articles about forecasting and the Covid-19 pandemic

Here is what I’ve been reading about forecasting and COVID-19:

  1. Nature has a nice article on forecasting: The simulations driving the world’s response to COVID-19
  2. The Kaiser Family Foundation has a nice introduction to forecasting models for epidemiology: COVID-19 Models: Can They Tell Us What We Want to Know?
  3. Fotios Petropoulos and Spyros Makridakis published an article in PLOS ONE entitled Forecasting the novel coronavirus COVID-19
  4. The mathematics of predicting the course of the coronavirus from Wired
  5. Why it’s so hard to see into the future of Covid-19: human behavior from Vox
  6. FiveThirtyEight on Why it’s so freaking hard to make a good COVID-19 model
  7. Finally, science writer Ed Yong has written a few articles about COVID-19 for The Atlantic that focus on the future, including How the pandemic will end based on what we know from other related viruses, Our Pandemic Summer, and Why the Coronavirus is so Confusing 

Related posts:

articles about supply chains and Covid-19

Here is what I’ve been reading about supply chains in the COVID19 era:

  1. Vox on food and meat supply chains
  2. Why there are toilet paper shortages
  3. The Society for Risk Analysis recorded a webinar called “COVID Conversations on Risk” (Ep 3) about food security
  4. The Washington Post on why meat supply chains are vulnerable to Covid-19 outbreaks: they are massive facilities with thousands of workers in close proximity 
  5. Why you can expect shortages of pharmeceuticals but not toilet paper (nice job, Anna Nagurney)
  6. On personal protective equipment (PPE) supply chains
    1. Read about the origins of the Strategic National Stockpile
    2. CDC guidance for optimizing supply chains
    3. The Washington Post reports on a factory that produces a chemical used in PPE
  7. The modern supply chain is snapping from The Atlantic. Note this came out a month ago.
  8. We need a stress test for critical supply chains (nice job David and Edith Simchi-Levi)
  9. And finally, Belgians are urged to eat French fries at least twice a week as changes in consumption during the pandemic lead to a massive potato surplus


Related posts:

how to organize your Tupperware cabinet

Rumor has it that many people are taking advantage of the extra time at home during the COVID-19 pandemic stay at home orders to organize their food container/Tupperware cabinet. It’s such a popular pandemic activity that The Onion published a satirical article about it.

My food container cabinet is always organized and optimized. I took a picture below. The secret to organizing my cabinet is to formulate it as an integer programming model and then solving it to optimality. I have my kids resolve the integer programming model every time they unload the dishwasher and put the dishes away.

I’m kidding.

I organize my cabinet with a heuristic. I nest my food containers in a few stacks that fit in the cabinets. Once I organize the cabinet, there are a few food containers that do not nest with the nicely organized stacks. The most important part of this process is to remove the few food containers that do not nest with the other containers (see the bottom picture). A few problematic food containers can lead to chaos and disorder. I do not throw these out. Instead, I use them to store items throughout my house (e.g., in my toiletries cabinet and tool cabinet). 

I have not purchased food containers in awhile. When I do, I purchase them based on their nestedness properties.

How do you organize your food container cabinet?

An organized and optimized food container cabinet

The key is to remove the pieces that don’t nest.

Related posts:

on vampires, exponential population growth, and scientific literacy

Eleven years I wrote a tongue-in-cheek blog post about vampires and stochastic processes. I was inspired by my course material about Markov chains and branching processes, which has application to the spread of infectious disease, to the vampire population dynamics in the Twilight series and other teenage vampire stories that were very popular at the time.

I have a great deal of skepticism about vampires.

Here’s my problem with vampires. I have a hard time believing that there would be just a few vampires out there and that the existence of vampires would be such a well-kept secret. After all, they reproduce rather easily (a single vampire could create thousands of offspring, whereas there are limits to human reproduction) and vampires don’t die easily. If there were vampires, they would almost certainly outnumber humans (but then vampires would run out of food).

This argument becomes even more overwhelming if you model a vampire population as a branching process or birth-death process and assume that each vampire in the population has probability Pj of producing j offspring (with j=0,1,2,… ). The vampire population would either explode or die out, depending on the expected number of offspring per vampire. But if you take into account the fact that vampires live many, many generations (they’re virtually immortal) and may create thousands of offspring, the population explodes (if you assume that each vampire creates at least one vampire, on average, before it dies). With those numbers, vampires would not be living under the radar–they would be everywhere!

I have yet to see a vampire movie that implicitly assumes that there is a reasonable model for vampire population dynamics (using a stochastic process framework or something else). And frankly, I’m pretty disappointed. Until I am offered a reasonable explanation for why there aren’t more vampires, I won’t be able to jump on the vampire bandwagon.

This issue had been bothering me since I first saw The Lost Boys, long before I knew about Markov chains. I enjoyed The Lost Boys, but I did not enjoy it’s inability to acknowledge exponential vampire population growth. Markov chains later helped me understand why my skepticism was valid.

The post went viral. Life was interesting for awhile. Twilight fans hated me.

My blog post was never intended to be taken seriously. It was not a serious critique of vampires, because vampires aren’t real.

Once in awhile, I google myself to see what turns up. Over the years, I have found that several vampire fan news sites and blogs that existed at the time (teenage vampire stories were very popular at the time) picked up my blog post and wrote serious articles about it.

Some of the concerning coverage of my post was on vampire fan websites that no longer exist online. A decade ago I remember discovering a vampire fan website for teenage girls with a domain that may have been that made a serious two minute “vampire news” video about my “research” in vampire population dynamics that supposedly proved that vampires could not exist. The host discussed my blog post like it was real research. I was disheartened by this. I would like to engage teenage girls about operations research and analytics but without the vampires. It’s only fun if it gets people more engaged with real research, science, and engineering.

A positive example is the one entitled “Vampire Ecology: Twilight vs. Buffy” on a science blog that argues that vampires could exist by linking to another tongue-in-cheek paper that takes human predation on vampires into consideration as a form of vampire population control. It doesn’t seem to take my post too seriously (phew).

I have given a lot of though to increasing scientific literacy in the general public for the last decade. The far-too-serious coverage of my silly vampire post did not dissuade me from engaging the public about my research. Instead, it encouraged me to be more intentional with how I communicate scientific principles to the public and motivated me to discuss real scientific issues with the general public as much as I can. I have blogged about some of my public talks and have appeared in the media many times. I have found that a lot of people are receptive to science and engineering research, especially if it seems relevant to their lives. I try to stick to applications of operations research, analytics, and industrial engineering in the public sector.

I’ve been encouraged by the discussion of real scientific principles during the COVID-19 pandemic. It’s been a positive side effect of a serious pandemic. I hope the public’s interest in science continues.




Auf Wiedersehen Wisconsin, Hallo Deutschland!

This post is about my first month getting situated on my sabbatical in Germany. The second month was consumed by the spread of COVID-19, and I had to return to the U.S. in less than two months. This post should be entitled “Auf Wiedersehen Deutschland, Hallo Wisconsin!” but I will save the COVID-19 related experiences for another post.

My two few days was solely dedicated to moving into my apartment. In my last post, I wrote about how I preemptively placed an order for IKEA furniture a week before leaving the US so that the order would be delivered right after we arrived. This plan worked perfectly. Additionally, it felt satisfying to put together our furniture and get settled into our new home. We also made a couple of trips to grocery stores to stock up on necessary food and water. We brought a few tote bags to carry our groceries home. Luckily, we have two discount grocery stores within half a mile of our apartment. I highly recommend taking children to a grocery store and letting them pick out a bunch of new food to try, even familiar favorites like Oreos. We made an effort to try new things up front, and that helped us discover a few favorite new foods early on. Everything was new, and this was more difficult for the children than it was for me, but we enjoyed sampling the many types of pastries, cakes, and chocolates available in Germany.

Eventually we picked up a few things to make life in Germany easier: a water cooker for boiling water, tupperware, a hair dryer and curling iron, a big European drying rack, dishes and kitchenware, notebooks, and a mop.

Thanks to the documentation from the Department of State, who manages the Fulbright, and the RWTH Aachen Welcome Center, I printed out all the documents we needed. I had a huge binder full of documents. But the paperwork was overwhelming. The children were almost entirely shielded from the bureaucracy, and I was relieved that the stress of moving to Germany fell on my shoulders. Bureaucratic tasks for adjusting to German life included:

  • Resident registration and related tasks
  • Immigration
  • Cultural integration / education of the children and related accounts (all day care, bus tickets)
  • University registration as a visiting professor
  • Public transportation and train accounts
  • Bank account
  • Cell phone SIM card activation

Registering with the citizen’s office in Germany was a pain. This was something everyone must do within two weeks of when they move to a new apartment, not just newcomers to Germany. Appointments can be made but there is a one month wait, so the only way to register is to arrive at the office at 7:30am with the children, pull a ticket (like at the DMV in the US), and wait. On our first try, the central computer for our region of Germany used to register everyone in the region went down, and we had to come back the next day first thing in the morning.

After registering our address, we applied for a residence permit with the immigration office. Again, the children came with me. We could complete this step at the university, and it was very easy. We had all of our papers ready and brought passport photos that we printed out ahead of time at a drugstore in the US. The photos needed in Germany are basically the same but cut to a smaller size. The person working in the office cut our photos to a smaller size, so we did not have to come back with new photos.

I needed a bank account in Germany for my Fulbright. It was easy to set up an account with the N26 bank.

Once the children were in school, paperwork was never-ending. One week I hypothesized that German bureaucracy is like a marathon because I had hit the “wall” the previous week. Another time it felt like a series of nesting dolls, with each task leading to another smaller sub-task that I could not see earlier. I thought I had checked something off my list (registering the children for a bus pass), but then I had to take the form to a city office. That didn’t end the registration process. Instead, I was told to wait for something to arrive in the mail, fill it out, and return it. Finally, it seemed like an Escape Room. You keep think you’re getting close to figuring out how to complete the paperwork, but then there is another puzzle (or puzzling form) to figure out. I did better once I accepted that I needed to devote a few hours per week to paperwork. Sadly, we had to return to the US just after I figured everything out and was ready to settle into my research routine.

Getting used to public transportation was another step in the adjustment process. I find it easy to navigate with public transportation. I used two apps: google maps and the AVV app to find real-time bus route information in Aachen.

News media

I discovered some news sources. I subscribed to the Local (expat friendly German news in English) and Deutsche Welle. I listened to the weekly podcast/radio program “Inside Europe” from the Deutsche Welle. “Slow German” was great for practicing German. Paying for a subscription to the Local was well worth it, especially to keep on track of COVID-19 news.

I was glad I had these items with me

  • Buffs/multi-functional headwear The knock-off versions are about $1 apiece and have a lot of uses.
  • A deck of cards and/or Uno cards.
  • Travel yoga mat.
  • Smartphone apps: google maps with downloaded maps of places we visited, google translate, and public transportation apps
  • First aid kit: thermometer, band-aids, Tylenol, children’s Tylenol, children’s Advil, Neosporin, Aquaphor, and Hydrocortisone. I used all of these items, and each time I was relieved I didn’t have to make a special trip to the store. I’m proud to say I had no mishaps with the electric bread slicer in my apartment.

First days were fun too

The first few days were full of fun discoveries. We discovered the endless supply of chocolate at area stores. We also purchased an annual zoo pass for the zoo that was a quarter mile walk from our apartment. We visited 3-5 times per week, usually for a long stroll through the zoo by each of our favorite animals.

In my next sabbatical post, I will blog about how I got started with sabbatical planning.

Read more blog posts about my 2020 sabbatical here and see my tweets using the “PunkRockORinGermany” hashtag on twitter. I had to end my trip to Germany early due to the COVID-19 outbreak.


COVID-19 is a pandemic that requires systems thinking and solutions

I was on the INFORMS Resoundingly Human to talk about COVID-19 and first responders. You can listen here:

In the podcast, I discuss supply chains, rationing resources, and disaster planning, and I note how everything old becomes new again. For example, the US is not experiencing its first N95 mask shortage. Systems concepts are important for understanding how to prepare for and respond to a pandemic.

In this post, I want to dig deeper into systems concepts. I wrote a quick primer on systems thinking and explain why systems concepts are important for understanding the COVID-19 pandemic.

What is a system?

A system is a set of things—people, vehicles, basketball teams, hospital beds, or whatever—interconnected in such a way that they produce their own pattern of behavior over time.

Here are three examples:

(1) A car is just a vehicle. A collection of cars can be a traffic jam.

(2) A single ventilator can be used to treat a patient. A hospital’s collection of beds and ventilators are available for treating patients. When a surge of patients require these resources, they may have to wait and queue for these limited resources.

(3) An N95 mask protects first responders from infectious disease when they treat patients. A supply chain of personal protective equipment (PPE) can have delays and shortages, leading to first responders not having the N95 masks they need at any given moment.

How is systems engineering relevant to COVID-19?

COVID-19 is absolutely a medical challenge. It is also a systems challenge that require systems thinking and systems solutions. In systems, decisions are not made in isolation, but rather, decisions are interrelated.

My discipline is operations research: the science of making decisions using advanced analytical methods. Systems require a series of decisions to operate effectively with or without patient surges in a pandemic. Operations research provides the analytical tools required to design and operate systems more effectively and efficiently.

In systems there are many trade-offs and complicated interactions. Here are examples of how systems engineering is important now:

(1) If a first responder does not have adequate personal protective equipment (PPE) such as latex gloves and N95 masks, they are at higher risk from acquiring COVID-19. If they do, they will not be able to treat patients in the coming months, thereby reducing the number of first responders (a critical resource) in the future. This informs how responders should treat patients and ration resources now.

(2) Surges in COVID-19 cases may lead to more patients requiring ventilators than are available in hospitals. This could lead to rationing and painful choices that would not be considered without a patient surge.

Systems concepts will continue to be important in the future. Here is a third example:

(3) One person who gets a vaccine has immunity. If enough people receive vaccines or have immunity from previously having had the disease, we can achieve herd immunity and eliminate person-to-person transmission of the disease even among those who do not have immunity. With herd immunity, the benefits are greater than the sum of its parts.

What can systems thinking tell us about the fatality rate for COVID-19?

It depends. We know that it depends on age, gender, and co-morbidities. The fatality rate is not an exogenously given number, but rather it is a function of the resources available for treating patients, which is endogenous to the system. The fatality rate for COVID-19 is a systems concept. If the number of infected individuals is low enough so that hospitals can handle the surge and give every patient the treatment they require, the fatality rate will be lower (relatively speaking. In absolute terms it will still be too high). The fatality rate will be a lot higher if hospitals are over capacity and have to ration beds and ventilators.

How are my personal decisions related to healthcare systems in the COVID-19 pandemic?

The resources in our healthcare system are being stretched to the limit. The resources include personnel (physicians, nurses, first responders), hospital beds, ventilators, and personal protective equipment. When there are not enough resources to give every COVID-19 patient the best treatment they require, physicians will have to ration resources and make tough choices. Our efforts to delay the second wave as long as possible and to reduce the number of people who require medical treatment will save lives. Flattening the curve is a systems concept aimed at reducing painful tradeoffs and complicated interactions.

How can we prevent the next wave?

Preventing the next wave of any infectious disease is a numbers game. I do not know how to practice medicine but I know how to crunch numbers. The key is to lower the overall transmission rate. The best way to lower the transmission rate varies according to the disease, but there are some basic principles for preventing a disease outbreak from becoming another wave of a pandemic. Best practices include better hygiene practices such as washing your hands and your mobile phones with soap and water, and covering your cough. Limiting the number of people you come in contact with reduces the opportunities for transmission. All those trips to the store to buy extra toilet paper increase one’s chance of contracting COVID-19.

What can we do to prepare for a second wave?

A second wave in a prolonged pandemic is not going to be easy for many of us. I use mathematical models and analytics in my research, and I find them to be useful in my everyday life. My research tells me that I make better decisions with better information and that I should use limited resources wisely. When I think about what it means to apply these principles to my decisions in a pandemic, I realized I can achieve both of these goals by gathering up to date information and following instructions from official, trusted sources such as local and state governments, local police and emergency medical service departments, and the Centers for Disease Control and Prevention. I plan to use the official sources to limit what I think about, worry about, and do in any upcoming waves of the pandemic. We are all inundated with conflicting information and advice from many sources, and it is taking its toll and potentially leading us to make unsafe choices such as making repeated trips to grocery stores to stockpile items we do not need.


Related posts:

Travel Bans Can’t Stop this Pandemic

My op-ed entitled “Travel bans can’t stop this pandemic” was published in The Hill. You can read it here.


emergency response during mass casualty incidents

Today’s blog post about my research on mass casualty events and emergency response given that COVID-19 has been declared a pandemic by the World Health Organization (WHO). I have four papers in the area that are relevant in the area of emergency medical services (EMS) during mass casualty incidents.

A mass casualty incident (MCI) is an event in which the demand for service overwhelms local resources. Since fire and EMS departments operate at the local level, they can be overwhelmed quite easily. Anything from a multiple vehicle accident to a weather disaster to a hospital evacuation can be considered an MCI. Fire and EMS departments have “mutual aid” agreements with neighboring departments to address the more routine of these incidents and have “Standard Operating Procedures” for a range of more severe incidents. However, switching between such policies in practice is not simple. Moreover, not all mass casualty incidents are the same. Responding to calls for service during a hurricane is different than during a pandemic. In the latter, paramedics and emergency medical technicians can become sick and should stop treating patients, leading to fewer resources for responding to patients that require service. Additionally, we would expect less road congestion and wind during pandemics than in a hurricane evacuation. However, both cases may see a surge of low-acuity patients who request service.

My research focuses on emergency response during MCIs lifts limiting assumptions made by papers in the literature, which often assume that there are enough resources available all the time (which is not a reasonable assumption during MCIs). Here is a summary of four of my papers that have addressed MCIs.

Dubois, E. Albert, L.A. 2020. Dispatching Policies During Prolonged Mass Casualty Incidents. Technical report, University of Wisconsin-Madison.

The newest paper is available as a technical report and is most relevant to COVID-19. It focuses on a large surge of patients that overwhelmed EMS resources. Here, we lift the assumption that a patient’s priority is a fixed input. Instead, we consider patients whose conditions deteriorate over time as they wait for service.  We consider how to assign two types of ambulances to patients, advanced and basic life support. We study how to dispatch ambulances during MCIs while allowing ambulances to idle while less emergent patients are queued. This is similar to keeping a reserve stock of advanced life support ambulances (see the last paper listed in this post). The inherent trade-off is that when low-priority patients are asked to wait for service, they can become high-priority patients. When high-priority patients are asked to wait for service, they can become critical or die. Our solution method is to find dynamic response policies to match two types of ambulances with these three types of patients.  We observe that, under the optimal policies, advanced life support ambulances often remain idle when less emergent patients are queued to provide quicker service to future more emergent patients. It is counter-intuitive to not use all resources all the time during an MCI. However, keeping some resources in reserve ensures that there are resources available at the time the most critical patients need them.

McLay, L.A., Brooks, J.P., Boone, E.L., 2012. Analyzing the Volume and Nature of Emergency Medical Calls during Severe Weather Events using Regression Methodologies. Socio-Economic Planning Sciences 46, 55 – 66.

The second paper seeks to characterize the volume and characteristics of EMS and fire calls for service. It was motivated by the need to deliver routine emergency service during weather emergencies and disasters. What typically happens during emergencies is that there are more calls for service, most of which are low priority calls. Triage becomes more important in these situations, because the most severe calls for service can be drowned out by so many low-priority requests. However, call surges are not the only stress on fire and EMS departments. Road congestion and slow travel times mean that each call takes more time to serve, which can further stress limited resources. As a result, it becomes important to triage calls and assign appropriate resources.

Kunkel, A., McLay, L.A. 2013. Determining minimum staffing levels during snowstorms using an integrated simulation, regression, and reliability model. Health Care Management Science 16(1), 14 – 26.

The third paper studies staffing levels during a blizzard, where a surge of calls can temporarily overwhelm resources that are available. Additional staff are usually scheduled during emergencies when call volumes increase. We specifically focus on snow events, and the results have insight into other situations. To determine staffing levels that depend on weather, we propose a data-driven model that uses a discrete event simulation of a reliability model to identify minimum staffing levels that provide timely patient care,with regression used to provide the input parameters. We consider different response options, including asking low priority patients to wait for service, and we take into account that service providers often work faster when systems are congested. The latter issue of allowing adaptive service rates is important, since it makes the model more realistic by limiting the assumption that service rates are constant. A key observation is that when it is snowing, intrinsic system adaptation with respect to service rates has similar effects on system reliability as having one additional ambulance.

Yoon, S., Albert, L. 2018. An Expected Coverage Model with a Cutoff Priority Queue. Health Care Management Science 21(4), 517 – 533.

The final paper examines how to locate and dispatch ambulances when resources can be temporarily overwhelmed. In this paper, there are prioritized calls for service in a congested system, but the system is not completely overwhelmed by an MCI such as a hospital evacuation. Typically, models in the literature implicitly assume that there are always enough resources to respond immediately to all calls for service that are received. This is not a good assumption when there is an MCI. As a result, we need new models and analyses to provide insights into how to allocate resources when there is congestion and many service providers are busy treating patients.

We formulate new models to characterize policies when ambulances are held in reserve for high priority calls. When the system is so congested that it hits the “reserve” stock of ambulances, low priority patients are either diverted to neighboring EMS systems through mutual aid or added to a queue and responded to when the congestion has reduced. Interestingly, we find that by adopting such an approach for sending (and not sending) ambulances to patients, this affects where we might want to locate ambulances at stations.




Angst: Preparing for an overseas sabbatical

Preparing for a six month sabbatical overseas was daunting. My sabbatical takes me to Aachen, Germany from January until July, a span of six months. In addition, I had to prepare for my daughters for this trip. This blog post is about how I moved with my family to a new country, focusing on month leading up to the sabbatical once I knew where and when I was going. A post about the longer-term planning will come arrive.


Thanks to Sara Zaske (author of Achtung Baby, which I highly recommend), I knew I should print out and prepare folders full of important copies of documents to navigate German bureaucracy. This was the smartest way I prepared. Some of the documents I packed include various forms and instructions from the Fulbright Commission.

  • Copies of Fulbright documents, including the letter indicating I could work in Germany for longer than 90 days
  • Copies of the invitation letter from RWTH Aachen
  • Copies of health insurance (required for living in Germany)
  • Birth certificates (with extra copies)
  • Copies of passports
  • Copies of report cards (for my daughters)
  • Copies of all travel documents

Deciding what to pack

It became clear that I would need a lot of outfits for work, conferences, relaxation, and running. I also needed shoes for all these activities. I used the Set Cover problem to decide what clothes and shoes pack that could “cover” most of my outfits across these activities I would take part in. It became immediately clear that my shoes and wardrobe would have to be compatible with the color black if I wanted to fit my clothing into one large suitcase. I had to pack shoes for many occasions, and I decided that my outfits should mostly go with a series black shoes (sandals, flats, pumps, booties, boots). Gray was a second choice for color compatibility. I left a pair of jeans at home because they did not go with enough outfits or shoe choices. My kids packed a few small games for us to play in Germany. It was nice to have some entertainment.

Preparing my devices (phone and iPad) for the sabbatical was one of the most important ways I prepared for the trip.

  • I downloaded a map of Aachen on google maps.
  • I downloaded the google translate app on all of my devices, and I downloaded German so I could translate when offline.
  • I downloaded the latest version of google voice on my phone so I would have access to a stable US phone number that could make phone calls and receive SMS texts.
  • I downloaded a few books on the Kindle for my children to read.
  • I created a WhatsApp account that I started using with folks in Germany.
  • Other apps included Deutsche Bahn, a conversion app (for distances, temperatures, etc.), and Aachen’s public transit app.
  • I forwarded all of my travel confirmations to Trip It.

I purchased and/or a few items that were extremely useful before my trip:

  • Outlet adapters with USB adapters (Six was about right for the four of us). We like the ones with USB ports.
  • I bought a discount Deutsche Bahn card (the Bahn 25) for discount rail tickets. I purchased a flexible, discount ticket for my trip from the Frankfurt airport to Aachen ahead of time.
  • I bought a new Amazon Kindle Fire for my kids to read books abroad, since English speaking books would be hard to find. We checked out copies of digital books from our library in Wisconsin, and we bought a few e-books as needed.
  • I bought a packable water-resistant, wind-proof Primaloft jacket from Lands End for a prior trip that was perfect for my sabbatical as an all-purpose coat in Aachen, where it has been cold, rainy, and windy.
  • A small wireless bluetooth speaker. It was nice to carry around a speaker and helped me stream podcasts and audiobooks while at home. But I could have lived without this.
  • A copy of Rick Steves Germany. I could not live without this.
  • Samsonite compression packing bags. I basically zip-locked my belongings in these large bags and squeezed the air out to pack more of my belongings into my suitcase more tightly. This was helpful for sweaters and other bulky items.

I packed a few extra tote bags and backpacks that could be laid flat in suitcases. These ended up being very useful, since we did not have a car and had to walk home while carrying our heavy grocery bags. I decided to purchase lotion, hair products, hand sanitizer, and other heavy toiletries in Germany to keep my bag lighter. This was a good decision, mostly because it was fun to shop for new items in Germany. I packed a few travel size shampoo and conditioner to tide me over. Toiletries and cleaning products are significantly cheaper in Germany. I also packed a few old towels, hot pads, sheets, fleece throws, and pillowcases to be able to use beds in the new apartment (and not make the return journey). In retrospect, I should have done some research on where to purchase thrifty towels and sheets near my flat. But it was nice having some immediate towels and hot pads to use. There are many discount stores in Germany, so it was extremely easy for us to buy what we needed in Aachen with very little effort. We bought all sorts of things at Aldi, including fleece sock liners, hoodies, sneakers (we quickly wore out the sneakers we brought due to so much walking), and even a coat when my daughter’s zipper broke. We are lucky that Germans like a bargain. There were several discount stores within half a mile of our flat.

COVID-19 broke out in Germany before I was able to stock up on disinfecting wipes and gel. That was unfortunate, but that was a fluke event that I could not anticipate. We are still able to wash our hands and use cleaning products. I will likely write a blog post just about COVID-19 at some point.

I decided to get a SIM card for my cell phone in Germany. My research indicated that Aldi Talk was the best plan in the country, but the registration process was difficult. I had to register for the SIM cards in Aldi with my passport, and the set up process took was confusing for me. It took me a few days to set up the SIM card, mostly because the PUK code did not work the first time I tried it, and I was confused on how to get my phone to recognize the new SIM card. It was a long time without a cell phone.

Preparing for life overseas.

I had to prepare to live overseas. I made a list and I started to think about changes months ahead of time. One of the challenges was to ensure that I could access all of my accounts that require two factor authentication (my university, google, dropbox, Paypal, Box, Amazon, others). I did not yet have a cell phone in Germany, so I changed the mobile phone number associated with my accounts to my google voice number. I signed up for as many email statements instead of mail statements for my bank, credit cards, insurance, and utilities. I unsubscribed from email lists for shopping in the US. I let my bank know I would be traveling. I made sure my credit cards and insurance accounts were set to auto-paid.

I suspended my car insurance for six months. I called to cancel various activities that my daughters were involved in (Irish dance, after school care, gymnastics).

Preparing my home for the move was easy, since my partner could not spend the entire sabbatical in Germany. He was able to look after the house and the cats aside from his planned trips to Germany to see us.

Preparing my children for overseas.

I had a plan for the children to take online classes while we were away. I was in contact with the children’s school teachers the year prior to moving. Fall parent teacher conferences in November was a good time to have a personal conversation with all teachers and sketch out a plan for the January transition. This made it easy to touch base to discuss follow up issues with teachers right before we left. I planned to fly to Germany the week after my oldest took her high school finals in January. This allowed the children to have a few days to transition to online courses before we moved. The children each brought a chromebook for school, headphones, mechanical pencils and pens to Germany.

I set up an appointment with folks in Germany (through the university and the cultural integration office) to find classes and extracurricular activities for the children. I found it helpful to be in touch with everyone involved and to be patient. Online school and life in Germany were different, and as a result, I was not always sure what questions I should ask. It took me awhile to wrap my head around what routines and schedules would look like.

Making the trip.

My children and I each packed one big suitcase and one big carry on.

They liked having a say in what they packed. A packing list helped, since that provided the guidelines for them. I packed a second carry on bag for extra items that was only half full. This way, we could manage our luggage from Madison to Aachen by plane and train. My daughters deviated from the packing list and added a few extra dense items (games, books, and lots of liquid toiletries). Two of our bags were overweight by a few pounds. My set cover approach was thwarted! But it worked out. I was able to tuck a few items into the half full carry on. When we picked up our luggage in Frankfurt, everyone was able to manage their own bags on the trains, and we made it to our new home in one piece.

Our new apartment was not fully furnished. I had to come up with a plan to furnish it ahead of time. I placed an order for IKEA furniture a week before I left and chose a delivery time for the day after I arrived. IKEA in Germany does not have next day delivery, and orders are delivered about a week after they are placed. I was incredibly nervous about my plan, but it worked perfectly. It was thrilling to get the delivery. We could get settled into our new home. The best part was that when my kids put together furniture and arranged their rooms, it helped them feel like it was their new home. I’ll write more about our first steps in Germany in another blog post.

In summary

The title of this post refers to Angst, because there was so much to worry about and so much in the air. This weight was most acute when it came to my concern for my three daughters. I felt the weight of this uncertainty and angst the most the month before leaving for Germany. I knew I would be find and could roll with the punches, but this trip was entirely new to them and was a stressful new experience. I was relieved when pieces of the planning fell into place.

In my next sabbatical post, I will blog about first steps in Germany. Read more blog posts about my 2020 sabbatical here.


STOR-I Masterclass at Lancaster University

Last week I traveled to Lancaster, England to teach a research masterclass at the Centre for Doctoral Training (CDT) in Statistics and Operational Research (OR) in partnership with Industry (STOR‐I) at Lancaster University. STOR‐i was established in 2010. It is funded by EPSRC, Lancaster University and a wide range of industrial partners. It’s goal is to use industrial challenges as catalysts for innovation, and the Centre’s primary aim is to develop future international research leaders in statistics and OR. A masterclass is a series of introductory talks on an area of contemporary research given to the PhD and Masters students enrolled in the program.

My masterclass was entitled “Public sector operational research.”

A brief description:

Public sector applications, such as those in fire and emergency medical services, are complex systems that span people, processes, vehicles, and critical infrastructure. Researchers have been developing optimization models to locate vehicles such as fire engines and ambulances and spatial queueing models for analyzing public safety vehicle deployment decisions for nearly 50 years. A body of literature for locating and dispatching vehicles has grown to lift simplifying assumptions and address important issues overlooked in the early research models in this area. Public sector applications such as homeland security, disaster preparedness and response, and critical infrastructure protection have received a growing amount of attention from operational researchers in recent years. However, many research challenges remain.

In this STOR-I masterclass, we will study the evolution of operational research in the public sector with application to public safety, homeland security, and disasters. Technical topics include network optimization problems, facility location and covering models; network design, restoration, and interdiction models; spatial queueing models; and discrete event simulation. Policy insights as well as issues relating to putting the results into practice in real-world settings in the United States and abroad will be discussed.

Readings I used in my lectures:

  1. Larson, R.C., 2002. Public sector operations research: A personal journey. Operations Research, 50(1), pp.135-145.
  2. Green, L.V. and Kolesar, P.J., 2004. Anniversary article: Improving emergency responsiveness with management science. Management Science, 50(8), pp.1001-1014.
  3. Reuter-Oppermann, M., van den Berg, P.L. and Vile, J.L., 2017. Logistics for emergency medical service systems. Health Systems, 6(3), pp.187-208.
  4. Albert McLay, L., 2015. Discrete optimization models for homeland security and disaster management. TutORials in Operations Research (pp. 111-132). INFORMS.
  5. Simpson, N.C. and Hancock, P.G., 2009. Fifty years of operational research and emergency response. Journal of the Operational Research Society, 60(sup1), pp.S126-S139.
  6. Ansari, S., McLay, L.A. and Mayorga, M.E., 2017. A maximum expected covering problem for district design. Transportation Science, 51(1), pp.376-390.

The masterclass was given in three two hour classes. While I was able to cover a lot of ground over six hours, I had to keep the scope relatively narrow so that we could discuss in depth. I decided to mainly focus on facility location models for siting resources for responding to routine and large-scale disasters.

Goals for the masterclass

Class 1: Public sector OR overview

Understand the history of public sector OR (in the US)
Evaluate when and how to apply public sector OR models
Understand features of emergency medical service systems and identify how these features can be represented in OR models

Class 2: facility location for emergency medical services

Understand and interpret facility location problem features
Apply facility location models to locating ambulances
Model how to locate ambulances by including increasing levels of model realism

Class 3: large-scale emergencies and disasters

Understand disasters concepts
Understand and interpret emergency management concepts for OR modeling
Apply OR models to disasters situations

I enjoyed getting to know faculty, lecturers and students. For example, I found out that there were three Slytherin in the class of about 40.

Six hours of teaching is a lot of teaching, and I’m grateful for the students who gave me their undivided attention for so long. One student had studied at RWTH Aachen (my host institution in Germany) and gave me a list of recommended things to do.

Read more blog posts about my 2020 sabbatical here.