Good practice of receipt of suppliers in a cross docking platform for mass products

En este trabajo se identificara la metodología de programación de citas para los proveedores y los lineamientos que se realiza a los mismos cuando hagan entregas de productos en una plataforma de Cross Docking. Este articulo muestra la problemática que ha tenido la cadena de abastecimiento buscando cumplir tanto en tiempo como en cantidad logrando suplir las necesidades de una tienda, bajo este esquema uno de los caminos que ayudara al cumplimiento es el proceso de Cross Docking el cual busca reducir la manipulación del producto, se puede consolidar y desconsolidar múltiples productos, el costo es mucho menor para un proveedor que entregue en múltiples sitio que ahora lo realice en un solo punto y los más importante el control y trazabilidad del procesamiento de los mismos. Por otra parte, se identifican las metodologías que ayudaran al Cross Docking ser mucho más efectivo en su flujo operativo, mediante una identificación de una administración de malla objetiva tanto para el proveedor como para la operación y la certificación de proveedores que busca reducir el proceso de auditorías y revisión de la mercancía durante el proceso de la misma logrando transformar un proveedor normal a uno estratégico en la compañía.In this paper the methodology of scheduling for providers and guidelines to be undertaken to identify themselves when making deliveries of products in a cross docking platform. This article shows that the problem has been looking for a supply chain meet both time and quantity to meet the needs of managing a store under this scheme one of the ways to help the compliance is Cross Docking process which seeks to reduce product handling, consolidation and deconsolidation can multiple products, the cost is much lower for a supplier to deliver in multiple site now done in a single point and the most important control and traceability of the processing thereof. Likewise methodologies that help the Cross Docking be much more effective in its Effective flow by an identification of a management objective mesh for both the supplier and the operation and certification of providers seeking to reduce the audit process are identified and review of the goods during the same managing to transform a normal supplier to a strategic supplier to the company

Riemannian trust-region methods for strict saddle functions with complexity guarantees

The difficulty of minimizing a nonconvex function is in part explained by the presence of saddle points. This slows down optimization algorithms and impacts worst-case complexity guarantees. However, many nonconvex problems of interest possess a favorable structure for optimization, in the sense that saddle points can be escaped efficiently by appropriate algorithms. This strict saddle property has been extensively used in data science to derive good properties for first-order algorithms, such as convergence to second-order critical points. However, the analysis and the design of second-order algorithms in the strict saddle setting have received significantly less attention. In this paper, we consider second-order trust-region methods for a class of strict saddle functions defined on Riemannian manifolds. These functions exhibit (geodesic) strong convexity around minimizers and negative curvature at saddle points. We show that the standard trust-region method with exact subproblem minimization finds an approximate local minimizer in a number of iterations that depends logarithmically on the accuracy parameter, which significantly improves known results for general nonconvex optimization. We also propose an inexact variant of the algorithm that explicitly leverages the strict saddle property to compute the most appropriate step at every iteration. Our bounds for the inexact variant also improve over the general nonconvex case, and illustrate the benefit of using strict saddle properties within optimization algorithms. Keywords: Riemannian optimization, strict saddle function, second-order method, complexity guarantees

Computing second-order points under equality constraints: revisiting Fletcher's augmented Lagrangian

We address the problem of minimizing a smooth function under smooth equality constraints. Under regularity assumptions on the feasible set, we consider a smooth exact penalty function known as Fletcher's augmented Lagrangian. We propose an algorithm to minimize the penalized cost function which reaches $\varepsilon$-approximate second-order critical points of the original optimization problem in at most $\mathcal{O}(\varepsilon^{-3})$ iterations. This improves on current best theoretical bounds. Along the way, we show new properties of Fletcher's augmented Lagrangian, which may be of independent interest

Sciences et langues au Moyen Âge – Wissenschaften und Sprachen im Mittelalter

Le recueil présenté sous ce titre bilingue est le reflet des journées d’étude de l’atelier franco-allemand qui s’est tenu à la Sorbonne en janvier 2009, et qui réunissait principalement des chercheurs de l’université de Heidelberg et de l’université de Paris-Sorbonne. Elles étaient consacrées à une thématique qui gagne en intérêt cette dernière décennie, à savoir l’expression des sciences au Moyen Âge, et la tension entre la langue savante, le latin, et les langues vernaculaires. Les contribu..

Sciences et langues au Moyen Âge – Wissenschaften und Sprachen im Mittelalter

Le recueil présenté sous ce titre bilingue est le reflet des journées d’étude de l’atelier franco-allemand qui s’est tenu à la Sorbonne en janvier 2009, et qui réunissait principalement des chercheurs de l’université de Heidelberg et de l’université de Paris-Sorbonne. Elles étaient consacrées à une thématique qui gagne en intérêt cette dernière décennie, à savoir l’expression des sciences au Moyen Âge, et la tension entre la langue savante, le latin, et les langues vernaculaires. Les contribu..

The European single market: How far from completion?

In 2012, the European Single Market will celebrate its 20th anniversary. Thanks to the May 2010 Monti report and the release of the European Commission's 'Towards a Single Market Act' six months later, renewed scrutiny is being given to the market's achievements and failings over the previous two decades. In this issue's Forum, our authors analyse this progress from diverse viewpoints and draw different conclusions as to the future path to be taken

Small vertebrates running on uneven terrain : a biomechanical study of two differently specialised lacertid lizards

While running, small animals frequently encounter large terrain variations relative to their body size, therefore, terrain variations impose important functional demands on small animals. Nonetheless, we have previously observed in lizards that running specialists can maintain a surprisingly good running performance on very uneven terrains. The relatively large terrain variations are ofset by their capacity for leg adjustability that ensures a ‘smooth ride’ of the centre of mass (CoM). The question as to how the efect of an uneven terrain on running performance and locomotor costs difers between species exhibiting diverse body build and locomotor specializations remains. We hypothesise that specialized runners with long hind limbs can cross uneven terrain more efciently than specialized climbers with a dorso-ventrally fattened body and equally short fore and hind limbs. This study reports 3D kinematics using high-speed videos (325Hz) to investigate leg adjustability and CoM movements in two lacertid lizards (Acanthodactylus boskianus, running specialist; Podarcis muralis, climbing specialist). We investigated these parameters while the animals were running on a level surface and over a custommade uneven terrain. We analysed the CoM dynamics, we evaluated the fuctuations of the positive and negative mechanical energy, and we estimated the overall cost of transport. Firstly, the results reveal that the climbers ran at lower speeds on fat level terrain but had the same cost of transport as the runners. Secondly, contrary to the running specialists, the speed was lower and the energy expenditure higher in the climbing specialists while running on uneven terrain. While leg movements adjust to the substrates’ variations and enhance the stability of the CoM in the running specialist, this is not the case in the climbing specialist. Although their legs are kept more extended, the amplitude of movement does not change, resulting in an increase of the movement of the CoM and a decrease in locomotor efciency. These results are discussed in light of the respective (micro-)habitat of these species and suggest that energy economy can also be an important factor for small vertebrates

A method to derive satellite PAR albedo time series over first-year sea ice in the Arctic Ocean

Deriving sea ice albedo from spaceborne platforms is of interest to model the propagation of the photosynthetically available radiation (PAR) through Arctic sea ice. We show here that use of the Moderate Resolution Imaging Spectroradiometer (MODIS) operational surface reflectance satellite product to derive albedo in the PAR spectral range is possible. To retrieve PAR albedo from the remote sensing surface reflectance, we trained a predictive model based on a principal component analysis with in situ and simulated data. The predictive model can be applied to first-year sea ice surfaces such as dry snow, melting snow, bare ice and melt ponds. Based on in situ measurements and the prescribed atmospheric correction uncertainty, the estimated PAR albedo had a mean absolute error of 0.057, a root mean square error of 0.074 and an R2 value of 0.91. As a demonstration, we retrieved PAR albedo on a 9-km2 area over late spring and early summer 2015 and 2016 at a coastal location in Baffin Bay, Canada. On-site measurements of PAR albedo, melt pond fraction and types of precipitation were used to examine the estimated PAR albedo time series. The results show a dynamic and realistic PAR albedo time series, although clouds remained the major obstacle to the method. This easy-to-implement model may be used for the partitioning of PAR in the Arctic Ocean and ultimately to better understand the dynamics of marine primary producers.publishedVersio