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東京大学 情報理工学系研究科 創造情報学専攻 2006年8月実施 筆記試験 第4問

Author

itsuitsuki

Description

以下に示す情報システムに関する8項目から4項目を選択し、各項目を5~10行程度で説明せよ。必要に応じて例や図を用いてよい。

  1. 標本化定理(サンプリング定理)
  2. RISC 型と CISC 型プロセッサ
  3. インターネット・トランスポート層プロトコルの TCP と UDP
  4. ヒープソートのデータ構造(図で例を挙げて説明のこと)
  5. 関数型プログラミング言語の特徴
  6. 分枝限定法(例を用いて説明のこと)
  7. 自然言語の形態素(具体例を挙げて説明のこと)
  8. 同次座標系

Description (English)

Select four items out of the following eight items concerning information systems, and explain each item in approximately 5~10 lines of text. If necessary, use examples or figures.

  1. The sampling theorem
  2. RISC and CISC processors
  3. TCP and UDP as transport-layer protocols in the Internet
  4. The data structure used for heap sort (Explain with an illustrative example.)
  5. Features of functional programming languages
  6. Branch-and-bound algorithm (Explain with an example.)
  7. Morpheme in natural languages (Explain with examples.)
  8. Homogeneous coordinate system

Kai

RISC and CISC processors

RISC, i.e. reduced instruction set computer, is a type of processors keeping a minimal set of instruction. Complex operations here can be formed by smaller instructions. An example is RISC-V by UC Berkeley or ARM (Advanced RISC Machine) for Mac computers. Dominant architecture for embedded devices.

CISC, i.e. complex instruction set computer processor uses a complex set of instructions to cover various operations. An example is Windows x86/x64.

Branch-and-bound algorithm

Branch-and-bound algorithm is a classic algorithm in Operation Research (Numerical Optimization), typically to solve an integer programming problem. It repeats, for example, in an integer programming problem:

  1. Solving the relaxed problem (into real-valued), e.g. relaxing an IP into an LP;
  2. Bounding: Find the lower and upper bounds of the current problem. Take a minimizing problem as an example, the lower bound is the optimal value for the relaxed problem and the upper bound can be any objective value in the original problem;
  3. Branching, based on the solution, e.g. for a solution of the relaxation of with integer constraint, take (for example) as the branching variable, break the original IP into and where is plus a new constraint and is plus .
  4. Repeat solving (e.g. relaxed ), bounding and branching and end a subtree when a lower bound is also feasible for the original problem.