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5:06 AM
@MartinSleziak The tag is now gone, as the question [was deleted](math.stackexchange.com/posts/3263192/revisions0.
@MartinSleziak The tag no longer exists, it was removed soon after being created.
@MartinSleziak The tags and tag:similarity-dimension are gone, too.
@MartinSleziak The tag has grown to five questions, but it seems that it is used for various questions - ranging from calibrated geometry to a question how to calibrate a camera.
Let me just post a sample of the questions from this tag into this room - I will then remove the feed.
The mathematical field of differential geometry, a calibrated manifold is a Riemannian manifold (M,g) of dimension n equipped with a differential p-form φ (for some 0 ≤ p ≤ n) which is a calibration, meaning that: φ is closed: dφ = 0, where d is the exterior derivative for any x ∈ M and any oriented p-dimensional subspace ξ of TxM, φ|ξ = λ volξ with λ ≤ 1. Here volξ is the volume form of ξ with respect to g.Set Gx(φ) = { ξ as above : φ|ξ = volξ }. (In order for the theory to be nontrivial, we need Gx(φ) to be nonempty.) Let G(φ) be the union of Gx(φ) for x in M. The theory of calibrations is...
I will also mention that the tag-info for calibrations is empty.
Queries which show also editors who added/removed the tag: data.stackexchange.com/math/query/1105163/… data.stackexchange.com/math/query/1038474/…
Jun 19 '19 at 19:41, by Arctic Char
A naive search of the term calibration in MSE returns around 160 results. I checked the most recent 50 posts, only 3 of them are about calibrations in RG.
Jun 19 '19 at 19:46, by Arctic Char
More are about Camera calibration (in projective geometry) and some in stochastic DE.
5:32 AM
Q: Calibrations vs. Riemannian holonomy

rmdmc89I've began to study the relationship between calibrations and holonomy, mainly through D.D. Joyce's Riemannian Holonomy Groups and Calibrated Geometry and partly through internet material. Pretty much everyone explains this relationship by the holonomy principle: if $H=\text{Hol}_x$ and $\varp...

Q: Question on concept of homology in calibrated geometry

deepfloeThe fundamental lemma of calibrated geometry states that calibrated submanifolds are absolutely volume minimising in their homology class. In the proof, homology equivalent is used synonymously with cobordant. With respect to which homology theory are they minimising? Are they volume minimising w...

Q: To 3D world point with height instead of depth estimate

DerkI am reading the paper "Unsupervised Learning of Depth and Ego-Motion from Video" (https://people.eecs.berkeley.edu/~tinghuiz/projects/SfMLearner/cvpr17_sfm_final.pdf) Equation 2 of this paper is as follows: $$p_s \approx K\hat{T}_{t\rightarrow s}\hat{D}(p_t)K^{-1}p_t$$ It projects a pixel in t...

Q: What is the derivation for the targets used in Platt Scaling?

bashmikeIn the original Platt Scaling paper [1], the target probabilities used to calibrate a model's non-probabilistic outputs are found to be: $$t_+ = \frac{N_+ + 1}{N_+ + 2} \qquad t_- = \frac{1}{N_- + 2} $$ How are these, as the paper says, max a posteriori estimates? (What are the prior, likeliho...

Q: camera calibration problem - computer vision

plsHelpI am new to computer vision and I have a problem which may not require a complex algorithm, however im not sure if I have enough data to ignore this. problem statement: I have a 6-joint robot arm and a 3D camera with trackers. With these trackers I can obtain the homogenous transformation matri...

Martin Sleziak has stopped a feed from being posted into this room
I have added the tag to one more question:
Q: Verify a two-form is calibration

lanse7pty$u: \Omega \subset \mathbb R^2 \rightarrow \mathbb R$ is a $C^2$ function. Graph of $u$ is $$ G_u=\{(x,y,u(x,y)) : (x,y)\in \Omega\} $$ And the upward pointing unit normal is $N$. $\omega$ is the two-form on $\Omega\times \mathbb R$ given by that for $X,Y\in \mathbb R^3$ $$ \omega(X,Y) = \det (X...

5:46 AM
A: Tag management 2020

Martin SleziakRename calibrations to calibration-geometry. The tag calibrations was created in June 2019. This is the question where the tag was created: Calibrations vs. Riemannian holonomy. From this question it seems that the intention was to created a tag for calibrated geometry. As the tag name can be in...

3 hours later…
8:53 AM
@MartinSleziak The tag no longer exists, the question was deleted: math.stackexchange.com/posts/3278293/revisions
@MartinSleziak The tag is gone, too.
Queries which show also editors who added/removed the tag: data.stackexchange.com/math/query/1105163/… data.stackexchange.com/math/query/1038474/…
I see that in one of those questions it was created and removed twice: math.stackexchange.com/posts/3238019/revisions
9:29 AM
A: Tag management 2019

YuiTo ChengProposal to remove (or even blacklist) significance It is a meta tag and it is a bad one. I sincerely ask the creator to stop retagging old questions until we have an actual discussion.

2 hours later…
11:50 AM
@MartinSleziak The question was deleted, so si gone.
@MartinSleziak The tag is no longer available on the site, the question was closed and deleted.
@MartinSleziak Since that question was deleted, the tag no longer exists.
4 hours later…
3:56 PM
I don't think this is an appropriate way to use the tag [proof-explanation]: math.stackexchange.com/posts/3667847/revisions
"Edit approval overridden by post owner or moderator".
7 hours later…
11:17 PM
A: Tag management 2020

Martin SleziakRename calibrations to calibrated-geometry. (Also a name such as (calibrations-differential-geometry) - or something similar - would help with clarifying the content of the tag. However, that seems to be unnecessarily long.) The tag calibrations was created in June 2019. This is the question whe...

A possible alternative would be to removed the tag for callibrations (or callibration geometry) completely, if users more experienced in this area consider the tag unlikely to be useful. — Martin Sleziak 18 hours ago
Not sure if it is calibrated geometry or calibrated geometries. The latter one is used in the oriiginal papers where calibration was introduced. There are several different such geometries. — Arctic Char 3 hours ago

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