Grammar
N에 의한 + 명사
Meaning
AdvancedN e uihan + myeongsa
에 의한 is the noun-modifying form of 의하다, and it puts the source of something directly in front of the noun it produced: 폭우에 의한 피해 is 'damage caused by heavy rain'. Two kinds of source fit the slot. One is a cause, an event or condition that brought the noun about (지진에 의한 붕괴, 화재에 의한 사망). The other is an agent, the party that carried out the action the noun names (정부에 의한 조사, 법원에 의한 결정) — and this is the job 로 인해 does not do, because a typhoon can cause damage but a court does not 'cause' a decision, it makes one. Before a verb the same word appears as 에 의해, which is the standard way a 되다 passive names the doer it would otherwise leave out (연구팀에 의해 발표됐습니다). All of it belongs to written Korean — laws, reports, science and news writing — and none of it is said in conversation.
Form
Noun + 에 의한 in front of a noun, and noun + 에 의해 in front of a verb — the choice is made by what follows, not by meaning (폭우에 의한 피해, 폭우에 의해 무너졌다). Unlike 로/으로 there is no batchim rule to apply: 에 never changes shape, so 폭우에 의한 and 지진에 의한 are built the same way. The phrase attaches to nouns only; to feed a clause in, nominalise it first with -(으)ㄴ/는 것 (값이 오른 것에 의해) or switch to -기 때문에. 에 의하여 is the same form spelled out in full and is what statutes use. Note that 에 의하면 is NOT this pattern — it is the separate fixed expression meaning 'according to'.
Examples
폭우에 의한 피해가 남부 지역에 집중됐습니다.
Damage caused by the torrential rain was concentrated in the southern regions.
Common mistakes & nuance
The one thing worth carrying away is that 에 의해 marks the doer. Korean news runs on 되다 passives, which delete the agent on purpose (결과가 발표되었습니다 says nothing about who announced it); when the agent has to come back, 에 의해 is the slot it comes back into. So 위원회에 의해 발표됐다 names the committee as the announcer, while 위원회를 통해 발표됐다 only says the announcement travelled through it — the committee may have been a conduit for someone else's decision. Two smaller traps. 의한 and 의해 are chosen by what comes next, so 폭우에 의한 발생했습니다 and 폭우에 의해 피해 are both broken. And 에 의하면 looks like a member of this family but is not: it introduces the source of a REPORT ('according to'), not the source of an event, so reading 조사에 의하면 as 'caused by the investigation' inverts the sentence.
Similar grammar
- N(으)로 인해
The closest neighbour, and the two overlap wherever the source is a cause: 폭우에 의한 피해 and 폭우로 인한 피해 are both natural. They part company over agents. 로 인해 comes from 인하다 ('to be due to') and states a causal link, so it does not sit well in front of a deliberate act — 법원에 의한 결정 is normal Korean, 법원으로 인한 결정 is not. Where both fit, 로 인해 is the more common choice in news; where a person or institution DID the thing, 에 의한 is the one that works.
- N을/를 통해
Both can stand between an action and a named body, and they make different claims about it. 통해 marks the route the action travelled (온라인을 통해 신청하다, 위원회를 통해 발표되다); 에 의해 marks who performed it. The difference decides responsibility, which is why it matters in reporting: 대리인을 통해 제출됐다 leaves the submitter unnamed, while 대리인에 의해 제출됐다 says the agent is the one who submitted it.