Papers by Monica Ciminello
Purpose: To design a computer-aided detection (CADe) system for clustered microcalcifications in ... more Purpose: To design a computer-aided detection (CADe) system for clustered microcalcifications in reconstructed digital breast tomosynthesis (DBT) volumes and to perform a preliminary evaluation of the CADe system. Methods: IRB approval and informed consent were obtained in this study. A data set of two-view DBT of 72 breasts containing microcalcification clusters was collected from 72 subjects who were scheduled to undergo breast biopsy. Based on tissue sampling results, 17 cases had breast cancer and 55 were benign. A separate data set of two-view DBT of 38 breasts free of clustered microcalcifications from 38 subjects was collected to independently estimate the number of false-positives (FPs) generated by the CADe system. A radiologist experienced in breast imaging marked the biopsied cluster of microcalcifications with a 3D bounding box using all available clinical and imaging information. A CADe system was designed to detect microcalcification clusters in the reconstructed volume. The system consisted of prescreening, clustering, and false-positive reduction stages. In the prescreening stage, the conspicuity of microcalcification-like objects was increased by an enhancement-modulated 3D calcification response function. An iterative thresholding and 3D object growing method was used to detect cluster seed objects, which were used as potential centers of microcalcification clusters. In the cluster detection stage, microcalcification candidates were identified using a second iterative thresholding procedure, which was applied to the signal-to-noise ratio (SNR) enhanced image voxels with a positive calcification response. Starting with each cluster seed object as the initial cluster center, a dynamic clustering algorithm formed a cluster candidate by including microcalcification candidates within a 3D neighborhood of the cluster seed object that satisfied the clustering criteria. The number, size, and SNR of the microcalcifications in a cluster candidate and the cluster shape were used to reduce the number of FPs. Results: The prescreening stage detected a cluster seed object in 94% of the biopsied microcalcification clusters at a threshold of 100 cluster seed objects per DBT volume. After clustering, the detection sensitivity was 90% at 15 marks per DBT volume. After FP reduction, at 85% sensitivity, the average number of FPs estimated using the data set containing microcalcification clusters was 3.8 per DBT volume, and that estimated using the data set free of microcalcification clusters was 3.4. The detection performance for malignant microcalcification clusters was superior to that for benign clusters. Conclusions: Our study indicates the feasibility of the 3D approach to the detection of clustered microcalcifications in DBT and that the newly designed enhancement-modulated 3D calcification response function is promising for prescreening. Further work is needed to assess the generalizability of our approach and to improve its performance. V C 2012 American Association of Physicists in Medicine.
Synchronized Switched Shunt Control Technique Applied on a Cantilevered Beam: Numerical and Experimental Investigations
Journal of Intelligent Material Systems and Structures, 2008
... Journal of Intelligent Material Systems and Structures Monica Ciminello, Antonio Calabrò, Sal... more ... Journal of Intelligent Material Systems and Structures Monica Ciminello, Antonio Calabrò, Salvatore Ameduri and Antonio Concilio Experimental Investigations Synchronized Switched Shunt Control Technique Applied on a Cantilevered Beam: Numerical and Published by: ...
Multitone Switching Shunt Control by a PZT Network Embedded into a Fiberglass Panel: Design, Manufacture, and Test
Journal of Intelligent Material Systems and Structures, 2010
ABSTRACT Research in noise and vibration control has partially focused on semi-active attenuation... more ABSTRACT Research in noise and vibration control has partially focused on semi-active attenuation techniques such as switching shunt control (SSC) systems. Among the various methods, SSC architectures exhibit several interesting advantages such as low power absorption and intrinsic adaptive capabilities. This approach may represent an acceptable compromise between passive and active solutions. In previous work the authors implemented and validated 1D and 2D numerical models, addressed to describe continuous simple isotropic structures under tonal excitations controlled by single-element SSC system. Further efforts were then directed to extend the applicability of those models to non-isotropic structures and to multi-tone control devices. In this article, a 6-PZT network multi-tone SSC system is presented, and embedded into a balanced fiberglass laminate. The network geometry is defined according to an optimization process following modal information. The former 1-channel control circuit was extended to drive up to four independent channels. The complete system dynamics was simulated by assembling the structural matrices into a Matlab code, where both the electromechanical coupling and the control circuit behavior were taken into account. The structure was excited by broadband sweep signals in a selected range. Numerical and experimental results were compared and discussed.
FE Modeling of an Innovative Vibration Control Shunt Technique
Journal of Intelligent Material Systems and Structures, 2008
The possibility of simulating and predicting the dynamic behavior of controlled structural system... more The possibility of simulating and predicting the dynamic behavior of controlled structural systems is a challenging goal because of the complexity of the related architectures. As a matter of fact, obtaining accurate information on system response in pre-design and design phases may reduce both computational and experimental efforts. In this study, the numerical simulation of a specific family of semi-active vibration control devices is taken into account: piezoelectric acting in the synchronized switched shunt architecture (SSSA). Different from the classic shunt inductive architecture, the SSSA is characterized by a switch component adaptively synchronized with the structural response to be controlled, whatever it is. The ability of controlling low range frequencies without large limitations in terms of inductive components represents, together with the adaptive skill, the main advantage of this technique. The reference structure is represented by an isotropic plate, clamped on the edges; the active system is made of an isolated PZT patch, located at the center. A dedicated simulation tool has been realized and implemented to predict piezo effectiveness for the considered configuration. Related matrices have been suitably integrated within the complete model. The switching state of the electrical circuit causes the matrices elements to be time-variant; the related problems have been dealt with in a Newmark-Beta-based integration solver. The integrated structural system has been fully and simultaneously simulated, considering at the same time the structural dynamics, the nonlinear behavior of the electrical device, and the piezoelectric electromechanical response. Results have been presented in terms of time response. The innovative contribution reported in this study concerns the application of the FE approach to the design of a SSSA integrated within MDOF structural systems. A characteristic of the approach is the ability of interacting with commercial FE codes, like MSC-Nastran, in designing and simulating the SSSA control action. References reported in this study face the SSSA control problem applied to single DOF systems (not directly applicable to complex systems, but through modal analysis reduction operations) or deal with FE simulation of classical inductive shunt (not switched). The details of this statement are fully reported in the Introduction.
Journal Articles by Monica Ciminello
Smart Structures and Systems, 2015
Today, as railways increase their capacity and speeds, it is more important than ever to be compl... more Today, as railways increase their capacity and speeds, it is more important than ever to be completely aware of the state of vehicles fleet's condition to ensure the highest quality and safety standards, as well as being able to maintain the costs as low as possible. Operation of a modern, dynamic and efficient railway demands a real time, accurate and reliable evaluation of the infrastructure assets, including signal networks and diagnostic systems able to acquire functional parameters. In the conventional system, measurement data are reliably collected using coaxial wires for communication between sensors and the repository. As sensors grow in size, the cost of the monitoring system can grow. Recently, auto-powered wireless sensor has been considered as an alternative tool for economical and accurate realization of structural health monitoring system, being provided by the following essential features: On-board micro-processor, sensing capability, wireless communication, auto-powered battery, and low cost. In this work, an original harvester device is designed to supply wireless sensor system battery using train bogie energy. Piezoelectric materials have in here considered due to their established ability to directly convert applied strain energy into usable electric energy and their relatively simple modelling into an integrated system. The mechanical and electrical properties of the system are studied according to the project specifications. The numerical formulation is implemented with in-house code using commercial software tool and then experimentally validated through a proof of concept setup using an excitation signal by a real application scenario. Copyright © 2015 Techno-Press, Ltd.
Archive of Mechanical Engineering, 2017
Winglets are introduced into modern aircraft to reduce wing aerodynamic drag and to consequently ... more Winglets are introduced into modern aircraft to reduce wing aerodynamic drag and to consequently optimize the fuel burn per mission. In order to be aerodynamically effective, these devices are installed at the wing tip section; this wing region is generally characterized by relevant oscillations induced by flights maneuvers and gust. The present work is focused on the validation of a continuous monitoring system based on fiber Bragg grating sensors and frequency domain analysis to detect physical condition of a skin-spar bonding failure in a composite winglet for in-service purposes. Optical fibers are used as deformation sensors. Short Time Fast Fourier Transform (STFT) analysis is applied to analyze the occurrence of structural response deviations on the base of strain data. Obtained results showed high accuracy in estimating static and dynamic deformations and great potentials in detecting structural failure occurrences.
Book chapters by Monica Ciminello
Computational Methods in Applied Sciences (Springer), 2017
Shape control of adaptive wings has the potential to improve wing aerodynamic performance in off-... more Shape control of adaptive wings has the potential to improve wing aerodynamic performance in off-design conditions. A possible way to attain this objective is to implement specific technologies for trailing edge morphing, aimed at changing the airfoil camber. In the framework of SARISTU project (EU-FP7), an innovative structural system incorporating a gapless deformable trailing edge was developed. A related key technology is the capability to emulate and maintain pre-selected target wing shapes within an established margin, enabling optimal aerodynamic performance under current operational pressure loads. In this paper, the actuation and control logics aimed at preserving prescribed geometries of an adaptive trailing edge under variable conditions are numerically and experimentally detailed. The actuation concept relies on a quick-return mechanism, driven by load-bearing actuators acting on morphing ribs, directly and individually. The adopted unshafted distributed electromechanical system arrangement uses servo-rotary actuators, each rated for the torque of a single adaptive rib of the morphing structure. The adopted layout ensures compactness and weight limitations , essential to produce a clean aerodynamic system. A Fiber Bragg Grating (FBG)-based distributed sensor system generates the information for appropriate open-and closed-loop control actions and, at the same time, monitors possible failures in the actuation mechanism.
Conferences Papers by Monica Ciminello
Proceedings of the 24th AIAA/AHS Adaptive Structures Conference (San Diego - CA, USA), 2016
Aircraft wings are usually optimized for a specific design point. However, since they operate in ... more Aircraft wings are usually optimized for a specific design point. However, since they operate in a wide variety of flight regimes, some of these have conflicting impacts on aircraft design process, as a single configuration may be efficient in one instance but perform poorly in others. In principle, stiff, hardly deformable aircraft structures preclude any adaptation to changing conditions. Alternatively, morphing wings could provide adaptive capabilities to maximize aircraft performance in any flight operation. Inside SARISTU, specific research activities were carried out on the technological development of an Adaptive Trailing Edge Device (ATED) implementing airfoil camber morphing for the maximization of the wing aerodynamic performance during cruise, with the ultimate goal to reduce fuel consumption. Wing shape is changed to compensate weight losses following fuel burning, to keep L/D ratio (or simply drag, D) to its optimal value. ATED camber adaptations are predicted to lead to significant benefits in fuel consumption, estimated from 3 to 5%, depending on a number of initial and boundary conditions. This paper is focused on the design process adopted for the definition and verification of ATED primary structure; fast and reliable elementary methods combined with rational design criteria and advanced FE analyses were adopted to assess the architectural concept and the embedded actuation mechanisms. Structural design was carried out in compliance with the very demanding requirements posed by the implementation of the device on large Aeroplanes (EASA CS25 category). © 2016, American Institute of Aeronautics and Astronautics Inc, AIAA, All rights reserved.
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Papers by Monica Ciminello
Journal Articles by Monica Ciminello
Book chapters by Monica Ciminello
Conferences Papers by Monica Ciminello