Saturday, February 25, 2023

Scuba Diving Certification

On February 12th, 2023, Lily and I finally achieved one goal we set quite sometime ago - certified to scuba dive.

Ever since we saw the beautiful fishes and other marine life and the world under the water from a snorkeling outing at Cancun more than 5 years ago, we thought about to go a step further - scuba diving. But one has to be trained and certified for scuba diving due to the inherent risks involved, just like driving. 

We set a goal to take scuba diving training and get certified but had never put it in action until January 2023. We decided not just to plan it, but to take real actions - we booked and paid for the training for February, less than a month away!

The training includes 3 steps - 1) computer session - learn the basics of scuba diving and pass a knowledge exam online, 2) pool session - practice in a pool what we learned on paper with guidance of a coach, 3) open water session  - practice  in the ocean what we learned on paper and in a pool. 

We took the PADI training - a training program designed and licensed by Professional Association of Diving Instructors. PADI certification is recognized world wide.

Scuba Diving Basics - online learning

The online course is organized into 5 sections. There is a knowledge review quiz at the end of each section. When all 5 sections are completed, there is a exam with 50 questions, passing grade is 75%. 

The course is fairly easy, requires only basic middle school physics to understand the fundamentals of scuba diving - which involves  descend/ascend in water, breathing using scuba unit, purge water in mask and second stage - the mouth piece for breathing with the air tank, how to act in case of emergency.

Individual items are easy to understand and follow. But in reality one needs to coordinate many actions to be safe - like during descend, one needs to control descend speed but frequently inflate buoyance control device (BCD) in small amount, and to equalize pressure in ears or masks, and to stay close to diving buddy, and etc. I felt overwhelmed and anxious going to my pool session, even though after 1 week daily study after dinners, I passed all knowledge quizzes and exam in flying color.

One thing I liked to highlight and emphasize is the hand signals, I did not pay too much attention to them, and did not remember all of them. Hand signals are the only ways divers communicate with each other in deep water.

Pool Session - practice in controlled/clean environment

Pool session took place on Tuesday evening at the alumni association's pool. There were 4 students in the class - the other two students were female college students. 

With brief review of what we needed to do in the pool session, we had a couple of quick checks: first swim 200 meters without stop, second hold breath and then bury head into water and blow air throw nose as long as possible.

We learned how to assembly scuba unit, how to use it. We went under water, to exercise a few key skills, 1) purge water from second stage and mask, 2) share air, 3) stay neutral buoyance, hovering.

One student in our group had trouble stay under water because water kept seeping into the student's second stage and/or mask. She went up to water surface a couple times despite the coach's instruction not to surface. The rest of the group, including me stayed under water for quite sometime breathing on regulator. I had no issues at all and my concerns with scuba diving dissipated.

The session lasted about 4 hours. We felt really cold half way through the course despite wearing wet suite due to long stay under water. I threw up a little bit  after getting out of water at the end of in-water training, fortunately I could hold long enough time to get to bathroom. 

Open Water sessions  - practice in natural environment 

We went to Pulau Hantu for our open water sessions on two consecutive days, Saturday and Sunday (February 11 and 12,2023). 

We had to get to the pier by 7am on both days for 7:30am departure on a chartered boat. We treated it like a major trip, had everything ready the previous night, slept early for early rise at 5:30am. After a light breakfast, we left home around 6:20am, and got to the meeting place 6:40am, way ahead of schedule. Likely due to jittering, we used restrooms again upon arrival. When we were back to the meeting place, one of the female college student was there waiting. We chat with her briefly. She is a college student majoring in sports science, and scheduled to go on a scuba diving trip at Bali, Indonesia, in March.

The coach arrived right on time at 7am. We boarded the chartered boat, and we were not alone, there were two other scuba diving classes (from other providers) who shared the boat with us.

On the boat to Pulau Hantu

On the boat to the island on the first day, the coach had a quick briefing with us at the stern of the boat, overview what we need to do and practice.

After the meeting we first checked the air from the tank, assembled the scuba unit, checked air pressure, and functionality of all devices - second stage, LPI - low pressure inflator, alternate air source, BCD. Then we put weight on the weight belt and put it on, followed by put on the scuba unit, and at the edge of the boat, put on fins.

getting out of water from 1st open water session

The one thing we did not practice during pool session is the giant stride off the boat and into water: 1. enter water fully equipped, with BCD partially inflated. 2. breath through regulator. 3. left hand hold scuba unit console, right hand palm on regulator, finger on mask. 4. Look ahead (Not down) and walk forward  - keep legs open while falling.

students lined up by the boat after giant stride entry - 2nd session

The other thing is equalizing while descend. I did feel discomfort in my ears while descending. So I pinched my nose, and blew through nose, and equalized my ears. If the mask needs equalization, then one should tilt head back in vertical position, and blow through nose.

The third thing is controlled ascend. This is very important, very fast ascend can cause decompression sickness, in serious scenarios it leads to collapsed lung and potentially death.

We practiced purge air from second stage, replace second stage, share air, hovering as well. 

The descend and ascend during the training sessions were all through ropes - so the speed was controlled by the first to descend or first to ascend, the coach monitored the first person closely. So we did not really practice all skills related descend or ascend.

On Saturday we dived twice, each time about 35 minutes under water. The visibility in water was not great at all, but it sufficed to do the open water practice for scuba diving. The problematic student had the issue as that happened in the pool again during the 2nd dive, and she had purple lips! We finished training by 10:30am. We dried up and went to the top deck chat and waiting for return trip.

We had more conversations with our classmates, the second student was actually a study-abroad student from UK, she majored in marketing.  We talked about food, weather, free of street safety concerns etc. Since she is marketing major, I asked her about chatGPT. She lighted up about the topic and we talked about chatGPT for quite a few minutes.

We were more relaxed on Sunday, we actually got up later on Sunday and arrived at the pier at 7am, but jittering was still there we did not really sleep well. Two good developments on this day: The student who had problem diving before, figured out what caused her problems, and had no more problems during 2nd day diving; The sport science major student brought her Gopro underwater camera, and we got some pictures taken under water ! A fifth student, a male, joined us on Sunday for a make-up session.

On the second day at sea, we did pretty much the same as day 1, but this time we demonstrated to the coach that we mastered the required skills for certification.


At the end of our second day diving, after completing all checks, we swam under water for a while, with coach leading the way, to see corrals, fishes and marine life in 10 meter deep water by the island. Unfortunately there was not much to see.... a handful transparent fishes, and some sad corrals.

Most importantly all students in the group were certified for open water scuba diving.

Lined up for photos after final ascend - Sunday


 



  



Saturday, February 18, 2023

chatGPT - my chat with chatGPT and more

I heard about Dall-e and chatGPT late 2022, both are based on GPT AI architecture. Note that GPT stands for generative pretrained transformer. I tried Dall-e-2 a couple times*, but I did not probe them further.

By the end of January 2023, there were a lot of chatters on social media about chatGPT. Some friends and professional colleagues started to share their experiences with chatGPT on social media. I was intrigued by various claims - some neat capabilities of chatGPT, some blunders; believers hyped it, doubters dismissed it. I decided to try it myself.

Chat with chatGPT about chatGPT

I had a lengthy chat with chatGPT, completed in several sittings.

Basics of chatGPT

chatGPT was developed by OpenAI, which was funded in 2015, as a non profit organization. It spun off its commercial business as Open AI, LP in 2019. Open AI was the developer of GPT, GPT-3.

The GPT model is based on the transformer architecture, which was introduced in a 2017 paper by Vaswani et al (Google Brain program) 

Model size: OpenAI's GPT-3 (Generative Pretrained Transformer 3), which is the model that chatGPT was trained on, has approximately 175 billion parameters.

Training data:GPT-3 was trained on a massive amount of text data from the internet, including web pages, books, and more. The exact amount of data used for training is not disclosed by OpenAI, but it is estimated to be in the range of hundreds of billions or even trillions of words. The training process involved fine-tuning the model on this data to generate high-quality text output.

Training time: The exact duration of the training process for GPT-3 is not publicly disclosed by OpenAI. However, training a large-scale language model like GPT-3 can take several months to a year, depending on the amount of data used and the computational resources available. It is a computationally intensive process that requires large amounts of computing power and memory.

Knowledge cut-off: The knowledge cutoff of 2021 for GPT-3 (and for chatGPT as a language model based on GPT-3) is not directly related to the time it took to train the model. Rather, it is because the training data that was used to fine-tune the model only included information up until 2021. As a result, the model may not be up-to-date on more recent events or developments that have occurred after that time. This is why it's important to note the knowledge cutoff when using a language model like GPT-3 or me for information or content generation.

Here are some more interesting Q/A:

Allan: back to the previous training question, 175 billion parameters for the model, that sounds like a brute force approach to train you.


Allan: what I observed so far about people using chatGPT to solve their problems...the problems have answers in literature already. is this accurate?


Allan:
can you generate new knowledge?


Allan: can you learn from your chats from users real time or in short time?**


Allan:
it is interesting to talk to you about you. here is a philosophical question. We know that with GPS/google map many people's ability to remember driving route has deteriorated a lot. Quite some people can not drive without GPS guidance. Can the same happen with chatGPT applications in some way, for example, chatGPT will make human more efficient and retarded at the same time?


Limitations of chatGPT


Allan: besides the three limitations outlines in the front page of chatGPT, any other things I need to pay attention to when using chatGPT?

 

Allan: why is it so hard to ChatGPT to have common sense reasoning?


What can chatGPT do?

answer questions with a high level summary no reference provided(tried)
do limited literature search (tried)
write poems/essays (tried)
write code in many languages (tried FOTRAN, visual basic)
debug code (not tried)
write music (not tried)
create/tell a joke (tried)
analyze data (have not tried)
manage work schedule (have not tried, I wonder why people needs AI to schedule individual's work, large organization, maybe)
therapist ( have not tried)
multilingual (tried - English, Chinese)
extract data from text (not tried, sounds very useful!)
 with API, it can do a lot more
Google search companion
write marco or visual basic code for excel spreadsheet ...
….
If you want to ask chatGPT to do something for you, and you are not sure if it can do it for you, just ask it - if it can or not, if can, how.

Some technical stuff about chatGPT

Allan: I am not familiar with AI technology. could you give a few examples of AI architectures?

Allan: what are the main differences between transformer architecture from other ai architectures ?


Allan:
chatGPT was trained by large corpus of text. if the corpus of text was input, what was the output used in the training?


Clever!!

A little bit more in depth explanation on how chatGPT work, can be found in this article


Snap reactions

chatGPT is a good tool, very conversational.
Know its limitations and deficiencies - don't blindly trust it
Using chatGPT, AI to you advantages - enhance you real natural intelligence


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* What I asked Dall-e-2 to do is to draw a bridge to the Moon. I did not get what I expected. So I asked it to draw a bridge under the Moon, everything looks good this time. I changed the prompt to a bridge that connects earth to moon. It seemed that Dall-e-2 was trained for scifi type of drawings.




** sometimes it may seem that chatGPT learns from the conversation, it is because it frequently recap a conversation, especially if it is a long one.