246 research outputs found
Risk, Institutions and Growth: Why England and Not China?
We analyze the role of risk-sharing institutions in transitions to modern economies. Transitions requires individual-level risk-taking in pursuing productivity-enhancing activities including using and developing new knowledge. Individual-level, idiosyncratic risk implies that distinct risk-sharing institutions – even those providing the same level of insurance – can lead to different growth trajectories if they differently motivate risk-taking. Historically, risk sharing institutions were selected based on their cultural and institutional compatibility and not their unforeseen growth implications. We simulate our growth model incorporating England’s and China’s distinct pre-modern risk-sharing institutions. The model predicts a transition in England and not China even with equal levels of risk sharing. Under the clan-based Chinese institution, the relatively risk-averse elders had more control over technological choices implying lower risk-taking. Focusing on non-market institutions expands on previous growth-theoretic models to highlight that transitions can transpire even in the absence of exogenous productivity shocks or time-dependent state variables. Recognizing the role of non-market institutions in the growth process bridges the view that transitions are due to luck and the view that transitions are inevitable. Transitions transpire when ‘luck’ creates the conditions under which economic agents find it beneficial to make the choices leading to positive rates of technological change. Luck came in the form of historical processes leading to risk-sharing institutions whose unintended consequences encouraged productivity-enhancing risk-taking.institutions, risk, growth, development
BORPH: operating system support on the NetFPGA platform
This paper introduces the concepts behind BORPH, an operating system for reconfigurable computers. The porting and implementation of this operating system for the NetFPGA platform, as well as the tool flow integration are described.postprintThe 2nd North American NetFPGA Developers Workshop 2010, Stanford, CA., 12-13 August 2010
Cork oak (Quercus suber L.) wood hygroscopic properties and dimentional stability
Cork oak (Quercus suber L.) wood has a potential for high value uses because of its strength and aesthetic properties
but one obstacle is the lack of knowledge of the wood-water relations. Variations in wood equilibrium moisture content,
density and dimensions were studied at air temperatures of 22°C and 27°C (representing acclimatized homes and summer
non-acclimatized homes, respectively) varying from 80% to 30% of relative humidity.
For indoor uses (22-27°C, 50-65% of relative humidity), the wood equilibrium moisture content ranged 12-17% and
these values are recommended for the final commercial drying of cork oak wood. The fibre saturation point averaged
27%. Total volumetric shrinkage at 22°C-27°C averaged 12%, the linear shrinkage 8.1-8.5% and 3.6-3.6%, respectively
in tangential and radial directions. Anisotropy averaged 2.3. Wood density at 12% moisture content ranged 0.63
to 0.67 g/cm3. The higroscopicity obtained was 0.003. The average tangential differential shrinkage was 0.32 for both
temperatures and the average radial differential shrinkage was 0.14 and 0.15, at 22°C and 27°C respectively. The
shrinkage factor was 0.90 cm3/g and 0.82 cm3/g, at 22°C and 27°C respectively. Differences between temperatures
were only statistically significant at 80-70% of relative humidity
Reconfigurable Logic Embedded Architecture of Support Vector Machine Linear Kernel
Support Vector Machine (SVM) is a linear binary classifier that requires a kernel function to handle non-linear problems. Most previous SVM implementations for embedded systems in literature were built targeting a certain application; where analyses were done through comparison with software im- plementations only. The impact of different application datasets towards SVM hardware performance were not analyzed. In this work, we propose a parameterizable linear kernel architecture that is fully pipelined. It is prototyped and analyzed on Altera Cyclone IV platform and results are verified with equivalent software model. Further analysis is done on determining the effect of the number of features and support vectors on the performance of the hardware architecture. From our proposed linear kernel implementation, the number of features determine the maximum operating frequency and amount of logic resource utilization, whereas the number of support vectors determines the amount of on-chip memory usage and also the throughput of the system
Propiedades higroscópicas y de estabilidad dimensional de madera de alcornoque (Quercus suber L.)
Cork oak (Quercus suber L.) wood has a potential for high value uses because of its strength and aesthetic properties but one obstacle is the lack of knowledge of the wood-water relations. Variations in wood equilibrium moisture content, density and dimensions were studied at air temperatures of 22°C and 27°C (representing acclimatized homes and summer non-acclimatized homes, respectively) varying from 80% to 30% of relative humidity. For indoor uses (22-27°C, 50-65% of relative humidity), the wood equilibrium moisture content ranged 12-17% and these values are recommended for the final commercial drying of cork oak wood. The fibre saturation point averaged 27%. Total volumetric shrinkage at 22°C-27°C averaged 12%, the linear shrinkage 8.1-8.5% and 3.6-3.6%, respectively in tangential and radial directions. Anisotropy averaged 2.3. Wood density at 12% moisture content ranged 0.63 to 0.67 g/cm3. The higroscopicity obtained was 0.003. The average tangential differential shrinkage was 0.32 for both temperatures and the average radial differential shrinkage was 0.14 and 0.15, at 22°C and 27°C respectively. The shrinkage factor was 0.90 cm3/g and 0.82 cm3/g, at 22°C and 27°C respectively. Differences between temperatures were only statistically significant at 80-70% of relative humidity.La madera de alcornoque tiene potencial para usos de alto valor debido a su resistencia y propiedades estéticas, pero presenta un obstáculo como es la falta de conocimiento de las relaciones agua-madera. Se han estudiado las variaciones en el contenido de humedad de equilibrio de la madera, la densidad y las dimensiones a temperaturas del aire de 22°C y 27°C (que representa casas climatizadas y casas de verano no aclimatadas, respectivamente) variando entre 80% a 30% de humedad relativa. Para usos interiores (22-27° C, 50-65% de humedad relativa), el equilibrio de humedad de la madera osciló entre el 12-17% y se recomiendan estos valores para el secado final de la madera comercial de alcornoque. El punto de saturación de la fibra promedio es del 27%. La contracción volumétrica total a 22°C-27°C en promedio es de un 12%, la contracción lineal varía entre 8.1-8.5% y 3.6-3.6%, respectivamente en direcciones tangenciales y radiales. La anisotropía promedio fue de 2,3. La densidad de la madera con un contenido de humedad del 12% varió entre 0,63 a 0,67 g/cm3. La higroscopicidad obtenida fue de 0,003. La contracción diferencial tangencial promedio fue de 0,32 para ambas temperaturas y la contracción radial diferencial promedio fue de 0,14 y 0,15, a 22°C y 27°C respectivamente. El factor de contracción fue de 0,90 cm3/g y 0,82 cm3/g, a 22°C y 27°C respectivamente. Las diferencias entre las temperaturas fueron estadísticamente significativas sólo al 80-70% de humedad relativa
A Survey on FPGA-Based Heterogeneous Clusters Architectures
In recent years, the most powerful supercomputers have already reached megawatt power consumption levels, an important issue that challenges sustainability and shows the impossibility of maintaining this trend. To this date, the prevalent approach to supercomputing is dominated by CPUs and GPUs. Given their fixed architectures with generic instruction sets, they have been favored with lots of tools and mature workflows which led to mass adoption and further growth. However, reconfigurable hardware such as FPGAs has repeatedly proven that it offers substantial advantages over this supercomputing approach concerning performance and power consumption. In this survey, we review the most relevant works that advanced the field of heterogeneous supercomputing using FPGAs focusing on their architectural characteristics. Each work was divided into three main parts: network, hardware, and software tools. All implementations face challenges that involve all three parts. These dependencies result in compromises that designers must take into account. The advantages and limitations of each approach are discussed and compared in detail. The classification and study of the architectures illustrate the trade-offs of the solutions and help identify open problems and research lines
An Approach to Manage Reconfigurations and Reduce Area Cost in Hard Real-Time Reconfigurable Systems
This article presents a methodology to build real-time reconfigurable systems that ensure that all the temporal constraints of a set of applications are met, while optimizing the utilization of the available reconfigurable resources. Starting from a static platform that meets all the real-time deadlines, our approach takes advantage of run-time reconfiguration in order to reduce the area needed while guaranteeing that all the deadlines are still met. This goal is achieved by identifying which tasks must be always ready for execution in order to meet the deadlines, and by means of a methodology that also allows reducing the area requirements
Economic aspects of FPGA technology
En este PFC se ha recogido y analizado diversa información acerca de la
tecnología de Xilinx. Incluyendo los datasheets de Xilinx notas del E.E.
Times, informes financieros, y artículos de internet. Todos los datos se han
unificado en unas ciento cincuenta figuras y tablas. Además, se han
revisado los proceedings de la conferencia FPL desde 1991 (la primera en
Oxford) hasta 2013 (el último en Porto).In this PFC, diverse information about Xilinx technology has been
collected and analyzed. It includes Xilinx datasheets, notes on E.E. Times,
financial reports, and Internet articles. All the data have been unified in
around one hundred and fifty figures and tables. In addition, FPL
proceedings from 1991 (the first in Oxford) to 2013 (the last in Porto)
have been revised
The conservation of panel paintings and related objects
Until the early 17th century almost all portable paintings were created on wood
supports, including masterpieces by famous painters, ranging from Giotto to Dürer
to Rembrandt. The structural conservation of these paintings requires specific
knowledge and skills as the supports are susceptible to damage caused by unstable
environmental conditions.
Unfortunately, past structural interventions often caused significant damage due
to insufficient knowledge of the behaviour of the wood panels, glue and paint
layers. Over the last fifty years, the field has developed treatment strategies based
on interdisciplinary collaboration and on the knowledge of specialist conservators.
Most current conservation protocols rely on empirical knowledge of conservators
and are not necessarily based on a scientific understanding of the nature and
behaviour of wood and paint layers.
In order to move the field forward, it is imperative to strengthen scientific research
into the production methods, ageing and future behaviour of panel paintings,
being an intricate interplay between different materials. A deeper understanding of
the processes that adversely affect panel paintings over time will contribute to the
improved care and conservation of these artworks.
The Netherlands Organisation for Scientific Research (NWO) and the Rijksmuseum
Amsterdam brought together a group of experts from different disciplines to
recommend specific areas in the field that would benefit from systematic research.
The experts concluded that targeted interdisciplinary research projects are key to
understanding the behaviour of panel paintings and help conservators make better
informed decisions. Research into chemical and physical properties of wood, glue
and paint layers should be combined with an evaluation of past and current
conservation treatments. Research should also consider the history of the object,
studio practice, conservation history and thoughts on long-term impact of
treatments
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