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Influence of Various Parameters on Collapse Behaviour of Thin Cylinders

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上海交通大学学报 2004年第z2期38卷 1-7页

作者： N K gupta Applied Mechanics Department ⅡT Delhi India - 110016

Axial compression experiments on as received aluminum tubes and tubes with wall thickness eccentricity incorporated by off centre machining showed that the eccentricity caused transition of their collapse mode from axisymmetric to diamond. The numerical simulation of the collapse phenomenon was undertaken using a static non-linear Finite Element Analysis in ANSYS, and results are found to compare well with the experimental load compression and energy absorption responses for axisymmetric concertina and non-axisymmetric diamond modes. Having validated the numerical model with experiments, it has been used to undertake a systematic study of the load - compression characteristics and collapse mode transitions of the tubes with varying eccentricities in wall thickness and boundary conditions, as well as the material properties.

关键词： thin tube collapse thickness eccentricity ANSYS axial compression

Active Learning Query Strategies for Classification,Regression,and Clustering:A Survey

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Journal of Computer Science & Technology 2020年第4期35卷 913-945页

作者： Punit Kumar Atul gupta Indian Institute of Information Technology Design and ManufacturingJabalpurMadhya Pradesh 482005India

Generally,data is available abundantly in unlabeled form,and its annotation requires some *** labeling,as well as learning cost,can be minimized by learning with the minimum labeled data *** learning(AL),learns from a few labeled data instances with the additional facility of querying the labels of instances from an expert annotator or *** active learner uses an instance selection strategy for selecting those critical query instances,which reduce the generalization error as fast as *** process results in a refined training dataset,which helps in minimizing the overall *** key to the success of AL is query strategies that select the candidate query instances and help the learner in learning a valid *** survey reviews AL query strategies for classification,regression,and clustering under the pool-based AL *** query strategies under classification are further divided into:informative-based,representative-based,informative-and representative-based,and ***,more advanced query strategies based on reinforcement learning and deep learning,along with query strategies under the realistic environment setting,are *** a rigorous mathematical analysis of AL strategies,this work presents a comparative analysis of these ***,implementation guide,applications,and challenges of AL are discussed.

关键词： active learning active learning query strategy active classification active regression active clustering deep active learning

Linear and nonlinear propagation characteristics of multi-Gaussian laser beams

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Chinese Physics B 2020年第11期29卷 370-379页

作者： Naveen gupta Sandeep Kumar Lovely Professional University PhagwaraIndia

Theoretical investigation on the propagation characteristics of a new class of laser beams known as multi Gaussian(M.G)laser beams has been *** investigate the linear characteristics,propagation of the laser beam in vacuum has been ***,the nonlinear characteristics have been investigated in *** nonlinearity of the plasma has been modeled by relativistic mass nonlinearity of the plasma electrons in the field of laser *** is based on finding the semi analytical solution of the wave equation for the slowly varying envelope of the laser ***,the dynamical evolutions of the beam width and longitudinal phase of the laser beam have been investigated in detail.

关键词： self-focusing multi Gaussian self phase modulation self-channeling

Constraining Galactic pγ Interactions with Cosmic Ray Electron and Positron Spectra

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Chinese Journal of Astronomy and Astrophysics 2008年第2期8卷 153-158页

作者： Nayantara gupta Department of Physics University of Nevada Las Vegas

High energy protons produced by various sources of cosmic rays, e.g., supernova remnants, pulsar wind nebulae, active galactic nuclei and gamma-ray bursts, participate in pγ and pp interactions. Although pp interactions may be the dominant mechanism in our Galaxy, it is unclear how important Pγ process is. We show that the upper bound on the fraction of total number of protons participating in pγ interactions inside all Galactic astrophysical sources of cosmic rays is 10%.

关键词： Cosmic rays protons, electrons, positrons

On Bounded Variation Functions by General MKZD Operators

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Acta Mathematica Sinica,English Series 2007年第8期23卷 1457-1462页

作者： Vijay gupta School of Applied Sciences Netaji Subhas Institute of TechnologyAzad Hind Fauj MarySector 3 Dwarka New Delhi-110075India

In this paper, we study the rate of convergence for functions of bounded variation for the recently introduced Bzier variant of the Meyer-Knig-Zeller-Durrmeyer operators.

关键词： approximation by positive operators rate of convergence degree of approximation functions of bounded variation total variation

Predicting Code Smells and Analysis of Predictions: Using Machine Learning Techniques and Software Metrics

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Journal of Computer Science & Technology 2020年第6期35卷 1428-1445页

作者： Mohammad YMhawish Manjari gupta Computer Science Centre for Interdisciplinary Mathematical SciencesInstitute of ScienceBanaras Hindu University Varanasi 221005India

Code smell detection is essential to improve software quality, enhancing software maintainability, and decrease the risk of faults and failures in the software system. In this paper, we proposed a code smell prediction approach based on machine learning techniques and software metrics. The local interpretable model-agnostic explanations (LIME) algorithm was further used to explain the machine learning model's predictions and interpretability. The datasets obtained from Fontana et al. were reformed and used to build binary-label and multi-label datasets. The results of 10-fold cross-validation show that the performance of tree-based algorithms (mainly Random Forest) is higher compared with kernel-based and network-based algorithms. The genetic algorithm based feature selection methods enhance the accuracy of these machine learning algorithms by selecting the most relevant features in each dataset. Moreover, the parameter optimization techniques based on the grid search algorithm significantly enhance the accuracy of all these algorithms. Finally, machine learning techniques have high potential in predicting the code smells, which contribute to detect these smells and enhance the software's quality.

关键词： code smell code smell detection feature selection prediction explanation parameter optimization

Determining the relationship between chemical composition and size, shape and effective density of airborne fine particles through concurrent use of inertial and optical based measurements

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Particuology 2016年第5期14卷 93-101页

作者： Anand Kumar Tarun gupta Environmental Engineering and Management Program Indian Institute of Technology Kanpur Kanpur 208016 India Institute of Atmospheric and Climate Science Swiss Federal Institute of Technology Zurich Zurich 8092 Switzerland Department of Civil Engineering Indian Institute of Technology Kanpur Kanpur 208016 India

This study presents the development of a medium flow, multiple slit based PM2.5 （particle aerodynamic diameter 〈2.5 μm） inertial impactor. Its performance was compared with that of a light scattering based optical particle sizer in a field study and in controlled lab based experiments using polydisperse dolomite powder as test aerosol. The impactor＇s optimum nozzle configuration had a cutoff size of 2.51 μm （aero- dynamic diameter） at an operating flow rate of 215 L/rain with a pressure drop of 0.35 kPa across the impactor stage. Because the apparent particle density of an ambient aerosol depends on the physical properties and the chemical composition of the particles, the PM2.5 mass concentration was measured with an optical particle sizer and an inertial impactor over a weekday and a weekend day in a field study during which the effective particle shape factor and density were in tandem modified in order to com- pare the results from the two sampling techniques. The correlation of the two instrument results tended towards 1：1 with increasing values of shape factor （irregular shaped） and effective particle density. This observation was supported through chemical investigations of the collected mass, which showed a higher percentage contribution from elements which are mostly of crustal nature （namely, Ca, Fe, and Mg）.

关键词： lmpactor PM2.5 Optical particle counter Effective particle density Shape factor

Uniqueness,reciprocity theorem,and plane waves in thermoelastic diffusion with a fractional order derivative

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Chinese Physics B 2013年第7期22卷 286-297页

作者： Rajneesh Kumar Vandana gupta Department of Mathematics Kurukshetra University

In this work, a theory of thermoelasticity with diffusion is taken into consideration by using the methodology of fractional calculus. The governing equations for particle motion in a homogeneous anisotropic fractional order generalized thermoelastic diffusive medium are presented. Uniqueness and reciprocity theorems are proved. The plane wave propagation in the homogeneous transversely isotropic thermoelastic diffusive medium with fractional order derivative is studied. For the two-dimensional problem, there exist a quasi-longitudinal wave, a quasi-transverse wave, a quasi-mass diffusion wave, and a quasi-thermal wave. From the obtained results, the different characteristics of waves, like phase velocity, attenuation coefficient, specific loss, and penetration depth, are computed numerically and presented graphically. Some special cases are also discussed.

关键词： thermoelastic diffusion fractional calculus uniqueness theorem reciprocity theorem

On dry machining of AZ31B magnesium alloy using textured cutting tool inserts

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Journal of Magnesium and Alloys 2024年第4期12卷 1608-1618页

作者： Shailendra Pawanr Kapil gupta Department of Mechanical and Industrial Engineering Technology University of JohannesburgDoornfontein CampusJohannesburg 2028 South Africa

Magnesium alloys have many advantages as lightweight materials for engineering applications,especially in the fields of automotive and *** undergo extensive cutting or machining while making products out of *** cutting,a sustainable machining method,causes more friction and adhesion at the tool-chip *** of the promising solutions to this problem is cutting tool surface texturing,which can reduce tool wear and friction in dry cutting and improve machining *** paper aims to investigate the impact of dimple textures(made on the flank face of cutting inserts)on tool wear and chip morphology in the dry machining of AZ31B magnesium *** results show that the cutting speed was the most significant factor affecting tool flank wear,followed by feed rate and cutting *** tool wear mechanism was examined using scanning electron microscope(SEM)images and energy dispersive X-ray spectroscopy(EDS)analysis reports,which showed that at low cutting speed,the main wear mechanism was abrasion,while at high speed,it was *** chips are discontinuous at low cutting speeds,while continuous at high cutting *** dimple textured flank face cutting tools facilitate the dry machining of AZ31B magnesium alloy and contribute to ecological benefits.

关键词： Magnesium alloy Dry machining Textured tools Flank wear Sustainability