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IEEE-Power-and-Energy-Society General Meeting (PESGM)

作者： Ramasubramanian, Deepak Alvarez-Fernandez, Inalvis Mitra, Parag Gaikwad, Anish Boemer, Jens C. Elect Power Res Inst Grid Operat & Planning Grp Knoxville TN 37932 USA Univ Cent Florida Dept Elect & Comp Engn Orlando FL 32816 USA

ISBN: (纸本)9781728119816

With the spread of distribution connected inverters on a feeder being hidden from a transmission planner, the ability to represent the under voltage tripping characteristic of an aggregation of distribution inverters in a transmission planning study is becoming increasingly important. In this paper, parameters of the partial voltage trip characteristic of a recently approved positive sequence aggregated distributed energy resource model will be developed. In deriving these parameters, the uncertainty associated with the location of the inverters on the feeder, the impact of 1-phi transmission voltage events, and power imbalance across the feeder, will be considered. These variations are common variations that occur in the power system. The positive sequence aggregated model's behavior is compared with detailed 3-phi feeder level simulations performed on the IEEE 8500 node feeder.

关键词： aggregated distributed energy resources model parameterization single phase event

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Transistor-Level Analysis of Dynamic Delay models 25

Transistor-Level Analysis of Dynamic Delay Models

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25th IEEE International Symposium on Asynchronous Circuits and Systems (ASYNC)

作者： Maier, Juergen Fugger, Matthias Nowak, Thomas Schmid, Ulrich TU Wien ECS Grp Vienna Austria Univ Paris Saclay ENS Paris Saclay CNRS Paris France Univ Paris Saclay ENS Paris Saclay LSV Paris France INRIA Rocquencourt France Univ Paris Sud Paris France

ISBN: (纸本)9781538647479

Delay estimation is a crucial task in digital circuit design as it provides the possibility to assure the desired functionality, but also prevents undesired behavior very early. For this purpose elaborate delay models like the Degradation Delay model (DDM) and the Involution Delay model (IDM) have been proposed in the past, which facilitate accurate dynamic timing analysis: Both use delay functions that determine the delay of the current input transition based on the time difference T to the previous output one. Currently, however, extensive analog simulations are necessary to determine the (parameters of the) delay function, which is a very time-consuming and cumbersome task and thus limits the applicability of these models. In this paper, we therefore thoroughly investigate the characterization procedures of a CMOS inverter on the transistor level in order to derive analytical expressions for the delay functions. Based on reasonably simple transistor models we identify three operation regions, each described by a different estimation function. Using simulations with two independent technologies, we show that our predictions are not only accurate but also reasonably robust w.r.t. variations. Our results furthermore indicate that the exponential fitting proposed for DDM is actually only partially valid, while our analytic approach can be applied on the whole range. Even the more complex IDM is predicted reasonably accurate.

关键词： Circuit models glitch propagation delay models pulse degradation model parameterization

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Influence of Battery Parametric Uncertainties on the State-of-Charge Estimation of Lithium Titanate Oxide-Based Batteries

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ENERGIES 2018年第4期11卷 795-795页

作者： Shoe, Ana-Irina Meng, Jinhao Shoe, Daniel-Ioan Swierczynski, Maciej Teodorescu, Remus Kaer, Soren Knudsen Aalborg Univ Dept Energy DK-9220 Aalborg Denmark Northwestern Polytech Univ Sch Automat Xian 710072 Shaanxi Peoples R China

State of charge (SOC) is one of the most important parameters in battery management systems, as it indicates the available battery capacity at every moment. There are numerous battery model-based methods used for SOC estimation, the accuracy of which depends on the accuracy of the model considered to describe the battery dynamics. The SOC estimation method proposed in this paper is based on an Extended Kalman Filter (EKF) and nonlinear battery model which was parameterized using extended laboratory tests performed on several 13 Ah lithium titanate oxide (LTO)-basedlithium-ion batteries. The developed SOC estimation algorithm was successfully verified for a step discharge profile at five different temperatures and considering various initial SOC initialization values, showing a maximum SOC estimation error of 1.16% and a maximum voltage estimation error of 44 mV. Furthermore, by carrying out a sensitivity analysis it was showed that the SOC and voltage estimation error are only slightly dependent on the variation of the battery model parameters with the SOC.

关键词： lithium-ion batteries lithium titanate oxide (LTO) batteries hybrid pulse power characterization test model parameterization equivalent electrical circuit state of charge (SOC) extended Kalman filter

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The Role of Convective Gustiness in Reducing Seasonal Precipitation Biases in the Tropical West Pacific

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JOURNAL OF ADVANCES IN modelING EARTH SYSTEMS 2018年第4期10卷 961-970页

作者： Harrop, Bryce E. Ma, Po-Lun Rasch, Philip J. Neale, Richard B. Hannay, Cecile Pacific Northwest Natl Lab Atmospher Sci & Global Change Div Richland WA 99354 USA Natl Ctr Atmospher Res POB 3000 Boulder CO 80307 USA

Precipitation is an important climate quantity that is critically relevant to society. In spite of intense efforts, significant precipitation biases remain in most climate models. One pervasive and persistent bias found in many general circulation models occurs in the Tropical West Pacific where northern hemisphere summer-time precipitation is often underestimated compared to observations. Using the DOE-E3SM model, the inclusion of a missing process, convective gustiness, is shown to reduce those biases through a net increase in surface evaporation. Gustiness in surface wind fields is assumed to arise empirically in proportion to the intensity of convective precipitation. The increased evaporation can be treated as an increase in the moist static energy forcing into the atmosphere. A Normalized Gross Moist Stability (NGMS) framework (which characterizes the relationship between convective forcing and convective response) is used to explore the processes responsible for the precipitation bias, and the impact of the gustiness parameterization in reducing that bias. Because the NGMS of the Tropical West Pacific is less than unity in the E3SMv1 model, the increase in energy forcing amplifies the increase in precipitation to exceed that of the evaporative flux. Convective gustiness favors increased precipitation in regions where the resolved surface winds are weak and convection is present.

关键词： tropical precipitation model parameterization gross moist stability

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Application of a coupled model of photosynthesis and stomatal conductance for estimating plant physiological response to pollution by fine particulate matter (PM_2.5)

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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH 2018年第20期25卷 19826-19835页

作者： Yu, Weiqing Wang, Yujie Wang, Yunqi Li, Bai Liu, Yanju Liu, Xuan China Aviat Planning & Design Inst Grp Co Ltd Planning & Consultancy Inst 12 Deshengmenwai St Beijing Peoples R China Beijing Forestry Univ Key Lab Soil & Water Conservat & Desertificat Com Minist Educ 35 Qinghua East Rd Beijing Peoples R China Beijing Forestry Univ Sch Soil & Water Conservat 35 Qinghua East Rd Beijing Peoples R China China Inst Water Resources & Hydropower Res Dept Sedimentat 20 Chegongzhuang West Rd Beijing Peoples R China Minist Water Resource Res Ctr Soil & Water Conservat 20 Chegongzhuang West Rd Beijing Peoples R China Obermeyer Engn Consulting Beijing Co Ltd C2 Dongsanhuan North Rd Beijing Peoples R China

Fine particulate matter (PM2.5) is a current environmental issue that has an impact on the global ecology. Vegetation is a known sink for PM2.5 deposition but the effects of these particles on plant growth, and specifically on plant photosynthesis by changing their leaf water potential, are still not well understood. This study aimed to determine and characterize possible relationships between PM2.5 and plant photosynthesis under different PM2.5 concentrations. Both indoor and outdoor measurements were carried out to evaluate the variation dynamics of net photosynthetic rate and stomatal conductance of four plant species with different leaf characteristics under different PM2.5 levels. A calibrated coupled model of photosynthesis and stomata(conductance was developed to estimate the relationship between plant photosynthesis and PM2.5 reliably. Net photosynthetic rate and stomatal conductance declined over time at elevated PM2.5, with large variations with PM2.5 concentrations. Using a calibrated model of photosynthesis coupled to stomatal conductance, we show that PM2.5 can influence plant photosynthesis that primarily occurs through the stomata on leaves. Although the effect of particles on plant photosynthesis was not as high as that of photosynthetically active radiation, temperature, and CO2 concentration around the leaf, the effect from PM2.5 can be significant, in particular, in highly polluted atmospheres.

关键词： PM2.5 Leaf characteristics Net photosynthetic rate Stomatal conductance Photosynthesis model model parameterization

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Soil and Water Assessment Tool model predictions of annual maximum pesticide concentrations in high vulnerability watersheds

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INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2018年第3期14卷 358-368页

作者： Winchell, Michael F. Peranginangin, Natalia Srinivasan, Raghavan Chen, Wenlin Stone Environm Montpelier VT 05602 USA Syngenta Crop Protect Greensboro NC USA Texas A&M Univ Spatial Sci Lab Dept Ecosyst Sci & Management College Stn TX USA

Recent national regulatory assessments of potential pesticide exposure of threatened and endangered species in aquatic habitats have led to increased need for watershed-scale predictions of pesticide concentrations in flowing water bodies. This study was conducted to assess the ability of the uncalibrated Soil and Water Assessment Tool (SWAT) to predict annual maximum pesticide concentrations in the flowing water bodies of highly vulnerable small- to medium-sized watersheds. The SWAT was applied to 27 watersheds, largely within the midwest corn belt of the United States, ranging from 20 to 386km(2), and evaluated using consistent input data sets and an uncalibrated parameterization approach. The watersheds were selected from the Atrazine Ecological Exposure Monitoring Program and the Heidelberg Tributary Loading Program, both of which contain high temporal resolution atrazine sampling data from watersheds with exceptionally high vulnerability to atrazine exposure. The model performance was assessed based upon predictions of annual maximum atrazine concentrations in 1-d and 60-d durations, predictions critical in pesticide-threatened and endangered species risk assessments when evaluating potential acute and chronic exposure to aquatic organisms. The simulation results showed that for nearly half of the watersheds simulated, the uncalibrated SWAT model was able to predict annual maximum pesticide concentrations within a narrow range of uncertainty resulting from atrazine application timing patterns. An uncalibrated model's predictive performance is essential for the assessment of pesticide exposure in flowing water bodies, the majority of which have insufficient monitoring data for direct calibration, even in data-rich countries. In situations in which SWAT over- or underpredicted the annual maximum concentrations, the magnitude of the over- or underprediction was commonly less than a factor of 2, indicating that the model and uncalibrated parameterization approach p

关键词： SWAT model Pesticide exposure Ecological risk assessment model parameterization modeling monitoring comparison

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Measuring root system traits of wheat in 2D images to parameterize 3D root architecture models

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PLANT AND SOIL 2018年第1-2期425卷 457-477页

作者： Landl, Magdalena Schnepf, Andrea Vanderborght, Jan Bengough, A. Glyn Bauke, Sara L. Lobet, Guillaume Bol, Roland Vereecken, Harry Forschungszentrum Juelich GmbH Agrosphere IBG 3 D-52428 Julich Germany James Hutton Inst Dundee DD2 5DA Scotland Univ Dundee Sch Sci & Engn Dundee DD1 4HN Scotland Univ Bonn Inst Crop Sci & Resource Conservat INRES Soil Sci Nussallee 13 D-53115 Bonn Germany

Background and aims The main difficulty in the use of 3D root architecture models is correct parameterization. We evaluated distributions of the root traits inter-branch distance, branching angle and axial root trajectories from contrasting experimental systems to improve model parameterization. Methods We analyzed 2D root images of different wheat varieties (Triticum aestivum) from three different sources using automatic root tracking. model input parameters and common parameter patterns were identified from extracted root system coordinates. Simulation studies were used to (1) link observed axial root trajectories with model input parameters (2) evaluate errors due to the 2D (versus 3D) nature of image sources and (3) investigate the effect of model parameter distributions on root foraging performance. Results Distributions of inter-branch distances were approximated with lognormal functions. Branching angles showed mean values < 90 degrees. Gravitropism and tortuosity parameters were quantified in relation to downwards reorientation and segment angles of root axes. Root system projection in 2D increased the variance of branching angles. Root foraging performance was very sensitive to parameter distribution and variance. Conclusions 2D image analysis can systematically and efficiently analyze root system architectures and parameterize 3D root architecture models. Effects of root system projection (2D from 3D) and deflection (at rhizotron face) on size and distribution of particular parameters are potentially significant.

关键词： Axial root trajectories Branching angle Foraging performance Inter-branch distance model parameterization Root system architecture

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Sensitivity analyses of acoustic impedance inversion with full-waveform inversion

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JOURNAL OF GEOPHYSICS AND ENGINEERING 2018年第2期15卷 461-477页

作者： Yao, Gang da Silva, Nuno V. Wu, Di Imperial Coll London Dept Earth Sci & Engn London SW7 2BP England China Univ Petr Unconvent Nat Gas Inst Beijing 102249 Peoples R China

Acoustic impedance estimation has a significant importance to seismic exploration. In this paper, we use full-waveform inversion to recover the impedance from seismic data, and analyze the sensitivity of the acoustic impedance with respect to the source-receiver offset of seismic data and to the initial velocity model. We parameterize the acoustic wave equation with velocity and impedance, and demonstrate three key aspects of acoustic impedance inversion. First, short-offset data are most suitable for acoustic impedance inversion. Second, acoustic impedance inversion is more compatible with the data generated by density contrasts than velocity contrasts. Finally, acoustic impedance inversion requires the starting velocity model to be very accurate for achieving a high-quality inversion. Based upon these observations, we propose a workflow for acoustic impedance inversion as: (1) building a background velocity model with travel-time tomography or reflection waveform inversion;(2) recovering the intermediate wavelength components of the velocity model with full-waveform inversion constrained by Gardner's relation;(3) inverting the high-resolution acoustic impedance model with short-offset data through full-waveform inversion. We verify this workflow by the synthetic tests based on the Marmousi model.

关键词： acoustic impedance full-waveform inversion model parameterization short offset reflection

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modeling sensitivity of grain yield to elevated temperature in the DSSAT crop models for peanut, soybean, dry bean, chickpea, sorghum, and millet

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EUROPEAN JOURNAL OF AGRONOMY 2018年 100卷 99-109页

作者： Boote, K. J. Prasad, Vara Allen, L. H., Jr. Singh, P. Jones, J. W. Univ Florida Agr & Biol Engn Dept Gainesville FL 32611 USA Kansas State Univ Manhattan KS 66506 USA USDA ARS Washington DC 20250 USA Int Crops Res Inst Semi Arid Trop Hyderabad Telangana India

Crop models are increasingly being used as tools to simulate climate change effects or effects of virtual heat-tolerant cultivars;therefore it is important that upper temperature thresholds for seed-set, seed growth, phenology, and other processes affecting yield be developed and parameterized from elevated temperature experiments whether field or controlled-environment chambers. In this paper, we describe the status of crop models for dry bean (Phaseolus vulgaris L.), peanut (Arachis hypogaea L.), soybean (Glycine max L.), chickpea (Cicer arietinum L.), sorghum (Sorghum bicolor (L) Moench), and millet (Pennisetum glaucum L. (R.) Br) in the Decision Support System for Agrotechnology Transfer (DSSAT) for response to elevated temperature by comparison to observed data, and we review where changes have been made or where needed changes remain. Temperature functions for phenology and photosynthesis of the CROPGRO-Dry Bean model were modified in 2006 for DSSAT V4.5, based on observed growth and yield of Montcalm cultivar grown in sunlit, controlled-environment chambers. Temperature functions for soybean and peanut models were evaluated against growth and yield data in the same chambers and found to adequately predict growth and yield, thus have not been modified since 1998 release of V3.5. The temperature functions for the chickpea model were substantially modified for many processes, and are updated for V4.6. The millet model was re-coded and modified for its temperature sensitivities, with a new function to allow the 8-10 day period prior to anthesis to affect grain set, as parameterized from field observations. For the sorghum model, the temperature effect on grain growth rate was modified to improve yield and grain size response to elevated temperature by comparison to data in controlled-environment chambers. For reliable assessments of climate change impact, it is critically important to gather additional temperature response data and to update parameterization and

关键词： DSSAT Crop modeling model parameterization Elevated temperature Grain-set Grain growth rate Photosynthesis

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New Perspectives in Clinical Pharmacokinetics-1: the Importance of Updating the Teaching in Pharmacokinetics that both Clearance and Elimination Rate Constant Approaches Are Mathematically Proven Equally Valid

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AAPS JOURNAL 2018年第2期20卷 1-5页

作者： Jelliffe, Roger Bayard, David Univ Southern Calif USC Lab Appl Pharmacokinet & Bioinformat Sch Med Childrens Hosp Los Angeles 4650 Sunset Blvd51 Los Angeles CA 90027 USA

The healing professions have only about four main therapeutic tools at their disposal-surgery, drugs, physical therapy, and psychotherapy. For the general profession of internal medicine, drug therapy is its primary tool. Providing an understanding of the state-of-the-art in therapeutic methods, grounded in solid scientific and mathematical rigor, is therefore of the utmost clinical importance for both physicians and clinical pharmacists. This is particularly true where rapidly evolving scientific changes require an up-to-date education upon which students can rely. Unfortunately, relatively little attention has been paid to training clinical pharmacokineticists and physicians to manage drug therapy optimally for patients under their care in their everyday practice. In this paper, we discuss one of these basic deficiencies from the perspective of the longstanding controversy in pharmacokinetic modeling: whether the volume and clearance approach or the volume and rate constant approach is somehow "better". We examine this controversy using the mathematical principle of invariance, which to our knowledge has not been done before. The conclusion of this analysis is that both approaches are rigorously proven mathematically to be equally valid. We also discuss some implications of these equally valid approaches from the framework of mechanistic and non-compartmental models. Ultimately, the conclusion is that the choice of one parameterization over the other is based on preference or usefulness for research or clinical practice, but no longer, because of this analysis, on science.

关键词： clearance model parameterization pharmacokinetics rate constant

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