Тема 12. Структуризація великих мереж

THE COMMUNICATIVE APPROACH

THE TOTAL PHYSICAL RESPONSE METHOD

Total Physical Response (TPR) is a language teaching method built around the coordination of speech and action; it attempts to teach language through physical (motor) activity. Developed by James Asher, a professor of psychology at San Jose State University, California, it draws on several traditions, including developmental psychology, learning the­ory, and humanistic pedagogy, as well as on language teaching proce­dures proposed by Harold and Dorothy Palmer in 1925. Let us briefly consider these precedents to Total Physical Response.

Lessons in TPR are organized around grammar, and in particular around the verb. Instructors issue commands based on the verbs and vocabulary to be learned in that lesson. However, the primary focus in lessons is on meaning, which distinguishes TPR from other grammar-based methods such as grammar-translation. Grammar is not explicitly taught, but is learned by induction. Students are expected to subconsciously acquire the grammatical structure of the language through exposure to spoken language input, in addition to decoding the messages in the input to find their meaning. This approach to listening is called codebreaking. Total physical response is both a teaching technique and a philosophy of language teaching. Teachers do not have to limit themselves to TPR techniques to teach according to the principles of the total physical response method.

Because the students are only expected to listen and not to speak, the teacher has the sole responsibility for deciding what input students hear.

Communicative language teaching (CLT), or the communicative approach, is an approach to language teaching that emphasizes interaction as both the means and the ultimate goal of study.

Communicative language teaching makes use of real-life situations that necessitate communication. The teacher sets up a situation that students are likely to encounter in real life. Unlike the audiolingual method of language teaching, which relies on repetition and drills, the communicative approach can leave students in suspense as to the outcome of a class exercise, which will vary according to their reactions and responses. The real-life simulations change from day to day. Students' motivation to learn comes from their desire to communicate in meaningful ways about meaningful topics.

В невеликих мережах (10-30 комп’ютерів) найчастіше використовується певна типова топологія:

· Загальна шина (Ethernet).

· Зірка (Ethernet).

· Кільце (TokenRing, FDDI).

Всі ці топології мають властивості однорідності – тобто всі комп’ютери у мережі мають однакові права на доступ до інших комп’ютерів. Однорідність структури спрощує нарощення числа комп’ютерів, полегшує обслуговування та експлуатацію мережі.

При розбудові великих мереж виникають певні проблеми:

· Обмеження на довжину ліній між вузлами.

· Обмеження на кількість вузлів.

· Обмеження на інтенсивність трафіку.

Для вирішення цих проблем використовують спеціальні методи структуризації мереж та спеціальне обладнання:

· Повторювачі (repeater).

· Концентратори (concentrator, hub).

· Мости (bridge).

· Комутатори (switch).

· Маршрутизатори (router).

· Шлюзи (gateway).

Таке обладнання називається комунікаційним, бо воно призначено для об’єднання окремих сегментів мережі до єдиного цілого.

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