1,721,646 research outputs found
Efficient non-linear 3D electrical tomography reconstruction
No full textNon-linear electrical tomography imaging can be performed efficiently if certain optimisations are applied to the computational reconstruction process. We present a 3D non-linear reconstruction algorithm based on a regularized conjugate gradient solver and discuss the optimisations which we incorporated to allow for an efficient and accurate reconstruction. In particular, the application of image smoothness constraints or other regularization techniques and auto-adaptive mesh refinement are highly relevant. We demonstrate the results of applying this algorithm to the reconstruction of a simulated material distribution in a cubic volume
Optimal finite element modelling and efficient reconstruction in non-linear 3D electrical resistance tomography
No full textElectrical Impedance Tomography can provide images with well-defined characteristics using a fully non-linear reconstruction process when appropriate constraints are imposed on the solution to allow the ill-posed inverse problem to be solved. Using appropriate finite element discretizations for forward solution and inverse problem offers additional advantages in the image reconstruction process, such as (a) inclusion of prior knowledge, (b) generic model templating to adapt to, for example, individual head shapes, and (c) obtaining accurate results without unnecessary computational overhead. We have developed an efficient 3D non-linear reconstruction algorithm based on a regularized inverse conjugate gradient solver which incorporates (a) local image smoothness constraints, and (b) a number of optimisations which reduce the computing power required to obtain an accurate solution. We show results from applying this to various problems which arise in medical resistivity reconstruction given only surface potential measurements and demonstrate the importance of the FE discretization. Keywords: 3D non-linear electrical impedance tomography, FE template modelling, optimal finite element meshes, 3D visualization, FE discretization
Poster: Efficient Electrical Impedance Tomography for Non-Invasive Medical Imaging
No full textNon-linear Electrical Impedance Tomography (EIT) is a novel technique for non-invasive and cost-effective imaging, which makes it an optimal candidate for medical applications. The basic principles of EIT can be derived from Maxwell's Equations. These need to be solved numerically within the object under investigation using, for example, a finite element mesh. To solve the ill-conditioned inverse problem on this finite discretization, additional constraints have to be applied. In addition, the speed of reconstruction plays an important role and limits number and size of the used elements. The developed self-adaptive mesh refinement algorithm reduces - based on an a posteriori energy error estimate - the number of elements required for an accurate solution compared to conventional uniform meshing techniques. The gained speed-up in the image formation process enhances the potential use of EIT in medical real-time imaging
The “Accountant” stereotype in the Florentine Medieval popular culture: “galantuomini” or usurers?
Full text linkPurpose: This paper explores the stereotype of the accountant in Florentine medieval popular culture based on literary works and from a historical perspective. It aims to highlight how stereotypes change with time and represent the cultural and historical evolution of a society. This research challenges Miley and Read (2012), who stated that the foundation of the stereotype was in Commedia dell'arte, an Italian form of improvisational theatre commenced in the 15th century.
Design/methodology/approach: The authors applied a qualitative research method to examine the accountant from a medieval popular culture perspective. The analysis consists of two phases: (1) categorisation of the accountant stereotype based on accounting history literature and (2) thematic analysis of The Divine Comedy (1307–1313) and The Decameron (1348–1351). The authors explored a synchronic perspective of historical investigation through a “cross-author” comparison, identifying Dante Alighieri as the first key author of medieval popular culture. During his imaginary journey through The Divine Comedy, Dante describes the social, political and economic context of the Florentine people of the 14th century. Then, with its various folkloristic elements, The Decameron of Giovanni Boccaccio becomes the “manifesto” of the popular culture in the Florentine medieval times.
Findings: This study shows the change of the accountant stereotype from the medieval age to the Renaissance. The Divine Comedy mainly connotes a negative accountant stereotype. The 14th century's Florentine gentlemen (“i galantuomini”) are apparently positive characters, with an ordered and clean aspect, but they are accused of being usurers. Dante Alighieri pictures the accountant as a “servant of capitalism”, “dishonest person, excessively fixated with money”, “villain and evil” and “excessively rational”. Giovanni Boccaccio mainly portrays a positive accountant stereotype. The accountant is increasingly more reliable, and this “commercial man” takes a more prestigious role in the society. In The Decameron, the accountant is depicted as a “hero”, “gentleman”, “family-oriented person with a high level of work commitment” and “colourful persona, warm, and emotional”. Overall, the authors provided new evidence on the existence of the accountant stereotype in the Florentine medieval popular.
Originality/value: This study engages with accounting history literature accountants' stereotypes in an unexplored context and time period, providing a base for comparative international research on accounting stereotypes and popular culture. Additionally, it addresses the need for further research on the accountant stereotype based on literary works and from a historical perspective. Therefore, this research also expands the New Accounting History (NAH) literature, focussing on the investigation of the accountant stereotype connotations in the 14th century
La ceramica di Cencelle come strumento di indagine per la ricostruzione funzionale e sociale del contesto quotidiano di una città medievale
Full text linkIl seguente progetto di ricerca ha come scopo quello di ricostruire il contesto funzionale e sociale del quotidiano di una città medievale a partire dall’analisi dei reperti ceramici. Nel venticinquennio di scavi che ha interessato la città di Leopoli-Cencelle, è stato possibile quantificare una mole di materiale che consiste in circa 100.000 frammenti, per un periodo che va dal X al XVI secolo. Mettendo in atto una raccolta dei dati completa, basata sulle metodologie proprie dello studio dei materiali, quali inventariazione, elaborazione di un database, restituzione grafica, studio degli impasti ceramici attraverso analisi archeometriche, si è giunti ad avere un’idea più completa delle morfologie e delle funzioni dei recipienti in questione. In particolare, i manufatti analizzati afferiscono all’area sacra della città (cattedrale romanica e cripta) e ad alcune zone facenti parte della più ampia area dei quartieri residenziali e artigianali, che si presta particolarmente ad uno studio rivolto alla ricomposizione della sfera sociale della popolazione. I frammenti ceramici analizzati, soprattutto appartenenti alle classi ceramiche non rivestite, ci consegnano dei dati legati alle percentuali di presenza/assenza e distribuzione/concentrazione, in riferimento alla realtà sociale della città, all’articolazione degli spazi, alla composizione della popolazione e soprattutto alla sfera dell’alimentazione a cui è stata riservata una particolare attenzione
The secretory capacity of a cell depends on the efficiency of endoplasmic reticulum-associated degradation
No full textPlasma cells, like other "professional" secretory cells, are capable of secreting thousands of proteins per second. To accomplish this impressive task, they contain a highly developed endoplasmic reticulum (ER), where newly synthesized proteins must fold and assemble to native structures before secretion. Protein biogenesis in the ER is coupled to a tight quality control schedule: aberrant molecules produced upon failure of the folding/oligomerization processes are retained in the ER, and eventually degraded by ER-associated degradation (ERAD) pathways. The activity of the ERAD machinery therefore needs to be adapted to variations in the load of the ER with cargo proteins. If ERAD is insufficient, misfolded proteins accumulate causing ER stress, apoptosis, and ER storage diseases. The capacity of ERAD also critically determines the efficiency of protein secretion. Here we summarize recent findings highlighting the role of ERAD in disease and development, particularly in professional secretory cells
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