SGML and XML are metalanguages - languages for describing other languages - which let users design their own customized markup languages for limitless different types of documents.
SGML is very large, powerful, and complex. It has been in heavy industrial and commercial use for over a decade, and there is a significant body of expertise and software to go with it. XML is a lightweight cut-down version of SGML which keeps enough of its functionality to make it useful but removes all the optional features which make SGML too complex to program for in a Web environment.
HTML is just one of the SGML or XML applications, the one most frequently used in the Web.
The Web is becoming much more than a static library. Increasingly, users are accessing the Web for 'Web pages' that aren't actually on the shelves. Instead, the pages are generated dynamically from information available to the Web server. That information can come from data bases on the Web server, from the site owner's enterprise databases, or even from other Web sites.
And that dynamic information needn't be served up raw. It can be analyzed, extracted, sorted, styled, and customized to create a personalized Web experience for the end-user. To coin a phrase, web pages are evolving into web services.
For this kind of power and flexibility, XML is the markup language of choice. You can see why by comparing XML and HTML. Both are based on SGML - but the difference is immediately apparent:
<p>Apple Titanium Notebook
<br>Local Computer Store
Both of these may look the same in your browser, but the XML data is smart data. HTML tells how the data should look, but XML tells you what it means. With XML, your browser knows there is a product, and it knows the model, dealer, and price. From a group of these it can show you the cheapest product or closest dealer without going back to the server.
Unlike HTML, with XML you create your own tags, so they describe exactly what you need to know. Because of that, your client-side applications can access data sources anywhere on the Web, in any format. New "middle-tier" servers sit between the data sources and the client, translating everything into your own task-specific XML.
But XML data isn't just smart data, it's also a smart document. That means when you display the information, the model name can be a different font from the dealer name, and the lowest price can be highlighted in green. Unlike HTML, where text is just text to be rendered in a uniform way, with XML text is smart, so it can control the rendition.
And you don't have to decide whether your information is data or documents; in XML, it is always both at once. You can do data processing or document processing or both at the same time. With that kind of flexibility, it's no wonder that we're starting to see a new Web of smart, structured information. It's a "Semantic Web" in which computers understand the meaning of the data they share.
A DTD is a formal description in XML Declaration Syntax of a particular type of document. It sets out what names are to be used for the different types of element, where they may occur, and how they all fit together.
The XML Specification explicitly says XML uses ISO 10646, the international standard 31-bit character repertoire which covers most human (and some non-human) languages. This is currently congruent with Unicode and is planned to be superset of Unicode.
Japan is planning a brand new disaster warning system this year. It will be based on social networking sites and has been drafted in the terrible aftermath of the 2011 disasters. One of the major problems in the aftermath of a disaster is coordination and communication. Natural disasters tend to destroy telephone lines and standard emergency lines.
The internet is however a lot more resilient than a fixed copper wire connecting a phone system. There are many ways to connect to the internet and it is virtually impossible to completely destroy it’s infrastructure. We all have different ways to connect and many of us routinely use social networking sites every day.
The test will focus on the most popular social sites in Japan which are Twitter and a local site called Mixi. All these sites can be accessed by computers, laptops, mobile phones and a host of other devices. The test is initially to help create some ground rules for the communication and ensure you don’t end up with things like false disaster reports creating havoc and panic.
Obviously power cuts and broken telecoms infrastructure will still have an impact, but it is hoped that the resilient nature of the internet will be able to overcome some of these difficulties. The scheduled test will simulate a disaster and see how people use their mobiles and other devices to communicate.
There is great hope for these system and using something like Twitter does seem a sensible option for mass communication. There are issues that may have an impact in many countries though not least the increasing number of restrictions that are put on internet access.
There are worries that these filters that require people using proxies which will end up harming some of the advantages of the internet as a communication medium. This combined with the many companies who are imposing blocks and restrictions on a commercial basis. Even public funded companies like the BBC block access to their site – you need to use proxies to watch BBC Iplayer abroad too – see this -
Fortunately Japan does not currently block or censor the internet to any great extent but many countries do. Whether this will pose to be real issue or not is hard to say, but it’s certainly a concern.
Technology is one of the most trending news today. When we hear about technology, we usually spend time to listen about it. We get intrigued when we hear about new technology. With many technologies these days, you probably wanted to have a safe and healthy environment as well. It is important that you don’t forget on the importance of environment once you have a developing society. Perl Critic showed that you can have progressive society even when we are now living in the technology era. You wanted to have an environment that is safe from any materials and items you are using these days. It is probably difficult to believe but most things released and invented have some sort of impacts onto the environment. Green energy is one of the most appreciating and beneficial technology. You can have some ways on how to utilize green energy that would help the environment and your home. Through using the information provided from here, you can have a good and safe environment. You can have good idea of ways in order to switch into green energy.
You can even try setting the air condition to run with 1 degree Celsius warmer throughout the summer and 1 degree Celsius cooler on the winter. Perl Critic can provide you some tips on how to use green energy. This technology really helps many people to save their money from their expenses. You will not notice this difference in temperature and you can save lots of energy and even your money. Additionally, the amount of carbon being utilized would reduce by around 14 percent. It really makes sense once you switch to energy-saving light bulbs from the traditional light bulbs. Don’t wait until your old light bulbs are all burned out. With this, you are saving your money as well as keeping your environment safe and you as well. Also, it is not a good idea to throw away good bulbs just to make the switch; you are also making a way to waste energy. It is very important that you know what you are doing when you really want to save your money. According to some people, the technology negatively affects the life of the people. It makes people lazy. However, this is just an insight to those people who are limited mind.
Perl Critic has started to incorporate green energy sources in your home. You need to cut back the amount of electricity you are using. Ensure that you don’t end up wasting power through leaving things turned on if you are not using them. Through this, you are more efficient with the use of your energy if you make the switch over to substitute energy sources. Recycling can be one of the easy tasks that can make a greener home. Recycling is one of the best ideas to cut the costs of energy. This is one of the reasons why technology plays a big part today. Perl Critic can help you save your money and you can have this through technology.
Ok so the actual day sounds a little contrived, but the Web needs a birthday at some point. So on this exact date, March 12th in 1989 Tim Berners-Lee the British physicist credited with the invention of the web wrote a short memo to his boss.
It was entitled – ‘Information Management: A Proposal’ and it contained details of how he would like to develop a way to share information using a network of computers. He suggested instead of using the standard hierarchical system which was commonly used in the scientific community – a web of individual and linked notes (such as references) could be used.
Two years later the first web pages appeared in 1991 and seven years later nearly 25% of the population of the USA were using the web. It’s a quite staggering take up rate, to reach the same level of penetration for example the Televisions took over a quarter of a century, electricity took over 45 years.
Our children can probably not even envisage life before the world wide web, and perhaps some of us older people feel the same. I’m not even sure how I would go about sorting out my house insurance, booking a holiday or buying christmas presents without the assistance of the internet.
The early days of the web, though were even more exciting, you were never quite sure where you’d stumble across next. Strange technologies like Gopher, FTP, Archie were used to navigate the web and you’d often come face to face with little communities of nerds who seemed lost forever. It’s all very mainstream now and nobody requires even the slightest technological knowledge to get online or find what they need. The only problem is that although the technology has become much more accessible, other forces are starting to put up barriers all the time.
For example do you not think it is incredible that I can sit with my laptop in a cafe barely two miles from the Canadian border and be blocked from watching CTV simply because of my location? Well it’s true, my IP address has determined that I am not allowed to watch the Canadian National News online however if I hop in my car and drive for ten minutes I’ll be fine. In reality people bypass these blocks – by using technology like this – Canadian TV Online
But it doesn’t seem right, not using a system which was designed to facilitate the unrestricted sharing of information for the common good. This situation is being dictated by big business and economics of course, information and media is bought and sold then has restrictions put on it’s use. There is another worry though, the fact that the free and open communication of the web is under even bigger threat from Governments.
Most of the world’s major governments seem involved in various forms of surveillance of the ordinary internet user. If we have used the internet, then we will have been spied on, logs are kept of what we do, what we say and who we speak to online. The reason is usually justified by ‘fighting crime’ or ‘defeating terrorism’ but the problem is that the fundamental democratic nature of the web is being undermined.
The amount of surveillance being undertaken by organisations like MI6 and the FBI is huge and all encompassing with little control of what this data is used for. SO much that for many us the use of security tools which hide our activities and mask our locations by using fake IP addresses seems essential for any level of privacy – like this.
Still the world is certainly a better place for the world wide web and indeed a somewhat smaller one – so happy Birthday !!!
Technology had touches the lives of many people these days. Since people love about something new, they always keep an eye on what would be the next new technology that comes out in the market. This is because they really enjoy how technology makes their lives easier and modern. Yes, when talking about technology, modernity would always be involved. We are now embracing the technology world and that proves that we are now living into the modern world. The fastelavnskostumer has contributed many benefits in our lifestyle. From the traditional and manual works up to the automated works are good explanations on how technology excited the lives of many people. Way back from the past, we use to work manually which is time consuming and so much stressful. But because of technology, those manual works and consumes time task have changed a lot. Technology makes the lives of the people simple and easy. The most affected once regarding technology are the kids.
Since kids love to play, fun and excitement, technology had provided it for them. Kids do love to play and get excite in anything. With technology, they can play using these latest gadgets. Kids do love exciting things and technology has provided them kiddie mini laptops. Kiddie mini laptops have been offered as a product of technology. Kids can experience fast and easy learning. Instead of carrying heavy books for reading activity, they can use kindle reading device. Yes, you can make learning through play for kids. Kids love excitement and fun, once they hold kindle reading device, they would surely be interested to read. The fastelavnskostumer explained how technology changes the lifestyle of the people. Of course, technology doesn’t harm any people as what have other said. Actually, we are the ones who have the mind and who made this technology. Therefore, we must put in mind that these are just material things and have not created without man. Instead of making negative point of view on technology, why not think its benefits provided for us. We always want the best for our kids and we will do everything for them, so there is nothing wrong when we rely on technology as long as we know our limitations on making use of the things.
Kids are not easy to handle especially on the teaching and learning aspect. Therefore, we must be unique on our ideas and ways on teaching for their learning process. With the advancement of technology, it helps a lot. Technology helps teachers to catch the attention of their pupils at school. When you are going to visit kids schools these days, you will witness that there are already technologies that are used in schools for teaching kids. The common technologies in school that have been used by teachers as instructional materials for kids are the computers. Yes, there are lots of schools that have been using computers at school to teach kids how to use it. Hands-on is another effective teaching strategy that will mold the capability of a kid. The fastelavnskostumer as part of technology is really an interesting one.
One of the most important issues that may affect your servers performance is how they deal with DNS. The look ups that your server has to make is something that will affect the speed of your web server or proxy. So in most circumstances, a DNS lookup is used to find the IP address that the server should connect to when retrieving a URL. In many instances this is not an issue, for example if all the content is stored on the local host – then no lookups are required. But often web content contains lots of links and images stored on other servers. For a web server this can affect performance, but for a proxy server it can almost bring the server to it’s knees.
Unfortunately for many servers there’s no solution to performing DNS lookups – basically it’s the way the internet works. For a proxy server it’s even more problematic, for an active connection there will be hundreds of request, both normal and reverse DNS lookups. If you multiply this by a few hundred or even thousand clients then you can imagine the potential impact on your server. The lookups are unavoidable, so to increase performance for DNS and for a server overall you should look at DNS caching.
You should always install this feature whenever possible, it allows a server to internally remember a series of IP addresses in order to resolve requests instantly. It can have a huge affect on performance – the servers can avoid many DNS lookup requests and thus avoid the latency and impact of them. But remember the DNS lookup is only obligatory when the requester actually needs to connect to the source. If you have lost of hosted images from other sites, make sure that your web server load them and doesn’t wait endless requests from other sites.
For proxy servers this stuff is even more important, they’ll get loads more requests. Take for example this instance of a infrastructure of proxy servers designed to encrypt and protect your identity. The security has to be incredibly secure, but in reality people don’t use services that slow their connections down – just look at this video how to find a fast proxy server.
DNS caching can take place anywhere that DNS lookups are required. You can also use it as a tool to protect a server’s resources – for example don’t use up server resources repeatedly looking up bad addresses. Make sure that you install some sort of system that ignores repeated DNS requests for bad servers. If it can’t be resolved and can’t be cached then it should be ignored.
When HTTP authentication is required by a web server, then this authentication takes place for every single request. So for every single request that the web server receives it must decode the message, find the username and passwords then verify these with the ones in it’s user database (if this is the method being used). Naturally this takes a lot of effort and the most obvious result is that of speed, the connection will slow down to allow all this processing.
There are other methods to circumvent this difficulty with HTTP and the most popular is probably the ‘cookie’. What will likely happen is that if a request is received with no authentication credentials and without a cookie then the user receives a 401 request – (401 – is authentication required). The client browser functioning in normal mode, and not the privacy enabled sessions like incognito in Chrome will remember which servers require authentication and which won’t. This enables the client to send the authentication credentials automatically, thereby saving the inconvenience of another 401 response.
Of course there are other authentication methods, for example the securID cards have passwords that change each time, in this case there is no alternative but for the user to enter his password on each request. One of the most common solutions for preventing this is by passing a cookie after a successful authentication request. Any subsequent requests the cookie can be forwarded, most servers will accept this file as a valid authentication credentials.
The information must be secure in the cookie, typically encoded and then verified with an MD5 signature. This stops the cookie being altered or modified in transit, the other information that would be normally included in the file would be
IP Address of Origin
Cookie Expiration Time
Part of this data will be encrypted and other parts like the expiration and IP address will usually be in clear. This clear text data and the MD5 portion of the file can be used to verify the cookie’s validity along with a random string that is generated and passed when the cookie is originally created.
This transparent pass through is important in many applications, a well configured proxy must be able to handle these requests easily. Unfortunately normal cookies cause issues for use with proxies as they are designed to be exchanged between client and server end points. Take for instance this instance where you use a proxy to watch UK TV abroad as in this video -
Using such services might mean that your IP address changes during the connection, which will effectively invalidate the cookie. This means that either the session is disconnected or re-authentication must occur. If the proxy can handle these connections properly then the cookie will remain valid – it can be quite difficult to configure though.
Overall ICMP has been viewed as quite a harmless and perhaps even trivial protocol. However that all changed with the rather nasty Loki. In case you didn’t know Loki is from Norse mythology and he was the god of trickery and mischief. The Loki exploit is well named and seeks to exploit the hither to benign ICMP protocol. ICMP is intended mainly to inform users of error conditions and to make very simple requests. It’s one of the reasons intrusion analysts and malware students tended to ignore the protocol. Of course it could be used in rather obvious denial of service attacks but they were easily tracked and blocked.
However Loki changed that situation as it used ICMP as a tunneling protocol as a covert channel. The definition of a covert channel in these circumstances is a transport method used in either a secret or unexpected way. The transport vehicle is ICMP but Loki acts much more like a client/server application. Any compromised host that gets a Loki server instance installed can respond to traffic and requests from a Loki client. So for instance a Loki server could respond to a request to display the password file to screen or file. That could then be possibly captured and cracked by the owner of the Loki client application.
Many intrusion detection analysts would have simply ignored ICMP traffic passing through their logs. Mainly because it’s such a common protocol but also an such an innocuous one. Of course well read analysts will know treat such traffic with heightened suspicion, Loki really has changed the game for protocols like ICMP.
For those of us who spend many hours watching traffic Loki was a real eye opener. You had to check those logs a little more carefully espcially to watch out for those strange protocols being used in a different context. There’s some more information on these attacks and other technology items here on this video . It can take some finding though !!
Conceptually IP routing is pretty straight forward, especially when you look at it from the hosts point of view. If the destination is directly connected such as a direct link or on the same Ethernet network then the IP datagram is simply forwarded to it’s destination. If it’s not connected then the host simply send the datagram to it’s default router and lets this handle the next stage of the delivery. This simple example illustrates most scenarios.
The basis of IP routing is that it is done on a hop-by-hop basis. The Internet Protocol does not know the complete route to any destination except those directly connected to it. IP routing relies on sending the datagram to the next hop router – assuming this host is closer to the destination until it reaches a router which is directly connected to the destination.
IP routing performs the following -
I) Searches the routing table to see if there is a matching network and host ID. If there is the packet can be transferred through to the destination.
II) Search the routing table for an entry that matches the network ID. It only needs one entry for an entire network and the packet can then be sent to the indicated next hop.
III) If all other searches fail then look for the entry marked – ’default’. The packet then is sent to the next hop router associated with this entry.
If all these searches fail then the datagram is marked undeliverable. In reality most searches will fail the initial two searches and be transferred to the default gateway which could be a router or even a proxy site which forwards to the internet.
If the packet cannot be delivered (usually down to some fault or configuration error) then an error message is generated and sent back to the original host. The two key points to remember is that default routes can be specified for all packets even when the destination and network ID are not known -like this.
The ability to specify specific routes to networks without having to specify the exact host makes the whole system work – routing tables thus contain a few thousand destinations instead of several million!!
Having a bright mind or intelligent minds is the reason why technologies are introduced. Since we are in the society, we must admit the fact that every people have its own ideas, way of thinking, creativity, intelligence and of course skills and talents. Albert Einstein is known as genius. He has an Intellectual Quotient which is very high when compared to other intelligent people. It means that this high intellectual quotient can be the reason why there are many high technology inventions today are introduced in the market. There are nice Baby Clothes today are being offered in the market that comes on different brands and designs. With the advancement of technology, we can have that idea to choose which would be the right one to pick. Technologies are changing and gets more and more innovative. People today usually adapt the advantage of sophisticated lifestyle and that is because of the high IQ of geniuses to be called. Of course, not all genius has the creativity of minds. When both high IQ and creative minds join forces, a masterpiece technology to be called can be created easily. We now have a modern society and that is the reason why we are living in a new modern age of lifestyle.
The simplicity of our lifestyle from the past is actually admiring. We have a peaceful society when we will compare it today. Yet we have admiring society today but there are crimes today happened just because of technologies. It is a fact that not all people in this world are living in a high class family and didn’t belong to a noble family. Those who are less in life get envied to those who can afford and this starts the crime. Those less in life can think negative like stealing of the things they can’t afford in order to own one. This is actually a fact and is happening in the present day. Babytøj is one of the most popular technologies invented today. Many customers are coming back to look the product to have another one. Additionally, the introduction of technology in the society plays a big role in the development of the society and community.
Babytøj is another creation of technology. It is said that this product is best selling in the market recently. It has big discounts especially when you have kids at home. Technology can easily track down the best selling products in the market today. Also, many businesses are relying on technology such as using business tools. Technology contributes these business tools in order to control their business well. Baby Clothes are on the top best selling product in the market. Therefore, manufacturers should products many items of these because many customers are keep on looking the item. Technology has something a lot to do with product creation. We can still produce products with no technology but it is more advantage with the presence of it. Bright minds contribute a lot especially technology. Keep in mind that technology is nothing and did not appeared without brilliant minds. The technology is the fruit of having intelligent mind. Therefore, we must use it brilliantly.
For many years, the rather unfortunate practice of restricting access based on your location has been growing in the online world. In fact any decent web site will now heavily control what you can or can’t see depending on your location. The driver is of course profit, licenses are often granted on a per country basis allowing organisations to maximise their profits by charging different amounts in different places. Those of us who hoped that the internet would become one big global market are set for disappointment.
It was probably to be expected companies have done this for years, charging top dollar in the richer countries whilst lowering their prices in less affluent areas. In fact this forms the very basic laws of economics, check out price discrimination for more reading about this topic. Fortunately though, the technology to apply these restrictions is not very sophisticated at the moment. Basically the website looks up your IP address when you connects and then looks up it’s location, this is used to determine what you can see. For example Hulu holds the US rights to lots of programmes and you can access the whole catalogue if you connect via a US IP address. Connect from anywhere else and you’ll get little more than adverts and a few clips to enjoy.
This was fairly easy to bypass though, just a little research or investment – you could buy proxy servers from a supplier and use it to hide your real address. Slowly this became harder though with companies like Hulu blocking all but the well set up and configured proxies or VPN servers. But there was another problem, changing your connection and using proxies worked great on a computer but nowadays many of us are surfing the web through a host of other devices like games consoles, phones and media streamers like the Roku.
In theory this should work ok too, but suspiciously many hardware manufacturers are putting less access to basic network connectivity on these devices. It’s very hard to get a PS3 or Xbox to use a proxy or shared VPN (although it is possible), and some hardware like the Roku or ADSL routers simply don’t supply access to these sort of configuration options. Which is partly responsible for the next generation of anti-geoblock technology – namely Smart DNS.
This goes a step further than using proxies, or possibly a step backwards in that only part of the connection is redirected (the bit that checks your location), when you start to stream video for example it goes straight from the web server to your PC. This means that obviously the security element of the connection is pretty much non existent. However the video streaming is much quicker as the majority of the traffic doesn’t need to be router through a third party which happens when using a proxy or VPN server.
SGML and XML are both languages that are used for defining markup languages. More specifically, they are metalanguage formalisms that facilitate the definition of descriptive markup languages for the purpose of electronic information encoding and interchange. SGML and XML support the definition of markup languages that are hardware- and software-independent, as well as application-processing neutral.
SGML is an International Standard, defined in the document ISO 8879:1986. Information Processing - Text and Office Systems - Standard Generalized Markup Language (SGML), as amended. A key philosophical commitment underlying SGML is separating the representation of information structure and content from information processing specifications. Information objects modeled through an SGML markup language are named and described (using attributes and subelements) in terms of what they are (from a defined perspective) not in terms of how they are to be displayed or otherwise processed.
XML (Extensible Markup Language) is a dialect of SGML that is designed to enable 'generic SGML' to be served, received, and processed on the World Wide Web. XML originated in 1996, as a result of frustration with the deployment of SGML on the Internet. The SGML family of standards that include SGML (the modeling framework), DSSSL (the transformation framework for presentation) and HyTime (the linking and timing framework) are ISO standards that proved difficult to implement and aroused little interest outside of specialist fields of expertise. XML simplified the requirements for implementation, with the specific intention of enabling deployment of markup applictions on the Internet.
Both SGML and XML supported by a suite of companion standards addressing such features as transformation, presentation, linking, and event triggering. A broad range of commercial and public-domain software has been developed to assist users with markup implementation.