Certifying isolated singular points and their multiplicity structure

This paper presents two new constructions related to singular solutions of polynomial systems. The first is a new deflation method for an isolated singular root. This construc-tion uses a single linear differential form defined from the Jacobian matrix of the input, and defines the deflated system by applying this differential form to the original system. The advantages of this new deflation is that it does not introduce new variables and the increase in the number of equations is linear instead of the quadratic increase of previous methods. The second construction gives the coefficients of the so-called inverse system or dual basis, which defines the multiplicity structure at the singular root. We present a system of equations in the original variables plus a relatively small number of new vari-ables. We show that the roots of this new system include the original singular root but now with multiplicity one, and the new variables uniquely determine the multiplicity structure. Both constructions are "exact", meaning that they permit one to treat all conjugate roots simultaneously and can be used in certification procedures for singular roots and their multiplicity structure with respect to an exact rational polynomial system

Brown & Campione

http://lascuola.it/nuovadidattica/it/home/contenuti/1382696226582/brown-campion

Bloom

http://lascuola.it/nuovadidattica/it/home/contenuti/1382696226582/bloo

Stenhouse

http://lascuola.it/nuovadidattica/it/home/contenuti/1382696226582/stenhous

Contemporary Chilean cinema and traumatic memory: Andrés Wood’s Machuca and Raúl Ruiz’s Le domaine Perdu

This essay contributes to the scholarship on Chilean cinema’s consistent engagement with the traumatic memory of the dictatorship.i It discusses two recent narrative films, both directed by Chilean auteurs, which depict the experience of the military coup that overthrew the government of Salvador Allende in 1973. The films are: Andrés Wood’s Machuca (2004) and Raúl Ruiz’s Le domaine perdu (2004). Where Machuca largely follows the conventions of mainstream narrative cinema, representing the historical past through a coherent, linear chronology, Le domaine perdu is full of the laberynthine and baroque temporal and narrative juxtapositions that have become Ruiz’s trademark. This essay’s discussion is situated within ongoing debates in memory and trauma studies regarding the question of visual culture’s capacity, or lack of it, to represent trauma. In this respect I will discuss in relation to my analysis ideas by Dominick LaCapra, Joshua Hirsch, Miriam Hansen, and Susannah Radstone. One of the essay’s central concerns is the limits of the trauma framework in facilitating diverse understandings of cultures of political memory. Chile’s contemporary culture of political memory is far from homogenous and this diversity, as I argue here, is expressed in these two films: where Machuca seems driven by a desire to “remember” fixed memories that “act out” the traumas of the military coup, Le domaine perdu encourages responses that “work through” trauma by ellaborating a plural, heterogenous and unfixed sense of historical truth and cultural memory

Dynamic modeling and simulation of a heat pump system for enhancing cycle flexibility

This paper presents a dynamic simulation of a heat pump using butane refrigerant for the purpose of integration with a combined cycle power system and thermal energy storage to enhance flexibility. A dynamic model of a heat pump system is developed using the Amesim software and the simulation result in the case of changing the heat source and heat sink conditions is shown to validate the simulation performance

Performance Assessment of Bladeless Micro-Expanders Using 3D Numerical Simulation

This paper summarizes the development of fully 3D Computational Fluid Dynamics (CFD) analysis for bladeless air micro expander for 200 W and 3 kW rated power. Modelling of nozzle along with rotor is done using structured mesh. This analysis, for the first time, demonstrates the interaction between nozzle and rotor using compressible flow density-based solver. The Shear Stress Transport (SST) turbulence model is employed to resolve wall effects on the rotor and to determine the shear stress accurately. The results illustrate the flow field inside stator and rotor along with complicated mixing zone between stator and rotor. The comparison of rotor-stator CFD simulation results is done with experiments to preliminary validate the model. The losses in the turbine are discussed with the help of experimental and numerical data

Experimental and numerical study of error fields in the CNT stellarator

Sources of error fields were indirectly inferred in a stellarator by reconciling computed and numerical flux surfaces. Sources considered so far include the displacements and tilts (but not the deformations, yet) of the four circular coils featured in the simple CNT stellarator. The flux surfaces were measured by means of an electron beam and phosphor rod, and were computed by means of a Biot-Savart field-line tracing code. If the ideal coil locations and orientations are used in the computation, agreement with measurements is poor. Discrepancies are ascribed to errors in the positioning and orientation of the in-vessel interlocked coils. To that end, an iterative numerical method was developed. A Newton-Raphson algorithm searches for the coils' displacements and tilts that minimize the discrepancy between the measured and computed flux surfaces. This method was verified by misplacing and tilting the coils in a numerical model of CNT, calculating the flux surfaces that they generated, and testing the algorithm's ability to deduce the coils' displacements and tilts. Subsequently, the numerical method was applied to the experimental data, arriving at a set of coil displacements whose resulting field errors exhibited significantly improved quantitative and qualitative agreement with experimental results.Comment: Special Issue on the 20th International Stellarator-Heliotron Worksho

Agenesis of the long head of the biceps brachii tendon: ignored variations of the anatomy and the next tendon to disappear?

Bilateral agenesis of the long head of the biceps brachial tendon (LHB) is a very rare variation of the anatomy. We report a case of an 18-year-old man with bilateral agenesis of the long head of the biceps brachii tendon. We present initial findings, radiographical examinations and the follow-up of an unusual entity. Diagnosis of agenesis of the LHB can be challenging especially in cases of traumatic shoulder pain. It is not a very known entity because of its rareness. However, it could be associated with other congenital anomalies. The absence of the LHB is easily ignored in the diagnostic process. Clinical examination should be a pitfall, radiological examination is helpful to confirm the suspicion of LHB absence. MRI is often the first choice, although ultrasonography is cheaper and much easier to access and it is an excellent tool to visualise this anatomic variation with empty or shallow intertubercular groove