The Hindu Business Line : The fuzzy world of intelligence imitation

Technology is helping us answer questions such as whether it is possible to create a machine that can think. Welcome to the world of Artificial Intelligence.

SOME are wise, and the rest otherwise. There are the haves, and the have-nots, the endowed and the deprived. For those who feel bereft of natural intelligence, there is the AI to help, artificial intelligence, that is. An area that is the preserve of the high-priests, but M. Tim Jones demystifies AI techniques in "Artificial Intelligence Application Programming", a book that covers a wide variety of AI techniques and concepts such as neural networks, genetic algorithms, intelligent agents, rules-based systems, ant algorithms, fuzzy logic, unsupervised learning algorithms, and so on. A sampler of AI:

Many philosophical questions followed the idea of creating an artificial intelligence. For example, is it actually possible to create a machine that can think when we don't really understand the process of thought ourselves? How would we classify a machine being intelligent? If it simply acts intelligent, is it conscious? If an intelligent machine were created, would it be intelligent or simply mimic what we perceive as being intelligent?

Although ants are blind, they navigate complex environments and can find food some distance from their nest and return to their nest successfully. They do this by laying pheromones while they navigate their environment. This process, known as stigmergy, modifies their environment to permit communication between the ants and the colony as well as memory for the return trip to the nest. What is most surprising about this process is that ants tend to take the best route between their nest and some external landmark. Ant algorithms are interesting because they share some of the fundamental qualities of ants themselves. Ants are altruistic, cooperative, and work collectively toward a common goal.

Artificial life, or Alife is a term coined by Chris Langton to describe a wide variety of computational mechanisms used to model natural systems. Artificial life has been used to model agents trading resources in artificial economies, ecologies of insects, the behaviour of animals, and entities negotiating with one another to study models in game theory.

The greatest drawback to rules-based systems is the amount of time spent trying to match a rule with available working memory. A solution to this problem is the Rete algorithm, which shares intermediate information between rules to limit the number of matches that must be performed.

The methods to achieve AI can be divided into two broad categories: top down and bottom up. The top-down category is synonymous with traditional symbolic AI where cognition is a high-level concept and is independent of the lower-level details that implement it. The bottom-up category is synonymous with connectionist AI (neural networks); following closely the model of our own mammalian brains.

Interestingly, AI exploration would reveal more layers of one's own intelligence.

Ants can bite

WE'RE not asking, "Where is Jakarta?" Rather, what is Jakarta? It is an open-source project with emphasis on server-side Java solutions. The Jakarta community has "exploded over the last couple of years with insanely popular - and useful - projects, including Ant, Cactus, and Struts," write Bill Dudney and Jonathan Lehr in "Jakarta Pitfalls: Time-saving solutions for Struts, Ant, JUnit, and Cactus". The technology is new, as are all those novel terms named after small creatures and thorny plants. "Many developers are inexperienced with these tools and are getting trapped by the same pitfalls over and over," say the authors justifying the book. A taster:

A pitfall is a common, overlooked, unsound way of developing and designing software. The consequences of pitfalls vary: Some are as mild as slightly decreased performance, but some have more severe consequences, like slipping schedules, difficult maintenance, and lack of changeability. Cohesive code is easy to follow and understand because it flows logically. Code filled with pitfalls is hard to follow because it does not flow logically.

Console-based testing is the practice of using System.out.println in the test code and then visually inspecting the output to validate that the test subject is doing what it should. Most often, this common practice leads to a numb stare at the console as untold numbers of lines stream by. After some experience with this blank-stare syndrome, developers often resort to putting strange leading and trailing characters into the logs so that the output in question catches the eye.

Actions embody an application's user interface logic. `Struts' defines the Action class as a controller component; therefore, Action implementations should not contain business logic, which properly belongs in model objects. Instead, Actions should confine themselves to responding to user requests, requesting services from the business tier, managing the associated responses, and handling system events.

Ant is a great tool that has replaced make as the build tool of choice for Java developers. It is straightforward, simple to understand, and cross-platform, and it can be extended when necessary with a simple Java class. Even though Ant is easy to pick up, developers still build poorly with it, particularly due to bad planning. For example, the build file can grow over time to include everything that comes up.

If you're still searching for Jakarta on the map, this book isn't for you.

Fix your PIX

FIREWALLS are as much necessary for those trapped with Microsoft products while predatory worms snarl around, as for the jungle campers to ward off the wild animals. A firewall is a device, or a group of devices, that helps you implement your security policies to protect your company against network traffic threats. Thus defines Richard A. Deal in the book Cisco PIX Firewalls - the Ultimate Reference. Cisco's product range covers the SOHO and the large enterprise demands, using the same OS and management tools. The heart of the PIX firewall is the Finesse OS (FOS) and it implements the actual firewall functions that the PIX hardware performs. A few picks:

Using a proprietary OS in a firewall solution makes it much more difficult for hackers to penetrate the firewall. Hackers are very familiar with the functions of common OSs like Unix and Microsoft products.

The PIX is a stateful firewall. So, it adds and maintains information about a user's connection. The Adaptive Security Algorithm (ASA) implements the stateful function of the PIX firewall by maintaining connection information in a connection and translation table, referred to as an xlate table.

One of the main advantages of Network Address Translation (NAT) is that you have an almost inexhaustible number of private addresses at your disposal: over 17 million. When you use private addresses, if you change ISPs, you will not have to re-address your network - you only have to change your translation rules on your translation device. Because all traffic must pass through your translation device to reach your devices with private addresses, you have strict control over what resources, like the Internet, the external users can access on the inside of your network.

Embedding addressing information in the data payload can create problems for address translation devices, such as firewalls. Typically, an address translation device only translates addresses in the IP header and port numbers in the TCP and UDP segment headers - any addressing information embedded in the payload is ignored.

AAA helps you centralise your security checks and is broken into three areas: Authentication (who), authorisation (what) and accounting (when). There are three security protocols used to implement AAA: Kerberos, remote access dial-in user service (RADIUS) and terminal access controller access control system (TACACS+).

Strengthen your firewalls and lock the stables before the data-horses bolt away.

Books courtesy: Wiley Dreamtech India P Ltd. www.wileydreamtech.com)

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