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machine-vision-based electrode wear analysis for closed loop wire EDm process control

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Advances in manufacturing 2022年第1期10卷 131-142页

作者： p.m.Abhilash D.Chakradhar Department of mechanical Engineering Indian Institute of Technology PalakkadKerala 678557India

The purpose of this study was to develop a closed-loop machine vision system for wire electrical discharge machining(EDm)process *** wire wear leading to wire breakage is the primary cause of wire EDm process *** process interruptions are undesirable because they affect cost efficiency,surface quality,and process *** developed system monitors wire wear using an image-processing algorithm and suggests parametric changes according to the severity of the wire *** images of the wire electrode coming out from the machining zone are fed to the system as raw *** the proposed method,the images are preprocessed and enhanced to obtain a binary image that is used to compute the wire wear ratio(WWR).The input parameters that are adjusted to recover from the unstable conditions that cause excessive wire wear are pulse off time,servo voltage,and wire feed *** algorithm successfully predicted wire breakage *** addition,the alternative parametric settings proposed by the control algorithm were successful in reducing the wire wear to safe limits,thereby preventing wire breakage interruptions.

关键词： Wire electrical discharge machining(WEDm) machine vision Image processing Wire wear Wire electrode Wire breakage Inconel 718process control

ENERGY ESTImATES FOR DELAY DIFFUSION-REACTION EQUATIONS

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Journal of Computational mathematics 2008年第4期26卷 536-553页

作者： J.A.Ferreira p.m.daSilva CmUC-Departamento Departamento

In this paper we consider nonlinear delay diffusion-reaction equations with initial and Dirichlet boundary conditions. The behaviour and the stability of the solution of such initial boundary value problems （IBVps） are studied using the energy method. Simple numerical methods are considered for the computation of numerical approximations to the solution of the nonlinear IBVps. Using the discrete energy method we study the stability and convergence of the numerical approximations. Numerical experiments are carried out to illustrate our theoretical results.

关键词： Delay diffusion reaction equation Energy method Stability Convergence.

Far-infrared absorption studies of Be acceptors in δ-doped GaAs/AlAs multiple quantum wells

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Science China(physics,mechanics & Astronomy) 2006年第6期49卷 702-708页

作者： m. p. Halsall p. Harrison m. J. Steer School of physics and Astronomy the University of ManchesterManchester M60 1QD U. K. School of Electronic and Electrical Engineering University of LeedsLS2 9JT U. K. EpSRC Ⅲ-V Semiconductor Central Facility Department of Electronic and Electrical Engineering University of SheffieldS1 3JD U. K.

We report a far-infrared absorption study of internal transitions of shallow Be acceptors in both bulk GaAs and a series of δ-doped GaAs/AlAs multiple quantum well samples with well thicknesses of 20,15 and 10 nm. Low temperature far-infrared absorp-tion measurements clearly show three principal absorption lines due to transitions of Be-acceptor states from the ground state to the first three odd-parity excited states,respec-tively. Using a variational principle,the 2p-1s transition energies of quantum confined Be acceptors are calculated as a function of the well width. It is found that the theoretical calculation of the 2pz → 1s transitions is in good agreement with the D-like line experi-mental data.

关键词： shallow acceptor impurities,δ-doped,GaAs/AlAs multiple quantum wells,far-infrared absorptions.

Synergistic fibroblast optimization: a novel nature-inspired computing algorithm

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Frontiers of Information Technology & Electronic Engineering 2018年第7期19卷 815-833页

作者： T T DHIVYApRABHA p SUBASHINI m KRISHNAVENI Department of Computer Science Avinashilingam Institute for Home Science and Higher Education for Women

The evolutionary algorithm, a subset of computational intelligence techniques, is a generic population-based stochastic optimization algorithm which uses a mechanism motivated by biological concepts. Bio-inspired computing can implement successful optimization methods and adaptation approaches, which are inspired by the natural evolution and collective behavior observed in species, respectively. Although all the meta-heuristic algorithms have different inspirational sources, their objective is to find the optimum(minimum or maximum), which is problem-specific. We propose and evaluate a novel synergistic fibroblast optimization(SFO) algorithm, which exhibits the behavior of a fibroblast cellular organism in the dermal wound-healing process. Various characteristics of benchmark suites are applied to validate the robustness, reliability, generalization, and comprehensibility of SFO in diverse and complex situations. The encouraging results suggest that the collaborative and self-adaptive behaviors of fibroblasts have intellectually found the optimum solution with several different features that can improve the effectiveness of optimization strategies for solving non-linear complicated problems.

关键词： Synergistic fibroblast optimization (SFO) Fitness analysis Convergence Benchmark suite monk's dataset

The Influence of Seasonal Changes and Headwaters on physico-chemical Dynamics of Temengor Reservoir, malaysia

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湿地科学 2011年第4期9卷 314-321页

作者： Zarul Hazrin Hashim Asmah patiroi mashhor mansor Shahrul Anuar md. sah Donald C. Jackson School of Biological Sciences Universiti Sains Malaysia Department of Wildlife Fisheries and Aquaculture Mississippi State University

A study on physico-chemical dynamics of Temengor Reservoir was conducted to determine whether headwaters and seasonal changes play a major role in regulating physico-chemical dynamics of Temengor Reservoir. Temengor Reservoir receives water from its surrounding water catchments and headwaters. Then, the water flows into a series of hydroelectric dams, namely the Bersia, Kenering and Chenderoh dams. Generally, water quality in Temengor Reservoir can be classified as Class I. physico-chemical trends showed that water quality in euphotic zone of Temengor Reservoir is stable and consistent. Two-way ANOVA analyses showed that seasonal variations only affected water temperature, Secchi disc's depth and nitrate-nitrogen. Based on Tukey's post-hoc test, all three headwaters in this study exert no influence to the reservoir's water quality. These insignificant differences were probably due to water temperature and the size of the headwaters and the reservoir itself. In situ parameters profiling showed that the epilimnion zone in Temengor Reservoir is from the surface to 6 m depth, the metalimnion zone is from 6 m to 12 m depth and the hypolimnion zone is from 12 m depth onwards to the bottom of the reservoir. Thus, continuous water profiling monitoring that covers high and low water levels need to be conducted to determine characteristics of the physico-chemical dynamics in the water column and also to analyse changes in reservoir layers. Through these studies, discontinuity trends in the perak River could be determined and suggestions to the respective agencies could be made to conserve and to sustain downstream biodiversity.

关键词：湿地物理化学季节变化研究分析

A Spherical Relativistic Anisotropic Compact Star model

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International Journal of Astronomy and Astrophysics 2018年第1期8卷 46-67页

作者： prakash Chandra Fulara Archana sah Department of mathematics M B Govt. P G College Haldwani Nainital India

We provide solutions to Einsteins field equations for a model of a spherically symmetric anisotropic fluid distribution, relevant to the description of compact stars. The central matter-energy density, radial and tangential pressures, red shift and speed of sound are positive definite and are decreasing monotonically with increasing radial distance from the center of matter distribution of astrophysical object. The causality condition is satisfied for complete fluid distribution. The central value of anisotropy is zero and is increasing monotonically with increasing radial distance from the center of the distribution. The adiabatic index is increasing with increasing radius of spherical fluid distribution. The stability conditions in relativistic compact star are also discussed in our investigation. The solution is representing the realistic objects such as SAXJ1808.4-3658, HerX-1, 4U1538-52, LmC X-4, CenX-3, VelaX-1, pSRJ1614-2230 and pSRJ0348+0432 with suitable conditions.

关键词： Anisotropic Fluid Distribution Non Singular Solutions Einstein’s Field Equations Super Dense Star General Relativity

mHD effects on free convective flow over moving semi-infinite vertical cylinder with temperature oscillation

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Applied mathematics and mechanics(English Edition) 2011年第11期32卷 1367-1376页

作者： p.LOGANATHAN m.KANNAN p.GANESAN Department of mathematics Anna University Chennai Chennai 600025India Department of mathematics Anand Institute of Higher Technology KazhipatturChennai 603103India

Numerical solutions of magnetodynamics （mHD） effects on the free convective flow of an incompressible viscous fluid past a moving semi-infinite vertical cylinder with temperature oscillation are presented. The dimensionless, unsteady, non-linear, and coupled governing partial differential equations are solved by using an implicit finite difference method of the Crank-Nicolson type. The velocity, temperature, and concentration profiles are studied for various parameters. The local skin-friction, the average skinfriction, the Nusselt number, and the Sherwood number are also analyzed and presented graphically. The results are compared with available results in literature, and are found to be in good agreement.

关键词： free convection mHD finite difference method heat and mass transfer

Fashion and out of fashion:appearance and disappearance of a novel nest building innovation

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Avian Research 2017年第2期8卷 71-75页

作者： Anders p.møller Ecologie Systematique Evolution Universite Paris‑SudCNRSAgroParisTechUniversite Paris‑Saclay91405 Orsay CedexFrance

Background:Nests are composed of and built with different materials that are handled in specific ways. These mate?rials must initially have been used de novo before commonly being incorporated into nests. plastic and plastic bags were invented in the 1950s, and they are widely distributed in the environment. Birds started picking up plastic from plastic used to cover farm produce such as silage, potatoes, beets and other crops for use in their nests in the ***:I recorded the frequency of such plastic use by the Blackbird(Turdus merula) in nests in Denmark, starting in 1966, followed by a peak in use in the 1970s and a subsequent ***:Nests with plastic were initially built earlier in the season than those without plastic, indicating an associa?tion between innovation and early reproduction. plastic use was subsequently selected against because nests with plastic suffered from higher rates of predation than nests without plastic, probably because nests with plastic were easier to locate. However, the elevated risk of nest predation only applied to outdoor nests, but not to nests inside buildings, probably because visually searching nest predators such as corvids do not enter ***:These findings show that the dynamics of nest material use depend on the benefits of innovation and the fitness costs of nest predation.

关键词： Fashion Indoor breeding Innovation Nest predation Turdus merula

Comparison between the quality and function of sperm after semen processing with two different methods

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Asian Journal of Andrology 2001年第2期3卷 125-130页

作者： m.E.Hammadeh p.m.Zavos p.Rosenbaum W.Schmidt Dept. of Obs/Gyn University of Saarland 66421 Homburg/Saar GermanyAndrology Insitute of America and Kentucky Center for Reproductive Medicine & IVF Lexington KY USADept. of Obs/Gyn University of Saarland 66421 Homburg/Saar GermanyDept. of Obs/Gyn University of Saarland 66421 Homburg/Saar Germany

Aim: To compare the recovery rate of morphologically normal and chromatin condensed spermatozoa from native se-men samples using the Spermprep^(Tm) filtration columns and percoll gradient centrifugation and to determine the influenceof the two processing techniques on fertilization and pregnancy rates in an IVF-ET program. methods: Sixteen se-men samples obtained from patient's husband were included in this study. Each was divided into two aliquots. The firstaliquot was processed with Spermprep^(Tm) filtration columns and the second, percoll gradient centrifugation. Smears weremade before and after semen processing with both methods for the evaluation of chromatin condensation (chromomycineCmA3) as well as morphology (strict criteria) of spermatozoa. One hundred and seventy oocytes were retrieved fromthe patients and the oocytes from each patient were subdivided into two sets : one set was inseminated using spermatozoaprocessed with Spermprep^(Tm) and the other inseminated after semen processing with percoll gradient centrifugation. Re-sults: The percoll method yielded a significantly higher percentage of chromatin condensed (90.8 ±6.5% vs 82.3±8.8%, p = 0.017) and morphologically normal spermatozoa (12.9±7.4% vs 6.9±4.8%, p =0.001) in com-parison to Spermprep^(Tm). Whereas, sperm count recovery rate was significantly higher after the use of Spermprep^(Tm) thanafter the percoll gradient centrifugation. The fertilization rate was similar between the two methods. Conclusion:Semen processing with percoll should be recommended for intracytoplasmic sperm injection as the natural selection isbypassed and the Spermprep^(Tm) technique could be recommended for IVF and IUI programs as the sperm concentrationplays a more significant role in these procedures.

关键词： sperm semen processing spermprep^(Tm) percoll gradient centrifugation IVF