Computer Engineering Commons^™

Trade-Offs Of Biogas Production: Comparing Crop Ro­Tations Under Different Climate Scenarios, Sven Lautenbach, Martin Volk, Micheal Strauch, Gerald Whittaker, Ralf Seppelt

International Congress on Environmental Modelling and Software

While increasing biofuel production is worldwide on the political agenda, concerns about the involved trade-offs are on the rise. However, the quantification of these trade-offs is typically based on the comparison of a limited number of plausible alternatives. We extended the analysis by applying a multi-objective genetic algorithm to estimate the set of Pareto optimal solutions which de­scribe the trade-offs between the objectives. The Pareto solutions represent the (estimated) best op­tions given the model and the specified control options. Our analysis studied food and fodder based crop rotations and two alternative biogas crop production schemes: a corn based production scheme …

The Differential Vector Phase-Locked Loop For Global Navigation Satellite System Signal Tracking, James J. Brewer

Theses and Dissertations

A novel differential vector phase-locked loop (DVPLL) is derived that takes GNSS code-phase and carrier-phase measurements from a base station and uses them to maintain an integer ambiguity resolved quality solution directly in the vector tracking loop of a rover receiver. The only state variables estimated and used to create the replica code and carrier signals from the base station measurements are three position and two clock states for a static test. Closing the individual loops solely through the navigation filter makes this a pure vector method. For short baselines, where differential atmospheric errors are small, the DVPLL can be …

Scalable System Design For Covert Mimo Communications, Jason R. Pennington

Theses and Dissertations

In modern communication systems, bandwidth is a limited commodity. Bandwidth efficient systems are needed to meet the demands of the ever-increasing amount of data that users share. Of particular interest is the U.S. Military, where high-resolution pictures and video are used and shared. In these environments, covert communications are necessary while still providing high data rates. The promise of multi-antenna systems providing higher data rates has been shown on a small scale, but limitations in hardware prevent large systems from being implemented.

An R Package For Implementing Multiple Evapotranspiration Formulations, Danlu Guo, Seth Westra, Holger R. Maier

International Congress on Environmental Modelling and Software

The use of multiple evapotranspiration (ET) models is critical for exploring the ambiguity in the representations of ET processes. Although ensemble ET models are increasingly used to address this ambiguity, practical issues include: 1) the diversity of process representations, which require different input data and constants; 2) the diversity of nomenclature, terminology and units used in the literature; and 3) the complexity of some formulations, requiring significant time for coding and leading to potential user errors. We describe an R package that estimates both actual and potential ET from 17 well-known formulations. Results are presented as summary text and plots, …

Using Locally Distributed Computing To Aid Water Quality Modelling, Saurav Kumar, Adil N. Godrej, Thomas J. Grizzard

International Congress on Environmental Modelling and Software

Watershed managers and other experts frequently use water quality models to manage and study watershed-waterbody systems. Many modern water quality models have become increasingly complex and require significant amount of computational resources to execute. This situation is further exacerbated by linked models, which require sequential execution of multiple models to simulate the entire system, along with data conversion to transfer data between the linked models. Many tasks, such as evaluations of the robustness of the modelling system through sensitivity analysis and applications of water quality models as a tool to aid decision-making, require multiple executions of water quality models and …

Characterizing Spatial Random Fields Through A Bayesian Inverse Modeling Framework And The High Throughput Computing Software - Htcondor, Carlos Osorio-Murillo, Daniel P. Ames, Heather Frystacky, Yoram Rubin

International Congress on Environmental Modelling and Software

Spatial Random Fields (SRFs) are used to characterize the behavior of variables which are difficult to measure everywhere. In the case of hydraulic conductivity used in groundwater models, heterogeneity can be modeled through structural parameters of the random fields – parameters that define the field’s spatial distribution. Characterization of these structural parameters using a stochastic inverse method requires the evaluation of thousands of potential realizations of the SRF which is a time consuming and challenging task – reducing the adoption of stochastic models. To address this issue, this paper presents the integration of high throughput computing using HTCondor with the …

Parallel Simulation Of Environmental Phenomena, Ralf Denzer, Peter Fitch, Ioannis N. Athanasiadis, Daniel P. Ames

International Congress on Environmental Modelling and Software

This paper discusses the current situation with respect to the parallel simulation of environmental phenomena. It is not based on a complete and thorough investigation of the state-of- the-art in this domain and is more driven by observations, experiences and ideas of the four contributors who see the need to raise awareness towards a more systematic approach in the future. It is meant as a discussion paper to stimulate a more systematic approach towards parallel simulation in the environmental domain. While examples are mostly taken from hydrology, they are only used as illustration of a generic situation. The section on …

Software Engineering For Scientific Application: Effort Report On The Community Land Model Within The Earth System Modeling Framework, Dali Wang, Yang Xu

International Congress on Environmental Modelling and Software

One key factor in the improved understanding of earth system science is the development and improvement of high fidelity models. Along with the deeper understanding of earth system processes, the software complexity of those modelling systems becomes a barrier for further rapid model improvements and validation. In this paper, we present our experience on better understanding of the community land model (CLM) within an earth system modeling framework. After the science and software background of CLM, we represent three groups of CLM software engineering practices, which aim to 1) better understand the software system for rapid software system development on …

Balancing Externalities And Industrial Costs In Air Quality Planning, Claudio Carnevale, Giorgio Guariso, Enrico Pisoni, Marialuisa Volta

International Congress on Environmental Modelling and Software

When adopting regional plans aimed at improving air quality, environmental authorities are often faced with the relevant costs that the adoption of abatement measures implies. On the other hand, scientific literature has well documented damages due to air pollution impact on human health and ecosystems. This paper proposes a tool that allows balancing these two viewpoints by defining the efficient set of measures in a multi-objective perspective. Despite both external (health related) and internal (industrial/emission abatement related) costs can be measured in the same unit, namely money, it appears unacceptable to add them together as in a cost-benefit analysis, since …

Estimation Of Pahs Concentration Fields In An Urban Area By Means Of Support Vector Machines, Armando Pelliccioni, Andrea Cristofari, Camillo Silibello, Monica Gherardi, Angelo Cecinato, Mafalda Lamberti

International Congress on Environmental Modelling and Software

Epidemiological studies about health effects of air quality are often based on data inferred by monitoring stations, and the issue of constructing pollutants exposure maps is crucial for improving such studies. The study about Polycyclic Aromatic Hydrocarbons (PAHs) exposure in urban areas is the aim of the EXPAH LIFE+ Project, so an integrated approach, based on measurements and modeling techniques, has been applied to simulate PAHs concentration in the urban area of Rome in one year period (June 2011 - May 2012). Support Vector Machines (SVMs) have been applied to forecast PAHs concentrations starting from actual measurements. After a feature …

Use Of Low-Cost Particle Monitors To Calibrate Traffic­-Related Air Pollutant Models In Urban Areas, Edmund Seto, Elena Austin, Igor Novosselov, Micheal Yost

International Congress on Environmental Modelling and Software

The availability of new small and low-cost particulate matter monitors has enabled the collection of large quantities of data to calibrate traffic-related air pollution models in urban areas. We present laboratory findings on the performance of our Portable University of Washington Particle (PUWP) monitor compared to a reference instrument, and its application to air quality modeling for epidemiologic studies. The instrument has been calibrated in laboratory chamber studies as well as in field collocation studies against reference instruments. We are currently examining the use of the PUWP to calibrate air pollution. In our laboratory studies, four PUWP monitors were placed …

Modelling The Impact Of Microbial Loop On Aquatic Food Webs, Yu Li, Liancong Luo, Vardit Makler-Pick, Emily K. Read, Matthew R. Hipsey

International Congress on Environmental Modelling and Software

In order to control algal blooms, it is necessary to better understand microbial interactions in aquatic ecosystems. Based on the traditional "Nutrients-Phytoplankton-Zooplankton-Detritus" (NPZD) model, the "Nutrients-Phytoplankton-Zooplankton-Detritus+Bacteria" (NPZD+B) model has been developed to investigate the impact of the microbial loop on aquatic food webs via nutrient cycling processes. The results of the NPZD+B model showed the positive impact of the microbial loop on phytoplankton growth, and illustrated the importance of "bottom-up" (resource) control of algal blooms in aquatic ecosstems. The study concludes that the microbial loop is an important model component for simulating water quality dynamics when nutrients are limited in …

Statistical Evaluation Of Intra-Event Variability Of Fecal Indicator In Stormwater Runoff From Different Land Uses, Ma. Cristina A. Paule, Sheeraz Memon, Bum-Yeon Lee, Umer S. Raja, Chinzorig Sukhbaatar, Jey-R S. Ventura, Deokjin Jahng, Joo-Hyon Kang, Chang-Hee Lee

International Congress on Environmental Modelling and Software

Stormwater runoff is one of the major transporters of fecal indicator bacteria (FIB) contaminant in the downstream areas. The development of models to predict FIB concentrations in stormwater runoff are important because it is impractical to monitor and analyze every different microorganism at all monitoring sites. Understanding the correlation of hydrological characteristics such as antecedent dry days (ADD), total rainfall (RAIN), average rainfall intensity (AVGINT), runoff duration (RUNDUR) and runoff volume (RUNVOL), is important in development of such models. In this study, the samples were collected from three different monitoring sites which include agriculture (Site 1); mixed catchment (site 2) …

Long-Term Numerical Simulation For Stability Within The River Mouth; Case Study: Rosetta Promontory, Egypt, Ali Masria, Abdelazim Negm, Moheb Iskander, Oliver C. Saavedra, M. A. Bek

International Congress on Environmental Modelling and Software

Estuaries are very sensitive and vulnerable to any interventions in coastal dynamics. Most of these inlets experience coastal problems such as severe erosion and accretion. Rosetta promontory, Egypt, is an example of such an environment. It suffers from coastline erosion and sedimentation inside the inlet. The shoaling of the inlet leads to hindering the navigation process of fishing boats, negative impacts to estuarine and salt marsh habitat and decreases the efficiency of the cross section to transferring the flood flow to the sea.

This paper aims to reach a new condition of stability of Rosetta Promontory by using coastal measures. …

Varying The Temporal Resolution Of River Nutrient Boundary Conditions To A Coupled Hydrodynamic-Biogeochemical Model Of A Coastal System Has Surprisingly Little Impact On Model Results, Barbara J. Robson, Jenny Skerratt, Mathieu Mongin, Karen Wild-Allen, Mark Baird

International Congress on Environmental Modelling and Software

Differences in the temporal resolution of catchment models and receiving water models often represent a problem for coupling of these models. Many catchment models are optimised for prediction of event-mean, monthly, or average annual sediment and nutrient loads, while coupled biogeochemical-hydrodynamic models typically run on time-steps measured in seconds, and often aim to predict patterns on a day-to-day or even sub-daily time-scale. Though previous work has shown that low temporal resolution of river boundary conditions set from in situ measurements can compromise the accuracy of a receiving water model, this is in large part because total river loads derived from …

Using Geostatistical Tools For Mapping Traffic-Related Air Pollution In Urban Areas, Lubos Matejicek

International Congress on Environmental Modelling and Software

Air pollution sources caused by increasing road traffic reduce air quality and affect people in urban areas. In order to improve living conditions in urban areas, predictions of effects on air pollution are needed for assessing exposures as part of epidemiological studies, and to inform urban air-quality policy and traffic management. A prediction system for estimation, analysis and visualization has been developed to model spatial patterns of traffic-related air pollution. In this study, several geostatistical techniques are used for prediction of NO₂ and PM₁₀. The primary data for geostatistical methods originate from sample points that are generated …

Enhancing User Customization Through Novel Software Architecture For Utility-Scale Solar Siting Software, Brant Peery, R. Sam Alessi, Randy D. Lee, Leng Vang, Scott Brown, David Solan, Dan Ames

International Congress on Environmental Modelling and Software

The need exists for a spatial decision support application that allows users to create customized metrics for comparing proposed locations of a new solar installation. This document discusses how PVMapper was designed to overcome the customization problem through development of loosely coupled spatial and decision components in a JavaScript plug-in architecture, allowing the user to easily add functionality and data to the system. The paper also explains how PVMapper provides the user with a dynamic and customizable decision tool that enables them to visually modify the formulas that are used in the decision algorithms that convert data to comparable metrics. …

Cyberinfrastructure For Scalable Access To Stream Flow Analysis, Tyler Wible, Wes Lloyd, Olaf David, Mazdak Arabi

International Congress on Environmental Modelling and Software

Traditionally the various components of flow analysis including flooding, drought, base-flow, pollutant loading, and duration curves have been examined independently by various analysis methods or software packages. A better approach would be to combine these multiple packages into a single web-tool to improve access. Infrastructure-as-a-Service (IaaS) cloud provides a scalable infrastructure for model implementation, which is a necessity of web services due to the characteristics of web traffic. IaaS centralizes the computational burden and overhead of multiple model runs from local computers to online servers. This paper demonstrates the scalability benefits of the Comprehensive Flow Analysis (CFA) tool in an …

State And Trends In Mobile Observation Applications, Denis Havlik, Gerald Schimak

International Congress on Environmental Modelling and Software

The stellar growth of the smartphones and nearly gapless mobile network coverage in urban and suburban areas has widely extended the potential of the citizens' observatories. The possibility to easily record observations made by mobile citizens, and to automatically enrich this information using the built-in and external sensors sounds like a dream come true of the scientists and decision makers alike. However, in 2013 only a tiny portion of the potential users really participated in the citizen observation programs and the usability of the received information is often below expectations. The learning curve is often too high, sensor quality too …

Should Hydro-Economic Models Be Agent-Based? Should They Include Non-Economic Behaviors And Metrics?, Julien J. Harou

International Congress on Environmental Modelling and Software

Hydro-economic analysis represents the standard hydrological and engineering realities of water resource system along-side economic drivers and impacts. Often optimization is used to simulate profit-maximizing behavior which is assumed to drive most water use decisions. Recently, different modeling trends have bumped against traditional hydro-economic modeling and challenging it in new directions. One is agent-based modeling, understood as a field of analysis where the behavioral rules of individuals help understand/predict how the whole system functions. This challenges hydro-economic models to include non-economic driven rules or behaviors in addition to economic optimization. Multi-criteria optimization also challenges social-economic models to assess other performance …