647 research outputs found
Analysis of the maritime logistic system in Chile and the design of a parametric model to decision making
The internationalisation of investments and the globalisation of the markets have created a high level of competition among manufacturing and services companies which has transcended the competition among nations. In this environment, quality information and exact timing are the sole answers for generating comparative and competitive advantages with respect to other manufacturers and providers. Inspired by these challenges, Latin American countries have searched for ways to increase and diversify their exports in order to heighten their trade balance surpluses. This, in turn, helps them to overcome their debt problems and gain access to a better quality of life. With these criteria in mind, these countries have begun to join the economic aperture and globalisation processes. United by their common ethnic heritage, they are driven by the growing need to co-ordinate national and regional decisions in order to achieve a harmonic community development. The efficiency principle imposed by the present international trade scenario requires extreme attention to detail in the administration of production costs and in placing products on the market. Because a product's success is highly sensitive to cost and distribution methods, maritime transport and its associated systems require very specific management techniques. Those management techniques must take into account that as transport is a service it gives added value to the cargo. Thus, the management model, costs involved, planning processes, and area policies are topics of vital importance for achieving these nations' development objectives. The design of specific policies, both operational as well as for development (investments), should comply with certain minimum conditions. The resulting policies should satisfy integrally and harmoniously the requirements the State establishes in its general National Development Strategy. This strategy considers factors of monetary and trade uncertainty. States must be particularly careful to interpret changes, tendencies, circumstances and difficulties which emerge in the international markets they serve, correctly. Therefore, the purpose of this study is to analyse the existing maritime transport logistic system in Chile, beginning with the history of ports and economic development. Subsequently, this study will analyse all relevant information related to logistics and the lessons learnt during the process of modernization. For analytical purposes, the study establishes an evaluation area which has been represented by a "graph" built up from nodes and links.These symbolise the complex network of port systems, hinterlands, roads, railways and coastal shipping. Likewise, the links and nodes have direction, intensity and values that the study intends to describe and evaluate. Moreover, hinterlands are not as exclusive as they were before. Consequently, most of the port systems face a very competitive market in offering services for international hinterlands/foreland. Therefore, this thesis will conclude that at least some Latin American countries establish land bridges between them. There have been some studies about the land bridges, "inter-oceanic corridors" or "integration corridors" options in South America.The Pacific Ocean Basin and the APEC countries represent a huge market for those Atlantic countries which have products to export and import from that vast area of the globe. The existence of the main industrial site of South America running from the Atlantic side of South America to the Pacific Coast, which forms an "Industrial Banana", is the foundation of a massive demand to and from both coasts. The study evaluated the logistics system through different criteria, such as logistics, physical capacities, and economic, social, environmental and political considerations. Having established these criteria, the researcher can better evaluate the relevant parameters and variables to consider in the design of the parametric model.La internacionalizacion de las inversiones y la globalizacion de los mercados, han creado un alto nivel de competitividad entre los proveedores de manufactura o de servicios, lo que trasciende a la competitividad entre las naciones. En este escenario, la informacion de calidad y respuesta en tiempo real son la respuesta para generar ventajas comparativas y competitivas respecto de otros productores y proveedores. Inspirados en estos cambios, los paises Latinoamericanos han buscado formas como aumentar y diversificar sus exportaciones, con el proposito de incrementar sus balanzas comerciales. Esto les ayuda a sobrellevar sus problemas de deuda, accediendo a mejor calidad de vida. Con estos criterios en mente, los paises de la Region han accedido a los procesos de apertura economica y globalizacion de los mercados. Unidos por la herencia etnica comun, ven una creciente necesidad por la coordinacion de sus decisiones nacionales y regionales, de manera de alcanzar el desarrollo comun de manera harmonica. Los principios de eficiencia impuestos por el presente esquema de comercio internacional, requiren de una atencion especial en la gestion de los costos de produccion y en la colocacion de los productos en los mercados. Considerando que el exito del producto es sensible a su costo, los sistemas de distribucion y logistica requiren de tecnicas especificas de gestion. Por ello, los modelos de gestion, costos, procesos de planificacion y politicas sectoriales son de vital importancia para alcanzar los objetivos nacionales de desarrollo. El diseno de politicas sectoriales, tanto operacionales como de desarrollo (inversiones), deberian cumplir con los minimas condiciones para lograr su objetivo pais. Las politicas resultantes debieran satisfacer de manera integral y harmonica, los requirimientos que el Estado ha establecido en su Estrategia Nacional de Desarrollo. Dicha estrategia debe incluir las incertidumbres monetarias y de commercio. Los Estados deben ser particularmente cuidadosos para interpretar correctamente los cambios, tendencias, circunstancias y dificultades que emergen de los mercados internacionales que ellos sirven. Por lo indicado anteriormente, el proposito de esta tesis es analizar el sistema de logistica maritima en Chile, comenzando con la historia de sus puertos y desarrollo economico, posteriormente el analisis de la informacion relevante a logistica y las lecciones aprendidas durante el proceso de modernizacion economica. Con propositos analiticos, el estudio determino una zona fisica de evaluacion que esta representada por la "teoria de grafos". Esta simboliza la compleja red de puertos, hinterlands, caminos, ferrovias y transporte maritimo costero. Los nodos y sus enlaces tienen direccion, intensidad y valores que el estudio pretende evaluar y dimensionar. Mas aun, en la actualidad el hinterland de los puertos ha dejado de ser exclusivo, consecuentemente, los sistemas portuarios enfrentan una agresiva competencia para ofertar servicios a sus hinterland/foreland, por lo cual algunos paises latinoamericanos construyeron "puentes terrestres" entre ellos, el estudio indica algunas opciones de "puentes terrestres", "corredores inter-oceanicos" o "corredores de integracion" identificados en America del Sur. La cuenca del Pacifico y los paises APEC representan un mercado enorme para los paises de la costa Atlantica. La existencia de la principal area industrial de Sudamerica se configura entre el Atlantico y Pacifico, forma lo que el autor denomina como la "Banana Industrial", lo que origina una enorme demanda en los dos sentidos. El estudio evalua los sistemas desde diferentes criterios, tales como: sus capacidades fisicas y logisticas, sus consideraciones economicas, politicas, sociales, y medio ambientales. Una vez establesidos los criterios, el investigador puede identificar y evaluar de mejor forma los parametros y variables a considerar en el diseno del "modelo parametrico".Postprint (published version
Phylogeographic and morphometric studies on the Eurasian pygmy shrew Sorex minutus: insights into its evolutionary history and postglacial colonisation in Europe
Here, I investigate the phylogeography and morphology of the Eurasian pygmy shrew Sorex minutus, searching for significantly differentiated lineages, colonisation routes and demographic parameters that would explain the effects of the Quaternary glaciations on the current distribution of the species. I also explore the genetic and morphological diversity and origin of pygmy shrew populations in the British Isles, particularly focusing on Ireland and the Orkney islands. Mitochondrial and nuclear DNA markers were used for the phylogeographic analyses, and a geometric morphometrics approach was implemented on mandible and skull samples. There was an evident phylogeographic structure across Eurasia consistent with occurrence of southern glacial refugia, and there were two distinct lineages in Northern-Central Europe and near the Pyrenees supporting the existence of northern glacial refugia through the characteristics of their distribution and population expansion. Haplotypes from Britain belonged to these two northern lineages, with the Pyrenean lineage forming a peripheral ‘Celtic fringe’. I show that it is most likely that pygmy shrews on both Ireland and Orkney were introduced by humans from mainland British Celtic fringe rather than further afield, even though there is a haplotype found in Northern Spain identical to one in Ireland. Mandible size increased noticeably with decreasing latitude, but skulls showed no evident trend in size variation. Shape variation was significant but modest when analysing the sample divided into phylogeographical groups. However, the samples from different islands within the British Isles show that island evolution played an important role in morphological diversity, with mandible and skull shape divergence on small islands and low genetic diversity. These results notably expanded previous findings and indicate that S. minutus is an excellent model for understanding the effects of climate change on biological diversity, colonisation and differentiation in refugia, and island evolution, useful for the conservation of genetic and morphological diversity
Architectural and Management Strategies for the Design, Construction and Operation of Energy Efficient and Intelligent Primary Care Centers in Chile
Primary care centers are establishments with elevated social relevance and high operational
energy consumption. In Chile, there more than 628 family healthcare centers (CESFAM) have been
built in the last two decades and with plans for hundreds more in the next few years. We revised
the architecture, construction management and energy performance of five CESFAM centers to
determine possible instances of overall improvement. Staff was interviewed, and state documents
reviewed, which allowed the conceptualization of the architectonic and energy structure of the
centers, as well as the process of implementation. At the same time, energy simulations were done
for each one of the centers, controlling for different climates, construction solutions and orientations.
Our study revealed that strategies employed by the primary healthcare centers in Chile have aided a
progressive implementation of establishments with elevated costs and materialization times, as well
as neglect for climatic conditions. These energy evaluations show relevant and consistent impacts
of the architectural form and material conditions, especially in southern zones, demonstrating the
need to work with shared knowledge resources such as BIM. There is a clear necessity to define
technological, morphological and construction strategies specific to each climate zone in order to
achieve energetically efficient and intelligent healthcare establishments
A Granular Tabu Search Algorithm for a Real Case Study of a Vehicle Routing Problem with a Heterogeneous Fleet and Time Windows
Purpose: We consider a real case study of a vehicle routing problem with a heterogeneous fleet
and time windows (HFVRPTW) for a franchise company bottling Coca-Cola products in
Colombia. This study aims to determine the routes to be performed to fulfill the demand of the
customers by using a heterogeneous fleet and considering soft time windows. The objective is to
minimize the distance traveled by the performed routes.
Design/methodology/approach: We propose a two-phase heuristic algorithm. In the
proposed approach, after an initial phase (first phase), a granular tabu search is applied during the
improvement phase (second phase). Two additional procedures are considered to help that the
algorithm could escape from local optimum, given that during a given number of iterations there
has been no improvement.
Findings: Computational experiments on real instances show that the proposed algorithm is able
to obtain high-quality solutions within a short computing time compared to the results found by
the software that the company currently uses to plan the daily routes.
Originality/value: We propose a novel metaheuristic algorithm for solving a real routing
problem by considering heterogeneous fleet and time windows. The efficiency of the proposed approach has been tested on real instances, and the computational experiments shown its
applicability and performance for solving NP-Hard Problems related with routing problems with
similar characteristics. The proposed algorithm was able to improve some of the current solutions
applied by the company by reducing the route length and the number of vehicles.Peer Reviewe
Editorial
Este número de Biota Colombiana es un homenaje a Gustavo Kattan (1953-2020), y contiene seis artÃculos relacionados de una u otra forma con su trabajo de investigación y el de quienes fueron sus estudiantes, incluyendo un artÃculo del que él mismo es coautor. La diversidad de temas abordados por estos artÃculos es una muestra de los amplios intereses de este polifacético investigador. Es, también, una muestra del impacto duradero que tendrá su legado cientÃfico. Por esta razón, hemos querido abrir el número con el artÃculo Reexpedición Colombia: entender el pasado para empoderar acciones que fortalezcan el conocimiento y conservación de las aves, reseña de un proyecto que encarna, como pocos, su naturaleza visionaria.
Además de los artÃculos relacionados con Gustavo Kattan, y en concordancia con su visión amplia de la naturaleza, este número contiene artÃculos de diversos temas de botánica, zoologÃa y ecologÃa, de investigadores de Colombia y Ecuador, que son muestra del crecimiento y diversificación de la investigación biológica en la región
Nuevas especies y combinaciones en la Subtribu Wettiniinae (Palmae)
Con base en la revisión de la subtribu Wettiniinae se incluye el género Cafoblastus bajo el género Wettinia. Se hacen las nuevas combinaciones Wettinia aequalis, W. anomala, W. disticha, W. kalbreyeri, W. microcarpa y W. radiata. Se describen además cuatro especies nuevas: W. aequatorialis, W. lanata, W. minima y W. panamensis.Based on a revision of the subtribe Wettiniinae, the genus Catoblastus is lncluaed under Wettinia. The new combinations Wettinia aequalis W. anomala, W. distiche, W. kalbreyeri, W. microcarpa, and W.radiata are made. Four new species are described - w. aequatorialis, W. lanata, W. minima, and W. panamensis
Editorial
El presente número de Biota Colombiana cubre un amplio espectro de temas de la biodiversidad de Colombia y de áreas vecinas, incluyendo plantas, diversos grupos de invertebrados y de vertebrados, y un tema que, por fortuna, recibe cada dÃa más atención: la mortalidad de fauna silvestre en las carreteras. El incesante crecimiento de las actividades humanas y la expansión de redes de carreteras y ferrocarriles han fragmentado severamente las poblaciones de fauna silvestre, y el costo que representa para los animales el moverse entre los fragmentos es elevado, como lo muestran Adárraga y Gutiérrez en su artÃculo sobre la mortalidad de vertebrados en la Troncaldel Caribe. Por esa razón hemos escogido este como nuestro tema de portada. Por otra parte, continúa la expansión de cobertura geográfica de la revista, que acoge cada vez más artÃculos de otros paÃses latinoamericanos. AsÃ, el presente número incluye tres artÃculos de investigadores ecuatorianos sobre variados aspectos de la biota de ese paÃs. Acorde con esa expansión geográfica, se da también un incremento del número de manuscritos sometidos en inglés, y en el presente número la mitad de los artÃculos están en esa lengua. Esperamos que poco a poco los investigadores de Colombia y otros paÃses latinoamericanos entiendan la importancia de hacer accesibles sus investigaciones a una audiencia mundial, escribiendo sus trabajos en inglés. Continuamos con nuestros esfuerzos para que el tiempo de procesamiento de los manuscritos sea cada vez más breve, para lo cual esperamos seguir contando con el apoyo de los evaluadores, a quienes expresamos una vez más nuestro agradecimiento por ayudarnos a fortalecer nuestra revista
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