Tool wear estimation using an analytic fuzzy classifier and support vector machines

A new type of continuous hybrid tool wear estimator is proposed in this paper. It is structured in the form of two modules for classification and estimation. The classification module is designed by using an analytic fuzzy logic concept without a rule base. Thereby, it is possible to utilize fuzzy logic decision-making without any constraints in the number of tool wear features in order to enhance the module robustness and accuracy. The final estimated tool wear parameter value is obtained from the estimation module. It is structured by using a support vector machine nonlinear regression algorithm. The proposed estimator implies the usage of a larger number and various types of features, which is in line with the concept of a closer integration between machine tools and different types of sensors for tool condition monitoring.     

Ferrofluid actuation with varying magnetic fields for micropumping applications

Magnetic nanoparticle suspensions and their manipulation are becoming an alternative research line. They have vital applications in the field of microfluidics such as microscale flow control in microfluidic circuits, actuation of fluids in microscale, and drug delivery mechanisms. In microscale, it is possible and beneficial to use magnetic fields as actuators of such ferrofluids, where these fluids could move along a dynamic gradient of magnetic field so that a micropump could be generated with this technique. Thus, magnetically actuated ferrofluids could have the potential to be used as an alternative micro pumping system. Magnetic actuation of nanofluids is becoming an emergent field that will open up new possibilities in various fields of engineering. Different families of devices actuating ferrofluids were designed and developed in this study to reveal this potential. A family of these devices actuates discrete plugs, whereas a second family of devices generates continuous flows in tubes of inner diameters ranging from 254?μm to 1.56?mm. The devices were first tested with minitubes to prove the effectiveness of the proposed actuation method. The setups were then adjusted to conduct experiments on microtubes. Promising results were obtained from the experiments. Flow rates up to 120 and 0.135?μl/s were achieved in minitubes and microtubes with modest maximum magnetic field magnitudes of 300?mT for discontinuous and continuous actuation, respectively. The proposed magnetic actuation method was proven to work as intended and is expected to be a strong alternative to the existing micropumping methods such as electromechanical, electrokinetic, and piezoelectric actuation. The results suggest that ferrofluids with magnetic nanoparticles merit more research efforts in micro pumping.     

Optimization of a Fabric Softener Formulation with an Electrochemical Sensor and Streaming Potential Measurements

An electrochemical, cationic, surfactant-selective sensor based on multiwalled carbon nanotubes (MWCNT) functionalized with a sulfate group and the cetylpyridinium ion (MWCNT–OSO₃⁻CP⁺) as a sensing material was used for optimization of the formulation of a fabric softener. Potentiometric titrations were performed and response measurements were obtained using four cationic surfactants (CS) of technical grade and four CS of analytical grade. The slope closest to Nernstian was obtained for di-(tallow carboxyethyl) hydroxyethyl methylammonium methosulfate (MAS) (59.5 ± 1.1 mV/decade of activity in water and 57.5 ± 1.3 mV/decade of activity in CaCl₂). When using CS as analytes in potentiometric titrations, the best accuracy (99.8%) was obtained when using MAS; therefore, it was chosen as the CS for the fabric softener formulation. Due to the better properties of fabric softeners with silicone in their formulations, four silicones at several concentration levels were used as potential additives. Based on the stability and viscosity of the system, the diquaternary polydimethylsiloxane (DPS) (w = 0.19%) was chosen for the fabric softener formulation. The pH did not significantly influence the potential when in the range of 3–8 or the recovery of potentiometric titrations when in the range of 3–7. The application profile of the CS was assessed through streaming potential measurements of reference fabrics in an electrokinetic analyzer. The obtained electrokinetic parameters indicated on lag in adsorption of model fabric softener (MFS) based on MAS (w = 9%), with the addition of silicone DPS (MFS 3), on cotton and polyester fabrics, but advantage in stability when compared with other MFS investigated.     

数据驱动型实时燃烧优化控制架构及应用

在安全运行基础上,为提高火电机组经济性和环保性,提出了基于历史运行数据、燃烧试验数据和实时运行数据的燃烧优化自动控制架构。在该架构中引入稳态检测、锅炉效率在线计算、数据挖掘、非线性建模、智能优化等技术,得到用于燃烧优化的运行控制基准和实时控制增量指令。这些数据经过可靠的通信和安全无扰的控制逻辑与原控制系统进行融合,根据机组运行状态参与锅炉燃烧实时控制优化。基于该架构的燃烧优化系统已在燃煤电厂实际应用,在宽负荷范围内实现了燃烧运行状态分析、指令自动优化和锅炉效率提升。可基于该自动控制架构拓展优化其中各技术要素,并应用到其他各种炉型和控制系统中。     

CPU针脚修复小技巧

通常我们所说的硬件损伤主要包括软损伤和硬损伤,其中硬损伤是指由于各种原因对硬件直接造成的物理伤害,这样不仅会影响机器的正常使用,且新手对于修复一般会手足无措。或许提及维修,很多朋友都会望而却步,认为那是特别高深的事情。其实,很多常见故障维修都并不复杂,关键在于是否敢于动手。 我们首先谈谈CPU的常见故障,CPU的硬损伤一般是针脚损坏或     

Decentralized risk-sensitive controller design for strict-feedback systems

This paper studies decentralized control of uncertain systems. The class of systems focused on is a set of stochastic strict-feedback systems which interact through their outputs, and performance is measured with respect to a risk sensitive cost criterion. The unknown nonlinear interconnection terms are assumed to be bounded by some known functions of the outputs of the subsystems, multiplied by some unknown parameters. The controllers designed for each subsystem have access only to the information available with regard to the respective subsystem, and they achieve an arbitrarily small value for the risk-sensitive cost for the overall system. Under this completely decentralized control scheme, all closed-loop signals remain bounded in probability.     

Efficient Flow Computation on Massive Grid Terrain Datasets

As detailed terrain data becomes available, GIS terrain applications target larger geographic areas at finer resolutions. Processing the massive datasets involved in such applications presents significant challenges to GIS systems and demands algorithms that are optimized for both data movement and computation. In this paper we present efficient algorithms for flow routing on massive grid terrain datasets, extending our previous work on flow accumulation. Our algorithms are developed in the framework of external memory algorithms and use I/O-techniques to achieve efficiency. We have implemented the algorithms in the Terraflow system, which is the first comprehensive terrain flow software system designed and optimized for massive data. We compare the performance of Terraflow with that of state-of-the-art commercial and open-source GIS systems. On large terrains, Terraflow outperforms existing systems by a factor of 2 to 1,000, and is capable of solving problems no system was previously able to solve.     

Internal Oxidation of an Ag–1.3 at.% Te Alloy

The internal oxidation of Ag–1.3 at.% Te was studied at 750, 800, and 830°C in pure oxygen (1 atm). The internal oxidation under such high oxygen pressure resulted in formation of two different types of oxide particles and two different fronts of internal oxidation in the internal oxidation zone. The coarser Ag₂TeO₃ particles were formed through the in situ internal oxidation of Ag₂Te particles and the tiny oxide precipitates (most probably also Ag₂TeO₃) were formed through internal oxidation of tellurium from solid solution. Considering the mechanism of internal oxidation, both diffusionless and diffusive modes were found to be present simultaneously in the oxidation of Ag–1.3 at.% Te alloy. These results were examined with regard to the solubility of tellurium in silver, which was found to be 0.1 at.% Te at 750°C and 0.26 at.% Te at 830°C, as well as the presence and dissolution of Ag₂Te particles.     

基于机器视觉的滚抛磨块缺陷检测方法

为检测烧结型球状滚抛磨块的圆度和黑心缺陷,提出基于机器视觉的滚抛磨块缺陷检测方法。首先利用单片机、步进电机、采样圆盘、数字显微镜和上位机搭建磨块图像采集系统,实现磨块图像的连续采集;后利用图像灰度化、阈值分割、形态学处理提取磨块区域和黑心缺陷区域;再计算磨块区域的圆度和黑心缺陷尺寸;最后通过磨块缺陷检测试验确定磨块缺陷的检测阈值。结果表明:该方法能够对烧结型球状磨块的圆度和黑心缺陷进行数字化检测,分析磨块制备过程中存在的问题,为磨块制备方法改进提供反馈依据。      

Preparation and epoxy curing of p‐nonylphenol/dicyclopentadiene adducts

Phenol/dicyclopentadiene adducts were prepared from the BF₃‐catalyzed reaction of p‐nonylphenol and dicyclopentadiene at molar ratios of 2 : 1 and 3 : 2. These dicyclopentadiene‐derived novolac products contain tricyclodecane and multiple phenol functionalities. In curing with diglycidyl ether of bisphenol A, the polymer properties were compared with those cured with formaldehyde novolac or Jeffamine D‐400 amine. When p‐nonylphenol/dicyclopentadiene adducts were mixed with other commercially available curing agents such as Jeffamine D‐400 amine, the tricyclodecane functionality was introduced into the resulting epoxy network. The flexibility of the cured resin was improved due to the presence of the tricyclodecane moiety in the polymer structure. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2196–2206, 1999