Improving an interior-point approach for large block-angular problems by hybrid preconditioners

The computational time required by interior-point methods is often domi- nated by the solution of linear systems of equations. An efficient spec ialized interior-point algorithm for primal block-angular proble ms has been used to solve these systems by combining Cholesky factorizations for the block con- straints and a conjugate gradient based on a power series precon ditioner for the linking constraints. In some problems this power series prec onditioner re- sulted to be inefficient on the last interior-point iterations, wh en the systems became ill-conditioned. In this work this approach is combi ned with a split- ting preconditioner based on LU factorization, which is main ly appropriate for the last interior-point iterations. Computational result s are provided for three classes of problems: multicommodity flows (oriented and no noriented), minimum-distance controlled tabular adjustment for statistic al data protec- tion, and the minimum congestion problem. The results show that , in most cases, the hybrid preconditioner improves the performance an d robustness of the interior-point solver. In particular, for some block-ang ular problems the solution time is reduced by a factor of 10.Peer ReviewedPreprin

A two years simulation using a real data cellular automaton: A predictive case study with the schistosomiasis expansion process along the coastline of Brazil

This work presents a Cellular Automata model to characterize the social and environmental factors which contribute for the analysis of the expansion process of Schistosoma mansoni infection in Pernambuco - Brazil. The model has been experimented with a set of two years real data from a study area at North Coast of Pernambuco – Brazil. The main constraint equations, the modelling process and the results obtained until now with the simulating scenarios generated are presented here. The results identify, as in field works, endemic areas and human risk infection areas. Furthermore, predictive scenarios for a look ahead with a perspective into fifteen years are also presented.Peer ReviewedPostprint (published version

Afetação dos direitos coletivos e da segurança alimentar na sentença da Corte Internacional de Justiça caso Nicarágua vs. Colômbia

This article addresses the state of collective rights and the Food Security of the Raizales community, who were affected by the decision of the International Court of Justice, case Nicaragua vs. Colombia. Their ancestral fishing rights are directly restricted, which puts them at risk for access, availability, and permanence of the fishing resource. For this purpose, first the exposition of Nicaragua vs. Case Colombia. Second. Food Security as a right and obligation in international law. Third, the affectation of the collective rights and the food security of the Raizales in San Andrés. Fourth, what does the near future hold out from the international scenario and finally the conclusion on whether the International Court of Justice in its decisions should take into account social, economic and cultural rights as well as collective rights to take substantive decisions in territorial disputes where the rights of customary groups of special protection groups are violated.El presente artículo aborda el estado de los derechos colectivos y de la Seguridad Alimentaria del Pueblo raizal miskitos, afectados por el fallo de la Corte Internacional de Justicia caso Nicaragua vs. Colombia, que de manera directa restringe sus derechos ancestrales de pesca lo que pone en riesgo para ellos el acceso, la disponibilidad y permanencia del recurso pesquero.  Para ello se desarrollará i. la Seguridad Alimentaria como derecho y obligación en el derecho internacional. ii. el Caso Nicaragua vs. Colombia iii. la afectación de los derechos colectivos y la seguridad alimentaria de los Raizales en San Andrés. iv. consecuencias desde el escenario internacional y v. conclusión sobre si la Corte Internacional de Justicia debe tener en cuenta los derechos sociales, económicos y culturales, así como los derechos colectivos para tomar decisiones de fondo en disputas territoriales donde resulten vulnerados derechos consuetudinarios de grupos poblacionales de especial proteccióno presente artigo aborda o estado dos direitos coletivos e dasegurança alimentar do povo raizal, afetados pela sentença da CorteInternacional de Justiça caso Nicarágua vs. Colômbia, que de maneira direta restringe seus direitos ancestrais de pesca o que põe em risco para eles o acesso, a disponibilidade e permanência do recurso pesqueiro. Para isso se desenvolverá i) o Caso Nicarágua vs. Colômbia, ii) a Segurança Alimentar como direito e obrigação no direito internacional, iii) a afetação dos direitos coletivos e a segurança alimentar dos Raizais em San Andrés, Providencia e Santa Catalina, iv) Consequencias desde o cenário internacional. Se apresentará uma conclusão sobre se a Corte Internacional de Justiça deve ter em consideração os direitos sociais, econômicos e culturais, assim como os direitos coletivos para tomar decisões de fundo em disputas territoriais onde resultem vulnerados direitos consuetudinários de grupos populacionais de especial proteção

Caracterización fisicoquímica y determinación de parámetros óptimos (temperatura y acondicionamiento de materia prima) en el proceso de secado por aire caliente del Loche (Cucurbita moschata Duchesne), para la obtención de harina de Loche

El objetivo de esta investigación es obtener harina de loche determinando los parámetros óptimos de secado y su acondicionamiento, además de las características fisicoquímicas. Para el estudio se empleó loche fresco en su madurez fisiológica y con buen estado sanitario caracterizándolo fisicoquímicamente según métodos establecidos en la AOAC (1997). El fruto se acondiciono de tres formas: rallado (8 cm dé largo, 0,40cm de ancho y 0.07cm de espesor), rodajas {0.15 cm de espesor y 8 cm de diámetro) y triturado (bandejas con dimensiones de 20 cm de largo, 12 cm de ancho y 2 cm de altura), después colocadas en un secador de bandejas con aire caliente hasta llegar a una humedad constante. Se ensayaron tres temperaturas de secado de 60, 70 y 80°C, a una velocidad de aire de 2.0 m/s, y a través de curvas de secado se determinó la humedad, tiempo crítico, velocidad de secado y tiempo total de secado, en la etapa de molienda se determinó su granulometría, para luego caracterizar fisicoquímicamente según Norma técnica peruana para harinas sucedáneas de la harina de trigo (NTP 205.040), y finalmente determinar la isoterma. Dé los resultados experimentales se indicó que el toche triturado y secado a 70°C obtuvo un tiempo de secado de 121.7 minutos y una coloración amarillo intermedio parámetros que fueron los más aceptables en la obtención de la harina de loche comparados a los otros en estudio, una humedad final de 4.63% y obteniendo una granulometría del 35.13% para el tamiz N° 100 (150 um) aceptable para la harina

AMeTHYST (AMbulatory HYstérectomy surgery) : faisabilité de l'hystérectomie en ambulatoire, étude préliminaire

Introduction: hysterectomy is one of the most performed surgery in women. CNGOF recommends the use of laparoscopic or vaginal routes. One-day surgery is a goal for public authorities who have set a target of 66% in 2020 in France. The aim of the study was to evaluate the feasibility of one-day surgery for mini-invasive hysterectomy and identify the predictive factors of succeed and failing. Materials and Methods: we conducted a prospective bicentric observational study at Caen University Hospital and Amiens University Hospital between 09/29/17 and 06/15/18. We included hospitalized patients managed for a laparoscopic or vaginal hysterectomy. Two groups “able” and “unable” have been designed according to the 6 hours past surgery’s PADSS score. A questionnaire was also given to patients during the hospitalization. Results: 50 patients were included during the study period. Half was in the "able" group. Laparotomy history was significantly predictive to discharge inability. Uterine size and BMI were not predictive criteria. The main limits to the discharge were pain and postoperative nausea / vomiting. 4 patients had grade 1 postoperative complications (acute urine retention), they were all in the "unable" group. Conclusion: one-day minimally invasive hysterectomy is possible and safe. Patient’s complete engagement is key for success.Introduction : l'hystérectomie est une des interventions les plus pratiquées chez la femme en France aujourd’hui. Les voies coelioscopiques et vaginales sont les techniques recommandées par le CNGOF. La chirurgie ambulatoire est devenue une priorité pour les pouvoirs publics qui ont fixé un objectif de 66% de chirurgie ambulatoire en 2020 en France. Notre objectif était d’évaluer la faisabilité de l’hystérectomie mini-invasive en ambulatoire et d’identifier les facteurs prédictifs de réussite et d’échec. Patientes et méthodes : nous avons réalisé une étude prospective observationnelle bicentrique sur le CHU de Caen et d’Amiens entre le 29/09/2017 et le 15/06/2018. Nous avons inclus les patientes prise en charge pour une hystérectomie par voie coelioscopique ou vaginale et hospitalisée en service conventionnel. Nous avons évalué le score de PADSS à 6 heures de la fin de l’intervention afin de classer nos patientes en 2 groupes « apte » (score de PADSS ≥ 9) et « inapte ». Un questionnaire était également remis aux patientes pendant l’hospitalisation. Résultats : 50 patientes ont été inclus sur la période. 50% des patientes étaient dans le groupe « apte ». Un antécédent de laparotomie était un critère significativement prédictif d’une inaptitude à la sortie. La taille de l’utérus et l’IMC n’étaient pas des critères prédictifs. Les principaux freins à une sortie étaient la douleur et les nausées/vomissements post-opératoires. 4 patientes ont présenté des complications de grade 1 en post-opératoire (rétention aigue d’urine), elles étaient toutes dans le groupe « inapte ». Conclusion : l'hystérectomie mini-invasive est licite et sûre en ambulatoire. L’adhésion de la patiente est un critère essentiel pour cette prise en charge

Improving an interior-point approach for large block-angular problems by hybrid preconditioners

The computational time required by interior-point methods is often domi- nated by the solution of linear systems of equations. An efficient spec ialized interior-point algorithm for primal block-angular proble ms has been used to solve these systems by combining Cholesky factorizations for the block con- straints and a conjugate gradient based on a power series precon ditioner for the linking constraints. In some problems this power series prec onditioner re- sulted to be inefficient on the last interior-point iterations, wh en the systems became ill-conditioned. In this work this approach is combi ned with a split- ting preconditioner based on LU factorization, which is main ly appropriate for the last interior-point iterations. Computational result s are provided for three classes of problems: multicommodity flows (oriented and no noriented), minimum-distance controlled tabular adjustment for statistic al data protec- tion, and the minimum congestion problem. The results show that , in most cases, the hybrid preconditioner improves the performance an d robustness of the interior-point solver. In particular, for some block-ang ular problems the solution time is reduced by a factor of 10.Peer Reviewe