December 8, 2010
By Erik Sherman | December 7, 2010
Wikileaks has yet another victim. This time, it isn’t the US government or the next expected target of a big leak,Bank of America, but Twitter. A number of sites like BoingBoingnoticed that Wikileaks didn’t appear on Twitter’s trending topics. Twitterdenied censorship and offered some explanations of its algorithmic approach to choosing trending topics.
But that was the problem. In a time of computers and automation, increasingly, software makes important decisions. Granted, programs use processes set by engineers, programmers, and scientists, but top management is generally uninvolved, even though applications may effectively direct the business in one way or another. Algorithms have become corporate factotums, trusted to work from approved guidelines at eye-crossing speed. But their complexity and intricacy of operations can have strategically important results that management cannot hope to follow, let alone control, and yet for which they are ultimately responsible.
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September 15, 2010
Perhatikan 4 baris pseudocode di bawah ini:
- MERGE-SORT A[1 . . n]
- If n= 1, done.
- Recursively sort A[ 1 . . [n/2]] and A[ [n/2]+1 . . n ] .
- “Merge”the 2sorted lists.
Memiliki cost dan effort:
- T(n)
- Θ(1)
- 2T(n/2) , Sloppiness: Seharusnya T(n/2) + T(n/2) , namun hal tsb bukan masalah secara asymptotic.
- Θ(n)
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September 14, 2010
Didalam internet dikenal IP Address
IP address hanya sebuah sarana untuk menunjukan lokasi sebuah alamat end point dalam topologi internet. Atau nama yang digunakan untuk identifikasi attachment point network layer.
Coba bandingkan bila anda akan mengirimkan email kepada teman anda antara menggunakan:
- ali@202.101.122.22
- ali@contoh.com
Tentu bila anda manusia, pasti akan memilih nomer 2.
Penggunaan IP address perlu mempertimbangkan:
- Kenyamanan & kemudahan
- Sesuai dengan contoh diatas perlunya perubah antara IP menjadi nama
- Perlunya sistem ter-modularisasi
- perlu ada satu sistem dan mekanisme terpisah yang mengurus hal distribusi nama tsb.
- Modularity yang mempertimbangkan faktor: skalabilitas dan reliabiltas.
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September 14, 2010
O-Notation , notasi O besar.
O(g(n)) = { f (n) : terdapat konstanta c and n0 sehingga 0 ≤ f (n) ≤ cg(n) untuk semua n ≥ n0} .
f(n) : fungsi n, adalah anggota dari kumpulan O(g(n)) atau kita bisa tuliskan f(n) ∈ O(g(n)).
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September 13, 2010
Berapa lama kita menjalankan kode atau fungsi di bawah ini ?
fungsi contoh(n):
print "ini contoh"
for i in range(n):
print "perulangan"+str(i)
