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
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。
- 標本化定理(サンプリング定理)
- RISC 型と CISC 型プロセッサ
- インターネット・トランスポート層プロトコルの TCP と UDP
- ヒープソートのデータ構造(図で例を挙げて説明のこと)
- 関数型プログラミング言語の特徴
- 分枝限定法(例を用いて説明のこと)
- 自然言語の形態素(具体例を挙げて説明のこと)
- 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.
- The sampling theorem
- RISC and CISC processors
- TCP and UDP as transport-layer protocols in the Internet
- The data structure used for heap sort (Explain with an illustrative example.)
- Features of functional programming languages
- Branch-and-bound algorithm (Explain with an example.)
- Morpheme in natural languages (Explain with examples.)
- 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:
- Solving the relaxed problem (into real-valued), e.g. relaxing an IP into an LP;
- 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;
- 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 . - Repeat solving (e.g. relaxed
), bounding and branching and end a subtree when a lower bound is also feasible for the original problem.