Personal Blogs
ARGUMENT MAPPED ATTEMPT (RUDENESS)
Thursday, 4 Jun 2020, 22:59
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https://www.theguardian.com/lifeandstyle/2012/feb/10/this-column-change-your-life-rudeness
Trying to dissect an article on rudeness, to practise my argument mapping skills.
Attachments:
Just going over some basic Java in preparation fror one of my Modules "M250"
Saturday, 30 May 2020, 19:55
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Using ticket machine class to print a ticket in Java
Growth Mindset
Friday, 22 May 2020, 14:20
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Carol Dwek - thank you 
A 'Growth mindset', simple, powerful, should be at the core of every students thought process.
Something which I've been wondering about for years and had confirmed is the difference between a 'fixed' and 'growth' mindset.
New Online Student Support :)
Sunday, 26 Apr 2020, 16:28
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Edited by George Muirhead, Sunday, 26 Apr 2020, 16:34
Excellent websites
Wednesday, 22 Apr 2020, 21:41
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Edited by George Muirhead, Saturday, 25 Apr 2020, 08:56
Disinformation in a time of crisis
Sunday, 22 Mar 2020, 14:40
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Edited by George Muirhead, Thursday, 18 Jun 2020, 06:15
In a time of such unprecedented measures being imposed on the global population, I came across a few pieces of very poignant observation, which I think everyone could benefit from, before making uninformed comments about Corona Virus Disease 2019, (previously known as “2019 novel coronavirus”)
There is no treatment for it, despite all the rubbish you read on social media,"There's so much noise, everybody wants to have a point of view." (Stephen Fry, 2020), it's the 'experts', people should be listening too, not ill-informed panicky jittery rubbish proliferated on social media,
"But the fact is, if you listen to the scientific advisers, they almost always begin every sentence, with, 'we think', 'it's possible', 'maybe',
'perhaps', 'we don't know, but', that's how experts talk, people who really understand it."
(Stephen Fry,2020) —
"Prof Christine Jenkins, chair of Lung Foundation Australia and a leading respiratory physician, told Guardian Australia: At the moment there isn’t any established treatment apart from supportive treatment, which is what we give people in intensive care.
" (Graham Readfearn, 2020)
"Experts, like the rest of us, have no access to infallible truths in unprecedented crises. The stakes could scarcely be higher, but the scientific bets being laid involve judgments, not certainties.
The government, advised by Sir Patrick and Prof Whitty, believes that drastic action to suppress coronavirus could store up bigger problems down the line, when measures are relaxed. Therefore, they judge the least-worst outcome for the country will be a managed epidemic which peaks gradually, so that the NHS is not overwhelmed, and creates “herd immunity” to what could become an annual virus. There is also concern that forcing people into more isolated lives too soon could be counterproductive. Sir Patrick has predicted that the epidemic’s peak in Britain could still be 10 to 14 weeks away; too much isolation too soon could lead to coronavirus “fatigue”, causing people to revert to old ways at precisely the wrong moment."
(https://www.theguardian.com/commentisfree/2020/mar/13/the-guardian-view-on-science-and-coronavirus-no-certainties-just-judgments,2020)
https://www.bbc.co.uk/news/av/uk-51995797/coronavirus-stephen-fry-s-take-on-managing-anxiety
References:
Readfearn, Graham. (2020) ‘Coronavirus: what happens to people's lungs when they get Covid-19?', Guardian, 22 March[Online]. Available at https://www.theguardian.com/world/2020/mar/22/coronavirus-what-happens-to-peoples-lungs-when-they-get-covid-19(Accessed 22 March 2020).
BBC (2020) BBC News [Online]. Available at https://www.bbc.co.uk/news/av/uk-51995797/coronavirus-stephen-fry-s-take-on-managing-anxiety
(Accessed 22 March 2020).
Cross-collaterization
Wednesday, 18 Mar 2020, 14:02
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GNU and the history of recursive acronyms
Monday, 16 Mar 2020, 12:16
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GNU is a recursive acronym for "GNU's Not Unix!",chosen because GNU's design is Unix-like, but differs from Unix by being free software and containing no Unix code.
A recursive acronym is an acronym that refers to itself. The term was first used in print in 1979 in Douglas Hofstadter's book Gödel, Escher, Bach: An Eternal Golden Braid, in which Hofstadter invents the acronym GOD, meaning "GOD Over Djinn", to help explain infinite series, and describes it as a recursive acronym.
Phenomenal Podcasts
Wednesday, 4 Mar 2020, 14:55
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Edited by George Muirhead, Wednesday, 4 Mar 2020, 14:57
Future talks, fascinating podcasts
https://podcasts.ox.ac.uk/series/futuremakers
Hyperscale
Saturday, 29 Feb 2020, 15:45
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Edited by George Muirhead, Saturday, 29 Feb 2020, 15:45
Great word, just heard it for the first time
https://en.wikipedia.org/wiki/Hyperscale_computing
Thinking about SALT and HASHING
Thursday, 6 Feb 2020, 16:32
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My understanding of hashing and salting, and the process:
Things to remember:
It's used to guard against dictionary attacks
it's used to thwart brute force attacks
Process:
1 Salt is generated:
[usually in proportional length] relative to the SHA being deployed.
The hash value is generated.
The salt is added to the beginning of the hash value.
The salt is added to the end of the hash value.
Remember: Binary is base 2
Explanation and Example: 2-bit salt
The number of bits is in relation to the number of binary bits [1's and 0's] contained within each little binary container.
This means each little binary container
[contains within it]
2 to the power of 2, thus:
00 01 10 11
Now 2 to the power of 2 is equal to 4
So this 4 — is equal to the total number of little binary containers .
So a picture like this is perhaps clearer:
Binary bits — 00 01 10 11
Binary containers — 1 2 3 4
The total number of possible values this can create:
Is directly related to the number of times each binary container [ which contains the binary bits]
can be added to the front of the hashed value
and to the end of the hashed value :
So there this would mean there are a total of
2 to the power of 4 possible combinations
2 to the power of 4 is equal to 8
So to sum up:
when thinking about bits :
This is the number of bits contained within each binary container
When thinking about the resulting total number of possible binary combinations:
This is the total number of possible combinations
and can be worked out using base 2 to the power of the desired number of bits.
What lies ahead
Friday, 31 Jan 2020, 13:22
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Edited by George Muirhead, Friday, 31 Jan 2020, 13:26
I'm officially on holiday for 2 weeks from tomorrow — finally it gives me the chance to be relaxed, focused and think about all the great material I've overlooked and rushed through.
This is probably an obvious point to many people — it's only now I'm beginning to realise why a lot of study advice keeps reiterating —take lots of short breaks, don't try to process too much information in one go.
The thoughts need to absorb your subconscious cognitive processes for one to truly understand concepts.
Automation
Thursday, 30 Jan 2020, 11:58
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The differences between Classful and Classless Subnet Masks
Tuesday, 28 Jan 2020, 14:45
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Why are classful subnet masks of a fixed length wasteful?
Because when you want to subnet your network,
you are constrained by doing it in powers of 2.
That is either 2,4,8,16,32,64,128 etc.
This is one of the reasons for changing to a classless addressing scheme, this means your subnet mask can be a variable length.
Which means your can subnet your network precisely to the required number of required subnetworks.
Classful Subnetting with IPV4 Addresses
Sunday, 26 Jan 2020, 11:24
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I just typed ipconfig /all into the cmd.
The following was returned
Connection-specific DNS Suffix . : lan
Description . . . . . . . . . . . : Broadcom 802.11n Network Adapter
Physical Address. . . . . . . . . : 74-E5-43-7D-8B-65
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::39d0:ff36:ff66:2215%15(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.78(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : 26 January 2020 07:13:40
Lease Expires . . . . . . . . . . : 27 January 2020 07:13:40
Default Gateway . . . . . . . . . : 192.168.1.254
DHCP Server . . . . . . . . . . . : 192.168.1.254
DHCPv6 IAID . . . . . . . . . . . : 259319107
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-25-1D-01-86-D4-BE-D9-53-C6-37
DNS Servers . . . . . . . . . . . : 192.168.1.254
I know it's beyond the scope of this module, that is subnetting;
My IPv4 Address is 192.168.1.78
I have a subnet mask of 255.255.255.0 --> this is a network, network, network. host pattern
which means I'm on the 192.168.1.0 network.
now if I had a subnet mask of 255.255.255.240 what do you think this means?
Answer:
I think it means I've sub-netted my default subnet mask, I've taken or stolen binary bit's from the octet host portion of my IPv4 address.
This means more networks but at a cost of less hosts.
This means in effect we are creating smaller subnetworks out of the larger one, dividing it up .
But realising that although you will increase the amount of networks, each range will hold a smaller amount of hosts per subnetwork.
how many bits did I steal to do this?
Answer:
convert the custom subnet dotted decimal host portion to binary,
128 64 32 16 8 4 2 1 - binary values working
1 1 1 1 0 0 0 0 240 - 128 = 112
112 - 64 = 48
48 - 32 = 16
16 - 16 = 0
check: 128 + 64 + 32 + 16 = 240
111100002 = 24010 (denary value)
This means 4 bits where taken from the host octet portion of the IPv4 address.
next question :
How many usable new subnetworks does this give me?
to work this out :
use formula : Number of subnets = 2s
so 24 = 16 so 16 subnets.
How many hosts per subnet ?
use formula : Number of hosts per subnet = 2h -2
I originally had 8 bits in the host portion and 8 - 4 = 4
so 24 - 2 = 14
Total number of subnets (subnetworks) = 16
Total number of host address per subnetwork = 14
workout the difference in binary between the default network address binary number and the
custom subnetwork binary number: ( Note the count starts at 0 !)
Address Ranges per subnetwork
(0) 192.168.1. 0 0 0 0 . 0 0 0 0 192.168.1.0 - 192.168.1.15
(1) 192.168.1. 0 0 0 1 . 0 0 0 0 192.168.1.16 - 192.168.1.31
(2) 192.168.1. 0 0 1 0 . 0 0 0 0 192.168.1.32 - 192.168.1.47
(3) 192.168.1. 0 0 1 1 . 0 0 0 0 192.168.1.48 - 192.168.1.63
(4) 192.168.1. 0 1 0 0 . 0 0 0 0 192.168.1.64 192.168.1.79
(5) 192.168.1. 0 1 0 1 . 0 0 0 0 192.168.1.80 - 192.168.1.95
(6) 192.168.1. 0 1 1 0 . 0 0 0 0 192.168.1.96 - 192.168.1.111
(7) 192.168.1. 0 1 1 1 . 0 0 0 0 192.168.1.112 - 192.168.1.127
(8) 192.168.1. 1 0 0 0 . 0 0 0 0 192.168.1.128 - 192.168.1.143
(9) 192.168.1. 1 0 0 1 . 0 0 0 0 192.168.1.144 - 192.168.1.159
(10) 192.168.1. 1 0 1 0 . 0 0 0 0 192.168.1.160 - 192.168.1.175
(11) 192.168.1. 1 0 1 1 . 0 0 0 0 192.168.1.176 - 192.168.1.191
(12) 192.168.1 1 1 0 0 . 0 0 0 0 192.168.1.192 - 192.168.1.207
(13) 192.168.1 1 1 0 1 . 0 0 0 0 192.168.1.208 - 192.168.1.223
(14) 192.168.1 1 1 1 0 . 0 0 0 0 192.168.1.224 - 192.168.1.239
(15) 192.168.1 1 1 1 1 . 0 0 0 0 192.168.1.240 - 192.168.1.255
So to conclude there are a total of 16 subnets or 16 subnetworks, that counting from 0 to 15 which is like the range function in python index starting at 0 !
Within each subnetwork division there are 14 usable host addresses
this is because each sub-network's starting address
per pool of IPv4 addresses is the address of that subnetworks address itself ! ( the lowest IPv4 address)
and the highest value address per pool of subnet-work addresses is that subnetwork's broadcast address.
super-netting is the opposite more hosts but at cost of less networks.
Problem Types Booleans, Iteration and selection.
Tuesday, 21 Jan 2020, 18:53
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Types of problem:
- Numeric problems -> the output is directly determined by the input.
Analyse multiple casesMultiple cases
Patterns Problem
TypePattern
UsePattern
NumberProblem
ClassNumeric Formula 4.1 Numeric Case
analysis (two cases)4.2 Numeric 4.3 Numeric Nested cases 4.4 Numeric Generate a sequence 4.5 Numeric Generate a list 2.1 Numeric Append to a list 2.2 Numeric Filter list 2.3 Numeric List Tranformation 2.4 Numeric Reduce 2.5 Counting
problemsNumeric Aggregate 2.6 Counting
problemsNumeric Search 2.7 Find a value Numeric Search 2.8 Find best value
- Calculate
- Formula problems
- Word problems
- Formula problems
- Case analysis
- Two Cases
- Multiple Cases
- Nested Cases -> efficient
- Generate a sequence
- Initialise and generate
- Terminatation condition - > Give a suitable condition to stop the generation
- Non-termination -> Under which conditions will the generation never stop ?
- Infinite loops
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