Hang-Hyun Jo

Hang-Hyun Jo

@socph.bsky.social

Associate Professor at The Catholic University of Korea; statistical physics and complex systems; co-author of "Bursty Human Dynamics" (Springer, 2018); https://sites.google.com/site/h2jo23/; visiting the University of Michigan

394 followers456 following280 posts

Hang-Hyun Jo reposted

Katie Mack
@astrokatie.com

A reminder, because it is almost that time of year: More children are killed by cars on Halloween than any other day of the year, by far. www.vox.com/future-perfe... If you're a parent, I hope you'll do what you can to keep kids safe. If you're driving on Saturday, PLEASE exercise extra caution.

Hang-Hyun Jo
@socph.bsky.social

"Shared joy is a double joy; shared sorrow is half sorrow" When I heard of it, I thought that sorrow follows the conservation law, thus it's more materialistic, whereas joy doesn't, thus it's more abstract.

Hang-Hyun Jo
@socph.bsky.social

Here I bookmark the mentioned works: www.journals.uchicago.edu/doi/10.1086/... www.jstor.org/stable/27459...

journals.uchicago.eduThe Predictability of Social Events | Journal of Political Economy: Vol 62, No 6
Stefano Angeli@sangeli.ficss.institute

Yes. Then the forecast becomes a fixed point: the one that is still true after people read it. Simon, Grunberg and Modigliani showed in 1954 that it can exist. My doubt is practical. People learn, so the reaction changes and the fixed point moves. Have you found a way around that?

Hang-Hyun Jo
@socph.bsky.social

brunch.co.kr/@socph/38

brunch.co.krAI 시대의 연구평가저널 플로스바이올로지(PLOS Biology)에 실린 "무엇을 위한 생물학 연구인가?"라는 글을 읽었다. 저자의 문제의식을 한 문장으로 정리하면, AI로 인해 논문이 곧 연구가 아니게 되었다는 것이다. 그리고 전산, 수학뿐 아니라 모든 계산 연구분야가 같은 문제를 겪기 시작했고 생물학도 예외는 아니라고 한다. 그럼 AI 이전에는 논문이 곧 연구였나? 물론
Hang-Hyun Jo
@socph.bsky.social

brunch.co.kr/@socph/37

brunch.co.krAI 시대, 연구의 가치제목이 너무 거창한데, 그래도 크게 한 번 생각해보자. AI가 뭐든지 다 알려주고 심지어 연구도 잘 해주는 시대에 인간이 '수제'로 하는 연구는 어떤 가치가 있을까라는 질문이다. 물론 연구분야마다 상황이 달라서 일반화하기는 힘들다. 하지만 이제는 분야를 불문하고 AI가 점점 더 많은 영향을 미치는 것도 사실이다. 애초에 연구란 무엇인가. 자연이나 사회 현
Hang-Hyun Jo
@socph.bsky.social

brunch.co.kr/@socph/36 [in Korean]

brunch.co.krAI-아리스토텔레스작년에 베이징대학교 물리학자들이 아카이브에 올린 논문을 알게 되었다. 그들은 물리학에 대한 사전 정보 없이도 주어진 실험 데이터로부터 물리법칙을 발견해내는 AI 구조를 만들었고 거기에 AI-뉴턴이라 이름붙였다. 자유롭게 움직이는 공이나 용수철에 매달린 물체의 운동에 대한 데이터로부터 뉴턴의 제2 운동법칙(가속도의 법칙)을 재발견할 수 있었다고 한다. 아직

Hang-Hyun Jo reposted

Gahyoun Gim
@dotchgahyoun.bsky.social

연구실 친구들의 관심사(모빌리티, 도심안전지표)와 도메인(네트워크)을 융합하여서, 인공지능 기반의 순찰 에이전트봇 디지털 트윈을 구현해 보았고 이번 과학치안 아이디어 공모전에 투고 및 발표한 결과, 국민(시민)부분에서 우수상을 수상하였습니다 👏👏👏 kipot.or.kr/user/ex19.do

Hang-Hyun Jo
@socph.bsky.social

Accepted for publication in Communications Physics!

Hang-Hyun Jo@socph.bsky.social

Our new preprint is out on arXiv: Hang-Hyun Jo, Naoki Masuda, Modeling non-Poissonian temporal hypergraphs by Markovian node dynamics, arXiv:2604.07694 arxiv.org/abs/2604.07694

arxiv.orgModeling non-Poissonian temporal hypergraphs by Markovian node dynamicsTemporal hypergraphs capture time-resolved group interactions among nodes. Empirical data support that time-stamped group interactions show bursty event sequences and non-trivial temporal correlations...

Hang-Hyun Jo reposted

Helen Czerski
@helenczerski.bsky.social

Replying to @helenczerski.bsky.social

It bugs me that we're normalising the idea that there's something wrong with long documents, or that they're not "worth" our time. There is huge value in careful thought, in detail and nuance, in exploration, and in the experiential journey that goes alongside that.

Hang-Hyun Jo reposted

Ann Arbor District Library
@aadl.org

Celebrate Korea Week at AADL Sept. 28-Oct. 4, packed full of Korean culture, crafts, cuisine, and more! Korea Week is held in partnership with the University of Michigan Nam Center for Korean Studies and the Korean Cultural Center of Washington D.C. → aadl.org/koreaweek

Hang-Hyun Jo
@socph.bsky.social

"At some point in life the world's beauty becomes enough. You don't need to photograph, paint or even remember it. It is enough. No record of it needs to be kept and you don't need someone to share it with or tell it to. When that happens — that letting go — you let go because you can."

Hang-Hyun Jo
@socph.bsky.social

"To write is not just to transcribe the mind’s ideas; it’s a form of transformation, turning a nascent, half-built thought into something sturdier, tougher, sharper. EM Forster wrote: “How do I know what I think until I see what I say?”"

Philip Ball@philipcball.bsky.social

I thought I'd repost this piece quoting the first sentence. Then I thought, no, the first paragraph. No, the first three. And I went on doing that until the final word. www.theguardian.com/books/ng-int...

theguardian.com‘I hate what AI is doing to the minds and happiness of the young’: Katherine Rundell on the view from the classroomEducation is at a crossroads, argues the author and academic. Should we embrace new technology in the name of efficiency, or is it time to fight back?
Hang-Hyun Jo
@socph.bsky.social

brunch.co.kr/@socph/30

brunch.co.kr동적네트워크 개념정리21세기 네트워크과학이 시작했을 때 주어진 데이터는 보통 정적네트워크였다. 또는 시간정보가 있는 경우에도 이를 무시한 정적네트워크로 바꾸어 연구하곤 했다. 하지만 정적네트워크 연구가 성숙해지고 시간정보가 포함된 네트워크 데이터도 많아지면서 2010년대 들어 동적네트워크 연구가 떠올랐다. 사실 네트워크를 연구하는 물리학자들은 구조 자체보다도 동역학에 관심이
Hang-Hyun Jo
@socph.bsky.social

brunch.co.kr/@socph/29

brunch.co.kr하이퍼그래프 논란지금까지 네트워크라고 하면 두 노드 사이의 상호작용을 링크로 표현한 것을 주로 가리켰다. 하지만 실제 현상들을 보면 둘보다 많은 노드들이 '동시에' 상호작용하는 경우도 있다. 이를테면 셋이나 네명의 연구자가 모여서 같이 논문을 쓰는 일이 그렇다. 이렇게 둘보다 많은 노드들의 상호작용을 어떻게 네트워크로 공부할 수 있을까. 그래서 나온 답이 하이퍼그래프(hy
Hang-Hyun Jo
@socph.bsky.social

After a couple of weeks of heatwave in Ann Arbor, now it feels like a Finnish summer. Several years ago, when I visited Aalto University in summer, I had to buy a "summer jacket".

Hang-Hyun Jo
@socph.bsky.social

Why does it take so long to get the volume and pages for the accepted paper in Scientific Reports? I need such information for the process in my university.

Hang-Hyun Jo@socph.bsky.social

Accepted for publication in Scientific Reports! I thank @tibebe12.bsky.social for his hard work.

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Hang-Hyun Jo
@socph.bsky.social

Why does it take so long to get the volume and pages for the accepted paper in Scientific Reports? I need such information for the process in my university.

Hang-Hyun Jo@socph.bsky.social

Accepted for publication in Scientific Reports! I thank @tibebe12.bsky.social for his hard work.

Hang-Hyun Jo
@socph.bsky.social

Finally my paper was assigned the volume and article number, after two months! www.nature.com/articles/s41... Coincidently, the article number contains my birth year and day, and the second digit of my birth month (if it's counted).

nature.comAnalysis framework for higher-order temporal correlations with applications to human heartbeats - Scientific ReportsScientific Reports - Analysis framework for higher-order temporal correlations with applications to human heartbeats
Hang-Hyun Jo
@socph.bsky.social

All of sudden, I wondered why the number of neighbors of a node in networks is called a "degree". In the original paper by Erdos and Renyi (1960), I found a sentence: "The number of edges starting from the point P of a graph G will be called the degree of P in G." But without any explanation.

Hang-Hyun Jo
@socph.bsky.social

I've never imagined that I'd worry about the air quality in Ann Arbor, until yesterday. Today it's getting worse and worse.

The New York Times@nytimes.com

Wildfire smoke can be seen via satellites from the Upper Midwest and Canada, across the Great Lakes and down to New York City. A heat dome is pushing temperatures close to 100 degrees across much of eastern Canada and has prompted alerts about poor air quality. nyti.ms/3RHmZnk

Hang-Hyun Jo
@socph.bsky.social

Oh, I've used "quite some" quite often in my everyday English conversation and didn't know it was not a standard English.

Philip Ball@philipcball.bsky.social

I'd go further: if we native English speakers expect English to be the lingua franca (ha!) of most of the world, everyone who uses it gets to influence how it evolves. Phrases that aren't standard English, like "quite some" and "allows to", are then no longer really "wrong" at all.

Hang-Hyun Jo reposted

Philip Ball
@philipcball.bsky.social

I'd go further: if we native English speakers expect English to be the lingua franca (ha!) of most of the world, everyone who uses it gets to influence how it evolves. Phrases that aren't standard English, like "quite some" and "allows to", are then no longer really "wrong" at all.

This post is unavailable.

Hang-Hyun Jo reposted

Taha Yasseri
@tahayasseri.bsky.social

Chapter 15: @kristinalerman.bsky.social on the Strong Friendship Paradox. Showing how the structure of social networks systematically biases our perceptions of reality. When our friends are not representative of the population, rare behaviours and opinions can appear surprisingly common.

Taha Yasseri@tahayasseri.bsky.social

Chapter 14: @bolozna.bsky.social on multilayer social networks. A great introduction to one of the most important recent developments in network science: moving beyond single-layer graphs to represent the multiple social contexts and relationships that shape human behavior. Social life is layered!

Hang-Hyun Jo
@socph.bsky.social

Since I got to know the MSE, I've wondered the mathematical relation between MSE and autocorrelation function (ACF) because both measure long-term temporal correlations. Of course they're different; the MSE is based on the entropy, while the ACF is not. I guess there must be some work on this topic.

Hang-Hyun Jo
@socph.bsky.social

I learned the Detrended Fluctuation Analysis (DFA) in the lecture on econophysics at KAIST in 2006, leading to a JKPS paper. And I coauthored a PLOS ONE paper in 2021 (doi.org/10.1371/jour...) where we applied the multiscale entropy (MSE) method to the temporal network time series data.

doi.orgImpact of environmental changes on the dynamics of temporal networksDynamics of complex social systems has often been described in the framework of temporal networks, where links are considered to exist only at the moment of interaction between nodes. Such interaction...
Hang-Hyun Jo
@socph.bsky.social

Complexity in time series were measured using various methods. Interestingly many of them show power-law behaviors. It's been known that the power-law exponents of power spectral density, autocorrelation function and Hurst exponent (which is itself a power-law exponent) are all connected.