ubuntu – Why does Veracrypt show 2 partitions created?

I cleaned my Samsung 850 Evo 1TB SSD and only used veracrypt to complete the disk encryption with it. I also have another hard drive with which I have done this.

The HDD is sdb, and the EVO is sdc. The results resemble the following.

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For some reason, there are 2 partitions created for the Samsung SSD. When I want to mount sdb I use the command sudo veracrypt --mount / dev / sdb1, but when I want to mount sdc, I omit the drive letter and use the command sudo veracrypt --mount / dev / sdc, and the unit is assembled successfully. The df command even recognizes that the mount veracrypt has its total 1 TB of space.

So, why do I see 2 very large partitions created for this device?

general topology – $ C ^ infty $ atlas + Unit partitions $ Rightarrow $ Second accountant

Leave $ X $ Be a topological space (connected) with a $ C ^ infty $ atlas. It is a well-known theorem that if $ X $ He is the second accountant and Hausdorff, then admits unit partitions. I am trying to prove the "inverse" theorem:

Leave $ X $ Be a topological space (connected) with a $ C ^ infty $ atlas. Yes $ X $ Supports unit partitions, then $ X $ He is the second accountant and Hausdorff.

I was able to prove Hausdorff's condition by taking a partition of the unit $ { rho_p, rho_q } $ subordinate to $ {M – {p }, M – {q } } $ and taking neighborhoods $ U, V $ of $ p, q $ Small enough so that the values ​​of $ rho_p, rho_q $ in $ U $ conflict with those of $ V $ so that $ U cap V = emptyset $ Y $ U, V $ pull apart $ p, q $.

Now I'm stuck with the second accounting. Here is my intent:

For each $ p in M ​​$ take a graph $ varphi_p: U_p to mathbb {R} ^ n $. For a partition of the unit. $ { rho_p } $ subordinate to $ {U_p } $, leave:
$$ V_p: = rho_p ^ {- 1} (0, infty) subset U_p $$
By definition of unit partition, each $ q in X $ Belongs to finely many sets. $ V_ {p_1}, …, V_ {p_k} $, meaning $ {V_p } $ it's a finite local refinement of $ {U_p } $. Now from $ U_p $ is homeomorphic for $ mathbb {R} ^ n $, $ U_p $ He is the second accountant and therefore. $ V_p $ He is the second accountant.

I think the most natural thing is to find countless points. $ {p_n } _ {n in mathbb {N}} $ so that $ {V_ {p_n} } _ {n in mathbb {N}} $ It is a cover for $ X $, but I can not see how to do that.

partitions such that each $ k $ ($ 1 le k le n $) number appears at most $ k $ times

Leave $ lambda $ be a partition of $ n $ such that each number $ k $ ($ 1 le k le n $) appear at the maximum $ k $ times in $ lambda $.

For example : $ lambda = 6 + 6 + 6 + 6 + 3 + 2 + 2 + 1 $

Is there a special name for this type of partitions?

In addition, it is easy to write the generation function of these partitions
How do we have other types of partitions with restrictions?

If possible, please share some combinatorial importance of these partitions.

Thank you very much for your time.

Have a nice day.

Probability distributions: What is the minimum total coincidence distance expected between two partitions of points distributed identically and independently?

Bipartite match

Suppose a square $[0,1]times [0,1]$ in which $ N $ vehicles $ V_i $ Y $ N $ jockeys $ R_i $ they are distributed in an identical and independent way (for example, uniform distribution), a bipartite agreement (or a permutation, $ pi (i) $) is carried out between vehicles and passengers with the objective that the total distance

$$ Z = min _ { pi} sum_1 ^ N sqrt { Vert V _ { pi (i)} – R_i Vert ^ 2} $$

it is minimized.

Since the vehicle and passenger locations are distributed randomly, therefore $ Z $ It is a random variable. The expectation of $ Z $ It is therefore of interest. The question is how to derive the $ E (Z) $.

I found some related documents, such as

  1. Caracciolo, S., and Sicuro, G. (2015). Euclidean quadratic aesthetic
    bipartite match
    problem
    .
    Physical review letters, 115 (23), 230601.
  2. Holroyd, A.E., Pemantle, R., Peres, Y., and Schramm, O. (2009).
    Poisson
    pareo
    .
    In Annales de l & # 39; Institut Henri Poincaré, Probabilités et
    Statistics
    (Vol. 45, No. 1, pp. 266-287). Henri Institute
    Poincaré
  3. Boniolo, E., Caracciolo, S., and Sportiello, A. (2014). Correlation
    function for the Euclidean Grid-Poisson pairing in a line and in a
    circle
    . Diary of
    Statistical mechanics: theory and experimentation
    , 2014 (11), P11023.

I try to read them to find out how, but their derivation has a part very related to physics and statistical mechanics, which makes me try hard to understand it, but I do not get it.

I was wondering if there is a version with a flavor that does not require only physical-only-operations-research to solve this problem.

Using Linux to create / delete mac partitions

I'm trying to remove the malware on my computers and looking for the source of persistence *, I've tried different approaches, one to format the storage device with a table of mac partitions through Ubuntu. When I generate a new mac partition table, an unknown partition of 31.5kB appears, labeled / dev / sda1 but I can not do anything with it. Is this partition normal when implementing a mac partition table on a Linux platform?

* Malware remains after completing low-level formatting.

MySQL when using WHERE BETWEEN, the query reaches all the partitions

Probably this is just a misunderstanding about how MySQL partitions work, but I have a table defined with:

        `ID` int (11) NOT NULL,
`target_id` int (11) NOT NULL,
`created_at` datetime NOT NULL,

PRIMARY KEY (`ID`,` created_at`),
KEY `index_created_at_target_id` (` created_at` desc, `target_id`)
KEY `index_on_created_at` (` created_at`)
)
MOTOR = InnoDB DEFAULT CHARSET = utf8 COLLATE = utf8_unicode_ci
PARTITION FOR HASH (MONTH (`created_at`))
PARTITIONS 12

If you consult the data with only one Created in time stamp

select * on my_table where `created_at` = & # 39; 2018-12-00 05: 00: 00 & # 39; And target_id in (6,7,8);

Then the explanation knows that it should only hit 1 partition. This is correct.


However, if I ask in a range:

select * from my_table where `created_at` BETWEEN & # 39; 2018-12-00 05: 00: 00 & # 39; And & # 39; 2019-01-04 04: 59: 59 & # 39; And target_id in (6,7,8);

The explanation now hits all the partitions. Is this a known limitation, or am I just doing something wrong?


Note aside to judge by other questions of "partition", I hope that a couple of "partitions not only help to correctly index" the answers … I'm testing it myself and gathering some metrics to be able to find the best solution adapt to our needs. (Also the partition of the table, even when it then checks all the partitions, still reduces the query time by half compared to having 1 monolithic table with the same indexes: 2.3s vs. 0.8s)


Edition 1:

I made sure that both consultations reach the index_on_created_at index. The only difference is a "non-unique key search" versus an "index range scan" in the index.

MySQL when using WHERE BETWEEN, the query reaches all the partitions

Probably this is just a misunderstanding about how MySQL partitions work, but I have a table defined with:

        `ID` int (11) NOT NULL,
`target_id` int (11) NOT NULL,
`created_at` datetime NOT NULL,

PRIMARY KEY (`ID`,` created_at`),
KEY `index_created_at_target_id` (` created_at` desc, `target_id`)
KEY `index_on_created_at` (` created_at`)
)
MOTOR = InnoDB DEFAULT CHARSET = utf8 COLLATE = utf8_unicode_ci
PARTITION FOR HASH (MONTH (`created_at`))
PARTITIONS 12

If you consult the data with only one Created in time stamp

select * on my_table where `created_at` = & # 39; 2018-12-00 05: 00: 00 & # 39; And target_id in (6,7,8);

Then the explanation knows that it should only hit 1 partition. This is correct.


However, if I ask in a range:

select * from my_table where `created_at` BETWEEN & # 39; 2018-12-00 05: 00: 00 & # 39; And & # 39; 2019-01-04 04: 59: 59 & # 39; And target_id in (6,7,8);

The explanation now hits all the partitions. Is this a known limitation, or am I just doing something wrong?


Note aside to judge by other questions of "partition", I hope that a couple of "partitions not only help to correctly index" the answers … I'm testing it myself and gathering some metrics to be able to find the best solution adapt to our needs. (Also the partition of the table, even when it then checks all the partitions, still reduces the query time by half compared to having 1 monolithic table with the same indexes: 2.3s vs. 0.8s)


Edition 1:

I made sure that both consultations reach the index_on_created_at index. The only difference is a "non-unique key search" versus an "index range scan" in the index.

Real analysis – Intuition behind the integrability of Riemann and partitions sequences

I began to study the theory of measurements and, as a review, the book I am using (Rana) begins to explain some theorems about the Riemann integrals and I try to fully understand the intuition and proofs of the following theorem:

Leave $ f $ be an integrable function of Riemann in $[a,b]$, then there is a sequence of partitions. $ ( pi_n) _n $ such that $ pi_n subset pi_ {n + 1} $ for all $ n geq 1 $.

I'm not even sure how to start, besides realizing that f is Riemann integrable $ int_ {a} ^ {b} f (x) dx = sup {L ( pi, f) } = inf {U ( pi, f) } $ where $ pi $ it is a partition of $[a,b]$. Then we can choose $ ( pi_ {n} ^ {1}) _ {n}, ( pi_ {n} ^ {2}) n {$} such that $ lim $ $ U ( pi_ {n} ^ {1}, f) $=$ lim $ $ L ( pi_ {n} ^ {2}, f) = int_ {a} ^ {b} f (x) dx $ how n tends to $ infty $.

After that I'm stuck. Any help would be really appreciated.

After installing BootCamp I do not see partitions

After installing BootCamp mac does not show partitions:

Screenshot of the Bootcamp problem

But I can see them while I boot and in safe mode, also because of these problems I can not install new software and TouchID stopped working accidentally.

macos – Removing partitions in Mac OS

Please help. I tried installing Windows on Mac OS through boot camp. Windows could not install and now I have partitions that prevent me from reinstalling.

/ dev / disk0 (internal, physical):
#: SIZE IDENTIFIER NAME TYPE
0: GUID_partition_scheme * 251.0 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_APFS Container Disk1 104.0 GB disk0s2
3: Microsoft Basic Data OSXRESERVED disk0s6 8.0 GB
4: Apple_HFS BC2 69.9 GB disk0s4
5: Apple_HFS BC1 68.7 GB disk0s3

/ dev / disk1 (synthesized):
#: SIZE IDENTIFIER NAME TYPE
0: APFS Container Schema – 104.0 disk1 GB
Physical store disk0s2
1: APFS volume Macintosh HD disk1s1 49.1 GB
2: APFS pre-boot volume 22.3 MB disk1s2
3: APFS recovery volume 519.0 MB disk1s3
4: APFS Volume VM 11.8 GB disk1s4

/ dev / disk2 (disk image):
#: SIZE IDENTIFIER NAME TYPE
0: GUID_partition_scheme 42.7 MB disk2
1: Apple_HFS Git 2.18.0 Mavericks … 42.7 MB disk2s1

/ dev / disk3 (disk image):
#: SIZE IDENTIFIER NAME TYPE
0: CCCOMA_X64FRE_EN for the United States … 5.1 GB disk3

/ dev / disk4 (disk image):
#: SIZE IDENTIFIER NAME TYPE
0: GUID_partition_scheme 7.5 GB disk4
1: EFI EFI 209.7 MB disk4s1
2: Apple_HFS InstallESD 7.2 GB disk4s2