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À quoi sert une carte ?

Il n’existe pas de planisphère exact. Il n’existe que des planisphères utiles, chacun pour une question précise. Petit tour des cartes que nous utilisons déjà tous les jours sans le savoir. Ouvrez trois cartes du monde. Sur la première, le Burkina Faso est une petite tache au sud d’un Sahara immense, sous une Europe imposante et un Groenland de la taille d’un continent. Sur la deuxième, l’Afrique s’est dilatée, le Groenland a fondu, mais la Norvège paraît écrasée comme sous une presse. Sur la troisième, la Terre est ronde, on voit l’Afrique entière et le Burkina au centre ; l’Australie, elle, a purement et simplement disparu. Laquelle est la vraie ? La question paraît légitime. Elle est pourtant mal posée, et c’est tout l’objet de cet article. Une carte n’est pas une photographie du monde ; c’est la réponse à une question. Avant de demander si une carte est juste, il faut demander à quoi elle doit servir. Le géomètre, le pilote, le climatologue, l’imam et l’élève ne posent pas la...
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Quelques cycles dans la nature

  Cycles de courte durée (Heures et Jours) Marées (12h 25min) : Utilité/Phénomène : Navigation maritime, écosystèmes côtiers (estuans), production d'énergie marémotrice. Jour solaire (24h) : Utilité/Phénomène : Alternance lumière/obscurité. Base de l'organisation sociale et du travail. Jour sidéral (23h 56min) : Utilité/Phénomène : Astronomie de précision. C'est le repère pour pointer un télescope vers la même étoile chaque nuit. Rythme circadien (~24,2h) : Utilité/Phénomène : Biologie humaine (sommeil, hormones, température corporelle). Explique le "jet-lag". Cycles de moyenne durée (Mois et Années) Mois lunaire (29,53 jours) : Utilité/Phénomène : Calendriers religieux (Ramadan, Pâques), cycles de reproduction de certaines espèces marines, coefficient des marées. Année tropique (365,24 jours) : Utilité/Phénomène : Cycle des saisons. Crucial pour l'agriculture (semis/récoltes) et la survie de la faune (migrations). Cycle de Jupiter (11,86 ans) : Utilité/...
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Testing crossplane on Digital ocean

  Crossplane brings the management of external resources into kubernetes through kubernetes APIs. This can in some situations be an alternative to other IaC such as terraform.  In the example below, we will create a droplet on DO by applying a kubernetes manifest using kubectl. The exemple suppose the kubernetes cluster in which crossplane will be installed is already up. ```bash kubectl create namespace crossplane-system helm repo add crossplane-stable https://charts.crossplane.io/stable helm repo update # install crossplane helm install crossplane --namespace crossplane-system crossplane-stable/crossplane # install the upjet digital ocean provider cat << EOF | kubectl apply -f - apiVersion: pkg.crossplane.io/v1 kind: Provider metadata: name: provider-upjet-digitalocean spec: package: crossplane-contrib/provider-upjet-digitalocean:v0.3.0 EOF # create the upjet digital ocean provider secret kubectl apply -f - << EOF apiVersion: v1 kind: S...
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GIT

  Git is a version control system that is used to track changes to files and manage projects. It is a powerful tool that allows developers to collaborate on projects and manage the source code of their projects. Some common Git commands include: git init: This command is used to initialize a new Git repository. It creates a new directory and sets up the necessary configuration files and directories. git clone: This command is used to create a local copy of a remote repository. It allows a developer to download a copy of the repository and all its history to their local machine. git add: This command is used to add new or modified files to the staging area. The staging area is a temporary holding area where changes are stored before they are committed to the repository. git commit: This command is used to save changes to the repository. It creates a new snapshot of the project and adds it to the repository's history. git push: This command is used to send changes from the local repo...
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USSD

 USSD (Unstructured Supplementary Service Data) is a protocol used for transmitting data over a cellular network. It is commonly used for interactive services, such as mobile banking and interactive voice response (IVR) systems. USSD is based on a session-based model, in which a user initiates a session by sending a request to the USSD server. The server responds with a message, and the user can then send additional requests and receive responses within the context of the session. When the user is finished, they can terminate the session. USSD is often used for services that require real-time interaction, such as mobile banking. To use a USSD-based service, a user typically needs to dial a specific USSD code on their mobile phone, which initiates a session with the USSD server. The user can then enter commands and receive responses from the server. USSD is a fast and efficient way to transmit data over a cellular network, and it is widely used for interactive services. It is partic...
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SMPP

 SMPP (Short Message Peer-to-Peer) is a protocol used for exchanging short message data between entities, such as SMS (Short Message Service) service centers and external applications. It is commonly used by businesses and organizations to send and receive SMS messages and other short messages, such as alerts and notifications. SMPP is based on a client-server model, in which a client (such as an SMS service center or an external application) sends and receives messages through an SMPP server. The client and server communicate with each other using a series of commands and responses that follow a specific format. When a client wants to send an SMS message using SMPP, the following process occurs: The client connects to the SMPP server using a network connection, such as TCP/IP. The client sends a message to the server indicating the sender and recipient of the SMS message, as well as the content of the message. The server checks that the recipient's phone number is valid and, if it...
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SMTP

 SMTP (Simple Mail Transfer Protocol) is a standard protocol for transmitting email over the internet. It is used by email clients, such as Microsoft Outlook or Apple Mail, and email servers to send and receive emails. SMTP is a client-server protocol, which means that an email client sends an email to an email server, which then delivers the email to the intended recipient. The email client and server communicate with each other using a series of commands and responses that follow a specific format. When an email is sent using SMTP, the following process occurs: The email client connects to the email server using a network connection, such as TCP/IP. The email client sends a message to the server indicating the sender and recipient of the email, as well as the subject and body of the email. The server checks that the recipient's email address is valid and, if it is, sends a message indicating that the email has been accepted. The server delivers the email to the recipient's em...
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