Search results for "float"

Second-order hydrodynamic effects on the response of three semisubmersible floating offshore wind turbines

2020

Abstract Floating structures have become the most feasible solution for supporting wind turbines when offshore wind project move to deeper water. In this paper, a hydrodynamic analysis of three different semisubmersible floating offshore wind turbines is carried out including second-order hydrodynamic effects. The three examined platforms are V-shaped semisubmersible, Braceless semisubmersible and OC4-DeepCwind semisubmersible and are used to support the NREL 5 MW reference wind turbine. The main objective of the present study is to investigate and compare the hydrodynamic response of the three different semisubmersible floaters in two water depths (100 m, and 200 m) under different load co…

Transient response of a TLP-type floating offshore wind turbine under tendon failure conditions

2021

Abstract Among various types of floating offshore wind turbines (FOWTs), the tension leg platform (TLP) floating wind turbines have relatively small motions due to stiff tendons. Similar to TLP applications in the offshore industry, tendon failure may lead to deteriorated stability and large transient responses, which should be considered as part of accidental limit state (ALS) checks at the design stage of the TLP FOWTs. This paper takes the WindStar TLP system as a representative and investigates the transient effects of one-tendon failure on the system responses. A coupled numerical model is first established using the aero-hydro-servo-elastic simulation tool FAST. Subsequent numerical s…

STUDY REGARDING THE EVOLUTION OF THE FINANCIAL BALANCE IN THE PHARMACEUTICAL INDUSTRY

2015

Abstract This article aims at analysing the financial balance within the global pharmaceutical industry, starting from the assumption that „In the pharmaceutical industry there is sufficient liquidity to cover payment obligations”. The analysed companies are part of the exclusive group comprising the top 20 global companies, e.g. GlaxoSmithKline, Merck & Co., Sanofi-Aventis and Bayer. The research conducted is based on an analysis over time of the relationship between floating assets, floating assets requirement and net cash from 2006 to 2013, and highlights the main developments of the indicators before the onset of the financial and economic crisis and after its outbreak.

Float zone single crystals for testing rods, pulled under electron beam heating

2019

Propuesta de elaboración de un glosario bilingüe (español-francés) en línea de términos arquitectónicos

2019

[ES] En estas páginas se expone cómo constituir un glosario técnico (español-francés) en línea de términos sobre Arquitectura Flotante. A partir de un corpus de documentos, en francés y en español, publicados en Internet, se procederá a la localización y reunión de términos específicos de este campo en cada una de las lenguas mencionadas; a la descripción de los distintos tipos de unidades léxicas propias de este ámbito; y la presentación de las correspondencias traductológicas entre ambas lenguas o, en su defecto, a la propuesta de equivalencias definitorias. Este trabajo constituye una aportación al estudio de la traducción técnica en el campo de la Arquitectura.

A dynamic program analysis to find floating-point accuracy problems

2012

Programs using floating-point arithmetic are prone to accuracy problems caused by rounding and catastrophic cancellation. These phenomena provoke bugs that are notoriously hard to track down: the program does not necessarily crash and the results are not necessarily obviously wrong, but often subtly inaccurate. Further use of these values can lead to catastrophic errors.In this paper, we present a dynamic program analysis that supports the programmer in finding accuracy problems. Our analysis uses binary translation to perform every floating-point computation side by side in higher precision. Furthermore, we use a lightweight slicing approach to track the evolution of errors.We evaluate our…

Efficient and portable acceleration of quantum chemical many-body methods in mixed floating point precision using OpenACC compiler directives

2016

It is demonstrated how the non-proprietary OpenACC standard of compiler directives may be used to compactly and efficiently accelerate the rate-determining steps of two of the most routinely applied many-body methods of electronic structure theory, namely the second-order M{\o}ller-Plesset (MP2) model in its resolution-of-the-identity (RI) approximated form and the (T) triples correction to the coupled cluster singles and doubles model (CCSD(T)). By means of compute directives as well as the use of optimized device math libraries, the operations involved in the energy kernels have been ported to graphics processing unit (GPU) accelerators, and the associated data transfers correspondingly o…

LARGE-SCALE SIMULATIONS IN CONDENSED MATTER PHYSICS —THE NEED FOR A TERAFLOP COMPUTER

1992

The introduction of vector processors {“supercomputers” with a performance in the range of 109 floating point operations (1 GFLOP) per second} has had an enormous impact on computational condensed matter physics. The possibility of a substantially enhanced performance by massively parallel processors (“teraflop” machines with 1012 floating point operations per second) will allow satisfactory treatment of a large range of important scientific problems which have to a great extent thus far escaped numerical resolution. The present paper describes only a few examples (out of a long list of interesting research problems!) for which the availability of “teraflops” will allow spectacular progres…

Hardware-efficient matrix inversion algorithm for complex adaptive systems

2012

This work shows an FPGA implementation for the matrix inversion algebra operation. Usually, large matrix dimension is required for real-time signal processing applications, especially in case of complex adaptive systems. A hardware efficient matrix inversion procedure is described using QR decomposition of the original matrix and modified Gram-Schmidt method. This works attempts a direct VHDL description using few predefined packages and fixed point arithmetic for better optimization. New proposals for intermediate calculations are described, leading to efficient logic occupation together with better performance and accuracy in the vector space algebra. Results show that, for a relatively s…

The Discursive Constitution of a World-Spanning Region and the Role of Empty Signifiers: The Case of Francophonia

2007

The cultural turn in political science, history, and political geography has opened new perspectives on the division of the world into geographic entities. Nation-states, regions, districts, etc., are no longer qualified as quasi-natural objects based upon intrinsic qualities but, rather, as contingent results of social or accordingly discursive processes. The Organisation Internationale de la Francophonie (OIF) defines Francophonia as an “geocultural space” (espace geoculturel) and an international community of more than 50 states. In this contribution, the concept of political communities as “imagined communities” and the advancements of discourse theory by Laclau and Mouffe are used in o…