Propagator

More often than not, people are too concerned with solving problems and not exactly interested in the processes that derives the solutions to these problems. I was working on the ‘quiz’ on Kwang Guan’s blog, which I shall reproduce below:

“Below is a quiz written by Einstein last century.
It’s been translated and updated since then, but the logic is still the same. He said 98% of the people in the world can’t solve the quiz. Are you among the other 2%?”

Facts:
1. There are 5 houses in 5 different colors
2. In each house lives a person with a different nationality.
3. These 5 owners drink a certain type of beverage, smoke a certain brand of cigar, and keep a certain pet.
4. No owners have the same pet, smoke the same brand of cigar or drink the same drink.

Hints:

1. The Brit lives in a red house

2. The Swede keeps dogs as pets

3. The Dane drinks tea

4. The green house is on the left of the white house

5. The green house owner drinks coffee

6. The person who smokes Pall Mall rears birds

7. The owner of the yellow house smokes Dunhill

8. The man living in the house right in the middle drinks milk

9. The Norwegian lives in the first house

10. The man who smokes Blend lives next door to the one who keeps cats.

11. The man who keeps horses lives next door to the man who smokes Dunhill

12. The owner who smokes Blue Master drinks beer

13. The German smokes Prince

14. The Norwegian lives next to the blue house

15. The man who smokes Blend has a neighbor who drinks water

The question is: Who keeps fish? Try to work this out at the blank space below. Good luck!”

I told Kwang Guan that I took some time to solve it using Notepad on my computer. He declared that Anne (Marie, I’ll assume) and De Ren solved it quickly using Excel Spreadsheet. He personally preferred using what he claims to be a piece of paper, a pen and logic. I replied that the logic he is referring to, is basically elimination. I’m immediately a little intrigued by my own exclamation. I wonder how I actually solved the question; at that time it was partial guess and part trying to ‘fill in the blanks’ (which I believe was what Anne and De Ren did). I therefore decided to write about how my mind treated the ‘hints’ to eventually arrived at the answer.

The simplest way of looking at it is to adopt the rows & columns method with the rows placing the different traits: House Color, Nationality, Cigarette Brand, Drink and then Pets. Then the columns includes everything falling under the same house.

There’s little point in reading the hints sequentially, I decided to throw in all the possible values and then move them around according to the hints. I read through everything and jot down all the types of each traits:

After throwing everything into the grid with best effort to adhere by the hints; notice I try to fit the information provided directly by a single hint together as far as possible. Now make use of those hints that supplies information about the positions and tie them up together with the directly linked information:

After obtaining the first table, we identify the conflicts between the table and what is stated. Essentially when a hint ties up 2 things together, it’s like forming an odd-shaped piece of a puzzle to be fitted into the grid; interestingly, when a hint that ties up 2 things that each already have another trait tied to it by other hints would all together form a bigger piece of the odd shape. This process allows us to fit bigger pieces into the grid and then examine the remaining pieces.

Eventually we have everything on the grid except the ‘Fish’ which is then identified under the ‘German’. There we got our answer. It’s hard to describe the ‘working’ for this question because it entails continually working on the hints, synthesizing information and thus filling up the grid. A stepwise dictation of the method would be impractical in conveying the treatment of this question. I’m essentially describing a means by which we can try to organize the various data to achieve the solution.

Somehow this is a bit like Sudoku except the hints govern the placement of the different traits…

It’s been a darn long time since I last blogged because I’ve been rather busy with university matters, army matters and a substantial amount of time is devoted to perfecting the art of dodging arrows. I’m still pretty lousy at it since I find myself compelled to be busy and to carry out my basic duties as far as possible.

I am blogging because I feel an urge to talk about my experience with fiddling with my wireless router. After being in signals for a while I figured out I should at least play around with my home router with whatever I learnt. It’s just securing the home network but somehow it is more fun when you apply things that are somehow related to your work back at home. My home network was freaking unsecured actually, and I’m absolutely aware of that. First I use the lousiest and the most basic encryption keys available for wireless networks, next I use the default SSID (and broadcast it as well); finally, I do not use any sort of filtering on my network. You pros out there must be quite sad you didn’t chance upon my network to leech upon but then again my router is a pathetic little wireless signal transmitter that cannot cover much area anyways.

So to cover up all the security flaws in the home network, I took some time to reconfigure it, changed the SSID (attempted with the disabling of broadcast but ultimately decided to turn it back on), changed the encryption system and finally, I added MAC address filtering which will totally shut any illegal users out from using the Internet through my line. I’m not going to be talking about how to do it, but in general, just try to figure out how to get those stuff done in order to step up network security, especially for wireless. A point to note is about securing console access. MAC address filtering is the most foolproof way of securing network to prevent people from stealing your Internet and the thing about it is that the only way for ‘hackers’ to get around this problem is to console into your router and turn off the MAC filtering. Therefore, you should disable the remote console access (ie. turn off the telnet port, which is Port 23) if it’s not necessary and for consumer-end routers where you don’t even know what I mean by ‘console into your router’, you could try changing your router IP to something besides the default one – I’m pretty sure the option is available on your web-based configuration panel. Finally, whether you can access the remote console or not, you should set a proper, decent, difficult-to-crack password for the configuration authentication.

After doing all that, you’ll start feeling rather accomplished because you just kept out the thousands of neighbours (especially when you are living in the new type of HDB flats with 40 storeys and you happen to be on the 21 floor, and the buildings are built so close to each other you can even access the wireless network of someone 2 blocks away plus you bought yourself a tough-looking router that sends out signal within a 500m spherical radius) who were previously leeching on your Internet without you knowing. How wonderful, now you can enjoy the full bandwidth of Internet you paid for.

On other matters, I got Kwang Guan to help me buy a EP-630 earphones from Comex. It’s not exactly much cheaper but those earphones are decent enough in terms of sound quality (I don’t quite agree with their claims of deep bass) and noise isolation. I think I’m planning to get earphone adapters though I haven’t quite figure out if I’m going to stick to Sony Ericsson after ORD.