10,747 research outputs found
Pre-processing method for software synthesis of synchronous dataflow networks
voorzitter: prof. dr. Lex Bijlsma, begeleider: dr. Bastiaan Heerenthis thesis describes the progress that has been realized on the software synthesis of functional specifications of real-time signal processing applicatons that run on multi-processor architecture
Quantitative resistance can lead to evolutionary changes in traits not targeted by the resistance QTLs
This paper addresses the general concern in plant pathology that the introduction of quantitative resistance in the landscape can lead to increased pathogenicity. Hereto, we study the hypothetical case of a quantitative trait loci (QTL) acting on pathogen spore production per unit lesion area. To regain its original fitness, the pathogen can break the QTL, restoring its spore production capacity leading to an increased spore production per lesion. Or alternatively, it can increase its lesion size, also leading to an increased spore production per lesion. A data analysis shows that spore production per lesion (affected by the resistance QTL) and lesion size (not targeted by the QTL) are positively correlated traits, suggesting that a change in magnitude of a trait not targeted by the QTL (lesion size) might indirectly affect the targeted trait (spore production per lesion). Secondly, we model the effect of pathogen adaptation towards increased lesion size and analyse its consequences for spore production per lesion. The model calculations show that when the pathogen is unable to overcome the resistance associated QTL, it may compensate for its reduced fitness by indirect selection for increased pathogenicity on both the resistant and susceptible cultivar, but whereby the QTLs remain effective
Large deviations for ideal quantum systems
We consider a general d-dimensional quantum system of non-interacting
particles, with suitable statistics, in a very large (formally infinite)
container. We prove that, in equilibrium, the fluctuations in the density of
particles in a subdomain of the container are described by a large deviation
function related to the pressure of the system. That is, untypical densities
occur with a probability exponentially small in the volume of the subdomain,
with the coefficient in the exponent given by the appropriate thermodynamic
potential. Furthermore, small fluctuations satisfy the central limit theorem.Comment: 28 pages, LaTeX 2
Pest-predator spatial relationships in winter rape: implications for integrated crop management
Douglas Warner, Les J Allen-Williams, Andrew W Ferguson, and Ingrid H Williams, 'Pest–predator spatial relationships in winter rape: implications for integrated crop management', Pest Management Science, Vol. 56 (11): 977-982, November 2000, doi: 10.1002/1526-4998(200011)56:113.0.CO;2-U. Copyright © 2000 Society of Chemical IndustryThe brassica pod midge (Dasineura brassicae) is an important and widespread pest of winter and spring oilseed rape throughout Europe. Pods infested by D brassicae larvae split prematurely, releasing seeds, and the larvae drop to the soil into which they burrow to pupate. At this stage in its lifecycle D brassicae is potentially vulnerable to predation by carabid beetles foraging on the soil surface. This is the first study in the UK to focus on carabid beetles as predators of D brassicae in the oilseed rape crop. The spatio-temporal distributions of larvae of D brassicae dropping to the soil from the crop canopy and of adult carabid beetles active on the soil surface were analysed in two consecutive years. Insect samples were collected from spatially referenced sampling points across each crop. Counts of insects were mapped and analysed, and the degree of spatial association between predator and prey determined using Spatial Analysis by Distance Indices (SADIE). Carabid species abundant and active during peak drop of first generation D brassicae larvae included Agonum dorsale, Amara similata, Harpalus rufipes and Nebria brevicollis. The larvae of D brassicae had a marked edge distribution within the crop. SADIE analysis revealed significant spatial association between larvae of D brassicae and adult H rufipes (P <0.05) in 1998, but not with adults of A dorsale, A similata or N brevicollis. In 1999, there was strong spatial association only between larvae of D brassicae and adult A dorsale (P <0.01). Aggregation of N brevicollis adults occurred in some areas of greatest D brassicae larval counts in 1999, but overall spatial association was not signi®cant. The distributions are discussed in terms of their relevance to integrated crop management (ICM) strategies and spatial targeting of insecticides.Peer reviewe
MATCHED ARCHITECTURES FOR SIGNAL PROCESSING AND CONTROL
Fast processing environments for real-time data acquisition, data processing and control applications may be realised using very different architectures. State of the art systems generally employ multiprocessors and parallel processing having a dedicated architecture such as systolic arrays to support computation-intensive signal processing tasks such as, for instance, convolution, filtering, FFT. etc. Mostly, general purpose rather than application driven architectures are used whenever possible and the available literature is heavily concentrated on the first configuration.
At TPD-TNO, the research emphasis is on application driven architectures. and the objectives for the so-called 'matched' architecture designs are:
- Capability for a wide range of sizes, starting from small systems. The objective here is design for scalability
- Design for systems to be used in harsh environments
- Design for minimum connectivity. reduced communication bandwidth, incorporation of dedicated preprocessing. multibus systems, etc.
The real-time behaviour of general purpose architectures is not sufficiently predictable and they are not designed to perform acquisition tasks or data-intensive processing with high performance. Matched architectures, on the contrary, are designed for well defined applications and optimized for each application,
The key effort in matched architecture research is directed towards efficiently mapping algorithms to processing steps in hardware (and software) architectures. Essentially. the design process is iterative
Tin dioxide sol-gel derived thin films deposited on porous silicon
Undoped and Sb-doped SnO2 sol¿gel derived thin films have been prepared for the first time from tin (IV) ethoxide precursor and SbCl3 in order to be utilised for gas sensing applications where porous silicon is used as a substrate. Transparent, crack-free and adherent layers were obtained on different types of substrates (Si, SiO2/Si). The evolution of the Sn¿O chemical bonds in the SnO2 during film consolidation treatments was monitored by infrared spectroscopy. By energy dispersive X-ray spectroscopy performed on the cross section of the porosified silicon coupled with transmission electron microscopy, the penetration of the SnO2 sol¿gel derived films in the nanometric pores of the porous silicon has been experimentally proved
До ювілею В.П. Кухаря
26 січня 2012 року виповнилося сімдесят років видатному вченому в галузі біоорганічної, органічної та елементоорганічної хімії, засновнику нового наукового напряму хімії біорегуляторних процесів, відомому досліднику екологічних та ресурсоощадливих аспектів енергетики, нафтопереробки і нафтохімії, директору Інституту біоорганічної хімії та нафтохімії Національної академії наук України, академіку НАН України Валерію Павловичу Кухарю
Direct frequency comb spectroscopy of trapped ions
Direct frequency comb spectroscopy of trapped ions is demonstated for the
first time. It is shown that the 4s^2S_(1/2)-4p^2P_(3/2) transition in calcium
ions can be excited directly with a frequency comb laser that is upconverted to
393 nm. Detection of the transition is performed using a shelving scheme to
suppress background signal from non-resonant comb modes. The measured
transition frequency of f=761 905 012.7(0.5) MHz presents an improvement in
accuracy of more than two orders of magnitude.Comment: 4 pages, 5 figur
A Service of zbw Leibniz-Informationszentrum Wirtschaft Leibniz Information Centre for Economics
Standard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. Terms of use: Documents in Abstract This paper investigates regulation by auctions of private supply of congestible infrastructures in two networks settings: 1) two serial facilities, where the consumer has to use both in order to consume; and 2) two parallel facilities that are imperfect substitutes. There are four market structures: a monopoly and 3 duopolies that differ in how firms interact. The effects of an auction depend on what the bidders compete. With a transfer auction, the bidders compete on how much money they transfer to the government. This auction leads to the same outcome as the game without an auction (for a given market structure), since this gives the maximum profit to transfer. An auction on the capacity of a facility leads to an even lower welfare than no auction, because firms set very high capacities and usage fees. Conversely, an auction on the generalised price or number of users leads to the first-best outcome. Moreover, these two auctions are robust: they attain the first-best regardless of whether the facilities are auctioned off to a single firm or to two, and for all market and network structures. On the contrary, the performances (relative to the firstbest) of the transfer and capacity auctions strongly depend on these considerations
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