344 research outputs found

    Fuzzified iterative algorithms for performance driven low powerVLSI placement

    Get PDF
    In this paper we employ fuzzified simulated evolution and stochastic evolution algorithms for VLSI. standard cell placement targeting low power dissipation and high performance. Due to the imprecise nature of design information at the placement stage, the various objectives and constraints are expressed in fuzzy domain. The search is made to evolve towards a vector of fuzzy goals. The proposed algorithms are compared with genetic algorith

    Fuzzified iterative algorithms for performance driven low powerVLSI placement

    Get PDF
    In this paper we employ fuzzified simulated evolution and stochastic evolution algorithms for VLSI. standard cell placement targeting low power dissipation and high performance. Due to the imprecise nature of design information at the placement stage, the various objectives and constraints are expressed in fuzzy domain. The search is made to evolve towards a vector of fuzzy goals. The proposed algorithms are compared with genetic algorith

    Fuzzy simulated evolution for power and performance optimization ofVLSI placement

    Get PDF
    In this paper, an algorithm for VLSI standard cell placement for low power and high performance design is presented. This is a hard multiobjective combinatorial optimization problem with no known exact and efficient algorithm that can guarantee finding a solution of specific or desirable quality. Approximation iterative heuristics such as simulated evolution (SE) are best suited to perform an intelligent search of the solution space. SE comprises three steps, evaluation, selection and allocation. Due to imprecise nature of design information at the placement stage, the various objectives and constraints are expressed in fuzzy domain. The search is made to evolve towards a vector of fuzzy goals. In this work, a new method to calculate membership in evaluation stage is proposed. Selection stage is also fuzzified and a new controlled fuzzy operator is introduced. The proposed heuristics is compared with genetic algorithm (GA) and the proposed fuzzy operator is compared with fuzzy ordered weighted averaging operator (OWA). Fuzzified SE (FSE) with controlled fuzzy operators was able to achieve better solution

    Egg parasitoids of the genus Trichogramma (Hymenoptera, Trichogrammatidae) in olive groves of the Mediterranean region

    Get PDF
    A survey of egg parasitoids of the genus Trichogramma (Hymenoptera, Trichogrammatidae) was carried out in olive groves in Portugal, Greece, Egypt, and Tunisia during the years 2002–2004. Parasitoids were obtained either by exposing sentinel eggs (Sitotroga cerealella Olivier or Ephestia kuehniella Zeller) on olive trees or by collecting eggs of lepidopterous olive pests. Parasitized egg samples were reared separately in the laboratory for emergence of parasitoids. These were further reared in separate lines and processed by morphological and molecular biology techniques for species characterization. The recorded fauna of Trichogramma parasitoids in olive groves was species poor and consisted of species mainly known from the Mediterranean region. Trichogramma bourarachae Pintureau and Babault was found in Tunisia and Egypt, T. cordubensis Vargas and Cabello, and T. euproctidis Girault in Egypt, Trichogramma cacoeciae Marchal in Portugal, Greece, Egypt, Tunisia and Trichogramma nerudai Pintureau and Gerding in Portugal. Apart from that, Trichogramma oleae Voegele´ and Pointel was collected in Tunisia. This species is probably not indigenous, but has established after several releases of a French strain were made in recent years. For selected strains, the sequence of the internal transcribed spacer 2 (ITS-2) region of rDNA was determined and deposited in the GenBank database. Differences in important biological attributes were found among collected strains of T. bourarachae, suggesting the existence of biotypes. The results contribute to the limited knowledge on distribution and biodiversity of the genus Trichogramma in the Mediterranean region. They can be helpful for the preservation and use of indigenous Trichogramma species in biological control of lepidopterous pests in olive and other local crops

    Entwicklung nachhaltiger Pflanzenschutzstrategien zur Bek_mpfung von Schadschmetterlingen im olivenanbau

    Get PDF
    Current olive growing practices range from the traditional Mediterranean olive grove to intensively managed olive plantations. Insecticides against major olive pests, like the olive moth (Prays oleae, Lep.: Yponomeutidae) and the jasmine moth, (Palpita unionalis, Lep.: Pyralidae) are still applied frequently. The European Union-funded international research project TRIPHELIO is aimed at the development of economically feasible and sustainable insecticide-free control methods for key Lepidopterous pests of olive. Main research activities focus on (1) the use of pheromones for mating disruption and improved monitoring of target pests, (2) habitat management strategies to enhance the activity of natural enemies in the olive grove, and (3) the use of inundative releases of mass-reared egg parasitoids of the genus Trichogramma. Moreover, tools for successful integration of the methods developed into an integrated pest management (IPM) strategy for olive pests were explored by optimising techniques for surveillance as well as considering potential side-effects of common pesticides on beneficial organisms. An intense exchange of scientific information and technology between European and North African countries was undertaken to create solutions for a wide range of olive growing regions. Key results and recommendations for further essential steps towards practical implementation are presented in this publication.Zusammenfassung Traditionelle, extensiv bearbeitete Olivenhaine, aber auch moderne Intensiv-Plantagen mit k_nstlicher Bew_sserung und hohem Einsatz von D_ngern bzw. chemischen Pflanzenschutzmitteln kennzeichnen die derzeitigen verschiedenen Anbauformen der Olive im Mittelmeerraum. Schadlepidopteren wie die Olivenmotte (Prays oleae, Lep.: Yponomeutidae) und die Jasminmotte (Palpita unionalis, Lep.: Pyralidae) werden durch regelm_ssigen Insektizideinsatz bek_mpft. Das von der EU gef_rderte internationale Forschungsprojekt TRIPHELIO zielte auf die Entwicklung insektizidfreier Alternativmethoden durch (1) die Optimierung der pheromongest _tzten _berwachung und Verwirrtechnik, (2) der Anwendung von Habitatmanagement-Strategien zur F_rderung nat_rlicher Gegenspieler, und (3) dem Einsatz von Trichogramma-Schlupfwespen. Zus_tzlich wurden Module f_r eine optimale Anwendung biotechnischer und biologischer Methoden bez_glich der Ph_nologie der Schadinsekten und m_glicher Nebenwirkungen von Pestiziden erarbeitet. Die intensive Kooperation zwischen Wissenschaftlern und Praktikern aus mehreren L_ndern Europas und Nordafrikas erlaubte den Entwurf m_glicher L_sungsans_tze f_r verschiedene Anbaubedingungen und klimatische Regionen des Mittelmeerraumes. Die wichtigsten Ergebnisse und Ausblicke f_r eine zuk_nftige praktische Umsetzung werden in dieser Ver_ffentlichung beschrieben

    A major root architecture QTL responding to water limitation in durum wheat

    Get PDF
    The optimal root system architecture (RSA) of a crop is context dependent and critical for efficient resource capture in the soil. Narrow root growth angle promoting deeper root growth is often associated with improved access to water and nutrients in deep soils during terminal drought. RSA, therefore is a drought-adaptive trait that could minimize yield losses in regions with limited rainfall. Here, GWAS for seminal root angle (SRA) identified seven marker-trait associations clustered on chromosome 6A, representing a major quantitative trait locus (qSRA-6A) which also displayed high levels of pairwise LD (r 2 = 0.67). Subsequent haplotype analysis revealed significant differences between major groups. Candidate gene analysis revealed loci related to gravitropism, polar growth and hormonal signaling. No differences were observed for root biomass between lines carrying hap1 and hap2 for qSRA-6A, highlighting the opportunity to perform marker-assisted selection for the qSRA-6A locus and directly select for wide or narrow RSA, without influencing root biomass. Our study revealed that the genetic predisposition for deep rooting was best expressed under water-limitation, yet the root system displayed plasticity producing root growth in response to water availability in upper soil layers. We discuss the potential to deploy root architectural traits in cultivars to enhance yield stability in environments that experience limited rainfall.Samir Alahmad, Khaoula El Hassouni, Filippo M. Bassi, Eric Dinglasan, Chvan Youssef, Georgia Quarry, Alpaslan Aksoy, Elisabetta Mazzucotelli, Angéla Juhász, Jason A. Able, Jack Christopher, Kai P. Voss-Fels and Lee T. Hicke

    Triphelio – an international research project for sustainable control of lepidopterous pests in olive groves.

    Get PDF
    The olive moth (Prays oleae, Lepidoptera: Plutellidae) is known as one of the key pests in olive cultivation. In particular areas, also the jasmine moth (Pal pita zmionalis, Lepidoptera: Pyralidae) can cause serious damage to both leaves and fiuits of the olive tree. Both pests are mainly controlled by insecticide applications. In November 200 I, an international research project was started to promote biological and biotechnical methods for the control of these pests

    Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV

    Full text link
    We report the results of a study of color coherence effects in ppbar collisions based on data collected by the D0 detector during the 1994-1995 run of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8 TeV. Initial-to-final state color interference effects are studied by examining particle distribution patterns in events with a W boson and at least one jet. The data are compared to Monte Carlo simulations with different color coherence implementations and to an analytic modified-leading-logarithm perturbative calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters
    corecore