Reborn in 2010, the AI ​​in my mind is too powerful.

Chen Yiran woke up at around 5 a.m. the next morning.

I feel okay physically, no low-grade fever, no dizziness, and it seems that listening to the lecture while sleeping doesn't affect me much.

"Jasmine."

Yes, you're awake.

"How was last night?"

I've taken notes of most of the lessons, but some require referring to diagrams provided by the professor. I've noted down the approximate times for these, and we'll review them tonight.

Chen Yiran sat up and stretched.

That's much more comfortable. It not only saves time, but also reduces the physical burden.

I got up, washed up, and ate some milk tablets. It was still too early, so I turned on the computer and asked Jasmine to look at some TOEFL questions.

I only leave for class when it's time, and then it's another boring day.

To be honest, Chen Yiran has a hard time concentrating in class, and the courses are really not helpful to him.

The teachers also noticed that he often spaced out, but after asking him several questions on the test on the first day of school, they understood his level and basically turned a blind eye.

After a grueling day, I got home and received a call from Xu Li: "Boss, are we going to Philadelphia's Chinatown to do some shopping tomorrow? Liu Ya and Xiu Xiu are going too. They're planning to cook and are going to Chinatown to stock up on groceries. Do you want to come along?"

"Okay, what time do we leave?"

"Shall we meet downstairs at 10 AM?"

"OK."

Chen Yiran opened the course on the computer and said to Jasmine, "Okay, I was going to try to push you a little further today even though I wasn't feeling well, but it seems I can't. I have an appointment tomorrow morning, and I can't let you go looking sick."

[It's okay. I already verified yesterday that I can record my studies at night, and we're progressing quickly. I'll tell you the time and location you need to look at first, then you can find it.]

"Okay, let's begin."

Following Jasmine's instructions, Chen Yiran began to look at the various time points and examine the daunting blackboard writing.

Chen Yiran made another video call home that evening. They had agreed to video call every weekend. This time, with everything settled in, she took her laptop and showed her parents the apartment layout.

The parents were very satisfied with the apartment's facilities and size, but they expressed their disapproval of Chen Yiran's decision to simply stack two mattresses together instead of assembling a bed.

As usual, I'll set up a class for Jasmine tonight. She'll be able to finish the course and welcome a pleasant Saturday.

However, Jasmine's reaction after waking up made Chen Yiran unhappy, but he already had an appointment and would deal with it when he got back in the evening.

After brushing their teeth and washing their faces, the four of them gathered downstairs at ten o'clock sharp.

"Let's go." Xu Li glanced at the two people in the back seat through the rearview mirror. "The boss is treating today."

"When did you say you were treating us?" Chen Yiran asked from the passenger seat.

"You don't have it? Then tell me now."

"...Just focus on driving."

It takes less than an hour to get from Newark to Philadelphia via I-95 South.

The group chatted about their goals along the way. Liu Ya and Lin Xiuxiu mainly wanted to stock up on vegetables. The vegetables at Lao Wang's shop were really hard to describe. They could only be said to be safe to eat, but as for freshness, only a few varieties were guaranteed.

Chen Yiran originally just wanted to get some fresh air, but then she thought about how her mouth had been suffering these past few days and decided to go out for a nice meal. Although she and Xu Li had been going to Zhuyuan to improve their meals for the past few days, Zhuyuan was only good in Delaware and couldn't compare to Philadelphia.

After exiting the highway and turning into downtown Philadelphia, we soon arrived in Chinatown.

Philadelphia's Chinatown isn't large, just a few streets sandwiched between Race Street and Vine Street. But the signs are densely packed together, with traditional Chinese characters, simplified Chinese characters, Korean, and Vietnamese mixed together.

Xu Li found an empty parking space and parked the car. The four of them walked along N10th Street.

The first target is Heng Fa Food Market, a supermarket chain.

Hengfa is located on 10th Street. The storefront is unassuming, but once inside, it's a completely different world. It's much bigger than that old Wang supermarket in Newark.

On the left is the fresh vegetable section, with cabbage, water spinach, pea sprouts, kale, chive blossoms, and a bunch of other common vegetables found in China. The refrigerated display case contains tofu, bean curd sheets, various hot pot meatballs, and frozen dumplings.

On the right was the dried goods and condiments section, with soy sauce, vinegar, cooking wine, Sichuan peppercorns, star anise, cinnamon, and dried chili peppers, all lined up in rows. Chen Yiran saw Wang Zhihe fermented bean curd and Liubiju pickles, and immediately grabbed two bottles.

Further inside is the live fish area, where several large glass tanks house bass, carp, and grouper. One bass jumped and splashed water all over the woman next to me.

The frozen section was even more extravagant, with whole frozen salmon, sliced ​​beef brisket, pork ribs, chicken wings, and a whole bunch of frozen foods I couldn't name.

Chen Yiran hadn't originally intended to cook, but then she thought of Jasmine in her mind. So she bought a bag of Northeast rice and some sausages and meatballs. She couldn't keep eating instant noodles and frozen dumplings if she got hungry in the middle of the night. With rice and sausages, it would be quite tasty to put them in the rice cooker.

Liu Ya pushed a small shopping cart, which was already piled high with vegetables that were not available at Lao Wang's store.

Lin Xiuxiu's side had fruit and snacks, as well as several bags of Thai dried mangoes with fancy packaging.

Xu Li was the most practical; he simply grabbed a whole case of pickled cabbage and beef noodles and put it in his shopping cart.

Chen Yiran was also a little tempted, but after thinking about the 315 performance of Lao Tan Pickled Cabbage, she still went to get a box of Master Kong Shrimp and Fish Noodles.

After leaving the supermarket with their groceries, a few people stood on the street.

Chen Yiran spoke up: "Shall I choose where we eat? Li Kou Fu?"

I've been to this place in my past life. Li Kou Fu is located on 11th Street in Chinatown. It's been open for almost forty years and is a Cantonese restaurant. Their signature dishes are salt-grilled squid and stir-fried beef noodles, but Chen Yiran's favorite is the leek and conch slices.

Xu Li asked in surprise, "Is this your first time here? You even know about Likoufu?"

Chen Yiran calmly replied, "It's 2010 already. Can't you check Yelp before going out?"

The group walked toward 11th Street while talking.

Lee How Fook's storefront is small, with a slightly faded red sign with gold lettering hanging at the entrance. Next to the Chinese name is the English "Lee How Fook". Pushing open the door, there are about ten tables inside, and since it's lunchtime, seven or eight tables are already occupied.

The four people were led to a round table against the wall.

Chen Yiran ordered stir-fried beef noodles, salt-grilled squid, and stir-fried snails with chives. Xu Li ordered honey-glazed char siu, Liu Ya ordered steamed sea bass, and Lin Xiuxiu ordered shumai.

The food came out quickly. The stir-fried beef noodles were freshly cooked, with a great wok hei (wok aroma), the beef was tender and smooth, and the noodles weren't sticky. The salt-grilled squid was really good; it was slightly charred on the outside and still tender on the inside, sprinkled with salt and pepper and minced garlic, and it was very chewy with every bite.

Of course, Chen Yiran still thinks that the leek and snail slices are the most delicious.

The four of them ate for almost 120 yuan. Chen Yiran originally wanted to treat them, but they all put their credit cards on the checkout tray and split the bill.

After dinner, they strolled around the streets. Liu Ya and Lin Xiuxiu went to a small shop selling pearl jewelry but didn't buy anything. Xu Li bought two bags of oranges from the fruit shop next door.

Around 1 p.m., the four of them drove back to Newark.

After arriving home, Chen Yiran put away the things she bought, stuffing the rice into the cupboard and the seasonings into the kitchen.

I had just sat down and taken a sip of water when Xu Li called.

"Boss, some friends asked me to play basketball, are you in?"

"I'm not going, I need to look at my TOEFL materials."

"Alright, I'm off then."

After hanging up the phone, Chen Yiran turned on her computer.

Actually, it wasn't the TOEFL; it was a few questions that Jasmine jotted down last night while listening to CS229.

When Jasmine woke up in the morning, she told him that she couldn't understand many parts of the story.

"Jasmine, say it again, is it something else you need to learn?"

The SVM section in CS229 requires a mathematical tool called Lagrange duality for derivation. It also covers the KKT conditions, the Karlosh-Kuhn-Tucker conditions, which are core concepts in convex optimization.

"I never learned any of this in my past life, so why do I feel like I know it?"

You've heard about these things, and some courses have mentioned them, but you haven't truly learned them.

"Can we learn these directly now? Or do we need to learn something else first?"

From what I understand, only a basic understanding of linear algebra and calculus is required. You already have some knowledge of these, even if it's not exceptional. The textbook material is already in your memory, and I can improve on my own, so you should be able to start reading directly.

"Okay, I'll search for it."

Under Jasmine's instructions, Chen Yiran Googled "convex optimization Lagrangian duality KKT tutorial".

After looking through several results, I found one that explained it quite clearly.

Then I searched for "convex optimization".

The first option is Stanford professor Stephen Boyd's textbook "Convex Optimization," a complete PDF available for free download.

Chen Yiran clicked on it and took a look—over seven hundred pages.

"How about this one? It seems to be a classic textbook."

[Download everything first, I'll go through it. Focus mainly on the chapters on Lagrange duality and KKT conditions; the earlier chapters on convex sets and the definition of convex functions should be quick. Just flip through the pages quickly; this time you can do it even faster. If there's anything I don't understand, I can write it down and try to understand it later.]

Chen Yiran downloaded the PDF and then turned into a page-turning machine again.

[Even faster, I only need to record; one page per second is fine.]

Since that's the case, Chen Yiran started to let loose and, after 20 minutes, lay down on the sofa and began massaging her fingers.

"How's it going? You've memorized everything, haven't you? Did you miss anything?"

No, I've started my comprehension and learning process. You'd better prepare some food beforehand.

"Take it easy, it's the weekend anyway."

I know that ability is a minor issue; if I operate at full capacity, your heat dissipation might not be optimal.

"Okay, I'll go get something to eat first."

Chen Yiran wasn't hungry at all, since it had only been a little over two hours since she had eaten.

But after about ten minutes, he felt his body telling him to eat some more.

Chen Yiran lay on the sofa like a dead man, occasionally taking some food from the table—chocolate rice crackers and egg rolls. The snacks she bought in Philadelphia had really come in handy.

Alas, this ability does have side effects. Recently, Chen Yiran has noticed that she needs to go to the toilet much more often.

Chen Yiran lay there like a corpse until after 10 p.m., when he finally received feedback from Jasmine that he had finished learning.

I've finished reviewing the core framework of Lagrange duality and KKT conditions. I understand the SVM part of CS229. However, I still need to brush up on matrix calculus; CS229 involves many matrix differentiation operations, which are quite different from ordinary calculus.

"I didn't learn matrix calculus in my past life? Why do I feel like I did?"

[You have basic matrix operations in your memory, but you haven't systematically learned about matrix gradients and Hessian matrices. However, I recalled the CS229 lecture notes, which included a reference manual for matrix calculus, so you don't need to find a separate textbook.]

"Then you can just go back and look at the CS229 lecture notes."

【Hmm. With this afternoon's addition, the first half of CS229 is completely understandable. There's still neural networks and the EM algorithm to go; you're already quite tired, so let's wait until tomorrow.】

Chen Yiran decided to finish the first half first, so he opened CS229 and turned to the SVM page.

"Come on, watch it before you go to sleep."