scholarly journals Hybrid Optimization Method for Correcting Synchronization Errors in Tapping Center Machines

2021 ◽  
Vol 11 (8) ◽  
pp. 3441
Author(s):  
Ping-Yueh Chang ◽  
Po-Yuan Yang ◽  
Shao-Hsien Chen ◽  
Jyh-Horng Chou
Keyword(s):  
Regression Analysis ◽  
Uniform Design ◽  
Regression Function ◽  
Cnc Machining ◽  
Numerical Control ◽  
Synchronization Errors ◽  
Parameter Combination ◽  
Uniform Dispersion ◽  
Best Parameter ◽  
Parameter Values

A hybrid method is proposed for optimizing rigid tapping parameters and reducing synchronization errors in Computer Numerical Control (CNC) machines. The proposed method integrates uniform design (UD), regression analysis, Taguchi method, and fractional-order particle swarm optimizer (FPSO) to optimize rigid tapping parameters. Rigid tapping parameters were laid out in a 28-level uniform layout for the experiments in this study. Since the UD method provided a layout with uniform dispersion in the experimental space, the UD method’s uniform layout provided iconic experimental points. Next, the 28-level uniform layout results and regression analysis results were used to obtain significant parameters and a regression function. To obtain the parameter values from the regression function, FPSO was selected because its diversity and algorithmic effectiveness are enhanced compared with PSO. The experimental results indicated that the proposed method could obtain suitable parameter values. The best parameter combination in FPSO yielded the best results in comparisons of the non-systematic method. Next, the best parameter combination was used to optimize actual CNC machining tools during the factory commissioning process. From the commissioning process perspective, the proposed method rapidly and accurately minimizes synchronization error from 23 pulses to 18 pulses and processing time from 20.8 s to 20 s. In conclusion, the proposed method reduced the time needed to tune factory parameters for CNC machining tools and increased machining precision and decreased synchronization errors.

Adaptive spiral tool path generation for computer numerical control machining using point cloud

2021 ◽  
pp. 095440622199007
Author(s):  
Mandeep Dhanda ◽  
Aman Kukreja ◽  
SS Pande
Keyword(s):  
Tool Path ◽  
Cnc Machining ◽  
Numerical Control ◽  
Numerical Control Machining ◽  
Form Errors ◽  
Spiral Tool Path ◽  
Novel Method ◽  
Mesh Grid ◽  
Cloud Of Points ◽  
Cam Software

This paper reports a novel method to generate adaptive spiral tool path for the CNC machining of complex sculptured surface represented in the form of cloud of points without the need for surface fitting. The algorithm initially uses uniform 2 D circular mesh-grid to compute the cutter location (CL) points by applying the tool inverse offset method (IOM). These CL points are refined adaptively till the surface form errors converge below the prescribed tolerance limits in both circumferential and radial directions. They are further refined to eliminate the redundancy in machining and generate optimum region wise tool path to minimize the tool lifts. The NC part programs generated by our algorithm were widely tested for different case studies using the commercial CNC simulator as well as by the actual machining trial. Finally, a comparative study was done between our developed system and the commercial CAM software. The results showed that our system is more efficient and robust in terms of the obtained surface quality, productivity, and memory requirement.

Perception of Terminal Fall Contours in Speech Produced by Deaf Persons

1990 ◽  
Vol 33 (1) ◽  
pp. 174-180 ◽  
Author(s):  
Judith Rubin-Spitz ◽  
Nancy S. McGarr
Keyword(s):  
Regression Analysis ◽  
Significant Contribution ◽  
Linear Regression Analysis ◽  
Regression Function ◽  
Multiple Linear Regression Analysis ◽  
Deaf Children ◽  
Relative Timing ◽  
Acoustic Measures ◽  
Final Syllable ◽  
Deaf Persons

Eight deaf children produced each of nine sentences. F 0 measures were obtained at several locations within each utterance (starting F 0 , peak F 0 , peak F 0 in the final syllable, and final F 0 ). The relative timing of each F 0 measure (ms from onset of the utterance) was also determined. In addition, several difference measures were derived. Listeners experienced with the speech of the deaf were asked to judge whether they heard a terminal fall, rise, or a flat final intonation contour in each utterance. A multiple linear regression analysis was used to determine if any combination of the acoustic measures could predict listeners’ responses. The only variable that made a significant contribution to the regression function was the temporal interval between the terminal peak F 0 and the final F 0 . That is, the more slowly the contour fell the more likely listeners were to perceive the contour as flat, regardless of the amount (in Hz or percentage F 0 ) by which it fell. The regression equation accounted for a statistically significant but not large proportion of the total variance. This suggests that other variables, not measured in this study, play an important role in the perception of utterance final intonation contours in the speech of the deaf.

scholarly journals A preliminary strategy for screening the combination of active components based on Bu–Shen–Yi–Qi Decoction for bronchial asthma

2019 ◽  
Vol 02 (03) ◽  
pp. 135-138
Author(s):  
Chen Yan ◽  
Qingli Luo ◽  
Cheng Ma ◽  
Jiaqi Liu ◽  
Jingcheng Dong
Keyword(s):  
Regression Analysis ◽  
Bronchial Asthma ◽  
Molecular Mechanisms ◽  
Uniform Design ◽  
Chinese Herbs ◽  
Chinese Drug ◽  
Active Components ◽  
Control Drug ◽  
Effective Components ◽  
Herba Epimedii

Objective: The anti-asthma herbal medicine Bu–Shen–Yi–Qi Decoction (BSYQ Decoction), a combination of three traditional Chinese medicine herbs developed in our lab, has shown demonstrated efficacy in Ovalbumin (OVA)-induced acute bronchial asthma. However, the obscure substances, multiple potential targets and the unclear molecular mechanisms are obstacles to control drug quality, stability and standardization. Multi-component formulae with a clear pharmacodynamic material and specific mechanism are an innovation worth exploring. They may also partly reserve a potential synergistic and additive effect compared with single components extracted from traditional Chinese herbs. This study was designed to select three standard multi-component formulae of the combination of effective components preliminarily based on four effective components [total flavonoids of Herba Epimedii ([Formula: see text]; Astragalus polysaccharide ([Formula: see text]; Astragaloside ([Formula: see text]; and Catalpol ([Formula: see text]] in BSYQ Decoction. Methods: OVA-induced asthmatic murine models were established. A uniform design was applied to select 10 proportions from four target components, and 3 formulae which showed best effect aimed at IFN-[Formula: see text], IL-4 and IgE in the serum respectively were screened based on stepwise regression analysis. Results: According to the regression analysis, Formula I ([Formula: see text]:[Formula: see text]:[Formula: see text]:6:29), Formula II ([Formula: see text]:[Formula: see text]:[Formula: see text]:8:2) and Formula III ([Formula: see text]:[Formula: see text]:[Formula: see text]:[Formula: see text]:50:8:2) are the three potential proper ratios for the new multi-component formula aimed at serum IFN-[Formula: see text], IL-4 and IgE in OVA-induced asthma mice, respectively. Conclusion: Three multi-component formulae derived from BSYQ Decoction could exert anti-inflammatory effect against OVA-induced asthma, which might provide evidences and lay foundations for further study of standard modern Chinese drug for treating asthma based on BSYQ Decoction.

Adaptive neuro-fuzzy fusion of multi-sensor data for monitoring of CNC machining

Sensor Review ◽  
2017 ◽  
Vol 37 (1) ◽  
pp. 78-81 ◽  
Author(s):  
Srdjan Jovic ◽  
Obrad Anicic ◽  
Milivoje Jovanovic
Keyword(s):  
Selection Process ◽  
Spindle Speed ◽  
Cnc Machining ◽  
Numerical Control ◽  
Periodic Component ◽  
Sensor Data ◽  
Depth Of Cut ◽  
Inference System ◽  
Content Type ◽  
Neuro Fuzzy

Purpose Acoustic emission (AE) could be used for prevention and detection of tool errors in Computer Numerical Control (CNC) machining. The purpose of this study is to analyze the AE form of CNC machining operations. Design/methodology/approach Experimental measurements were performed with three sensors on the CNC lathe to collect the data of the CNC machining. Adaptive neuro-fuzzy inference system (ANFIS) was applied for the fusion from the sensors’ signals to determine the strength of the signal periodic component among the sensors. Findings There were three inputs, namely, spindle speed, feed rate and depth of cut. ANFIS was also used to determine the inputs’ influence on the prediction of strength of the signal periodic component. Variable selection process was used to select the most dominant factors which affect the prediction of strength of the signal periodic component. Originality/value Results were shown that the spindle speed has the most dominant effect on the strength of the signal periodic component.

scholarly journals Parameter Selection in the Parameter Estimation of Grade Transitions in a Polyethylene Plant

2015 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Niklas Andersson ◽  
Per-Ola Larsson ◽  
Johan Åkesson ◽  
Niclas Carlsson ◽  
Staffan Skålén ◽  
...  
Keyword(s):  
Parameter Estimation ◽  
Steady State ◽  
State Parameter ◽  
Parameter Selection ◽  
Selection Algorithm ◽  
Parameter Estimations ◽  
Dynamic Case ◽  
Nominal Parameter ◽  
Best Parameter ◽  
Parameter Values

A polyethylene plant at Borealis AB is modelled in the Modelica language and considered for parameter estimations at grade transitions. Parameters have been estimated for both the steady-state and the dynamic case using the JModelica.org platform, which offers tools for steady-state parameter estimation and supports simulation with parameter sensitivies. The model contains 31 candidate parameters, giving a huge amount of possible parameter combinations. The best parameter sets have been chosen using a parameter-selection algorithm that identified parameter sets with poor numerical properties. The parameter-selection algorithm reduces the number of parameter sets that is necessary to explore. The steady-state differs from the dynamic case with respect to parameter selection. Validations of the parameter estimations in the dynamic case show a significant reduction in an objective value used to evaluate the quality of the solution from that of the nominal reference, where the nominal parameter values are used.

scholarly journals Comparison and Supervised Learning of Segmentation Methods Dedicated to Specular Microscope Images of Corneal Endothelium

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Yann Gavet ◽  
Jean-Charles Pinoli
Keyword(s):  
Image Segmentation ◽  
Cell Layer ◽  
Spatial Density ◽  
Specular Microscopy ◽  
Main Criterion ◽  
Segmentation Methods ◽  
Best Parameter ◽  
Good Transparency ◽  
Parameter Values

The cornea is the front of the eye. Its inner cell layer, called the endothelium, is important because it is closely related to the light transparency of the cornea. An in vivo observation of this layer is performed by using specular microscopy to evaluate the health of the cells: a high spatial density will result in a good transparency. Thus, the main criterion required by ophthalmologists is the cell density of the cornea endothelium, mainly obtained by an image segmentation process. Different methods can perform the image segmentation of these cells, and the three most performing methods are studied here. The question for the ophthalmologists is how to choose the best algorithm and to obtain the best possible results with it. This paper presents a methodology to compare these algorithms together. Moreover, by the way of geometric dissimilarity criteria, the algorithms are tuned up, and the best parameter values are thus proposed to the expert ophthalmologists.

Rethinking reverse logistics: role of additive manufacturing technology in metal remanufacturing

2019 ◽  
Vol 31 (1) ◽  
pp. 124-144 ◽  
Author(s):  
Danielle Strong ◽  
Michael Kay ◽  
Thomas Wakefield ◽  
Issariya Sirichakwal ◽  
Brett Conner ◽  
...  
Keyword(s):  
Supply Chain ◽  
Additive Manufacturing ◽  
Facility Location ◽  
Reverse Logistics ◽  
Small And Medium Enterprises ◽  
Real Data ◽  
Cnc Machining ◽  
Numerical Control ◽  
Content Type ◽  
The Usa

Purpose Although the adoption of metal additive manufacturing (AM) for production has continuously grown, in-house access to production grade metal AM systems for small and medium enterprises (SMEs) is a major challenge due to costs of acquiring metal AM systems, specifically powder bed fusion AM. On the other hand, AM technology in directed energy deposition (DED) has been evolving in both: processing capabilities and adaptable configuration for integration within existing traditional machines that are available in most SME manufacturing facilities, e.g. computer numerical control (CNC) machining centers. Integrating DED with conventional processes such as machining and grinding into Hybrid AM is well suited for remanufacturing of metal parts. The paper aims to discuss these issues. Design/methodology/approach Classical facility location models are employed to understand the effects of SMEs adopting DED systems to offer remanufacturing services. This study identifies strategically located counties in the USA to advance hybrid AM for reverse logistics using North American Industry Classification System (NAICS) data on geographical data, demand, fixed and transportation costs. A case study is also implemented to explore its implications on remanufacturing of high-value parts on the reverse logistics supply chain using an aerospace part and NAICS data on aircraft maintenance, repair and overhaul facilities. Findings The results identify the candidate counties, their allocations, allocated demand and total costs. Offering AM remanufacturing services to traditional manufacturers decreases costs for SMEs in the supply chain by minimizing expensive new part replacement. The hubs also benefit from hybrid AM to repair their own parts and tools. Originality/value This research provides a unique analysis on reverse logistics through hybrid AM focused on remanufacturing rather than manufacturing. Facility location using real data is used to obtain results and offers insights into integrating AM for often overlooked aspect of remanufacturing. The study shows that SMEs can participate in the evolving AM economy through remanufacturing services using significantly lower investment costs.

scholarly journals Design of an Axial Turbine for Highly Downsized Internal Combustion Engines

2020 ◽  
Vol 10 (17) ◽  
pp. 5935
Author(s):  
Lorenzo Baietta ◽  
Mamdouh Alshammari ◽  
Apostolos Pesyridis ◽  
Dhrumil Gohil
Keyword(s):  
Internal Combustion Engines ◽  
High Volume ◽  
Cnc Machining ◽  
Numerical Control ◽  
Driving Experience ◽  
Aspect Ratios ◽  
Efficient Reduction ◽  
High Volume Production ◽  
Axial Turbines ◽  
Efficient Power

This paper describes and discusses the development of an axial turbocharger turbine concept as a potential substitute to commercial radial turbines for high-volume production. As turbo-lag is one of the main issues related to the inertia of the rotating parts in a turbocharger, leading to less responsive and drive-cycle efficient power units, the use of axial turbines, with their inherently lower inertia than radial types for the same application, enables the efficient reduction of the spool-up time of the system, to the benefit of the driving experience and emissions. However, axial turbines for this application usually show complicated blades and level of twist, leading to efficient but expensive designs compared to their radial counterparts. Based on this challenge, the idea of comparing prismatic (generally less efficient, but cheaper) and twisted 3D-bladed axial turbines showed that for lower blade aspect ratios, the efficiency is of the same order. For these reasons, many turbines with a range of different sizes were designed with both layouts (3D and prismatic blades) and compared. Further, the use of 3D optical scanning, as well as dyno-calibrated 1D engine models enabled the gathering of invaluable data to design the proposed solution and compare it to the Original Equipment Manufacturer (OEM) version. Thanks to these processes, the comparison between the proposed design and the OEM one was not limited to the performance, and also included the manufacturing costs, which were calculated via Computer Aided Manufacturing (CAM) programs, with the limitation of using only Computer Numerical Control (CNC) machining for production. To conclude, the work showed a notable performance superiority of the proposed turbine in respect to the OEM one, despite a slightly higher estimated production cost.

scholarly journals ECC Design Based on Uniform Design Test Method and Alternating Conditional Expectation

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Xiaoqin Li ◽  
Xiao Yang ◽  
Zude Ding ◽  
Xi Du ◽  
Jincheng Wen
Keyword(s):  
Regression Analysis ◽  
Conditional Expectation ◽  
Raw Materials ◽  
Uniform Design ◽  
Test Method ◽  
High Fracture ◽  
Four Point Bending ◽  
Alternating Conditional Expectation ◽  
Mix Proportion ◽  
Tensile Strains

Engineered cementitious composites (ECC) have higher ultimate tensile strains than normal concrete. The mechanical properties of ECC strongly depend on raw materials and the mix proportions. The uniform design test method and alternating conditional expectation, which is a nonparametric regression analysis method, were used to design the ECC mix proportion. According to the regression analysis, the optimized W/B, S/B, and F/B ranges could be obtained as 0.35–0.42, 0.25–0.3, and 0.02, respectively. The tested proportions for validation were randomly adopted within the range of W/B, S/B, and F/B. The uniaxial compression, tension, and four-point bending tests were conducted to verify the material behaviour of the designed ECC. Results showed that all the specimens had large ultimate tensile strains and high fracture energy capacities, and strain hardening was also observed. The fibers were found to be uniformly distributed in the specimens by using a scanning electron microscope. This paper may provide theoretical and practical guidance for the ECC and other cement-based material mix proportion design.

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