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As we started the project of our web site, we knew that the proprietary software costs would be too high for our financial resources. Our only option then was to make use of Open Source Code softwares.

However, within the Open Source Code there are lots of softwares to choose from, and it?s up to the system analyst/programmer to pick the ones that best suit the project goals.

In our case, we picked Linux as our operating system. However we faced a big question: Which Linux distribution ? There are dozens of linux distributions, each one with specific advantages, sometimes with or without paid services.

We chose linux Slackware because we thought that it would suit better our needs, in terms of stability and reliability. Slackware is a conservative distribution, meaning that it only offers in its distribution package kernel versions and third party libraries, once it?s been proved to be stable and reliable. As a result, Slackware is one the most stable Linux operating system on the market. If the user wishes the most recent Linux kernel and libraries, we recommend to look for a different distribution.

Another reason for us picking Slackware, was because of its text interface, which at the beginning may become a bit difficult, in the long run however it offers a better understanding of the Linux environment. This way most of Slackware configurations are done thru text scripts.

Once it was set the operating system, we picked Apache as our web server. Apache is one of the most popular web server in the internet. For server programming language, we chose PHP. Also, a very popular programming language. Our experience with Apache/PHP proves that this setup is very reliable, working extremely well in our production environment. For workstation programming language, we chose javascript, which besides of having a simple syntax, it offers lots of resources.

Apache web server is really a complete web server. Also, it can become very complex with many configuration setups.

For our database, we picked Postgresql. This database has been made available to the public for more than 15 years, and besides of being well debugged, it offers so many resources that it has become one of the best database options from Open Source Code softwares. Extremely reliable, Postgresql has reported cases where there have been databases in production with over 4 terabytes. Besides all of that, Postresql is not the most popular Open Source Code database. A matter of marketing ? Probably.

As for the programming language PHP, we had to use an object oriented application structure. There are many PHP application structures being offered with Open Source Code license. Object oriented application is very important, because it makes programming very easy and scalable up to the point where the system may grow without many problems. Also, it helps to keep PHP code separated from HTML, with the help of some specific libraries, such as Smarty. We make use of Smarty library and we believe that it is a very important resource, which can even make web pages faster thru the use of its cache functions.

Also a very important set of libraries worth mentioning for PHP systems, is the PEAR libraries. In PEAR web site, among the many libraries being offered, there are the database interface DB and the MAIL_QUEUE, which sends emails thru the use of database.

As we came to the end of our project, we had to use some sort of real time database replication. For that we chose the DRBD and Heartbeat libraries. The use of database replication is very important and should not be postponed. Just after 3 months our system got into production, our server hard disk became bad. Thru the use of DRBD/Heartbeat we were able to put the system back into production within seconds, without loosing any data. DRBD/Heartbeat replication is done thru the use of a lan network between the server and slave nodes.

Our project also makes use of ImageMagick (enlarge and reduce images), Iptables (firewall), Tsearch2(text search in portgresql) and Mon (linux monitoring tasks).

Also a very important library worth mentioning is the pseudo APC compiler for PHP. Speed is always a critical factor for internet sites.

Our web site is already in production and based upon our experience we can say that the Open Source Code softwares we picked, proved to be extremely reliable and stable. Open Source Code softwares can certainly be an excellent option for developing web sites.

Roberto Sedycias
IT Consultant

This article is under GNU FDL license and can be distributed without any previous authorization from the author. However the author?s name and all the URL?s (links) mentioned in the article and biography must be kept.

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This article can also be accessed in portuguese language from the News Article section of page PoloMercantil

Roberto Sedycias has a bachelor degree in Business Administration and over 20 years experience in systems analysis and computer programming. Currently working as IT consultant/chief software engineer for www.PoloMercantil.com.br

One of the most useful tools in Microsoft Excel is the capability to apply formulas to the data within your spreadsheet. This tool is also one of the least understood.

Just a little excel software training will help you to understand some of the basic functions available, allowing you to produce useful models and perform some complex calculations.

How does a formula work?
Formulas are equations that will perform calculations on the values you have entered into your spreadsheet. A formula in Excel will always begin with a equals sign, this tells Excel that the characters following it constitute a formula. Following the equals sign are the elements of a calculation separated by calculation operators. A formula may contain any or all of the following, functions, references, constants and operators. An example of a simple formula is given below;

=PI()*(C6+5)

The above example contains each of these elements. We will now consider the role of each of these to understand how the formula works.

Functions
Functions are predefined formulas that perform calculations by using specific values in a particular order or structure. A function begins with an equals sign followed by the function name, an opening bracket, the arguments for the function separated by commas and then a closing bracket. For example, the PI() function returns the value of pi i.e. 3.142.

Operators
An operator is a sign or symbol that specifies the type of calculation that you want to perform on the elements of the formula. Operators may be of four types, mathematical e.g. * (multiplication sign), comparison e.g. greater than, logical e.g. & (and) and reference e.g. : (colon).

References
A reference identifies a cell or range of cells in a worksheet and tells Excel where to look for the data you want to use in the formula. You can refer to cells within the worksheet, in other sheets in the same workbook and even to other workbooks. For example, the reference A2 would return the value in the cell A2.

Constants
A constant is a value that is not calculated and therefore does not change, for example the date 3/10/06 or the number 105. If you use constant values in a formula instead of references to cells the result will only change if you modify the formula yourself.

Formulas calculate values in a specific order. Excel calculates the formula from left to right. If you combine more than one operator in a formula, for example both a multiplication and plus operator, you may want to specify the order in which these operations is completed. This is done by adding brackets around the part of the formula which is to be calculated first.

An example formula
We can now return to our original formula and look again at the elements within it.

=PI()*(C6+5)

PI() = a function that will return the value of PI (3.142)
* = the mathematical operator for multiplication
C6 = a reference which will look up the value in cell C6
+ = the mathematical operator for addition
5 = a constant value

If the value in cell C6 is 10 then this formula will first add 10 to 5, and then multiply the resultant (15) by 3.142 to return the value 47.12.

The above provides just a very simple example to provide a basic overview of the way formulas work. There are numerous other functions and operators that can be applied together with many ways of referencing data. By undertaking some basic excel training you can quickly gain the knowledge to put all these functions to use and get Excel to do the hard work for you.

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Author is a trainer with a Microsoft Office training company, the UK industry leader in its sector. For more information on Excel training, visit www.MicrosoftTraining.net.

If you teach courses in a college or university, you run tests and exams quite often. Preparing an exam and assigning points is a complex and time-consuming process.

Running it is another complex matter; and there aren’t many things that take more time than grading the exams. And don’t forget entering those grades into the system, which can take another hour or two depending on the size of the course.

In the hi-tech era of computers, paper-based tests are quickly becoming obsolete. They are too complex to prepare and run, and consume too much time. Grading precision is highly human-dependent and the grades are often disputed by the students with the teachers or grading assistants.

Using computers for running tests is quickly becoming a standard. Computer-based tests are faster to prepare and more secure to run. The questions can be graded instantly and precisely.

Adit Testdesk is a comprehensive software suite that enables you to create, run, and grade a wide variety of fully adaptive tests on a variety of academic, technological or psychological subjects. Unlike many systems with similar features, Adit Testdesk was developed with usability in mind, making it easy for a teacher to learn and to use.

The product is optimized for busy environments and complex testing. You can give each test and every question a unique appearance with a customizable design. Adit Testdesk handles all types of questions from the paper-based tests, and introduces new ones that are only possible with the use of a computer. You can, for example, embed apicture, an audio or even a video clip into a question, or even a set of videos as possible choices for an answer. You can embed tables, fonts, colors, and any other types of OLE data objects, making your questions and answers appear just the way you need them to be.

With Adit Testdesk you are in full control of all settings of a test or exam. You control the rules on how the questions are selected, which allows you to create fully adaptive tests. You can group questions into topics, as well as create different testing profiles that describe the scoring and the order of questions, allowing you to run different exams with a single pool of questions.

Security is a very important concern for computer testing, and Adit Testdesk takes this issue very seriously. With a powerful access control system, you can grant different access rights to certain groups of users, assigning different passwords for viewing and modifying test data. The results can be protected with strong encryption to prevent tampering and unauthorized access.

You don’t need to install Adit Testdesk on every student’s computer. It is easy to create executable files for your tests. They can be run on every computer, either stand-alone or from a network server. A special server edition allows performing tests over the local network or the Internet.

And grading the exams could not be any easier. Besides the obvious multiple choice options, Adit Testdesk includes support for scripting tests, where a script determines the result of the testing. This allows using crossing scales, and provides the ability to analyze the results.

With Adit Testdesk, you can import and export test data and test results into a universal XML format, which allows you to perform comprehensive analysis in any application supporting the XML format, such as Microsoft Excel.

An evaluation version of Adit Testdesk is available as a free download. Get your copy today at: http://www.aditsoftware.com/download.php.

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Denis Sletkov is CEO of Adit Software. Adit Software was founded in 2005 as an information technology company and has since become famous for its testing software.

No one likes someone overseeing what they are doing. Specially if it is the Internet, such interference is definitely not invited. On the Internet, person usually browse with the idea that they are alone and no one is watching them, but that is exactly what does happen.

The thing is each computer connected to the World Wide Web has an IP address which is given by the Internet Service Provider. This IP address is the sole identifying factor of a computer’s Internet activity. That means, the IP address can reveal each and every communication a person using that computer has completing on the Internet, including all the websites they have browsed.

However the want of such a device is justified on security grounds, several people do consider recording and tracing computers with IP addresses is a infraction of their secret. It could also be an invitation for hackers and such antisocial elements to seek out private data about the computer user, if the computer is a personal terminal and then create complicated problems. For such reasons, it becomes necessary sometimes to hide IP address of the computer.

Though, there is no reason to worry. Technology has accorded us with a very simple, efficient and perfectly legal method to fake IP addresses. It is called as an IP masking or IP faking software system, and a very popular product in this line is developed by IP masking or IP faking software. Let us see how this system works.

When anyone logs on to the Internet, the IP address of the computer is relayed over the domain. Anyone in that domain can then get access to the IP address and come to know which computer it belongs to. Since IP addresses are unique to computers, this is very easy to do.

But a product like IP masking or IP faking software will break this direct connection of a computer with the Internet. It will connect through a fake IP relay system, which will generate a fake IP for the computer. Anyone tracking the IP address of the computer will then see this fake IP and not the original one that was provided by the Internet Service Provider. This will mask the original IP, but anyone trying to track the computer will not know that it is fake.

In fact, such hide IP address software will provide a list of countries from which the log in can be made. The generated IP address will show the computer is connected from another country altogether.

IP masking software are very user friendly and convenient to use. Many people are using them to get supremacy security and privacy in their Internet communications.

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Sean recently conducted a seminar telling people how to Hide IP Address. He has advocated the use of Hide My IP software for this purpose. You can read some of his reviews of the product on his review website:
www.hidemyipreviews.com

When it comes to entering the graphic design world, creating interesting pieces for a job or sharing artwork with family and friends, there are plenty of cool Photoshop tips and tricks to consider.

Whether you are just experimenting with the tools or already know how to layout a magazine spread, there will always be a new shortcut or trick to make life much easier. Below, you will find a few tips to add to your repertoire or share with others:

Easy Photoshop Tips and Tricks

Have you ever wanted to easily create the image of Earth and dread using the circle tool? There is an easy way to design the world in six steps, which should take less than a minute to complete. First, you should select File/New from the menu bar and create a file size that measures about 200 pixels by 200 pixels. The RGB mode should be selected for this trick. Next, choose a light blue shade for the foreground color and a darker blue for the background color.

Under the Filters tab, select Render, and then choose Clouds. The scene that will greet you should look a lot like the sky. It is the clouds filter that utilizes the foreground and background colors needed to construct this image in your file. If you desire a different look, you can press Ctrl + F on Windows or Command + F for a Mac to reapply the filter. Each time this key combination is pressed, you will receive a somewhat different outcome.

Now, return to the Filter menu and select Render, and then choose Lighting Effects. Once you enter the Light Effects menu, you are able to alter the shape of the ellipse to a circle that becomes centered on your file. Changing the Narrow setting to 39 next follows choosing the Default Spotlight setting.

Sometimes a Photoshop project calls for texture. There are thousands of backgrounds to create that range from a grainy composition to a multi-faceted mess (depending on the look you are going for). To create a paper texture in Photoshop, you should start a new file that measures 60 x 60 pixels. The color should be in RGB. Next, select the following commands in this same order: Filter, Noise, Add Noise. Once completed, choose Gaussian, which is set to 80%.

The next step to create a paper texture is to select Filter, then Stylize, followed by Emboss. The angle should be set to -50, the Height to 2 pixels, and the Amount to 70%. The background will now resemble a gray embossed selection. To change the color, choose Image, then Adjust, followed by Hue-Saturation-Brightness. Once you select the Colorize checkbox, you should set the Hue to a different setting. To gain your personal preference, you can adjust the contrast.

To create the appearance that objects are glowing without using any filters, choose an object to work with that will be duplicated as a layer. First, select the color you’d like your glow to be. After choosing the lower duplicate, click on Edit from the menu, then Stroke. When the Stroke Options appear, the pixel width should be set between 1 and 16. It is important to remember that the larger number you choose, the thicker the glow will appear.

Before exiting, you should glance under Location to make sure that the Outside option is selected. The next step involves applying a Gaussian Blur to the layer, which can be found under the Blur option in Filters. This will soften the glow applied to the layer. Some individuals even repeat the process to create a double glow, which is some cases, can really make an image stand out.

What Can You Do With Advanced Photoshop Tips and Tricks?

Advanced Photoshop users are often familiar with all tools and have mastered most of the fundamental tutorials, tips, and tricks, such as creating a cloudy background. Some people are unaware of all of the cool tricks that Photoshop has to offer, especially when you’ve upgraded your version to CS. The power to create some of the most impressive works of digital art are only a few clicks away once you get a hang of advanced Photoshop shortcuts and tricks.

Some Photoshop tricks on the advanced level can help a more tedious project seem easier. The more you learn the tips and tricks of the trade, the better your overall creations will turn out. To get an idea of some of the advanced tricks associated with Photoshop, a few examples are mentioned below:

Photoshop allows advanced users to create digital comic coloring that looks just like the human hand penned it. The tricks and tips associated with this sort of higher-level design deals with the manipulation of various brush sets to achieve the look you desire. Photoshop also lets users create photomontages that can transform an original photograph into something much different.

There are also tips and tricks that can take your most unfavorite picture and alter it in any way you wish. Let’s say you want to change a regular photograph into something dazzling. Advanced Photoshop tricks can beautify a face that displays a natural appearance. In regards to a photo, skin can be fixed, blemishes and wrinkles erased, teeth fixed and whitened, as well as changes made to the eyebrows, hair, and eyes.

When one is able to master advanced Photoshop techniques, the creative possibilities seem never-ending, including 3D glass balls, planet and star-studded skies, matte paintings, and airbrushed illustrations.

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Visit www.photoshoptalent.com for photoshop contest.