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Rehabilitation and Enhancement of the Urban Heritage of the Nineteenth Century
No full textrehabilitation, urban heritage, Nineteenth Centur
GPU-only unified ConvMM layer for neural classifiers
No full textConvolution is most computationally intensive task of Convolutional Neural Network(CNN). It demands both computational power and memory storage of processing unit. There are different approaches to compute the solution of convolution. In this paper, matrix multiplication based convolution(ConvMM) approach is implemented and accelerated using concurrent resources of Graphics Processing Unit(GPU). CUDA computing language is used to implement this layer. Performance of this GPU-only convolutional layer is compared with its heterogeneous version. Further, flow of this GPU-only convolutional layer is optimized using Unified memory by eliminating overhead caused by extra memory transfers
Quantifying the micro-architectural similarity of bioceramic scaffolds to bone
No full textPorous bioceramics for bone repair should ideally mimic the micro-architectural characteristics of bone and promote the growth of regenerated tissue inside their pores. Assessment of the similarity between scaffold and bone in a quantitative and reliable way still remains an open challenge that we tackled in this work. We produced glass-ceramic scaffolds with two different nominal porosities by polymer sponge replication and characterized their three-dimensional architecture through non-destructive X-ray micro-computed tomography. Six key independent features were measured, namely total porosity, pore interconnectivity, pore size distribution, specific surface area, connectivity density and degree of anisotropy. In order to enable quantitative and objective comparison between bioceramic scaffolds and bone, each of the above-mentioned independent characteristics measured in the scaffold was compared to the corresponding feature in human trabecular bone. A multiparametric score, which comprises all the estimated features, was also developed and used to evaluate the similarity between the produced scaffolds. These quantitative comparisons can allow researchers to identify reliably the scaffold that more closely resembles the bone micro-architecture, suggesting the possible use of this approach to guide the design, manufacturing and selection of biomimetic ceramic scaffolds
Estimation accuracy vs. engineering significance of contact parameters for solid dampers
No full textAll numerical models of friction-damped bladed arrays require knowledge or information of contact-friction parameters. In the literature, these parameters are typically tuned so that the experimental Frequency Response Function (FRF) of a damped blade matches its numerical counterpart. It is well known that there exist multiple combinations of contact parameters capable of satisfying a given experimental-numerical FRF match. A better approach towards a finer tuning could be based on directly measuring contact forces transmitted between blade platforms through the damper: in this case friction coefficients are estimated through tangential over normal force components during those hysteresis segments which are safely identified as being in a slip condition. This has been applied by these authors to rigid bar (solid) dampers. Unfortunately, the four contact stiffness values (left and right damper-platform contact, normal and tangential) are more than the measurements available in the technique presentedby these authors. Therefore, the problem is underdetermined. The purpose of this paper is twofold, i.e., to propose an alternative way to estimate contact stiffness values (i.e. thus solving the under-determinacy mentioned above) and to check the effective significance of such estimates from a practical engineering point of view. The contact parameter estimation technique proposed by these authors produces, for each contact parameter, a best-fit value and an uncertainty band. It will be shown that the uncertainty affecting each contact parameter results in an uncertainty on the equivalent damping and stiffness indicators at blade level which is lower than 5%
Influence of lateral confining pressure on flow number tests
No full textThe study described in this paper aimed to investigate the rutting resistance of bituminous mixtures by means of flow number tests, with a particular emphasis placed on the analysis of the effects produced by var-iations of lateral confinement. Two wearing course mixtures, one standard dense-graded and one rubberized gap-graded, were employed in the experimental investigation in order to highlight the influence of confining pressure on materials with significantly different bulk structure and rheological properties of the binder phase. Flow number tests were carried out at a single test temperature and in three confinement conditions on cylindrical samples compacted at two air void contents. Obtained results suggest that confining pressure can significantly affect flow number values to an extent that depends on mixture type and composition, indi-cating the importance of selecting proper testing conditions in order to achieve a reliable performance-based ranking of materials
TMR technique for mutex kernel data structures
No full textGuaranteeing the correct system behaviour in safety-critical computer-based systems is a challenging issue due to transient faults. This has been demonstrated considering the effects of faults in memory elements containing data structures belonging to a Unix-based Operating System. Elements linked to resource and process synchronization management are particularly critical, thus the need for hardening also the kernel data structures. In order to overcome this vulnerability, a solution is proposed by implementing a triplication technique in the source code of the Linux kernel, aiming at incrementing the robustness of the system. An experimental fault injection analysis has been conducted on the Mutex semaphores to evaluate its effectiveness. The proposed approach successfully detected and corrected the noxious effects generated by single faults in the system with a limited performance overhead
Influence of column shear failure on pushover based assessment of masonry infilled reinforced concrete framed structures: A case study
No full textStructural frames, constructed either of steel or reinforced concrete (RC), are often infilled with masonry panels. However, during the analysis of the structural frames, it has become common practice to disregard the existence of infills because of the complexity in modeling. This omission should not be allowed because the two contributions (of infills and of frames) complement each other in providing a so different structural system. The use of different modeling assumptions significantly affects the capacity as well as the inelastic demand and safety assessment. In specific, the adoption of equivalent diagonal pin-jointed struts leaves open the problem of the evaluation of the additional shear on columns and consequently of the choice of a proper eccentricity for the diagonal struts. In this context, this paper presents the results of a real case study. The seismic performance of the RC structure of a school is evaluated by using concentric equivalent struts for modeling infills and the level of the additional shear on the columns is fixed as a rate of the axial force on them in agreement to a strong correlation obtained after a numerical experimentation. Hence, the applicability of the correlation mentioned before is shown and the form in which the results can be provided is presented. The characteristics of the new approach, first time applied to a real case, are highlighted by a comparison between the performance obtainable with different modeling detail levels of the infills. Through the paper, it is proved that the simplified evaluation of the additional shear demand produced by infills just for the base columns is sufficient to warn that a simplified model disregarding infills or based on the use of concentric struts for the infills may considerably overestimate the structural capacity. Further, by the study of a real case, the paper provides an overview of the models developed by the authors to obtain the capacity of reinforced concrete framed structure for the practical applications
Stakeholders' roles for Business Modelling in a City Logistics ecosystem: towards a conceptual model
No full textA major challenge associated with the implementation of CL initiatives lies with their economic and financial long-term success. In this context, the business model concept can support assessing the business side of stakeholders' decision-making processes as major determinants for such success. The purpose of this work is to overcome the shortcomings of the business model approach applied to CL systems. To this end, a conceptual model is built from a role-based business ecosystem modelling approach to provide a business model representation of the CL business ecosystem, able to identify and explore the components of the system and their dynamics
Strong dopant dependence of electric transport in ion-gated MoS2
No full textWe report modifications of the temperature-dependent transport properties of MoS2 thin flakes via field-driven ion intercalation in an electric double layer transistor. We find that intercalation with Li+ ions induces the onset of an inhomogeneous superconducting state. Intercalation with K+ leads instead to a disorder-induced incipient metal-to-insulator transition. These findings suggest that similar ionic species can provide access to different electronic phases in the same material