Unsupervised author disambiguation using Dempster–Shafer theory

The name ambiguity problem presents many challenges for scholar finding, citation analysis and other related research fields. To attack this issue, various disambiguation methods combined with separate disambiguation features have been put forward. In this paper, we offer an unsupervised Dempster–Shafer theory (DST) based hierarchical agglomerative clustering algorithm for author disambiguation tasks. Distinct from existing methods, we exploit the DST in combination with Shannon’s entropy to fuse various disambiguation features and come up with a more reliable candidate pair of clusters for amalgamation in each iteration of clustering. Also, some solutions to determine the convergence condition of the clustering process are proposed. Depending on experiments, our method outperforms three unsupervised models, and achieves comparable performances to a supervised model, while does not prescribe any hand-labelled training data.     

Through-thickness strength measurements using Arcan’s method

This paper presents results obtained from the experimental study on the behaviour of glass/epoxy butterfly-shaped specimens tested under pure shear and biaxial loadings using an Arcan device. Notch-to-notch longitudinally and perpendicularly oriented fibre specimens, respectively referred to as Mat31 and Mat32 ones have been tested with different loading angles ranging from 0° to 90°. The fracture mode was more or less repetitive for Mat31 specimens whereas it depended on the loading direction for Mat32 type, for which the number of cracks and the obliqueness relative to the notch-to-notch line, decreased as the test angle increased. The comparison of failure envelopes has demonstrated that Mat31 specimens are much more resistant whatever the loading angle. However, strengths at failure of Mat32 type are in good agreement with Hashin’s failure criterion, for pure shear tests up to 30° loading angles. Mat31 specimens’ failure stresses were overestimated by the criterion, although similarities in trends were noticed.     

Toughening of epoxy using core–shell particles

An epoxy resin, cured using an anhydride hardener, has been modified by the addition of preformed core–shell rubber (CSR) particles which were approximately 100 or 300 nm in diameter. The glass transition temperature, T _g, of the cured epoxy polymer was 145 °C. Microscopy showed that the CSR particles were well dispersed through the epoxy matrix. The Young’s modulus and tensile strength were reduced, and the glass transition temperature of the epoxy was unchanged by the addition of the CSR particles. The fracture energy increased from 77 J/m² for the unmodified epoxy to 840 J/m² for the epoxy with 15 wt% of 100-nm diameter CSR particles. The measured fracture energies were compared to those using a similar amount of carboxyl-terminated butadiene-acrylonitrile (CTBN) rubber. The CTBN particles provided a larger toughening effect when compared to CSR particles, but reduced the glass transition temperature of the epoxy. For the CSR-modified epoxies, the toughening mechanisms were identified using scanning electron microscopy of the fracture surfaces. Debonding of the cores of the CSR particles from the shells was observed, accompanied by plastic void growth of the epoxy and shell. The observed mechanisms of shear band yielding and plastic void growth were modelled using the Hsieh et al. approach (J Mater Sci 45:1193–1210). Excellent agreement between the experimental and the predicted fracture energies was found. This analysis showed that the major toughening mechanism, responsible for 80–90% of the increase in fracture energy, was the plastic void growth.     

Agility evaluation using the IF–THEN approach

The recent trend in the manufacturing sector is to develop highly customised products to satisfy niche needs of customers. In order to satisfy this requirement, a newer manufacturing technique has been deployed; this is called Agile Manufacturing (AM). AM principles are used to manufacture highly customised products within a shorter period of time. In this article, the IF–THEN rules approach has been used to evaluate the current agile position of the firm. The assessment has been carried out in an Indian modular switches manufacturing company. The assessment revealed that the organisation is fairly agile. Besides computing agility level, the gaps that impede agility have been identified, and proposals for agility improvement have been derived. The identified proposals are subjected to implementation in the case organisation.     

Desulphurization during VIM Refining Ni-base Superalloy using CaO Crucible

The variation of S content during VIM refining Ni-base superalloy using CaO crucible was studied. It was foundthat the desulphurization process could not be carried out by only using CaO crucible. The role of Al additionto desulphurization was also studied. Combining with the results of XRD and composition analysis of the CaOcrucible, the mechanism of desulphurization was proposed. Thermodynamical calculation about the reaction betweenthe interface of CaO crucible and liquid metal has been discussed. This work indicated that under proper refiningtechnology the S content in the liquid Ni-base alloy could be reduced from 3×10-5 to 2×10-6~4×10-6.     

Joint image compression–encryption using discrete fractional transforms

Exchange of data in the form of text and image on internet is in fast progression and it is spawning new compression and encryption algorithms for bandwidth and security respectively. We have proposed a new kind of joint algorithm using discrete fractional transforms for compression–encryption of image. In this algorithm, the discrete fractional Fourier transform which is discrete version of fractional Fourier transform, is used to compress the images with variation of its parameter ‘α’ (order of transform). The compressed image is encrypted using discrete fractional cosine transform to provide security. The advantage of this method is its feasible implementation in practice, superior, robustness, security and sensitivity of keys, which has a good prospect and practicability in information security field. Results of computer simulations are presented to verify the validity of the proposed method such as mean square error (MSE) and peak signal to noise ratio between the original image and decrypted image. Sensitivity for right decryption key is proved with respect to MSE.     

Manipulation and tracking of superparamagnetic nanoparticles using MRI

The use of magnetic fields in magnetic resonance imaging (MRI) for the tracking and delivery of chemotherapeutics bound to superparamagnetic nanoparticles offers a promising method for the non-invasive treatment of inoperable tumours. Here we demonstrate that superparamagnetic magnetite nanoparticles fabricated by an easily scalable method can be driven and tracked in real time at high velocities in vitro using MRI hardware. Force balance calculations are consistent with the magnetic properties of individual 10 nm diameter particles that move collectively as micron sized agglomerates with hydrodynamic diameter similar to that inferred from zero-magnetic-field dynamic light scattering measurements.     

Spatially resolved phase objects using Mach–Zehnder interferometry

Phase characterization with a good spatial resolution is crucial for focused beams in nonlinear media. The phase-shifting interferometry technique, using the least-squares error criterion for several interferograms, is implemented using a reflective spatial light modulator (SLM). The method provides a convenient calibration for any phase-shift steps. The reliability of the proposed method is checked by direct comparison with results obtained by the Fourier transform method as well as using a previously characterized circular phase object.     

Simultaneous multidimensional deformation measurements using digital holographic moiré

This paper proposes an elegant technique for the simultaneous measurement of in-plane and out-of-plane displacements of a deformed object in digital holographic interferometry. The measurement relies on simultaneously illuminating the object from multiple directions and using a single reference beam to interfere with the scattered object beams on the CCD plane. Numerical reconstruction provides the complex object wave-fields or complex amplitudes corresponding to prior and postdeformation states of the object. These complex amplitudes are used to generate the complex reconstructed interference field whose real part constitutes a moiré interference fringe pattern. Moiré fringes encode information about multiple phases which are extracted by introducing a spatial carrier in one of the object beams and subsequently using a Fourier transform operation. The information about the in-plane and out-of-plane displacements is then ascertained from the estimated multiple phases using sensitivity vectors of the optical configuration.     

Flexibility-based structural damage identification using Gauss–Newton method

Structural damage will change the dynamic characteristics, including natural frequencies, modal shapes, damping ratios and modal flexibility matrix of the structure. Modal flexibility matrix is a function of natural frequencies and mode shapes and can be used for structural damage detection and health monitoring. In this paper, experimental modal flexibility matrix is obtained from the first few lower measured natural frequencies and incomplete modal shapes. The optimization problem is then constructed by minimizing Frobenius norm of the change of flexibility matrix. Gauss–Newton method is used to solve the optimization problem, where the sensitivity of flexibility matrix with respect to structural parameters is calculated iteratively by only using the first few lower modes. The optimal solution corresponds to structural parameters which can be used to identify damage sites and extent. Numerical results show that flexibility-based method can be successfully applied to identify the damage elements and is robust to measurement noise.     

Development of nanocrystalline Fe–Co alloys using mechanical alloying

Abstract

Nanostructured alloys have considerable potential as soft magnetic materials. In these materials a small magnetic anisotropy is desired, which necessitates the choice of cubic crystalline phases of Fe, Co, Ni, etc. In the present work, Fe–50 at.-%Co alloys were prepared using mechanical alloying (MA) in a planetary ball mill under a controlled environment. The influence of milling parameters on the crystallinity and crystal size in the alloys was studied. The particle size and morphology were also investigated using SEM. In addition, a thermal treatment was employed for partial sintering of some of the MA powders. The crystal size in both MA powders and compacted samples was measured using X-ray diffraction. It was shown that the crystal size could be reduced to less than 15 nm in these alloys. The nanocrystalline material obtained was also evaluated for magnetic behaviour.     

Resolved CFD–DEM coupling simulation using Volume Penalisation method

A resolved CFD–DEM coupling model for the simulation of particulate flows is proposed in this work. The Volume Penalisation (VP) method, which is a family of the continuous forcing Immersed Boundary (IB) method, is employed to express the particle–fluid interaction. A smooth mask function is used to avoid sharp transition between the solid (particle) and fluid domains that may cause numerical oscillation with moving particles. Optimal permeability is employed to reduce the model error associated with the VP method. It is determined as a function of only the interface thickness and fluid kinematic viscosity. The proposed model is accurate, easy to implement with any discretisation scheme, and only requires small computational overhead for particle–fluid interaction. Several simulations are performed to test the validity of the proposed model in various systems, i.e. from dilute to relatively dense flows, and the results show good agreement with the exact solution or empirical correlation. It is found that the error can be scaled with the ratio between the gap and interface thickness. The proposed model is also applied to predict the relative viscosity of suspensions and the density segregation in fluidised beds.     

Investigation of glass–ionomer cements using differential scanning calorimetry

Six commercial glass–ionomer cements commonly used for various dental applications have been investigated using differential scanning calorimetry (DSC). The heat-flow behaviour and heat capacity of the cements were measured during isothermal (at 37°C) setting reactions. The DSC results show that all materials undergo an exothermic setting process, but with different enthalpies of reactions and different heat capacities; there are no remaining endo- or exothermic reactions after the setting of the cement. All materials examined were found to be effective thermal insulators.     

Statistical tolerance analysis using the unified Jacobian–Torsor model

This paper presents the results of ongoing research aimed at developing an integrated computer-aided tolerancing tool. A unified Jacobian–Torsor approach has been developed for deterministic (worst case) computer-aided tolerancing. The paper describes how one can use the same set of interval-based deterministic equations in a statistical context. The nature of the resulting equations lends itself to very fast computations to determine the percentage of rejected assemblies produced given some statistical distribution of the tolerances of their constituent parts. An example application is also presented to illustrate the use of the developed tool.     

Reconstruction of complex signals using minimum Rényi information

An information divergence, such as Shannon mutual information, measures the distance between two probability-density functions (or images). A wide class of such measures, called α divergences, with desirable properties such as convexity over all space, was defined by Amari. Rényi's information Dα is an α divergence. Because of its convexity property, the minimum of Dα is easily attained. Minimization accomplishes minimum distance (maximum resemblance) between an unknown image and a known reference image. Such a biasing effect permits complex images, such as occur in inverse syntheticaperture- radar imaging, to be well reconstructed. The algorithm permits complex amplitudes to replace the probabilities in the Rényi form. The bias image may be constructed as a smooth version of the linear, Fourier reconstruction of the data. Examples on simulated complex image data with and without noise indicate that the Rényi reconstruction approach permits superresolution in low-noise cases and higher fidelity than ordinary, linear reconstructions in higher-noise cases.     

Suppliers’ green performance evaluation using fuzzy extended ELECTRE approach

In the present context of the globalized market, sustainable manufacturing has become a major concern for all organizations. The sustainable manufacturing system includes economic, environmental, and social sustainabilities. Green manufacturing enhances the environmental sustainability but, it also affects the economic and social sustainabilities. The compulsion to follow the environmental rules and regulation in any business activity has increased the awareness for the use of green products, recyclable materials for packaging, reduction of carbon emission, etc. Due to the involvement of extra costs in green manufacturing, some ignorance in the implementation of green practices may be observed. To ensure sustainable systems, selection of suppliers based on green performance measures is very important. This study evaluates the suppliers’ performances based on Green Practices as follows: environmental management and pollution control, cost, quality, and flexibility using the fuzzy-extended Elimination and Choice Expressing Reality approach. This approach helps the managers to incorporate the linguistic decision of the decision makers and convert it into quantitative scale. This method is used to eliminate and outrank the poor performers. As poor performers are outranked, this approach helps to select the most suitable green suppliers as per organization’s requirement.