近场声全息技术在电机轴肋板故障检测中的应用

机械设备的安装环境随需求的变化而变化。为了实现电机轴肋板在各种工况下的故障检测,通过采集电机工作时肋板的振动信息,采用图像处理的方法,将故障下的特征向量与标准正常状态下的特征向量对比后进行分类,从而辨识出故障的类别。通过模拟仿真和实验两种方式对声成像方法进行验证,证明了其正确性和普遍适应性。声成像检测方法,不仅解决了检测机械设备的传感器在某些工作环境中安装不便的问题,而且进一步提高了故障检测的准确性。     

新型的机床安装支承垫——减震器

我厂长期以来一直使用传统的机床安装方法——把地脚螺钉预埋入水泥基础中,再用机床垫铁调整机床水平。这种安装方法费用高、周期长、安装人员劳动强度大。八五年我厂新建一座厂房,要搬迁安装设备百余台,我们采用整板基础(即地坪)和机床弹性支承垫——减震器,安装了车、铣、磨、插、拉等54台金切机床,安装周期缩短一个月,并降低了安装我厂长期以来一直使用传统的机床安     

小型安装工程中的施工管理及优化

安装工程是我们建设工程中重要组成部分，每一项安装项目不仅要做到质量过关、工期达标、安全可靠，还要保证工程项目盈利、将施工成本降至最低。本文以油田内部最普遍、数量最多的安装工程为例，说明小型安装工程施工组织中存在的问题和优化方法，从而缩短施工周期、降低施工成本。     

大型干熄焦提升机动滑轮新型更换方法的应用

一种干熄焦提升机动滑轮组更换方法属于干熄焦领域。采用根据动滑轮组中主轴尺寸自我研发新工具-轴套,更换滑轮组前将所有除主轴外部件安装在轴套上,将其吊装到安装位。之后将主轴从动滑轮组吊耳一侧用千斤顶直接顶入吊耳及轴套内,通过主轴再将轴套顶出,最终将主轴顶到安装位。此提升机动滑轮组更换方法检修时间可缩短一半,减少了干熄焦停产检修时间,进而大大减少了因干熄焦停产而造成的经济损失,同时也减少人工成本。     

转炉一次除尘快速安装工艺研究

炼钢厂氧气顶吹转炉一次除尘改造工程中,需安装的设备多、线路长、精度要求较高。为实现快速安装要求,通过安装工序及施工方法研究,采取分段同步施工、打通新通道、管道设备空中倒装等施工工艺,提高施工效率,缩短工期,创造了较好的效益。     

三缸结构水压机安装工作缸的新方法

我厂1250吨三缸结构水压机大修理时.安装工作缸采用了预先组装侧工作柱塞→缸体(中间工作缸.侧工作缸)→上横梁部件的方法(见图示)在活动横梁8和上横梁定位螺母6找正水平后.吊入中间柱塞5并定位;套入密封套。将侧柱塞密封压套套在球形支承上.然后将组装好的上横梁部件3沿中间柱塞套入立柱7座落在定位螺母6上。这样的安装方法,不仅省去了防止侧工作柱塞4倾倒面采用安全绳的措施,而且使缸体在上横梁3中就位和固定操作方便。另外,上横梁部件的组装工作可以和整个水压机安装工作同时进行.缩短网络计划     

真空检漏技术在真空感应炉安装中的应用

根据真空感应炉真空系统的特点,结合真空检漏技术原理和方法,选择氦质谱检漏仪法进行真空感应炉安装中的真空检漏,归纳出真空感应炉各种常见漏点和具体处理方法,缩短了真空感应炉的安装验收过程,提高了工作效率。     

多类型仿真数据生成软件设计

针对被监测运动机械设备,由于其工作环境复杂使得工况影响因子多,实验模拟其往往难以实现。为实现实际工况中非线性和线性信号等众多类型叠加信号,本文采用模拟信号设计满足需求的软件系统,并根据实际需求通过通信组件实现其信号的外部调用,满足用户实验和测试需求。实验表明该系统能模拟不同情况下多型信号,可以用于满足实验和测试需求,缩短研发周期。     

热等离子体热解煤焦油制乙炔过程的六西格玛研究

利用六西格玛设计方法对热等离子体热解煤焦油制乙炔过程进行了研究。使用过程失效模式及后果分析、可靠性设计分析和过程工艺参数分析确定了影响乙炔收率和煤焦油转化率的两个关键因素。通过测量系统误差分析确保实验中得到准确的实验结果。通过初步实验分析采用响应曲面双中心点实验设计方法进行了热解实验。实验结果表明该实验方法不仅减少了实验次数,缩短了实验周期,还提高了实验精度。JMP软件分析结果表明实验数据准确可高,误差小,完全达到六西格玛项目要求。实验中取得的乙炔收率最高为26.5%,煤焦油转化率最高为99%。乙炔收率和煤焦油转化率均随着输入功率和热等离子体中氢浓度的增加而升高,输入功率对乙炔收率和煤焦油转化率影响的波动较大。     

浅析石油化工装备安装过程中的施工管理

施工管理在石油化工装备安装过程中扮演者十分重要的作用,对所安装的装备质量、施工成本以及施工工期都有着重要的影响.有效的施工管理将会使石化装备安装过程更加有序、缩短施工工期和保证施工质量.本文将通过对石化装备安装基础进行解析,并且阐明石化装备安装过程中施工管理的规范以及具体做法.     

Probability Distribution of the Project Payback Period Using the Equivalent Cash Flow Decomposition

For stochastic cash flows, probabilistic approaches to determine a complete distribution of payback period are very limited. The payback analysis based on the net present value (NPV) has several advantages. For annual cash flows, however, the NPV-based method does not provide a complete payback distribution. This article proposes a new technique, the equivalent cash flow decomposition (ECFD), which converts an annual cash flow into an equivalent subannual cash flow at a desired level of precision. The ECFD technique can be used in conjunction with any probabilistic cash flow technique. This article demonstrates that the ECFD technique overcomes the discontinuity limitation of the conventional NPV-based payback period method and generates a complete distribution of the payback period of annual cash flows. Examples indicate that the proposed method is robust with the accuracy comparable to Monte Carlo simulation.     

A systematic technique for new product idea generation: the external brain

The author outlines a novel computer-based technique to generate ideas for new products. Essentially the technique uses the so-called Dialog databank, claimed to have access to 152 million units of information, to search for all publications in the database which combine a root concept and words such as idea, innovation, novelty, and so on. The computer can then be instructed to print out the titles of a restricted number defined by the searcher from each database accessed. The searcher can then study the contents of each publication at leisure. In principle other similar databanks can be used.
The technique is illustrated by two hypothetical cases: new uses for water and new uses for metal-powder technology.
The author claims that the technique will generate a large number of ideas in a short time at low-cost, can be used selectively (eg to search within a stated time-period), will link otherwise unrelated disciplines, and is well suited to brainstorming. The main drawbacks are that much of the information may be irrelevant, it cannot provide entirely new ideas though it can link existing concepts in a new way, and it cannot print out the total text from an identified source.     

一种序列图像中的人脸提取算法

主元分析法是一种有效降低维数和提取特征的方法,在对主元分析法改进的基础上,提出了一种运动目标检测及人脸提取技术。首先以3帧原始图像序列为训练集,用改进的主元分析法计算特征向量,其中第1特征向量和第2特征向量的乘积代表了原图像序列中的运动对象,将这个特征向量定义为特征前景;然后,用平方投影函数提取特征前景中的人脸。实验结果表明,该方法可自动提取运动图像序列中的人脸,且计算简单,准确率高。     

钢管无损检测中的磁致伸缩导波技术试验研究

为了研究磁致伸缩导波技术对输气和输液钢管缺陷的无损检测能力,基于磁致伸缩导波检测技术,设计了磁致伸缩导波检测装置。在同一频率下分别对4根充气和充液管道不同位置的已知缺陷进行导波无损检测试验,其方法是主机产生特定大功率信号,输入到激励传感器,磁致伸缩效应在管道中产生导波,对采集信号进行数据处理,判断管道已知的焊缝及法兰有无及位置。试验结果验证了磁致伸缩导波技术对输气和输液管道无损检测的可行性,证明了该技术能够较好地检测到充气直管焊缝、法兰及支撑结构等管道突变缺陷及位置,但较难应用于弯管的检测,充液管道能够被检出缺陷,但较输气管道的衰减大,检测距离将大幅衰减。     

The Evaluation of Risk in Marine Capital Investments

Future costs and revenues in capital investment opportunities can seldom be predicted with certainty. As a result, there is usually some doubt as to the outcome of an investment. The chance that an investment may not prove profitable represents the investor's risk. This paper considers the problems which uncertainty and risk present in the evaluation of capital investments. Several traditional methods of dealing with uncertainty and risk are considered and shown to be deficient. A relatively new evaluation technique, which utilizes probability theory and computer simulation, is then described and its advantages highlighted. It is suggested that this technique will prove valuable in the evaluation of future marine capital investments.     

Toward more accurate contextualization of the CEO effect on firm performance

We introduce multiple refinements to the standard method for assessing CEO effects on performance, variance partitioning methodology, more accurately contextualizing CEOs' contributions. Based on a large 20‐year sample, our new ‘CEO in Context’ technique points to a much larger aggregate CEO effect than is obtained from typical approaches. As a validation test, we show that our technique yields estimates of CEO effects more in line with what would be expected from accepted theory about CEO influence on performance. We do this by examining the CEO effects in subsamples of low‐, medium‐, and high‐discretion industries. Finally, we show that our technique generates substantially different—and we argue more logical—estimates of the effects of many individual CEOs than are obtained through customary analyses. Copyright © 2013 John Wiley & Sons, Ltd.     

相当梁法绘制简单刚架弯矩图

本文介绍了画简单刚架弯矩图的一种新方法,文中提出了相当梁的概念,将画简单刚架弯矩图的问题转化为画相当梁弯矩图的问题,该方法简单易懂易用。     

关联规则挖掘算法在教学管理上的应用

介绍了关联规则挖掘的基本概念,分析了经典的Apriori算法,提出一种改进的关联规则挖掘算法,在系统中永久保留支持度为0的候选1项集和候选2项集,当系统需要运行时,先采用数据库的过滤技术,可以很快得到频繁2项集。采用新算法在教学数据库中搜索所有的关联规则,从而得到课程与课程之间的关联关系,对教学管理具有一定的辅助决策意义。     

A Simple Bayesian Procedure for Sample Size Determination in an Audit of Property Value Appraisals

The article proposes a simple Bayesian technique for auditing property appraisals to determine whether state accuracy guidelines are met. The proposed technique addresses elicitation of appraisers' prior beliefs, computation of reappraisal sample sizes and reporting of audit results. To facilitate communication of quantitative audit findings to nonstatistician stakeholders, the concept of variance appears nowhere in prior elicitation or reporting. In contrast to classical frequentist techniques, the Bayesian procedure easily integrates expert judgment and responds flexibly to the arrival of new information. In addition, the Bayesian procedure significantly reduces the number of reappraisals required to regulate appraisal systems when they are functioning well. The technique can be applied in other settings where government officials audit their own work and must convince overseers, especially the public, that accuracy requirements are satisfied.     

联合站加药计量方式探讨

针对目前石油企业联合站破乳剂加药计量和加药速度调节的现状，对常用流量计进行了分析，介绍了变频控制原理，提出应用工程数学技术，结合工作实际，介绍了一种计量和控制的新方法，并以孤岛采油厂孤一联合站为例，进行了试验对比。