from sports activities for 3 months, orthesis). Persistence of pain, neurologic symptoms and progression of vertebral slipping are indications for operative treatment (reconstruction of the isthmus, dorso-ventral spondylodesis). The exercise tolerance depends on the extent of instability, progression of vertebral slipping and clinical symptoms. The limits of exercise tolerance vary among the individual athletes and require the decision of the physician. Backstroke swimming, abdominal and back muscle strengthening exercises, and types of sport involving smooth movements are advisable. Sports education in school is possible without restriction in patients with stable spondylolysis and in those with spondylolisthesis without unfavourable concomitant factors.  相似文献   

17.
The constructs of intelligence and ego-resiliency are discussed. The personality implications of "pure intelligence" and "pure ego-resilience" were identified. Intelligence (IQ) was indexed by the Wechsler Adult Intelligence Scale-Revised (WAIS—R) and ego-resiliency by an inventory scale. Residual scores measuring "pure intelligence" and "pure ego-resilience" were correlated with the items of the observer based California Q-sort, used to describe participants. Persons relatively high on ego-resilience tend to be more competent and comfortable in the "fuzzier" interpersonal world; persons defined primarily by raw IQ tend to be effective in the "clearer" world of structured work but tend also to be uneasy with affect and less able to realize satisfying human connections. Gender differences exist in the relations of ego-resilience and intelligence and in their adaptive relevance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

18.
Investigated the effects of modeling and corrective feedback on the conservation of equalities and inequalities, with items spanning 3 stimulus dimensions (length, number, and 2-dimensional space). Ss were 48 kindergartners (24 boys, 24 girls). Brief observation of a model, briefer correction training (joining positive feedback with verbal rule provision), and the combination of observation and correction were all successful in producing learning and, without further training, transfer and retention of conservation. Unlike the controls (who also never correctly answered any equality items), the trained experimental Ss gave evidence of spontaneously generalizing their new learning to a task that required nonverbal behavior to manifest conservation. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

19.
Examines strategies that are used to reason about food and contamination. In Exp 1, Ss refrained from choosing a substance that had been given a "poison" label when the intent of the labeler was ambiguous or malicious but preferred this substance when a rationale was provided that dispelled the implication that there once might have been contaminants present. Exp 2 was designed to compare the effects of safety on conditional reasoning in food and food-irrelevant contexts. When the safety issue was relevant to food in the form of contamination, Ss were most likely to use formal logic in reasoning. A similar pattern of responses was found in Exp 3 on tasks for which Ss' ratings of their experience of contexts were matched for plausibility, experience, and danger. Results are discussed in terms of an adaptive constraint that facilitates rationality in reasoning within the food domain (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
Mechanical allodynia (MA) following hand injury is a well-documented clinical problem. The purpose of this pilot study was to examine the relationship between hand MA and the upper limb tension test (ULTT). The ULTT mechanically stresses the neural structures from the C5/6/7 neural foramina to the median nerve distally. This study examined 29 subjects with unilateral hand MA before and after a 2-week neural self-mobilization programme. There was a significant difference between the subjects' affected and unaffected sides when tested using the ULTT, both in reproduction of symptoms and in reduced range of motion of the ULTT. Following the self-mobilization program, there was an improvement in the range of the ULTT, and subjects reported a reduction in their symptoms. Complete recovery was not obtained in all cases. The results of this study suggest that the ULTT is a useful tool both in assessment and treatment of subjects with hand MA.  相似文献   

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