1,330 research outputs found
A scheduling and diagnostic system for scientific satellite GEOTAIL using expert system
The Intelligent Satellite Control Software (ISACS) for the geoMagnetic tail observation satellite named GEOTAIL (launched in July 1992) has been successfully developed. ISACS has made it possible by applying Artificial Intelligence (AI) technology including an expert system to autonomously generate a tracking schedule, which originally used to be conducted manually. Using ISACS, a satellite operator can generate a maximum four day period of stored command stream autonomously and can easily confirm its safety. The ISACS system has another function -- to diagnose satellite troubles and to suggest necessary remedies. The workload of satellite operators has drastically been reduced since ISACS has been introduced into the operations of GEOTAIL
Preparation and Properties of Δ-Fe3N-Based Magnetic Fluid
In this work, Δ-Fe3N nanoparticles and Δ-Fe3N-based magnetic fluid were synthesized by chemical reaction of iron carbonyl and ammonia gas. The size of Δ-Fe3N nanoparticles was tested by TEM and XRD. Stable Δ-Fe3N-based magnetic fluid was prepared by controlling the proper ratio of carrier liquid and surfactant. The saturation magnetization of stable Δ-Fe3N-based magnetic fluid was calculated according to the volume fraction of the particles in the fluid. The result shows that both the calculated and measured magnetizations increase by increasing the particle concentration. With the increasing concentration of the Δ-Fe3N particles, the measured value of the magnetic fluid magnetization gradually departs from the calculated magnetization, which was caused by agglomeration affects due to large volume fraction and large particle size
Empirically Driven Use Case Metamodel Evolution
Metamodel evolution is rarely driven by empirical evidences of metamodel
drawbacks. In this paper, the evolution of the use case metamodel used
by the publicly available requirements management tool REM is presented. This
evolution has been driven by the analysis of empirical data obtained during the
assessment of several metricsâbased verification heuristics for use cases developed
by some of the authors and previously presented in other international fora.
The empirical analysis has made evident that some common defects found in
use cases developed by software engineering students were caused not only by
their lack of experience but also by the expressive limitations imposed by the underlying
use case metamodel used in REM. Once these limitations were clearly
identified, a number of evolutionary changes were proposed to the REM use case
metamodel in order to increase use case quality, i.e. to avoid those situations in
which the metamodel were the cause of defects in use case specifications.Ministerio de Ciencia y TecnologĂa TIC 2003-02737-C02-0
Avaliação quantitativa da microbiota em solo de cultivo de soja transgĂȘnica em seis locais do Brasil.
A biomassa microbiana Ă© responsĂĄvel por funçÔes chave para a qualidade do solo, e o cultivo de soja transgĂȘnica bem como o uso de herbicidas pode causar alteraçÔes sobre esse importante componente biolĂłgico do solo. O objetivo do presente trabalho foi avaliar quantitativamente o carbono (CBM) e o nitrogĂȘnio (NBM) da biomassa microbiana de solo cultivado com soja transgĂȘnica e aplicação de herbicidas em seis locais do Brasil na safra 2005/2006. O delineamento experimental foi de bloco ao acaso, com seis repetiçÔes, em sistema de plantio direto. Os tratamentos foram: T1: soja transgĂȘnica + glifosato; T2: soja transgĂȘnica + herbicidas convencionais; T3: soja parental convencional + herbicidas convencionais; T4: soja transgĂȘnica + capina manual; T5: soja parental convencional + capina manual, combinados com trĂȘs cultivares em cada local estudado, totalizando 15 tratamentos. Os solos foram coletados no estĂĄgio R2 na profundidade 0-10 cm para a avaliação do CBM e do NBM. A anĂĄlise de contrastes mostrou que o CBM nĂŁo foi afetado pela transgenia, com exceção de Uberaba (MG). NĂŁo houve diferenças entre o manejo convencional da soja (soja e herbicidas convencionais) e o transgĂȘnico (soja transgĂȘnica com glifosato) em relação ao CBM, tambĂ©m com exceção de Uberaba. O NBM, em geral, nĂŁo foi afetado pela transgenia. Em dois locais (Ponta Grossa/PR e Passo Fundo/RS), o manejo convencional apresentou maior NBM, enquanto o manejo transgĂȘnico com glifosato foi superior em Luiz Eduardo MagalhĂŁes (BA). Conclui-se que o cultivo transgĂȘnico da soja nĂŁo afetou a biomassa microbiana do solo.Fertbio
Fixação biolĂłgica do nitrogĂȘnio em soja transgĂȘnica e aplicação de glifosato durante trĂȘs safras consecutivas no Brasil.
RelaçÔes entre atributos microbiolĂłgicos e bioquĂmicos do solo com a produtividade de soja em sistema de plantio direto.
O sistema de plantio direto (SPD) permite maior conservação do solo e da ĂĄgua, melhoria da fertilidade do solo e da atividade biolĂłgica, garantindo maior sustentabilidade ao sistema de produção. O objetivo desse trabalho foi identificar atributos microbiolĂłgicos e bioquĂmicos do solo que auxiliem a explicar nĂveis de produtividade de soja cultivada sob SPD, por meio de mĂ©todos multivariados. As amostragens foram realizadas em janeiro e setembro de 2011 em Ponta Grossa, PR, em ĂĄreas de cultivo comercial de grĂŁos. Foram coletadas 4 amostras compostas de solo, na profundidade 0-10 cm, em 6 ĂĄreas agrĂcolas com histĂłrico de diferentes nĂveis de produtividades de grĂŁos. Foram avaliadas a respiração basal (RB), biomassa microbiana de carbono (BMC) e nitrogĂȘnio (BMN), atividade das enzimas desidrogenase, celulase, glutaminase e fosfatase ĂĄcida. Calculou-se o quociente metabĂłlico (qCO2) pela razĂŁo entre RB e BMC. Os dados foram submetidos Ă anĂĄlise de componentes principais (ACP) e anĂĄlise canĂŽnica discriminante (ACD). Na ACP, os bioindicadores avaliados foram relacionados principalmente Ă s ĂĄreas de alta produtividade de grĂŁos. A ACD evidenciou a capacidade da BMC e da atividade enzimĂĄtica em discriminar as ĂĄreas de acordo com os nĂveis de produtividade. Conclui-se que os bioindicadores BMC e atividade das enzimas celulase, glutaminase e fosfatase ĂĄcida, podem ser usados para auxiliar a explicar nĂveis de produtividade de soja em ĂĄreas de produção agrĂcola comercial.Fertbio
Structure of particle assembly in water-based magnetite magnetic fluid under zero applied field
Solution Structure of a TBPâTAFII230 Complex Protein Mimicry of the Minor Groove Surface of the TATA Box Unwound by TBP
AbstractGeneral transcription factor TFIID consists of TATA boxâbinding protein (TBP) and TBP-associated factors (TAFIIs), which together play a central role in both positive and negative regulation of transcription. The N-terminal region of the 230 kDa Drosophila TAFII (dTAFII230) binds directly to TBP and inhibits TBP binding to the TATA box. We report here the solution structure of the complex formed by dTAFII230 N-terminal region (residues 11â77) and TBP. dTAFII23011â77 comprises three α helices and a ÎČ hairpin, forming a core that occupies the concave DNA-binding surface of TBP. The TBP-binding surface of dTAFII230 markedly resembles the minor groove surface of the partially unwound TATA box in the TBPâTATA complex. This protein mimicry of the TATA element surface provides the structural basis of the mechanism by which dTAFII230 negatively controls the TATA boxâbinding activity within the TFIID complex
INDEX: A Piggy-Back Satellite for Advanced Technology Demonstration
This paper describes outline of the piggy-back satellite INDEX for demonstration of advanced satellite technologies as well as for a small scale science mission. INDEX satellite will be launched in 2002 by Japanese H2-A. The satellite is mainly controlled by the high-speed, fault-tolerant on-board RIes processor (three-voting system of SH-3). The attitude control is a compact system of three-axis stabilization. Although the size of INDEX is small (50Kg class), several newly-developed technologies are applied to the satellite system, including silicon-on-insulator devices, variable emittance radiator, solar-concentrated paddles, lithium-ion battery, and GPS receiver with all-sky antenna-coverage. These technology developments will be applied to Japanese scientific space exploration in future
Steady State of microemulsions in shear flow
Steady-state properties of microemulsions in shear flow are studied in the
context of a Ginzburg-Landau free-energy approach. Explicit expressions are
given for the structure factor and the time correlation function at the one
loop level of approximation. Our results predict a four-peak pattern for the
structure factor, implying the simultaneous presence of interfaces aligned with
two different orientations.
Due to the peculiar interface structure a non-monotonous relaxation of the
time correlator is also found.Comment: 5 pages, 3 figure
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