yoursunny blog
computer, Internet, and life

My Last Month in Tucson

Junxiao Shi

I began my life as a Tucsonan on Aug 04, 2011, spent six years as a PhD student at The University of Arizona. However, everything has an end, and my life in Tucson ended on Aug 31, 2017, after I accepted a research job in Gaithersburg, Maryland.

Move to Sahara Apartments

My apartment lease at University Arms Apartments ended on Aug 01, 2017. I needed one more month in order to finish editing my dissertation. I chose Sahara Apartments for my short-term accommodation.

On Jul 15, I went to Sahara Apartments to "apply for a room". I received a tour promptly, but I was told to apply online, because they do everything online. Despite being a small community, Sahara had a complicated website for all the business procedures, including new resident application, rent payment, maintenance requests, shuttle reservation, and policy violation reporting.

I put in my online application a day later, and received an invoice within a few hours. The invoice indicates that paying by credit card would incur a 4% convenience fee, and paying by personal check would incur a five-day delay to make sure the check clears. WTF?

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Chinese Gym vs American Gym

Junxiao Shi

After graduating from University of Arizona, I went back to China for six weeks to apply for a new U.S. visa. Since weightlifting has become a part of me, I continued my workouts in a Chinese gym. The experience there is significantly different from American gyms.

Annual Membership, Please

Most gyms in China only sell annual memberships. Gym managers are secretly wishing that you would give up your ambitious exercise plan after several weeks, so that they could profit off you without devoting resources. My stay in China was six weeks, so an annual membership would be overkill and prohibitively expensive. I had to find a gym that offers single tickets. My gym of choice was "Fitness Club" (菲特妮斯健身会所) located in the basement of a grocery store. They agreed to offer me single tickets at ¥50 per visit.

In United States, most gyms are happy to sell you a day pass. Some gyms even offer a few free tickets so that a potential customer can experience the facility; this is also perfect for short-term visitors.

In terms of price, ¥50 per visit is about as much as $8 charged by University of Arizona Campus Recreation Center. However, personal income in China is much lower than the United States, which means a Chinese gym costs more than an American gym for local people.

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Shocking Changes in China

Junxiao Shi

After six years in Arizona, I graduated from The University of Arizona, and returned to China on Sep 01, 2017. My previous returning to China was in 2014, and China has changed greatly during my three years of absence.

Swipe Your Face

Fraud is a serious problem in China. The "standard" countermeasure is two-factor authentication, i.e. a random code sent to your phone. However, fraudsters have been able to convince the victim to reveal the random code on their phone. A stronger countermeasure is doing all transaction in person: you have to show up at the bank or phone company, and present your ID card. However, there are usually long lines in those places and thus it's not a pleasant experience.

The regulators invented a new way: "swipe your face". I bought a SIM card for my smartphone online. To activate my account, I must upload a picture of my ID card, and record a video of me acting according to a series of random instructions. The instructions could be: "blink your eyes, open your mouth, rotate your head to the left". The system would then analyze the video to confirm that I am alive and am the same person as shown on the ID card.

I believe video authentication provides much stronger authentication than asking for "mother's maiden name" and "last four digits of social security number" as most companies do in the United States. It is surely less convenient than answering a few questions, but this is a trade-off for China where fraud is more common.

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Tucson's Museums

Junxiao Shi

Visiting museums is a good way to learn about the culture of a region. During my six years living in Tucson, I found and visited many museums in this city, and here are some of my favorites.

5. Arizona State Museum

Arizona State Museum is located on University of Arizona campus. I knew about this museum since the beginning when I participated in ISA's very first campus race event, but I never paid a visit because I thought it is literally steps away from my office so I can visit "some time". In August 2017, when I'm days away from graduation, I finally visited this museum. My visit spanned two afternoons due to the rich content in this museum.

Paths of Life exhibit in Arizona State Museum

The main exhibit at Arizona State Museum, Paths of Life, presents the origins, histories, and contemporary lifeways of ten Native American cultures in Southwest America. While I have interacted with members of Tohono O'odham and Yaqui tribes through their presentations at Tucson Meet Yourself, I gained better understanding at this Paths of Life exhibit about their culture, religious beliefs, and struggles. I also learned about eight other indigenous tribes in the Southwest region but further from Tucson.

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Tunnel Ethernet Traffic Over NDN

Junxiao Shi

Named Data Networking (NDN) is a common network protocol for all applications and network environment. NDN's network layer protocol runs on top of a best-effort packet delivery service, which includes physical channels such as Ethernet wires, and logical connections such as UDP or TCP tunnels over the existing Internet. Using this underlying connectivity, NDN provides a content retrieval service, which allows applications to fetch uniquely named "Data packets" each carrying a piece of data. The "data" could be practically anything: text file chunks, video frames, temperature sensor readings ... they are all data. Likewise, a packet in a lower layer network protocol, such as an Ethernet frame, is also a piece of data. Therefore, it should be possible to encapsulate Ethernet traffic into NDN Data packets, and establish a Virtual Private Network (VPN) through NDN communication. This post describes the architecture of a proof-of-concept Ethernet-over-NDN tunneling program, and shows a simple performance benchmark over the real world Internet.

The Program

tap-tunnel creates an Ethernet tunnel between two nodes using NDN communication. Each node runs an instance of tap-tunnel. This program collects packets sent into a TAP interface, and turn them into NDN packets. It then gains NDN connectivity by connecting to the local NDN Forwarding Daemon (NFD). The diagram below shows the overall architecture:

IP app                                              IP app
  |                                                    |
IP stack    tap-tunnel              tap-tunnel    IP stack
  |         /        \              /        \         |
TAP interface       NFD            NFD       TAP interface
                     |              |
                    UDP            UDP
                     |              |
                    global NDN testbed

tap-tunnel requires existing NDN reachability between the two nodes. Each node must have a globally routable NDN prefix, so that a tap-tunnel instance can send an Interest to the other instance. This reachability can be established with auto prefix propagation.

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Hiking in Arizona

Junxiao Shi

I was a couch potato before I came to the United States six years ago. There aren't many outdoor adventures in my hometown Shanghai, because Shanghai is located on a flat peninsula, and the only place that resembles a mountain is the 97-meter Sheshan Hill. In contrast, Tucson is surrounded by five mountain ranges, and it is a hiking paradise.

My First Hike

Among the grad students in computer science department, there is an organization called the Graduate Student Council (GSC). On the same week as orientations, I attended the first GSC meeting, and learned about various activities organized by GSC. One of them is a "hiking club". I joined their mailing list, although I did not know what I was signing up for.

The first hike was on Oct 01, 2011 going to Butterfly Trail. I took an early morning bus to school, and brought "plenty of water for yourself, sturdy hiking shoes, lunch, warm cloth" as instructed by the trip leader. We departed shortly after 09:15, and it was a long ride in Jeremy Wright's car.

Butterfly Trail, 01OCT2011

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My Favorite Tucson Restaurants

Junxiao Shi

During my six years living in Tucson, I visited hundreds of local restaurants. Here are my top picks. Those restaurants are all good, and their order within this article does not indicate my preference.

Best on campus: IQ Fresh

crispy fish wrap from IQ Fresh

Located in the main student union, IQ Fresh is my usual place for a quick lunch between classes. They mainly serve wraps: shredded meats and veggies rolled inside a piece of tortilla. They offer 14 different meats and veggies, and 10 tortilla flavors, giving 140 choices.

My favorite is the crispy fish wrap in spinach wrapper, with a side of sweet potato fries. Sadly, this particular item has been discontinued in 2015, and I stopped going there altogether.

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Academic Papers

Junxiao Shi

Writing and publishing academic papers is an essential part of PhD education. During my 6-year PhD career, I published three academic papers as first author in peer-reviewed conferences:

Publishing an academic paper is hard. In the process, I must:

  1. Come up with an idea.
  2. Confirm the idea is feasible.
  3. Design and execute experiments to show the design is superior to competitors.
  4. Write the paper to make others understand my idea and experiments.
  5. Submit the paper, and hope my paper is better than most submissions in the same conference.

The Idea Phase

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Heat and Monsoon

Junxiao Shi

Tucson has four seasons: spring, summer, monsoon, and winter. Located in the desert, the climate is very different from my hometown Shanghai. I have been accustomed to Tucson's climate after living here for six years.

Summer Heat

The summer is extra long. @TheTucsonHeat arrives in April or earlier, and would not leave until Halloween at end of October. Thus, seven of the twelve months belong to the summer.

Heat is the number one weather related killer in Arizona. House cooling is not optional. Heat warning signs are everywhere:

"the heat is on" sign in Joel D Valdez Main Library

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Heavy Iron Stuff

Junxiao Shi

I started going to the gym regularly during my fourth through sixth years at University of Arizona. Weight lifting helped me to lose weight of up to 30lb, and replaced some of my body fat with juicy muscles.

How It All Started

I have been swimming since the second day I arrived in Tucson, but my body looked the same, because my roommate was cooking large bowls of white rice and fatty meats for me. Since I moved to University Arms and started living alone, I decided to change things up. I started running on treadmill and using the elliptical trainer on and off in the Campus Rec. I was thinking to eat less and cut back on ice cream.

I ate only one apple at the breakfast of Oct 14, 2014, and felt hungry two hours later. I wondered, am I eating too little? To find the answer, I decided to calculate how much calories I was eating on that day. I searched online for a "calorie calculator", and found MyFitnessPal. It is not only a "calculator", but also an app to keep track of how much I ate. I made my first entry:

MyFitnessPal food diary on Oct 14, 2014

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