Support

Mathtuition88.com is a Math Education Blog that aims to provide useful Math / Education content that helps people worldwide.

Over the years, Mathtuition88.com has grown to reach 500,000 total views, thanks to support of fans!

If you find our website useful, please consider supporting it in one of the following ways. Thanks!

1) Link back to our page (mathtuition88.com)

Every hyperlink counts! It could be a reblog, tweet, facebook, or a link in your blog. It doesn’t cost a cent, yet it is extremely important to the growth of the website.

2) Patreon

Our patreon page is at: https://www.patreon.com/user?u=4235868

3) Buy yourself a gift at Amazon

Purchase any item at Amazon using this link: Amazon.

4) Buy a Math Resource

Our sales page is here: https://mathtuition88.com/math-notes-worksheets-sale/

5) Advertise on our website

Our advertisement page is here: https://mathtuition88.com/sponsored-post-advertisement/

Thank you once again for your support.

Posted in math | Tagged , | Leave a comment

Math Blog

Subscribe to our free newsletter, for updates on Math, Education and other General Knowledge topics!

Enter your email address to follow this blog and receive notifications of new posts by email.

Posted in math knowledge | Tagged , | 1 Comment

LaTeX Table Style Guidelines

Drawing LaTeX tables is well known to be quite troublesome. Fortunately, there are some excellent tools online to generate LaTeX code for tables, e.g. Convert Excel to LaTeX.

Even after that, there are some stylistic dilemmas, for instance how many borders to include in the table?

I found this powerpoint slide that summarizes very nicely what to do (and what not to do) to create a nice LaTeX table. Source: https://inf.ethz.ch/personal/markusp/teaching/guides/guide-tables.pdf

Most Important Guidelines for Making Tables with LaTeX

  • Avoid vertical lines
  • Avoid “boxing up” cells, usually 3 horizontal lines are enough: above, below, and after heading (see examples in the guide above)
  • Avoid double horizontal lines
  • Enough space between rows
  • If in doubt, align left

The above 5 guidelines were invaluable and cleared up my doubts on how to make a nice table using LaTeX.

Posted in Uncategorized | Tagged , | Leave a comment

Express vs Normal Academic for borderline PSLE score

Just to share this old post on the dilemma of choosing Express vs Normal Academic (for borderline PSLE scores). Both choices have pros and cons and hence must be pondered carefully.

Singapore Maths Tuition

For students scoring in the borderline of around 190- 200 PSLE score, there is a dilemma of going to Express stream in a neighborhood school, or Normal Academic N(A) in a more established school. Note that even good schools like Anderson, ACS (Barker) do have N(A) streams.

Here are some advices from people who have experience:

Source: Hardwarezone

First opinion says that N(A) in a good school is better:

“NA in good school

i myself is living example

in the end my parent chose express at neighborhood school

in the end that school is a s**** school. i cannot keep up with studies.

by secondary 2 i drop to NA

then stuck with the lousy neighborhood school and my whole life got ruin until now

if i can go back time i sure chose NA at good school”

This post (from Hardwarezone) made a good argument of why express stream…

View original post 606 more words

Posted in Uncategorized | Leave a comment

Ways To Turn Writing Inspiration Into Money

A good writer is gifted with imagination and the ability to capture the imagination of readers. A lot of these writers begin writing as a hobby. However, some have found a way of converting this hobby into an economic activity that brings revenue. You may take up freelance writing job or engage in other activities that will pay for the effort and skill you already possess.

Image

Writers have multiple options when looking for places to apply their skills. The options will depend on personal interests, available time, and the willingness to venture into a particular field, among other factors. Here are the options available to talented writers who wish to make a few dollars from their skills. 

Blogger

Open a blog where you share regular content with followers and readers. A lot of blogging platforms have emerged online that writers can use to launch their careers. A writer may also choose social media as a starting point for his or her blogging career. 

A blogger needs to identify the perfect niche for his or her blog. It should come out of interest so that your articles are insightful to read. Choose a unique style that your readers can identify with and always look forward to reading your articles. 

Writer

Individuals, businesses, and entrepreneurs are looking for the skilled persons who can tell their stories in writing. It means that a writer will never lose the opportunity to make money. You must possess the best skills that will enable you to meet your client’s expectations. 

Choose a niche and master the content needs for the area. For instance, a product reviewer will know what potential customers are looking for in a review. A content writer also understands the rules for producing the best description of merchandise. Your prowess in a given area will determine the number of clients who come looking for your services. Expert writers earn handsome returns. 

Editor

Editing is a skill that few have mastered. It requires a professional who understands the rules of writing and has a third eye to spot subtle mistakes. Editing eliminates errors that would distort communication leading to misreporting or misinformation. Experienced writers can take up editing roles and enjoy excellent returns. 

Ghostwriter 

Some individuals and institutions lack the time or skill to write but would desire to produce scripts and books. Ghostwriters are paid to complete the task but not take credit for the work. You have to master writing skills in a specific area like blogging, books, and such other genres. 

Trainer 

A lot of people desire to improve their writing skills. They are looking for mentors and trainers who can help them sharpen their writing skills. Since you understand writing and have specialized in a particular area, you can teach other persons looking for guidance or assist them in improving their skills. 

The amount of money earned from writing prowess depends on your area of choice and the ability to monetize the platforms you use. The money can be earned online or offline. Adapt to the latest writing tricks to improve your chances of making more money. 

 

Posted in Uncategorized | Leave a comment

Singaporean van Gogh – Mr Sim Kah Lim

Sim Kah Lim 2019 Update
Found 2 more excellent updated videos on Mr Sim Kah Lim, the artist.

Singapore Maths Tuition

This is an amazing story of an amazing artist. His passion for painting is so great, according to his therapist he wants to paint 24/7 without eating or sleeping. I find his paintings of Singapore River very good.

“Bumboats on Old Singapore River”

“Singapore River of a Previous Era”

SINGAPORE: For nearly 35 years, Mr Sim Kah Lim’s world has been the walls of his ward at the Institute of Mental Health (IMH).

Outside, changes have swept the landscape, old buildings falling and new ones rising – skylines and shorelines of a 21st-century nation transformed.

But in his mind’s eye – and in his bold-stroked acrylic and watercolour paintings – Mr Sim’s homeland is one where bumboats still crowd the Singapore River, ferrying goods and passengers; and where Chinatown’s open-air markets thrive and its five-foot ways are bustling with locals, not tourists.

They are pictures, frozen in time and memory, from…

View original post 90 more words

Posted in Uncategorized | Leave a comment

Narrow Leaf Java Fern vs Normal Java Fern

It is well known that the Java Fern has different “varieties” — such as “trident”, “Windelov”, “Narrow Leaf” and “Needle Leaf”.

I kept normal Java Fern, as well as “Narrow Leaf” Java Fern in Singapore, at a temperature of around 29 to 30 degrees Celsius (85-86 Fahrenheit).

I found that the Normal Java Fern does well (nice green color, and grows baby plantlets), but the “Narrow Leaf” Java Fern does not do well (becomes browner and even blacker by the day).

I checked online and at least four other people have experienced this:

I think cooler temperatures might be the answer. My narrow leaf in syd are lush green and pearling like mad in temps of 25 celsius. In KL, 28-29 celsius, they grow a little, turn brown sometimes and are a bit of a hassle to keep. My normal java fern does well in any temps/conditions, just the narrow leaf, more demanding. Has anyone grew nice long narrow leaf in warm temps? Those in LFS have them in air conditioned rooms.

Source: http://www.aquaticquotient.com/forum/showthread.php/21779-Narrow-leaf-Java-Fern


Narrow Leaf Java Fern does better in cooler temperatures (around 25 degrees Celsius)

Other anecdotal evidence that Narrow Leaf Java Fern may do better in cooler waters:

Wes,

I’ve had a lot of success with Java Ferns and Narrow Leaf Java Ferns (NLJF) in my tank.

My tank is high-light (288Watts for 80gallon) and has lots of CO2 (3bps). I dose it with TMG almost every week. I tie the JF on driftwood and also bury them in my substrate, either way it grows well. Kwek Leong did share with me that growing them in substrate will produce longer leaves for NLJF and that holds true in my tank. I place them very new my water outlet as I read somewhere that the JF thrives in that environment. Also, I have a chiller that keeps my water temp at around 24.5-25.0C.

Hope this helps!

Cheers,

Roger

Another post:

I knew of a tank that grow Narrow Leaf Java Fern very well and the conditions are like what Roger has too. Under these conditions, they grow very rapidly and the leafs are jade green and very clean (no spots at all).

Yet another post:

I used to have prolific growth of Narrow Leaf Java Ferns in my tank. I don’t think CO2 injection is necessary but the ferns probably do better under low light and cold water.

Source: http://www.aquaticquotient.com/forum/showthread.php/49107-Best-conditions-for-Java-Fern

Methylene Blue and Narrow Leaf Java Fern

Something else interesting that I found out is that methylene blue seems to affect narrow leaf Java Fern negatively, but not normal Java Fern. Basically, the Methylene blue seems to stain the narrow leaf Java Fern, and lead to its demise. I tried this out inadvertently while dosing my fish tanks with methylene blue to cure ich.

The Narrow Leaf Java Fern is on the right of my fish tank in the video below (it was still in an ok state at that time):


I think the conclusion is that Narrow Leaf Java Fern is a slightly more demanding plant when it comes to temperature (does not do well above 27-28 Celsius). Due to global warming, many countries in the tropics are now stuck with 30 degrees Celsius temperature almost all year round, hence the normal Java Fern may be a better choice.

It also sort of makes sense in terms of plant biology. Usually plants with “thin” leaves tend to be those that live in colder/cooler weather such as pine trees. While plants with big wide leaves are those that live in hot tropical weather (such as banana tree). Using this “logic”, I would suppose that needle leaf Java Fern also does better in cooler waters.

Posted in Uncategorized | Tagged , , , | Leave a comment

How to Balance College and Work and Find Some Spare Time

No one said it would be easy, but if you’re looking for ways on how to balance college and work, use these tips to improve time management.

A recent survey revealed that the majority of students work while attending college. Learning how to balance college and work on a full-time basis is your key to achieving success with less student loan debt.

According to this survey, 24.4% of students claimed they were fully responsible for funding their education. If your dream depends on you getting a degree, please know that your goal is still within reach.

Attending school and working full-time isn’t easy, but any effort you invest in this endeavor will pay off big time. You, too, deserve to feel the pride of graduating with a degree.

Here are some tips on how to balance work and college full-time.

How to Balance College and Work: Time Management

Knowing how to balance work and college means mastering time management. Developing time management skills involves planning and budgeting your time well. When you have 2 schedules to juggle, you must keep track of both to succeed.

Make sure you either write down your work hours or mark them on your phone’s calendar. Use a college schedule maker to create a visual reminder of your class schedule.

Print several copies of this schedule, including a copy to carry with you and another copy to hang up in your workspace.

Designated Workspace Hours

Anyone who’s aware of how to balance school and work in college has a designated space where they complete their work. This space is organized, clean, and stocked with supplies. It’s also free of distractions, so getting work done is more doable there.

A designated workspace like this helps you be more productive. Once you get into the habit of doing schoolwork there, your brain starts associating that space with getting homework done. Then simply entering this workspace will kick your brain right into “homework mode.”

Carve out time that you’ll commit to spending in your workplace. During this time, you’ll study and complete homework. School is just as important as work, so you need to devote time to it.

This way, you won’t have to rush and can work on this next tip.

Sleep Schedule and “Me” Time

Make sure you maintain a regular sleep schedule. Also, try to enjoy some “me” time whenever you get the chance. Your schedule is already packed, so there’s no need to cram more stuff into your day.

Sure, caffeine will help you stay awake. But no amount of caffeine will energize you as much as a good night’s sleep can.

Work on your assignments as soon as possible instead of procrastinating. Getting work done on time reduces your need to rush or pull an all-nighter.

You Are a Success in Progress

The CDC recommends that you get at least 7 hours of sleep per 24-hour period. You can’t truly know how to balance college and work if you’re not getting enough sleep.

If you do pull an all-nighter, make sure you get sleep as soon as possible. An erratic sleep schedule will eventually hurt your work/academic performance.

Give yourself some credit⁠ and check out our resume and networking tips. It’ll improve your chances of landing a better job.

Posted in Uncategorized | 1 Comment

Bend It Like Beckham: How to Become a Pro Soccer Player

How to Become a Pro Soccer Player

Ever wanted to bend it like Beckham? Turns out, you can with the right training and dedication. Read on to learn how to become a pro soccer player.

Sure, a lot of people dream about becoming a professional athlete. But, most of them don’t have what it takes to go pro and wind up giving up on their dreams.

Becoming a pro soccer player requires a little bit more than a love for the game; it takes a lot of hard work, patience, and determination.

If you think you have what it takes to make it in the big league, but aren’t sure where to begin, we’re here to help you chart your course.

Here’s everything you need to know about how to become a professional soccer player.

Be Ready to Dedicate Yourself

If you’re serious about becoming a professional soccer player, you’re going to need to be ready to give your life over to your sport.

In the years leading up to and during your pro career, you’re going to need to eat, sleep, and breathe soccer. Your body is now your most important tool, and you’ll need to do everything you can to hone it and mold it into a soccer-playing machine.

You’ll need to put together a strict training regimen, and spend a few hours every day practicing.

Outside of training, you’ll need to change your eating and sleeping habits to make sure you’re taking proper care of your body. That means giving up late nights and junk food.

If you think you can handle molding your life around your sport, you can begin to pursue your professional career.

Join a Club or a Team

You can’t walk up to a recruiter and insist you can play at a professional level. You’re going to have to prove it. And, the best way to show off your soccer skills is by joining a local team or a club.

Playing minor league or college level soccer is one of the best ways to get noticed on the field. That said, playing university sports can pose the additional challenge of balancing classes on top of your practice time.

If you make your university’s team, you’ll want to sit down with a college schedule maker to plan your classes and study time around your soccer career.

Joining a team will also help you work on your communication and teamwork. These skills are essential when playing a professional level sport.

On top of that, a team will have the resources available to help you get in touch with club owners and recruiters.

Train On and Off the Field

If you want a chance at going pro, you’re going to need to train outside of team practices.

Work with your coach or professional trainer to construct a good crosstraining program. You’ll also want to go over the best activities you can do to help your body recover on your rest days.

Sticking to a rigorous training program can be tough. But, all your hard work will be worth it the first time you don your pro uniform.

Build Your Network

Finally, like with most careers, it’s not always about what you can do, it’s about who you know.

Go to networking events, talk to your coaches about your goals, and prepare a highlight reel to send out to various clubs and recruiters.

Building a network is one of the best ways to bring your pro soccer dreams to life.

Becoming a Pro Soccer Player

If you want to become a pro soccer player, the most important thing you can do is maintain belief in yourself and your goals.

Reaching the professional level can take years. And during that time you’re probably going to face a lot of rejection. But, if you never doubt yourself and keep working toward your goal, you’ll eventually reach it.

Are you looking for more advice on how to take your game to the next level? We’ve got you covered.

Check out the rest of our blog for more helpful articles today!

Posted in Uncategorized | Tagged | Leave a comment

Fish at Yale-NUS Eco pond

Some very interesting fish (South American cichlids?) at the Yale-NUS Eco-pond. It is quite an unknown place, located deep inside U-Town. Not many people know of its existence. Do check it out if you pass by NUS.

At around the 1:45 mark in the video, you can see some juvenile cichlids eating algae growing on the rock.

Some photos of the Yale-NUS Ecopond:

The pond is behind this large circular fountain.

 

There is also this rare tree (supposedly the only one in Singapore) right behind the pond, called “Margaritaria indica”. I think only expert botanists can tell what is so special about this tree. To laymen (like me), it looks like any ordinary tree.

Posted in Uncategorized | Tagged , , | 1 Comment

How to make work-life balance work (TED talk)

Quotes from the talk:

  • “People are working long hard hours at jobs they hate, to earn money to buy things they don’t need, to impress people they don’t like”

A book by the same speaker:


Fat, Forty, and Fired: One Man’s Frank, Funny, and Inspiring Account of Losing His Job and Finding His Life

Posted in Uncategorized | Tagged , , , | 1 Comment

Amazing method to unblock stuffy nose

Added another great way to unblock nose. This is a new method called Nasal Septum Mobilization invented by Dr Alan Mandell.

Singapore Maths Tuition

Out of all the methods I checked on YouTube, this method seems to be the most effective in terms of instantly unblocking your nose.

Basically pinch your nose and sway, until you are almost out of breath, then breath in through your nose. I find it very effective.

This method is very good also: Nasal Septum Mobilization invented by Dr Alan Mandell. It is quite a novel method, so far I have only seen it on his YouTube channel and not anywhere else. I think it may work for people with Deviated Septum as a natural remedy. Basically, the way it works is by moving the septum so as to create a “motion” to unblock the nose.

View original post

Posted in Uncategorized | Leave a comment

LaTeX Horizontal Flowchart (Workflow)

Source: https://tex.stackexchange.com/questions/368482/one-horizontal-line-flow-chart?rq=1

Just found an excellent source on how to draw a simple (slightly fanciful) horizontal flowchart using LaTeX (TikZ).

The output is very neat:

The code is reproduced here (in case the original source gets deleted):

\documentclass[tikz, margin=3mm]{standalone}
\usetikzlibrary{arrows.meta,
                chains,
                positioning,
                shapes.geometric
                }
% for fancy looks of data storages
\begin{document}
    \begin{tikzpicture}[
    node distance = 5mm and 7mm,
      start chain = going right,
 disc/.style = {shape=cylinder, draw, shape aspect=0.3,
                shape border rotate=90,
                text width=17mm, align=center, font=\linespread{0.8}\selectfont},
  mdl/.style = {shape=ellipse, aspect=2.2, draw},
  alg/.style = {draw, align=center, font=\linespread{0.8}\selectfont}
                    ]
    \begin{scope}[every node/.append style={on chain, join=by -Stealth}]
\node (n1) [disc] {Training\\ data};
\node (n2) [alg]  {Learning\\ algorithm};
\node (n3) [mdl]  {Model};
\node (n4) [disc] {Test\\ data};
\node (n3) [mdl]  {Accuracy};
    \end{scope}
\node[below=of n2]  {Step 1: Training};
\node[below=of n4]  {Step 2: Tresting};
    \end{tikzpicture}
\end{document}
Posted in Uncategorized | Tagged , , , | Leave a comment

Chinese Tutor (has experience in tutoring NYGH/RGS/RI students)

Singapore Maths Tuition

Chinese Tuition Singapore
新加坡华文补习老师
Tutor: Ms Gao (高老师)

Ms Gao is a patient tutor, and also effectively bilingual in both Chinese and English.

A native speaker of Mandarin, she speaks clearly with perfect accent and pronunciation. She is also well-versed in Chinese history, idioms and proverbs.

Ms Gao is able to teach Chinese at the Secondary school level (Chinese and Higher Chinese). She will teach in an exam-oriented style, but will also try her best to make the lesson interesting for the student.

Ms Gao has taught students from: Nanyang Girls’ High (NYGH), RGS, RI, and other schools.

Contact:

HP: 98348087

Email: chinesetuition88@gmail.com

Website : https://chinesetuition88.com/
(Preferably looking for students staying in the West side of Singapore)

View original post

Posted in Uncategorized | Leave a comment

Amazing method to unblock stuffy nose

Out of all the methods I checked on YouTube, this method seems to be the most effective in terms of instantly unblocking your nose.

Basically pinch your nose and sway, until you are almost out of breath, then breath in through your nose. I find it very effective.

This method is very good also: Nasal Septum Mobilization invented by Dr Alan Mandell. It is quite a novel method, so far I have only seen it on his YouTube channel and not anywhere else. I think it may work for people with Deviated Septum as a natural remedy. Basically, the way it works is by moving the septum so as to create a “motion” to unblock the nose.

Posted in Uncategorized | Tagged , , | 1 Comment

Cai Yun Zhui Yue Piano Sheet Music (PDF)

This is a classical piano tune that is masterfully transcribed (by arranger Wang Jianzhong 王建中). In English, it is also called “Colourful Clouds Chasing the Moon”. In Chinese, it is called 彩云追月.

The transcription is really very nice, the harmony and the melody of the original tune is preserved and even enhanced. Few piano scores for Chinese music can achieve this effect.

The sheet music (or piano score) is originally from http://www.everyonepiano.com, we simply convert to PDF for the convenience of those who are seeking it:

PDF Sheet Music Score for Cai Yun Zhui Yue: Cai Yun Zhui Yue PDF

I checked that this version is the same as the one performed by Li Yundi:

Posted in Uncategorized | Tagged , , | Leave a comment

Taiwan Aquarium Fish Tour

There are many blogs focusing on Taiwan tourism, this blog focuses on the aspect of fish you can see/eat in Taiwan.

Koi at Chiang Kai-Shek Memorial Hall

If you visit the Chiang Kai-Shek memorial hall in Taipei, do check out the pond just nearby. There are many koi in the pond, and also a vending machine with fish food for sale (around NT$10 for a tube of fish food). There are various colors of koi, ranging from dull gray to colorful red, white or gold colors.

Marimo Moss Ball Exhibition at National Taiwan Museum

The National Taiwan Museum is not as famous as the other museum, National Palace Museum (aka Gu Gong), but nonetheless it holds some interesting specimens related to Taiwan. When I went there, there was a small Marimo Moss ball exhibition. The Marimo Moss ball were of exceptional high quality (better than any moss ball I saw in Singapore). They were dark green, dense, and almost perfectly spherical.

Water Lettuce Bowl with Guppy

Very healthy looking Water Lettuce specimens in a large porcelain bowl. The leaves were almost perfect, with no holes. There is also a female guppy (camouflaged in the second picture), together with guppy fry living in the bowl. This was seen on Shifen Old Street towards the waterfall.

Koi Pond en route to Shifen Waterfall

On the way to the famous waterfall at Shifen, there is yet another Koi pond with the option to purchase fish food (this time at NT$20). Interestingly, I did spot fishes in the river adjoining the waterfall, but it is quite hard to photograph them due to their color (dull black) and the distance. I wonder what happens if they fall down the waterfall.

Aquarium Shops in Taipei

The most famous aquarium street in Taipei is the one at Section 5, Minquan East Road. Unfortunately, it is not very accessible via train. Despite sounding similar, the Minquan West Road Metro station is very far from Minquan East Road.

I went to a nearby aquarium in Shilin district instead. To my surprise, there was an alligator snapping turtle in the aquarium (together with various interesting species of aquatic tortoises). Just beside the aquarium was a local Taiwanese restaurant popular with locals, with free flow rice and ice-cream. In the restaurant, there are a few live fish and crabs for eating, and there was a moray eel inside!

One thing to note is that Cod Fish (Snow Fish or Xue Yu) is quite cheap in Taiwan, in the restaurant one slab of Cod Fish the size of my hand is just NT$180 or SGD$8. In Singapore, the price is at least double or triple that.

Posted in Uncategorized | Tagged , , , | Leave a comment

pip install keeps installing old/outdated packages

This article is suitable for solving the following few problems:

  1. module ‘sklearn.tree’ has no attribute ‘plot_tree’
  2. pip install (on Spyder, Anaconda Prompt, etc.) does not install the latest package.

The leading reason for “module ‘sklearn.tree’ has no attribute ‘plot_tree” is because the sklearn package is outdated.

Sometimes “pip install scikit-learn” simply does not update the sklearn package to the latest version. Type “print(sklearn.__version__)” to get the version of sklearn on your machine, it should be at least 0.21.

The solution is to force pip to install the latest package:

pip install --no-cache-dir --upgrade <package>

In this case, we would replace <package>  by “scikit-learn”.


Sometimes, pip install does not work in the Spyder IPython console, it displays an error to the effect that you should install “outside the IPython console”. This is not normal (i.e. it should not happen), but as a quick fix you can try “pip install” in Anaconda Prompt instead. It is likely that something wrong went on during the installation of Anaconda, Python, and the long-term solution is to reinstall Anaconda.

Posted in Uncategorized | Tagged , , | Leave a comment

caret package in R: known issue when converting factor variables

In the R language, often you have to convert variables to “factor” or “categorical”. There is a known issue in the ‘caret’ library that may cause errors when you do that in a certain way.

The correct way to convert variables to ‘factor’ is:

trainset$Churn = as.factor(trainset$Churn)

In particular, “the train() function in caret does not handle factor variables well” when you convert to factors using other methods.
(See https://rpubs.com/SulmanKhan/444033)

Basically, if you use other ways to convert to ‘factor’, the code may still run, but there may be some ‘weird’ issues that leads to inaccurate predictions (for instance if you are doing logistic regression, decision trees, etc.)

Posted in Uncategorized | Tagged , , | Leave a comment

Saving Rasbora from Dropsy

Recently, my mosquito rasbora (Boraras merah) was acting weirdly by hiding in a corner and sleeping more than usual.

Upon closer examination, I found “specks” on it. At first I thought it was velvet. However, this was an old tank and there has not been any introduced fish for more than 2 months. Then I realized it was probably dropsy and the specks were actually pineconing of the scales, which looks like specks of dust because of the smallness of the scales (this mosquito rasbora is one of the smallest fish in the freshwater aquarium, measuring less than 2 cm when fully grown). In conclusion, I think dropsy in tiny fish can probably look like velvet.

I think the reason is that the dwarf hairgrass (and Japanese hairgrass) planted in the sand substrate has failed to grow, and in fact has started to die and rot, releasing ammonia, nitrites and/or nitrates into the water. I do have a Seachem Ammonia Alert badge that did not show any readings.

Hence, I suspect it is probably nitrates. I added Methylene blue (full dose) after 50% water change, and then continued 50% water change on the second day, topping up the Methylene blue (half dose). On the third day, another 50% water change. (For all days during the water change, I removed the rotting hairgrass as well as any pond snails pests that I find, and wiped off algae).

After the third day, the mosquito rasbora began to behave normally again, swimming around and schooling together with the lambchop rasbora. I hope it will survive.

The lambchop rasbora seem unaffected and seem more hardy than the mosquito rasbora. I think the mosquito rasbora may be more sensitive to water parameters.

Mosquito Rasbora in (diluted) Methylene Blue water.

Posted in Uncategorized | Tagged , , | Leave a comment

Philips Stainless Steel Pressure Cooker

The keyword here is “stainless steel”, because if you look at many pressure cookers, the inner pot is made of aluminum alloy. The bad thing about aluminum is that it is linked to Alzheimer’s disease. For instance, this medical paper states that “Immediate steps should be taken to lessen human exposure to Al (aluminum), which may be the single most aggravating and avoidable factor related to AD (Alzheimer’s disease).”

Philips makes one of the best brands of pressure cookers, including the famous HD2137 model which is sold in Singapore. It can be bought almost anywhere, including the Philips Qoo10 official store:

[S$147.00](▼64%)[PHILIPS]PHILIPS HD2137/62 Viva Collection All-in-One Cooker | HD2139/62 Pressure Cooker

WWW.QOO10.SG

The default Philips pressure cooker, however, comes with aluminum inner pot, no matter which model. Fortunately, there is a solution, which is to buy the Stainless Steel Inner Pot from the official Philips website.

Highly recommended to upgrade to this stainless steel inner pot.

The stainless steel inner pot is suitable for the following models: HD2137, HD2237, HD2178, HD2145. It is quite pricey at $59 (Singapore dollars), but I think it is worth it considering that it should last for a lifetime or at least a long time.

Interestingly, Philips sells these pressure cooker models mainly to Asian market. I don’t find them in the American Amazon.com website. Perhaps the American diet (steak, burgers, fries) don’t really require the pressure cooker? I am not sure.


Do check out some of the amazing recipes possible using the Philips Pressure Cooker with Stainless Steel Inner pot:

Posted in Uncategorized | Tagged , , , | Leave a comment

How to save sklearn tree plot as file (Vector Graphics)

The Scikit-Learn (sklearn) Python package has a nice function sklearn.tree.plot_tree to plot (decision) trees. The documentation is found here.

However, the default plot just by using the command

tree.plot_tree(clf)

could be low resolution if you try to save it from a IDE like Spyder.

The solution is to first import matplotlib.pyplot:

import matplotlib.pyplot as plt

Then, the following code will allow you to save the sklearn tree as .eps (or you could change the format accordingly):

plt.figure()
tree.plot_tree(clf,filled=True)  
plt.savefig('tree.eps',format='eps',bbox_inches = "tight")

To elaborate, clf is your Decision Tree classifier (to be defined before plotting the tree):

# Example from https://scikit-learn.org/stable/modules/generated/sklearn.tree.plot_tree.html
clf = tree.DecisionTreeClassifier(random_state=0)
clf = clf.fit(iris.data, iris.target)

The outcome is a Vector Graphics format (.eps) tree that will retain its full resolution when zoomed in. The bbox_inches=”tight” command prevents truncating of the image. Without that command, sometimes the sklearn tree will just be cropped off and be incomplete.

Posted in Uncategorized | Tagged , , | 1 Comment

In the northern darkness there is a fish and his name is K’un.

Just realized that there is some parallel between the Chinese Giant Fish Kun (鲲) and the Jewish Giant Fish Leviathan.

Similarly, Chinese Giant Bird Peng (鹏) = Jewish Giant Bird Ziz.

In the northern darkness there is a fish and his name is K’un. The K’un is so huge I don’t know how many thousand li he measures. He changes and becomes a bird whose name is P’eng. The back of the P’eng measures I don’t know how many thousand li across and, when he rises up and flies off, his wings are like clouds all over the sky. When the sea begins to move, this bird sets off for the southern darkness, which is the Lake of Heaven.

Source: https://en.wikipedia.org/wiki/Peng_(mythology)

As Leviathan is the king of fishes, so the Ziz is appointed to rule over the birds. His name comes from the variety of tastes his flesh has; it tastes like this, zeh, and like that, zeh. The Ziz is as monstrous of size as Leviathan himself. His ankles rest on the earth, and his head reaches to the very sky.

Source: https://en.wikipedia.org/wiki/Ziz

Clockwise from left: Behemoth (on earth), Ziz (in sky), and Leviathan (under sea). From Wikipedia.

Cool picture of Giant Fish Kun from Baidu.

Posted in Uncategorized | Tagged , , | Leave a comment

Singtel Dash Cashback Promo

Singtel Dash Promo Code:

Hi! Get up to $2 cashback when you make your 1st  transaction via Singtel Dash! Sign up with this link now –

https://appserver.dash.com.sg:443/mgm?DASH-2I2KM .T&Cs apply. 

Posted in Uncategorized | Leave a comment

6 Things All Mathematicians Do

It can be hard when your child is struggling academically. When kids feel defeated they tend to push against the homework they’ve been assigned and before you know it everyone is upset and they keep falling further and further behind. And then comes the famous phrase “I’m never going to need to know this, anyway!” 

And sure, that may be true. But that doesn’t necessarily mean it isn’t worth learning. With the help of math tutors in Chicago or your area, you can get your child back on track and help them to not only find success in school but apply the skills they’ve learned to other areas of their life. 

Everyone is a mathematician! Seriously! Take a look at this list of things that mathematicians (you) do and consider how it will benefit your child in their life to learn all that math has to offer. The benefits of learning math certainly outweigh the fact they might not like it right now. 

1. Math Makes You A Problem Solver

Math is all about the analytical mindset and being experienced in math allows us to think critically and to reason. It seems weird to think about how a train leaving a station problem can truly affect our mindset, but when you learn to solve math problems you will exercise the same skills you will need to solve other problems. 

Problem-solving is all about taking the knowns and unknowns and implementing a process to make the best possible choice. Math exercises the brain and allows you to apply mathematical strategies to everyday life. Getting kids excited to be problem solvers isn’t hard, they come by it naturally. Help them engage them in math and they will succeed!

2. Cooking and Baking? All Math!

Think about the process of making pancakes on Saturday morning. There’s so much math going on that maybe you don’t even recognize. You have to measure ingredients and figure out how many pancakes each person is going to get. Maybe you need to double your recipe? It’s likely you don’t sit down to think about how to change the quantities of ingredients. 

The fractions and math needed in cooking and baking are just one real-world application of math skills and it’s also a great way to engage your child in the learning process. Having a reluctant learner learn fractions by baking cookies is a great option with a sweet reward. 

3. Math Helps Your Career

Sure, the adult world seems far away for your nine-year-old but the skills she is learning today will inevitably aid her career path. Math is used in almost every career somehow. Obviously mathematicians and scientists and doctors rely on math frequently. Whether or not you plan to utilize higher-level math on a regular basis you have to admit everyone uses math sometimes.

Imagine you’re driving on a road trip. Figuring out gas, mileage, and speed is all math and that’s stripping it down to the basics. Math is everywhere, even without you realizing it. Fostering math education is important for your child’s future. 

4. Money Is Math.

When you explain it to a child that way, they may suddenly get a lot more eager to figure out the math they’re struggling with. Even automated cash registers require some knowledge of basic arithmetic. Consider opening a savings account in your child’s name to spark their interest beyond what the tooth fairy is bringing. 

Even if your child is absolutely certain she will never use math, it’s worth mentioning she will eventually have to get a job and get paid. Understanding her take-home pay versus taxes and exemptions is a crucial part of financial planning and responsibility. In these basic terms, everyone uses math.

People who know math are less likely to go into debt because they are able to understand their account balances and can budget them correctly. Nobody likes overdraft fees but if you’re not mathematically conscious they’re far more likely to occur. When you teach a child the basics they will be able to be far more self-sufficient in the future.

5. No Matter Where You Go, Math is the Same!

One of the most interesting things about math is that it’s universal. All over the world, all  children learn the same math. Mathematical rules don’t change because you’re in another country — 1 + 1 = 2 no matter where you are. 

Understanding this concept early broadens your worldview and can inspire children to learn. Math can actually be a joyful concept when you add some perspective to a child’s education. It is often reassuring to children that there are others in the same situation as they are.

6. Technology Relies on Math

You know that smartphone your teenager just has to have? It runs because of math. Math is essential to learning new technologies. In today’s world technology is changing as we speak. Children today need to learn math so that they can keep up and helped create the next latest technological advancement. 

If you believe that children are our future you should also believe that math skills are an integral part of that future. So when your teenager gets frustrated that his app keeps crashing, explain that he could use his math skills to create an app of his own. 

Conclusion: 

It’s never too late to increase your brain’s capacity for learning math. It may take a little more work but you can always inspire your children to continue on their math education. When it seems like an uphill battle, it’s a great idea to bring in some outside help from a tutor. 

A solid mathematical education is essential for children no matter what their passions and ambitions are. Everyone uses math! It’s just a matter of finding the right way to get your child excited about it as well. Sure, Algebra may seem complicated but if they can conquer that they are on their way to being able to conquer anything at all.

Posted in Uncategorized | 1 Comment

Domain Authority 30

Previously, Page Rank was the more appropriate ranking system for how well a page or domain ranks on Google. However, Google has since temporarily (or permanently?) discontinued Page Rank.

Hence, now the closest measure to Page Rank is Domain Authority, by the company Moz.

Currently, Mathtuition88 has Domain Authority 30. Domain Authority is on a logarithmic scale, meaning that it is harder to increase from 80 to 90 than from 30 to 40.

According to the Moz forum, the Head Data Scientist said that a formula to convert to linear scale from the logarithm scale is:

If you just want an estimate, take the log (base 10). You’ll get a value from zero to two that will be roughly linear, and then you can scale it up to whatever range you need.

To be specific, a formula to convert Moz scale to “normal non-logarithmic scale” out of 100 is:

New Score = log(DA) * 50

Using this formula, the score for Mathtuition88 is log(30)*50 = 73.9.

Actually, I am a little skeptical about the above formula and how accurate it is. For instance, I think that one should take exponential (to the correct base) instead of log again for the “non-logarithmic” scale?

For instance,

log(40)* 50 = 80.1

log(80)*50 = 95.2

log(90)*50 = 97.7

Hence, to increase from DA 30 to DA 40 corresponds to an increase in “New Score” of 6.2. To increase from DA 80 to DA 90 corresponds to an increase in “New Score” of 2.5. This does not tally with the idea of “it is harder to increase from 80 to 90 than from 30 to 40”.

Another quote from Moz:

Dr. Matt Peters, Moz’s head of Data Science:

“PA and DA are the output from a machine learning model that we then rescale to values between 1-100.  The raw output from the model is dimensionless and doesn’t have any interesting meaning.  The rescaling is linear, but the inputs to the model are rescaled logarithmically before being used in the model.  We use the natural log (base e) but the base is pretty arbitrary since one can transform from one base to another by changing coefficients, and the coefficients themselves are set in a regression.  The key point is that since the inputs have a log applied to them it is much harder to increase DA from say 70 to 80 then it is from 30 to 40.”

Based on this, another formula to convert Moz’s Domain Authority to a Non-logarithmic score could be:

New Score = [e^(DA)/e^100)] * (100)?

The problem with the above formula is that it gives very low scores close to 0.

Mathtuition88’s Domain Authority:

MOZDomain Authority30

Posted in Uncategorized | Tagged , , , | Leave a comment

【纪录片】《统一与兴盛》,中国最棒的历史类纪录片

Probably the best documentary on China’s history to be found on YouTube.

Posted in Uncategorized | Tagged , | Leave a comment

Recommended Air Purifier for Haze

Recently the Haze in Singapore is getting worse. One can literally smell the burning smell in the air.

A recommended cheap and good air purifier for home usage is the Xiaomi Air purifier. Xiaomi is well-known for producing high-tech goods at affordable prices. For instance, their weighing scale and fitness band (Mi Band) is top-notch for their price range.

[S$169.00](▼30%)[Local Warranty] XIAOMI Air Purifier Gen 3 // 2S // Pro (Ship by 25th Sep)

WWW.QOO10.SG

Posted in Uncategorized | Tagged , | Leave a comment

Where to park your car, according to math

Math Online Tom Circle

This “Simple Car Parking” is the Decision Making Strategy demonstrated in our daily life, even in the micro-cell biological level in nature.

In the current USA-China Trade War, China Xi is taking the Prudent (中庸) approach of a partial 80% deal, while Trump is too Optimistic (or gung-ho) , insisting to accept either a “Full 100%” deal or None. Math tells you the smartest man’s approach is China Xi “Prudent” strategy.

Opportunity Score:

Meek : 1/5 score = ‘Kiasu’ (怕输 )

Prudent : 3/5 score = (中庸 )

Optimist : 5/5 or 0/5 score = (Gung-Ho)

Differential Equation:

https://m.phys.org/news/2019-09-car-math.html

In 三国演义 Three Kingdoms, the smartest military strategist Zhuge Liang (诸葛亮) was attacking the biggest northern enemy Wei (魏). He chose the Prudent (‘P’) route longer distance but less ambushes, rejected his General 魏延 ‘s Optimistic (‘O ‘) approach of taking the risky “子午谷” mountainous but shortest route.

View original post

Posted in Uncategorized | Leave a comment

Chen Jingrun–Do You Really Know About the Giant (1)

Quantum Han's Forum

This time, let’s talk about math; exactly speaking, a mathematician.

My favorite things in this world are math and physics. Today, I cannot wait to share with you some stories of Chen Jingrun, considered by many to be one of the greatest Chinese mathematicians.

th

What makes me a little outraged is that most people, including many Chinese people, who have heard of his name, think of him as a nerd who knows nothing except math. Why do people think like that? I have been wondering about this and learning about his stories, and I still cannot discover the cause. Perhaps because of the distortion of some of his stories during the Cultural Revolution? Probably most people cannot understand why a person can be so passionate, enduring, persistent, patient, frugal, and kind. Probably they cannot understand what motivated him to dedicate his whole lifetime to only one conundrum-The Goldbach Conjecture, one…

View original post 1,176 more words

Posted in Uncategorized | Leave a comment

Chen Jingrun–Do You Really Know About the Giant? (2)

Quantum Han's Forum

“Each work of Mr. Chen Jingrun seems as if it is scaling the tallest mountains of the Himalayas. It is perilous [work], but if successful, will certainly affect the world.” (André Weil, Wolf Prize in Mathematics Laureate, 1979)

It is said that numerous ambitious youths have been inspired, spurred by Chen’s virtues and respectable spirits. Somebody said that to some extent, besides proving the “1+2” case of the Goldbach Conjecture, another contribution Dr. Chen made to mankind is that his stories invigorated countless young people striving for their futures and pushed a whole generation of mathematicians and scientists forward.

u=365122135,1310335696&amp;fm=23&amp;gp=0.jpg

Dr. Chen was born into a poor family, into an era when warfare has turned China into Les Miserables. His mother did not have breast milk and borrowed rice soup from their neighbors to feed the young Chen Jingrun so that he would not starve to death. He had to shoulder…

View original post 1,820 more words

Posted in Uncategorized | Leave a comment

Chen Jingrun Biography Video

Posted in Uncategorized | Leave a comment

Time, Energy, Money at different phases of life

Hmm… Sad but true?

Source: Pinterest

Posted in Uncategorized | Tagged , | 1 Comment

Singapore Haze & Subgroup of Smallest Prime Index

Singapore Maths Tuition

Recently, the Singapore Haze is getting quite bad, crossing the 200 PSI Mark on several occasions. Do consider purchasing a Air Purifier, or some N95 Masks, as the haze problem is probably staying for at least a month. Personally, I use Nasal Irrigation (Neilmed Sinus Rinse), which has tremendously helped my nose during this haze period. It can help clear out dust and mucus trapped in the nose.

[S$89.90][Clean Air]2015 Air Purifier Singapore brand and 1 year warranty with HEPA Activated Carbon UV-C germicidal killer lamp silent operation and high efficiency etc

WWW.QOO10.SG

[S$19.90]Haze Prevention~ Nasal Rinse™- Flush out mucous~germs~bacteria~and dirt internally. Clear blocked nose and very soothing.

WWW.QOO10.SG

Previously, we proved that any subgroup of index 2 is normal. It turns out that there is a generalisation of this theorem. Let $latex p$ be the smallest prime divisor of a group $latex G$. Then, any subgroup $latex Hleq…

View original post 178 more words

Posted in Uncategorized | Leave a comment

Group of order 56 is not simple + Affordable Air Purifier

Singapore Maths Tuition

Haze strikes Singapore again, this time it is quite serious as the PSI is often above 300. For those seeking an affordable air purifier, do consider this air purifier which is one of the few that costs below $100. It is definitely reusable next year as the haze problem is not going to be solved in the near future.

[S$89.90][Clean Air]2015 Air Purifier Singapore brand and 1 year warranty with HEPA Activated Carbon UV-C germicidal killer lamp silent operation and high efficiency etc

WWW.QOO10.SG

Let G be a group of order 56. Show that G is not simple.

Proof:

We will use Sylow’s Theorem to show that either the 2-Sylow subgroup or 7-Sylow subgroup is normal.

$latex |G|=2^3cdot 7$

By Sylow’s Theorem $latex n_2mid 7, n_2equiv 1pmod 2$. Thus $latex n_2=1,7$.

Also, $latex n_7mid 8, n_7equiv 1pmod 7$. Therefore $latex n_7=1, 8$.

If $latex n_2=1$ or $latex n_7=1$, we are done…

View original post 54 more words

Posted in Uncategorized | Leave a comment

Haze affects Wifi Speed?

Recently, Singapore is plagued by the haze, arising from forest fires in Indonesia. This is a common occurrence that happens yearly.

Simultaneously, I noticed a drop in Wifi speed both at home and at work.

Is this a coincidence? Or could the haze particles be actually blocking/absorbing Wifi signals so that the Wifi is slowed down?

What do you think? Probably the same effect occurs for smog or fog.

It is well-known and established that rain affects Wifi. Hence, perhaps it is not too far-fetched to postulate that the haze affects Wifi too?

Posted in Uncategorized | Tagged , | Leave a comment

Advanced Excel Date Editing and Formatting

Suppose you have an Excel file with dates in the format DD/MM/YYYY.

So you have entries like 02/03/1999 (2 March 1999). Suppose you want to change it to 2/3/1999, i.e. remove leading zeroes from one digit days and months.

It sounds easy, but it is actually quite tricky to do it in Excel without knowledge of the correct method. The normal methods of date formatting will simply not work.

After some searching, I found and tested that the following method is probably the fastest and easiest way to do it:

Select the date column and then click Data > Text to Columns Next, Next, then select Date ‘MDY’

then you should be able to do this using a number format of m/dd/yyyy or m/d/yyyy if you don’t want a leading zero in the days as well

Source: StackOverflow

Posted in Uncategorized | Tagged , | 1 Comment

How to Score Good Marks in Class 11 Mathematics?

Mathematics is a high scoring subject in class 11 among all the subjects.  Mathematics plays an essential role for all the students to get admission in the best engineering colleges. Even though the students have prepared the problem many times, sometimes they are not confident enough while writing the examinations. Here, the list of topics and concepts in class 11 mathematics such as finding the sides of a triangle using  Pythagoras theorem in trigonometry, limits and derivatives, probability and so on are provided.

Sets – Students are suggested to practice as many questions as possible. Learn the definitions properly and draw the Venn diagram if required to score good marks.

Relations and Functions – Domain and range are the essential concepts in this chapter. Learn all the graphs of the functions given in the section “some functions and their graphs.”

Trigonometric Functions – Learn all the trigonometry formulas. This chapter contributes to prominent importance among all the sections. Also, learn the trigonometric ratios of standard angles, and trigonometric identities with its proof.

Principle of Mathematical Induction – Most of the students find this chapter exciting; you need to analyse the question from the section. One problem will come from this chapter.

Complex Numbers and Quadratic Equations – This chapter is one of the easiest chapters in class 11 mathematics as it requires only less time to prepare for the exam. Inevitably the questions are asked from the concepts such as polar representation and quadratic equations with complex roots.

Binomial Theorem – Go through the questions from “General and Middle Term of a Binomial Expansions”. The calculation errors are likely to happen in this chapter.

Permutation and Combination – Learn the definition of permutation concepts when all the objects are distinct or not distinct, and determine the combination of the given problem.

Linear Inequalities – This part needs more practice to work with the system of linear inequalities in one variable and two variables.

Sequences and Series – Since all the topics in this chapter are almost related to each other. You cannot skip any exercise. Master all the formulas in this chapter to score more.

Straight Lines – Read all the straight lines formulas. Use proper labelling, figures in the problem that should be clean and neat.

Conic Sections – Practice all the concept in this chapter. Go through the concepts such as a parabola, hyperbola, circles, and an ellipse.

Introduction to Three-Dimensional Geometry – Determine how to find the distance between two points in the 3D space and also study the section formula.

Limits and Derivatives – The essential concepts in this chapter are product rule and quotient rule. Find the derivative of a function and determine how to apply the limits of a polynomial, trigonometric and rational functions. Use trigonometry table to find the corresponding value for the trigonometric derivative function.

Mathematical Reasoning – This chapter does not require computations. Get the description of the statement and examine its validity.

Statistics – Read the formulas like mean, variance, standard deviation, and coefficient of variation of a continuous frequency distribution.

Probability – Go through all the topics in this chapter. Understand the contrast between “with replacement” and “without replacement.”

Subscribe to BYJU’S YouTube channel to discover various concepts in class 11 mathematics.

https://www.youtube.com/watch?v=z8deq-zdaIg

Posted in Uncategorized | Leave a comment

Excellent video on Bishop/Vienna Opening

Bishop’s opening is an excellent opening for White, that is not very well known. It has some dangerous traps like the video below.

Posted in Uncategorized | Tagged | Leave a comment

My Neon Tetra 5 Gallon Planted Tank

Posted in Uncategorized | Tagged , | Leave a comment

Calculate Cronbach Alpha using Python

R has the package “psych” which allows one to calculate the Cronbach’s alpha very easily just by one line:

psych::alpha(your_data, column_list)

For Python, the situation is more tricky since there does not seem to exist any package for calculating Cronbach’s alpha. Fortunately, the formula is not very complicated and it can be calculated in a few lines.

An existing code can be found on StackOverflow, but it has some small “bugs”. The corrected version is:

def CronbachAlpha(itemscores):
    itemscores = np.asarray(itemscores)
    itemvars = itemscores.var(axis=0, ddof=1)
    tscores = itemscores.sum(axis=1)
    nitems = itemscores.shape[1]

    return (nitems / (nitems-1)) * (1 - (itemvars.sum() / tscores.var(ddof=1)))

The input “itemscores” can be your Pandas DataFrame or any numpy array. (Note that this method requires you to “import numpy as np”).

Posted in Uncategorized | Tagged , , | Leave a comment

Python code for PCA Rotation “varimax” matrix

The R programming language has an excellent package “psych” that Python has no real equivalent of.

For example, R can do the following code using the principal() function:

principal(r=dat, nfactors=num_pcs, rotate="varimax")

to return the “rotation matrix” in principal component analysis based on the data “dat” and the number of principal components “num_pcs”, using the “varimax” method.

The closest equivalent in Python is to first use the factor_analyzer package:

from factor_analyzer import FactorAnalyzer

Then, we use the following code to get the “rotation matrix”:

fa = FactorAnalyzer(n_factors=3, method='principal', rotation="varimax")
fa.fit(dat)
print(fa.loadings_.round(2))
Posted in Uncategorized | Tagged , , | Leave a comment

Epsom Salt Treatment for Main Tank Dosage

The recommended dosage seems to be:

1/8 flat teaspoon (around 0.5 ml) per 5 US gallon within aquarium (long term)

1 flat tablespoon (around 15 ml) per gallon for 10 minute bath (short term)

Epsom salts can be used to cure dropsy, bloating and internal parasites in fish.

Source:

Posted in Uncategorized | Tagged , | Leave a comment

Hướng dẫn đầy đủ về VPN tại Trung Quốc

Cách truy cập Gmail, YouTube, Facebook, WhatsApp tại Trung Quốc

Điều nổi tiếng là một số trang web thiết yếu bị chặn ở Trung Quốc:

  • Toàn bộ bộ sản phẩm của Google. Điều này bao gồm Gmail, tìm kiếm Google, YouTube, Google Drive, Google Scholar, v.v.
  • Toàn bộ bộ sản phẩm của Facebook. Điều này cũng bao gồm WhatsApp vì nó thuộc sở hữu của Facebook.
  • Hầu hết các phương tiện truyền thông xã hội khác của Western Western, như Twitter.
  • Hầu hết các trang blog, bao gồm WordPress.com, Blogger.com. Điều này bao gồm không chỉ các trang đăng nhập mà còn tất cả các trang web được tạo bởi WordPress.com, Blogger.com, v.v.
  • Hầu hết các trang web chia sẻ tệp, chẳng hạn như Dropbox.
  • Wikipedia

Như bạn có thể thấy, Great Firewall của Trung Quốc chặn nhiều dịch vụ thiết yếu sẽ gây bất tiện cho hầu hết mọi người, cho dù bạn là một doanh nhân, sinh viên hay chỉ là một khách du lịch bình thường. Nó đã trở nên tồi tệ hơn trong những năm gần đây (2019 trở đi) khi Tường lửa đã mạnh hơn rất nhiều và nhiều VPN không hoạt động tốt như chúng đã làm.

Trong hướng dẫn toàn diện này, chúng tôi sẽ đề cập đến nhiều tùy chọn (VPN và hơn thế nữa) sẽ giúp bạn vượt qua Bức tường lửa vĩ đại của Trung Quốc và kết nối với Google, YouTube, Facebook, et cetera. Chúng tôi bao gồm các dịch vụ miễn phí cũng như trả phí, cũng như các giải pháp không phải VPN.

*** Rất quan trọng: Tất cả các VPN là miễn phí hoặc trả phí phải được tải xuống và thiết lập trước khi bạn vào Trung Quốc. Khi bạn vào Trung Quốc, bạn không thể tải xuống hoặc thiết lập tài khoản trên VPN.


VPN miễn phí

Hầu hết các trang web không cho bạn biết về VPN miễn phí vì chúng không nhận được lợi ích (hoa hồng) từ việc này. Chúng tôi sẽ chỉ đề xuất các VPN miễn phí đáng tin cậy, đáng tin cậy ở đây. Xin lưu ý rằng có tồn tại một số VPN VPN miễn phí mờ ám có khả năng đánh cắp hoặc rò rỉ dữ liệu của bạn. Các VPN miễn phí dưới đây không yêu cầu bất kỳ dữ liệu thẻ tín dụng nào.

*** Quan trọng: Nếu bạn chỉ dựa vào VPN miễn phí, bạn nên tải xuống và thiết lập 2 hoặc 3 lựa chọn thay thế. Điều này là do VPN miễn phí thường kém ổn định hơn và dễ bị chặn hơn vì có ít vị trí máy chủ hơn.

Windscribe Đánh giá VPN miễn phí

Một VPN miễn phí rất tốt từ một công ty chuyên nghiệp thực sự. Bạn nhận được khoảng 10 GB băng thông dữ liệu miễn phí đặt lại mỗi tháng, có khả năng nhận được nhiều hơn bằng cách tweet hoặc giới thiệu với bạn bè của bạn.

Đăng ký 10 GB miễn phí với tiềm năng để nhận được nhiều hơn chỉ bằng cách Tweet trên Twitter.

Cá nhân tôi đã dùng thử phiên bản miễn phí của Windscribe ở các thành phố khác nhau ở Trung Quốc và nó hoạt động (hầu hết thời gian). Đừng mong đợi kết nối hoàn hảo mặc dù. Nếu bạn quyết định sử dụng Free Windscribe, hãy đăng ký tại đây tại trang web chính thức của Windscribe.

Xem lại miễn phí

TunnelBear cũng cung cấp gói miễn phí (500 MB hàng tháng) không yêu cầu bất kỳ thông tin thẻ tín dụng nào từ bạn. Dựa trên kinh nghiệm của tôi, Windscribe Free tốt hơn so với TunnelBear miễn phí (dựa trên cơ hội kết nối và số lượng vị trí máy chủ). Tuy nhiên, điều đó đang được nói, rất có thể xảy ra rằng tại bất kỳ thời điểm nào, TunnelBear có thể kết nối trong khi Windscribe không thể. Do đó, khuyến nghị là nhận cả Free Windscribe và TunnelBear.

Đánh giá miễn phí Lantern VPN

Lantern VPN là duy nhất theo nghĩa nó không phải là VPN, mà là một công cụ chia sẻ mạng ngang hàng trên mạng. Vì nó hoạt động khác với VPN, nên có thể nó không bị chặn trong khi các VPN khác. Lantern có tùy chọn Miễn phí (URL: https://getlantern.org/) cho phép bạn duyệt các trang web bị hạn chế khi ở Trung Quốc.

Nếu bạn quyết định nâng cấp lên phiên bản trả phí (Lantern Pro), bạn sẽ nhận được nhiều dữ liệu hơn và tốc độ nhanh hơn. Sử dụng mã YJVD2WT của tôi và nhận 3 tháng miễn phí khi bạn đăng ký!

Kết luận cho VPN miễn phí

Không thể nhấn mạnh rằng bạn cần nhiều hơn 1 sự lựa chọn nếu bạn đang đi tuyến đường VPN miễn phí. Chúng tôi khuyên bạn nên tải xuống và thiết lập tất cả 3 VPN miễn phí ở trên trước khi bước chân vào Trung Quốc.


VPN trả phí

VPN trả phí (trong tiếng Trung) đề cập đến những VPN yêu cầu phí đăng ký hàng tháng (hoặc hàng năm). Điều mà nhiều trang web không thể nói với bạn là ngay cả VPN trả phí cũng không hoạt động 100%. Thông thường, các VPN đang trong một cuộc chạy đua vũ trang với Great Firewall. Khi Tường lửa thực hiện cập nhật thuật toán để chặn VPN, VPN sẽ tham gia vào một cuộc tranh giành thời gian để bỏ chặn chính nó. Trong thời gian đó, VPN sẽ không thể truy cập công khai. Điều đó đang được nói, VPN trả phí có nhiều tùy chọn máy chủ hơn nên nhiều khả năng nó có thể kết nối thành công với một trong những máy chủ đó, so với VPN miễn phí thường chỉ có một vài vị trí máy chủ.

Đánh giá PureVPN

PureVPN là lựa chọn hàng đầu của chúng tôi cho VPN trả phí do khả năng chi trả và hồ sơ theo dõi của nó.

PureVPN có một bộ máy chủ đặc biệt được Tối ưu hóa cho Trung Quốc, cho phép người dùng bỏ qua Great Firewall của Trung Quốc một cách hiệu quả và tự động. Trong trường hợp Tường lửa bị chặn mạnh, chỉ cần liên hệ với bộ phận hỗ trợ PureVPN rất nhạy. Sau đó, họ sẽ hướng dẫn bạn thực hiện các bước thủ công để kết nối với máy chủ, trong khi họ sửa ứng dụng chính của họ. (Tôi đã thử điều này trước đây.)

Đăng ký PureVPN bằng liên kết PureVPN chính thức này.

Khuyến mãi: Sử dụng mã phiếu giảm giá: discount10 để được giảm thêm 10% khi đăng ký PureVPN.

Đánh giá NordVPN

NordVPN luôn được xếp hạng hàng đầu trong số tất cả các VPN trực tuyến. NordVPN có trụ sở tại Panama, nơi không có luật lưu giữ dữ liệu bắt buộc nên họ hoàn toàn không lưu trữ nhật ký.

NordVPN cũng có chức năng các máy chủ bị che khuất trong các ứng dụng khác.

Đăng ký NordVPN bằng liên kết NordVPN chính thức này.

Kết luận cho VPN trả phí

Nhiều trang web không cho bạn biết điều này, nhưng vào năm 2019, ngay cả VPN trả phí cũng không hoạt động 100% tại Trung Quốc. Ngoài ra, nó phụ thuộc vào thành phố, đôi khi nó hoạt động ở Bắc Kinh nhưng không phải Thượng Hải và ngược lại. Các VPN tốt như trên hoạt động liên tục để cập nhật thuật toán của họ để giảm thiểu thời gian chết. Bạn chắc chắn vẫn muốn bổ sung VPN trả phí của mình với 1 hoặc 2 VPN miễn phí để phục vụ như một bản sao lưu.


Thẻ SIM Hồng Kông-Ma Cao

Phương pháp hoàn hảo để vượt qua Bức tường lửa vĩ đại của Trung Quốc là sử dụng thẻ SIM Hồng Kông-Ma Cao. Điều này là do mặc dù Hồng Kông và Ma Cao là một phần của Trung Quốc, nhưng không có Tường lửa ở đó theo luật của One One, Two Systems. Tóm lại, bạn chắc chắn sẽ có thể truy cập Facebook, WhatsApp, Google bằng thẻ SIM này.

Đây là một tùy chọn tuyệt vời nếu bạn là người dùng internet nhẹ đến trung bình (thẻ SIM có giới hạn dữ liệu nhanh là 6 GB, sau đó bạn vẫn có dữ liệu nhưng tốc độ giảm xuống còn 128kb / giây).

Mẹo: Bạn nên mua thẻ SIM từ China Unicom vì đây là một trong những công ty viễn thông lớn nhất và đáng tin cậy nhất ở Trung Quốc.

Thẻ SIM China Unicom (Lựa chọn Amazon Amazon):


The Greatest China 30-Day Data SIM

English version: The Complete Guide to VPN in China

Posted in Uncategorized | Tagged , , | Leave a comment

中国のVPNの完全ガイド

中国でGmail、YouTube、Facebook、WhatsAppにアクセスする方法

中国ではいくつかの重要なWebサイトがブロックされていることはよく知られています。

  • Googleの製品スイート全体。 これには、Gmail、Google検索、YouTube、Googleドライブ、Google Scholarなどが含まれます。
  • Facebookの製品スイート全体。 Facebookが所有しているため、これにはWhatsAppも含まれます。
  • Twitterなど、他のほとんどの「Western」ソーシャルメディア。
  • WordPress.com、Blogger.comなど、ほとんどのブログサイト。 これには、ログインページだけでなく、WordPress.com、Blogger.comなどによって作成されたすべてのサイトも含まれます。
  • Dropboxなどのほとんどのファイル共有サイト。
  • ウィキペディア

トファイアウォールは、ビジネスマン、学生、または単なる観光客であるかどうかにかかわらず、ほとんどの人にとって不便な多くの重要なサービスをブロックしています。 ファイアウォールがより強力になり、多くのVPNが以前ほどうまく機能しないため、近年(2019年以降)悪化しています。

この包括的なガイドでは、中国のグレートファイアウォールをバイパスし、Google、YouTube、Facebookなどに接続するのに役立つさまざまなオプション(VPNなど)について説明します。 無料サービスと有料サービス、および非VPNソリューションが含まれます。

***非常に重要:無料または有料のすべてのVPNは、中国に入る前にダウンロードして設定する必要があります。 中国に入国すると、VPNでアカウントをダウンロードまたは設定できない場合があります。


無料のVPN

ほとんどのWebサイトでは、無料VPNについては何のメリット(手数料)も得られないため、無料VPNについては説明していません。 ここでは、信頼できる信頼できる無料のVPNのみをお勧めします。 データを盗んだり漏洩したりする可能性のある日陰の「無料の」VPNが存在することに注意してください。 以下の無料VPNでは、クレジットカードデータは必要ありません。

***重要:無料のVPNのみに依存している場合は、2つまたは3つの選択肢をダウンロードして設定することをお勧めします。 これは、通常、無料のVPNは安定性が低く、サーバーの場所が少ないためにブロックされる傾向があるためです。

Windscribe Free VPNレビュー

実際の専門会社からの非常にまともな無料VPN。 毎月リセットされる約10 GBの無料のデータ帯域幅が得られ、友達にツイートしたり紹介したりすることでさらにデータを取得できる可能性があります。

Windscribe 10 GBは無料で、Twitterでツイートするだけでさらに多くの可能性があります。

私は個人的に中国のさまざまな都市でWindscribeの無料版を試してみましたが、それは(ほとんどの場合)動作します。 ただし、完全な接続を期待しないでください。 無料のWindscribeを使用する場合は、Windscribeの公式Webサイトでサインアップしてください

TunnelBear無料レビュー

TunnelBearは、クレジットカード情報を必要としない無料プラン(毎月500 MB)も提供しています。 私の経験では、Windscribe FreeはTunnelBear freeよりも優れています(接続の可能性とサーバーの場所の数に基づきます)。 ただし、そうは言っても、Windscribeが接続できないのに、TunnelBearはいつでも接続できることが非常によく起こります。 したがって、Free WindscribeとTunnelBearの両方を入手することをお勧めします。

ランタンVPN無料レビュー

Lantern VPNは、VPNではなく、「ピアネットワーク共有」ツールという意味でユニークです。 VPNとは動作が異なるため、他のVPNがブロックされている間はブロックされない場合があります。 Lanternには無料オプション(URL:https://getlantern.org/)があり、中国にいる間に制限付きウェブサイトを閲覧できます。

有料版(Lantern Pro)にアップグレードすることにした場合、より多くのデータとより高速な速度が得られます。 私のコードYJVD2WTを使用して、サインアップすると3か月間無料で利用できます!

無料のVPNの結論

Free VPNルートを利用する場合は、複数の選択肢が必要であることを強調することはできません。 中国に足を踏み入れる前に、上記の3つの無料VPNをすべてダウンロードしてセットアップすることを強くお勧めします。


有料VPN

有料VPN(中国語の翻訳)は、月間(または年単位)のサブスクリプション料金が必要なVPNを指します。多くのサイトがあなたに言っていないのは、有料VPNでさえ100%動作しないということです。通常、VPNはGreat Firewallとの軍拡競争にあります。ファイアウォールがVPNをブロックするためにアルゴリズムの更新を行うと、VPNはそれ自体のブロックを解除するためのタイムスクランブルを行います。その間、VPNは公開されません。そうは言っても、有料のVPNにはより多くのサーバーオプションがあるため、通常はサーバーの数が少ない無料のVPNと比較して、それらのサーバーの1つに正常に接続できる可能性が高くなります。

PureVPNレビュー

PureVPNは、手頃な価格と実績により、有料VPNの最高の選択肢です。

PureVPNには、特別な「中国向けに最適化された」サーバーセットがあり、ユーザーは中国のグレートファイアウォールを効果的かつ自動的にバイパスできます。ファイアウォールによる激しいブロッキングが発生した場合は、PureVPNサポートにお問い合わせください。次に、メインアプリを修正しながら、サーバーに接続するためのアドホックな手動手順を指示します。 (私は以前これを試しました。)

この公式PureVPNリンクを使用してPureVPNにサインアップしてください

プロモーション:クーポンコード:discount10を使用して、PureVPNサブスクリプションをさらに10%割引します。

NordVPNレビュー

NordVPNは、すべてのオンラインVPNの中で常にトップにランクされています。 NordVPNはパナマに本拠を置いていますが、パナマには必須のデータ保持法がないため、ログは絶対に保存されません。

NordVPNには、ユーザーのトラフィックを偽装してファイアウォールで検出されないようにする「難読化サーバー」機能もあります。

この公式のNordVPNリンクを使用してNordVPNにサインアップしてください

有料VPNの結論

多くのサイトはこれを教えてくれませんが、2019年には中国では有料VPNでさえ100%動作しません。 また、都市にもよりますが、時には北京では機能しますが上海では機能せず、その逆もあります。 上記のような優れたVPNは、ダウンタイムを最小限に抑えるためにアルゴリズムを常に更新しています。 バックアップとして機能する無料のVPNを1つまたは2つ追加して、有料VPNを確実に補完する必要があります。


香港マカオSIMカード

中国のグレートファイアウォールをバイパスする簡単な方法は、香港とマカオのSIMカードを使用することです。 これは、香港とマカオが中国の一部であるにもかかわらず、「1つの国、2つのシステム」法の下にファイアウォールが存在しないためです。 要約すると、このSIMカードを使用して、Facebook、WhatsApp、Googleに確実にアクセスできます。

軽度から中程度のインターネットユーザーの場合、これは優れたオプションです(SIMカードには6 GBの高速データ制限があり、その後はデータはありますが、速度は128kbpsに低下します)。

ヒント:SIMカードはChina Unicomから購入する必要があります。これは、中国で最大かつ最も信頼性の高い通信会社の1つです。

China Unicom SIMカード(Amazon’s Choice):


The Greatest China 30-Day Data SIM

English version: Complete Guide to China VPN

Posted in Uncategorized | Tagged , , | Leave a comment

중국 VPN에 대한 완벽한 가이드

중국의 Gmail, YouTube, Facebook, WhatsApp에 액세스하는 방법

중국에서는 몇 가지 필수 웹 사이트가 차단되어 있습니다.

  • 전체 Google 제품군 여기에는 Gmail, Google 검색, YouTube, Google 드라이브, Google 학술 검색 등이 포함됩니다.
  • 전체 Facebook 제품군. Facebook이 소유하고 있기 때문에 WhatsApp도 포함됩니다.
    트위터와 같은 대부분의 다른“서부”소셜 미디어.
  • WordPress.com, Blogger.com을 포함한 대부분의 블로그 사이트. 여기에는 로그인 페이지뿐만 아니라 WordPress.com, Blogger.com 등으로 만든 모든 사이트도 포함됩니다.
  • Dropbox와 같은 대부분의 파일 공유 사이트
  • 위키 백과

보시다시피, Great Firewall of China는 사업가, 학생 또는 단순한 관광객이든 대부분의 사람들에게 불편을 줄 수있는 많은 필수 서비스를 차단합니다. 방화벽이 훨씬 강력 해지고 많은 VPN이 제대로 작동하지 않아 최근 몇 년간 (2019 년 이후) 악화되었습니다.

이 포괄적 인 가이드에서는 중국의 방화벽을 우회하고 Google, YouTube, Facebook 등에 연결하는 데 도움이되는 다양한 옵션 (VPN 등)을 다룹니다. 무료 및 유료 서비스는 물론 비 VPN 솔루션도 포함됩니다.

*** 매우 중요 : 중국에 입국하기 전에 무료 또는 유료 VPN을 모두 다운로드하여 설정해야합니다. 중국에 입국하면 VPN에서 계정을 다운로드하거나 설정하지 못할 수 있습니다.


무료 VPN

대부분의 웹 사이트는 무료 VPN에 대해 알려주지 않으므로 무료 VPN에 대해 알려주지 않습니다. 여기서는 신뢰할 수 있고 안정적인 무료 VPN 만 권장합니다. 데이터를 훔치거나 유출 할 가능성이있는 그늘진“무료”VPN이 있습니다. 아래의 무료 VPN에는 신용 카드 데이터가 필요하지 않습니다.

*** 중요 : 무료 VPN에만 의존하는 경우 2 개 또는 3 개의 대안을 다운로드하고 설정하는 것이 좋습니다. 서버 위치가 적을수록 무료 VPN은 일반적으로 안정성이 떨어지고 차단되기 쉽습니다.

Windscribe 무료 VPN 검토

실제 전문 회사에서 제공하는 매우 괜찮은 무료 VPN입니다. 매달 재설정되는 약 10GB의 무료 데이터 대역폭이 제공되며 친구를 트윗하거나 추천하여 더 많은 것을 얻을 수 있습니다.

Twitter에서 트위터를 통해 더 많은 것을 얻을 수있는 10GB의 무료 Windscribe.

나는 중국의 다른 도시에서 개인적으로 무료 버전의 Windscribe를 사용해 보았으며 (대부분) 작동합니다. 완벽한 연결을 기대하지 마십시오. Free Windscribe를 사용하기로 결정한 경우 공식 Windscribe 웹 사이트에서 가입하십시오.

TunnelBear 무료 검토

TunnelBear는 또한 신용 카드 정보가 필요없는 무료 요금제 (매월 500MB)를 제공합니다. 내 경험에 따르면 Windscribe Free는 TunnelBear free (연결 기회 및 서버 위치 수 기준)보다 낫습니다. 그러나 Windscribe가 할 수없는 동안 언제라도 TunnelBear를 연결할 수 있다는 것은 매우 잘 알려진 사실입니다. 따라서 Free Windscribe와 TunnelBear를 모두 사용하는 것이 좋습니다.

랜턴 VPN 무료 검토

랜턴 VPN은 VPN이 아니라 “피어 네트워크 공유”도구라는 점에서 독특합니다. VPN과 다르게 작동하기 때문에 다른 VPN이 차단 된 동안에는 차단되지 않을 수 있습니다. Lantern에는 중국에있는 동안 제한된 웹 사이트를 탐색 할 수있는 무료 옵션 (URL : https://getlantern.org/)이 있습니다.

유료 버전 (Lantern Pro)으로 업그레이드하기로 결정하면 더 많은 데이터와 더 빠른 속도를 얻을 수 있습니다. 내 코드 YJVD2WT를 사용하고 가입하면 3 개월 무료로 이용할 수 있습니다!

무료 VPN에 대한 결론

무료 VPN 경로를 사용하는 경우 하나 이상의 선택이 필요하다는 것은 아무리 강조해도 지나치지 않습니다. 중국에 들어가기 전에 위의 3 가지 무료 VPN을 모두 다운로드하여 설정하는 것이 좋습니다.


유료 VPN

유료 VPN (중국어)은 월간 (또는 연간) 가입비가 필요한 VPN을 나타냅니다. 많은 사이트에서 사용자에게 알리지 않는 것은 유료 VPN도 100 % 작동하지 않는다는 것입니다. 일반적으로 VPN은 Great Firewall과 경쟁이 치열합니다. 방화벽이 VPN을 차단하기 위해 알고리즘을 업데이트하면 VPN은 자체적으로 차단을 해제하기 위해 시간이 걸리게됩니다. 이 기간 동안 대중은 VPN에 액세스 할 수 없습니다. 즉, 유료 VPN에는 더 많은 서버 옵션이 있으므로 일반적으로 몇 개의 서버 위치 만있는 무료 VPN에 비해 해당 서버 중 하나에 성공적으로 연결할 수 있습니다.

PureVPN 검토

PureVPN은 합리적인 가격과 실적으로 인해 유료 VPN을위한 최고의 선택입니다.

PureVPN에는 특별한 “중국에 최적화 된”서버 세트가 있으며,이를 통해 사용자는 중국의 방화벽을 효과적으로 자동으로 우회 할 수 있습니다. 방화벽에 의한 강력한 차단의 경우, 매우 반응이 빠른 PureVPN 지원에 문의하십시오. 그런 다음 메인 앱을 수정하는 동안 서버에 연결하기 위해 수동 단계를 임시로 안내합니다. (나는 전에 이것을 시도했다.)

이 공식 PureVPN 링크를 사용하여 PureVPN에 가입하십시오.

프로모션 : 쿠폰 코드 : discount10을 사용하여 PureVPN 구독시 추가 10 % 할인을 받으십시오.

NordVPN 검토

NordVPN은 온라인에서 모든 VPN 중에서 지속적으로 최고 순위를 차지합니다. NordVPN은 필수 데이터 보존법이 없으므로 파나마를 기반으로하므로 로그를 절대 저장하지 않습니다.

NordVPN에는 방화벽에 의해 탐지되는 것을 피하기 위해 사용자의 트래픽을 위장하는 “”난독 화 된 서버 “기능도 있습니다.

이 공식 NordVPN 링크를 사용하여 NordVPN에 가입하십시오.

유료 VPN에 대한 결론

많은 사이트에서이를 알려주지 않지만 2019 년에는 유료 VPN도 중국에서 100 % 작동하지 않습니다. 또한 도시에 따라 다르며 때로는 베이징에서 작동하지만 상하이에서는 작동하지 않으며 그 반대도 마찬가지입니다. 위와 같은 우수한 VPN은 다운 타임을 최소화하기 위해 알고리즘을 지속적으로 업데이트합니다. 여전히 유료 VPN을 1 개 또는 2 개의 무료 VPN으로 보완하여 백업으로 사용할 수 있습니다.


홍콩 마카오 SIM 카드

중국의 방화벽을 우회하는 가장 확실한 방법은 홍콩-마카오 SIM 카드를 사용하는 것입니다. 홍콩과 마카오는 중국의 일부이지만“일 국가, 두 시스템”법에 따라 방화벽이 없기 때문입니다. 요약하면이 SIM 카드를 사용하여 Facebook, WhatsApp, Google에 확실히 액세스 할 수 있습니다.

이 방법은 인터넷 사용자가 보통이거나 중간 정도 인 사용자 (SIM 카드의 데이터 제한이 6GB로 빠른 후에도 데이터는 있지만 속도는 128kbps로 감소) 인 경우 탁월한 옵션입니다.

팁 : China Unicom은 중국에서 가장 크고 가장 안정적인 통신 회사 중 하나이므로 SIM 카드를 구입해야합니다.


The Greatest China 30-Day Data SIM

English version: Complete Guide to VPN in China

Posted in Uncategorized | Tagged , | Leave a comment

Jack Ma Returns to Hupan: Birthplace of Alibaba

Hupan Garden, Jack Ma’s Hangzhou apartment in 1999, is where it all began for Alibaba. On the eve of the company’s 20th birthday, we took Ma back to Hupan to reflect on those early days and what it took to build Alibaba into what it is today.

Posted in Uncategorized | Tagged , | Leave a comment

Guía completa de VPN en China

Cómo acceder a Gmail, YouTube, Facebook, WhatsApp en China

Es bien sabido que varios sitios web esenciales están bloqueados en China:

  • El conjunto completo de productos de Google. Esto incluye Gmail, búsqueda de Google, YouTube, Google Drive, Google Scholar, etc.
  • Todo el conjunto de productos de Facebook. Esto también incluye WhatsApp, ya que es propiedad de Facebook.
  • La mayoría de las otras redes sociales “occidentales”, como Twitter.
  • La mayoría de los sitios de blogs, incluidos WordPress.com, Blogger.com. Esto incluye no solo las páginas de inicio de sesión, sino también todos los sitios creados por WordPress.com, Blogger.com, etc.
  • La mayoría de los sitios para compartir archivos, como Dropbox.
  • Wikipedia

Como puede ver, el Gran Cortafuegos de China bloquea muchos servicios esenciales que molestarán a la mayoría de las personas, ya sea usted un hombre de negocios, un estudiante o simplemente un turista casual. Ha empeorado en los últimos años (2019 en adelante) ya que el Firewall se ha vuelto mucho más fuerte y muchas VPN no funcionan tan bien como lo hicieron.

En esta guía completa, cubriremos una variedad de opciones (VPN y más) que lo ayudarán a evitar el Gran Cortafuegos de China y conectarse a Google, YouTube, Facebook, etc. Incluimos servicios gratuitos y de pago, así como soluciones que no son de VPN.

*** Muy importante: todas las VPN, ya sean gratuitas o de pago, deben descargarse y configurarse antes de ingresar a China. Una vez que ingrese a China, es posible que no pueda descargar o configurar una cuenta en la VPN.


VPN gratis

La mayoría de los sitios web no le informan sobre las VPN gratuitas, ya que no obtienen ningún beneficio (comisión) al hacerlo. Aquí solo recomendaremos VPN gratuitas confiables y confiables. Tenga en cuenta que existen algunas VPN “gratuitas” con sombra que tienen el potencial de robar o filtrar sus datos. Las siguientes VPN gratuitas no requieren ningún dato de tarjeta de crédito.

*** Importante: si solo confía en VPN gratuitas, se recomienda descargar y configurar 2 o 3 alternativas. Esto se debe a que las VPN gratuitas suelen ser menos estables y más propensas a bloquearse, ya que hay menos ubicaciones de servidor.

Revisión de VPN gratuita de Windscribe

Una VPN gratuita muy decente que es de una compañía profesional real. Obtiene alrededor de 10 GB de ancho de banda de datos gratis que se restablece cada mes, con el potencial de obtener más tuiteando o refiriéndose a sus amigos.

Windscribe 10 GB gratis con potencial para obtener más simplemente tuiteando en Twitter.

He probado personalmente la versión gratuita de Windscribe en diferentes ciudades de China, y funciona (la mayoría de las veces). Sin embargo, no esperes una conexión perfecta. Si decide utilizar Free Windscribe, regístrese aquí en el sitio web oficial de Windscribe.

Revisión gratuita de TunnelBear

TunnelBear también proporciona un plan gratuito (500 MB mensuales) que no requiere ninguna información de su tarjeta de crédito. Según mi experiencia, Windscribe Free es mejor que TunnelBear gratis (según la posibilidad de conexión y el número de ubicaciones del servidor). Sin embargo, dicho esto, es muy posible que en cualquier momento dado, TunnelBear se pueda conectar mientras que Windscribe no. Por lo tanto, la recomendación es obtener Free Windscribe y TunnelBear.

Revisión gratuita de Lantern VPN

Lantern VPN es única en el sentido de que no es una VPN, sino más bien una herramienta de “intercambio de redes entre pares”. Dado que funciona de manera diferente a una VPN, podría darse el caso de que no esté bloqueado mientras que otras VPN sí lo están. Lantern tiene una opción gratuita (URL: https://getlantern.org/) que le permite navegar por sitios web restringidos mientras está en China.

Si decide actualizar a la versión paga (Lantern Pro), obtendrá más datos y una velocidad más rápida. ¡Use mi código YJVD2WT y obtenga 3 meses gratis cuando se registre!

Conclusión para VPN gratis

No se puede enfatizar demasiado que necesita más de 1 opción si va a la ruta VPN gratuita. Se recomienda encarecidamente que descargue y configure todas las 3 VPN gratuitas anteriores antes de ingresar a China.


VPN pagas

Las VPN de pago (翻墙 软件 en chino) se refieren a aquellas que requieren una tarifa de suscripción mensual (o anual). Lo que muchos sitios no le dicen es que incluso las VPN de pago no funcionan al 100%. Por lo general, las VPN están en una carrera armamentista con el Gran Firewall. Una vez que el firewall realiza una actualización del algoritmo para bloquear la VPN, la VPN se comprometerá en una lucha de tiempo para desbloquearse. Durante ese tiempo, la VPN no será accesible al público. Dicho esto, las VPN de pago tienen más opciones de servidor, por lo que es más probable que pueda conectarse con éxito a uno de esos servidores, en comparación con las VPN gratuitas que generalmente solo tienen unas pocas ubicaciones de servidor.

Revisión de PureVPN

PureVPN es nuestra mejor opción para VPN de pago debido a su asequibilidad y su historial.

PureVPN tiene un conjunto especial de servidores “Optimizado para China”, que permiten a los usuarios evitar el Gran Firewall de China de manera efectiva y automática. En el caso de un bloqueo intenso por parte del Firewall, solo contacte al soporte de PureVPN que es muy receptivo. Luego lo guiarán a pasos manuales ad hoc para conectarse a un servidor, mientras arreglan su aplicación principal. (He intentado esto antes).

Regístrese en PureVPN utilizando este enlace oficial de PureVPN.

Revisión de NordVPN

NordVPN se clasifica constantemente como el mejor entre todas las VPN en línea. NordVPN tiene su sede en Panamá, que no tiene una ley de retención de datos obligatoria, por lo que no almacenan registros.

NordVPN también tiene la función de “servidores ofuscados” que disfraza el tráfico de un usuario para evitar que sea detectado por el cortafuegos.

Regístrese en NordVPN utilizando este enlace oficial de NordVPN.

Conclusión para las VPN pagas

Muchos sitios no te dicen esto, pero en 2019 incluso las VPN pagas no funcionan al 100% en China. También depende de la ciudad, a veces funciona en Beijing pero no en Shanghai y viceversa. Las buenas VPN como las anteriores funcionan constantemente para actualizar su algoritmo y minimizar el tiempo de inactividad. Definitivamente, querrás complementar tu VPN de pago con 1 o 2 VPN gratuitas para que sirvan como respaldo.


Tarjeta SIM Hong Kong-Macao

El método infalible de evitar el Gran Firewall de China es usar una tarjeta SIM de Hong Kong-Macao. Esto se debe a que aunque Hong Kong y Macao son parte de China, no existe un cortafuegos en virtud de la ley “Un país, dos sistemas”. En resumen, definitivamente podrá acceder a Facebook, WhatsApp, Google usando esta tarjeta SIM.

Esta es una excelente opción si es un usuario de Internet ligero a moderado (la tarjeta SIM tiene un límite de datos rápido de 6 GB, después de lo cual todavía tiene datos, pero la velocidad se reduce a 128 kbps).

Consejo: debe comprar la tarjeta SIM de China Unicom, ya que es una de las compañías de telecomunicaciones más grandes y confiables de China.

Tarjeta SIM China Unicom (Elección de Amazon):


The Greatest China 30-Day Data SIM

English version: Complete Guide to VPN in China

Posted in Uncategorized | Tagged , | Leave a comment

中国VPN完整指南

如何在中国访问Gmail,YouTube,Facebook,WhatsApp

众所周知,中国有几个重要网站被封锁:

  • 整套谷歌产品套件。 这包括Gmail,Google搜索,YouTube,Google云端硬盘
  • Google学术搜索等。
  • 整个Facebook套件产品。 这也包括WhatsApp,因为它归Facebook所有。
  • 大多数其他“西方”社交媒体,如Twitter。
  • 大多数博客网站,包括WordPress.com,Blogger.com。 这不仅包括登录页面,还包括WordPress.com,Blogger.com等创建的所有网站。
  • 大多数文件共享网站,例如Dropbox。
  • 维基百科

正如您所看到的,中国的防火墙阻止了许多基本服务,这些服务会给大多数人带来不便,无论您是商人,学生还是休闲旅游者。 近年来(2019年以后)它已经恶化,因为防火墙变得越来越强大,许多VPN不能像以前那样运行良好。

在本综合指南中,我们将介绍各种选项(VPN等),它们将帮助您绕过中国的防火墙,并连接到谷歌,YouTube,Facebook等。 我们包括免费和付费服务,以及非VPN解决方案。

***非常重要:在您进入中国之前,必须下载并设置所有免费或付费的VPN。 进入中国后,您可能无法在VPN上下载或设置帐户。


免费VPN

大多数网站都没有告诉你有关免费VPN的事情,因为他们没有从中获益(佣金)。 我们只会在此推荐值得信赖,可靠的免费VPN。 请注意,存在一些可能会窃取或泄露数据的阴影“免费”VPN。 以下免费VPN不需要任何信用卡数据。

***重要提示:如果您只依赖Free VPN,建议下载并设置2或3个备选方案。 这是因为Free VPN通常不太稳定,并且由于服务器位置较少而更容易被阻止。

Windscribe免费VPN评论

一个非常体面的免费VPN,来自一个真正的专业公司。 您可以获得大约10 GB的免费数据带宽,每月可以重置,有可能通过推特或引用您的朋友获得更多。

Windscribe 10 GB免费,可以通过Twitter上的推特获得更多。

我亲自在中国的不同城市尝试过Windscribe的免费版本,它的工作原理(大部分时间都是如此)。 不要指望完美连接。 如果您决定使用免费Windscribe,请在Windscribe官方网站上注册

TunnelBear免费评论

TunnelBear还提供免费计划(每月500 MB),不需要您提供任何信用卡信息。根据我的经验,Windscribe Free比TunnelBear更好(基于连接的机会和服务器位置的数量)。然而,话虽如此,很可能会发生在任何给定时间,TunnelBear可以连接,而Windscribe不能。因此,建议同时获得Free Windscribe和TunnelBear。

灯笼(蓝灯)VPN免费评论

Lantern VPN在某种意义上是独一无二的,它不是VPN,而是“对等网络共享”工具。由于它与VPN的工作方式不同,因此可能会出现其他VPN无法阻止的情况。 Lantern有一个免费选项(URL:https://getlantern.org/),允许您在中国浏览受限制的网站。

如果您决定升级到付费版本(Lantern Pro),您将获得更多数据和更快的速度。使用我的代码YJVD2WT,并在注册时免费获得3个月!

免费VPN的结论

如果你要使用免费VPN路由,那么你肯定需要多于一个选择。强烈建议您在踏入中国之前下载并设置上述所有3个免费VPN。


付费VPN

付费VPN(翻译软件,中文)是指那些需要每月(或每年)订阅费用的人。 许多网站没有告诉你的是,即使付费VPN也无法100%运行。 通常,VPN与Great Firewall进行军备竞赛。 一旦防火墙进行算法更新以阻止VPN,VPN将进行时间加扰以解锁自身。 在此期间,公众无法访问VPN。 话虽如此,付费VPN有更多的服务器选项,因此与通常只有少量服务器位置的免费VPN相比,它更有可能成功连接到其中一台服务器。

PureVPN评论

PureVPN是付费VPN的首选,因为它具有可承受性和良好的记录。

PureVPN拥有一套特殊的“中国优化”服务器,可以让用户有效,自动地绕过中国的防火墙。 如果防火墙严重阻塞,只需联系PureVPN支持,该支持非常敏感。 然后,他们将指导您进行特定的手动步骤以连接到服务器,同时修复他们的主应用程序。 (我以前试过这个。)

使用此官方PureVPN链接注册PureVPN。

NordVPN评论

NordVPN一直在所有VPN在线中排名第一。 NordVPN位于巴拿马,没有强制数据保留法,因此绝对不存储日志。

NordVPN还具有“混淆服务器”功能,可以伪装用户的流量,以更好地避免被防火墙检测到。

使用此官方NordVPN链接注册NordVPN。

付费VPN的结论

许多网站都没有告诉你这一点,但在2019年,即使付费VPN在中国也不能100%运作。 它也取决于城市,有时它在北京工作但不在上海工作,反之亦然。 像上面这样的好的VPN不断更新其算法以最大限度地减少停机时间。 您仍然肯定希望用1或2个免费VPN补充您的付费VPN作为备份。


港澳SIM卡

绕过中国防火墙的万无一失的方法是使用港澳SIM卡。 这是因为即使香港和澳门是中国的一部分,根据“一国两制”法,也没有防火墙。 总之,您一定可以使用此SIM卡访问Facebook,WhatsApp,Google。

如果您是轻度到中度的互联网用户(SIM卡具有6 GB的快速数据限制,之后您仍然拥有数据但速度降低到128kbps),这是一个很好的选择。

提示:您应该从中国联通购买SIM卡,因为它是中国最大,最可靠的电信公司之一。

中国联通SIM卡(亚马逊的选择):


The Greatest China 30-Day Data SIM

English version of this page: Complete Guide to VPN in China

Posted in Uncategorized | Tagged , | Leave a comment

Complete Guide to VPN in China

How to Access Gmail, YouTube, Facebook, WhatsApp in China

It is well-known that several essential websites are blocked in China:

  • The entire Google suite of products. This includes Gmail, Google search, YouTube, Google Drive, Google Scholar, etc.
  • The entire Facebook suite of products. This also includes WhatsApp since it is owned by Facebook.
  • Most other “Western” social media, such as Twitter.
  • Most blogging sites, including WordPress.com, Blogger.com. This includes not only the login pages but also all sites created by WordPress.com, Blogger.com, etc.
  • Most file-sharing sites, such as Dropbox.
  • Wikipedia

As you can see, the Great Firewall of China blocks many essential services that will inconvenience most people, whether you are a businessman, student, or just a casual tourist. It has worsened in recent years (2019 onwards) as the Firewall has gotten much stronger and many VPNs do not work as well as they did.

In this comprehensive guide, we will cover a variety of options (VPNs and more) that will help you bypass the Great Firewall of China, and connect to Google, YouTube, Facebook, et cetera. We include Free as well as Paid services, as well as non-VPN solutions.

***Very Important: All the VPNs be it free or paid must be downloaded and set up before you enter China. Once you enter China, you may not be able to download or set up an account on the VPN.


Free VPNs

Most websites do not tell you about Free VPNs as they gain no benefit (commission) from doing so. We will only recommend trusted, reliable free VPNs here. Do note that there exists some shady “free” VPNs that have the potential to steal or leak your data. The below Free VPNs do not require any credit card data.

***Important: If you are only relying on Free VPNs, it is recommended to download and set up 2 or 3 alternatives. This is because Free VPNs are usually less stable and more prone to be blocked as there are fewer server locations.

Windscribe Free VPN Review

A very decent Free VPN that is from a actual professional company. You get around 10 GB free data bandwidth that resets each month, with potential to get more by tweeting or referring to your friends.

Windscribe 10 GB free with potential to get more just by Tweeting on Twitter.

I have personally tried the Free version of Windscribe in different cities in China, and it works (most of the time). Do not expect perfect connection though. If you decide to go with Free Windscribe, sign up here at the official Windscribe website.

TunnelBear Free Review

TunnelBear also provides a free plan (500 MB monthly) that does not require any credit card info from you. Based on my experience, Windscribe Free is better than TunnelBear free (based on chance of connection, and number of server locations). However, that being said, it can very well occur that at any given time, TunnelBear can connect while Windscribe cannot. Hence, the recommendation is to get both Free Windscribe and TunnelBear.

Lantern VPN Free Review

Lantern VPN is unique in the sense that it is not a VPN, but rather a “peer network sharing” tool. Since it works differently from a VPN, it could be the case that it is not blocked while other VPNs are. Lantern has a Free option (URL: https://getlantern.org/) which allows you to browse restricted websites while in China.

If you decide to upgrade to the paid version (Lantern Pro), you get more data and faster speed. Use my code YJVD2WT and get 3 months free when you sign up!

Conclusion for Free VPNs

It cannot be overemphasized that you need more than 1 choice if you are going the Free VPN route. It is highly recommended that you download and setup all of the above 3 Free VPNs before stepping foot into China.


Paid VPNs

Paid VPNs (翻墙软件 in Chinese) refer to those that require a monthly (or yearly) subscription fee. What many sites don’t tell you is that even Paid VPNs do not work 100%. Typically the VPNs are in an arms race with the Great Firewall. Once the Firewall makes an algorithm update to block the VPN, the VPN will engage in a time scramble to unblock itself. During that time, the VPN will not be accessible to the public. That being said, paid VPNs have more server options so it is more likely that it can successfully connect to one of those servers, compared to free VPNs which typically only have a few server locations.

PureVPN Review

PureVPN is our top choice for Paid VPNs due to its affordability and its track record.

PureVPN has a special “Optimized for China” set of servers, which allow users to bypass the Great Firewall of China effectively and automatically. In the event of intense blocking by the Firewall, just contact the PureVPN support which is very responsive. They will then direct you to adhoc manual steps to connect to a server, while they fix their main app. (I have tried this before.)

Sign up for PureVPN using this official PureVPN link.

Promotion: Use the coupon code: discount10 for an extra 10% discount on PureVPN subscription.

NordVPN Review

NordVPN is consistently ranked top among all VPNs online. NordVPN is based in Panama which has no mandatory data retention law so they absolutely do not store logs.

NordVPN also has the ““obfuscated servers” function which disguises a user’s traffic to better avoid it being detected by the Firewall.

Sign up for NordVPN using this official NordVPN link.

Conclusion for Paid VPNs

Many sites don’t tell you this, but in 2019 even Paid VPNs do not work 100% in China. Also it depends on the city, sometimes it works in Beijing but not Shanghai and vice versa. Good VPNs like the above work constantly to update their algorithm to minimize the downtime. You would still definitely want to supplement your Paid VPN with 1 or 2 Free VPNs to serve as backup.


Hong Kong-Macau SIM Card

The foolproof method of bypassing the Great Firewall of China is to use a Hong Kong-Macau SIM card. This is because even though Hongkong and Macau are part of China, there is no Firewall there under the “One Country, Two Systems” law. In summary, you will definitely be able to access Facebook, WhatsApp, Google using this SIM card.

This is an excellent option if you are a light to moderate internet user (the SIM card has a fast data limit of 6 GB, after which you still have data but the speed is reduced to 128kbps).

Tip: You should purchase the SIM card from China Unicom as it is one of the largest and most reliable telecommunications company in China.

China Unicom SIM card (Amazon’s Choice):


The Greatest China 30-Day Data SIM

Posted in Uncategorized | Tagged , | 8 Comments

Excel: Find Sum, Average, Median by ignoring NA or invalid values

Today I just found out about the AGGREGATE function in Microsoft Excel, which allows you to find the sum, average, median, product and various other statistical numbers while ignoring NaN values.

The usual Excel function of AVERAGE will produce errors if any of the cells are invalid.

With AGGREGATE, for instance if we want to calculate the average (while ignoring invalid cells), we just type in the Excel formula

=AGGREGATE(1,6, [data])
Posted in Uncategorized | Tagged | 1 Comment