3,496 research outputs found
Inherited LU-factorizations of matrices
No full textAbstractVarious types of LU-factorizations for nonsingular matrices, where L is a lower triangular matrix and U is an upper triangular matrix, are defined and characterized. These types of LU-factorizations are extended to the general m×n case. The more general conditions are considered in the light of the structures of [C.R. Johnson, D.D. Olesky, P. Van den Driessche, Inherited matrix entries: LU factorizations, SIAM J. Matrix Anal. Appl. 10 (1989) 99–104]. Applications to graphs and adjacency matrices are investigated. Conditions for the product of a lower and an upper triangular matrix to be the zero matrix are also obtained
Minimum deviation, quasi-LU factorization of nonsingular matrices
No full textAbstractNot all matrices enjoy the existence of an LU factorization. For those that do not, a number of “repairs” are possible. For nonsingular matrices we offer here a permutation-free repair in which the matrix is factored L˜U˜, with L˜ and U˜ collectively as near as possible to lower and upper triangular (in a natural sense defined herein). Such factorization is not generally unique in any sense. In the process, we investigate further the structure of matrices without LU factorization and permutations that produce an LU factorization
La politica della legalità : il ruolo del giurista nell'età contemporanea
No full textAs the author of this book shows as he tests his theses, impartiality and justice require specific and scrupulous forms of civil engagement which render obsolete the traditional call for neutrality. At the same time, citizens must be made to understand how formal features of law that usually evoke their hostility actually guarantee their rights. The legal professional must learn to be a "relativist", obliged - through his choices - to establish priorities among distinct and often irreconcilable value domains
Cercando di dimenticare Savigny
No full textIl presente scritto è un contributo alla discussione del libro di Aurelio Gentili, Il
diritto come discorso del 2013. Del predetto volume si approvano senza riserve
a) la critica alla concezione del vecchio positivismo, secondo il quale il giurista
non farebbe altro che esplorare un misterioso oggetto denominato “realtà
giuridica”, e b) l’interesse per le tecniche argomentative quali strumenti di
controllo interno dei discorsi. Sul piano propositivo, l’autore della recensione
ammette che la conoscenza dei significati normativi letterali, quando la si
ritiene rilevante, comporta a livello collettivo (ma assai meno al livello dei
singoli) un giudizio partecipante. Tali significati, del resto, lungi dall’essere
entità fisse, sono sempre in movimento. Ciò stabilito e con questi limiti,
occorre ammettere che non c’è solo un ordo ordinans imposto dai giuristi sui
confusi materiali estratti dalle fonti, ma si può scorgere, e si deve ritrovare,
anche un ordo ordinatus, frutto tanto dell’attività legislativa quanto delle precedenti interpretazioni, che il singolo interprete non può far a meno di
riconoscere. Insomma: tra i due ordini, fra le attività dei giuristi e i prodotti di
tali attività, si stabilisce un rapporto dialettico.This article is a contribution to the discussion regarding Aurelio Gentili’s 2013
book Il diritto come discorso. From the said volume, the author fully approves:
a) the criticism of the old positivism’s conception that a lawyer does nothing
but explore the misterious object that is “legal reality”, and b) the interest in
argumentative techniques as instruments for internal control of discourses. The
author of this article proposes admitting that the knowledge of literal normative
meanings, when believed to be relevant, requires at the level of the collective
(much less so at the individual level) a judgment, which demonstrates
participation. These meanings are, moreover, far from being fixed entities,
always changing. Within these limits, it should be admitted that there is not
only an ordo ordinans, made by the jurists, using the confused materials
extracted from the sources, but that we may also observe, and must rediscover,
an ordo ordinatus, which results from both legislative activity and previous
interpretations – that an individual interpreter cannot but recognize. In short, a
dialectic relationship between the two orders, between the activity of lawyers
and the products of these activities, is thus established
Exact two-dimensionalization of low-magnetic-Reynolds-number flows subject to a strong magnetic field
No full textWe investigate the behavior of flows, including turbulent flows, driven by a horizontal body-force and subject to a vertical magnetic field, with the following question in mind: for very strong applied magnetic field, is the flow mostly two-dimensional, with remaining weak three-dimensional fluctuations, or does it become exactly 2D, with no dependence along the vertical? We restrict attention to low-magnetic-Reynolds number (Rm) flow. Because liquid metals have low magnetic Prandtl number, such low- flows can have a kinetic Reynolds number as large as one million and therefore be strongly turbulent. We first focus on the quasi-static approximation, i.e. the asymptotic limit of vanishing magnetic Reynolds number Rm << 1: we prove that the flow becomes exactly 2D asymptotically in time, regardless of the initial condition and provided the interaction parameter N is larger than a threshold value. We call this property absolute two-dimensionalization: the attractor of the system is necessarily a (possibly turbulent) 2D flow. We then consider the full-magnetohydrodynamic equations and we prove that, for low enough Rm and large enough N, the flow becomes exactly two-dimensional in the long-time limit provided the initial vertically-dependent perturbations are infinitesimal. We call this phenomenon linear two-dimensionalization: the (possibly turbulent) 2D flow is an attractor of the dynamics, but it is not necessarily the only attractor of the system. Some 3D attractors may also exist and be attained for strong enough initial 3D perturbations. These results shed some light on the existence of a dissipative anomaly for magnetohydrodynamic flows subject to a strong external magnetic field
Letter from Lee C.R. Baker, Reference Assistant to Michi Weglyn, September 25, 1974
No full textThis letter refers to a thesis written by Warren Page Rucker in 1970 entitled, "United States--Peruvian Policy Toward Peruvian-Japanese Persons During World War II." Baker explains that Weglyn can purchase a copy of the thesis if she so desires.Collection of notes, articles, correspondence, photographs, and term papers collected by Yukio Mochizuki, a student at CSU Dominguez Hills, while researching Japanese American incarceration and Japanese Peruvian internment during World War II
Flow instabilities and reversals in non-uniformly thermocapillary driven melt pool
No full textWith transient LES and DNS simulations, we investigate flow in melt pools driven by thermocapillary forces. The developing pool is at first axisymmetric as are the boundary conditions, but flow instabilities arise that lead to 3D oscillatory flow patterns. At higher laser powers a sign-change in the surface tension temperature coefficient occurs, resulting in a flow reversal in the pool and thus two counter-rotating vortices, which exhibit similar though more complex flow instabilities
Wall to wall optimal transport
No full textThe calculus of variations is employed to find steady divergence-free velocity fields that maximize transport of a tracer between two parallel walls held at fixed concentration for one of two constraints on flow strength: a fixed value of the kinetic energy or a fixed value of the enstrophy (the mean square rate of strain in this situation). The optimizing flows realize upper limits on convective transport in this scenario. We interpret the results in the context of buoyancy-driven Rayleigh–Bénard convection problems that satisfy the flow intensity constraints, enabling us to investigate how optimal transport scalings compare with upper bounds on Nu expressed as a function of the Rayleigh number Ra
Holding on to What is Most Precious: Ohio Juvenile Law after In re C.R.
Full text linkThis article will endeavor to show that the Ohio Supreme Court’s ruling in In re C.R. makes it too difficult for parents to retain custody of their own children. By exploring United States Supreme Court precedent, it will be shown that the rule emerging from In re C.R. does not pass procedural due process muster. It will also be shown that the Ohio Supreme Court disregarded its own precedent and in doing so, created a rule that undermines the policies of its own juvenile law system. By providing the rudiments of juvenile jurisprudence, the facts and decision of In re C.R., and an analysis that shows the Ohio Supreme Courts’ oversights and errors in its decision, the author hopes to persuade Ohio lawmakers to reevaluate the way that juvenile court custody cases should be conducted in the future
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