L'installation du JDK (Java Development Kit), tutoriel java

L'installation du JDK (Java Development Kit), tutoriel java:

1.4. L'installation du JDK..........

1.4.1. L'installation de la version 1.3 DU JDK de Sun sous Windows 9x..........
1.4.2. L'installation de la documentation sous Windows..........
1.4.3. La configuration des variables système sous Windows..........
1.4.4. Les éléments du JDK sous Windows.........

19:59 by Robert dawne · 0

Tutoriel Serveur Proxy : Squid

Tutoriel Serveur Proxy : Squid:

Le serveur mandataire :

Dans un réseau local, on peut avoir envie  de  mettre  une  machine  qui  fasse l’intermédiaire  entre  notre  réseau  et Internet.  Le  serveur  proxy  (ou  serveur mandataire)  permet  de  d’envoyer  les requêtes et de recevoir les réponses à la place de ses clients. Ces requêtes peuvent être  des  requêtes  de  divers  protocoles, les plus utilisées étant le HTTP, HTTPS  et FTP, SSL.
● Un client envoie sa requête
● Le proxy la récupère et la renvoie
● Le serveur répond au proxy
● Le proxy renvoie la réponse au client.

15:35 by Robert dawne · 0

Le routage dynamique avec protocole OSPF (Open Shortest Path First)

Le routage dynamique avec protocole OSPF (Open Shortest Path First):

OSPF est un protocole de routage dynamique moderne, robuste et conçu pour les grands réseaux. On constate qu’il est nettement plus complexe que RIP. Pas forcément dans sa configuration mais dans son fonctionnement interne. Un inconvénient de ce protocole est qu’il peut être gourmand en puissance de calcul et en mémoire lorsque le réseau comporte beaucoup de routes ou qu’il y a de fréquentes modifications de topologie.

OSPF est un protocole IGP (Interior Gateway Protocol), c’est-à-dire qu’il agit au sein d’un système autonome. Un AS (Autonomous System) est un ensemble de réseaux gérés par un administrateur commun. Chaque système autonome possède un numéro identifiant sur 16 bits délivré par l’IANA (Internet Assigned Numbers Authority) ou ses délégations. Classiquement, les multinationales, les opérateurs de télécom ou les fournisseurs d’accès à Internet détiennent un système autonome. Pour assurer le routage entre les systèmes autonomes, un protocole de type EGP (Exterior Gateway Protocol) doit être mis en oeuvre. Dans le cas d’Internet, c’est généralement BGP (Border Gateway Protocol) qui assume cette mission. BGP, protocole supporté par Zebra, constitue un vaste terrain d’investigation.

15:39 by Robert dawne · 0

Tutoriel Installer / Désinstaller Lilo : Linux Loader

Tutoriel Installer / Désinstaller Lilo : Linux Loader:

Présentation de Lilo

• En particulier : Lilo est un chargeur de Linux, LInux LOader
• En général : Lilo est un chargeur de systèmes d’exploitation

Lilo permet de charger sur une machine:

• plusieurs systèmes d’exploitation différents (multi boot)
• plusieurs noyaux différents de Linux (ex: pour des tests)

15:09 by Robert dawne · 0

Tutoriel Pour Gérer le chargement du système Linux Kernel et Noyau

Tutoriel Pour Gérer le chargement du système Linux Kernel et Noyau:

Kernel ou Noyau Linux

Mise en oeuvre des mécanismes de boot et d’optimisation du noyau.

Le but de ce TP est de savoir gérer le chargement du système, de la phase de boot à celle du chargement du noyau et de ses modules, init et les niveaux d’exécution seront abordés dans un autre TP.

---

42.1. Objectifs

• Utiliser Lilo
• Utiliser Grub
• Dé/Chargement de modules
• Librairies
• Installation d’un noyau standard
• Installation d’un noyau à partir des sources

15:07 by Robert dawne · 0

Tutoriel Comment Synchroniser ses machines avec NTP

Tutoriel Comment Synchroniser ses machines avec NTP:

54.Synchroniser ses machines avec NTP

54.1. Introduction à ntpdate et ntpd sous linux

NTP (Network Time Protocol) permet de synchroniser sa machine avec des serveurs via le reseau et de garder sa machine à l’heure. Nous allons voir deux methodes pour se synchroniser: ntpdate et ntpd. Ces deux outils peuvent s’utiliser de manière complementaire ou bien de manière indépendante.

15:04 by Robert dawne · 0

Tutoriel sur les serveurs : Eléments de cours sur protocole ARP

Tutoriel sur les serveurs : Eléments de cours sur protocole ARP:

3. Eléments de cours sur protocole ARP

3.1. Le protocole ARP

L’adresse Ethernet est une adresse unique sur 48 bits (6 octets) associée à la carte Ethernet. Lorsqu’un noeud N1 du réseau TCP/IP X1.X1.X1.X1 veut émettre un paquet TCP/IP (dans une trame Ethernet) vers une machine N2 d’adresse IP (X2.X2.X2.X2), il faut qu’il connaisse l’adresse Ethernet (E2.E2.E2.E2.E2.E2). Pour réaliser l’association @ip / @ Ethernet l’émetteur N1 utilise le protocole ARP dont le principe est le suivant :

16:16 by Robert dawne · 0

Stockage des données dans une bases de données - les Index et clusters

Stockage des données dans une bases de données - les Index et clusters:

Stockage des données

Dans les bases de données, un index est une structure de données utilisée et entretenue par le système de gestion de base de données pour retrouver rapidement les données.

La taille des données stockées dans une bases de données va de l’ordre de plusieurs centaines de Mega-octets pour des bases moyennes à des dizaines ou des centaines de Giga-octets pour des bases importantes. La plus grosse base connue à ce jour atteint le Téra-octet.

06:36 by Robert dawne · 0

Exercices réseau informatique corrigé: Technique VLSM - CCNA3:

Exercices réseau informatique corrigé: Technique VLSM – CCNA3

Exercices 1

Créer un système d’adressage à l’aide de la technique VLSM.

Scénario

L’adresse CIDR 192.168.24.0 /22 est attribuée et doit prendre en charge le réseau indiqué dans le schéma.

Exercice 2

Créer un système d’adressage à l’aide de la technique VLSM.

Scénario

L’adresse CIDR 192.168.30.0 /23 est attribuée et doit prendre en charge le réseau indiqué dans le schéma.

15:02 by Robert dawne · 0

Exercices : Adresse IP, routage et sous-réseau

Exercices : Adresse IP, routage et sous-réseau:

 Exercice 1. (Rappel sur l’adressage IP)
Exercice 2. (Routage IP sans subnetting)
Exercice 3. (Route par défaut et route vers une station, toujours sans subnetting)
Exercice 4. (Routage et subnetting)
Exercice 5. (Masque de sous-réseaux et remise directe)
Exercice 6. (Extensions d’un réseau avec du subnetting)
Exercice 8. (Plan d’adressage)
Exercice 9. (Plan d’adressage)
Exercice 10. (Fragmentation)
Exercice 11. (Fragmentation)

17:57 by Robert dawne · 0

Cours informatique : Support de Formation BIOS

Cours informatique : Support de Formation BIOS:

Qu’est le BIOS ?

Le Basic Input Output System est un programme stocké sur une mémoire flash de la carte mère.

Le BIOS est l’interface entre le matériel et l’OS. Ses fonctions principales sont de gérer les réglages de la carte mère et des paramètres des cartes d’extension : date, heure, disques durs, synchronisation du matériel, modes de fonctionnement des périphériques, vitesse du microprocesseur.

15:40 by Robert dawne · 0

Cours réseaux informatique : différentes techniques et Méthodes d'adressage

Cours réseaux informatique : différentes techniques et Méthodes d'adressage:

Adressage dans un réseau d’entreprise : L’adressage hiérarchique VLS M, CIDR.

L’implémentation de commutateurs permet de réduire le nombre de collisions qui ont lieu au sein d’un réseau local. Toutefois, l’utilisation d’un réseau entièrement commuté aboutit souvent à la création d’un domaine de diffusion unique. Dans le cas d’un domaine de diffusion unique, ou un réseau non hiérarchique, tous les périphériques sont dans le même réseau et reçoivent chaque diffusion. Dans le cas des petits réseaux, un domaine de diffusion unique est acceptable.

16:42 by Robert dawne · 2

État Microsoft Access | Cours informatique gratuit

État Microsoft Access | Cours informatique gratuit: Un état Microsoft Access est une représentation des enregistrements de la base de données qui est mise sur papier. Il est possible de ressortir une synthèse à partir de ces données qui seraient plus difficiles d’avoir autrement. En plus, il est plus facile de trier et de regrouper l’information sur des champs pertinents de notre base de données Access.

13:47 by Robert dawne · 0

Base de données relationnelle sous Microsoft Access

Base de données relationnelle sous Microsoft Access: "En informatique, une base de données relationnelle est un stock d’informations décomposées et organisées dans des matrices appelées relations ou tables conformément au modèle de données relationnel. Le contenu de la base de données peut ainsi être synthétisé par des opérations d’algèbre relationnelle telles que l’intersection, la jointure et le produit cartésien.

13:44 by Robert dawne · 0

Création des relations sous Microsoft Access

Création des relations sous Microsoft Access:

• Après avoir confirmé l’exactitude du modèle de l’application avec le client, on crée les tables appropriées

• Ne pas oublier que les tables qui seront reliées doivent avoir un champ en commun: il portera un nom différent mais il doit être de même type et de même taille dans les deux tables

• Pour créer les relations en Microsoft Access on clique sur le bouton Relations de la barre d’outils:

13:39 by Robert dawne · 0

Requêtes de Microsoft Access | Cours informatique gratuit

Requêtes de Microsoft Access | Cours informatique gratuit:

Dans le chapitre précédant de ce Cours Access, nous avons vu  la création des tables qui permettent de rentrer les données (enregistrements) dans des champs délimités. Ces tables ne permettent pas de faire un tri ou un Un filtre avancé qui vous permet de créer des champs pour générer des rapports à partir d’un ou de deux champs existants sur les enregistrements de la base de donnée de Microsoft Access. Cette fonction est dévolue en grande partie aux requêtes. Une requête est liée à une (ou plusieurs) tables, elle reprend ses données et les organise.

14:57 by Robert dawne · 0

How Do You Cultivate Innovation ?

Being innovative means solving a problem in a unique and creative way. Companies like Google, Apple, GE and Facebook have made billions because innovation is a principal value in everything they do. Given the positive associations with it, every organization likes to think it fosters innovation, but unfortunately, the truth is often much different. This week's Culture Beat explores the qualities of truly innovative cultures. How does yours stack up?
Promoting Pride in the Individual and the Organization
According to research recently published in the Journal of Business Venturing, which looked at two decades of data on 62 countries, both individualistic and nationalistic cultures support innovation. While it’s not a major surprise that individualism is strongly associated with innovation, a more intriguing finding is that cultures that value the success of the group and have high degrees of patriotism also encourage innovation in their people. Countries like Japan and Sweden, for instance, are traditionally more collectivist but are also extremely innovative.
Employing Transformational Leadership
Transformational leadership is a management style that seeks to positively impact the attitudes and behaviors of followers. Frequently described as high-energy and high on passion, transformational leaders are focused more on success of the people responsible for the outcome than the success of the outcome itself. Such managers promote intellectual curiosity, open communication, performance rewards and professional development. They are able to articulate a clear vision for progress and, by appealing to the moral high ground, serve as an inspirational role model for employees. Michael Dell of Dell, Jeff Bezos of Amazon, Lou Gerstner of IBM and Martin Luther King Jr. are oft-cited examples of transformational leaders.
Giving People Permission to Fail
True innovators know that hitting upon a successful idea is a process of trial and error, and more often than not, you have to experiment with several approaches before finding one that works. Cultures infused with innovation are not risk-averse and don’t hold people back by always insisting on a revenue-winning outcome. By giving employees the freedom to fail, organizations also open themselves up to spectacular wins. Sounds a bit like transformational leadership, doesn’t it? And one need only to look at Microsoft to see it in action.

Don’t Restrict the Focus to R&D
Throwing some budget at research and development departments, or launching a siloed “innovation committee” will not definitively move your culture in the right direction.  Instead, employees in all areas of the business must be encouraged to weave innovative thinking into everyday tasks and projects, and should be rewarded for doing so.
Innovative Cultures Don’t Need Gatekeepers
Fast Company Co.Design bloggers Jens Martin Skibsted and Rasmus Bech Hansen claim that there is a new type of professional in American businesses specifically tasked with innovation. “Innovation custodians” are middle managers assigned to oversee innovators and their processes. “Innovation word-slingers” are external consultants who lead in-house innovation workshops. The problem with innovation professionals, say Skibsted and Hansen, is that they rarely have the maverick outlook that it takes to innovate in a substantive way. Also, innovation should be an attitude that organically runs through the heart of an organization and cannot be easily implemented by a manager with a to-do list.
Do you think your culture breeds innovation?  What advantages and disadvantages do small businesses have in this regard?
Alexandra Levit is a former nationally syndicated business and workplace columnist for The Wall Street Journal and the author of Blind Spots: The 10 Business Myths You Can’t Afford to Believe on Your New Path to Success. Money Magazine’s Online Career Expert of the Year, she regularly speaks at organizations and conferences on issues facing modern employees.

12:49 by Robert dawne · 1

Finding Your Small-Business Calling on Vacation

Most tourists enjoy shopping, but two former corporate executives took it a step further by importing the products they discovered on vacation.
Debby Ruth, an executive on the fast track at a major cable television company, fell in love with Hester van Eeghen’s quirky and colorful handmade leather bags on a shopping trip to Amsterdam in 2004.
“I was absolutely mesmerized and spent half a day in Hester’s boutique,” recalled Ruth, who is now the exclusive U.S. importer of van Eeghen’s handbags, gloves and wallets via Hester van Eeghen U.S.
Ruth admits she never planned to start a small business. But when she was laid off in 2008, she decided to invest her severance package in her own venture: selling van Eeghen’s goods in the U.S.
Amsterdam or Bust
Contacting van Eeghen to discuss the potential business venture was the first challenge. “It took eight months to reach her,” Ruth says. “Hester is one of the busiest women you’ve ever met. I finally hopped on a plane and flew to Amsterdam—without even having an appointment.”
When they finally met over dinner, they explored ways to sell the Italian-made purses, gloves, wallets and briefcases to American fashionistas. Van Eeghen’s hand-sewn bags are pricey, retailing for around $900 for a purse and $300 for leather gloves.
But Ruth’s persistence paid off and so far, the relationship has been positive, according to van Eeghen.
"Working with Debby on the HVE US online boutique was a natural way to have a greater presence in the United States,” said Hester Van Eeghen via e-mail. “We have found the American customers in our Amsterdam shop to be very enthusiastic about my designs. I thought creating the online boutique first would be an ideal way to reach as many people as possible but in a way that was organic."
A Walking Billboard
Soon after van Eeghen made Debby Ruth her exclusive U.S. distributor, Ruth tapped her husband, Tim Lenz, to help her design the sophisticated, minimalist website. Lenz also shot all the photos of van Eeghen’s wares.
Launched in 2010, sales have grown steadily. Ruth said she and van Eeghen split the revenue on the bags sold via the U.S. website. She declined to reveal the financial details of the arrangement or share annual revenues for the privately held U.S. company.
“Our goal is to get big enough to open physical locations,” Ruth says. Meanwhile, she is a walking billboard for her product. “Whenever I’m carrying one of Hester’s bags, people stop me to ask where to buy it.”
Boutique Bubbly
While Debby Ruth found a new career importing handbags, Ruth Frantz, a beverage industry executive, also had a life-changing experience while vacationing abroad. She was visiting several small, mostly family-owned vineyards in France when she was inspired to import the boutique champagne into the U.S. Frantz felt confident she could pull it off, having worked on the global marketing of Ketel One Vodka for a major liquor distributor.
“There are about 4,000 champagne producers in France, yet most Americans only know Moet and Veuve Clicquot,” Frantz says.
Her mission is educating Americans to enjoy the sparkling wine more freely. It’s a challenge, because most Americans drink champagne only for special occasions, Frantz says. Europeans, however, drink champagne to kick off an evening of eating and drinking.
She created a character called Henri and founded Connecticut-based Henri's Reserve about two years ago. For sale is a gift package called the “Guaranteed Seduction Kit” for $300, which includes truffles and candles. One top seller is the $160 "tasting kit" featuring three bottles of champagne and pre-printed cards for making notes about the different wines.
Scaling Up
Frantz depends on food writers, wine bloggers, Facebook and other social media platforms to spread the word about Henri’s Reserve. “We started very small and now it’s all about scaling up,” she says.
Because importing liquor to the U.S. is highly regulated and complicated, Frantz relies on Robert Houde, a Chicago-based wine expert, to manage the logistics. “I source the wines and get them into the country for Ruth,” Houde says. “Our customers really like that these are real wines from real vineyards, versus mass blended wines from big companies.”
Small restaurants looking to set themselves apart from the competition by offering a selection of unique, boutique champagne are a growing percentage of Henri’s Reserve's sales. The privately held company does not release revenues, but Frantz says that although she started the business during the recent recession, sales are growing.
Have you ever drawn business inspiration from a vacation?

12:43 by Robert dawne · 1

5 Branding Tips for Your Launch

Branding is an essential part towards building a sustainable business. As an expert, I’ve seen a lot of companies succeed or fail based on their brand identity. People are willing to spend more money on companies that they’ve heard of before and those that have a strong reputation. If you fail to establish a strong brand identity, your competition will beat you and you will be forced to compete solely on price–which will stunt growth. Here are five ways to ensure that your brand is successful when you launch your company:
1. Logo and Website Design
We live in a culture that wants things to be aesthetically appealing. Having a firm understanding of what your business says in a visual sense can help you create a design and feel for your branding collateral.
The visual aspect of your logo and website should speak in both literal and figurative terms, about the character of your business. If you are a wholesale wine distributor, it make sense to have a bottle or a glass of wine in your logo, or perhaps you want something a little subtler. A bundle of grapes or a wine barrel could work just fine. Decide what characteristics you want your business to stand for about the industry you’re in, and try to visualize it. This will enable you to describe to developers what look you're going for. Your logo and website will define your business both online and offline, so make it something you’re proud of.
2.  Social Network Business Profiles
These sites are an important part of your online influence, and a great avenue to reach your customers. Once you’ve decided that a business profile is for you, I would recommend looking into other companies you look up to, and note what they’re doing well with their profiles. You want to generate content that your fans will find interesting, and want to share. Some of this information can be deals, or information on products or services you provide, but you might want to also post articles or videos you find helpful, useful, or entertaining.
3. SEO
As a small business owner, the hardest obstacle you’ll have to overcome is being “seen." The Internet is littered with small business websites all vying for the same small corners of the web. It’s imperative you focus on driving more traffic to your site, and drive up your search engine optimization. Social networks can help a lot, as well as having a blog as part of your site. Identify ways you can reach your customers (advertising, partnerships, etc.) and take the necessary steps to get your name out there. The more unique visitors you can drive to your site, the better your Google rank will become, which in turn makes you more visible online.
4. Publicity
PR is another great way to make yourself visible both online and offline. If you’re involved in any sort of charitable work, alert local media so they might want to cover it. Position yourself online as an expert in your field, and make yourself available for comments and opinions. Target smaller publications and blogs at first to build up your persona, and create working relationships with the media. PR can get very expensive very quickly if you pay for it, so as a small business it makes the most financial sense to take care of it in-house. I offered to write articles for various publications on and offline to build up my reputation, which has to led to many free PR opportunities for my company.
5. Testimonials
Once your business is up and running, make sure you connect with your customers so you understand what is working and what isn’t working. Don’t be afraid to tweak your product or service, and be receptive to feedback. It’s important to understand that no matter how much experience you have in business, you never cease learning how to do business better. When your clients are happy and vocal about your product or service, ask them for a testimonial. You can share these on your site, and it will prove your worth to other potential customers as well as instill trust in possible future clients.
Dan Schawbel is the managing partner of Millennial Branding, a Gen-Y research and management-consulting firm. Subscribe to his updates at Facebook.com/DanSchawbel.

12:01 by Robert dawne · 0

Study Finds Interns Not Getting Hired.

Newly minted college graduates are caught in a bind. More than ever, first-time job seekers need to have an internship or two on their resumes to be competitive applicants. But internships are rarely a shortcut to full-time employment; a survey released last month showed half of employers haven’t hired any interns in six months.
The findings help explain why half of all recent college graduates are jobless or underemployed, says Dan Schawbel, founder of Millennial Branding, a Generation Y research and consulting firm in Boston, which commissioned the study.
No Guarantees
"Employers have high expectations of interns, yet they don’t hire interns and they don’t hire into full-time jobs,’’ Schawbel says. “ A lot of people think if they get an internship it will magically turn into a job, but those expectations are gone.’’
Experience Inc., a career services provider for colleges, conducted the study by examining the hiring practices and employment needs of 225 companies in its data pool of 100,000 U.S. companies.
The survey found that employers believe students need to pay their dues as interns; a majority of survey respondents said job-seeking students should perform more than one internship and 87 percent of respondents said an internship should last at least three months. But spending a semester as an underpaid underling is no guarantee to employment. Of the companies surveyed, only 16 percent said they hired at least half of their interns. More than a quarter of companies surveyed hired none of their interns as full-time workers.
“Students should strive to have as many internships as possible before graduation and not rely on a single employer for a job offer,’’ says Schawbel, who says he landed seven internships in college.
Not All Doom and Gloom
But there is good news for the 1.7 million college students who are earning diplomas this spring. Nearly 90 percent of employers surveyed say they are going to hire more recent graduates this year.
The study found that a third of companies are recruiting engineering and computer information systems majors and nearly a third have sought liberal arts majors. Just 18 percent are recruiting finance and accounting majors combined.
What Employers Really Want
Taking junior year abroad shouldn't make or break a resume; fewer than half of employers said that a graduate’s global perspective was vital. Just a little more than a quarter of employers said they prized a graduate having years of experience.
Nearly all employers view communication skills as being important or very important when hiring entry-level workers, the study found. Employers also cited positive attitudes and teamwork skills as nearly as important.
Companies prize soft skills—such as clear writing and sharing information—over hard skills and view the soft skills as ones that are hardest to find in new recruits, Schawbel says.
Check the Attitude
But having the right skills won’t suffice if a student flubs an interview. More than 40 percent of employers in the study reported being turned off by how unprepared students were in interviews and a quarter found the interviewees showed a bad attitude.
Schawbel says that while most employers aren’t on the Web hunting for students, students must look there, and everywhere else.
"You got to use everything at your disposal: networking, career services, joining philanthropy groups, using the social networks, getting active on LinkedIn groups,’’ he says. “ My whole mantra is, you can’t rely on anything.’’
Has your business taken on interns? How many have you hired for permanent positions?

11:56 by Robert dawne · 1