usb boot – USB bootable virtual machine creator

wanted to know if there is a bootable system that creates a virtual machine from an “offline system” resident in the local HD, and if there is a bootable core system to run virtual machines from external HDs.
I wanted to use an external HD to “clone” my current system, and be able to run the copied virtual instance of it with tampering with the physical one.
Did some research without much success.
Thanks in advance.

1-Tape Non-deterministic Turing machine and non-palindromes

I have to design a Non-deterministic 1-Tape Turing machine that accepts only non-palindromes in O (n log n).

But my best shot was only in O(n^2). How can I use the properties of NTM on a single tape to find a faster solution?

network – Secure a machine for pentesters

I’m trying to secure a Linux machine, that will eventually host many services, from penetration ie ( a pentester will not be able to exploit the machine in any way, shape, or form).

I know that there is no one answer to securing a machine or network from exploitation and that’s why we have pen-testers. However, if you can please guide me to books, references, and documentation that deals with securing machines and networks I would be grateful.

Thank you,

machine learning – Best algorithm/model to establish relevance between events utilizing mixed data type (Tags, Time, x_coordinate, y_coordinate)?

I’m building a relevance ranking system for incidents occurrence and prevention. My goal is to use four attributes to establish relevance: tag (About 500 tags), x_coordinate, y_coordinate and time. The final state that I would like to achieve is: to select an object and have a relevance list from the most relevant objects, that correlate to the one that I’ve selected, to the least relevant ones.

Ex.: I have a list of events such as event A that represents a fork-lift accident in x_c=5, y_c=7, 22:10:59, tag(“Crash”). event B (fork lift speeding at x_c = 3, y_c = 5, 22:10:11, tag(“Speeding”)). Event C (overheating on fork-lift 22:01:44, x_c=-4, y_c=-1, tag(“Mechanical Issue:Overheating”)). Now I select event A and then I get a list of the most relevant events related to event A, usually when you crash the fork-lift is because of high-speed, and they tend to be specially and timely near each other. Therefore, by selecting event A in my list of relevant events I get event B before event C in my list. The issue for me is that by encoding the tags I don’t know if I’m keeping them relevant for my model, and they are suppose to be very relevant…

The two different approaches that I used to achieve this goal were:

Multi-linear regression to create a correlation function between the objects. This works to a certain extent, the problem is to encode the tags in a way that doesn’t negatively influence the correlation.

Unsupervised learning, utilizing clustering and utilize the inertia between points to establish the relevance between the objects: low inertia=high relevance. Same issue here with the encoding, I must encode both labels and time-stamps (HH:mm:ss).

Please share your thoughts and let me know if there is any better approach or more optimal way of executing the approaches that I’m already using (I’ve wrote the scrips in python, so it’s easy and fast to make changes before implementing the final version in a different platform).

machine learning – Is it bad design to pass around a dictionary of arguments to all your functions?

In my machine learning pipeline, I have all the arguments collected into a dictionary.

args = {'save_model': True,
'learning_rate': 0.01,
'batch_size': 4,
'model': 'my_model',
'momentum': 0.9,
'random_brighness': 0.5,
'random_flipping': 0.5,
...}

Then I have a bunch of functions that take the entire args dictionary as an input. Each of these only uses a small subset of all the arguments. Is there anything wrong with this design?

model = get_model(args)
data = get_data(args)
transformed_data = transform_data(data, args)

from the perspective of the function, it looks like:

def get_trainer(args):
loss_function = args('loss_function')
optimizer = args('optimizer')
class_weights = args('class_weights')
...

versus:

def get_trainer(loss_function, optimizer, class_weights)
...

Which Virtual machine is used in Android 11?

Every android application runs in a virtual machine. We know that Dalvik virtual machine is the one that is used by android. Next, They have changed to ART(Android Runtime machine). Just correct me if I am wrong. Android 11 uses which virtual machine? Dalvik or ART?

backup – Samba/Avahi and changing permissions on Time Machine external drive

I recently decided to use my Time Machine external drive as a Raspberry Pi NAS and backup my data there. I’m using Samba and Avahi on latest Raspberry Pi OS. After setting everything up I’m still getting this Finder error when I’m trying to connect to it from my Macbook:

The operation can't be completed because the original item for "Backup Plus" can't be found.

I’m connecting as a samba enabled user.

My guess is that my mounting directory is owned by root instead of pi user. I want to change this but I’m not sure how filesystems work with permissions and I don’t want to mess up my backups (I still want an option to use the drive on Macbook directly). I’m using hfs+ on my drive.

Is it safe to change permissions on pi’s mounting point? Are the permissions stored in relation to the OS? Do they only affect mounting directory or are there any changes stored on drive itself? Is there a possibility to brake my existing backups when changing permissions? Maybe permissions are not the issue and there is another cause?

My smb.conf:

(Backup Plus)
    comment = Backups
    path = /media/pi/Backup Plus
    valid users = pi
    read only = no
    vfs objects = catia fruit streams_xattr
    fruit:time machine = yes

My avahi service:

<?xml version="1.0" standalone='no'?><!--*-nxml-*-->
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">
<service-group>
  <name replace-wildcards="yes">%h</name>
  <service>
    <type>_smb._tcp</type>
    <port>445</port>
  </service>
  <service>
    <type>_device-info._tcp</type>
    <port>9</port>
    <txt-record>model=TimeCapsule6,106</txt-record>
  </service>
  <service>
    <type>_adisk._tcp</type>
    <port>9</port>
    <txt-record>dk0=adVN=Backup Plus,adVF=0x82</txt-record>
    <txt-record>sys=adVF=0x100</txt-record>
  </service>
</service-group>

Is it possibe to launch a file on a remote windows machine PC?

I am currently copying a folder using winscp to a network machine. This folder has an exe file in it.
My question is if it is possible to launch that exe without actually remoting into that machine (i.e using remote desktop) ?

Does this Turing machine accept the following input: abcab

strong text
I’m trying to solve this Turing machine but so far I haven’t managed it. Does it accept the following input: abcab ?

Single tape Turing Machine that accepts string with at least five G’s and at most three T’s?

I am looking to create a single tape acceptor Turing machine acting upon the language of any ASCII string, that would only accept strings that contains at least five G’s and at most three T’s, and rejects any other ASCII string input. I am kind of stuck on how the machine would know that it had encountered greater than or equal to five G’s and less than or equal to three T’s.