How to identify a strong vs weak relationship on ERD?

如何确定一个强与弱关系对Erd ？

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There was a weak relationship between circulating BNP and hemodynamics.

血浆BNP水平基本不受血流动力学变化影响。

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SR requires weak relationship between keys from the same sequence to keep an enough huge key space.

序列随机性要求构成密钥流的各密钥间具有弱相关性，以保证较大的密钥空间。

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As smart as this well known firm is, its inability to listen without defensiveness put a few more nails in the coffin of that already weak relationship.

FORBES: Five Things Rich Clients Hate About Their Advisors

There is a relationship between a weak yen and growth, but it's more tenuous.

WSJ: Business Asia: Unearned Praise for Abenomics

As a result of the impact of performance on attitudes, there often is a relationship, although a weak one, between satisfaction and performance.

FORBES: Engagement and Performance: Old Wine in a New Bottle