Open System Interconection Model is used for communication between two computers. It has seven layers. I will describe the layers one by one.
1. Physical Layer: It is the lower layer of OSI. In this we select the voltage level used for representing 0 & 1.
2. Data Link Layer: In this layer, data is divided into frames and sent to Physical layer.
3. Network Layer: Here data is divided into packets.logical address is also given in this layer.
4. Transport Layer: This layer provides error free channel.
5. Session Layer: This layer controls the login sessions.
6. Presentation Layer: In this layer data is encryted and compressed.
7. Application Layer: All the various protocols are included in this layer like http,ftp,SMTP etc. This layer directly interacts with the user.
There are many tasks in life which are still nearly impossible to perform with computer.
Often these tasks are extremely simple tasks for humans to perform. Let’s take the task of summarizing. A computer is completely unprepared for dealing with matters of language, whereas you or I may be able to read a paragraph and very quickly summarize it. Crowdsourcing is a method born out of this dilemma. How does an individual or business with tasks like these find the workers needed to complete these tasks quickly? A website owned by Amazon, currently in beta, is one such solution. Workers pick up very small amounts of money for completing these simple tasks. Employers get these tasks completed very quickly for cheap, because they are outsourced to a large crowd of individuals. Often times, employers get thousands of human intelligence tasks completed in an hour. In a nutshell: Crowdsourcing is an innovative new way to use technology to aid humans in completing tasks that only humans can complete. It gets work from employers to the maximum number of humans as fast as possible.
Windows XP users familiar with the picture resizer powertool which adds a basic batch picture re-scaling tool to explorer were upset to realize that the XP power tools don’t work with Vista.
The basic function offered by this tool was pretty handy. Enter the VSO Image Resizer, a completely free software tool that can re-scale a folder of pictures, save it as a JPEG, GIF, TIFF or BMP at the quality that you specity. The tool launches from the right-click drop down menu in explorer and offers simple and basic functions in an intuitive interface. For non-commercial use there is no cost for the software. It even works on Windows XP.
StrokeIt – A Mouse gesture software I recently stumbled upon. It is called the Mouse Gestures. For those of you who aren’t familiar with the term, let me explain.
Mouse gesture is an ingenious way of tracking the way you move your mouse and convert it to a specific command for your computer. Now, some of the impatient among you might ask but we move our mouse all the time in all the ways; so, how the tracking is done exactly. The answer is that in order to make Mouse Gestures the user has to press one of the buttons on the mouse like the left-click, the middle-click etc. When the user makes gestures through the mouse while keeping one of the mouse buttons pressed the software tracks the gesture and triggers the specific command associated with that gesture. Coming to the software StrokeIt, the command to be associated with a gesture can be anything from opening an application to performing a specific action inside an already running application. For example, while watching a movie on Windows Media Player you can draw a ‘P’ symbol from your mouse and the movie will Pause, or you can draw a ‘C’ symbol and the player would Close altogether. What’s even better is that, with StrokeIt, the users can define their own custom gestures. That is, apart from the pre-defined gestures the users can satiate their creative desires by creating their very own artistic gestures and associate a command with it. For example, I have a specific symbol each for opening my web browser, opening a particular bookmark, and even for downloading its contents to my hard drive. Give it a shot, its worth it.
Do you find yourself tasked with creating training, software demos, or client how-tos for your small or medium-sized company?
Adobe Captivate‘s new version, Captivate 3, saves time in creating these materials without overloading you with a high learning curve for the software itself. Captivate outputs your screen recordings in Flash format so that you can post the results to the web or distribute on CD-ROM. Captivate’s intuitive interface makes it easy to capture and annotate screen events via text and audio, and produce a professional-looking result in hours. Captivate’s first release, based on the earlier RoboDemo, was already easy to use for training. For quizzing, new question types and question pooling make creating tests with Captivate more flexible than before. You can more easily test the effectiveness of your training and identify areas for follow-up. The powerful annotation features allow you complete flexibility of text presentation in the video, but if you need to create documentation as well as demos and videos, Captivate also allows you to print to Word or PDF. Addition of music tracks or voiceovers is incredibly simple, as are the addition of static or interactive images.
I am not a Perl fan, but as a network administrator it has always been a vexing task to find backup software that can handle everything that can be thrown at it.
Especially as technology advances and the amount of space we use in our networks have exponentially increased in size. Another caveat is having mixed technology, it throws a spanner in the works for any backup technology. As far as backup hardware, it has fallen by the wayside, a tape streamer can no longer handle the huge amounts of data on a network. BackupPC, when run on a dedicated Centos machine with a couple of raided SATA drives does absolutely wonderful with backing up a network. It handles large files brilliantly, has an amazing flexibility in its configuration, and has a pooling, and compression future which is incredible with space savings. We have about 1.5TB of data that is backed up on our network, and takes less than 500MB actual space after the pooling, and compression. The biggest headache is to install it, and to configure it correctly, (a reasonable Linux understanding is a bonus) once that is done, it never has to be worried about again, except when you need to restore something, or add a new device to backup. Though it is always a good idea to do regular checks to see if the backups went through. The benefits of a working system outweigh any installation difficulties.