从“声音诊断”到“声音体验”:汽车声音的百年源流及涉众行动

在过去百余年中,汽车声音的角色和作用经历了错综复杂的演变,其中的思维和脉络将对认识现代汽车声音及其设计起到重要的启迪作用。本文将通过对汽车声音的角色作用、发展历史和涉众行动的梳理与分析,总结汽车声音演变的线索和逻辑,希望助力于汽车声音的实际应用设计和理论研究探索。

声音诊断技术在铁路客车滚动轴承检修中的应用

该文首先介绍声学诊断系统的原理、技术方式,阐述、分析了铁路客车滚动轴承的组成、工作原理、故障模式,分析了声音诊断技术的实现方式和关键性技术,探讨了声学诊断技术在铁路客车滚动轴承检修中的应用。

用声音诊断脑血栓新法

日本岩手医科大学近日宣布,已研究出的利用血液流动的声音检查脑血管堵塞的方法,已成为脑血栓症状的“声音诊断法”。这一诊断法将为早期发现脑血栓打开道路。诊断装置是由传感器、放大器和过滤器等构成。被诊断者躺在床上,把传感器放在额部,五分钟之后就可以诊断出结果。

基于深度学习模型的电力变压器故障声音诊断方法研究

利用声音信号对电力变压器进行故障诊断是一种不停机的设备维护方法,可以诊断变压器故障类型或预测故障产生的时间。声音诊断相对于其他诊断方式有许多优点,但是传统的声音自动诊断方法识别率不够理想。为了探索深度学习技术在声音故障诊断方面的可行性,本文采集了真实变压器在正常状态、老化和放电两种故障运行状态下发出的声音信号,对信号分别进行了声谱图转换和梅尔对数谱图的转换,输入一种高效轻量级卷积神经网络--Mobile Net深度学习模型中开展了训练。训练结果表明,将卷积神经网络应用在变压器故障声音诊断上能够得到较高的准确率,尤其是采用梅尔对数谱图对三种状态下识别准确率均能达到99%以上,而采用声谱图进行训练对放电类型的故障识别率较高,老化故障识别率不够理想。

基于LSTM神经网络的油浸式变压器异常声纹诊断方法研究

利用声音信号对电力变压器进行状态诊断是一种不停机、无接触的设备维护方法,可以诊断变压器异常状态类型。提出了一种基于LSTM神经网络的电力变压器异常诊断的方法,采集电力变压器在正常状态、过载和放电3种运行状态下发出的声音信号,将声音信号进行预处理并提取声音信号的MFCC特征,再将其通过一、二阶差分组合成一组声音特征的矢量,输入LSTM神经网络中进行训练。训练结果表明,将LSTM神经网络应用在电力变压器状态声音诊断上对3种状态的识别均能达到99%以上的准确率。

工业“听诊器”中声音处理电路的设计

采用单片机和专用集成电路 (MSM6 5 88,TA7796 ,TMS2 9F0 40 )设计实现声音数据的记录、回放电路等 ,研制成工业“听诊器” ,应用于工业设备的监测。对工业“听诊器”的组成、原理。

细胞神经网络

Applying the genetic programming to modeling of diffusion processes by using the CNN and its applications to the synchronization.Cellular neural network and its application in the diagnosis of abnormal automobile sound.Cellular neural network in image filtration tasks.Cellular neural networks and its application for abnormal detection - optimization of the cellular neural networks by designing an output function.

Spectral analysis of bowel sounds in intestinal obstruction using an electronic stethoscope

AIM: To determine the value of bowel sounds analysis using an electronic stethoscope to support a clinical diagnosis of intestinal obstruction. METHODS: Subjects were patients who presented with a diagnosis of possible intestinal obstruction based on symptoms, signs, and radiological findings. A 3MTH Littmann Model 4100 electronic stethoscope was used in this study. With the patients lying supine, six 8-second recordings of bowel sounds were taken from each patient from the lower abdomen. The recordings were analysed for sound duration, soundto-sound interval, dominant frequency, and peak frequency. Clinical and radiological data were reviewed and the patients were classified as having either acute, subacute, or no bowel obstruction. Comparison of bowel sound characteristics was made between these subgroups of patients. In the presence of an obstruction, the site of obstruction was identified and bowel calibre was also measured to correlate with bowel sounds. RESULTS: A total of 71 patients were studied during the period July 2009 to January 2011. Forty patientshad acute bowel obstruction (27 small bowel obstruction and 13 large bowel obstruction), 11 had subacute bowel obstruction (eight in the small bowel and three in large bowel) and 20 had no bowel obstruction (diagnoses of other conditions were made). Twenty-five patients received surgical intervention (35.2%) during the same admission for acute abdominal conditions. A total of 426 recordings were made and 420 recordings were used for analysis. There was no significant difference in sound-to-sound interval, dominant frequency, and peak frequency among patients with acute bowel obstruction, subacute bowel obstruction, and no bowel obstruction. In acute large bowel obstruction, the sound duration was significantly longer (median 0.81 s vs 0.55 s, P = 0.021) and the dominant frequency was significantly higher (median 440 Hz vs 288 Hz, P = 0.003) when compared to acute small bowel obstruction. No significant difference was seen between acute large bowel obstruction and large bowel pseudoobstruction. For patients with small bowel obstruction, the sound-to-sound interval was significantly longer in those who subsequently underwent surgery compared with those treated non-operatively (median 1.29 s vs 0.63 s, P < 0.001). There was no correlation between bowel calibre and bowel sound characteristics in both acute small bowel obstruction and acute large bowel obstruction. CONCLUSION: Auscultation of bowel sounds is nonspecific for diagnosing bowel obstruction. Differences in sound characteristics between large bowel and small bowel obstruction may help determine the likely site of obstruction.

The combined time-frequency analysis of the acoustic signals backscattered from ultrasonic contrast agents in the evaluation of the blood perfusion

Objective: To analyze the non-periodic, unstable and even chaotic echoes scattered from microbubbles which are extremely sensitive and may easily collapse, fragment or shrink when ultrasound contrast agents are exposed to ultrasound (US) irradiation. Methods: The combined time-frequency analysis was applied to the original signals instead of the traditional Fourier spectral analysis technique. Results: The results obtained from simulation as well as experiment showed that the subharmonic, 2nd harmonic and ultra harmonic of the microbubbles occurred during the oscillation and varied with time. The dependence on the incident ultrasonic amplitude and microbubble parameters were established. Conclusion: The transient echoes backscattered from the ultrasound agent in the evaluation of the blood perfusion can be analyzed thoroughly by the technique of combined-frequency analysis and the time detail of the frequency contents can be revealed.

“杂”论

缘于业务本身的接触面广,又具较强的综合性,新闻工作者理应当“杂家”,这恐怕是不言可喻的——“天地有正气,杂然赋流形”,大千世界,皆杂然也。社会众生相,更加复杂纷呈。“杂”者,看来是造物的适应。然而的确有过较长期的一段历史误会,“杂家”被认为大逆不道。当年曾提出过一个“响亮”的口号,要砸烂新闻系,为的是它一直奉行“杂家路线”云。 无征不信,还有案可查。曾几何时?一位社会地位不可谓不高、知名度也不低于上海滩其他杂文作者的杂文家,仅以发表一篇题为《杂家》的杂文招来了“棍子手”当头棒喝,被打得一佛出世二佛涅砵;“文革”时再次遭殃,连他的三个女儿都受株连。