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Zeitschriftenartikel zum Thema "CFSRR"
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Lukens, Katherine E., und Ernesto Hugo Berbery. „Winter Storm Tracks and Related Weather in the NCEP Climate Forecast System Weeks 3–4 Reforecasts for North America“. Weather and Forecasting 34, Nr. 3 (01.06.2019): 751–72. http://dx.doi.org/10.1175/waf-d-18-0113.1.
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Abstract This article examines to what extent the NCEP Climate Forecast System (CFS) weeks 3–4 reforecasts reproduce the CFS Reanalysis (CFSR) storm-track properties, and if so, whether the storm-track behavior can contribute to the prediction of related winter weather in North America. The storm tracks are described by objectively tracking isentropic potential vorticity (PV) anomalies for two periods (base, 1983–2002; validation, 2003–10) to assess their value in a more realistic forecast mode. Statistically significant positive PV biases are found in the storm-track reforecasts. Removal of systematic errors is found to improve general storm-track features. CFSR and Reforecast (CFSRR) reproduces well the observed intensity and spatial distributions of storm-track-related near-surface winds, with small yet significant biases found in the storm-track regions. Removal of the mean wind bias further reduces the error on average by 12%. The spatial distributions of the reforecast precipitation correspond well with the reanalysis, although significant positive biases are found across the contiguous United States. Removal of the precipitation bias reduces the error on average by 25%. The bias-corrected fields better depict the observed variability and exhibit additional improvements in the representation of winter weather associated with strong-storm tracks (the storms with more intense PV). Additionally, the reforecasts reproduce the characteristic intensity and frequency of hazardous strong-storm winds. The findings suggest a potential use of storm-track statistics in the advancement of subseasonal-to-seasonal weather prediction in North America.
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Guan, Yuanhong, Jieshun Zhu, Bohua Huang, Zeng-Zhen Hu und James L. Kinter III. „South Pacific Ocean Dipole: A Predictable Mode on Multiseasonal Time Scales“. Journal of Climate 27, Nr. 4 (10.02.2014): 1648–58. http://dx.doi.org/10.1175/jcli-d-13-00293.1.
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Abstract Evaluating the climate hindcasts for 1982–2009 from the NCEP CFS Reanalysis and Reforecast (CFSRR) project using the Climate Forecast System, version 2 (CFSv2), this study identifies substantial areas of high prediction skill of the sea surface temperature (SST) in the South Pacific. The skill is the highest in the extratropical oceans on seasonal-to-interannual time scales, and it is only slightly lower than that for the El Niño–Southern Oscillation (ENSO). Two regions with the highest prediction skills in the South Pacific in both the CFSv2 and persistence hindcasts coincide with the active centers of opposite signs in the South Pacific Ocean dipole (SPOD) mode, a seesaw between the subtropical and extratropical SST in the South Pacific with a strong phase locking to austral summer. Interestingly, the CFSv2 prediction exhibits skillful predictions made three seasons ahead, more superior to the persistence forecast, suggesting significant dynamical predictability of the SPOD. An austral “spring predictability barrier” is noted in both the dynamical and persistence hindcasts. An analysis of the observational and model data suggests that the SPOD mode is significantly associated with ENSO, as an oceanic response to the atmospheric planetary wave trains forced by the anomalous atmospheric heating in the western Pacific. Although previous studies have demonstrated that the pattern of subtropical SST dipole is ubiquitous in the Southern Ocean, the SPOD has been least known and studied, compared with its counterparts in the south Indian and Atlantic Oceans. Since the SPOD is the most predictable oceanic mode in the whole Southern Hemisphere, its climate effects for local and remote regions should be further studied.
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Guan, Hong, und Yuejian Zhu. „Development of Verification Methodology for Extreme Weather Forecasts“. Weather and Forecasting 32, Nr. 2 (22.02.2017): 479–91. http://dx.doi.org/10.1175/waf-d-16-0123.1.
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Abstract In 2006, the statistical postprocessing of the National Centers for Environmental Prediction (NCEP) Global Ensemble Forecast System (GEFS) and North American Ensemble Forecast System (NAEFS) was implemented to enhance probabilistic guidance. Anomaly forecasting (ANF) is one of the NAEFS products, generated from bias-corrected ensemble forecasts and reanalysis climatology. The extreme forecast index (EFI), based on a raw ensemble forecast and model-based climatology, is another way to build an extreme weather forecast. In this work, the ANF and EFI algorithms are applied to extreme cold temperature and extreme precipitation forecasts during the winter of 2013/14. A highly correlated relationship between the ANF and EFI allows the determination of two sets of thresholds to identify extreme cold and extreme precipitation events for the two algorithms. An EFI of −0.78 (0.687) is approximately equivalent to a −2σ (0.95) ANF for the extreme cold event (extreme precipitation) forecast. The performances of the two algorithms in forecasting extreme cold events are verified against analysis for different model versions, reference climatology, and forecasts. The verification results during the winter of 2013/14 indicate that ANF forecasts more extreme cold events with a slightly higher skill than EFI. The bias-corrected forecast performs much better than the raw forecast. The current upgrade of the GEFS has a beneficial effect on the extreme cold weather forecast. Using the NCEP Climate Forecast System Reanalysis and Reforecast (CFSRR) as a climate reference gives a slightly better score than the 40-yr reanalysis. The verification methodology is also extended to an extreme precipitation case, showing a broad potential use in the future.
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Slater, Andrew G. „Surface Solar Radiation in North America: A Comparison of Observations, Reanalyses, Satellite, and Derived Products*“. Journal of Hydrometeorology 17, Nr. 1 (29.12.2015): 401–20. http://dx.doi.org/10.1175/jhm-d-15-0087.1.
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Abstract Observations of daily surface solar or shortwave radiation data from over 4000 stations have been gathered, covering much of the continental United States as well as portions of Alberta and British Columbia, Canada. The quantity of data increases almost linearly from 1998, when only several hundred stations had data. A quality-control procedure utilizing threshold values along with computing the clear-sky radiation envelope for individual stations was implemented to both screen bad data and rescue informative data. Over two-thirds of the observations are seen as acceptable. There are 15 different surface solar radiation products assessed relative to observations, including reanalyses [Twentieth-Century Reanalysis (20CR), CFS Reanalysis and Reforecast (CFSRR), ERA-Interim, Japanese 55-year Reanalysis Project (JRA-55), MERRA, NARR, and NCEP–NCAR Reanalysis 1 (NCEP-1)], derived products [observations from the CRU and NCEP-1 (CRU–NCEP); Daily Surface Weather and Climatological Summaries (Daymet); Global Land Data Assimilation System, version 1 (GLDAS-1); Global Soil Wetness Project Phase 3 (GSWP3); Multiscale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP); and phase 2 of the North American Land Data Assimilation System (NLDAS-2)], and two satellite products (CERES and GOES). All except the CERES product have daily or finer temporal resolution. The RMSE of spatial biases is greater than 18 W m−2 for 13 of the 15 products over the summer season (June–August). None of the daily resolution products fulfill all three desirable criteria of low (<5%) annual or seasonal bias, high correlation with observed cloudiness, and correct distribution of clear-sky radiation. Some products display vestiges of underlying algorithm issues [e.g., from the Mountain Microclimate Simulation Model, version 4.3 (MTCLIM 4.3)] or bias-correction methods. A new bias-correction method is introduced that preserves clear-sky radiation values and better replicates cloudiness statistics. The current quantity of data over the continental United States suggests that a solar radiation product based on, or enhanced with, observations is feasible.
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Burger, J. H., und W. D. Hamman. „The relationship between the accounting sustainable growth rate and the cash flow sustainable growth rate“. South African Journal of Business Management 30, Nr. 4 (31.12.1999): 101–9. http://dx.doi.org/10.4102/sajbm.v30i4.761.
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The accounting sustainable growth rate is used by financial managers and bankers to determine possible financing needs and investment opportunities for companies. However, the authors contend that as this rate is based upon accrual figures that do not reflect the cash position of a company, it could lead to situations in which the company could grow itself into cash problems. In this regard they suggest a cash flow sustainable growth rate (CFSGR), which is defined as the rate at which the company can grow whilst still maintaining a target cash balance in the balance sheet. The relationship between the accounting SGR and CFSGR is then investigated. The authors found that while the accounting SGR is not affected by the non-cash components of working capital, nor by any changes in the non-cash components of working capital, the CFSGR is. Both rates are influenced by the profitability of the company. The accounting SGR is influenced by the growth in sales, while CFSGR is not. The authors do not contend that the CFSGR should replace the accounting SGR, but that it is in the company's best interest to take cognizance of the CFSGR and its implications for the company's growth and cash position.
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Gu, Pengfei, Yongxiang Wu, Guodong Liu, Chengcheng Xia, Gaoxu Wang, Jing Xia, Ke Chen, Xiaohua Huang und Daiyuan Li. „Application of meteorological element combination-driven SWAT model based on meteorological datasets in alpine basin“. Water Supply 22, Nr. 3 (22.11.2021): 3307–24. http://dx.doi.org/10.2166/ws.2021.397.
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Abstract Thus far, reanalysis-based meteorological products have drawn little attention to the influence of meteorological elements of products on hydrological modeling. This study aims to evaluate the hydrological application potential of the precipitation, temperature, and solar radiation of the China Meteorological Assimilation Driving Datasets for the Soil and Water Assessment Tool (SWAT) model (CMADS) and Climate Forecast System Reanalysis (CFSR) in an alpine basin. The precipitation, temperature, and solar radiation of the gauge-observed meteorological dataset (GD), CFSR, and CMADS were cross-combined, and 20 scenarios were constructed to drive the SWAT model. From the comprehensive comparisons of all scenarios, we drew the following conclusions: (1) among the three meteorological elements, precipitation has the greatest impact on the simulation results, and using GD precipitation from sparse stations yielded better performance than CMADS and CFSR; (2) although the SWAT modeling driven by CMADS and CFSR performed poorly, with CMADS underestimation and CFSR overestimation, the temperature and solar radiation of CMADS and CFSR can be an alternative data source for streamflow simulation; (3) models using GD precipitation, CFSR temperature, and CFSR solar radiation as input yielded the best performance in streamflow simulation, suggesting that these data sources can be applied to this data-scarce alpine region.
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Afonso, João Maria de Sousa, Natalia Fedorova, Vladimir Levit und Lianet Hernández Pardo. „Estudo de baixa visibilidade no aeroporto de Porto Alegre: Simulação numérica com o modelo PAFOG“. Revista Ibero-Americana de Ciências Ambientais 10, Nr. 6 (05.11.2019): 114–30. http://dx.doi.org/10.6008/cbpc2179-6858.2019.006.0011.
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A elaboração deste trabalho foi motivada pela carência de um método eficaz de previsão de visibilidade no aeroporto Salgado Filho (Porto Alegre, RS). Os objetivos principais são: 1) simular, usando o modelo PAFOG, os eventos de visibilidade baixa causados por nevoeiros de radiação no aeroporto de Porto Alegre nos anos 2008 e 2009 e 2) avaliar os resultados das simulações inicializadas com diferentes fontes de dados. Perfis verticais de radiossondagem e de dados de previsão (CFSR-2) do modelo CFSR foram utilizados para as inicializações do modelo. Nas inicializações foram utilizados dados de superfície com as duas fontes. Variáveis na camada limite (CL) foram calculadas com dados do modelo CFSR (análise CFSR-1 e CFSR-2). Os dados de altitude foram obtidos de radiossonda e CFSR-2 (resolução 0,5°). Foram selecionados todos (13) casos de nevoeiros de radiação nas horas de observação de radiossondagem. Foram analisadas as condições físicas da baixa troposfera: 1) analise sinótica e de meso escala com produtos de reanálise do NCEP e CFSR-1 com 2,5° e satélite GOES-12; 2) dinâmica acima da CL com CFSR-1 e CFSR-2 com 0,5°, e 3) perfil vertical de umidade relativa (UR) com radiossondagem e produtos do CFSR-2 com 0,5°. Foram feitas 25 inicializações com perfis de radiossondagem e 48 com perfis do CFRS-2 com antecedência de até 22h. Nos horários das inicializações as análises sinótica, dinâmica e de perfil de UR mostraram condições favoráveis ao uso do PAFOG. Em algumas situações foram detectados erros da extrapolação do ponto de orvalho com os perfis do CFSR-2. A influência das extremidades de Sistemas Frontais (SF) em algumas inicializações gerou vento geostrófico superior ao limite suportado pelo modelo PAFOG. Com perfis do CFSR-2 o PAFOG acertou visibilidade de nevoeiro em 36 simulações e não acertou em 12 (em 10 devido aos erros na extrapolação de UR e em 2 devido a influência de SF). Com o CFSR-2 as melhores simulações foram inicializadas às 1200UTC do dia anterior ao evento e às 0000UTC do dia do evento. Com perfis de radiossonda o PAFOG acertou visibilidade de nevoeiro em 22 simulações e não em 3. Os resultados mostraram um grande potencial do uso do PAFOG para a previsão de nevoeiros no aeroporto Salgado Filho, porém, também mostraram necessidade para adaptar o modelo às condições climáticas da região.
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Ostrowski, Krzysztof. „Does the Carbon Fibre Coating Reinforcement Have an Influence on the Bearing Capacity of High-Performance Self-Compacting Fibre-Reinforced Concrete?“ Materials 12, Nr. 24 (05.12.2019): 4054. http://dx.doi.org/10.3390/ma12244054.
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This study investigated the impact of the location of a carbon fibre coated reinforcement ring (CFCRr) inside the structure of high-performance self-compacting fibre-reinforced concrete (HPSCFRC). Nowadays, cement matrix is considered as an alternative binder when reinforcing concrete structures with composite materials. Due to the plastic behavior of composite structures at relatively low temperatures when carbon fibres are reinforced with epoxy resin, the author attempted to locate carbon fibres inside a concrete structure. Thanks to this, the reinforcement will be less vulnerable to high temperatures (during a fire) and more compatible with concrete. The fibres act as a perimeter reinforcement that is compatible with the concrete mixture. The position of the CFCRr in the structure of concrete has an influence on the load capacity, stiffness and stress-strain behavior of concrete elements. The research was conducted on circular shape short concrete columns and tested under axial compression. The results demonstrated that by including CFCRr inside a concrete specimen, the maximum compressive strength decreases with an increase in the number of composite rings and a greater distance from the vertical axis of symmetry to the edge of the element. It has been proven in these studies that carbon fibres do not have good adhesive properties between CFCRr and a concrete mixture. As a result of this phenomenon, a shear surface is created, which leads to crack propagation along the CFCRr. Therefore, the presented idea of an internal CFCRr should not be used when designing new concrete structures.
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Afonso, João Maria de Sousa, Vladimir Levit und Natalia Fedorova. „Estudo de baixa visibilidade no aeroporto de Porto Alegre: processos sinóticos e termodinâmicos“. Revista Ibero-Americana de Ciências Ambientais 10, Nr. 6 (05.11.2019): 131–45. http://dx.doi.org/10.6008/cbpc2179-6858.2019.006.0012.
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O nevoeiro é um fenômeno associado a redução da visibilidade, causando prejuízos em diversos sectores socioeconômicos no estado do Rio Grande do Sul, influenciando principalmente no encerramento das atividades aeroportuárias. Os objetivos principais são: 1) classificar os tipos de nevoeiros em Porto Alegre em um período de 2 anos (2008-2009) a partir da análise dos processos sinóticos e termodinâmicos e 2) avaliar o comportamento de produtos de reanálise do NCEP, reanalise (CFSR-1) e previsão (CFSR-2) do CFSR nas situações de formação de nevoeiro de radiação. Variáveis meteorológicas da estação de superfície do aeroporto foram utilizadas para: 1) o estudo de frequência de nevoeiros e 2) a análise das condições de formação dos nevoeiros. Os sistemas sinóticos atuantes durante os eventos de nevoeiros foram analisados utilizando diversos produtos de reanálise do NCEP e do CFSR e imagens de satélite GOES-12. As condições termodinâmicas foram analisadas usando dados de radiossondagem e perfis plotados com o produto CFSR-1 e CFSR-2. Foram encontrados 82 casos de nevoeiros com duração entre 10 minutos e 11 horas, ocorrendo principalmente no outono e no inverno. Um único caso ocorreu com chuva. A análise sinotica foi elaborada para os 23 casos que ocorreram no horário de observação de radiossondagem. O estudo dos processos sinóticos mostrou que 13 eventos foram nevoeiros de radiação e 10 frontais. Os perfis do CFSR-1 mostraram camada úmida entre 1000-950hPa, com umidade de 86-89%. Os perfis do CFSR-2 mostraram camada úmida entre a altura 2m até o nível de 950hPa com umidade de 80-96.9%. No geral, os perfis de toda a troposfera acima desses níveis foram típicos para os casos de nevoeiros radiação, com baixa umidade e inversões de subsidência. Concluímos que 1) a situação sinóptica foi apresentada semelhante pelo NCEP e o CFSR, 2) os perfis do CFSR mostram a estrutura da troposfera típica para os eventos de nevoeiro de radiação, excluindo a camada superficial.
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Bapat, P. M., und L. L. Tavlarides. „Mass transfer in a liquid-liquid CFSTR“. AIChE Journal 31, Nr. 4 (April 1985): 659–66. http://dx.doi.org/10.1002/aic.690310416.
Der volle Inhalt der QuelleDissertationen zum Thema "CFSRR"
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Chen, Liang. „Design of decoupling control and time-delay compensation for a CFSTR“. Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29469.
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This thesis is concerned with the design of a decoupling compensator and a time-delay compensator for a nonisothermal continuous flow stirred tank reactor (CFSTR). An expression for the analysis of interaction of the two-variable CFSTR was theoretically derived by using the relative gain method (RGM). For the purpose of improving the stability of the decoupling control system, undercompensation for a decoupled CFSTR system was suggested and the robustness test of such undercompensation decoupler to the modelling error was studied. On the other hand, the proposed time-delay compensation method, unlike conventional Smith's scheme, can rely on the basic property of gain-invariant time-delay. The stability of this time-delay compensation method is not affected by the CFSTR control system time-variant time-delay, while its compensation structure has the same features as the Smith compensator.
The design of a decoupler and that of a time-delay compensator are independent of each other. All compensation structures are physically realizable.
The theoretical results are supported by simulation. Simulation results for a CFSTR demonstrate that the undercompensation decoupling control can tolerate a relatively wide modelling error and reduce the sensitivity of the CFSTR process to parameter variations and unwanted disturbances. Also, simulation results show that the proposed time-delay compensator can provide an improvement over the conventional Smith compensator.Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
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Mieres, Luciana da Silva. „Reanálise CFSR-NCEP aplicada ao modelo SiB2 na simulação de fluxos de CO2 sobre o cultivo de soja em Cruz Alta“. reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/62124.
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Este trabalho buscou avaliar o comportamento dos fluxos de CO2, simulados pelo modelo de superfície SiB2, a partir da adoção dos dados de reanálise CFSR-NCEP como condições de contorno atmosféricas. Para a validação dos resultados obtidos utilizou-se uma análise estatística, através de um coeficiente de ajuste, o qual foi embasado nos parâmetros simulados em comparação aos dados observados, sendo estes obtidos pela torre micrometeorológica sitiada na área de cultivo. O estudo foi aplicado ao sítio experimental de soja localizado em Cruz Alta (-28,6036; -53,6736) no Rio Grande do sul e o período adotado compreendeu os anos de 2008 e 2009. Inicialmente foi necessário realizar a calibração de alguns parâmetros presentes nas sub-rotinas (módulos) do modelo. Para tanto, foi adotada uma metodologia em que os parâmetros foram calibrados conforme os módulos sequenciais, respeitando a seguinte ordem: aerodinâmico, transferência radiativa, difusão hidráulica do solo e fotossíntese e condutância estomática. A calibração do módulo aerodinâmico foi aplicada aos parâmetros referentes à altura do dossel, fração de cobertura vegetal e distribuição do ângulo foliar. No módulo de transferência radiativa, foi calibrado o parâmetro de reflectância da folha viva no visível. A calibração dos parâmetros referentes ao módulo de difusão hidráulica do solo foi realizada na porosidade do solo, profundidade individual das camadas e expoente de umidade. No módulo de fotossíntese e condutância estomática os parâmetros testados foram índice de área foliar, condutância estomática mínima e temperatura crítica para a respiração foliar. A calibração destes parâmetros permitiu que se obtivesse uma substancial melhoria na simulação dos fluxos de CO2 pelo modelo, obtendo-se um ganho expressivo na qualidade da simulação. Esta etapa constitui fundamental importância, uma vez que permitiu que a adoção dos dados de reanálise fosse efetuada no modelo adequado à área de estudo. No que tange a etapa final desta pesquisa, destaca-se que os dados do CFSR foram utilizados como condição de contorno atmosférica. Estas condições são necessárias à inicialização do modelo e originalmente utilizam-se as variáveis meteorológicas obtidas a partir da estação do INMET. Foram adotadas as variáveis referentes à temperatura do ar, pressão atmosférica ao nível do mar, precipitação, radiação de onda curta incidente e velocidade do vento, utilizadas para descrever o estado físico da atmosfera nas novas simulações dos fluxos de CO2, as quais foram comparadas aos dados observados da torre. A partir dos resultados obtidos, presumiu-se que a utilização dos dados de reanálise CFSR-NCEP pode ser considerada aceitável na aplicação de estudos dos fluxos de CO2 a partir do modelo SiB2, ressaltando-se que a calibração do referido modelo à área de estudo é de grande importância para sua adequação e obtenção de resultados mais satisfatórios.The present work aimed to evaluate the behavior of CO2 fluxes, run by the Simple Biosphere Model (SiB2), by adopting CFSR-NCEP data reanalyzed as an atmospheric boundary condition. A statistical analysis was used in order to validate the results obtained using a coefficient for the adjusted model based on the simulation parameters when compared to the data observed in field, which was obtained by the micrometeorological tower located on the cultivation areas. The study was applied in a soybean experimental site located in Cruz Alta (-28,6036; -53,6736), in the state of Rio Grande do Sul, Southern Brazil between 2008 and 2009. Some of the parameters presented in the subroutines of the model had to be adjusted first. For such, a methodology in which the parameters were calibrated in sequential modules was applied according to the following order: aerodynamics, radiative transfer, hydraulic diffusion of the soil and photosynthesis and stomatal conductance. In the aerodynamics module, the calibration was made using the parameters for the canopy height, vegetation coverage and leaf-angle distribution. For the radiative transfer, the calibration used the parameters for the live leaf transmittance visible reflectance. The calibration for the hydraulic diffusion of the soil was accomplished in the soil porosity, depth of individual layers and humidity exponent. For the photosynthesis and stomatal conductance, the parameters tested were the leaf area index, minimum stomatal conductance and leaf respiration critical temperature. It could thus be possible to obtain a considerable improvement for the simulation of the CO2 fluxes in this model for a high-quality simulation. That stage was significantly important since it enabled the reanalysis data to be set in the best model for the studied area. Regarding the final stage of this study, data from the CFSR were used as the atmospheric boundary condition instead of originally applied meteorological variables from the INMET station. Variables concerning air temperature, air pressure at sea level, precipitation, incident short-wave radiation and wind speed were used in order to describe the physical condition of the atmosphere in new simulations with CO2 fluxes, and then compared to the data observed in the micrometeorological tower. From the results, using the CFSR-NCEP reanalysis data can be considered acceptable for studies on CO2 fluxes from the SiB2 model. Yet, calibrating this model for the studied area is a key factor for its suitability and for obtaining adequate results.
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Knight, Daniel William. „Reactor behavior and its relation to chemical reaction network structure“. The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1438274630.
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Tang, Yangzhong. „Calculating limits to productivity in reactor-separator systems of arbitrary design“. Columbus, Ohio : Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1132766319.
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Ledford, M. Gail. „How States Developed Plans to Meet a Federal Mandate: Addressing the Challenges of the Child and Family Services Reviews“. Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/30065.
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Much of the child welfare literature addresses risk factors, incidence, and consequences of abuse and neglect, and innovative programs, services, and interventions designed to serve at-risk and maltreated children, youth, and their families. Less attention has been given to how state and local governments oversee the public child welfare system and respond to federal mandates, especially in achieving positive outcomes for this vulnerable population.
In 1997, the Congress enacted the Adoption and Safe Families Act (ASFA). This legislation mandates that all states meet certain performance and accountability standards regarding safety, permanency, and well-being of children served by their child welfare systems. These issues are important for the approximately 500,000 children in foster care at any point in time. There is also significant concern for the millions of children involved in the child welfare system through investigations, court proceedings, and both mandated and voluntary services.
A significant effort resulting from ASFA is the Child and Family Services Reviews (CFSRs). The myriad requirements under ASFA and the CFSRs create a federal mandate for changes in the way state child welfare systems meet the needs of the children, youth, and families they serve and a process for improving federally defined outcomes.
This study examined how states responded to federal requirements of the CFSRs. Specifically, it looked at how states proposed to address shortcomings identified in relation to two individual child and family well-being outcomes and two systemic factors where they had failed to meet conformance criteria in their CFSR. It is important to understand how the federal-state process transpired to ameliorate these conditions without additional federal funding to implement the CFSR requirements.
Results of this study describe six statesâ strategies related to two well-being outcomes, specifically in the areas of education, physical health, and mental health, and two systemic factors, service array and agency responsiveness to the community, as identified in their Program Improvement Plans (PIPs). Four central themes emerge: complexity of the problems, knowledge base and data to guide improvements, resource availability, and collaboration among agencies. These themes help inform states on the potential benefits and challenges in responding to federal mandates.Ph. D.
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Moraes, Flávia Dias de Souza. „Ambiente atmosférico favorável ao desenvolvimento de complexos convectivos de mesoescala no sul do Brasil“. reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/139067.
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Complexos Convectivos de Mesoescala (CCM) são eventos meteorológicos de difícil previsão, que resultam em tempestades severas e desastres. O objetivo deste trabalho é indicar as características em grande escala do ambiente atmosférico favorável para a formação de CCM no Sul do Brasil, entre 1998 e 2007. Fez-se uso da base de dados de CCM de Durkee e Mote (2009), assim como das variáveis de Potencial de Energia Convectiva Disponível (CAPE), ponto de orvalho, temperatura, altura geopotencial, componentes de vento u e v e umidade relativa da reanálise do National Center for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (CFSR), coletadas entre 2,5 e 5,5 horas antes do desenvolvimento dos CCM. Com o método de Análise das Componentes Principais (ACP), geraram-se as composições do ambiente atmosférico médio favorável ao desenvolvimento dos CCM, para comparar o grupo dos que ocorreram no Sul do Brasil ao dos que atuaram em outras regiões da AS. Usando como dado de entrada as variáveis de altura geopotencial e temperatura (em 850 hPa), foram encontradas quatro componentes principais para cada um dos grupos de CCM. Com base nas componentes principais, nas variáveis atmosféricas e nas cartas sinóticas, foram reconstruídos os ambientes atmosféricos médios para identificar o comportamento das características atmosféricas prévias aos CCM para cada conjunto de eventos. Os resultados identificaram 303 CCM, 96 no Sul do Brasil, 168 em outras regiões da AS e 39 oceânicos. O ambiente atmosférico médio dos 168 CCM não apresentou características homogêneas, pois 75% das componentes não possuíam jatos de baixos níveis (JBN) dentro dos critérios adotados, mas a presença de um escoamento meridional. Esse fluxo, ao encontrar com a região de divergência dos jatos de altos níveis (JAN), foi um dos fatores favoráveis para a convecção, já que seus valores de CAPE (≥ 450 J kg-1) eram menores que a média esperada para formação de tempestades e só uma das componentes teve frentes frias associadas. Por outro lado, o grupo dos 96 CCM que atuaram no Sul do Brasil mostrou-se cerca de 50.000 km² maior em extensão que os das outras regiões da AS e dos EUA e com duração de pelo menos 3 h a mais. Além disso, as características atmosféricas do grupo de CCM do Sul do Brasil mostraram padrões homogêneos, podendo indicar a formação de CCM nessa região quando: o campo de ventos médios em 850 e 200 hPa, se encontrarem em posição ortogonal, indicando acoplamento entre os jatos de baixos e altos níveis; os valores de CAPE forem ≥ 600 J kg-1 e o cisalhamento vertical estiver entre 7 e 12 m s-1; houver atuação das frentes frias no sul da AS; a umidade relativa disponível estiver concentrada próxima à região Sul do Brasil, com valores maiores que 80%; a altura geopotencial (850 hPa) apresentar um cavado na região gênese dos CCM e a temperatura (850 hPa) estiver mais elevada próxima e ao norte da região de formação.Mesoscale Convective Complexes (MCCs) are meteorological events difficult to forecast, which result in severe storms and other natural hazards. This study’s objective is to indicate the large-scale atmospheric environment favorable to develop MCCs in Southern Brazil during the 1998–2007 period. The MCCs database used was from Durkee and Mote (2009) and the variables selected include CAPE (Convective Available Potential Energy), dewpoint temperature, temperature, geopotential height, and relative humidity from National Center for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (CFSR), collected from 2,5 to 5,5 hours before the MCCs’ development. Principal component analysis (PCA) method was used to construct the average atmospheric environments of MCCs group that occurred in Southern Brazil to compare with MCCs that occurred in other regions of South America. Temperature and geopotential height were the variables used for the PCA, resulting in four principal components to each MCCs group. Based on these principal components, meteorological variables and synoptic charts, average atmospheric environments were built to understand the atmospheric parameters that indicate the development of MCCs in each group. Results show 303 MMCs, 96 were located in Southern Brazil, 168 in South America and 39 in the South Atlantic Ocean. The average atmospheric environment from the group of 168 MCCs did not indicate homogeneous characteristics, as 75% of its principal components cannot be characterized as having a low-level jet (LLJ) in the wind field, instead only a meridional flux of humid and warm air at 850 hPa. This air coupled with the upperlevel jet (ULJ) was found to be responsible for convection developing MCCs, as CAPE (≥ 450 J kg-1) was below the average to produce storms and only one component was associated with a cold front. On the other hand, the MCCs’ group of Southern Brazil is on the order of 50.000 km² larger and 3 hours longer than MCCs from other regions of South America and from the United States. Furthermore, the atmospheric characteristics of the Southern Brazil MCCs’ group revealed homogenous patterns, which suggest that the development of MCCs in this region starts when: the mean wind field indicate a coupled LLJ (jet streak between 10 and 12 m s-1) and ULJ (jet streak ≥ 32 m s-1), CAPE value is ≥ 600 J kg-1 and the vertical wind shear is from 7 to 12 m s-1, cold fronts are active in Southern South America, the relative humidity is concentrated in Southern Brazil and above 80%, the geopotential height (850 hPa) indicate a trough in the genesis region of MCCs and the temperature (850 hPa) is higher near and northern the genesis region.
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Koutsouris, Alexander. „Building a coherent hydro-climatic modelling framework for the data limited Kilombero Valley of Tanzania“. Doctoral thesis, Stockholms universitet, Institutionen för naturgeografi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-142201.
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This thesis explores key aspects for synthesizing data across spatiotemporal scales relevant for water resources management in an Eastern Africa context. Specifically, the potential of large scale global precipitation datasets (GPDs) in data limited regions to overcome spatial and temporal data gaps is considered. The thesis also explores the potential to utilize limited and non-continuous streamflow and stream water chemistry observations to increase hydrological process understanding. The information gained is then used to build a coherent hydro-climatic framework for streamflow modelling. In this thesis, Kilombero Valley Drainage Basin (KVDB) in Tanzania is used as an example of a data limited region targeted for rapid development, intensification and expansion of agriculture. As such, it is representative for many regions across the Eastern Africa. With regards to the data synthesis, two satellite products, three reanalysis products and three interpolated products were evaluated based on their spatial and temporal precipitation patterns. Streamflow data from KVDB and eight subcatchments were then assessed for quality with regards to missing data. Furthermore, recession analysis was used to estimate catchment-scale characteristic drainage timescale. Results from these streamflow analyses, in conjunction with a hydrological tracer-based analysis, were then used for improved understanding of streamflow generation in the region. Finally, a coherent modelling framework using the HBV rainfall-runoff model was implemented and evaluated based on daily streamflow simulation. Despite the challenges of data limited regions and the often large uncertainty in results, this thesis demonstrates that improved process understanding could be obtained from limited streamflow records and a focused hydrochemical sampling when experimental design natural variability were leveraged to gain a large signal to noise ratio. Combining results across all investigations rendered information useful for the conceptualization and implementation of the hydro-climatic modelling framework relevant in Kilombero Valley. For example, when synthesized into a coherent framework the GPDs could be downscaled and used for daily streamflow simulations at the catchment scale with moderate success. This is promising when considering the need for estimating impacts of potential future land use and climate change as well as agricultural intensification.Denna avhandling utforskar aspekter på att syntetisera data med olika rumslig och temporal upplösning, vilket är centralt för vattenförvaltning i östra Afrika. Särskilt fokus ligger på att undersöka möjligheten till att använda globala nederbördsdataset för att fylla rumsliga och temporala luckor där data saknas. Avhandlingen undersökeräven möjligheten till att använda flödesdata med icke-kompletta tidsserier samt kemidata från vattendrag för att utöka kunskap-en om hydrologiska processer. Informationen används för att bygga upp ett integrerande ram-verk för hydro-klimatologisk modellering som exempelvis kan användas för att utforska ef-fekten av ett utökat och intensifierat jordburk på vattenresurser. I denna avhandling användes Kilomberodalens avrinningsområde (Tanzania) som exempel på ett databegränsat område där det pågår en intensiv utökning av jordbruksverksamhet. Detta område kan ses som representa-tivt för ett stort antal områden inom östra Afrika.Datasyntesen innefattade två nederbördsprodukter baserade på satellitdata, tre baserade på återanalysprodukter samt två baserade på interpolering av observervationsdata från regnmä-tare. Dessa åtta produkter utvärderades baserat på deras nederbördsmönster i rum och tid. Ut-över detta utvärderades vattenföringsdata från Kilomberodalens avrinningsområde samt åtta delavrinningsområden utifrån mängden saknad data i respektive tidsserie. Vidare användes resultaten från hydrologisk recessionsanalysför att uppskatta den karaktäristiska avrinningsti-den för avrinningsområden. Resultaten från recessionsanalysensamthydrologiskt spårämnes-försök användessedan för att utöka kunskapen om avrinningsbildning och vattenföring i om-rådet samt som stöd i valet av hydrologiskt modelleringsverktyg. Avslutningsvis användes HBV-avrinningsmodellen för att simulera daglig vattenföring. Trots utmaningen i att arbeta iett databegränsat område och de osäkerheter i resultat som detta tenderar att leda till visar resultaten att det var möjligt att använda begränsad vattenfö-ringsdata och vattenkemidata för att utöka den hydrologiska processförståelsen av området. Detta möjliggjordes genom ett experimentellt upplägg som utnyttjade till ett stort signal-till-brusförhållande under rådande förhållanden av naturlig variabilitet. Kombinerade resultat från alla genomförda studier kunde utnyttjas vid konceptualiseringen och implementeringen av ramverket för hydroklimatologisk modellering av Kilomberodalens avrinningsområde. Till exempel kunde de globala nederbördsdataseten användas för lokal modellering av flödesdata med viss framgång efter syntes och implementering i det integrerande ramverket för hydro-klimatologisk modellering. Detta är lovande med tanke på behovet av att undersöka vilken påverkan möjliga framtida förändringar i markanvändning, klimat samt jordbruk har på den lokala och regionala miljön.
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.
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SAZID, MOHD. „DESIGN OF COMPACT BAND PASS FILTER FOR UWB APPLICATION WITH MULTIPLE NOTCHES“. Thesis, 2023. http://dspace.dtu.ac.in:8080/jspui/handle/repository/20419.
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Radio frequency (RF) filters are essential components of the present wireless communication
systems as it enables and enhances their functionality. RF filter’s primary objective is to govern
and control electromagnetic signals ensuring that they operate within a particular frequency
spectrum. However, the upper stopband of conventional Ultra-Wideband (UWB) filters was
limited, and they were sensitive to interference from other wireless services. To satisfy the
need of integrated services and overcome the shortcomings of its forerunner, UWB filters have
greatly improved. They are compact and have several notches which are strategically
positioned to improve transmission efficiency. With the help of this development, UWB filters
may be seamlessly integrated into several devices and applications, making more efficient use
of limited space and spectrum allocations. UWB filters play an important role in minimizing
interference and maintaining the smooth functioning of wireless services by targeting and
suppressing undesirable frequencies. In today's technology-driven society, their advanced
designs let numerous systems exist harmoniously, promoting an integrated and efficient
wireless ecosystem. Revolutionary developments, such as high-speed data transfer, Internet of
Things (IoT) applications, and the establishment of smart city infrastructure, have been made
attainable by advancements in UWB filter technology. The capability of these filters to
precisely filter specific radio frequencies provides reliable data transmission, allowing for
smooth communication across a wide range of scenarios and environments.
The design of UWB filters poses a distinctive challenge of strategically incorporating notches
at specific frequencies to effectively mitigate interferences. the design must achieve a wide
bandwidth while maintaining acceptable performance characteristics across the entire
frequency spectrum.
This thesis explains the design and analysis of band pass filters for UWB applications. In the
present endeavour, six filters for UWB applications are fabricated and measured, namely:
MMR-based filter, flexible and transparent filter using silver nanowire, stepped impedance
resonator (SIR) based filter, broadside coupled filter based on microstrip to CPW transition
filter, multiple notches filter based on CSRR, and Hybrid SIR and Modified CSRR based
multiple notches filter. Extensive simulations are used to analyse and then experimentally
validate the aforementioned structural designs. These all suggested filters are suitable for UWB
applications.
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The first chapter offers a concise and comprehensive introduction to UWB (Ultra-Wideband)
technology, providing a foundational understanding of its concepts and applications. It
explores the anticipated spectrums that UWB technology is expected to utilize, highlighting its
potential to exploit a broad range of frequencies for diverse wireless communication purposes.
The second chapter explores the complexity of UWB filter design and provides significant
insights into the underlying concepts and modelling methodologies. The next section of the
chapter explores numerous techniques used to enhance selectivity, passband flatness, stopband
extension, and other frequency characteristics of UWB filters. In addition, the chapter
investigates the implementation of single and multiple-notch functions within the filters,
intending to eliminate any potential in-band interference. The in-depth examination offers a
thorough grasp of the complicated design issues and modern techniques utilized to enhance the
functionality of UWB filters, ensuring the effective suppression of undesirable signals while
maintaining the integrity and quality of the desired UWB signals.
The third chapter describes the construction of planar structures that generate a passband
utilising multimode resonators (MMRs) and interdigital capacitors (IDCs). The upper
transmission zero (TZ) is regulated by the arm dimension of the IDCs, while insertion loss is
reduced by tight coupling among the IDCs' arms. By integrating inverted L-type resonators in
the design, the lower TZ is tuned. The result makes it possible to manage the TZ.
In the fourth chapter, silver nanowires are utilized for creating the circuit on a transparent and
flexible PET substrate. The TZ is controlled by the length of the three pairs of arms that
collectively make up the passband. The TZ of this structure is determined by the arm length of
the IDCs, and it demonstrates an extended stop band of up to 50 GHz.
In the fifth chapter, a dual-notched band UWB-BPF was built using broadside linked
techniques. This structure incorporates complementary split ring resonators (CSRRs) in the
bottom plane to introduce two notches in the passband. These notches are positioned at 5.4
GHz and 8.2 GHz, and they can be independently controlled. By changing the dimension of
the CSRRs, both notches can be positioned to desired frequencies. The incorporation of CSRRs
in the design allows for precise control over the notches, enabling selective suppression of
unwanted frequencies. This dual-notched band UWB filter offers improved interference
rejection capabilities and enhances the overall performance of UWB systems. The design
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methodology here involves optimizing the dimensions and placement of the CSRRs to achieve
the desired notch frequencies.
In the sixth chapter, the planar structure has been designed for the application of triple-notched
bands. In this the structure utilize a broadside coupled technique, employing a basic
architecture of a BPF with microstrip-to- CPW transitions arranged on either side of the
dielectric. This UWB-BPF exhibited favourable frequency characteristics, featuring two TZs
located at the edges of the passband. To eliminate in-band interferences, DGS in the form of
CSRRs and complementary folded split ring resonators (CFSRR) were incorporated, resulting
in the placement of three TZs within the passband. The triple notches were centered at
frequencies of 5.6, 6.42, and 8.03 GHz, attenuating over 19 dB. The measured 3-dB BW of the
suggested filter spanned from 3.25 to 10.73 GHz and stopband attenuation was achieved up to
17 GHz.
The basic geometry of the BPF was built in the seventh chapter employing microstrip lines on
the upper layer linked to an altered CPW on the bottom layer. Because of the presence of two
TZs at the lower and upper edges of the passband, this design with a broadside alignment
produced a highly desirable Ultra-Wideband (UWB) response. This concept was improved
further by incorporating numerous circular resonator CRs and a CFSRR into the basic
architecture. These additional components were added to the ground plane to efficiently
mitigate interference from in-band RF sources. By effectively arranging the CRs and CFSRR,
the filter was able to establish TZs at frequencies of 5.2, 6.5, and 8 GHz, effectively filtering
undesirable signals from WLAN, C band, and X band, respectively.
In the eighth chapter, a compact quad-band notched filter was developed for UWB
applications. This suggested filter was constructed using a single-layered Roger 6010 dielectric
with a height of 0.635 mm and a dielectric constant of 10.8. In this design, Quad notches were
introduced within the passband at frequencies of 3.6 GHz, 5.4 GHz, 7.5 GHz, and 8.7 GHz.
These notches effectively eliminate interference caused by WiMAX, WLAN, C band, and the
super-X band for satellite TV networks (ranging from 7.2 GHz to 8.4 GHz) within the UWB
passband. The quad notches were implemented using SRR and CSRR. The suggested UWB BPF was developed and simulated using IE3D EM simulation software.
Chapter 9 concludes this thesis by, summarizing the findings and contributions presented
throughout the work. It also offers valuable insights and suggestions for potential future
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enhancements and extensions of the research, particularly concerning diverse UWB filter
design applications.
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Yu, Se-Siong, und 尤世雄. „Development of Water Quality Evalute Formulas for CFSBR“. Thesis, 2006. http://ndltd.ncl.edu.tw/handle/g5q9gm.
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碩士國立中央大學
環境工程研究所
94
The continuous-flow sequencing batch reactor (CFSBR) mainly utilizes and monitors the bend of pH and ORP to determine the change of the phase in the development of the real-time control system, the stability of water quality and reduction of cost can already improve and get rid of efficiency. However, some water-quality characteristics, for instance COD, NH4+-N, NO2--N, NO3--N and PO43--P, etc. do not have effectively automatic monitoring technology yet. It makes the anaerobic phase unable to grasp an ammonification and bio-phosphate release, and influence nitrification and bio-phosphate up-take in the follow-up aerobic phase. Thus it leads the bad removal rate and the unstable effluent quality. Though the existing on-line sensors are usually unable to accomplish overall monitoring, these variables are determined with a significant time delay. However, CFSBR is a half-opening system; its water-quality characteristic has certain relation with each other. In this study, the water quality evaluate formulas was developed using the network approach, which can simultaneously utilize on-line information to evaluate water quality. In monitoring and controlling CFSBR, the information of nutrient dynamics is very important. In this reason, this study tries to join the initial value and the state variable into input data. And the results show this method can evaluate NH4+-N, NO2--N, NO3--N and PO43--P concentrations and trends well.
Bücher zum Thema "CFSRR"
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Davis, William Stearns. A Friend Of Cfsar: A Tale Of The Fall Of The Roman Republic. Fredonia Books (NL), 2004.
Den vollen Inhalt der Quelle findenBuchteile zum Thema "CFSRR"
1
Sasmono, R. Tedjo, und Elizabeth Williams. „Generation and Characterization of MacGreen Mice, the Cfs1r-EGFP Transgenic Mice“. In Methods in Molecular Biology, 157–76. Totowa, NJ: Humana Press, 2011. http://dx.doi.org/10.1007/978-1-61779-527-5_11.
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Martinez-Cruz, D. A., M. Gutiérrez und M. T. Alarcón-Herrera. „Spatial and Temporal Analysis of Precipitation and Drought Trends Using the Climate Forecast System Reanalysis (CFSR)“. In Springer Climate, 129–46. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-22464-6_8.
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Silvestrova, Ksenia, Stanislav Myslenkov und Andrey Zatsepin. „Variability of Wind-Driven Coastal Upwelling in the North-Eastern Black Sea in 1979–2016 According to NCEP/CFSR Data“. In Pageoph Topical Volumes, 287–95. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-11958-4_17.
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Sapoundjiev, Hristo, Richard Trottier und Francois Aubé. „Heat recovery from lean industrial methane emissions environmental and economic benefits of CFRR technology“. In Greenhouse Gas Control Technologies 4, 805–10. Elsevier, 1999. http://dx.doi.org/10.1016/b978-008043018-8/50128-4.
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Kessete, Nega, Mamaru A. Moges und Tammo S. Steenhuis. „Evaluating the applicability and scalability of bias corrected CFSR climate data for hydrological modeling in upper Blue Nile basin, Ethiopia“. In Extreme Hydrology and Climate Variability, 11–22. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-12-815998-9.00002-6.
Der volle Inhalt der QuelleKonferenzberichte zum Thema "CFSRR"
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Jeong, Chan Kwon, Alokraj Valsaraj und Harold Velazquez. „Global Wave Persistence Study for Offshore Operation and Planning“. In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-41703.
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This paper describes the guidelines for preliminary workability analysis for offshore operation and planning using global wave persistence study. In offshore engineering, the weather information has to be studied to select the appropriate path for the project during the concept design, the detail design and the operation plan. The workability analysis is part of the weather study for various offshore operations and this study is used as a guide for the operation schedule, the selection of the operation method, the design of the equipment and the supporting structures. The detailed workability analysis is based on response based simulations which are only available after or during detail system design. On the other hand, preliminary workability can be calculated based on hindcast data with statistical methods before the detail design and this study can lead the project on the appropriate path at the beginning stages. The wave persistence analysis with thresholds on time and wave heights is used for the preliminary workability calculation and can also be used for route planning during offshore transportation. The objective of this paper is to provide global wave persistence analysis data to guide offshore operation and planning and makes the transition to workability with the required working wave period easier. For the global wave persistence analysis, the National Center for Environmental Prediction (NCEP) Climate Forecast System Reanalysis Reforecast (CFSRR) system data was used which has 35-year numerical wave hindcast. Data resolution is 0.5°×0.5° grid size with a temporal resolution of 3 hours for the period from 1979 to 2013, and this database covers most offshore locations except the Caspian Sea, and the North and South Pole areas. The persistence analysis was calculated with 0.5m, 1.0m, 1.5m and 2m wave thresholds, and each wave threshold is categorized as 24 hours, 48 hours and 72 hours persistency.
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Pizzigalli, Claudia, Giancarlo Giovanetti, Lisa Pedinelli und Roberto Padilla-Hernandez. „NOAA-CFSR Offshore Wind Validation“. In ASME 2021 3rd International Offshore Wind Technical Conference. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/iowtc2021-3547.
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Abstract The wind field at sea is of considerable interest to identify suitable sites and for designing offshore wind energy production facility. However, the reliability of wind information suffers from the relative scarcity of offshore wind measurements to validate the wind models used in assessments. This paper presents a comparison of the publicly available NOAA-CFSR global re-analysis data set against offshore wind measurement collected in West Africa, Mediterranean Sea, Barents Sea and NW Australia, with the goal to investigate — in widely different meteorological conditions — the overall model reliability, in term of statistical indices of performance: Moreover, an attempt has been made to ascertain the representative averaging duration of model wind and the reliability of engineering formulas used to correlate wind of different averaging durations.
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Qun, Yang, Li Minghai, Hou Jie, He Zhaozhong und Chen Kun. „Application of the Probability-Based Safety Analysis for the Reliability Evaluation of a Special Fuel Salt Release System Design in the Molten Salt Reactor“. In 2017 25th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/icone25-67017.
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In the molten salt reactor (MSR), the fuel salt can be discharged out of the core to avoid a more serious consequence in the accident. In this paper, a special core fuel salt release system (CFSRS) is described. Its equipment reliability and human reliability are evaluated subsequently to identify the key failure factors and provide suggestions for the design, by means of the fault tree analysis and the human reliability analysis (HRA) respectively. Results show that the human error is a dominant factor of CFSRS failure in the accident scenario. A good operator training or a sufficient diagnosis time can greatly improve the CFSRS human reliability. Regardless of the human error, to obtain a balanced design and a low equipment failure probability of less than 2E−5, the redundant design of CFSRS including the pipe heating subsystem is necessary.
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Barrera, Francisco Garcia, und Wilson Castillo Rojas. „Correlation Analysis and Residual Error between Re-Analysis Data of the CFSR Model and Meteorological Stations“. In 2018 7th International Conference On Software Process Improvement (CIMPS). IEEE, 2018. http://dx.doi.org/10.1109/cimps.2018.8626060.
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Rapizo, Henrique, Qingxiang Liu und Alexander V. Babanin. „Performance of the Observation-Based Source Terms in a High-Resolution Wave Hindcast for the North Sea“. In ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/omae2022-78512.
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Abstract A 30-year wave hindcast for the North Sea covering the period of 1990–2020 is described. The simulations are performed by nesting a 5 km SWAN wave model to a global WAVEWATCH III implementation. For the coastal nest several options of the ST6 physics are tested, including choices for the coefficients of whitecapping dissipation, wind drag formulation and scaling of wind speed U10 to friction velocity u*. The results are shown for the two most widely used wind reanalyses: the CFSR and ERA5. The model dataset is validated and calibrated against satellite and several buoy measurements, allowing for the assessment of model performance in the different areas of the North Sea. The ERA5 reanalysis outperforms the CFSR winds in all validation metrics except for a negative bias in wind speed, which is more noticeable for the upper quantiles. Similar results are observed for significant wave height when comparing model results forced by the two reanalysis winds. The ST6 source term performs considerably better than the source terms of van der Westhuysen et al. However, the results are sensitive to the choice of the ST6 tuning parameters, which are in turn also dependent on the forcing winds. Further tests are performed by correcting the wind stress to account for the observed wind speed bias, which is a part of the ST6 implementation. Finally, the long-term statistics of wave height are briefly presented, with emphasis on the wave height extremes.
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Wrenger, Hendrik, Bruno Sainte-Rose und Ivan Soares. „Waves in the Great Pacific Garbage Patch: Cross Validation of Three Measurement Techniques and Two WW3 Models“. In ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18906.
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Abstract The Ocean Cleanup Foundation is developing floating barrier systems to concentrate and extract buoyant plastic from the global accumulation zones. To analyze and improve the efficiency of such cleanup systems, access to accurate Metocean conditions is inevitable. The Ocean Cleanup runs its own implementation of WAVEWATCH III® to have full control over the spatiotemporal resolution and to have access to all critical output, such as 2D wave spectra or Stokes drift at the surface to only name two examples. We present here an experimental campaign that was carried out during the deployment of the first two systems in the Pacific to A) validate the performance of both a GFS and CFSR forced wave model, 1000+nm from available NOAA buoys and B) intercompare the wave measurements from an unmanned surface vessel (USV) with those from wave buoys and a vessel based X-Band radar. The USV is the most feasible tool to collect long periods of data along the system trajectory and our preferred option in the long run. We zoom into one day to review in detail the various data sources, their comparability and employed post processing techniques. We present a preliminary comparison of integral wave parameters for the entire campaign (2272hrs/data points) and discuss further steps towards a more complete investigation. The preliminary comparison suggests that the USV and wave buoy data compare rather well. The largest differences are seen in wave periods. We obsen’e small differences between the GFS and CFSR forced model, both compare well with the field measurements.
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Gippius, Fedor, Fedor Gippius, Stanislav Myslenkov, Stanislav Myslenkov, Elena Stoliarova, Elena Stoliarova, Victor Arkhipkin und Victor Arkhipkin. „WAVE CLIMATE OF THE BLACK SEA’S COASTAL WATERS DURING THE LAST THREE DECADES“. In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.31519/conferencearticle_5b1b943584ab71.87772537.
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This study is focused on the alterations and typical features of the wind wave climate of the Black Sea’s coastal waters since 1979 till nowadays. Wind wave parameters were calculated by means of the 3rd-generation numerical spectral wind wave model SWAN, which is widely used on various spatial scales – both coastal waters and open seas. Data on wind speed and direction from the NCEP CFSR reanalysis were used as forcing. The computations were performed on an unstructured computational grid with cell size depending on the distance from the shoreline. Modeling results were applied to evaluate the main characteristics of the wind wave in various coastal areas of the sea.
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Gippius, Fedor, Fedor Gippius, Stanislav Myslenkov, Stanislav Myslenkov, Elena Stoliarova, Elena Stoliarova, Victor Arkhipkin und Victor Arkhipkin. „WAVE CLIMATE OF THE BLACK SEA’S COASTAL WATERS DURING THE LAST THREE DECADES“. In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b431636d688.
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This study is focused on the alterations and typical features of the wind wave climate of the Black Sea’s coastal waters since 1979 till nowadays. Wind wave parameters were calculated by means of the 3rd-generation numerical spectral wind wave model SWAN, which is widely used on various spatial scales – both coastal waters and open seas. Data on wind speed and direction from the NCEP CFSR reanalysis were used as forcing. The computations were performed on an unstructured computational grid with cell size depending on the distance from the shoreline. Modeling results were applied to evaluate the main characteristics of the wind wave in various coastal areas of the sea.
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Tahir, Zia ul Rehman, Muhammad Junaid Ali, Muhammad Asim, Syed Uzair Ahmad, Nasir Hayat, Afkar Hussain und Muhammad Azhar. „Evaluation of Solar Radiation from MERRA, MERRA-2, ERA-Interim and CFSR Reanalysis Datasets Against Surface Observations for Multan, Pakistan“. In ISES EuroSun 2018 Conference – 12th International Conference on Solar Energy for Buildings and Industry. Freiburg, Germany: International Solar Energy Society, 2018. http://dx.doi.org/10.18086/eurosun2018.09.04.
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Bento, A. Rute, Henrique Coelho und Chunxue Yang. „Evaluation of the Ocean Circulation for the Solomon Sea Using the Regional Ocean Modeling System (ROMS)“. In ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/omae2019-96179.
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Abstract The Regional Ocean Modeling System (ROMS) is a free-surface, terrain-following, primitive equations ocean model and it was implemented to perform a high-resolution 10-year hindcast study of Solomon’s Sea circulation patterns. The model was executed with a resolution of 1/36°, initial conditions from HYCOM+NCODA Global 1/12° and was forced by CFSR/CFSV2 momentum, mass and heat fluxes. The model was validated by comparing the simulated temperatures, salinities and flow patterns with satellite data, Argo floats and Ship ADCP measurements. In general, the model captured the main circulation patterns and performed well for the Solomon Sea. The modelled Temperature and Salinity profiles were comparable with the observations, with some error variability in the thermocline layer, which agreed with previous studies.