Among the greatest accomplishments of human civilization are bridges. bridges have served as lifelines while inspiring the imaginations of people from early primitive structures where logs were simply positioned across streams to the long, arched spans from the Roman civilization that still stand today, to the modern era's engineering work of art. Bridges enable communication and transportation in times of peace. On the other hand, bridges take on strategic value in times of war. The destruction of bridges has heavily contributed to the outcome of armed conflicts throughout history. A new more sinister kind of warfare was revealed to America trough the 9/11 attacks. Bridges play a critical role in defense strategies in times of war. Hundreds or thousands of casualties, billions of dollars worth of direct reconstruction costs and even greater socio-economic costs can occur with the destruction of a critical bridge or tunnel at one of the numerous choke points in the highway system. The report released by the White House on February 2003, titled "The National Strategy for the Physical Protection of Critical Infrastructures and Key Assets," identifies the close relationship between the many segments of the economy and the nation's transportation infrastructure. Transportation and nearly every other sector of the economy have always and will continue to depend on each other from many aspects. As a result, threats to the transportation operations affect other industries that continue to depend on it. A terrorist attack on any of approximately thousand critical bridges in the United States can result in substantial casualties, economic disruption and other societal ramifications, as reported by a post-9/11 study conducted by Science Applications International Corp. A real life example was the PATH commuter rail line in New York which was not functioning after the attacks of 9/11. The closing of this line affected well over 67,000 passengers for more than two years. Not only that, but this also contributed to the relocation of over a hundred firms, 1.1 million square feet of office space and 11,700 jobs to NJ. These devastating results exemplify the socio-economic loss of a major transportation path. Similarly, the highway infrastructure has vulnerabilities which must be addressed as pointed out by a FHWA's 2003 document, titled "Recommendations for Bridge and Tunnel Security". This issue is so crucial that many individuals would like it to be addressed among the policies of national security. The improvements in homeland security must address enhancements to vital tunnels and bridges. The Coming of Homeland Security
The forefront of highway infrastructure saw little change until the Department of Homeland Security initiated the Surface Transportation and Reliability Act in 2003. On the other hand from the time when the landmark policy shift, DHS has taken far-reaching measures to identify the security needs of the U.S. highway infrastructure, including those of more than six hundred thousand bridges located all throughout the US. March 2003 was the time when the first milestone in the development process took place, this was the time when DHS granted a four-year, $10 million award match to the administration of the Federal Highway department. The main reason for this grant was to develop model security-related installations in several target areas, one of which addresses finding the best approach to carrying out a bridge security network. As a result, the FHWA, allowed state departments of transportation to recommend projects to win the grant and, for the first time in history, they gave the whole grant to a sole bidder which was the Florida Department of Transportation and its valued offer for the iFlorida project. According to an iFlorida program manager the primary mission of the iFlorida model installation is to provide a transportation information infrastructure (or infostructure) to display how security, safety and reliability can be enhanced through extensive accessibility of real-time data. The 'I' in iFlorida resembles the four objectives of the program which are information, intelligence, infrastructure and innovation, at the same time "Infostructure" is a term that blends information and infrastructure for the purpose of enhancing communication and security functionality. Security Control and Administration Security Command and Control is the name of the model bridge security sub-project, it mainly focuses on developing video/software-based recognition systems for two critical Florida bridges, one in the Jacksonville area and one in Orlando. According to another project manager, the major objectives for the video/software-based recognition setup are to enable detection of potential security troubles, assist in preventing disaster-related occurrences, enhance post-event analysis, and assist law enforcement in verifying hit-and-run suspects via footage caught by security cameras. FDOT awarded the Security Command and Control contract to MasTec North America Inc. after realizing that they had a clear picture of what they wanted and who could best help them to achieve their goals. The Director of MasTec's Intelligent Transportation Systems sector turned to security consultant for guidance in product specification and Metric Engineering for help with plans deployment. The approach to integration is one of the innovative aspects of the Security Command and Control system. The detection system which is video/software-based incorporates thermal and active-infrared technology to offer 360 degrees of surveillance for both boat and auto-related traffic for the majority of the time of its operation. PTZ cameras, fixed cameras, and infrared illuminators are installed to supervise specific zones while footage from the cameras is monitored in real-time at the traffic control departments. At the instant that a potential perpetrator or suspicious article is stationary for longer than a preset period of time, an alarm is triggered, the video displays on the monitors and TMC operators become attentive of the potential problem. By utilizing PTZ cameras, TMC operators constantly monitor the bridges and respond to triggered alarm zones. DVRs at field locations capture video footage caught by the cameras at any given instant. The streaming video is sent back via a fiber-optic infrastructure to be monitored at separate TMCs for redundancy as well as maintaining the local recording procedure. Once an alarm is triggered the DVRs at the TMC begin the recording process. The bridges of Jacksonville and Orlando are supervised by operators at both TMCs, as well as by the Florida Highway officers. According to a manager of the project this approach allows for redundancy, which is very beneficial in case the footage is destroyed locally or a TMC is removed from the network. The locations selected for this case study are intentionally different although both bridges cross the channels of major waterways. For instance, the Jacksonville Bridge is particularly urban with underpasses and major intersections to take into consideration. On the other hand, the Orlando area bridge is distinctly rural and most of the traffic below is related to boats. As a consequence, the equipment selection and security goals for the two bridges vary remarkably.

In Linux operating system, you can re-size the hard drive volumes with preservation of your critical data stored on the volume, using Gparted utility. It can also be used for creating, moving and removing hard drive volumes. In some situations, resizing the hard drive volume might cause serious problems of data loss. Unsuccessful operation of disk resizing might render the disk volumes and stored data inaccessible.
In these cases, you are required to opt for effective and powerful Linux Data Recovery software to get all of the missing, lost and inaccessible data. In a practical scenario, when you resize the hard drive volumes using Gparted utility in Linux, read/write operation may halt it and the hard drive might not mount. When you try to access data from the affected hard drive, you come across a number of error messages. In such situations, if you run fsck command to detect and repair errors, it does not detect any problem and you encounter further error messages.

The error message can be similar to the following one:

At this point, your Linux system does not boot up and thus you can not access the stored data form hard drive. In these circumstances, you need to find out the cause of this issue and go for Data Recovery Linux to retrieve lost data.


Cause of this problem
This issue generally occurs due to corruption to the Superblock. It is one of the most critical database of your Linux operating system. The above error message indicates that your file system is severely damaged and thus the system can not work.

Resolution
The Linux operating system keeps redundant copies of superblock. You can use any of them to sort out the problem. You can search alternative superblock using 'mkfs -n' command. If you are unable to replace damaged superblock or the problem is with file system, you can go for hard drive formatting and operating system reinstallation. The process will replace all the damaged system resources and install a clean file system.
Though above process can resolve the current problem, but it also has a drawback. Formatting the hard drive removes all of the data from it and cause critical data loss situations. In these cases, you require Linux Data Recovery to handle the situation. Recovery is best possible using third part Linux Recovery software. The applications use high-end scanning techniques to thoroughly scan the affected drive and retrieve all of the lost, missing and inaccessible data. They are quite easy and safe to use.

Stellar Phoenix Linux Data Recovery is the most excellent solution for all your Linux data loss problems. It supports recovery from Ext4, Ext3, Ext2 and ReiserFS file system volumes. The software is compatible with all major Linux distributions including RedHat, Fedora, Debian and Ubuntu.

DDL (Data Definition Language) statements allow you to alter the data structure of MySQL database components. These statements allow the database user to maintain the records according to some particular requirements. While executing DDL statements is an easy task, the problem arises when MySQL database table indexes gets corrupted or damaged. In such situations, you receive an error message that does not
allow you to perform any DDL operation on the MySQL database components. For complete access of records after such scenarios, you will need to restore MySQL database from an updated backup. But if in case,
no backup is available or backup falls short to restore the required data, then you will need to use advanced mysql database repair
software to comprehensively repair the corrupted database. As a practical instance, when you attempt to insert some records saved in one table to another table, you encounter the below error message: "ERROR 1062: Duplicate ... key"
The above error message prevents the insertion of records from occurring.
Cause
The root cause for the occurrence of the above error message is corruption of table indexes. Corruption in MySQL table indexes can occur due to various reasons like MySQLD head crash, hardware crash, improper
use of MySQL utilities, operating system corruption, virus attacks, and many more similar reasons.
Resolution
To resolve the above error message, you will need to disable the indexes. In most cases, disabling the table indexes resolves the issue and allows you to access your database. However, if the problem persists, then
you will need to use the below repair command:
myisamchk -r -q table_name
But if in case, the above command also fails to perform, then you will need to use a powerful MySQL Database Recovery tool. MySQL Recovery utilities provide safe, complete, and risk-free database repair by
maintaining the intactness of data. These tools use advanced scanning procedures to comprehensively repair the corrupted MySQL databases. With easy understandability, the tools can be used by both technical and
non-technical users.
Stellar Phoenix Database Recovery For MySQL is a professional mysql database recovery software that repairs corrupt MySQL
database (created in both MySQL database storage engines - MyISAM and InnoDB) after almost all corruption scenarios. Supported by Windows Vista, XP, 2003 and 2000, the software safely recovers almost all
MySQL objects like tables, primary key(s), and relations. Compatible with MySQL 5.x, the repair tool provides Windows based recovery from MySQL database installed on Linux platform.

MS Powerpoint is a useful presentation application widely used by business people, students, educators, trainers, etc for preparing presentations. Powerpoint facilitates the use of a consistent style in a presentation using colorful templates. But, in some cases, you might face some issues while trying to access the Powerpoint file. This happens when the Powerpoint file gets corrupted due to virus infection, unexpected system shutdown, power surge, etc. As a result, your valuable data stored in the Powerpoint file becomes inaccessible. An ideal way to overcome such situations is to restore the data from an updated data backup. In case of unavailability of backup, you will need to use an effective Powerpoint Repair software to retrieve your inaccessible data.
For instance - Sometimes, when you try to open a Powerpoint file, you encounter the following error message:

"Sorry, the file cannot be opened because part of the file is missing."

As a result of the above error message, the data saved in the Powerpoint file becomes inaccessible. In addition, you encounter the same error message appears each time you try to access the Powerpoint file.

Cause: Following can be the possible causes responsible for the above error message:

Sudden power failure while Powerpoint was attempting to access the disk. If a virus scanner or other disk utility located the disk while the file was opened in Powerpoint. If you remove the disk ( external storage medium, if any), while the Powerpoint file was open. If you have opened the presentation from a network drive, then a network fault such as a lost connection, while saving, closing or working in a file might be the cause of the above error message. If the presentation is tool large to fit on the disk.

Resolution: To resolve these issues, consider any one of the following measures:

Try to open the file on a different computer. Try to fix the problem by running ScanDisk utility. Try to open a file by a different method. To do so, follow the steps below: 1.Double-click the file in Windows Explorer. 2.Then, start Powerpoint and drag the file from Windows Explorer to Powerpoint. 3.In the last, click Slide from File on the Insert menu in Powerpoint.

However, if the problem persists even after following the above measures, then it is recommended to use a third-party application known as powerpoint recovery software. These are extremely powerful Powerpoint Recovery applications that employ advanced scanning mechanisms to repair the corrupted powerpoint file completely,

Stellar Phoenix Powerpoint Recovery is a comprehensive solution to repair the Powerpoint files such as .ppt and .pptx. The recover powerpoint tool also repairs the PPT file objects such as text, color, font, font name, images, charts, header, footer, etc. The read-only application supports MS Powerpoint 2007, 2003, XP and 2000. The non-destructive tool is compatible with Windows Vista, XP, and 2000 based operating systems.

I should define the word packet before I start. A packet is a message that is sent over the network from one node (Computer) to another node. The packet includes the address of the node that sent the packet, the address of the node the packet is being sent to and data.
I feel that a person that uses networks or wants to understand how they work should at least read about this concept.

It is a "model" because it is a general theory. Defined: O.S.I. stands for Open System Interconnection Reference Model. It is a description of layered communications and computer network protocol design. A protocol is a language need to communicate between one device or piece of hardware and another. It is normally integrated into the operating system of the computer.

The model divides the Network into seven layers. These layers are: Application, Presentation, Session, Transport, Network, Data-Link, and Physical Layers. Each layer provides service to the layer above it.

The seven layers are: 1. Physical - Controls the layout of cables and devices such as repeaters, hubs and Network Interface Cards. 2. Data Link - Provides MAC addresses to uniquely identify network nodes and a means for data to be sent over the physical layer in the form of packets. Bridges and switches are layer 2 devices. 3. Network - Handles routing network messages from one computer to another. 4. Transport - Concerns the transfer of information from one computer to another. The purpose is to that packets are transported reliably and without error. This is where you find the TCP protocol. 5. Session - Establishes sessions between network applications. Session layers include: Simplex, Half-duplex and Full-duplex. 6. Presentation - Converts data so that systems that use different data formats can exchange information. 7. Application - Allows applications to request network services. This layer represents the programming interfaces programs such as Microsoft Office or QuickBooks use to request network services. Some Application Layer protocols include: DNS, FTP,SMTP ,SMB, NFS and Telnet.

The above information may or may not be easy to understand. It is however, a general definition of what every bit and packet of information goes through. It could serve as a means of troubleshooting. If you understand which layer is causing the problem you may be able to zero in on why the network isn't working.



About the Author

Dennis is a Microsoft A+ Certified Technician with over 15 years of experience. He has a very informative computer blog and website that goes into how to solve numerous computer related problems as well as providing general computer tips, reviews and advice. See: http://www.pcinfospace.com

There are different types of Computer Networking that you may need for your home or office. To begin with you have the option of a wired or wireless computer network. These types of networks differ. A wired computer network will have copper or fiber optic cabling running between computers while a wireless network uses radio waves and/or microwaves to maintain communication channels.
A client/server network works by using client devices, typically PCs with network software applications installed that request and receive information over the network. The server device will usually store files and databases and includes more complex applications like Web sites. These devices often feature high-powered central processors, more memory and larger disk drives than the client devices. Two examples of client-server systems include Web browsers and servers.

In addition to these types of networks there are also types of area networks. These are categorized by their scope or scale. Some area network types include:

* LAN - Local Area Network
* WAN - Wide Area Network
* WLAN - Wireless Local Area Network - a LAN based on WiFi wireless network technology
* MAN - Metropolitan Area Network - a network spanning a physical area larger than a LAN but smaller than a WAN, such as a city. A MAN is typically owned an operated by a single entity such as a government body or large corporation.
* CAN - Campus Area Network - a network spanning multiple LANs but smaller than a MAN, such as on a university or local business campus.
* Storage Area Network - connects servers to data storage devices through a technology like Fibre Channel.
* System Area Network - links high-performance computers with high-speed connections in a cluster configuration. Also known as Cluster Area Network.


These are just a few of the various types of area networks. LAN and WAN were the original categories of area networks but through the evolution of technology we have been forced to keep adding more and more types due to the ever-changing field.

A LAN network will connect devices over a relatively short distance. This may include a building, school, or home that will contain a single LAN. Sometimes one building will contain a few small LANs and on the other hand a LAN may span a group of nearby buildings. A WAN spans a large distance. The Internet is the largest WAN as it covers the Earth. A network device called a router will connect LANs to a WAN. These are typically not owned by any one organization like LANs but are under a distributed ownership and management system.

One fine morning Mr. X thought of starting up an Internet Business. But he did not have an apparent idea of the whole matter. He was a little bit of bewildered about the prospect of his business and was about to change his mind for doing something else. Had Mr. X the idea before, he might not have changed his mind. But Internet Business at its base is remarkable alike any other kind of business. The key responsibilities are the same, and the practice pattern is also much alike. Putting up the confidence level of the clientele, truthful yet interesting advertising method, developing long-termed as well as consistent business relationships are among many other essential initiatives to be taken for a good Internet Business setup. However, there are some basic differences between conventional business forms and this one that in the long run pulls up its stature to a different level. Low primary investment: To start an online business, one just needs to pay out a few hundred bucks. All he needs apart from that monetary investment is an innovative idea. But as goes for all other investment, one has to put effort also to get proper return of investment. Internet can not make anyone overnight rich. It demands creativity, proper scheduling, investment and hard labor alongside. Manifold Skill necessities: It's not easy enough for a layman to come and invest and get a high return without proper knowledge about concerned subjects like internet setup, graphic design, web server expertise, programming and marketing strategies to get a boom. To reach that height, one has to assemble experts from various fields to get a positive output. Nonstop marketing potential: The chance and easiness of nurturing strategic deal to reinforce marketing efforts is unrivaled on the internet. Now-a-days, so many corporate associations are being built on the web only because of the reason that the job is becoming more and more simple and lucrative day by day. Easily perceptible results: Another good aspect of Internet Business is that it enables the entrepreneur to get the proper details of the customers individually and as a group very easily. So the growth of the business can be tracked very easily. Hence business strategies are easy to change very often. Global customers: One who is very much home sick and expecting audience only from his or her country can easily expect that the website is surely to get global reach everyday because it is the basic nature of this particular form of business. Hence, one should consider his or her own business from an international viewpoint and should keep other languages apart from English as options. Everything is over and that Mr. X is likely to open a new business on the web, expect high return of his investment and dream high.