Precision Agriculture

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Project Description
This ongoing project aims to explore the use of Web GIS in precision agriculture. We used a suite of open source tools to develop a prototype open-source Web GIS to manage, process, and disseminate spatial information to each farmer. In the next step, we will leverage some fine-grain phenology model to produce some data products and disseminate the results to farmers using Web GIS.

My Role: software architect/developer
I worked as a software architect for this project.

Tools
Python, GeoDjango, GeoServer, PostgreSQL/PostGIS, HTML, JavaScript, CSS

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Wildfire Evacuation Zoning

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Project Description
This ongoing project aims to study how evacuation zones are delineated in wildfires.

My Role: GIS Analyst/Developer
I have been working with different county GIS agencies to collect relevant evacuation data for my research. I am developing a suite of open source software tools to manage, process, and analyze the wildfire evacuation zone data I have collected.

Tools
Python, R, PostgreSQL/PostGIS, QGIS

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Telecoupling

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Project Description
This project is characterized by using the developed telecoupling framework to study global food security and land use.

My Role: Systems Modeler/Software Engineer
I worked as a systems modeler/softare engineer for this project.

Tools
Java, R, HTML, JavaScript, CSS, LeafLet, GeoServer,PostgreSQL/PostGIS, ArcGIS

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HashtagHealth

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Project Description
HashtagHealth was a project funded by the National Institute of Health (NIH) as a Mentored Research Career Development Award for Dr. Quynh Nguyen at the University of Maryland. This project proposes to design and develop a new resource, HashtagHealth, that addresses both the dearth of neighborhood data and offers novel characterizations of neighborhoods. We will build the data algorithms and infrastructure to harness relatively untapped, cost efficient, and pervasive social media data to develop neighborhood indicators such as food themes, healthiness of food mentions, frequency of exercise/recreation mentions, metabolic intensity of physical activities, and happiness levels.

My Role: GIS Developer/Specialist
I worked as the GIS developer/specialist for this project. My responsibilities include spatial data processing, geovisualization, and web portal development.Specifically, I compiled and merged census tract and zip code zone data for all the states in the U.S. and spatially joined millions of geotagged tweets with the census tracts and zipcode zones they fall within using Python. I mapped out the analysis results (happiness scores, food and exercise mentions) at census tract and zipcode zone levels for three counties and the whole nation. Moreover, I built a web portal that publishes relevant results using WebGIS.

Tools
Python, HTML, JavaScript, CSS, LeafLet, GeoServer,PostgreSQL/PostGIS, ArcGIS

Relevant Publications
Meng, H.-W., Kath, S., Li, D., & Nguyen, Q. C. (2017). "National substance use patterns on Twitter". PLOS ONE, 12(11), e0187691. doi:10.1371/journal.pone.0187691
Nguyen, Q., McCullough, M., Meng, H., Debjyoti, P., Li, D., et al. (2017). "Geotagged U.S. Tweets (2015-2016) as Predictors of County-Level Health Outcomes". American Journal of Public Health doi: 10.2105/AJPH.2017.303993
Nguyen, Q., Meng, H., Li, D.,Kath, S., et al. (2017). "Social media indicators of the food environment and state health outcomes". Public Health, 148, 120-128. doi:10.1016/j.puhe.2017.03.013
Nguyen, Q., Li, D., Meng, H., Kath, S., Nsoesie, E., Wen, M., & Li, F. (2016). Building a national neighborhood dataset from geotagged Twitter data for indicators of happiness, diet, and physical activity. JMIR Public Health & Surveillance. doi:10.2196/publichealth.5869
Nguyen, Q. C., Kath, S., Meng, H.-W., Li, D., Smith, K. R., VanDerslice, J. A., Wen, M., & Li, F. (2016). Leveraging geotagged Twitter data to examine neighborhood happiness, diet, and physical activity. Applied Geography, 73, 77-88. doi: http://dx.doi.org/10.1016/j.apgeog.2016.06.003

Source Code
https://github.com/hashtaghealth

Project Website
https://hashtaghealth.github.io

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Mobile Health

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Project Description
This is a project funded by the National Institute of Health (NIH), and the principal investigator is Dr. Neng Wan in the Department of Geography at the University of Utah. This project proposes to design and develop a software system that can be used to collect health-related data using smartphones.

My Role: Mobile Developer/Data Scientist
I worked as an Android developer/data scientist for this project. Specifically, I developed an Android app that collects bluetooth, GPS, and accelerometer data to study the relationship between human mobility and people's well-being. Moreover, I used machine learning to classify activity based on the collected acceleromter data.

Tools
Android, Java, Python, Matlab, R, Git

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Protective Action Triggers

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Project Description
"Protective Action Triggers" is a project funded by the National Science Foundation (NSF), and the principal investigators are Drs. Tom Cova and Phil Dennison in the Department of Geography at the University of Utah. This project aims to improve our understanding of wildfire evacuation timing and warnings by using triggers.

My Role: GIS Modeler/Software Engineer
I worked as a GIS Modeler/Software Engineer for this project. First, I developed a model that uses trigger modeling to stage household-level wildfire evacuation warnings. Second, I constructed a model that can identify prominent geographic features near the wildfire evacuation trigger buffer boundary as trigger points using reverse geocoding and viewshed analysis. Lastly, I coupled wildfire simulation, trigger modeling, and traffic simulation to explore the dynamics behind wildfire evacuation timing.

Tools
C/C++, Python, Java, R, FlamMap, FarSite, ArcGIS

Publications

Li, D., Cova, T.J., & Dennison, P.E. "Setting Wildfire Evacuation Triggers by Coupling Fire and Traffic Simulation Models: A Spatiotemporal GIS Approach". Fire Technology. doi: https://doi.org/10.1007/s10694-018-0771-6 (In press)

Li, D., Cova, T.J., & Dennison, P.E. (2017). “Using reverse geocoding to identify prominent wildfire evacuation trigger points”. Applied Geography, 87, 14-27.doi: 10.1016/j.apgeog.2017.05.008

Cova, T.J., Dennison, P.E., Li, D, Siebeneck, L.K., Drews, F.A., & Lindell, M.K. (2017). "Warning triggers in environmental hazards: who should be warned to do what and when?" Risk Analysis. doi: 10.1111/risa.12651

Li, D., Cova, T.J., & Dennison, P.E. (2015). "A household-level approach to staging wildfire evacuation warnings using trigger modeling”. Computers, Environment, and Urban Systems, 54, 56–67.

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Open Source Software

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Project Description
This ongoing project is related to the NSF "Protective Action Triggers" project and is characterized by open source software development. Specifically, this project aims to design and develop a suite of open source software tools for wildfire evacuation applications.

My Role: Software Engineer
I have been working as the primary developer for this project.I have developed an open source software tool for wildfire evacuation trigger modeling using fireLib. My current work focuses on developing an open-source GRASS GIS tool for wildfire evacuation trigger modeling.

Tools
C/C++, Qt, fireLib, GRASS GIS

Source Code
https://github.com/lidapeng/Triggers

Publications

Li, D., Cova, T.J., & Dennison, P.E. “An open-source software system for setting wildfire evacuation triggers". (2015). 1st ACM SIGSPATIAL International Workshop on the Use of GIS in Emergency Management.doi:10.1145/2835596.2835600

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GeoUTA

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Project Description
GeoUTA was an android app that is intended to make it more convenient for those who need to catch the bus in Utah. Traditionally, people will use bus schedules to catch a bus. All the Utah Transit Authority (UTA) buses/trains have GPS receivers installed on them and their locations could be retrieved and recorded into the UTA bus tracking database simultaneously.

My Role: Android Developer
I worked as the primary developer for this project.

Tools
Java, Android, Google Map API

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