Digital Commons Network^™

Reinforcement Learning For Building Management Systems, Parastoo Delgoshaei, Amanda Pertzborn, Mohammad Heidarinejad

International High Performance Buildings Conference

It is increasingly common to design buildings with advanced sensing and control systems to improve energy efficiency, indoor air quality which impacts health and productivity. However, there has been limited progress in making building automation systems “intelligent,” as the performance of such buildings is often limited by reactive control systems, primarily using setpoint limits and fixed operation schedules. The complex nature of building control problems motivates the application of state-of-the-art software engineering methods and techniques. Agent-based models (ABM) are well-suited for controlling complex engineering systems such as those employed in building heating, ventilation, and air-conditioning (HVAC) systems. In this paradigm, …

A Practical Data-Driven Multi-Model Approach To Model Predictive Control: Results From Implementation In An Institutional Building, Etienne Saloux, Nunzio Cotrufo, José Candanedo

International High Performance Buildings Conference

Model-based Predictive Control (MPC) is an effective solution to improve building controls. It consists of the use of weather and occupancy forecasts along with a control-oriented model to predict the behaviour of the building a few hours or days ahead, and thus optimize the operation of its systems. Although the potential of MPC is widely recognized, and plentiful operational data is often available, the development of a model requires a great deal of effort, significant technical expertise and knowledge of building systems. The challenge of creating a model is a hurdle that makes the on-site implementation of MPC in buildings …

Recurrent Neural Network-Based Economic Mpc Applied To Building Hvac Systems, Matthew Ellis, Venkatesh Chinde

International High Performance Buildings Conference

No abstract provided.

A Numerical Study On The Pool Boiling With Foam Surface Enhancement Using Different Refrigerants, Mingkan Zhang, Kashif Nawaz, Cheng-Min Yang, Matthew Sandlin, William Asher, Brian Fricke, Anthony Gehl

International Refrigeration and Air Conditioning Conference

The pool boiling process can be observed in several energy conversion processes including commercial and industrial refrigeration, industrial air-cooling operations, and power generation. The process becomes more involved when pool boiling in a tube bundle is considered. In the current study, a numerical model is developed to predict the key performance parameters of a flooded evaporator while considering a range of working fluids. A kettle reboiler configuration was considered, and a performance model was developed to account for boiling on individual tubes, merging of vapor bubbles, and movement under gravity. A volume of fluid (VOF) model was used to deal …

Modeling And Analysis Of Pressure Drop Oscillations In Horizontal Boiling Flow, Hongtao Qiao, Christopher Laughman

International Refrigeration and Air Conditioning Conference

In general, two-phase flow phenomena can be described based on the one-dimensional conservation laws. Models with different formulations can be obtained with different assumptions. This paper presents three models with different complexity to simulate pressure drop oscillations. The direct comparison indicates that there are substantial differences between these models. The mechanism of pressure drop oscillations is discussed and the effect of operating parameters on system instability is explored. It is shown that two bifurcation points can exist when varying heat input and inlet subcooling. Root locus analysis corroborates the simulation results.

Comprehensive Study Of Heat Transfer And Pressure Drop In Regenerator And Optimization Of Solid-State Caloric Cooling Cycles Using Realistic Hydraulic Diameter Of Regenerator, Minwoong Kang, Stefan Elbel

International Refrigeration and Air Conditioning Conference

Many researchers have used very small hydraulic diameters in regenerators of solid-state caloric cooling cycles, because smaller diameters can generate higher cooling capacity and system COP. However, using very small diameters hardly represent the real performance of the caloric cooling cycle, because they cannot be manufactured for a real system. Therefore, this paper has used more realistic hydraulic diameter which is used in commercial heat exchangers. To get the more accurate heat transfer coefficient and friction factor, the model used in this paper incorporates hydrodynamic and thermal developing regions which are usually neglected in other papers. This paper shows that …

Reflections On Asset-Based Pre-College Engineering Education To Promote Equity: An Introduction To The Special Issue, Lee Martin, Kristen B. Wendell

Journal of Pre-College Engineering Education Research (J-PEER)

In our call for proposals, we argued that engineering education is in need of a paradigm shift that takes students’ assets as epistemologically primary to our conception of what engineering, and engineering education, can and should be. The 12 papers collected in this special issue show how a focus on youth assets can realign engineering education to be more humane, more inclusive, and just as meaningful as that of a traditional model. The papers offer both theoretical argumentation and empirical evidence to support their answers to the question of how asset-based approaches can improve engineering education. An emergent theme in …

Developing A Framework For Determining Optimum Dispatch Of Energy To A Building From Conventional And Renewable Sources, Sultan Ahmad, William Travis Horton

International High Performance Buildings Conference

In an optimally designed grid-connected system with distributed energy resources where the grid plays the role of an energy buffer, it is interesting to analyze the economic feasibility to employ energy storage systems. A grid-connected system synchronizes with the power fluctuations, lowering the costs of energy compared to the cost of using conventional energy storage systems. An adaptive code is developed using computer programming that is used for lifetime simulation of the energy dispatch system with a specified time step and for optimization algorithm with comprehensive reliability/cost assessment. The results can be extended to a long period considering various economic …

Effect Of The Refrigerant Charge On The System Performance And Mass Distribution In Air-To-Water Heat Pumps, Costantino Guzzardi, Marco Azzolin, Sandro Lazzarato, Davide Del Col

International Refrigeration and Air Conditioning Conference

Recent regulations in the matter of climate change and environmental protection are pushing to reduce the release of greenhouse gases into the atmosphere. The overall environmental impact of a refrigeration system can be reduced by optimizing and possibly minimizing the amount of refrigerant charge in the system. Even in the case of natural and low-GWP synthetic refrigerants, due to the well-known problems with toxicity and flammability, it is required to minimize the amount of refrigerant charged into the system to reduce the associated risks. The charge minimization process requires to know the refrigerant distribution to identify and redesign the critical …

The Study On Dynamic Characteristics Of Twin-Screw Compressor Rotor, Baoshun Xiong, Huagen Wu, Kanlong Lin, Beiyu Zhang

International Compressor Engineering Conference

In the working process of twin-screw compressor, the rotors are subjected to multiple physical effects of the gas temperature, pressure and force, and presents a periodic change. In this paper, three-dimensional Computational Fluid Dynamics (CFD) simulation of screw compressor is carried out, and the characteristics of temperature distribution, pressure distribution and gas force distribution on the rotors’ surface are studied. Firstly, the rotor domain, suction and exhaust face grids are generated by TwinMesh, and then they are imported into the CFX calculation model. Through the fluid-structure interaction analysis and calculation, the strain shape of the screw rotor under the multiple …

A Nonlinear Model Order Reduction Framework For Dynamic Vapor Compression Cycles Via Proper Orthogonal Decomposition, Jiacheng Ma, Donghun Kim, James E. Braun

International Refrigeration and Air Conditioning Conference

A computationally efficient and accurate modeling approach is critically important for designing and evaluating controls and fault detection and diagnosis (FDD) algorithms. This paper proposes a reduced order modeling approach for vapor compression cycles (VCC) that involves application of nonlinear model order reduction (MOR) methods to dynamic heat exchanger (HX) models to generate reduced order HX models. A reformulated finite volume HX model was first developed that matches the baseline MOR model structure. Then, a nonlinear MOR framework based on Proper Orthogonal Decomposition (POD) and a Discrete Empirical Interpolation Method (DEIM) was developed for generating nonlinear reduced order HX models. …

Superheat Prediction & Fault Diagnostics Of Hvac From Simple Temperature Measurements Using Big Data Approach, Mehari Tesfay, Fadi Alsaleem, Kevin Sinkar, Parthiban Arunasalam

International High Performance Buildings Conference

No abstract provided.

A Modeling Approach To Characterize The Demand Flexibility Of The Air Distribution System In Commercial Buildings, Elvin Vindel, Mario Berges, Burcu Akinci

International High Performance Buildings Conference

Commercial VAV systems have been a studied as potential flexible power consumption resources to provide these services. A significant limitation is the development of control oriented models for these systems that accurately control power consumption across timescales. To this end, we develop a modeling approach that characterizes the demand flexibility of the air distribution system in commercial buildings. The model maps all feasible terminal zone damper configurations to power consumption by identifying a system resistance model connected to a pressure-flow model of the supply fan. Under this model structure, the operational range of an installed system can be quantitatively bounded …

Modelling And Simulation Of A Flash Tank Vapour Injection Heat Pump In Several Platforms, Viren Bhanot, Paolo Petagna, Andrea Cioncolini, Jiazhen Ling, Vikrant Aute

International Refrigeration and Air Conditioning Conference

In this paper, we model a relatively complex flash tank vapour injection heat pump using the physical modelling software EcosimPro. The heat pump was extensively tested in a previous study and a variety of system parameters were made available for validation. Simulation results are compared against measured data as well as against two other platforms: Dymola and Simulink. Startup and step-change transients have been simulated. The discrepancies between the different models are used to highlight some important aspects in conducting dynamic thermo-fluid simulations. In particular, although qualitatively representative trends may be reproduced, there is an unavoidable need to first obtain …

Time Decay: Assets, Authoritarianism, And Anxiety About The Future, Jack Davies

CLCWeb: Comparative Literature and Culture

This article identifies a basic formula in the Freudo-Marxist take on twentieth-century authoritarianism. This is the incommensurability of inherited past development with the pace and demands of industrial social life, damming up a tremendous excess that seeks reactionary outlet. Authoritarianism, here, breeds in the contradiction between the symptoms of the Oedipal drama and the commodity form. The implicit “repressive hypothesis” for sexuality and developmentalist teleology make this theorization of authoritarian formations untenable today. This article, however, identifies moments of promise in this literature, and turns to materials available to these thinkers—specifically interwar psychoanalytic theory on anxiety and economic theory on …

Factors Influencing Student Stem Learning: Self-Efficacy And Outcome Expectancy, 21st Century Skills, And Career Awareness, Jung Han, Todd R. Kelley, J. Geoff Knowles

Technology Leadership and Innovation Faculty Publications

Social, motivational, and instructional factors impact students’ outcomes in STEM learning and their career paths. Based on prior research and expectancy-value theory, the study further explored how multiple factors affect students in the context of integrated STEM learning. High school STEM teachers participated in summer professional development and taught integrated STEM to students during the following school year, where scientific inquiry, biomimicry, 3D printing technology, and engineering design were integrated as instructional strategies. Surveys were conducted to measure teacher self-efficacy and outcome expectancy. Student STEM attitudes (self-efficacy and expectancy-value beliefs), 21st century skills, STEM career awareness, and STEM knowledge achievement …

Impact Of Squeezing On The Microstructure Of Thermal Interface Materials, R. Kantharaj, C. Wassgren, A. Morris, A. M. Marconnet

CTRC Research Publications

No abstract provided.

A Comparison Of The Localized Aviation Mos Program (Lamp) And Terminal Aerodrome Forecast (Taf) Accuracy For General Aviation, Douglas D. Boyd, Thomas A. Guinn

Journal of Aviation Technology and Engineering

Background. For general aviation (GA) pilots, operations in instrument meteorological conditions (IMC) carry an elevated risk of a fatal accident. As to whether a general aviation flight can be safely undertaken, aerodrome-specific forecasts (TAF, LAMP) provide guidance. Although LAMP forecasts are more common for GA-frequented aerodromes, nevertheless, the FAA recommends that for such aerodromes (and for which a TAF is not issued) the airman uses the TAF generated for the geographically closest airport for pre-flight weather evaluation. Herein, for non-TAF-issuing airports, the LAMP (sLAMP) predictive accuracy for visual (VFR) and instrument (IFR) flight rules flight category was determined.

Method. sLAMP …

A Review On Virtual Reality Skill Training Applications, Biao Xie, Huimin Liu, Rawan Alghofaili, Yongqi Zhang, Yeling Jiang, Flavio Destri Lobo, Changyang Li, Wanwan Li, Haikun Huang, Mesut Akdere, Christos Mousas, Lap-Fai Yu

Purdue University Libraries Open Access Publishing Fund

This study aimed to discuss the research efforts in developing virtual reality (VR) technology for different training applications. To begin with, we describe how VR training experiences are typically created and delivered using the current software and hardware. We then discuss the challenges and solutions of applying VR training to different application domains, such as first responder training, medical training, military training, workforce training, and education. Furthermore, we discuss the common assessment tests and evaluation methods used to validate VR training effectiveness. We conclude the article by discussing possible future directions to leverage VR technology advances for developing novel training …

Characterizing Students’ Engineering Design Strategies Using Energy3d, Jasmine Singh, Viranga Perera, Alejandra Magana, Brittany Newell

Discovery Undergraduate Interdisciplinary Research Internship

The goals of this study are to characterize design actions that students performed when solving a design challenge, and to create a machine learning model to help future students make better engineering design choices. We analyze data from an introductory engineering course where students used Energy3D, an open source computer-aided design software, to design a zero-energy home (i.e. a home that consumes no net energy over a period of a year). Student design actions within the software were recorded into text files. Using a sample of over 300 students, we first identify patterns in the data to assess how students …

A Deep Reinforcement Learning-Based Dynamic Computational Offloading Method For Cloud Robotics, Manoj Penmetcha, Byung-Cheol Min

Purdue University Libraries Open Access Publishing Fund

Robots come with a variety of computing capabilities, and running computationally-intense applications on robots is sometimes challenging on account of limited onboard computing, storage, and power capabilities. Meanwhile, cloud computing provides on-demand computing capabilities, and thus combining robots with cloud computing can overcome the resource constraints robots face. The key to effectively offloading tasks is an application solution that does not underutilize the robot's own computational capabilities and makes decisions based on crucial cost parameters such as latency and CPU availability. In this paper, we formulate the application offloading problem as a Markovian decision process and propose a deep reinforcement …

Changing The Process In Educational Field And Air Navigation Through Advances In Hologram Technology, Camilo Fernandez Sr.

Journal of Aviation Technology and Engineering

The objective of this piece is to propose reasons that change the way air traffic controllers and others learn and work in air navigation, but also how they can improve workloads, due to the implementation of holographic radar. This research also aims to describe how this could reduce the cognitive load of an operator, thanks to the improvement of visual perspective and capacity of analysis, in order to more easily control an aircraft.

Seeing that the visual facilitation is well known, radar is able to represent in three dimensions and in detail that which could not previously be perceived. This …

You Want Me To Teach Engineering? Impacts Of Recurring Experiences On K-12 Teachers’ Engineering Design Self-Efficacy, Familiarity With Engineering, And Confidence To Teach With Design-Based Learning Pedagogy, Shaunna Smith, Kimberly Talley, Araceli Ortiz, Vedaraman Sriraman

Journal of Pre-College Engineering Education Research (J-PEER)

This paper reports on findings from a group of ten teachers who were enrolled in a semester-long, graduate-level educational technology course that used design-based learning to explore the integration of making and the engineering design process into a variety of K-12 educational contexts. Using convergent mixed methods, this study examines how the course impacted teachers’ familiarity and confidence in teaching the engineering design process, as viewed through their pre- and post-semester engineering design self-efficacy scores and their weekly reflective journal entries. These measures are important factors for developing teacher experience and confidence in integrating engineering and design-based learning strategies within …

Notes On The Circulation Of Epistemic Images, Nina Samuel

Artl@s Bulletin

Three cases of image circulation in the sciences, two from complex dynamics and one from microscopy, are discussed. The article deals with failed circulations, suspected errors, interdisciplinary communication, notebooks of scientists, the role of media shifts, mathematics and materiality, human perception, pictorial norms and conventions. It analyses how images circulate through different thought collectives and visual cultures. All three examples show different strategies of how images that break with visual traditions have been reintegrated into epistemic circulations and become “boundary objects” that are both robust and flexible.

Travelling Images In The Global Context: A Case Study Of The Short-Lived 18th Century Akita Ranga Painting School In Japan, Kuniko Abe

Artl@s Bulletin

By exploring early available travelling Western illustrations, image sources for the Akita Ranga painters in eighteenth century Japan, this article attempts to show how they developed, merging Japanese traditional Kano school aesthetics, new realistic Chinese trends for still-life images, and Western type illusionism, using Japanese traditional pictorial materials. The Akita Ranga school’s inventive compositional framework is the consequence of interaction with European models traced back to the famous Vesalius anatomy images with landscape, finally reaching Europe via Ukiyo-e prints, forming a full circle of the migration of images.

Family Depression Profiles Among Adolescents And Their Parents: A Group-Based Multi-Trajectory Modeling, Xiang Zhou, Xiaoning Sun

Department of Educational Studies Faculty Publications

Early onset of depression predicts unfavorable psychosocial and health outcomes, and depression often co-occurs for children and their parents, yet family profiles of depression trajectories are not fully examined. This population-based longitudinal prospective cohort study included 2,111 families drawn from the Chinese Family Panel Study (CFPS) with biannual assessments from 2010 to 2018. Group-based multi-trajectory modeling was used to identify depression trajectories of children, fathers, and mothers. Six distinct profiles of depression symptoms were identified. Based upon multi-trajectory findings of family depression profiles, when adolescents are at risk for depression, there is likely at least one parent concurrently at risk …

Why Abdominal Aortic Aneurysms Rupture: Predicting Pressure And Diameter At Failure, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

Objective: To perform a first-principles biomechanical analysis of the process of aortic aneurysm rupture, based upon the balance of expanding forces from blood pressure and reactive forces from wall elasticity, and to explore new methods for prediction of rupture risk. Methods: A mathematical model is created to describe the forces acting on a localized, weak patch of aneurysm wall during the cardiac cycle. A method to obtain patient-specific model parameters non-invasively, including incremental Young’s modulus, from cine ultrasonic or magnetic resonance images is proposed. Results: Pre-rupture integrity of an aneurysm is maintained by the balance between the expanding forces and …

Characteristics Related To Parent-Child Literacy And Numeracy Practices In Preschool, Amy R. Napoli, Irem Korucu, Joyce Lin, Sara A. Schmitt, David J. Purpura

Purdue Center for Early Learning Faculty and Staff Publications

Despite evidence suggesting that home literacy and numeracy environments are related to children’s school readiness skills, little research has examined the child and family characteristics that relate to the home literacy and numeracy environments within the same sample. These factors are important to investigate in order to determine what may foster or prevent parent-child engagement. The primary purpose of this study was to examine the shared and unique parent-reported child and parent variables that are related to the frequency of parent-child literacy and numeracy practices. The 199 preschoolers included in the study ranged in age from 3.00 to 5.17°years ( …

Reader’S Roundup: Monographic Musings & Reference Reviews, Corey Seeman

Against the Grain

No abstract provided.

Collecting To The Core — Writing In Mathematics, Kristine K. Fowler, Anne Doherty

Against the Grain

No abstract provided.