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O'Neill Z.,UTRC - United Technologies Research Center | Bailey T.,UTRC - United Technologies Research Center | Eisenhower B.,University of California at Santa Barbara | Fonoberov V.,Aimdyn, Inc
ASHRAE Transactions | Year: 2012

This article presents the calibration of a building energy model of a historic office building developed using the EnergyPlus simulation program. The building under study is the Fleet and Family Support Center located at Napal Station Great Lakes, IL. It was built in 1901 and renovated multiple times. This building has a total floor area of 36,843 ft2 (3424 m2) and mainly consists of offices and conference rooms. An extensive sensitivity study that efficiently perturbs more than two thousand model parameters is employed for model calibration. Those parameters that most affect the building's energy end-use are selected and automatically refined to calibrate the model by applying an analytic meta-model based optimization. Real time data including weather and energy meter data in 2010 is used for model calibration and 2011 data is used for model verification. The modeling process, calibration and verification results, as well as implementation issues encountered throughout the model calibration process from a user's perspective are discussed. The total facility and plug electricity consumption predictions from the calibrated EnergyPlus model match the actual measured monthly data within ±5%. ©2012 ASHRAE. Source


Fonoberova M.,Aimdyn, Inc | Fonoberov V.A.,Aimdyn, Inc | Mezic I.,University of California at Santa Barbara | Mezic J.,Aimdyn, Inc | Jeffrey Brantingham P.,University of California at Los Angeles
JASSS | Year: 2012

We perform analysis of data on crime and violence for 5,660 U.S. cities over the period of 2005-2009 and uncover the following trends: 1) The proportion of law enforcement officers required to maintain a steady low level of criminal activity increases with the size of the population of the city; 2) The number of criminal/violent events per 1,000 inhabitants of a city shows non-monotonic behavior with size of the population. We construct a dynamical model allowing for system-level, mechanistic understanding of these trends. In our model the level of rational behavior of individuals in the population is encoded into each citizen's perceived risk function. We find strong dependence on size of the population, which leads to partially irrational behavior on the part of citizens. The nature of violence changes from global outbursts of criminal/violent activity in small cities to spatio-temporally distributed, decentralized outbursts of activity in large cities, indicating that in order to maintain peace, bigger cities need larger ratio of law enforcement officers than smaller cities. We also observe existence of tipping points for communities of all sizes in the model: reducing the number of law enforcement officers below a critical level can rapidly increase the incidence of criminal/violent activity. Though surprising, these trends are in agreement with the data. Source


O'Neill Z.,UTRC - United Technologies Research Center | Eisenhower B.,University of California at Santa Barbara | Yuan S.,UTRC - United Technologies Research Center | Bailey T.,UTRC - United Technologies Research Center | And 2 more authors.
ASHRAE Transactions | Year: 2011

Calibrated energy models are useful for commissioning building systems, measurement and verification (M&V) of building retrofit projects, and predictions of savings from energy conservation measures. This paper presents the modeling and calibration process for building energy models of a DoD (Department of Defense) building. The models are developed using EnergyPlus and TRNSYS simulation programs with measured data from an enhanced building management system (BMS) which includes an on-site weather station. The building under study is the Atlantic Fleet Drill Hall located at Naval Station Great Lakes, IL. This LEED® Gold certified building with a total floor area of 69,218 ft 2 (6,431 m 2) consists of a drill deck and administrative offices. Static data from as-built drawings and dynamic data from building operations are collected and analyzed to create energy models with EnergyPlus and TRNSYS. An extensive sensitivity study by systematically perturbing more than a thousand model input parameters is employed for model calibration. Those parameters that most affect the building energy end-use are selected and refined to calibrate the models. The calibration results, as well as problems encountered throughout the process from the user's perspective, are discussed. The total facility and individual equipment electricity consumption predictions from the calibrated models closely match the measured data. © 2011 ASHRAE. Source


Fonoberova M.,Aimdyn, Inc | Fonoberov V.A.,Aimdyn, Inc | Mezic I.,University of California at Santa Barbara
Reliability Engineering and System Safety | Year: 2013

Agent-based models simulate simultaneous actions and interactions of multiple agents, in an attempt to re-create and predict the appearance of complex phenomena. We propose to use global sensitivity analysis as a tool for analyzing and evaluating agent-based models. A general approach for applying the global sensitivity analysis to agent-based models is presented and tested on the example of a socio-cultural agent-based model we developed earlier [45]. We identify the most significant parameters in the model and uncover their contributions to the outputs of interest. Methodology of model reduction for agent-based models is discussed and demonstrated for the aforementioned model. © 2013 Elsevier Ltd. Source


Zou Y.,Princeton University | Fonoberov V.A.,Aimdyn, Inc | Fonoberova M.,Aimdyn, Inc | Mezic I.,Aimdyn, Inc | And 2 more authors.
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2012

Agent-based modeling (ABM) constitutes a powerful computational tool for the exploration of phenomena involving emergent dynamic behavior in the social sciences. This paper demonstrates a computer-assisted approach that bridges the significant gap between the single-agent microscopic level and the macroscopic (coarse-grained population) level, where fundamental questions must be rationally answered and policies guiding the emergent dynamics devised. Our approach will be illustrated through an agent-based model of civil violence. This spatiotemporally varying ABM incorporates interactions between a heterogeneous population of citizens [active (insurgent), inactive, or jailed] and a population of police officers. Detailed simulations exhibit an equilibrium punctuated by periods of social upheavals. We show how to effectively reduce the agent-based dynamics to a stochastic model with only two coarse-grained degrees of freedom: the number of jailed citizens and the number of active ones. The coarse-grained model captures the ABM dynamics while drastically reducing the computation time (by a factor of approximately 20). © 2012 American Physical Society. Source

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