Indoor playground

 My toddler seemed to know today was Sunday. He urged me to go to the shopping centre, so I had to put him into a pram and push him there. As soon as we arrived at the outdoor playground on Level Two of Westfield Chermside, it started to drizzle. After a while, heavy rain was pouring down. We moved back indoors, wandering around the shopping centre for an hour, and then went back home at his request.

After his older brother finished his gymnastics class, we drove to an indoor playground in a neighbouring suburb. It was very crowded today, maybe due to the rain. The two boys took off their shoes and swiftly climbed into the play area. I followed them to supervise. I had to bend my back as the height inside the facilities was too short. The older brother ran too fast, quickly skipping past a number of obstacles until he could no longer be seen.

"Where's my boy?" I said while climbing and searching. The little one followed me to help find his older brother. After spending a couple of minutes, I eventually found him on the top level. "I see you!" I cried out. He merrily ran away, asking me to catch him again. After a few runs, he said, "Daddy, could you pretend to be a monster and play the monster game?" I agreed and modulated my voice. "I'm a monster to catch you boys! Wow!"

The two boys ran away while giggling. When I approached them and stretched out my arms to catch them, they quickly hid near the ladders or slid down the slide. "You can't catch me!" they laughed at me. "Yeah! But I can't play on the play facilities."

There was another little boy who saw us playing and came up to me. He introduced himself and said, "Let me join you." Soon after, he became a friend to my older son.

Whether it was because of the weather or the crowdedness of the playground, we felt very sweaty. In a short time, the boys' hair was completely wet. We stopped for a while, bought some snacks, and returned to play after eating.

On the way home, I asked the brothers, "Are you very happy today?" No one answered me. I turned my head back. The little one had fallen asleep with a smile. The older brother also seemed to be tired and exhausted.

Playing with the children was such great fun that I felt as though I had returned to my own childhood. I didn't have the opportunity to play in a similar environment when I was a child. Therefore, I viewed playing with the brothers, to some extent, as compensation for my past.

My Self-study of Classical Guitar

After a few years of living in Australia, I wanted to learn a Western musical instrument in 2013. At first, I considered the flute or recorder, but they were too close to the Chinese dizi and xiao that I was playing, and I did not want to stop what I was used to. Later, I thought about the violin, but I did not think Grandma would support it as the sound was too loud. Eventually, I found the classical guitar, which generates a warm and gentle sound. Holding a guitar against my bosom was like cuddling a lover to sing gently. However, due to the study burden, I did not have time to learn it. This plan was temporarily postponed.

Regarding my study at QUT, I was grateful to have a principal supervisor who appreciated me a lot for a long time during the course. However, the situation changed dramatically after I came back to Brisbane from the ICCV conference at the end of 2013. He had no longer supported me for anything and instead intended to delay my graduation with irrational reasons. I could not understand the sudden change, which was too unexpected, but I argued with him, saying, "I studied day and night, from Monday to Sunday, with the purpose of graduating earlier. Thus, I think the time I spent in three years was equivalent to another student who studied for five years."

I knew I was lying to him as I didn't study that much, especially compared to some classmates like Kien, Ahilan, and Rajitha. But what else could I do? "Ah, I should strike!" I thought. Therefore, in the following couple of months, I didn't study at all. Instead, I bought a classical guitar from a local music store and learned it by myself. It was still not totally by myself, as I watched a lot of YouTube videos during that period.

Seeing my progress come slowly, I felt I had become a useless human resource in the eyes of my principal supervisor. He finally agreed to let me finish the course. My classical guitar playing then had to be interrupted when the final seminar of my degree was scheduled.

At the end of 2014, I joined the BPM team led by Arthur, who had appreciated me a lot some years ago. However, in a professional development review at the end of 2015, he stood on Moe's side to blame me significantly, using some irrational reasons. He seemed to be very unwilling to do that, but I could not understand why he, as the leader of the team, had to do something that he didn't want to do under Moe's request.

At home, I resumed my guitar playing. Despite still not being able to play anything smoothly, the gentle sounds did soothe my broken heart. When I touched the strings, my heart found a remedy through my fingers.

 My contract with QUT terminated in early 2017. Before I went to China for a job at Shenzhen University, I practised a lot. From then on, I could play a simple melody.

As soon as I arrived in China, my parents bought a metal-string acoustic guitar for me. They knew I'd suffered a lot. They hoped the guitar could give me some delight in life. They urged me to find a teacher. I had a couple of lessons with a teacher in a musical training centre which was mainly for young kids. I quit later as I didn't think it was that useful. My understanding of music was different from the teacher's.

After my marriage in 2019, I started classical guitar practice again. I began to watch tutorials online. I felt the online lessons were wonderful. I even purchased a few courses on platforms like Udemy. Slowly, I made progress every day. I learned the alternation of fingers during playing. I learned to play chords. To accompany my guitar playing, I learned music theory, composition, playing guitar while singing, the care of fingernails, and changing strings. There was much practice required for every one of these aspects.

Later, I investigated using a guitar strap to play guitar while standing. From 2025, I've practised almost every day.

 Practising guitar has integrated into a routine for my daily life. Many a night, I am holding a classical guitar, cuddling it like a beautiful lover, plucking the strings gently, as if murmuring with a lover, and devoting myself to the world of music. Then, my soul is relaxed.

Talking from Nobel Prizes

 The Nobel Prizes in 2026 were announced last week. As usual, the announcement of the Nobel Prizes can always be controversial and trigger much discussion. When the Nobel Prize for Physics was announced in 2024, a familiar name caught my attention: the winner, Geoffrey Hinton. He is, of course, one of the most famous machine learning pioneers alive. However, shouldn't his research be in a field other than physics? Yeah, the name of his machine learning model is the Boltzmann Machine, but there is little connection to the physical world, which is similar to two different people with no connection sharing the same name.

In late 2013, when I was conducting research in computer vision, Clinton suggested a reference about facial expression recognition to me, which was based on a variation of the Boltzmann Machine. I found Hinton's paper published in 1984. This was the first time I had encountered a paper that was too challenging to understand in a short time. Maybe I had too many challenges to tackle during that period, making my progress slow. In addition, Sridha seemed to have changed into another person since I came back from attending ICCV 2013 in Sydney. He no longer appreciated or supported me. Nevertheless, the difficulty of understanding the Boltzmann Machine made me lose some confidence. I was very glad in 2024 to see Hinton awarded a Nobel Prize, which meant the paper itself was hard enough.

During my days in academia, I was grateful to work with someone who had the same capability as any Nobel Prize winner. I mean Professor Wil van der Aalst. He was the first author of the C-YAWL paper, but I didn't know he was that famous when I was working on C-YAWL. In fact, his contributions could definitely be awarded two Turing Awards. At the end of 2014, he visited QUT. I told him that I was the master's degree student from several years ago who did the C-YAWL development, and that I was glad to meet him, the first author of the paper.

"Ah, I see! You did C-YAWL!" He sighed and said he was really very glad to see me in the BPM team. I told him that I'd finished my studies and migrated to Australia.

"You should be very glad to settle and work here. I know many people in China want to migrate to Australia, as I often visit Tsinghua University," he said. He gave me a gift, which was a school bag that QUT had given to him.

My job in the BPM team at QUT was not going smoothly. Rather, I thought I had been bullied by my supervisors again and again. I didn't know why. In the end, I lodged an official complaint—not about the bullies, but about the authorship matter of the C-YAWL paper. I thought Wil would stand by my side. However, he denied my contributions, which left me rather shocked. In fact, I just wanted to have a reconciliation on that matter at the time. I think the authorship of the paper will eventually damage his reputation if he cannot achieve a reconciliation with me.

One day, in my university dormitory roommates' WeChat group chat, I said I didn't think those with Nobel Prizes or Turing Awards were really all better than me in research. At the very least, I was better than Professor Wil van der Aalst in process mining, and much better than Professor Simon Lucey, who led the Australian Machine Learning Institute in Adelaide. My roommates laughed at me. I found it hard to explain it to them. I was disappointed that they didn't believe me, so I quit the group without any hesitation.

Outdoor Painting

Yesterday we went to the Emergency Services Expo in 7th Brigade Park, which was not far from home.

I noticed this event through a painting group on Facebook called “Urban Sketching”, which organises outdoor sketching from life around Brisbane every week. Since I picked up my painting brush again last year after abandoning it more than 20 years ago, I have mainly painted individually, with occasional play sessions with my young sons. I have longed for communication and discussion. That’s why I suggested going there, imagining I could even make friends with the same hobby.

It was hard to park our car. We drove along the edge of the park and parked our car in a quiet street nearby. We were surprised to see so many activities and various types of vehicles, including police cars, ambulances, fire engines, and bin trucks. My toddler was most interested in playing on the jumping castle, and my older boy was excited to get lots of toys from each organisation, which were positioned under umbrellas.

“Where are the painters in the Facebook group?” I puzzled. After a while, I found an old man sitting on a bench in a pavilion, with a large sketchbook on his lap. I wanted to say hello to him but decided to hold off for a while, as I thought I should finish those activities with the kids and then went there to draw together. A pavilion with a water tap next to it and surrounded by trees was a wonderful spot for painting landscapes from life.

However, I underestimated the number of organisations at the expo. When we finished walking around and participating in those activities, it was already afternoon. When I arrived at the pavilion, nobody was there. Later, I saw a group of people gathering underneath a big tree where there was a great shadow, which was precious on this very hot summer day. On the ground, there was a pile of sketchbooks lying around.

I went to greet them and said, “It is a pity that I missed the painting session as my boys were attracted to the games.”

“Yeah, you cannot paint anything with young kids. Members in the group are basically in the retirement age range, but we organise events every week. You’re welcome to join the next activity.”

We returned to the pavilion, brought out the painting tools and paper, and the two boys merrily started to create their artworks. It was still fun to paint in the open air, despite still only being with my two young boys.

My Journey to Cantonese Opera

My classmates did not believe I could speak fluent Cantonese when I had just started my bachelor's degree course at Xidian University. "We know a lot of people migrating to Guangdong Province!" they said. In their minds, I was one of them. I then explained that my ancestors had been settled in Southern China for a long, long time. There had been at least several generations in my hometown before I was born. They didn't believe this, as they thought my Mandarin was too good, and most significantly, I didn't know any Cantonese pop songs from Hong Kong.

Until one day, we went to a KTV, and I was urged to sing a song. I browsed the list of songs on the machine and couldn't find a song I knew, as I seldom sang pop songs. However, I quickly glanced at the category and found the item "Cantonese Opera." I then sang a piece of famous Cantonese Opera—Fragrant Sacrifice （香夭）from Princess Flower (帝女花）. From then on, everyone in my class knew I could speak Cantonese, as everyone knew Cantonese Opera had higher requirements than normal pop songs. In reality, Cantonese is my mother tongue. The people in the area where I grew up speak standard Cantonese, whereas people from my hometown village speak a different dialect. But I had left the village at the age of four years old.

Mum and her mother, who was my grandma, were enthusiasts of Cantonese Opera. From an early age, I was submerged in Cantonese Opera music. Traditionally, in the region where I lived, both Cantonese Opera and Cantonese music had flourished in history. Despite this, those traditional cultures had declined, especially in our generation. Grandpa often bought us a large volume of cassettes of Cantonese Opera from Hong Kong. Almost every child has a period of rebellion, especially around puberty. I know I was an exception to this. From childhood to adulthood, my mum has been the most important person to me, and I always listen to her. Her influence on me is always much stronger than that of any of my friends.

Therefore, when all my friends became interested in pop music, I still stuck to Cantonese Opera. Intrinsically, I think there are other reasons which may be more dominant. First, I loved traditional literature, especially poems. In senior high school, I was the best student in this area in my class. The language used in Cantonese Opera was close to traditional poems in China. Second, I was keen to listen to complicated music. The structures and melodies of pop music are simply too simple to my ears. Third, I liked to play Chinese bamboo flutes, dizi and xiao, which traditionally are used for Chinese traditional operas. Fourth, I have a good voice with a wide pitch range that allows me to sing both the male and female characters.

I had been addicted to playing the xiao during the time when I lived in Xi'an. Mostly I played Cantonese opera music. I keep this hobby as my daily routine until now. The stories in Cantonese Opera have given me much inspiration and taught me a lot, which includes history, traditional values, and literature. In the days of research, I often listened to Cantonese opera music while conducting research.

In early 2012, I applied for a tutor position at a university when I was studying. A programme leader said he wanted to appoint me as a lecturer. However, this triggered huge objections from others in the same research group. "He is not good at English!" "Opportunities should be first given to people born in Australia!" "He doesn't like to work with others." "It seems he is rather confused." "How ridiculous to work on weekends to try to graduate earlier, which I've never heard of!" "Why give that many opportunities to an overseas student from China?" As I didn't want to hear any of these words, I put on a headset, opened YouTube in the browser, and listened to my favourite Cantonese opera music.

In recent years, I've read some books to know more about this traditional art. I noticed that the education systems for Cantonese opera were different between Hong Kong and Guangdong Province. 

I like Cantonese Opera. It is the traditional culture of my hometown. I'm proud to be from a place with such a treasured culture.

Sowing

Mum had harvested vegetables in the vegie patch of our front yard, leaving an empty space with no plants. "Do you want to plant some flowers?" I asked the two boys. "Yes, to plant flowers!" they agreed merrily. "What do you want to plant? Sunflowers, bougainvilleas, roses, or others?" "Sunflowers! Yellow flowers!" Sunflowers seemed to be their preferred choice.

The other day when I was at Woolworths, I purchased two bags of seeds: one for sunflowers and the other for wildflowers in various colors. After the older brother finished school, I led them to the garden patch. I showed them how to use a spade or a shovel to dig a hole and then put seeds inside. Finally, I told them to cover the seeds with soil. "In this way, the magpies will not be able to find them. Otherwise, they will fly here to eat them," I said. The last step was, of course, to water them.

To encourage the boys in their gardening work, I purchased an elephant-shaped watering can from Kmart for them. "To have flowers, you have to water them every day!"

I think it is very meaningful to guide the boys in sowing flowers. Sowing is the effort that we devote. Don't envy the flowers in your neighbors' gardens. If you want your garden to be flourished with petals, you have to first sow!

About Simulation Techniques

The final project of my undergraduate degree, which was entitled "Multicast Switching Technologies in High Speed Routers", was supervised by Associate Professor Fan Yang. I chose him to be my supervisor as I had a very positive impression of him in his lectures on switching technologies. One day I sent him an email to discuss a statement from the textbook, which had made me rather confused. "Your understanding is correct, and the way to express the idea in the textbook is a little misleading," he responded quickly. "How would you like to do the project?" he asked me. "If you really want to do an excellent project, I can guide you to use a couple of network simulation tools such as NS2 or OPNET." "Yes, I want to try my best and learn as much as possible from it!" I said with a determined voice.

However, I soon became regretful for this. In the final semester of university, I first devoted myself to finding a job. I wanted to find an employer who could allow me to break the contract with ZTE. After many unsuccessful attempts, I had given up. Instead, I used almost all available time to prepare for taking the IELTS test, with a plan to study in Australia. After finishing the examination, it was merely a week or so before the due date of the final project. At the time, it had no longer been enough for me to learn those simulation tools. I was thinking of writing a program by myself from scratch. I wrote an email to my supervisor about the basic idea, and he confirmed with me that the basic idea was rational. Therefore, in my final project report, there were a number of pages of a C program appended, which simulated an algorithm from a paper. It was a console program without any visualization. What the program did was simulate the algorithm to calculate throughputs.

In July of 2008, when I'd just graduated, I was engaged in the training program for fresh graduates in ZTE. I was assigned to the department of CDMA network planning and optimization. In the real world, network planning typically relies on simulation as the initial step. This is because setting up a wireless network is of high cost and complicated. Many calculations are done inside the simulation tools. After the installation of network facilities, a road test is compulsory to test the signal strength in every corner of the place, and adjustments are usually needed as a later step.

In 2009, I enrolled in a course at QUT in Australia. In the second semester, I enrolled in a unit about operating systems. The virtual machine is a type of simulation which simulates the hardware from the ground up. At the same time, I was doing a project in the Microsoft eResearch Centre. The project was related to the Windows CE embedded system, where simulation was used as a tool for development.

In early 2010, I enrolled in a unit called "AI for Games", which taught computer games agent development. This was probably my favourite unit at QUT. In this unit, we explored the OpenSim platform, an open-source project written in Mono.NET. It was a Second Life simulation platform. Various algorithms had been learned during this time, with the honey bees optimization algorithm, the Mini-Max human chess competition algorithm, and the distributed behaviour models that used to model collective behaviours among the most impressive ones.

Several years later, I began to draft a thesis on the topic of "Unusual Event Detection in Crowded Scenes" in the area of intelligent computer vision. I realized that many abnormal events with security interest are impossible to obtain with a sufficient number of instances in real-world surveillance footage. "When we can't get them in the real world, how do we test them?" I wondered. Then I suddenly thought of the OpenSim simulation that I'd learned before. If the videos generated by computer graphical simulation were not looked as real enough, I thought we could also use a set of robots to simulate. While a group of robots moved together, we could apply the distributed behavior models to simulate movements in the real world. Then in the conclusion chapter, I said cross-disciplinary research, such as including simulation techniques, was compulsory in this research topic.

In 2015, I was working on a paper on resource allocation management in the area of process mining. We first used simulated data with a well-known ground truth to evaluate the algorithm in ideal conditions. Then we applied it to a real-world dataset, and verified it with business feedback. Professor Wil van der Aalst, who was the "father of process mining", had given the section I drafted very positive comments, which I had been very proud of until now.

However, I do believe simulation is overused in telecommunications engineering research. I've read many papers in these areas, and many of them only have simulation-based results. I've always considered those papers as incomplete. "When are you going to start simulation?" Professor Huang urged me when he was pushing me to have a paper in pattern recognition, where simulation was rarely used, when I was working in Shenzhen University.

In around 2020, I started some development for mobile applications. Simulations for different models of mobile devices were used extensively to develop mobile apps on a desktop computer.