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To develop lightweight and high-strength curved beetle elytron plates (CBEPs), an algorithm to extract a cross-section point set based on three-dimensional point cloud data measured from a beetle forewing and to reconstruct its outer surface was designed. This approach was used to study three beetle species. The curve fitting method and the curvature distribution characteristics of the corresponding forewings during the reconstruction were investigated. (1) Two algorithms, namely, the median surface separation method and segmented microstrip method, were established. (2) Two types of fitting methods were proposed: judging the consistency of the curvature curve peaks to determine higher-degree polynomials (clusters) and implementing k-fold cross-validation to determine the optimal engineering fitting curve. The optimal fitting curves for the cross-section point sets of the various beetle forewings involved in this paper were discovered to be elliptic equations. (3) The curvature characteristics of the forewing cross-sections vary depending on the type of fitting curve used; accordingly, researchers can choose the most appropriate fitting curve. For the research and development of CBEPs, elliptic equations can be used to establish the required bionic structure model, the important structural parameters of which include not only the long and short axes of the ellipse but also the position and length of the segment. This paper, therefore, lays a foundation for the development of CBEPs. [ABSTRACT FROM AUTHOR]

In order to optimize the indoor lighting effect and reduce the energy consumption of indoor lighting, the light source layout of conventional rooms and special rooms is studied in this paper. Firstly, the indoor space lighting model is analyzed, and the expressions of light source output and illumination on the target plane are derived. Secondly, in order to improve the search ability of the algorithm in specific areas, combined with the artificial bee colony algorithm, an improved artificial bee colony algorithm suitable for indoor lighting optimization is proposed. Using the average square difference of the illuminance of the target plane as the adaptation function, a penalty function is introduced, and the minimum circle surrounding strategy is used to search the specific location of the light source. Finally, the obtained layout is fitted by engineering standardization, and the indoor light source layout is obtained. Through the simulation of illuminance effect in conventional room and irregular room, it is proved that the proposed method can effectively improve the lighting effect and reduce the energy consumption of indoor lighting under the same number of light sources and the same illuminance index. [ABSTRACT FROM AUTHOR]

Probability distributions have prominent applications in different sectors. Among these sectors, probability models are mostly used to analyze datasets in engineering. Among the existing probability distributions, the two-parameter Weibull model plays an important role in providing the best fit for engineering and other related datasets. This paper introduces a new method called a novel updated-W (denoted by "NU-W") family of distributions that is used to develop a new updated form of the Weibull distribution. The proposed updated extension of the Weibull model is referred to as a novel updated Weibull (denoted as NU-Weibull) distribution. Distributional properties such as identifiability, heavy-tailed characteristic, and rth moment of the NU-W family are derived. The residual life analysis of the NU-Weibull distribution is provided. Finally, two physical applications from civil engineering and reliability sectors are analyzed to demonstrate the application and effectiveness of the NU-Weibull distribution. The data fitting results show that the NU-Weibull distribution is a more suitable and best fit for engineering datasets. [ABSTRACT FROM AUTHOR]

In this paper, we suggest a brand new extension of the inverse Lomax distribution for fitting engineering time data. The newly developed distribution, termed the transmuted Topp–Leone inverse Lomax (TTLILo) distribution, is characterized by an additional shape and transmuted parameters. It is critical to notice that the skewness, kurtosis, and tail weights of the distribution are strongly influenced by these additional characteristics of the extra parameters. The TTLILo model is capable of producing right-skewed, J-shaped, uni-modal, and reversed-J-shaped densities. The proposed model's statistical characteristics, including the moments, entropy values, stochastic ordering, stress-strength model, incomplete moments, and quantile function, are examined. Moreover, characterization based on two truncated moments is offered. Using Bayesian and non-Bayesian estimating techniques, we estimate the distribution parameters of the suggested distribution. The bootstrap procedure, approximation, and Bayesian credibility are the three forms of confidence intervals that have been created. A simulation study is used to assess the efficiency of the estimated parameters. The TTLILo model is then put to the test by being applied to actual engineering datasets, demonstrating that it offers a good match when compared to alternative models. Two applications based on real engineering datasets are taken into consideration: one on the failure times of airplane air conditioning systems and the other on the active repair times of airborne communication transceivers. Also, we consider the problem of estimating the stress-strength parameter R = P (Z 2 < Z 1) with engineering application. [ABSTRACT FROM AUTHOR]

This paper aims to deepen the understanding of elderly consumers' grocery shopping practices during Covid-19. Drawing on the shopping-as-practice approach within social practice theory, we show how the practices unfold as the pandemic evolves and the situation of the elderly change, which implies new possibilities and limitations in grocery shopping. Qualitative telephone interviews with elderly consumers were conducted in 2020 and followed up during 2021. By analysing the elderly's grocery shopping as a social practice, we show how different modes of shopping practices (in-store, online and assisted shopping), came about, how they were reconfigured, and what made them work smoothly or not during the corona pandemic. We also show how the grocery shopping practices, and the modes involved were situated and synchronised in everyday life. The paper also discusses the implication for retailers. [ABSTRACT FROM AUTHOR]

In order to improve fitting accuracy of grey forecasting model according to the function transformation theory and grey system modeling theory, DGM(1,1) model based on anti-cotangent function for a non-negative ascending sequence is built in this paper. And DGM(1,1) model based on variable speed translation anti-cotangent function transformation for a non-negative oscillating sequence is built in this paper. For a non-negative ascending sequence, it has been proved that the smooth ratio, stepwise ratio deviation, and stepwise ratio variance after the function transformation can be reduced effectively. The function transformation methods in this paper are used in setting up models for ascending and oscillating sequences and the calculation results of actual examples show that the function transformation proposed in this paper is valid to an extent. [ABSTRACT FROM AUTHOR]

This paper demonstrates the need for and provides an improved fitting of the line parameters when a wide range of frequencies with emphasis on the dc response is the objective. The improved fitting is based on a low-order fitting of a function error for each of the line parameters, that is, the characteristic admittance and propagation function, in the low-frequency range. The function error represents the difference between the analytical evaluation of the line parameters, that is, obtained from a frequency-dependent distributed parameters line model, and their initial rational approximation, for example, given by an electromagnetic transients software tool. The approximated function error, added to the initial rational approximation of the line parameters, provides the enhanced fitted line model. The enhanced fitting improves the dc response of the line and ensures numerical stability in time-domain simulations. This paper applies the proposed fitting approach to the universal line model for time-domain simulations. The simulation results by the enhanced fitting are validated by comparing the results with those obtained from a frequency-domain line model (FDLM). Two case studies are presented to illustrate the proposed fitting approach. [ABSTRACT FROM AUTHOR]

Globally, women are a minority in the engineering profession. Various initiatives are adopted by employers to support women's career progression and retention in the profession. This paper examines the effectiveness of the common initiatives. Focus groups were conducted with 25 New Zealand based female engineers to explore their experiences and perceptions of women in engineering initiatives. Women discussed the effectiveness, and unintended consequences, of the initiatives. Their responses were coded using the NVivo software to identify key themes, which were then categorized using the universal/selective/indicated model. The findings show that universal initiatives which encompass men and women are well supported with few unintended consequences. These initiatives (e.g., subconscious bias training) focus less on changing or supporting women and more on changing the environment. In contrast, selective initiatives (e.g., female leadership programs) which focus on women, had mixed support and more unintended consequences. Specifically, they emphasize societal stereotypes that men are a better fit for the role of engineer and that women need help to adapt to the male-dominated environment. This study concludes with recommendations for employers to implement that will increase the participation and advancement of women in engineering. [ABSTRACT FROM AUTHOR]

In this paper, nanosheet deformation during channel release has been investigated and discussed in Gate-All-Around (GAA) transistors. Structures with different source/drain size and stacked Si nanosheet lengths were designed and fabricated. The experiment of channel release showed that the stress caused serious deformation to suspended nanosheets. With the guidance of the experiment result, based on simulation studies using the COMSOL Multiphysics and Sentaurus tools, it is confirmed that the stress applied on the channel from source/drain plays an important role in nanosheet deformation during the fabrication process. The deformation of Si nanosheets would cause a serious degradation of the device performance due to an inability to control the work function of the metal gate. This study proposed that the uniformly stacked GAA nanosheets structure could be successfully demonstrated with suitable channel stress engineering provided by fitting S/D size and an appropriate channel length. The conclusions provide useful guidelines for future stacked GAA transistors' design and fabrication. [ABSTRACT FROM AUTHOR]

In the metal cutting industry, manufacturers have strived to increase energy efficiency and to reduce environmental burdens through the use of dust collectors and waste disposers. It is more beneficial and efficient to apply the front-of-pipe technology that prevents the sources of pollutants and minimises energy use through the redesign of products and the change of process planning and machining operations. In particular, process planning for the environment, called eco-process planning, is central to increasing energy efficiency and reducing environmental burdens because process planning decisions greatly influence machining performance. At present, greenability, a term used to indicate environmental friendliness, has been little considered as a major concern in the process planning stage because process planning decisions have focused on improving productivity aspects that include speed, cost and quality. Thus, it is essential to develop an eco-process planning approach that enables the harmonisation and enhancement of greenability performance while improving productivity performance, termed green productivity (GP). This paper presents the development of a GP-based process planning algorithm that enables the derivation of process parameters for improving GP in machining operations. The core mechanism of the algorithm is the realisation of the process improvement cycle that measures GP performance by the collection of machining data, quantifies this performance by categorical representation and predicts the performance through prediction models. To show the feasibility and applicability of the proposed algorithm, we have conducted an experiment and implemented a prototype system for a turning machining process. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has greatly impacted consumer food shopping. This paper aims to conceptualise, illustrate and explain how and why online grocery shopping has changed during the pandemic. Taking a shopping-as-practice approach and drawing on ethnographic interviews with 31 Swedish households, we analyse how online grocery shopping was performed during the pandemic. Our findings show that online grocery shopping was reinvented during the pandemic, it was no longer only a convenient mode of shopping, but became also a way to cope with the crisis brought about by Covid-19. This change, however, was demanding as developing and routinizing a new mode of shopping practice required substantial work on the part of consumers. Consumers had to engage in detailed planning, to learn to shop anew, and to develop temporal sensitivity. By developing this new mode of online grocery shopping consumers were able to cope, both practically and emotionally, with the challenges brought on by the restrictions. This study provides insights into consumers' capacities to manage a food crisis, showing that this capacity depends on both retailers' digital food platforms as well as consumers' pre-existing shopping competencies and social networks. We conclude by discussing both the managerial and societal implications of these results. [ABSTRACT FROM AUTHOR]

Machining process is usually needed to fettle the assembly interfaces of large-scale component before the final assembly. There are several issues that make the process time and effort consuming, such as hard-to-machine material, difficulties in positioning and alignment, errors between as-built component, and as-designed model. Shop floor optimization is essential for machining this kind of large and complex workpiece but is limited by information loss from CAD/CAM to CNC (Computer Numerical Control) using traditional G&M codes. STEP-NC has been proven to perform excellently in data exchange between CAD/CAM and CNC but it does not support some special processes in machining the assembly interfaces. To solve these matters, this paper proposes a closed-loop machining system based on extended STEP-NC data models which cover aligning and laser tracker measuring process. The system consists of: (1) a STEP-NC compliant CAD/CAM system which exports STEP-NC programs, (2) a STEP-NC high-level process controller which translates STEP-NC programs and makes closed-loop optimization, and (3) CNCs and mechanical systems which perform machining and measuring tasks. In the end, a vertical tail of a large passenger plane is used as a study case to demonstrate the advantages of the proposed data models and systems. This paper contributes to machining the assembly interfaces of large-scale components, and the future development of STEP-NC in large-scale manufacturing. [ABSTRACT FROM AUTHOR]

Indian traditional architectural practice 'Vastusastra' (Vāstuśāstra) recommends some particular ratios as auspicious for the proportioning of domestic buildings. Similar ratios are found in some ancient buildings belonging to the classical ages in other parts of the world. Recent studies conducted by Dhileep, Kottuppillil, and Kurian [2019. "Orientation and Proportion in Indian Traditional Domestic Architecture." Interdisciplinary Science Reviews 44 (1): 97–109], show that the square and the rectangle formed by the basic auspicious ratio (breadth:length) are geometrically related to a circle with a diameter equal to the length of the rectangle. The mathematical aspects behind these geometrical relationships and other ratio groups given in 'Vastusastra' (Vāstuśāstra) are investigated in this paper. The study reveals that the auspicious ratios help to convert the area of a circle to a rectangle and vice versa, without any loss in accuracy, while using the methods of their age. The traditional social practices are incorporated into these ratios and are modified adequately to fit into the traditional engineering practice. [ABSTRACT FROM AUTHOR]

Copyright of Perspectivas Contemporâneas is the property of Perspectivas Contemporaneas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, the weight functions for multiple axial cracks in a coated hollow cylinder have been investigated. The stress intensity factors (SIFs) for two reference loading cases were computed via the finite element method, which was then used to derive the weight functions. Dimensional analysis was carried out to reveal the dependence of dimensionless weight function on various important quantities such as normalized crack depth, crack spacing, and material constants. The results of such parameters dependence were presented in graphical forms and were eventually expressed by an empirical formula through a decoupled fitting method. Comparison was made on the SIF determination by the derived weight function and by other methods in literature, and an excellent agreement was found. The derived weight functions are expected to facilitate SIF calculation for a coated hollow cylinder with multiple axial cracks. [ABSTRACT FROM AUTHOR]

Chatter is a kind of self-excited, unstable vibration in almost all machining processes. Existing studies have been focusing on the pre-chatter stage, developing various techniques to detect, predict, and suppress chatter. In real applications, chatter will inevitably happen under certain cutting conditions, with generating chatter marks on the workpiece surface. Additional operations are required to remove chatter marks before the finish machining. It is noted that chatter marks will easily induce chatter again, resulting in worse surface quality. This paper quantitatively analyzes the effects of chatter marks on the stability of the process by modeling chatter marks with a periodically modulated depth of cut. Stability lobes show that the existence of chatter marks greatly reduces the stability limit. Furthermore, chatter mark removal using spindle speed variation (SSV) is proposed. Extended high-order full-discretization method using Lagrange interpolation is developed to analyze the effect of SSV on chatter marks removal. It is shown that SSV can remarkably improve the stability limit even with chatter marks. Finally, machining experiments of thin-walled discs are conducted to verify the deterioration effect of chatter marks on the stability limit and show that chatter marks can be effectively removed by the SSV. [ABSTRACT FROM AUTHOR]

Copyright of Tourism Review is the property of Emerald Publishing Limited and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Machining accuracy is a very important index to measure the performance of NC machine tools, and how to improve the machining accuracy grabs the attention of both manufacturers and users. Since the geometric errors are intercoupling and are one of the main factors affecting machining accuracy of machine tools, in this paper, a new method for extracting key geometric errors based on the screw theory and extended Fourier amplitude sensitivity test (EFAST) method was proposed. First, screw theory was introduced, and the machining accuracy modeling of a three-axis vertical machining center (VMC) was established. Then, in order to analyze the coupling effects between geometric errors by high-dimensional nonlinear model, EFAST global sensitivity analysis method was adopted to help in extracting the main geometric errors. An illustration example on a three-axis VMC shows that the proposed method is effective and can be helpful to improve the geometric accuracy of machine tool. [ABSTRACT FROM AUTHOR]

A rational determination of machining parameters of electrical discharge machining (EDM) is of vital importance to the machining quality. This paper proposes an ANSYS emulation, experimental correction, and numerical fitting method (AEN-XRD method) to determine the relationship between machining parameters and machining indicators of various kinds of machine tools. Firstly, it adopts ANSYS software to make simulation researches of the pit size with different electrical parameters. Theoretical calculation of corresponding machining indicators is presented. Based on the machine data, adjustment is made on the simulation outcome. And thereby, based on the adjusted outcome, numerical fitting method is adopted to determine the functional relation formula of machining parameters and machining indicators. Experiments of different machine tools have shown that there is a relatively high prediction accuracy of machining parameters and they are capable to meet the actual machining demand, which further proves the AEN-XRD method is of great practicability. [ABSTRACT FROM AUTHOR]

This paper focusses on the supermarket shopper, who makes both reflexive and routine decisions while undertaking his or her regular shopping and cooking practices. The research used narrative inquiry methodology and convenience sampling to gather stories about a group of supermarket shoppers' perceptions of, and engagement with their chosen food retail environment and their attitudes towards making more sustainable food choices. The analysis drew on theories of practice and a food choice model showing that this group of shoppers were aware of the challenges of the modern food system and held ideals about purchasing Australian-grown, ethically produced food, eating seasonally and devoting more time to shopping and cooking, but the intangible resource of time dominated their dynamic value negotiations. [ABSTRACT FROM AUTHOR]

This paper describes the experiment of measuring the temperature and cutting force during the drilling of short holes without using cutting lubricants, at constant cutting speed, and at increasing shift . Measurement was performed on steel samples of grade 11 523. During drilling, temperature was monitored by a thermocouple, using the method of two foreign metals. Cutting force was measured by a strain-gauge sensor. The experiment provides a quick orientation in the given issue and points out to the optimisation of cutting conditions. Based on results, it can be stated that the range of temperatures and the size of cutting forces depends on technological conditions, cutting parameters, and mechanical and physical properties of tool and workpiece's material. [ABSTRACT FROM AUTHOR]

In this paper a novel approach is proposed to investigate the characteristics of the plasma channel and material removal in electrochemical discharge machining (ECDM) of glass. For this purpose, a specific pulsed voltage was applied to the ECDM process to perform single discharging on the glass workpiece. In this way, a voltage slightly lower than the critical voltage was applied as the offset voltage. Meanwhile the working voltages above the critical voltage were applied to the process in a specific period of time to produce single sparks. The signatures of the single sparks on the workpiece surface were used to determine the characteristics of the plasma channel. According to the results, the average diameter of 260 µm was achieved for the plasma channel in the glass machining conditions. This paper also reports a thermophysical model for material removal in ECDM process based on the finite element method (FEM) and plasma channel diameter achieved in this study. The amount of the removed material as well as the diameter and depth of the crater, achieved by the FEM, was measured and compared with the experimental outcomes. The results demonstrate the consistency of the proposed model with the experimental observations. [ABSTRACT FROM PUBLISHER]

For high-value added products, machining tools' lifespan significantly influences the quantity of procurement in machining process. Preemption of tools from the workpiece while processing is continuing is sometime beneficial to safeguard the product from the damage due to tool failure or its malfunction. Also an early discard of a tool is costly for the manufacturing operation. Therefore an optimal strategy for the tool life is sought here to determine the maximum allowable tool lifespan to preempt from the workpiece and to have an appropriate amount of tool stock in the crib to ascertain the proper running of the production schedule and tool inventory. Therefore, an impact of the machining tool lifespan on the production-inventory policy of the system is investigated in this paper. An integrated lifespan related inventory model for machining tools is developed to meet the responding accurate requirement of procurement and inventory. Two numerical examples are presented to illustrate the integrated model. The results show that the practical lifespan adoption of machining tools has significant impact on the whole quantity of procurement, and eventually influences the coordinating economic decision making. [ABSTRACT FROM AUTHOR]

Based on the rate-dependent non-aging constitutive model and the rate-independent aging constitutive model, a rate-dependent aging constitutive model is proposed to explain the changes in mechanical properties of ethylene propylene diene monomer (EPDM) rubber under different strain rates and aging states. In order to simulate the actual use state of rubber, accelerated aging tests are conducted on the samples in a hot air aging environment. The grey wolf algorithm is utilized to accurately fit the engineering stress–strain curve obtained from the experiment, obtaining specific coefficient values that represent the effects of strain rate, aging time, and aging temperature in the constitutive model. The results confirm the effectiveness of the proposed rate-dependent aging constitutive model in accurately predicting the mechanical property changes of EPDM rubber under different strain rates and aging states. The consistency between the experimental data and the calculated results is within the acceptable error range. It is worth noting that the stress in the model shows the dependence on strain rate, aging time and aging temperature, emphasizing the mechanical property changes of EPDM rubber at high temperatures and low strain rates simulated in the uniaxial tensile state. [ABSTRACT FROM AUTHOR]

Nowadays, the issue of predicting soil settlement has gradually become an important research area. The theory of predicting soil settlement under static load is comparatively mature, while the method of predicting soil settlement under dynamic loading is still at the exploratory stage. This paper aimed to find a suitable model to satisfy the prediction of long-term settlements of subway tunnel. The settlement monitoring data of Subway Line 1 in Shanghai were taken as the case. In this paper, current nonlinear prediction methods of settlement were summarized. The fitting method was introduced and applied in the settlement data of Shanghai subway tunnel; correlation coefficient r of the fitting results can keep a high level in most cases, illustrating the validity of segmentation simulation. Two kinds of prediction methods and its utilizing methods were introduced in this paper, i.e., Grey Model (1, 1) and Auto-Regressive and Moving Average Model ( n, m). The settlement trend of Subway Line 1 in Shanghai was predicted by GM (1, 1) and ARMA ( n, m) model. The results show that ARMA ( n, m) model is more precise than the GM (1, 1). As a new method in settlement prediction field, ARMA ( n, m) model is prospective in the future. [ABSTRACT FROM AUTHOR]

A new hybrid fuzzy-Artificial Bee Colony algorithm (Fuzzy-ABC) for the optimization of electrochemical machining (ECM) process parameters is presented in this paper. The 6061Al/10%wt Al2O3/5%wt SiC composite is taken as a test specimen and its machining characteristics on ECM process are studied. Maximizing the material removal rate (MRR), minimizing the surface roughness (Ra) and minimizing the over-cut (OC) are the main indicators of quality of an ECM process and thus are considered as objectives. The main process parameters governing the ECM process are current, applied voltage, flow rate, tool feed rate, inter-electrode gap and electrolyte concentration. The central composite design of response surface methodology was employed in order to identify the effective machining parameters on the above objectives. Fuzzy Logic (FL) concepts provide a fairly accurate prediction, when sufficient information is not available. The artificial bee colony (ABC) algorithm is a new evolutionary computational technique provides better results to that of other algorithms. Hence, in this paper, fuzzy logic was integrated with artificial bee colony algorithm, thus making a new hybrid Fuzzy-ABC algorithm. The optimized values for ECM were obtained through the hybrid Fuzzy-ABC algorithm. Confirmatory experiments reveal that the experimental values are fairly close with optimized values. [ABSTRACT FROM AUTHOR]

Owing to their superior mechanical, physical, and chemical characteristics, titanium and its alloys are broadly used in different industrial applications such as military, aerospace, power generation, and automotive. However, titanium alloys are inherently difficult to cut materials due to the high generated temperature during machining. In addition to flood cooling, several other techniques were employed to reduce the harmful effect and the generated temperature and generally improve titanium alloys machinability. In this paper, an attempt is made to utilize nano-additives to improve the cooling efficiency of minimum quantity lubrication (MQL) during machining titanium alloys. The main objective of the current research is to investigate the influence of dispersed multi-walled carbon nanotubes (MWCNTs) into vegetable oil by implementing the MQL technique during turning of Ti-6Al-4V. The novelty here lies on enhancing the MQL heat capacity using different concentrations of nano-fluid in order to improve Ti-6Al-4V machinability. Different cutting tests were performed and relevant data were collected. The studied design variables were cutting speed, feed rate, and percentage of added nano-additives (wt%). It was found that 2 wt% MWCNT nano-fluid reduced the power consumption by 11.5% in comparison with tests performed without any nano-additives, while the same concentration reduced the flank wear by 45%. [ABSTRACT FROM AUTHOR]

The bridge influence line (IL) is widely used in structural evaluation, damage identification, model updating, and other applications. The IL curve of an existing bridge is usually different from its designed value. It is crucial, yet challenging, to detect the actual bridge IL by measurement. In this paper, a fitting method is proposed for extracting the bridge IL from the dynamic response induced by a passing vehicle. Based on the theoretical mechanism of bridge IL under different boundary conditions, along with the features of bridge vibration, a piecewise polynomial and a series of harmonic sinusoids are established to describe the IL of the measured point and the fluctuation part of the bridge response, respectively. A mixed function obtained by linear superposition of these factors is utilized to fit the bridge dynamic response. The coefficients of the piecewise polynomial can be extracted by a least-square calculation; and subsequently, the actual IL curve of the measure point of the bridge is obtained. Numerical examples of vehicle-bridge models are adopted to validate the fitting method of IL extraction proposed in this paper, and to illustrate the efficiency by comparing it with the existing direct inverse calculation method. The validity and feasibility of this method are also demonstrated by both a laboratory experiment and a field test. [ABSTRACT FROM AUTHOR]

In this paper, we present a recent evolution of the analytical form of the Gogny force. The extension of the density-dependent term to a finite range is discussed and has led to the D2 Gogny force. A global refitting of the force has been done but preserving standard good properties of the Gogny force. Indeed the same fitting procedure with the same constraints and filters which have been used to obtain the D1-type parametrizations has been applied. The evolution of global properties (binding energies and nuclear radii) along the N = 8, 20, 28, 40 isotopic chains is discussed at the Hartree-Fock-Bogoliubov approximation level. Results coming from systematic calculations based on 1385 nuclei are also presented. Axial symmetry has been assumed. A comparison with the results obtained using the D1S parametrization, which tends to show that the D2 and the D1S Gogny force display very similar axial deformation properties, is done. [ABSTRACT FROM AUTHOR]

To study the impact of cutting blasting on the surface, a vibration waveform prediction function was constructed, and a method of dividing the affected area was proposed. Based on the equivalent spherical charge theory, it is possible to establish a connection between the fitting coefficient and the engineering parameters in the equivalent source intensity function. Furthermore, a blasting vibration waveform function suitable for engineering can be constructed. Secondly, the reliability of the method introduced is verified through the data monitored on-site. Finally, the affected partitions of blasting vibration are divided based on the peak particle velocity and vibration displacement as standards. The results show that the vibration waveform prediction system introduced can restore the vibration waveform corresponding to cutting blasting. In addition, the zoning method can reasonably divide the scope of the affected area. [ABSTRACT FROM AUTHOR]

Large taper (≥ ± 5°) high-speed wire electrical discharge machining can be affected by many factors. The positioning error of wire electrode caused by guide wheels and the run-out of guide wheels are particularly important. Moreover, dielectric fluid cannot wrap the wire electrode appropriately and flow into the machining region along with the wire electrode in tilt directions. As a result, the machining accuracy and surface roughness of a large taper-cutting workpiece are worse than those of straight cutting. In order to solve these problems, this paper presents the design and improvement of two types of six-bar linkage large taper-cutting mechanisms that can realize the guide of wire electrode and the tracking spray of dielectric fluid along with the incline of the wire electrode. The first type causes angular error but no wear, whereas the second one causes wear but no angular error. The former is applied to process experiments. The experimental results show that, compared with traditional mechanisms, this new approach decreases the roundness error of the workpiece from 80 to 40 μm and the surface roughness from 4.059 to 3.495 μm under the same processing parameters. In terms of multi cutting (skim cutting), the new mechanism reduces the roundness error of taper cutting (taper ±20°, thickness 40 mm) to 25 μm and the surface roughness to 1.670 μm. An idea of intelligent servo traverse guider based on this mechanism is also proposed in this study. [ABSTRACT FROM AUTHOR]

Cleaner production and sustainability are of crucial importance in the field of machining processes where great amount of energy is being consumed. This paper outlines the application of gray relational theory in order to optimize the machining parameters for Ti6Al4V in high-speed dry electrical discharge milling (EDM) using a tubular graphite electrode. The objective of optimization is to achieve simultaneously the minimum power consumption and the maximum material removal rate (MRR). The maximum MRR 5634 mm/min was obtained with a power consumption of 7.61 kW. MRR stayed in the similar level, and power consumption was reduced by 17.82 % compared with that of the parameters in our previous study. Current is the main effect factor on MRR and power consumption. The corresponding single pulsed experiments were conducted to deeply explore the reasons for the influence of air pressure and electrode rotation speed on the MRR and power consumption. [ABSTRACT FROM AUTHOR]

An efficient machining is limited by the chatter of machining system including spindle and support, which would cause poor surface quality. This paper proposed an improved stability prediction method based on the dynamics of machine tool. Dynamics of the support are considered into the stability prediction of machining process. The spindle was modeled by the receptance coupling substructure analysis method to predict the dynamics at the tool point. The mathematical model of the closed manufacturing system (machine tool, spindle, holder, and tool) was given, as well as the details of joint contacts. The model was used to obtain the system characteristics, and the FRFs of the tool point were obtained from the model in frequency domain. Moreover, the stability limitation for machining system were developed to create the stability lobe diagram with the FRFs of both the spindle and support. Experimental results showed that the depths of improved stability lobes were smaller than those of the original ones, and the improved lobes were more accurate for the stability predictions. The machined surface quality showed that the stable machining system was beneficial to produce good surface. This improved method is helpful for the stability calculation and machining parameter selection especially when milling a thin-walled workpiece or a weak clamping fixture. [ABSTRACT FROM AUTHOR]

Titanium alloy TB6 is often used to produce key load carrying parts in the aviation and aerospace industries. The superior mechanical properties pose challenges to machining processes, bringing about such problems as rapid tool wear. In this paper, fine-grain WC/Co tools were utilized in dry turning of the TB6 alloy. The wear modes and wear mechanisms of the cutting tools at different cutting speeds were detailed. The analysis showed that the wear on the tool rake face was characterized as crater formation. The principal wear mode observed on the tool flank face appeared to be microchipping near the region of the cutting edge. The adhesion was more pronounced on the rake face than on the flank face. The clusters of WC particles were pulled out from the Co binder along the grain boundaries, which led to adhesive wear and left an intergranular fractured surface. The crater wear was a result of the elements of the cutting tool diffusing into the adhering material, which was carried away by the flowing chip, leading to a transgranular dissolution of the WC particles, and the worn surface was smooth. The chemical reaction possibly took place at the tool/adhering material interface, where the newly formed compounds were carried away by the flowing chip. The hard particles that adhered to the back surface of the titanium chip probably abrade the tool surface, causing abrasive wear. [ABSTRACT FROM AUTHOR]

The purpose of these papers is to minimize the importance of technology, ignoring its basic role in constructing technical products can lead to a substantial increase in the workload and the consumption of material necessary for their manufacture and consequently to the increase in the costs for their manufacture. As regards the design activity, it is necessary to automate the main stages, which are: conceptual design, analysis and technological design. It is noteworthy that the analysis part is an integral part of the design process. Even if the analysis cannot fully replace the prototype experimental test, it can help the designer develop an optimized prototype. [ABSTRACT FROM AUTHOR]

With the present paper, the author proposes a fitting method for approximating experimental data retrieved from any full-field technique. Unlike most of the fitting procedures, the method works on data distributed on a surface of any shape, and the mathematical model is able to take into account of both the 3D shape of the surface and of the experimental quantity to be fitted. The paper reports all the mathematical steps necessary for applying the method, which was tested on two sets of experimental data obtained by an out-of-plane speckle interferometer working in two different conditions of noise. Experimental results showed the capability of the method to work in presence of high level of noise. [ABSTRACT FROM AUTHOR]

In the previous work, a machining robot based on an industrial robot was developed for foamed polystyrene materials. A robotic CAM system was incorporated in the robot to realize teachingless operation. In this paper, a fuzzy reasoning method processing radius of curvature is designed to skilfully regulate endmill's feed rate. The basic design of the machining robot using the fuzzy feed rate controller is presented for foamed polystyrene materials. Further, it is demonstrated that the mapping obtained by the fuzzy feed rate controller is well replaced by a multi-layered neural network. [ABSTRACT FROM AUTHOR]

Fixtures are the work-holding devices, widely used in manufacturing, to completely immobilize the workpiece during machining. The position of fixture elements around the workpiece strongly influences the workpiece deformation which in-turn affects the machining accuracy. The workpiece deformation can be minimized by finding the appropriate position for the locators and clamps. Thus, it is necessary to model the complex behavioral relationship that exists in the fixture–workpiece system. In this research paper, response surface methodology is used to model the relationship between position of locators and clamps and maximum deformation of the workpiece during end-milling, and then the developed model has been optimized by genetic algorithm and particle swarm optimization. As the predictive model is being developed by response surface methodology, a huge reduction in computational complexity and time is achieved during the optimization of machining fixture layout. Also, it is evident that the approach which integrates response surface methodology and particle swam optimization produces better results. [ABSTRACT FROM AUTHOR]

There are many disadvantages affecting the accuracy of surface topography measurement and analysis. One of them are the errors obtained during data processing. Usually surface topographies of car engine parts are studied after form removal. Many algorithms and procedures were developed and suggested. However, the selection of reference plane with accordance to surface topography measurements of cylindrical elements was not fully recognized. In this paper least square fitting methods (cylinder, polynomial) and commercial filters (Gaussian filter, Gaussian regression filter and robust Gaussian regression filter) for areal form removal were compared and proposed. Three types of surfaces: cylinder liners after plateau-honing, plateau-honed cylinder liners with oil pockets created by burnishing techniques and turned piston skirts were analyzed. Distortion of surface topography parameters (from ISO 25178 standard) according to improper selection of reference plane was also taken into consideration. It was assumed that least squares fitted cylinder plane gave better results for both of type cylinder liners according to commonly used algorithm. However, for piston skirt surfaces the obtained results were very similar. For least squares polynomial fittings it was found that applied method for cylinder liners gave usually better robustness for scratches, valleys and dimples occurrence. For piston skirt surfaces better edgefiltering results were obtained. It was also recommended to analyse the Sk parameters for proper selection of reference plane in surface topography measurements. [ABSTRACT FROM AUTHOR]

This paper presents a new approach of tool wear compensation based on “volume removal per discharge” (VRD) in “reverse-micro-electrical-discharge machining.” In this process, a plate with predrilled microhole is used as a tool, the erosion of which limits the fabrication of desired height of microrod(s). Therefore, in order to achieve the dimensional accuracy of this microrod(s), such tool plate wear needs to be compensated. Since this approach is based on the real-time estimation of volume removal from workpiece, which is obtained by multiplying the number of “contributing” pulses with VRD, an accurate estimation of VRD is very much essential for availing correct tool wear compensation. In this work, VRD is estimated by considering two new aspects: the number of actual “contributing” pulses and the variation of VRD with machining depth. These pulses are identified by a “pulse discriminating” system developed in house. The real-time material removal volume from workpiece is then used to estimate the “real-time height” of microrods after considering the over cut and taperness of each microrod. The proposed method is also compared with the normal machining method and “uniform wear method” and found to be more accurate with a negligible error of maximum 1.7%. [ABSTRACT FROM PUBLISHER]

In manufacturing shops in practice, machine capacity is often constrained by more than one type of resource. Yet research mainly focusses on the effects of only one type of resource that constrains machine capacity, e.g. labour, tooling or auxiliary constraints. In response, we use simulation to assess the impact of order release, dispatching and resource assignment rules in make-to-order job shops with multiple resource constraints. The capacity wasted while a machine stands idle waiting for other resources increases with the number of constraints, and all three production planning and control functions have little impact on this waiting time. Effective production planning and control can however improve operational performance in terms of time and tardiness-related measures. In general, combining order release control with a dispatching rule that prioritises jobs for which all resources are available at dispatching and a longest queue resource assignment rule leads to the best performance. Most importantly, and rather counterintuitively, prioritising orders with the fewest missing resources worsens the performance of both the dispatching and resource assignment rule since it reduces resource utilisation during periods of high load. Results from dual resource-constrained shops are consequently not directly transferable to more complex resource-constrained shops. [ABSTRACT FROM AUTHOR]

This paper addresses the compensation of cutting process related errors in order to improve the accuracy of manufactured parts. The compensation is a modification of the tool dimension and the tool path using on-machine probing data. A cutting depth distribution-based approach is proposed to calibrate the cutting process according to the on-machine probed error model. This approach is investigated in cases of both rigid and compliant parts. The calibration offset is estimated for the actual cutting conditions with and without a fitting process. In the case study, the offset varies from 12 to 17 μm for down milling at 6000 rpm spindle speed. The impact of the cutting speed is investigated. A rectangular profile was machined with and without compensation in down and up milling mode. The results show that the proposed approach is effective. The error is reduced from a maximum of 25 μm for down milling and 10 μm for up milling to 4 μm in both cases. [ABSTRACT FROM AUTHOR]

We analyzed the principle of the traditional local binary fitting operation, Gaussian kernel function weighted summation (GKFWS), to develop a novel level set model in this paper. In this model, the traditional GKFWS operation is replaced with the median filter operation in the second procedure of local fitting of the energy domain. Furthermore, we incorporated the edge stopping function of GAC model into it to introduce the edge information for segmentation. Experiments on synthetic and real images demonstrate that this model has promising performance in terms of computational cost, robustness to noises and segmentation of images with intensity inhomogeneity. [ABSTRACT FROM AUTHOR]

Most manufacturing shops in practice have limited physical space in front of each workstation, due, for example, to physical, economical or operational constraints. As a result, a job may cause blocking because it has to remain at a given station after an operation has been completed until space in front of the next station in its routing becomes available. Despite this practical reality, the Workload Control literature typically assumes infinite buffer limits and therefore neglects the impact of blocking. Using simulation, we highlight the direct, detrimental impact of blocking in both the pure and general flow shop. Workload Control order release dampens the effect of blocking and improves overall performance. This makes Workload Control order release even more important in the context of shops with blocking or physical space constraints. Further analysis reveals that the impact of blocking is less pronounced in the pure flow shop given its directed routing. Finally, most of the blocking that occurs is because jobs cannot enter the shop, i.e. there is no space in front of the gateway station. This re-emphasises the close relationship between blocking and release methods that limit the workload, and it highlights the importance of workload balancing. [ABSTRACT FROM AUTHOR]

Abstract Automatically modeling and intelligently monitoring composite tunnel structures is of great significance considering the development of composite and diverse tunnel construction materials. Therefore, how to efficiently analyze the deformation of all kinds of tunnel structures with its expanding application is becoming increasingly important. In this paper, we analyze the over- and under-fitting problems under different point cloud profiles to generate an automatic and robust B-spline model which is a suitable method for high accuracy approximation capable of optimizing the composite tunnel model by adjusting the parameters. The innovation of this research is that we combine the maximum likelihood function and the degree of freedom to obtain the optimal parameters model of composite tunnels, which are validated by the various profiles. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Sintering thermal state was proposed to be jointly described by TRP, BRP and BTP. • Feature points was extracted via piecewise fitting and time series-based approach. • Evaluation model was established based on random forest algorithm. • Soft-measuring models can identify and classify the interior thermal state exactly. • Automatic control system can enhance stable control and reduce energy consumption. Abstract Thermal state of iron ore sintering in iron and steel production cannot be revealed straightforward, which is unfavorable for field operations. In this paper, the soft-measuring models were established to extract the feature points through curve fitting method and evaluate the whole state via random forest algorithm. All the models proposed were validated by the industrial data, and the results show that feature extraction model can identify the variation of reaction zones, and evaluation model possesses a classification accuracy over 95%. The soft-measuring models were integrated into the automatic control system developed for sintering plant. Running results illustrate that the system can enhance the stable control and reduce the power consumption of sintering process. [ABSTRACT FROM AUTHOR]

Ultra-high precision measuring machines enable to measure aspheric shapes with an uncertainty of few tens of nanometres. The resulting clouds of points are then associated to theoretical model at the same level of accuracy so as to obtain parameters that indicate about form error. Minimum zone ( MZ ), defined as the least value of peak to valley ( PV ), is widely used to assess form error. Least squares method (L 2 ) is often used to determine MZ but the resulting value is usually overestimated. For this reason, L 2 is replaced by L ∞ norm because it gives a more accurate value of MZ since it directly minimizes PV . Using L ∞ norm results in a non-smooth optimization problem and consequently its resolution becomes more challenging compared to L 2 . In this paper, a novel minimax fitting method for accurate metrology of aspheres and freeform based on a hybrid trust region algorithm (HTR) is proposed. To assess performance of the introduced method, it was compared to an available minimax fitting algorithm based on a smoothing technique: exponential penalty function (EPF). The choice of EPF is justified by superior performances in comparison to existing techniques. Comparison was conducted on reference data, data available in literature and data gathered form measurements of a real optical high quality asphere. Results show superiority of HTR over EPF in both returned PV values and execution time. [ABSTRACT FROM AUTHOR]

Most shops in practice are constrained by more than one resource. Consequently, a large body of literature on dual resource constrained shops has emerged. This research typically focuses on worker assignment rules, with attention being on when and where to move workers. In contrast, the decision concerning who to reallocate to a station has received limited attention. The limited prior work assumes workers are assigned to a new station as soon as they become available or seeks to minimise the risk of worker idleness. Using simulation, we question this assumption and show that it can be beneficial to introduce additional worker idleness to ensure workers only work at their most efficient station(s). In general, it is less likely that there are several workers available for one station than it is for there to be multiple stations available for one worker. Consequently, the Who Rule is used less frequently than the Where rule and has less of an impact on performance. Finally, considering the criticality of work orders as part of the Where Rule is important in assembly shops; but if labour is heterogeneous then the focus should be on efficiency. The findings have important implications for research and practice. [ABSTRACT FROM AUTHOR]