Try these…
Green alien: =:)
Rose: @};-
Skull: 8-X
Man: <):)
Smily -throw up: :-&
Smily -shhhhh: :-$
Pig: :@)
Monkey: :()
Smily -pouting: [-(
Light bulb: *-:)
American flag: **==
Friday, February 8, 2008
GLOBAL WARMING – DO WE NEED TO CARE?
How many of us hear the words global warming, climate change, etc but choose to ignore them, thinking that they do not affect us? Is this burying your head in the sand kind of behaviour right? Most of the youngsters that I talk to do know what global warming is, they do know that it is causing climate changes...but most often the thinking is that – “why should I care, it’s not going to effect me in my life time!”. Well, here’s a wakeup call - It’s not one day that climate change will happen, it is happening right here and right now. Do not believe me, well then, take a look for yourself at these facts and decide for yourself.
Drowning Polar Bears
Polar Bears have been found drowned in the arctic as receding ice defeats their swimming skills. Summer ice has shrunk by more than a quarter in the past fifty years thus reducing the polar bears’ habitat. Some researchers studying the animals have even reported that the polar bears may be eating each other for a lack of their usual diet of seals.
Bears in Spain
Bears in Spain have stopped hibernating for the winter — and the cause could be climate change. Many of the 130 bears in Spain's northern mountains who usually sleep through the cold season are still active because milder weather means they have enough nuts and berries to survive.
Genetic Changes in flies
Global warming is leading to widespread genetic changes in some species of flies. A very small change in temperature, about ½ degrees centigrade, which seems very trivial, is not trivial to the flies.
Migrating Fishes and Insects
A warm water Atlantic triple fin fish has, for the first time been caught, off the coast of Britain, in another sign of species migrating North. Recent high temperatures have drawn a number of exotic moth species to the UK and butterfly experts predict further migration as part of a permanent trend brought on by global warming.
Barn Owls in the Arctic
Barn Owls, robins, hornets and other temperate species are arriving in the Arctic for the first time.
Snows of Mount Kilimanjaro
More than eighty percent of the snow on Mount Kilimanjaro has melted away.
This is just an indication of what's to come. Climate change is impacting on the natural world. “Hitherto the warming seemed to be happening fastest at the Poles — now we're getting examples of it happening further south."
In India, this July, 400 Open-Bill Storks built nests, paired, mated. And in August because of shortage of rainfall, all nests were abandoned. This is no freak incident. With the weather increasingly playing spoilsport in many parts of the country, the flora and fauna seem to be bearing the brunt. Last year mango trees in Andhra Pradesh flowered three months early because of rising heat. A few years ago, bees in the Himalayas were impacted by similar erratic flowering patterns, leading to a big drop in the honey supply. Locals have also reported a marked decline in the population of Swallows in Srinagar valley. In fact, rising temperatures in Delhi have even resulted in the near disappearance of some species of birds. Certain frog species are perhaps the most vulnerable to weather changes. With rainfall and temperature built into their lifecycle, erratic rainfall disrupts their breeding pattern.
Scientists have reason to believe that all of the above unnatural changes have been brought about as a direct consequence of, hold your breath.., GLOBAL WARMING. But how many of us know what it is, what causes it and what can we do to reduce the effect?
Well, Global Warming is a significant increase in the Earth’s climatic temperature over a relatively short period of time as a result of the activities of human beings. The greenhouse effect happens because of certain naturally occurring substances in the atmosphere. Sine the Industrial Revolution, humans have been pouring huge amount of these substances like Carbon Dioxide, Methane, Nitrous Oxide, etc. into the air. Power plants, Cattle and Cars are the major contributors of greenhouse gases such as carbon dioxide and methane.
As responsible citizens there are some simple things each of us can do to help decrease greenhouse gas emissions. Some of these include:
· Turn lights and other appliances off when you are not using them. Even though a light bulb does not generate greenhouse gas, the power plant that generates the electricity does (especially in India where we still rely on fossil fuels to generate electricity).
· Switch from incandescent light bulbs to fluorescent bulbs, which use less energy and last longer.
· Walk or ride to work if possible. Vehicles burn fossil fuel, so less use reduces carbon dioxide emissions.
· Recycle. Garbage that doesn’t get recycled ends up in a landfill generating methane. Also, recycled goods also require less energy to produce than products made from scratch.
· Plant trees and other plants where you can as they take carbon dioxide out of the air and release oxygen.
· Do not burn garbage. This releases carbon dioxide and hydrocarbons into the atmosphere.
Lets not forget that – “We have not inherited the earth from our parents; we have borrowed it from our children”.
Think of your planet as a person you love, Remember, the earth is a living being. Treat it as one and bring about a greener, healthier world for yourself and to secure your future generations.
Drowning Polar Bears
Polar Bears have been found drowned in the arctic as receding ice defeats their swimming skills. Summer ice has shrunk by more than a quarter in the past fifty years thus reducing the polar bears’ habitat. Some researchers studying the animals have even reported that the polar bears may be eating each other for a lack of their usual diet of seals.
Bears in Spain
Bears in Spain have stopped hibernating for the winter — and the cause could be climate change. Many of the 130 bears in Spain's northern mountains who usually sleep through the cold season are still active because milder weather means they have enough nuts and berries to survive.
Genetic Changes in flies
Global warming is leading to widespread genetic changes in some species of flies. A very small change in temperature, about ½ degrees centigrade, which seems very trivial, is not trivial to the flies.
Migrating Fishes and Insects
A warm water Atlantic triple fin fish has, for the first time been caught, off the coast of Britain, in another sign of species migrating North. Recent high temperatures have drawn a number of exotic moth species to the UK and butterfly experts predict further migration as part of a permanent trend brought on by global warming.
Barn Owls in the Arctic
Barn Owls, robins, hornets and other temperate species are arriving in the Arctic for the first time.
Snows of Mount Kilimanjaro
More than eighty percent of the snow on Mount Kilimanjaro has melted away.
This is just an indication of what's to come. Climate change is impacting on the natural world. “Hitherto the warming seemed to be happening fastest at the Poles — now we're getting examples of it happening further south."
In India, this July, 400 Open-Bill Storks built nests, paired, mated. And in August because of shortage of rainfall, all nests were abandoned. This is no freak incident. With the weather increasingly playing spoilsport in many parts of the country, the flora and fauna seem to be bearing the brunt. Last year mango trees in Andhra Pradesh flowered three months early because of rising heat. A few years ago, bees in the Himalayas were impacted by similar erratic flowering patterns, leading to a big drop in the honey supply. Locals have also reported a marked decline in the population of Swallows in Srinagar valley. In fact, rising temperatures in Delhi have even resulted in the near disappearance of some species of birds. Certain frog species are perhaps the most vulnerable to weather changes. With rainfall and temperature built into their lifecycle, erratic rainfall disrupts their breeding pattern.
Scientists have reason to believe that all of the above unnatural changes have been brought about as a direct consequence of, hold your breath.., GLOBAL WARMING. But how many of us know what it is, what causes it and what can we do to reduce the effect?
Well, Global Warming is a significant increase in the Earth’s climatic temperature over a relatively short period of time as a result of the activities of human beings. The greenhouse effect happens because of certain naturally occurring substances in the atmosphere. Sine the Industrial Revolution, humans have been pouring huge amount of these substances like Carbon Dioxide, Methane, Nitrous Oxide, etc. into the air. Power plants, Cattle and Cars are the major contributors of greenhouse gases such as carbon dioxide and methane.
As responsible citizens there are some simple things each of us can do to help decrease greenhouse gas emissions. Some of these include:
· Turn lights and other appliances off when you are not using them. Even though a light bulb does not generate greenhouse gas, the power plant that generates the electricity does (especially in India where we still rely on fossil fuels to generate electricity).
· Switch from incandescent light bulbs to fluorescent bulbs, which use less energy and last longer.
· Walk or ride to work if possible. Vehicles burn fossil fuel, so less use reduces carbon dioxide emissions.
· Recycle. Garbage that doesn’t get recycled ends up in a landfill generating methane. Also, recycled goods also require less energy to produce than products made from scratch.
· Plant trees and other plants where you can as they take carbon dioxide out of the air and release oxygen.
· Do not burn garbage. This releases carbon dioxide and hydrocarbons into the atmosphere.
Lets not forget that – “We have not inherited the earth from our parents; we have borrowed it from our children”.
Think of your planet as a person you love, Remember, the earth is a living being. Treat it as one and bring about a greener, healthier world for yourself and to secure your future generations.
Monday, February 4, 2008
Ontologies in the Semantic Web
In order for information from different sources to be integrated, there needs to be a shared understanding of the relevant domain. Knowledge representation formalisms provide structures for organizing this knowledge, but provide no mechanisms for sharing it.
An ontology defines a common vocabulary for researchers who need to share information in a domain. It includes machine-interpretable definitions of basic concepts in the domain and relations among them. An ontology is a formal explicit description of concepts in a domain of discourse (classes (sometimes called concepts)), properties of each concept describing various features and attributes of the concept (slots (sometimes called roles or properties)), and restrictions on slots (facets (sometimes called role restrictions)). An ontology together with a set of individual instances of classes constitutes a knowledge base.
In practical terms, developing an ontology includes:
- defining classes in the ontology,
- arranging the classes in a taxonomic (subclass–superclass) hierarchy,
- defining slots and describing allowed values for these slots,
- filling in the values for slots for instances.
According to Gruber’s definition an ontology is “a formal specification of a conceptualization”. A conceptualisation being a simplified, abstract way of perceiving a segment of the world (a piece of
reality), for which we agree to recognize the existence of a set of objects and their interrelations, as well as the terms we use to refer to them and their agreed meanings and properties.
Some of the reasons to develop an ontology are:
· To share common understanding of the structure of information among software agents
· To enable reuse of domain knowledge
· To make domain assumptions explicit
· To separate domain knowledge from the operational knowledge
· To analyze domain knowledge
An ontology defines a common vocabulary for researchers who need to share information in a domain. It includes machine-interpretable definitions of basic concepts in the domain and relations among them. An ontology is a formal explicit description of concepts in a domain of discourse (classes (sometimes called concepts)), properties of each concept describing various features and attributes of the concept (slots (sometimes called roles or properties)), and restrictions on slots (facets (sometimes called role restrictions)). An ontology together with a set of individual instances of classes constitutes a knowledge base.
In practical terms, developing an ontology includes:
- defining classes in the ontology,
- arranging the classes in a taxonomic (subclass–superclass) hierarchy,
- defining slots and describing allowed values for these slots,
- filling in the values for slots for instances.
According to Gruber’s definition an ontology is “a formal specification of a conceptualization”. A conceptualisation being a simplified, abstract way of perceiving a segment of the world (a piece of
reality), for which we agree to recognize the existence of a set of objects and their interrelations, as well as the terms we use to refer to them and their agreed meanings and properties.
Some of the reasons to develop an ontology are:
· To share common understanding of the structure of information among software agents
· To enable reuse of domain knowledge
· To make domain assumptions explicit
· To separate domain knowledge from the operational knowledge
· To analyze domain knowledge
What is the Semantic Web?
The World Wide Web has emerged as an important part of our everyday lives in the last decade. People use the web to share information; companies use it to advertise their products; government organizations use it to make everyday submission of taxes and bill easier; people use e-groups to facilitate information exchange within their community and educational institutions use the web to deliver teaching material and online training.
This has resulted in widespread popularity of the web and as a result, the number of pages available in the global information space has grown exponentially. This makes it extremely difficult for users to locate and access information that they require. When one needs to search the Web for some specific information, it results in a large number of hits in the form of search results that have to be scanned and filtered manually to get at the desired information. The number of matches is so large that the specific information required may even be missed.
Since the meaning, i.e. - the semantics of the information is not understood by machines, it is difficult for machines to extract information of relevance for human use from weakly structured HTML documents. Besides this, data can be shared between applications only via cut and paste because the way in which data is stored in web pages, the semantics of the data is lost; the web pages do not carry any semantic information along with the data.
Therefore, in recent years, the awareness to these problems has resulted in a need for information in the web to be structured in such a way that the semantics of the data be accessible to machines. The information must be semantically annotated so that software agents and desktop applications can directly access and process it. In other words, the current web needs to be augmented so that the semantics of the Web pages is machine-process able.
Tim Berners-Lee the originator of the Web sees the Semantic Web as an extension of the current web in which information is given well defined meaning, better enabling computers and people to work in cooperation. The meaning of the information on a Web page is formalized using semantic meta-data that is based on concepts defined in ontologies.
The Semantic Web is the future of the World Wide Web. It is a cooperative effort to build an architecture for the World Wide Web by formatting the content in terms of metadata so that it can be understood by a software agent. The web as it stands now contains vast amounts of information, all of which has been structured for human consumption. The idea behind the semantic web is to provide structure to this information so that it can be read and interpreted by a computer. An agent can visit a page which has been extended with metadata and understand the kind of data contained in that page and then use it to make inferences or decisions about what to do with that data. It enables the agent to respond to unforeseen situations.
Users often want to use the Web to do more than just locate a document, they want to perform some task. For example, a user might want to find the best price on a desktop computer, plan and book a family vacation to a distant city, or make reservations at a moderately-priced Indian restaurant within five kilometers of the movie they plan to see that evening. Completing these tasks often involves visiting a series of pages, integrating their content and reasoning about them in some way. This is far beyond the capabilities of contemporary directories and search engines.
The main obstacle is the fact that the Web was not designed to be processed by machines. Although, web pages include special information that tells a computer how to display a particular piece of text or where to go when a link is clicked, they do not provide any information that helps the machine to determine what the text means. Thus, to process a web page intelligently, a computer must understand the text, but natural language understanding is known to be an extremely difficult and unsolved problem. Some researchers and web developers have proposed that we augment the Web with languages that make the meaning of web pages explicit. Tim Berners-Lee, inventor of the Web, has coined the term Semantic Web to describe this approach. The Semantic Web is not a separate Web but an extension of the current one, in which information is given well-defined meaning, better enabling computers and people to work in cooperation.
This has resulted in widespread popularity of the web and as a result, the number of pages available in the global information space has grown exponentially. This makes it extremely difficult for users to locate and access information that they require. When one needs to search the Web for some specific information, it results in a large number of hits in the form of search results that have to be scanned and filtered manually to get at the desired information. The number of matches is so large that the specific information required may even be missed.
Since the meaning, i.e. - the semantics of the information is not understood by machines, it is difficult for machines to extract information of relevance for human use from weakly structured HTML documents. Besides this, data can be shared between applications only via cut and paste because the way in which data is stored in web pages, the semantics of the data is lost; the web pages do not carry any semantic information along with the data.
Therefore, in recent years, the awareness to these problems has resulted in a need for information in the web to be structured in such a way that the semantics of the data be accessible to machines. The information must be semantically annotated so that software agents and desktop applications can directly access and process it. In other words, the current web needs to be augmented so that the semantics of the Web pages is machine-process able.
Tim Berners-Lee the originator of the Web sees the Semantic Web as an extension of the current web in which information is given well defined meaning, better enabling computers and people to work in cooperation. The meaning of the information on a Web page is formalized using semantic meta-data that is based on concepts defined in ontologies.
The Semantic Web is the future of the World Wide Web. It is a cooperative effort to build an architecture for the World Wide Web by formatting the content in terms of metadata so that it can be understood by a software agent. The web as it stands now contains vast amounts of information, all of which has been structured for human consumption. The idea behind the semantic web is to provide structure to this information so that it can be read and interpreted by a computer. An agent can visit a page which has been extended with metadata and understand the kind of data contained in that page and then use it to make inferences or decisions about what to do with that data. It enables the agent to respond to unforeseen situations.
Users often want to use the Web to do more than just locate a document, they want to perform some task. For example, a user might want to find the best price on a desktop computer, plan and book a family vacation to a distant city, or make reservations at a moderately-priced Indian restaurant within five kilometers of the movie they plan to see that evening. Completing these tasks often involves visiting a series of pages, integrating their content and reasoning about them in some way. This is far beyond the capabilities of contemporary directories and search engines.
The main obstacle is the fact that the Web was not designed to be processed by machines. Although, web pages include special information that tells a computer how to display a particular piece of text or where to go when a link is clicked, they do not provide any information that helps the machine to determine what the text means. Thus, to process a web page intelligently, a computer must understand the text, but natural language understanding is known to be an extremely difficult and unsolved problem. Some researchers and web developers have proposed that we augment the Web with languages that make the meaning of web pages explicit. Tim Berners-Lee, inventor of the Web, has coined the term Semantic Web to describe this approach. The Semantic Web is not a separate Web but an extension of the current one, in which information is given well-defined meaning, better enabling computers and people to work in cooperation.
What are the advantages of Multi Agent Systems?
A MAS has several advantages as opposed to a single agent system. Some of them are elaborated upon below:
- A MAS is decentralized, that is, there no one single point of control. The agents constituting the MAS perform their tasks independently but are able to achieve goals because they communicate and collaborate amongst themselves. Being a distributed system, all problems related to resource limitation, performance bottlenecks, critical failures are avoided.
- If the sources of information are geographically distributed, a MAS is able to retrieve, selectively extract and globally coordinate information from distributed sources.
- The system performance is enhanced because a MAS is more reliable, maintainable, flexible, reusable, robust and extensible as compared to a single agent system.
What is a Multi Agent System (MAS)?
A multi-agent system (MAS) is a loosely coupled network of software agents that interact to solve problems that are beyond the individual capacities or knowledge of each problem solver.
Multi-Agent systems are open information systems that contain multiple autonomous agents or agents acting on behalf of autonomous users or entities. Complex problems require the services of multiple agents with diverse capabilities and needs e.g., the mediator based approach to information systems.
A Multi-Agent System (MAS) is a system composed of a population of autonomous agents, which cooperate with each other to reach common objectives, while simultaneously each agent pursues Individual objectives.
A Multi-Agent system is able to solve tasks; the agents must communicate amongst themselves and coordinate their activities. If a MAS lacks communication and coordination, the end result is going to be chaos.
There are several reasons why multiple agents need to be coordinated :
- Prevent chaos. No agent possesses a global view of the entire agency to which it belongs, as this is simply not feasible in any community of reasonable complexity. Consequently, agents have only local views, goals and knowledge that may interfere with rather than support other agents' actions. Coordination is vital to prevent chaos during conflicts.
- Meet global constraints. Agents performing network management may have to respond to certain failures within seconds and others within hours. Coordinating agents; Behavior is therefore essential to meet such a goal.
- Agents in MAS possess different capabilities and expertise. Therefore, agents need to be coordinated in just the same way that different medical specialists, including anesthetists, surgeons, ambulance personnel, nurses, etc., need to coordinate their capabilities to treat a patient.
The characteristics of MAS are that
1. Each agent has incomplete information or capabilities for solving the problem and, thus, has a limited viewpoint
2. There is no system global control
3. Data are decentralized
4. Computation is asynchronous
Multi-Agent systems are open information systems that contain multiple autonomous agents or agents acting on behalf of autonomous users or entities. Complex problems require the services of multiple agents with diverse capabilities and needs e.g., the mediator based approach to information systems.
A Multi-Agent System (MAS) is a system composed of a population of autonomous agents, which cooperate with each other to reach common objectives, while simultaneously each agent pursues Individual objectives.
A Multi-Agent system is able to solve tasks; the agents must communicate amongst themselves and coordinate their activities. If a MAS lacks communication and coordination, the end result is going to be chaos.
There are several reasons why multiple agents need to be coordinated :
- Prevent chaos. No agent possesses a global view of the entire agency to which it belongs, as this is simply not feasible in any community of reasonable complexity. Consequently, agents have only local views, goals and knowledge that may interfere with rather than support other agents' actions. Coordination is vital to prevent chaos during conflicts.
- Meet global constraints. Agents performing network management may have to respond to certain failures within seconds and others within hours. Coordinating agents; Behavior is therefore essential to meet such a goal.
- Agents in MAS possess different capabilities and expertise. Therefore, agents need to be coordinated in just the same way that different medical specialists, including anesthetists, surgeons, ambulance personnel, nurses, etc., need to coordinate their capabilities to treat a patient.
The characteristics of MAS are that
1. Each agent has incomplete information or capabilities for solving the problem and, thus, has a limited viewpoint
2. There is no system global control
3. Data are decentralized
4. Computation is asynchronous
What Is an Agent?
An Agent is a software entity or a logical model that acts autonomously, without any user intervention. It has the ability to react to its environment and make decisions. Agents are not activated per se but they activate themselves as and when the need arises. Agents carry further the concept behind Object Oriented Development. Objects are defined by their data and their methods. Agents are used in Component Oriented development and are defined by their behavior.
An Agent has the following characteristics:
An Agent has the following characteristics:
- Purposeful : is goal driven and pro active
- Reactive : as opposed to deliberative; performs tasks in response to actions
- Autonomous : does not need human intervention for decision making or achievement of goals
- Communication Ability : capability of coordination with other agents in the neighborhood to work towards solution of a problem
- Collaborative : works collectively to achieve a goal; as in Multi-agent systems
- Adaptability : perceive the context in which they operate and react to it appropriately
- Learning Ability: ability to learn from past experiences and make intelligent decisions based on that
- Evolvable: ability to alter behavior in response to environment
Various agents in literature have been developed to perform the following tasks:
· Personal information assistants
· Data Mining
· Mail Filtering
· Travel Planning
· Interface provider
· Meeting Scheduler
· Information Broker
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