astronomy

Ken-ichi Kawarabayashi

Ken-ichi Kawarabayashi is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Ken-ichi Kawarabayashi rather than just read about it. In short: Ken-ichi Kawarabayashi (Japanese: 河原林健一, born 1975) is a Japanese graph theorist who works as a professor at the National Institute of Informatics and is known for his research on graph theory (particularly the theory of graph minors) and graph algorithms. Kawarabayashi was born on May 22, 1975, in Tokyo.

Key takeaways

Ken-ichi Kawarabayashi belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Ken-ichi Kawarabayashi to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Ken-ichi Kawarabayashi from memory before moving on to harder problems.

Reference excerpt

Ken-ichi Kawarabayashi (Japanese: 河原林健一, born 1975) is a Japanese graph theorist who works as a professor at the National Institute of Informatics and is known for his research on graph theory (particularly the theory of graph minors) and graph algorithms. Kawarabayashi was born on May 22, 1975, in Tokyo. He earned a bachelor's degree in mathematics from Keio University in 1998, a master's degree from Keio in 2000, and a PhD from Keio in 2001, researching the Lovász–Woodall conjecture under the supervision of Katsuhiro Ota. After temporary positions at Vanderbilt University and under the supervision of Paul Seymour at Princeton University, he became an assistant professor at Tohoku University in 2003, and moved to the National Institute of Informatics in 2006. In 2003, Kawarabayashi was one of three winners of the Kirkman Medal of the Institute of Combinatorics and its Applications, an award given by them annually to researchers within four years of their PhD. In 2015, he won the Spring Prize of the Mathematical Society of Japan, its highest honor. He was a keynote speaker at the 2015 International Colloquium on Automata, Languages and Programming. He was named as an ACM Fellow, in the 2025 class of fellows, "for his contributions to graph theory, graph algorithms, and their applications".

References

External links Google scholar profile

Worked examples

Example 1 — a first encounter with Ken-ichi Kawarabayashi

Start with the simplest possible case. Write down what Ken-ichi Kawarabayashi claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Ken-ichi Kawarabayashi before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Ken-ichi Kawarabayashi ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Ken-ichi Kawarabayashi

In research: Ken-ichi Kawarabayashi appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Ken-ichi Kawarabayashi in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Ken-ichi Kawarabayashi is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1975 births, Academic staff of Tohoku University, Fellows of the Association for Computing Machinery, so understanding it makes those chapters shorter.
In everyday life: Look for Ken-ichi Kawarabayashi outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Ken-ichi Kawarabayashi in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Ken-ichi Kawarabayashi means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Ken-ichi Kawarabayashi out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Ken-ichi Kawarabayashi in simple terms?

Why does Ken-ichi Kawarabayashi matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Ken-ichi Kawarabayashi?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Ken-ichi Kawarabayashi.