2025 대학수학능력시험 9월 모의평가 듣기 16-17

Good morning, students. Today, we’re going to learn about the key characteristics that enable some animals to reach high speeds. First, there’s no animal faster on land than the cheetah. Its flexible backbone and joints allow for extreme extension, enabling it to stretch its legs very far and push off its back legs with great force like a spring. Second, the falcon is one of the fastest birds. Its large breastbone allows more muscle to be attached to it, so it can beat its wings with greater power. Third, the swordfish is among the fastest fish in the sea. It releases a special, slippery oil from its head that coats the front of its body, enabling it to swim with less resistance. Lastly, the dragonfly is considered the world’s fastest flying insect. It has the unique ability to slightly twist its wings as they swing down, causing a small tornado-like wind that gives it a boost of speed. Now, let’s watch a video of nature’s speedsters.
*breastbone: 흉골, 가슴뼈 
*coat: ~에 칠하다, 웃옷을 입히다

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Install and run an FTP server using Docker

To install and run an FTP server using Docker, follow these steps. We’ll use the popular stilliard/pure-ftpd image, which is a lightweight and widely used FTP server. Step 1: Install Docker Make sure Docker is installed on your machine. If it isn’t, install it using the instructions below: Ubuntu/Debian: sudo apt update sudo apt install docker.io -y Mac: Install Docker Desktop from Docker's website . Windows: Install Docker Desktop from Docker's website . Verify Docker is installed: docker --version Step 2: Pull the FTP Server Docker Image Use the stilliard/pure-ftpd image, which is a simple and effective FTP server. docker pull stilliard/ pure -ftpd Step 3: Run the FTP Server Run the FTP server container using the following command: docker run -d --name ftp-server \ - p 21 : 21 -p 30000 - 30009 : 30000 - 30009 \ - e FTP_USER_NAME=testuser \ - e FTP_USER_PASS=testpass \ - e FTP_USER_HOME= /home/testuser \ stilliard/pure-ftpd Explanation...
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To switch to a specific tag in a Git repository

To switch to a specific tag in a Git repository, you can use the git checkout or git switch command. Here's how you can do it: 1. List Available Tags First, you may want to see a list of all available tags in the repository: git tag 2. Checkout a Specific Tag Once you know the tag you want to switch to, you can use either git checkout or git switch (if you're using a newer version of Git, which recommends git switch for checking out branches). Using git checkout : git checkout <tag- name > Using git switch (recommended for newer versions of Git): git switch -- detach <tag- name > The --detach flag is necessary because tags are not branches; they are just pointers to specific commits. Using --detach makes your HEAD point to the tag without modifying any branch. 3. Verify the Checkout After switching to the tag, verify that you're on the correct commit: git status This will show the tag you're currently on (you'll see somethi...
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MAX_POLL_RECORDS_CONFIG in Kafka

The default value of MAX_POLL_RECORDS_CONFIG in Apache Kafka is: 500 What is MAX_POLL_RECORDS_CONFIG ? The MAX_POLL_RECORDS_CONFIG configuration specifies the maximum number of records a Kafka consumer can retrieve in a single call to the poll() method. Key Details: Default Behavior : If not configured, the consumer will fetch up to 500 records per poll. This is a batch size limit and helps in controlling the volume of data processed at a time. Adjusting the Value : Smaller values (e.g., 10 ): Useful for low-latency processing or when you want to process fewer records at a time. Larger values (e.g., 1000 ): Useful for batch processing or applications designed to handle high throughput. Use Case Scenarios : High throughput: Increase the value to minimize the number of poll() calls. Low latency or real-time processing: Decrease the value to process smaller chunks faster. Example Configuration Java Configuration: Properties props = new Properties(); p...
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Using the MinIO API via curl

Using the MinIO API via curl is straightforward, as MinIO is compatible with Amazon S3 API, so most commands follow a similar syntax. Here’s a guide on how to use curl with the MinIO API for some common operations like uploading, downloading, and managing objects. Prerequisites Access Key and Secret Key : Obtain your MinIO Access Key and Secret Key. MinIO Endpoint : Know your MinIO server endpoint, e.g., http://localhost:9000 . Bucket : You may need an existing bucket name, or create a new one using the commands below. Authentication Header For requests to work with MinIO, you need to include authentication in the headers. MinIO uses AWS Signature Version 4 for signing requests. Common Examples 1. List Buckets To list all buckets in your MinIO account, use: curl -X GET \ - -url "http://localhost:9000/" \ - H "Authorization: AWS <AccessKey>:<Signature>" 2. Create a Bucket To create a new bucket, use: curl -X PUT \ - -url "htt...
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How to checkout branch of remote git, 깃 리모트 브랜치 체크아웃

To check out a branch from a remote Git repository, you can follow these steps: 1. Fetch the remote branches First, ensure that your local repository is aware of the remote branches by using git fetch . This updates your local references to the remote branches. git fetch origin 2. Check out the remote branch Once the remote branches are fetched, you can check out the desired branch using git checkout -b and specifying the remote branch. Command: git checkout -b < local -branch- name > origin/<remote-branch- name > Explanation: <local-branch-name> : The name you want to give to your local branch. origin/<remote-branch-name> : Refers to the branch on the remote called origin (which is the default name for the main remote repository) and the branch you want to check out. Example: If the remote branch is called feature-branch and you want to create a local branch with the same name, you would run: git checkout -b feature -branch origin / feature -...
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how to describe kafka topics, 카프카 토픽 정보 확인하기

To describe Kafka topics, you can use the kafka-topics.sh script, which is included in the Kafka distribution, or Kafka Admin APIs to programmatically fetch topic information. Here are the ways to describe Kafka topics: 1. Using kafka-topics.sh Script The kafka-topics.sh command-line tool allows you to describe topics on the Kafka cluster. You can use the --describe flag to get details like the number of partitions, replicas, leader, and ISR (in-sync replicas). Command Syntax: bin/kafka - topics . sh - - describe - - topic < topic - name > - - bootstrap - server < broker - address > Example: bin/kafka - topics . sh - - describe - - topic my - topic - - bootstrap - server localhost:9092 Output Example: Topic: my-topic PartitionCount: 3 ReplicationFactor: 2 Configs: segment.bytes= 1073741824 Topic: my-topic Partition: 0 Leader: 1 Replicas: 1 , 2 Isr: 1 , 2 Topic: my-topic Partition: 1 Leader: 2 Replicas: 2 , 1 Is...
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Scan an HBase table with a prefix filter

To scan an HBase table with a prefix filter , you can either use the HBase shell , Java API , or Python via HappyBase . The prefix filter helps to retrieve only the rows whose row keys start with a specific prefix . Below are different ways to perform this operation. 1. Using HBase Shell In the HBase shell , you can use the scan command along with a filter expression to scan rows based on a prefix. Example: hbase (main) : 001 : 0 > scan 'table_name' , {FILTER => "PrefixFilter('prefix_value')" } Explanation: Replace 'table_name' with the name of your HBase table. Replace 'prefix_value' with the prefix you want to search for in the row keys. This filter ensures that only rows whose row keys start with the given prefix are retrieved. 2. Using Java API (HBase Client) If you're working in Java, you can use the PrefixFilter class from the HBase API to scan the table. Example: import org.apache.hadoop.hbase.client.*;...
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[Ubuntu] Apache2.4.x 설치

Apache2.4.x 버전부터는 APR 과 APR-util을 별로도 설치하여야 한다. 하위버전에서는 설치파일에 포함되어 있었으나 버전 업이 되면서 삭제되어 configure를 실행하면 아래와 같은 에러메시지를 발생하면서 종료된다. Configuring Apache Portable Runtime library ... Checking for APR... no Confgirue: error: APR not found. Please read the documentation http://apr.apache.org/   에서 다운받아 설치함 *APR(Apache Portable Runtime) 설치 $ wget http://mirror.sdunix.com/apache//apr/apr-1.4.6.tar.gz $ tar xvf apr-1.4.6.tar.gz ~/apr-1.4.6$ ./configure ~/apr-1.4.6$ ./make ~/apr-1.4.6$ ./sudo make install *ARP-Util 설치 $ wget http://apache.tt.co.kr//apr/apr-util-1.4.1.tar.gz $ tar xvf apr-util-1.4.1.tar.gz ~/apr-util-1.4.1$ ./configure --with-apr=/usr/local/apr ~/apr-util-1.4.1$ make ~/apr-util-1.4.1$ sudo make install Apache 재설치시 Error 발생. configure: error: pcre-config for libpcre not found.PCRE is required and available from http://pcre.org/ *PCRE(Perl Compatible Regular Expressions) 설치 $ ...
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운영체제를 개발 방법

운영체제(OS)를 개발하는 것은 매우 복잡하고 기술적으로 도전적인 작업입니다. 이는 컴퓨터 하드웨어와 소프트웨어 간의 상호작용을 관리하는 핵심 소프트웨어이기 때문입니다. 아래는 새로운 운영체제를 개발하는 데 필요한 주요 단계를 정리한 내용입니다. 1. 목적과 요구사항 정의 운영체제의 목적 : 개인용, 서버용, 임베디드 시스템 등 어떤 용도로 사용할지 결정하세요. 핵심 기능 정의 : 파일 시스템, 프로세스 관리, 메모리 관리, 네트워크 지원 등 필수 기능을 정리합니다. 목표 플랫폼 : x86, ARM, RISC-V 등 어떤 하드웨어 아키텍처를 지원할지 결정합니다. 2. 운영체제 설계 커널 타입 선택 : 모놀리식 커널 : 성능은 좋지만 복잡성이 높음. 마이크로커널 : 모듈화가 잘 되어 유지보수가 쉬움. 하이브리드 커널 : 위 두 가지의 장점을 결합. 사용자 인터페이스(UI) : CLI(Command Line Interface)와 GUI 중 어떤 인터페이스를 제공할지 결정. 멀티태스킹 방식 : 선점형(Premptive) 또는 비선점형(Non-preemptive) 멀티태스킹 구현 여부. 3. 개발 환경 설정 개발 언어 선택 : 운영체제 개발에는 일반적으로 C와 C++가 사용됩니다. 부트로더는 종종 어셈블리어로 작성됩니다. 툴체인 준비 : 컴파일러(GCC, Clang 등) 디버거(QEMU, GDB 등) 에뮬레이터(QEMU) 또는 실제 하드웨어. 버전 관리 시스템 : Git 등으로 소스 코드를 관리. 4. 부트로더 개발 부트로더는 컴퓨터가 켜질 때 하드웨어를 초기화하고 운영체제를 메모리에 로드합니다. 대표적인 부트로더 예: GRUB, LILO. 자신만의 부트로더를 제작하거나 기존 부트로더를 커스터마이즈할 수 있습니다. 5. 커널 개발 프로세스 관리 : 프로세스 생성, 스케줄링, 종료 구현. 메모리 관리 : 물리 메모리와 가상 메모리 관리. 페이징 또는 세그멘테이션 지원. 입출력 관...
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