611 research outputs found
Mr. O. A. Larrazolo answers the Herald's published interview of Republican State Chairman, O.L. Phillips
No full textMr. O. A. Larrazolo answers the Herald's published interview of Republican State Chairman, O.L. Phillips, in relation to conferences held by him with Independent Republican
The city of the crescent; with pictures of Harem life, or The turks in 1854. By Gordon O.L. Gordon Trenery, Esq. Author of "the morning Land" etc. etc. In two volumes London΄Charles J. skeet 10, king William street, Charing cross. 1855.
No full textPreface: by Trenery CordonDedication:Content description: Detailed contentsIllustration: 2 (Views ,)Pagination: PP16+303P, PP10+309+1PPVolumes: 2Text Genre:ProseEpilogue: as conclusion at the last chapterIllustration: 2 (τοπία ,
An approximate solution of loaded hyperbolic equation with homogenios boundary conditions
No full textО.Л. Бозиев,
Институт информатики и проблем регионального управления
Кабардино-Балкарского научного центра РАН, г. Нальчик, Российская Федерация
E-mail: [email protected]. O.L. Boziev
Institute of Computer Science and Problems of Regional Management of KBSC
of the Russian Academy of Sciences, Nal'chik, Russian Federation
E-mail: [email protected]Получена формула приближенного решения начально-краевой задачи
для нагруженного гиперболического уравнения, для нахождения которого
используется априорная оценка решения поставленной задачи. The article proposes a method for solving hyperbolic equation with a spatial variable integral of the
natural powers of the unknown function modulus, whereby it is loaded. The author considers an initial
boundary value problem with homogeneous boundary conditions. Scalar products of the equation by
various functionals and subsequent conversions make it possible to obtain a priori estimates of solutions
of the problem in various spaces. By successive integration over the spatial variable the reduction to an
ordinary differential equation associated with the initial one is produced. Its approximate solution is
sought using a priori estimates that are obtained. Found function leads to the formula that expresses the
approximate solution to the original problem through the right parts of the initial conditions
How Al Gentry Changed Tropical Ecology
No full textAlwyn Gentry’s ecological legacy is rich and vibrant. It comes from his drive to revolutionize plant identification and to apply these innovations to understand tropical forests both in detail and as a whole. It stems too from his passion for plants and forests, and the attention he gave those who shared his love for the natural world. Here I explore the impacts of Gentry’s approach and findings on tropical ecological science today. The big challenges that always face those wanting to understand tropical forests are their high diversity and the fact that most of the time plants here are sterile, while identification depends on reproductive structures. Because flowers are least accessible for the canopy trees and lianas that dominate tropical forests, this affects our ability to measure biodiversity, understand it, and monitor its persistence over time. Gentry has helped to make all these possible. Thanks to his innovations in plant identification and his vision in applying them to whole forests, tropical floristic inventory and ecological monitoring have become almost commonplace and, crucially, replicated across time and space. We now know which forests are most diverse, and why, and how their composition changes over space, climate, and soil. Gentry’s insights and methods help us better understand where conservation needs to focus, how forest people use their environment, and how global changes impact the biodiversity and carbon of Earth’s most complex ecosystems. Finally, his influence includes lasting impacts not simply on what we have learned, but also on how we do our science, and even on who does it
Robust model-based optimization of evacuation guidance
No full textLarge scale disasters, such as floods and fires, cause many casualties. This risk of casualties is reduced by evacuating the people from the threatened region. By guiding these people, i.e. instructing them when and where to go, the efficiency of the evacuation is increased. This means that, for example, the time needed for the evacuation is reduced. This thesis discusses the literature on optimization methods for car-based evacuation guidance. While many optimization methods are developed, the attention for uncertainty and compliance behavior in these methods is limited. This while these factors are of great importance for evaluating guidance in a realistic way. These findings are the reason to ask the following question: How can evacuation guidance be optimized in an efficient way, while incorporating uncertainty and compliance behavior? This thesis answers this question by formulating problems, presenting solution approaches and analyzing the results of case studies. The problem formulations contain decision variables representing guidance, consisting of departure time, route, and destination instructions for all evacuees. An objective function expresses the performance of this guidance. A travel behavior model and a traffic propagation model are included in the problem formulation to evaluate the guidance resulting in the performance value. The formulations and approaches are flexible with respect to the modeling assumptions. This is important because of the high degree of development of evacuation models. The first specific problem formulation presented in this thesis incorporates compliance behavior in the optimization of evacuation guidance. This problem is solved by a metaheuristic based on ant colony optimization. The method is applied to develop evacuation guidance for a hypothetical flood of part of The Netherlands. This case study shows that the optimized guidance increases the evacuation efficiency compared to no guidance or guidance developed by simple rules. This can be explained by the spread of travelers over time and space. The case study also shows that the solution approach results in a solution which effectiveness is close to the effectiveness of the optimal solution. The problem formulation is extended such that all kinds of uncertainty, like uncertainty in the demand, the behavior and the capacity, can be incorporated. This formulation is based on scenarios, which are representations of the uncertainty. Two procedures to select these scenarios are proposed, i.e. a deterministic procedure which results in a set of scenarios that is constant over the iterations of the solution approach, and a stochastic procedure that results in varying scenarios over the iterations. A case study shows the usefulness of incorporating uncertainty in the evacuation problem. For most cases holds that the efficiency of the evacuation increases when uncertainty is incorporated. The case study also shows that incorporating uncertainty is computationally demanding. Solving the evacuation problem is computationally expensive because of a high number of decision variables and high evaluation costs. A fixed-point approach is presented that efficiently optimizes evacuation guidance, in particular route guidance. This approach decomposes the original problem into simpler problems that are iteratively solved resulting in an approximate solution to the original problem. This approach overcomes the difficulties associated with the original problem. A case study shows that the fixed-point approach substantially speeds up the optimization of route guidance, while maintaining a comparable effectiveness of the resulting guidance. This thesis gives new insights in how beneficial evacuations are and how realistic plans can be optimized efficiently. The presented methods are ready for use in practice regarding the development of car-based evacuation guidance. Guidance can be optimized and, if available, it can be compared with existing plans. The guidance will be part of a broader plan that includes, for example, evacuation by public transport and communication and operation strategies.Transport & PlanningCivil Engineering and Geoscience
Sensing Forests Directly: The Power of Permanent Plots
No full textThe need to measure, monitor, and understand our living planet is greater than ever. Yet, while many technologies are applied to tackle this need, one developed in the 19th century is transforming tropical ecology. Permanent plots, in which forests are directly sensed tree-by-tree and species-by-species, already provide a global public good. They could make greater contributions still by unlocking our potential to understand future ecological change, as the more that computational and remote technologies are deployed the greater the need to ground them with direct observations and the physical, nature-based skills of those who make them. To achieve this requires building profound connections with forests and disadvantaged communities and sustaining these over time. Many of the greatest needs and opportunities in tropical forest science are therefore not to be found in space or in silico, but in vivo, with the people, places and plots who experience nature directly. These are fundamental to understanding the health, predicting the future, and exploring the potential of Earth’s richest ecosystems. Now is the time to invest in the tropical field research communities who make so much possible
Cheap red wine
No full text'Cheap Red Wine’ is a poem that plays with the intimacy felt sometimes between readers and their favourite authors, in this case Baudelaire. The feeling that some authors -even those long dead-somehow are with us, somehow know us better than we know ourselves. That if we listen intently enough, the words will be embodied and we can converse with the author we care about. Of course, as the title suggests, a little red wine can help things along
Functional composition of the Amazonian tree flora and forests
No full textPlants cope with the environment by displaying large phenotypic variation. Two spectra of global plant form and function have been identified: a size spectrum from small to tall species with increasing stem tissue density, leaf size, and seed mass; a leaf economics spectrum reflecting slow to fast returns on investments in leaf nutrients and carbon. When species assemble to communities it is assumed that these spectra are filtered by the environment to produce community level functional composition. It is unknown what are the main drivers for community functional composition in a large area such as Amazonia. We use 13 functional traits, including wood density, seed mass, leaf characteristics, breeding system, nectar production, fruit type, and root characteristics of 812 tree genera (5211 species), and find that they describe two main axes found at the global scale. At community level, the first axis captures not only the ‘fast-slow spectrum’, but also most size-related traits. Climate and disturbance explain a minor part of this variance compared to soil fertility. Forests on poor soils differ largely in terms of trait values from those on rich soils. Trait composition and soil fertility exert a strong influence on forest functioning: biomass and relative biomass production
Increasing turnover through time in tropical forests
No full textTree turnover rates were assessed at 40 tropical forest sites. Averaged across inventoried forests, turnover, as measured by tree mortality and recruitment, has increased since the 1950's, with an apparent pantropical acceleration since 1980. Among 22 mature forest sites with two or more inventory periods, forest turnover also increased. The trend in forest dynamics may have profound effects on biological diversity
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