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基于声信号汽车座椅水平驱动器产品的质量分析 被引量:2
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作者 唐艾君 张钊 刘立君 《机械工程师》 2014年第10期174-176,共3页
针对汽车座椅水平驱动器(Horizontal Driving Machine,简称HDM)零件加工和装配误差,导致少部分产品在运行过程中产生异常噪声信号,需要对现有产品进行优化升级,提出采用声信号检测新模具生产产品质量方法。首先建立水平驱动器声信号采... 针对汽车座椅水平驱动器(Horizontal Driving Machine,简称HDM)零件加工和装配误差,导致少部分产品在运行过程中产生异常噪声信号,需要对现有产品进行优化升级,提出采用声信号检测新模具生产产品质量方法。首先建立水平驱动器声信号采集系统,利用B&K PULSE-Automotive Sound Quality软件采集声信号;然后对采集的水平驱动器正反转声信号进行均方根和计权A声级分析。分析结果表明该均方根能有效分析新模具生产的水平驱动器质量差异,为水平驱动器产品升级提供了一种定量测试方法;采用计权A声级分析水平驱动器声信号,能更真实地反映人的主观听感,对产品噪声判断更加准确。 展开更多
关键词 汽车座椅水平驱动器 模具 声信号 方根 A计权声级分析
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基于虚拟仪器的声级计测试系统开发 被引量:3
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作者 邓召文 袁野 《拖拉机与农用运输车》 2019年第6期23-27,共5页
虚拟仪器是一种以计算机作为仪器来统一硬件的平台,它具有智能化程度高、复用性强以及可操作性强等优点。参照传统声级计的结构原理,采用MPA 201声压传感器、NI 9234采集卡等硬件,基于Labview软件进行虚拟声级计测试系统开发,实现对声... 虚拟仪器是一种以计算机作为仪器来统一硬件的平台,它具有智能化程度高、复用性强以及可操作性强等优点。参照传统声级计的结构原理,采用MPA 201声压传感器、NI 9234采集卡等硬件,基于Labview软件进行虚拟声级计测试系统开发,实现对声音信号的采集、时域分析、频域分析和计权分析功能。经试验验证,开发的虚拟声级计测试系统可扩展性强,操作面板简洁美观,功能完善,具有较好的可靠性与稳定性。 展开更多
关键词 声级计 虚拟仪器 LABVIEW 时频域分析 计权分析
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轨道包覆材料的降噪性能研究 被引量:1
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作者 柳桂华 李彬 +2 位作者 龚伟 刘祥 叶茂 《绿色环保建材》 2017年第10期5-6,8,共3页
为探讨双块式、套靴式、嵌条式轨腰包覆材料的降噪性能,以及有轨电车诱发环境噪声的传播和衰减特性,在距轨道中心线3.5m、7.5m、25m处布置测点,对有轨电车运行产生的环境噪声进行现测试,获取噪声连续等效A计权声压级,结果表明:在距离轨... 为探讨双块式、套靴式、嵌条式轨腰包覆材料的降噪性能,以及有轨电车诱发环境噪声的传播和衰减特性,在距轨道中心线3.5m、7.5m、25m处布置测点,对有轨电车运行产生的环境噪声进行现测试,获取噪声连续等效A计权声压级,结果表明:在距离轨道中心线3.5m处,双块式、套靴式、嵌条式包覆材料对于降低环境噪声均有效果,嵌条式包覆材料最好,双块式包覆材料次之,套靴式降噪效果一般。距离轨道中心线越远,由于环境因素的增加,三种包覆材料的降噪效果不明显。 展开更多
关键词 有轨电车 噪声实测结果分析 钢轨弹性体材料 连续等效A计权声压级分析
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A method for real power transfer allocation using multivariable regression analysis 被引量:6
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作者 Hussain Shareef Azah Mohamed +1 位作者 Saifunizam Abd.Khalid Mohd Wazir Mustafa 《Journal of Central South University》 SCIE EI CAS 2012年第1期179-186,共8页
A multivariable regression(MVR) approach is proposed to identify the real power transfer between generators and loads.Based on solved load flow results,it first uses modified nodal equation method(MNE) to determine re... A multivariable regression(MVR) approach is proposed to identify the real power transfer between generators and loads.Based on solved load flow results,it first uses modified nodal equation method(MNE) to determine real power contribution from each generator to loads.Then,the results of MNE method and load flow information are utilized to determine suitable regression coefficients using MVR model to estimate the power transfer.The 25-bus equivalent system of south Malaysia is utilized as a test system to illustrate the effectiveness of the MVR output compared to that of the MNE method.The error of the estimate of MVR method ranges from 0.001 4 to 0.007 9.Furthermore,when compared to MNE method,MVR method computes generator contribution to loads within 26.40 ms whereas the MNE method takes 360 ms for the calculation of same real power transfer allocation.Therefore,MVR method is more suitable for real time power transfer allocation. 展开更多
关键词 power tracing multivariable regression power systems DEREGULATION
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Human rights and political and economic instability
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作者 William R. DiPietro 《Chinese Business Review》 2010年第6期59-64,共6页
The purpose of this paper is to use cross country regression analysis on a large set of countries from around the world for the year 2007 to test the hypothesis that greater instability, political or economic leads to... The purpose of this paper is to use cross country regression analysis on a large set of countries from around the world for the year 2007 to test the hypothesis that greater instability, political or economic leads to reduced levels of human rights. The results of the paper's econometric analysis tend to support the hypothesis that increased levels of either political instability or economic instability are detrimental to human rights within countries. 展开更多
关键词 human rights level of economic development stability cross country analysis
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Application of whole body diffusion weighted imaging in bone metastasis 被引量:1
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作者 Xv Wu Changying Ma Xia Zhao Shaowu Wang 《The Chinese-German Journal of Clinical Oncology》 CAS 2010年第1期44-47,共4页
Objective: We evaluated (Whole-Body Diffusion Weighted Imaging, WB-DWl) application in bone metastasis. Methods: WB-DWI with GE 1.5T MR/I was performed on 10 healthy volunteers and 35 patients. WB-DWl and ECT was ... Objective: We evaluated (Whole-Body Diffusion Weighted Imaging, WB-DWl) application in bone metastasis. Methods: WB-DWI with GE 1.5T MR/I was performed on 10 healthy volunteers and 35 patients. WB-DWl and ECT was performed in all 35 patients. Using WB-DWl for detecting bone metastasis and compared them with that of ECT. Results: Background was suppressed in WB-DWl, fat, muscle, vessels and liver appeared same as background. Skeleton showed medium or slightly lower signal. Lymph nodes, some glandular organs, kidneys displayed medium signal. Spleen, testicle, brain tissue were low signal. Bladder, gallbladder were depicted as low signal because of "T2 through". Bone metastasis were multitude and inequality of size, punctiform, nodosity, column low intensity. Concordance between WB-DWI and ECT was seen in 4 cases. WB-DWl displayed 1 bone metastasis on skull, 46 on rib and sternum, 3 on scapula, 4 on extremities, 83 on vertebral, 36 on pelvic bone. ECT showed 2 bone metastasis on skull, 62 on rib and sternum, 7 on scapula, 9 on extremities, 64 on vertebral, 19 on pelvic bone. WB-DWl was 74% for bone metastasis on rib and sternum, ECT was 77%, 53% for vertebral and pelvic bone. All of the focus were statistics analyses, P 〈 0.05. Total probability distribution inequality if metastasis on different positions. Conclusion: WB-DWI was an effective imaging technology for screening bone metastasis. 展开更多
关键词 WB-DWt whole body imaging bone metastasis
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Research on the Application Security Isolation Model
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作者 Gong Lei Zhao Yong Liao Jianhua 《China Communications》 SCIE CSCD 2010年第6期153-156,共4页
Typical isolation models are studied and a New Application Security Isolation model called NASI is proposed, which is based on trusted computing technology and least privilege principle. This paper introduces the desi... Typical isolation models are studied and a New Application Security Isolation model called NASI is proposed, which is based on trusted computing technology and least privilege principle. This paper introduces the design ideas of NASI, gives out formal description and safety analysis for the model, and finally describes the implementation of prototype system based on NASI. 展开更多
关键词 application isolation security model application security protection
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Study on the Sequence in Formulating Standards for Acupuncture and Moxibustion
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作者 岗卫娟 杨莉 +3 位作者 武晓冬 訾明杰 王莹莹 杨金生 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2011年第2期136-140,共5页
Objective: To study which items need the formulation of national standards and which standards should be first formulated. Methods: Apply the method of the questionnaire survey to collect data, and the statistical a... Objective: To study which items need the formulation of national standards and which standards should be first formulated. Methods: Apply the method of the questionnaire survey to collect data, and the statistical analysis adopt the frequency and weighted average method. Results: Propose the items of acupuncture and moxibustion which need the urgent formulation of standards and the sequence in the formulation of standard items. Conclusion: Provid important bases for the follow-up report of national standard items and avoid temporary formulation of standards without plan . 展开更多
关键词 standards for acupuncture and moxibustion SEQUENCE formulate
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