基于多域流形的行星齿轮箱局部故障识别

行星齿轮箱振动信号包含多种频率成分和噪声干扰，频谱具有复杂的边带结构，容易对故障识别造成误导甚至引起错判.在不同故障状态下，行星齿轮箱振动信号的多域特征量将偏离正常范围且偏离程度不同，根据这一特点，提取振动信号的时域、频域特征参量用于故障识别.为了避免传统分析方法中负频率及虚假模态问题，增强对噪声干扰的鲁棒性，采用局部均值分解法将信号自适应地分解为单分量之和，提取时频域单分量瞬时幅值能量.针对多域特征空间构造过程中出现的高维及非线性问题，采用流形学习对数据进行降维处理.提出基于改进的虚假近邻点的本征维数估计及最优k邻域确定方法，并通过等距映射对多域特征空间进行降维分析.对于行星齿轮箱实验信号，根据样本流形特征聚类结果，分别识别出了太阳轮、行星轮和齿圈的局部故障，从而验证了上述方法的有效性.      

形态分量分析在滚动轴承故障诊断中的应用

滚动轴承局部故障振动信号中的周期性冲击是识别故障的关键特征.形态分量分析在由多种形态原子组成的过完备字典基础上提取信号中的不同形态成分,基于这种思想提出了一种基于新型过完备复合字典的形态分量分析方法.依据滚动轴承故障振动信号中分量间的形态差异性,改进字典后该方法可以更具针对性地提取出包含故障特征的冲击分量,配合包络谱分析准确提取故障特征频率,诊断滚动轴承局部故障.对比基于快速谱峭度法的轴承故障诊断方法,该方法可以避免人为选择共振带产生的不准确性和非最优问题,提高了故障诊断效果.通过轴承仿真信号和故障实验信号分析验证了该方法的有效性.      

基于集合经验模式分解和交叉能量算子的滚动轴承故障诊断

振动信号的周期性冲击及其重复频率是滚动轴承故障诊断的关键.本文提出了一种基于集合经验模式分解和交叉能量算子提取滚动轴承故障特征的方法.首先,应用集合经验模式分解方法将振动信号分解为本征模式函数以满足交叉能量算子对信号单分量的要求.然后根据相关程度和峭度从本征模式函数中选取敏感分量,计算敏感分量和原始信号的瞬时交叉能量及其傅里叶频谱.最后根据交叉能量的频谱结构和特征频率识别轴承故障.通过分析滚动轴承故障仿真信号和实验测试信号,诊断了滚动轴承元件故障,验证了该方法的有效性.     

基于小波包分解的转子叶片裂纹故障特征分析

应用小波包分解能对信号高、低频部分局部细化并保留原信号的时域特征,因而具有良好的时频局部化特性,对非平稳信号进行有效识别的技术,从采集到的有叶片裂纹时的振动信号,通过选取适当的频段进行信号重构,提取叶片裂纹故障的特征,从而实现转子叶片裂纹故障诊断。     

谐波小波解调法在齿轮箱故障诊断中的应用

在研究谐波小波频段分解与Hilbert解调分析的基础上,提出了基于谐波小波包变换的解调分析法,并详述了其具体实现过程.该方法根据齿轮箱频谱特征与齿轮箱故障特征频率的理论计算值,确定所需提取的特征啮合分量,并在此基础上选择谐波小波包分解层数与所需提取的频带带宽;通过傅里叶变换及其反变换提取出相应的特征啮合分量,然后借助Hilbert算子对提取出的啮合分量进行包络解调分析.采用这种方法对存在磨损及点蚀故障的齿轮箱振动信号进行了分析,结果表明,基于谐波小波包的包络解调法具有精确提取任意频段调制信息的能力,能够为齿轮箱故障源的准确定位及故障程度提供可靠的判断依据.     

基于变分模式分解和微积分增强能量算子的滚动轴承故障诊断

针对滚动轴承故障振动信号的特点,考虑变分模式分解在复杂信号分解及微积分增强能量算子在瞬态成分检测方面的优势,提出基于变分模式分解和微积分增强能量算子的滚动轴承故障诊断方法.首先利用变分模式分解将复杂信号分解为多个本质模式函数,以削弱背景噪声的影响和满足能量算子对信号单分量的要求;然后根据提出的敏感分量选取原则,从本质模式函数中选出包含主要故障信息的本质模式函数为敏感分量;最后利用微积分增强能量算子强化敏感分量中的瞬态冲击,并根据敏感分量瞬时能量的时域波形及Fourier频谱诊断滚动轴承故障.分析结果表明该方法能够有效诊断滚动轴承故障.      

基于EMD-RF的冷轧机振动信号时频分析及识别

冷轧板带生产中的振动机制复杂多变，工业生产过程采集到的历史数据中蕴含着设备运行状态与产品质量等关联信息，数据驱动的信息挖掘对实现振动状态监控与智能预测具有重要价值。首先针对实际工业生产中采集的历史振动信号进行数据预处理；然后对典型振动钢卷的信号进行经验模态分解，选取相关度较高的主要本征模态分量进行时频分析；随后，基于相关度最高的本征模态分量提取10个时频特征指标作为输入，以振动有效值作为输出标记，构建样本空间；最后，运用随机森林回归算法对多个材质和规格下的钢种振动信号进行识别。结果表明，所提出的经验模态分解与随机森林相结合的方法可以适应样本数量不平衡情况下的振动信号识别问题，能够为冷轧机振动的状态监控与智能预报提供依据。     

基于EEMD形态谱和支持向量机复合的滚动轴承故障诊断方法

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.     

大型连轧机传动齿轮在线故障诊断方法研究

在大型连轧机组中，主传动系统的减速机、齿轮在受着巨大的负载，很容易出现各种故障，采用神经网络自适应滤波方法和小波分解方法在线分析传动齿轮的振动信号，有效地分解出信号中由故障所引起的成分，地诊断出连轧机传动齿轮的各种故障原因，为大型连轧机组齿轮传动系统的故障在线监测提供了新的有效的工具。     

滚动轴承故障的诊断方法

本文在阅读国内外大量文献的基础上,综述了滚动轴承故障信号的检测方法。认为振动信号里所包含的故障信息最丰富,应用振动测试与分析诊断滚动轴承的故障最有效。讨论了从振动信号中提取滚动轴承故障特征的各种方法。     

Voices of fear and anxiety and sadness and depression: The effects of speech rate and loudness on fear and anxiety and sadness and depression.

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)     

Sexuality and aging--usual and successful

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.     

Synthesis and analysis of mixed chlorinated-fluorinated dibenzo-p-dioxins and dibenzofurans and assessment of formation and occurrence of the fluorinated and chlorinated-fluorinated dibenzo-p-dioxins and dibenzofurans

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.     

Spondylolysis and spondylolisthesis and sports

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.     

Larks and owls and health, wealth, and wisdom

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.     

IQ and ego-resiliency: Conceptual and empirical connections and separateness.

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)     

Conserving and retaining equalities and inequalities through observation and correction.

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)     

Reasoning and food and contamination.

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)     

Craniometaphyseal and craniodiaphyseal dysplasia, head and neck manifestations and management

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.