That challenge is how to find a robust, efficient and economical way to introduce all these tiny programs to each other, and to alert other programs of their function. Or as Dr Dominik Kuropka, scientific coordinator of the IST-funded Adaptive Services Grid (ASG) project, puts it: "How can we represent the functionality of real world services in a way that computers can deal with it?"
ASG has implemented a reference platform for semantic service provision. Their platform is possibly the first to show that software can autonomously combine functions to achieve some overall goal
Part of that work was to develop a way to represent, in a way machines could understand, the function of each service, such as booking, payment and so on. This is important. Services must be able to advertise their own function, and discover the function of other services.
It enables software to combine and execute independently, without human intervention. A flight service, for example, must be able to understand what a payment service is for before it can invoke it to execute the credit card charge.
Happily, there is a proven, machine-readable method for finding software and objects on the Web using semantics and ontologies. Semantic descriptions outline the nature or function of files and programs in a specific way, based on a lexicon of agreed terms, called an ontology. Vitally, it is machine-readable.
Accurately describing services enables powerful discovery and service composition mechanisms. The challenge facing the creation of an ontology is to find the correct level of granularity. Coarse-grained ontologies are relatively easy to develop, but they result in vague service descriptions making service discovery and composition difficult with a high risk of low precision results, and the need for major human intervention to overcome these drawbacks.
On the other hand, developing fine-grained ontologies is laborious and they come at a cost: extreme complexity. Each field of human endeavour, or domain, needs an ontology specific to it, so you need one ontology for healthcare, another for government and a third for travel. They must cover every type of business information and function for that domain. The number of terms and ontologies mounts quickly. It becomes expensive and time consuming to create and adapt them towards new developments.
Dr Kuropka studied how well services performed at increasingly detailed levels of description. Unsurprisingly, he found that the performance of services improved as the level of detail increased. Less predictable, though, is that the rate of improvement varied at different levels of detail. While performance rises slowly in high and low-levels of detail, Dr Kuropka says that in the middle there appears to be a steep rise in performance.
This is an initial result and Dr Kuropka says the area needs a lot more study, but his observation does suggest that there are particularly cost effective levels of description that may provide a method for balancing costs and benefits.
INFRAWEBS is another IST project in this field that has been developing a framework for open development platforms for Web service-enabled applications using Semantic Web technologies. It took a slightly different, two-step approach to the problem of identifying services.
Instead of one detailed ontology, INFRAWEBS uses a vague ontology to cover a broad area, and highly precise ontologies to cover a smaller number of precise definitions. It increases speed and reduces the complexity tied to the development of ontologies.
"One of the main results is the development of an architecture, which reflects a novel approach for solving problems during the creation of Semantic Web service applications - the tight integration of similarity-based and logic-based reasoning," says Dr HJ Nern, scientific coordinator and Prof G Agre, the senior scientist, of the INFRAWEBS project.
Similarity-based reasoning matches services based on general function, logic-based reasoning uses elaborate logical definitions. "The similarity-based reasoning is used for fast retrieving of an approximate solution, which is further clarified by the logic-based reasoning."
The team also developed a way to use simple expressions in the user interface to create complex logical descriptions of semantic service components. "Such an approach allows a provider of non-semantic Web services to easily become a designer of semantic services, without the need to learn a complex logical language," says Dr Nern. INFRAWEBS also tackled the problem of defining user goals, one of the crucial factors in Web services. If services cannot accurately identify the overall goal, how does it decide what service elements to recruit?
Problems remain. As with the ASG project, the first problem is a level of granularity to be used for creating semantic descriptions of a service. Another serious problem is a lack of commonly accepted ontologies for different domains. "The creation of such general ontologies is not an easy task and in general should be done in conjunction by domain experts and logicians," says Prof Agre. "A consequence of this is the problem of semantic interoperability. That is still an open problem for the Web Service Modelling Ontology community."
It remains a challenge for the development of Semantic Web services but one that experts in the field are actively seeking to resolve.
Tara Morris | alfa
Stanford researchers create new special-purpose computer that may someday save us billions
21.10.2016 | Stanford University
New 3-D wiring technique brings scalable quantum computers closer to reality
19.10.2016 | University of Waterloo
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences